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Δευτέρα 17 Δεκεμβρίου 2018
Panafrican Medical Journal
Indian Journal of Occupational and Environmental Medicine (Indian J Occup Environ Med) 2018 | September-December | Volume 22 | Issue 3
| Occupational health surveillance Damodar Vishnu Lele Indian Journal of Occupational and Environmental Medicine 2018 22(3):117-120,
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| The untold story of fluoridation: Revisiting the changing perspectives Maitreyee P Unde, Raju Umaji Patil, Persis P Dastoor Indian Journal of Occupational and Environmental Medicine 2018 22(3):121-127 The discovery of fluoride in dentistry has revolutionized treatment modalities with a new aspect of prevention and conservation of tooth structure coming into foreplay. Since then, there has been a lot of research on both topical and systemic fluoridation in an overzealous attempt to control the most debilitating dental problem of caries. Although topical fluoride is still being widely used as a preventive measure for dental caries, systemic administration of the same has gained major criticism worldwide due to the low margin of safety of fluoride and no control over the amount of individual intake when administered on a community level. This problem is more prevalent in countries with presence of natural fluoride belts that extend from Turkey to China and Japan through Iraq, Iran, and Afghanistan increasing the chances of both dental and skeletal fluorosis and hence increasing the focus toward defluoridation. This historical review highlights the distribution of fluoride worldwide and in India and also discusses about the various claims of the antifluoride lobby. | ||||||||||
| Occupational and environmental exposure to lead and reproductive health impairment: An overview Sunil Kumar Indian Journal of Occupational and Environmental Medicine 2018 22(3):128-137 Lead is a heavy metal. It is used in lead-acid battery, as a coloring agent, paints, and metal alloyed as shielding materials, smelters, printing press, and so on. It is a toxic metal affecting various organs, and developing fetus and young children are more vulnerable to toxicity of lead. This overview is based on the information of toxic potential of lead to human reproduction and reproductive outcome. Exposure to lead may affect libido, semen quality by declining sperm count, motility, viability, integrity, elevation in morphological abnormalities, and sperm DNA integrity. These alterations led to reducing fertility potential and chances of miscarriages, preterm birth, and so on in a partner. Lead exposure impairs hormonal synthesis and regulations in both sexes. Lead exposure also affects female reproduction by impairing menstruations, reducing fertility potential, delaying conception time, altering the hormonal production, circulation, affecting pregnancy and its outcome, and so on. At present, the safe dose of lead cannot be advocated as more and more data are generated in recent years which indicate the toxic potential of lead to human reproduction at a low level that was previously thought not to have such effect. Hence, use of lead should be stopped/avoided or restricted to safeguard human reproduction. | ||||||||||
| Upper extremity muscular strength in push–pull tasks: Model approach towards task design Joydeep Majumder, Sanjay M Kotadiya, Lokesh Kumar Sharma, Sunil Kumar Indian Journal of Occupational and Environmental Medicine 2018 22(3):138-143 Background: Pushing and pulling in workplaces are common actions. Repetitive forceful exertions in long-duration works lead to increased risk of musculoskeletal disorders and injuries. Aim: To investigate the upper extremity strength in generic push–pull modes while using hand tools and forecasting the limits of the workers while frequent or continuous operation. Settings and Design: The study was conducted among men workers in Ahmedabad city, India, and the design was cross-sectional study. Materials and Methods: In all, 100 men were recruited (Group 1: 18–39 years and Group 2: 40–60 years). Upper extremity muscular strength (isometric mode) testing of the preferred hand during push–pull type of manual hand-tool operations was carried out for 60 s. Forecasting of strength to generate predictions for future events (120 s) based on known past events (measured 60 s) was carried out using Holt–Winters time-series model. Statistical Analysis: Descriptive statistics was used for analysis. For prediction model evaluation, WEKA 3.8.2 was used. Results: Anthropometric parameters of both groups were similar, having no effect on generated strength. Largely, pull strength was recorded to be higher than push strength, wherein Group 2 men generated slightly higher strength. Seated strength was also higher than standing exertion. Forecasting reveals steady strength values for Group 1 men, whereas steep decline among Group 2 men with increasing duration of trial. Conclusion: The strength data generated would aid in work schedule design. Strength forecasting model would assist in developing engineering guidelines in the design of tools at workplace. | ||||||||||
| Effects of occupational heat exposure on traffic police workers in Ahmedabad, Gujarat Amee Raval, Priya Dutta, Abhiyant Tiwari, PS Ganguly, LM Sathish, Dileep Mavalankar, Jeremy Hess Indian Journal of Occupational and Environmental Medicine 2018 22(3):144-151 One of the most concerning environmental effects of climate change is rising levels of extreme heat, which already poses serious risks in many parts of the world. In June and July 2015, we collected weekly heat exposure data using area and personal temperature monitoring in Ahmedabad, Gujarat. The study was conducted at four different traffic junctions with a cohort of 16 traffic police. For information on health effects, we administered a baseline survey at the start of the study and prospectively followed up with the officers on prevalence of heat-related symptoms. Wet bulb globe temperature (WBGT) levels ranged from 28.2°C to 36.1°C during the study period. Traffic police workers who participated in this study were exposed to WBGT levels higher than the recommended threshold limit value as per American Conference of Governmental Industrial Hygienists guidelines even beyond the hottest months of the season. Our findings suggest that airport measurements by the Indian Meteorological Department may not accurately capture heat exposures among individuals who work in and alongside high-density traffic junctions. Based on our temperature estimates, traffic police are at risk for heat stress. India is likely to experience warmer temperatures and increased heat waves in the coming decades, fueled by climate change. Therefore, it is important to reduce current and future heat-related risks for traffic police workers and similar occupational risk groups by establishing protection strategies. The protocol established in this study for occupational heat exposure assessment could be applied to a larger cohort. | ||||||||||
| The exposure to pollutants of the auto repair workers: Monitoring their oxidative stress Roberto Menicagli, O Marotta, L Menicagli Indian Journal of Occupational and Environmental Medicine 2018 22(3):152-155 Background and Aim: Auto repair workers are exposed to multiple pollutants, each of them potentially risks, dangerous for several target organs. The aim of this study is to identify their possible overall effect, by monitoring the concentration of salivary malondialdehyde, index of oxidative stress. Materials and Methods: Malondialdehyde of 25 male workers, smokers and non-smokers, further divided into two subgroups relatively to the amplitude of their working place, was monitored, in the saliva, with the Thiobarbituric acid method. The control group consists of 12 and 13 male smokers, and 13 non-smokers. Univariate (UVA) and Multivariate (MVA) analysis methods were used to analyze the results. Results: No variable is significant (P ≥ 0.05) for the control group using UVA, while age and smoking significantly increase the levels of MDA (P ≤ 0.05) using MVA. For workers group, the age and the place of work increase the MDA (P ≤ 0.05) using UVA analysis, while only the place of work remains significant (≤0.05) using MVA analysis. MVA analysis reveals that, besides the type of work, also the age and smoking significantly increase the level of MDA, as a result of a higher exposure to pollutants. Conclusions: You can check the cumulative effect of pollutants on auto repair workers, by monitoring the salivary malondialdehyde. | ||||||||||
| Impact of school air quality on children's respiratory health Peter Fsadni, Frank Bezzina, Claudia Fsadni, Stephen Montefort Indian Journal of Occupational and Environmental Medicine 2018 22(3):156-162 Background: Asthma is common in children with indoor pollutants influencing the development of the disease. Since children spend most of their time outside their homes within the school environment, school indoor air quality can directly influence their respiratory health. Aims: This study aims to analyze the indoor and outdoor air quality of Maltese schools and if an association exists between indoor pollutants and respiratory health in children. Settings and Design: Five primary schools were selected with 9- to 11-year-old students participating. Materials and Methods: Standardized health questionnaires and lung function tests were utilized. Indoor and outdoor air sampling together with traffic counts were carried out. Statistical Analysis Used: SPSS version 21 was used and the Chi-squared, logistic regression, and Pearson's correlation were used. Results: The mean indoor PM 2.5 level of 17.78 μg/m3 and CO (9.11 ppm) exceeded World Health Organization thresholds. Indoor ozone levels exceeded the mean European school's indoor ozone concentration of 8 μg/m3. High exposure to formaldehyde, NO2, and ozone was associated with atopy in children. Heavy vehicles passing near the schools were associated with current wheezing (P < 0.001) but not nocturnal cough (P = 0.34). Conclusions: School indoor and outdoor environment has a direct impact on children's respiratory health. This study has identified significant associations between high exposures to indoor air pollutants, school characteristics, and upper and lower airway inflammation. | ||||||||||
| Work related musculoskeletal disorders and postural stress of the women cultivators engaged in uprooting job of rice cultivation Amitava Pal, Prakash C Dhara Indian Journal of Occupational and Environmental Medicine 2018 22(3):163-169 Aims: A large number of workers including women are involved in the informal sector in India. A majority of them are engaged in agricultural sectors. The agricultural workers have to perform their jobs by putting manual labor and are exposed to different occupational stresses. The present study was aimed to evaluate postural stress and prevalence of musculoskeletal disorder (MSD) of women cultivators engaged in uprooting job of rice cultivation. Settings and Design: This cross-sectional study was conducted on 166 women cultivators from different districts of West Bengal state, India. Materials and Methods: Prevalence and intensity of MSDs of the cultivators were evaluated by Nordic questionnaire and 10-point body part discomfort scale. Work rest pattern and postural pattern were studied by direct observation method. Postural stress was assessed by OVAKO Working Postures Analysis System (OWAS), Rapid Entire Body Assessment (REBA), Rapid Upper Limb Assessment (RULA), and Quick Exposure Checklist (QEC) methods and as well as by measuring center of gravity. Results and Conclusions: MSD was highly prevalent among the study participants. Lower back, hip, wrist, shoulder, and knee were highly affected. Higher prevalence of MSDs among the cultivators may be because of prolonged working hours and awkward postures. The women cultivators had to start their day before dawn to finish off their household chores such as cooking, cleaning, washing clothes and dishes, etc., before they moved off to the fields, which altogether impose them under additional stress. It may be suggested that ergonomic interventions such as modifying work-rest schedules, improving work postures, and introducing new design hand tools should be considered for improving work condition of the women cultivators. | ||||||||||
| A comparative study of byssinosis in jute industries Asim Saha, Anirban Das, Bhaskar Prasad Chattopadhyay, Jane Alam, Tilak Kanti Dasgupta Indian Journal of Occupational and Environmental Medicine 2018 22(3):170-176 Background: Byssinosis is an acute respiratory difficulty that is caused usually following exposure to cotton and hemp dust. Occurrence of such similar acute symptoms had been reported following exposure to jute dust/fiber also. With passage of time, Jute industries have modernized themselves for increased quality and productivity, which has lessened workforce and thereby provided more working space. However, occupational health benefit due to such changes has rarely been explored. This study was initiated to understand whether this modernization can protect the health of workers. Methodology: This study was carried out in two jute mills manufacturing jute clothes, jute bags, and so on. Interview of the workers for their occupational and morbidity details, medical examinations, as well as pre-shift and post-shift pulmonary function tests was carried out. Results: It was observed that chest tightness was significantly more in the industry with old technologies. Breathlessness was also more in this industry. As far as pulmonary function status is concerned, it was noted that greater than 5% cross-shift change in forced expiratory volume in one second was more common in the industry with old technology. Obstructive feature on lung function test was also observed in workers of both industries. Conclusion: The study concluded that exposure to jute dust has contributed to both acute and chronic respiratory health effects in the jute industry workers. Modernized industry showed lesser prevalence of acute symptoms and changes related to byssinosis. Modernization of processes in jute industries may prove fruitful in lowering the respiratory problems of workers. | ||||||||||
| Nipah virus: South India in panic mode Jasmine Shanthi Kamath, Shruthi Hegde, Vidya Ajila Indian Journal of Occupational and Environmental Medicine 2018 22(3):177-178 |
An increase of estrogen receptor α protein level regulates BDE-209-mediated blood-testis barrier disruption during spermatogenesis in F1 mice
Abstract
Deca-bromodiphenyl ether (BDE-209) regulates various aspects of spermatogenesis and male fertility through its effect on estrogen receptor α (ERα), but the underlying mechanism remains unclear. Because molecular mechanisms such as remodeling of the blood-testis barrier (BTB) play crucial roles in spermatogenesis, we investigated the disruptive effects of ERα agonists on the BTB in spermatogenesis. In this study, 0, 300, and 500 mg/kg/day of BDE-209 were administered to pregnant adult mice by oral gavage from gestation day 7 to postnatal day 21. SerW3 cells were treated with methylpiperidino pyrazole (MPP) for 30 min before being treated with 50 μg/mL of BDE-209. BDE-209 increases ERα in time- and dose-dependent manners and decreases formin 1 and BTB-associated protein in F1 male mice. Furthermore, BDE-209 impairs the structure and function of the BTB. Activation of ERα signaling could disrupt the BTB, leading to spermatogenesis dysfunction. The results identified the role of ERα in BTB disruption during spermatogenesis and suggested that BTB disruption occurs because of exposure to BDE-209, which could potentially affect spermatogenesis. In conclusion, Sertoli cells seem to be the primary target of BDE-209 in the perinatal period, and this period constitutes a critical window of susceptibility to BDE-209. Also, the SerW3 cell model may not be a particularly useful cell model for studying the function of the cytoskeleton.
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Stabilization and cyclic utilization of chrome leather shavings
Abstract
For the sake of the safe and efficient cyclic utilization of chrome leather shavings (CLS), the temporary stabilization of CLS during the storage and transport processes was optimized. Afterwards, the large-scale stabilized CLS degradation and collagen degradation product (CDP) extraction were completed. In this research, hydroxyapatite (HAP) and calcium hydroxide (Ca(OH)2) were for the first time used as stabilizers in the stabilization of CLS. The results showed that both Ca(OH)2 and HAP displayed resistance to chrome leaching, but HAP provided better stabilization effect than Ca(OH)2. The optimized stabilization conditions giving lower chromium leaching concentration were selected: 2% HAP, temperature 300 °C, reaction time 60 min, and initially added water contents of 50%. The reason for HAP and Ca(OH)2 stabilization was proved by energy dispersive X-ray spectroscopy (EDS). Subsequently, the exploitation value of the stabilized CLS was described by large-scale experiment. The hydrolysis of stabilized CLS could obtain the collagen degradation product (CDP), which had 3.52% of free amino content and a molecular weight of 3.4~30 kDa. The filter residue was treated by 5% sulfuric acid solution extraction and pressure filtration again. The extraction solution and final filter residue were dried separately to obtain chromium-containing organic compounds (COP) and industrial gypsum. The COP, used as a filling for tannery, contains 9.37% Cr2O3 content and 90.6% organic content. The industrial gypsum contains 68.37% CaSO4, 0.13% Cr2O3, and 31.5% residual organic or inorganic compounds, which can be used in building materials. No waste water or solid waste was discharged in this experiment process.
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Kinetic, equilibrium, and thermodynamic studies on the adsorption of ciprofloxacin by activated carbon produced from Jerivá ( Syagrus romanzoffiana )
Abstract
High specific surface area activated carbon prepared from endocarp of Jerivá (Syagrus romanzoffiana) (ACJ) was used for ciprofloxacin (CIP) antibiotic removal from aqueous effluents. The activated carbon (AC) was characterized via scanning electron microscope, Fourier transform infrared spectroscopy, N2 adsorption/desorption, and pH value at the zero-charge point. Avrami kinetic model was the one that best fit the experimental results in comparison to the pseudo-first-order and pseudo-second-order kinetic models. The equilibrium data obeyed the Liu isotherm equation, showing a maximum adsorption capacity of 335.8 mg g−1 at 40 °C. The calculated thermodynamic parameters indicate that the adsorption of CIP was spontaneous and endothermic at all studied temperatures. Also, the free enthalpy changes (∆H° = 3.34 kJ mol−1) suggested physical adsorption between CIP and ACJ. Simulated effluents were utilized to check the potential of the ACJ for wastewater purification. The highly efficient features enable the activated carbon prepared from endocarp of Jerivá, an attractive carbon adsorbent, to remove ciprofloxacin from wastewaters.
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Evaluation of Possible Human Health Risk of Heavy Metals from the Consumption of Two Marine Fish Species Tenualosa ilisha and Dorosoma cepedianum
Abstract
In order to study the effects of contaminants on human health, fish is considered as a powerful model among all available species for risk-benefit assessments. Tenualosa ilisha and Dorosoma cepedianum are two fish species of great economic importance as they are found in undeveloped, developing and developed countries. Concentrations of heavy metals lead (Pb), cadmium (Cd), chromium (Cr), arsenic (As) and mercury (Hg) were determined using validated and accredited test methods in order to assess the potential human health risk from the dietary intake of these two selected fish species. The estimated daily intake (EDI) of all the five heavy metals was measured from the consumption of the two species considering the mean fish consumption of 61 g person−1 day−1 defined for European population. The EDI indicates that no risk to people's health with respect to the EDI of Pb, Cd, Cr, As and Hg through the consumption of the two fish species. The estimation of target hazard quotient (THQ) demonstrating the non-carcinogenic risk indicates that intake of Pb, Cd, Cr and Hg through the consumption of two fish species is safe for human health, whereas, consumption of As suggests potential risk to consumers. The estimation of carcinogenic risk of Cd, Cr and As due to the consumption of two selected fish species indicates that consumers remain at risk of cancer. Thus, these fish species should not be considered safe for human consumption.
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A review of studies on urban energy performance evaluation
Abstract
Energy is a foundation for a city to create economic wealth, satisfy people's desires, and achieve benefits. However, the increasing mismatch between energy supply and demand and the worsening of environmental pollution have highlighted the importance of improving urban energy performance, so the number of studies related to urban energy performance evaluation is increasing. Based on describing the authors, numbers, regional sources, and themes of these studies, this paper reviews and analyzes the conceptions, evaluation indicators, influencing factors, evaluation methods, and evaluation systems related to urban energy performance. Most countries have expressed concern about this topic. Researchers in China, Belgium, and the USA have had the most achievements and collaborations. The concept of urban energy performance further extends to a comprehensive performance. It is measured based on an input-output process. In addition to the original evaluation indicators, new desirable outputs and undesirable outputs are included. Industrial structure, energy price, population density, home car ownership, climate factors, Gini coefficient, health expenditure level, and unemployment rate are regarded as influencing factors. Therefore, a new framework of evaluation indicators and influencing factors is constructed. Stochastic frontier analysis (SFA) and data envelopment analysis (DEA) are commonly used to evaluate. With changes in conceptions, evaluation indicators, and influencing factors, the evaluation method should rather focus on measuring multiple input-output variables, determining the evaluation results and the impacts of factors at the same analysis stage, and highlighting policy orientations. As an important management tool, the evaluation system would continue to be studied and developed.
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Influence of electronic cigarette vaping on the composition of indoor organic pollutants, particles, and exhaled breath of bystanders
Abstract
The changes of particles and organic pollutants in indoor atmospheres as consequence of vaping with electronic cigarettes have been analyzed. Changes in the composition of volatile organic compounds (VOCs) in exhaled breath of non-smoking volunteers present in the vaping environments have also been studied. The exposure experiments involved non-vaping (n = 5) and vaping (n = 5) volunteers staying 12 h together in a room (54 m2) without external ventilation. The same experiment was repeated without vaping for comparison. Changes in the distributions of particles in the 8–400 nm range were observed, involving losses of nucleation-mode particles (below 20 nm) and increases of coagulation processes leading to larger size particles. In quantitative terms, vaping involved doubling the indoor concentrations of particles smaller than 10 μm, 5 μm, and 1 μm observed during no vaping. The increase of particle mass concentrations was probably produced from bulk ingredients of the e-liquid exhaled by the e-cigarette users. Black carbon concentrations in the indoor and outdoor air were similar in the presence and absence of electronic cigarette emissions. Changes in the qualitative composition of PAHs were observed when comparing vaping and non-vaping days. The nicotine concentrations were examined separately in the gas and in the particulate phases showing that most of the differences between both days were recorded in the former. The particulate phase should therefore be included in nicotine monitoring during vaping (and smoking). The concentration increases of nicotine and formaldehyde were small when compared with those described in other studies of indoor atmospheres or health regulatory thresholds. No significant changes were observed when comparing the concentrations of exhaled breath in vaping and no vaping days. Even the exhaled breath nicotine concentrations in both conditions were similar. As expected, toluene, xylenes, benzene, ethylbenzene, and naphthalene did not show increases in the vaping days since combustion was not involved.
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Evaluating the utility of human glucagon-like peptide 1 receptor gene as a novel radionuclide reporter gene: a promising molecular imaging tool
Abstract
Radiolabelled ligands of glucagon-like peptide 1 receptor (GLP-1R) have been used to image the GLP-1R-expressing tissues (e.g., islets and insulinoma). Here, we introduced human glucagon-like peptide 1 receptor (hglp-1r) gene as a novel radionuclide reporter gene to broaden its applications in molecular imaging in vivo. Transient and stable baculoviral vectors (BV) were re-constructed and used to transfer the hglp-1r gene or enhanced green fluorescent protein (egfp) reporter gene into the stem cells or tumor cells. Cell proliferation assay and flow cytometry analysis demonstrated that BV-mediated reporter gene transferring and expression was biosafe and highly efficient. The BV-mediated exogenous hGLP-1R in target cells showed same ligand-receptor binding characteristics compared with its counterpart in insulinoma cells. Furthermore, the ligand-receptor binding assay showed a high affinity (IC50 = 0.3708 nM) and robust correlation (R2 = 0.9264) between the fluorescein-tagged or radiolabeled ligand probes and exogenous hGLP-1R in target cells. The target cells transferred with BV-mediated hGLP-1R could be clearly visualized in nude mice by micro-PET, which was capable of the purposes of short-term tracking transplanted stem cells or long-term monitoring tumor formation. Then, the image-based analysis and bio-distribution analysis quantitatively confirmed high target-to-background ratio of hGLP-1R-expressing cells. This study also investigated the endogenous GLP-1R-expressing organs/tissues in nude mice in the hGLP-1R radionuclide reporter gene imaging. Summarily, we evaluated the utility of hglp-1r gene as a novel radionuclide reporter gene, and demonstrated that it was a favorable and promising candidate of molecular imaging tool, which would expand the spectrum of radionuclide reporter gene imaging systems.
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Production and extraction of carotenoids produced by microorganisms
Abstract
Carotenoids are a group of isoprenoid pigments naturally synthesized by plants and microorganisms, which are applied industrially in food, cosmetic, and pharmaceutical product formulations. In addition to their use as coloring agents, carotenoids have been proposed as health additives, being able to prevent cancer, macular degradation, and cataracts. Moreover, carotenoids may also protect cells against oxidative damage, acting as an antioxidant agent. Considering the interest in greener and sustainable industrial processing, the search for natural carotenoids has increased over the last few decades. In particular, it has been suggested that the use of bioprocessing technologies can improve carotenoid production yields or, as a minimum, increase the efficiency of currently used production processes. Thus, this review provides a short but comprehensive overview of the recent biotechnological developments in carotenoid production using microorganisms. The hot topics in the field are properly addressed, from carotenoid biosynthesis to the current technologies involved in their extraction, and even highlighting the recent advances in the marketing and application of "microbial" carotenoids. It is expected that this review will improve the knowledge and understanding of the most appropriate and economic strategies for a biotechnological production of carotenoids.
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Ammonia Synthesis Under Ambient Conditions: Selective Electroreduction of Dinitrogen to Ammonia on Black Phosphorus Nanosheets
Constructing efficient catalysts for the N2 reduction reaction (NRR) is a major challenge for artificial nitrogen fixation under ambient conditions. Herein, inspired by the principle of "like dissolves like", we demonstrate that, a member of the nitrogen family, well‐exfoliated few‐layer black phosphorus nanosheets (FL‐BP NSs) can be used as an efficient nonmetallic catalyst for electrochemical nitrogen reduction. The catalyst can achieve a high ammonia yield of 31.37 μg h‐1 mg‐1cat. under ambient conditions. Density functional theory calculations reveal that the active orbital and electrons of zigzag and diff‐zigzag type edges of FL‐BP NSs enable selective electrocatalysis of N2 to NH3 via an alternating hydrogenation pathway. This work proves the feasibility of using a nonmetallic simple substance as a nitrogen‐fixing catalyst and thus opening a new avenue towards the development of more efficient metal‐free catalysts.
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Structural and Electronic Effects of Stepwise Reduction of a Tetraaryl[3]Cumulene
The chemical reduction of a [3]cumulene ([3]TrTol) is explored using alkali metals. Mono‐ and doubly‐reduced forms of [3]TrTol are isolated as solvent‐separated ion pairs (SSIP) with {Na(18‐crown‐6)}+ and {K(18‐crown‐6)THF2}+ counter ions and crystallographically characterized. This allows analysis of structural parameters of the "naked" anions of [3]TrTol without interference from metal binding. The dianion of [3]TrTol is also isolated as a contact‐ion complex with {Cs(18‐crown‐6)}+ cations, adding the effect of metal coordination to the core. Structural comparisons of anions to the neutral molecule, [3]TrTol, outline monotonic increases in bond‐length alternation (BLA) upon step‐wise reduction. The greatest BLA value is found for contact‐ion complex, which shows an alternating sequence of short and long carbon‐carbon bonds consistent with structure of an alkyne. The cumulenic framework remains planar in all derivatives, contrasting studies of tetraphenyl[3]cumulene.
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Peripheral Insulin Extraction in Non-Diabetic Subjects and Type 2 Diabetes Mellitus Patients
Exp Clin Endocrinol Diabetes
DOI: 10.1055/a-0808-4029
Background Insulin has to be transported across the capillary endothelium to stimulate muscle glucose uptake. We investigated insulin uptake from the peripheral circulation in non-diabetic (ND) individuals and in type 2 diabetes (T2D) patients. Methods Single-center cross-sectional study involving 40 ND (age 65±11 years) and 30 T2D patients (age 67±8 years). Thirty-six participants were studied in the fasted state (22 ND subjects and 14 T2D patients termed NDF and T2DF) and 34 participants 1-h following a glucose challenge (18 ND subjects and 16 T2D patients indicated as NDG and T2DG). Main outcome measure was fractional extraction (FE) of insulin and glucose using the forearm balance method. Results In NDF, FEins was 18 (10–26)% at lower insulin levels (63 51–80] pmol/l), while in NDG at higher insulin levels (776 [543–1176] pmol/l), FEins was 9 (4–16)% (p=0.01 vs. NDF). In NDF only, a negative correlation was observed between FEins and arterial plasma insulin load (rho=−0.575;p=0.006) and fasting plasma glucose levels (rho=−0.551;p=0.01). In T2DF FEins was 6 (1–19)% and not different from FEins in T2DG (10 2–14)%), and was not associated to fasting glucose. FEins tended to be higher in NDF compared to T2DF (p=0.07). Discussion We propose that in non-diabetic individuals, besides passive diffusion, an active high-affinity pathway with limited capacity around lower physiologic insulin levels exists for insulin transendothelial transport, contributing to glycemic control. In T2D patients, this mechanism of peripheral insulin uptake is diminished or even absent. Modulation of insulin extraction from the circulation may be a novel target to improve glucose metabolism in T2D.
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© Georg Thieme Verlag KG Stuttgart · New York
Article in Thieme eJournals:
Table of contents | Abstract | Full text
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Adherence to Therapeutic Footwear in Type 2 Diabetes in Malta
Exp Clin Endocrinol Diabetes
DOI: 10.1055/a-0808-4111
Background The literature reports that people living with diabetes do not adhere to their prescribed therapeutic footwear as instructed. The reason for this is still uncertian although certain footwear characteristics seem to reasons reported leading to reduced level of adherence. Objectives To explore the reasons for current adherence or otherwise to prescribed stock footwear amongst patients living with type-2 diabetes. Methods An exploratory qualitative design method using an Interpretative Phenomenological Analysis [IPA] was employed in this research. Employing purposive sampling, twelve participants were recruited and interviewed. Interviews were recorded, transcribed and later analysed. Results Common themes that emerged from this study fell under 2 main categories including 'Adherence' and 'Non – Adherence' to wearing the prescribed stock footwear. A number of themes were identified with regards to the reasons for such adherence or otherwise by respective participants including footwear characteristics, service provision, peer pressure and the patient's knowledge and attitudes. Conclusion This study demonstrated suboptimal adherence to wearing therapeutic footwear among people with type 2 diabetes. Although the literature highlights the importance of adherence to therapeutic footwear in high risk populations for the prevention of diabetic foot complications, this study provides the reasons as to why patients still do not comply in wearing their prescribed therapeutic footwear. In order to improve behavioral changes patients would require on-going care, empowerment and support combined with educational programs to achieve a higher level of adherence. More research is warranted to explore further psychosocial interventions in diabetes care.
[...]
© Georg Thieme Verlag KG Stuttgart · New York
Article in Thieme eJournals:
Table of contents | Abstract | Full text
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High‐Pressure Synthesis of A2NiO2Ag2Se2 (A=Sr, Ba) with a High‐Spin Ni2+ in Square‐Planar Coordination
All in a spin: A high‐pressure reaction allows the synthesis of A2NiO2Ag2Se2 (A=Sr, Ba) with a square‐planar NiO2 sheet. These materials (and Cu/Mn analogues) have extremely long Ni−O (Cu/Mn−O) bonds owing to an extensive strain from AgSe layers, enabling an otherwise missing S=1 square‐planar state. The distinct compressibility between oxide and chalcogenide layers accounts for this phenomenon.
Abstract
Square‐planar coordinate Ni2+ ions in oxides are exclusively limited to a low‐spin state (S=0) owing to extensive crystal field splitting. Layered oxychalcogenides A2NiIIO2Ag2Se2 (A=Sr, Ba) with the S=1 NiO2 square lattice are now reported. The structural analysis revealed that the Ni2+ ion is under‐bonded by a significant tensile strain from neighboring Ag2Se2 layers, leading to the reduction in crystal field splitting. Ba2NiO2Ag2Se2 exhibits a G‐type spin order at 130 K, indicating fairly strong in‐plane interactions. The high‐pressure synthesis employed here possibly assists the expansion of NiO2 square lattice by taking the advantage of the difference in compressibility in oxide and selenide layers.
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Catalytic Asymmetric Epoxidation of Aldehydes with Two Different Borate Catalysts of VANOL
Abstract. A highly diastereoselective and enantioselective method for the epoxidation of aldehydes with α‐diazoacetamides has been developed with two different borate ester catalysts of VANOL. Both catalytic systems are general for aromatic, aliphatic and acetylenic aldehydes giving high yields and inductions for nearly all cases. One borate ester catalyst has two molecules of VANOL and the other only one VANOL. Catalysts generated from BINOL and VAPOL are ineffective catalysts. An application is made to the side‐chain of taxol.
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Quantifying the Initial Unfolding of Bacteriorhodopsin Reveals Retinal Stabilization
The forces that stabilize membrane proteins remain elusive to precise quantification. Particularly important but poorly resolved are the forces present during a membrane protein's initial unfolding, where the most native set of interactions are present. We developed a high‐precision, atomic force microscopy assay to study the initial unfolding of bacteriorhodopsin. We discovered rapid near‐equilibrium folding between the first three unfolding states that corresponded to the unfolding of 5 and 8 amino‐acids respectively when using a cantilever optimized for 2‐µs resolution. Interestingly, the third of these states was retinal stabilized and previously undetected despite being the most mechanically stable state in the whole unfolding pathway, supporting 150 pN for >1 min. We expect that this ability to measure the rapid and reversible dynamics in the initial unfolding of bacteriorhodopsin provides a platform for quantifying the energetics of membrane proteins under native‐like conditions.
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Conductive Fused Porphyrin Tapes on Sensitive Substrates by a Chemical Vapor Deposition Approach
Oxidative polymerization of nickel(II) 5,15‐diphenyl porphyrin and nickel(II) 5,15‐bis(di‐3,5‐tert‐butylphenyl) porphyrin by an oxidative chemical vapor deposition (oCVD) approach yields multiply fused porphyrin oligomers in thin film form. The oCVD technique enables the formation, deposition and p‐doping of conjugated poly(porphyrins) coatings in a single step without the use of solvents or post‐treatments. The decisive reactions and side reactions during the oCVD process are evidenced by high‐resolution mass spectrometry. Due to the highly conjugated structure of the fused porphyrin tapes the thin films exhibit an electrical conductivity of 3.6×10–2 S·cm–1 and strong absorption in the visible to near‐infrared spectral region. The formation of smooth conjugated poly(porphyrins) thin films, even on sensitive substrates, is demonstrated by their successful deposition and patterning on glass, silicon and printer paper. The ability to form conductive poly(porphyrins) thin films could enable the design of a new category of optoelectronic devices using the oCVD approach.
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Nature of Hydrogen Adsorption on Platinum in the Aqueous Phase
The thermodynamic state of H₂ adsorbed on Pt in the aqueous phase was determined by kinetic analysis of H₂ reacting with D₂O to HDO, HD and D₂ and by DFT based ab inito molecular dynamic simulation of H2 adsorption on Pt (111), Pt (110), and Pt nanoparticles. Dissociative adsorption of H₂ on Pt is significantly weakened in the aqueous phase compared to adsorption at gas‐solid interface. Water destabilizes adsorbed H, decreasing the heat of adsorption by 19 − 22 kJ/mol(H₂), while inducing an additional entropy loss of 50 − 70 J/(mol(H₂)·K). Upon dissociative H₂ adsorption, the averaged distance of water from the Pt surface increases and it assumes a more ordered structure. In turn, the more ordered water layer limits the translation mobility of adsorbed H. The presence of hydrated hydronium ions next to Pt further reduces the H‐Pt bond strength.
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Alkyne Reactivity Preferred over Ynamide: Regioselective Radical Cyclization of Yne‐Ynamides
Ynamides are typically more reactive than simple alkynes and olefins. However, a serendipitous observation revealed a rare case where the reactivity of simple alkynes exceeds that of ynamides. This led to the development of a unique sulfur radical‐triggered cyclization of yne‐tethered‐ynamides, which involves the attack of a thiyl radical to the alkyne and then that of the ynamide. A wide range of novel 4‐thioaryl pyrroles that could tolerate common functional moieties and N‐protecting groups were expediently constructed by this strategy. The current method opposes to the typical cyclization of yne‐ynamides, which involves the attack of the ynamide core to the alkyne moiety. Control experiments and DFT calculations supported the participation of the sulfur radical in the reaction and the regioselective cyclization. The synthetic potential of the substituted pyrroles is also discussed.
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Transformation of Imine Cages to Hydrocarbon Cages
In contrast to organic cages which are formed by exploiting dynamic covalent chemistry, such as boronic ester cages, imine cages or disulfide cages, those with a fully carbonaceous backbone are rarer. With the exception of alkyne metathesis based approaches, the vast majority of hydrocarbon cages needs to be synthesized by kinetic bond formation. This implies a multiple step synthesis and no correction mechanism in the final macrocyclization step ‐ both responsible for low overall yields. Whereas for smaller cages the intrinsic drawbacks are not always obvious, larger cages are seldom synthesized in yields beyond a few tenth of a percent. Here we present a three‐step method to convert imine cages into hydrocarbon cages. This has been successfully applied even for larger structures such as derivatives of C72H72 – an unknown cage suggested by Fritz Vögtle more than 20 years ago.
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Azo‐MICs: Redox‐Active Mesoionic Carbene Ligands Derived from Azoimidazolium Dyes
Azoimidazolium dyes were used as precursors for mesoionic carbene ligands (Azo‐MICs). The properties of these ligands were examined by synthesizing RhI, AuI, and PdII complexes. Experimental (NMR, IR) and theoretical investigations show that Azo‐MICs are potent σ‐donor ligands. Yet, they feature a small singlet‐triplet gap and very low‐lying LUMO levels. The unique electronic properties of Azo‐MICs allow for reversible one‐electron reductions of the metal complexes, as evidenced by cyclic voltammetry.
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Bioinspired Radical Stetter Reaction: Radical Umpolung Enabled by Ion‐Pair Photocatalysis
A bioinspired radical Stetter reaction of α‐keto acids and aldehydes has been designed that is contingent on a formal "radical umpolung" concept. In their Communication (DOI: 10.1002/anie.201809601), R. Gilmour and co‐workers synergise organo‐ and photocatalysis activation principles to expand the mechanistic and synthetic scope of the classic Stetter reaction to include α,β‐unsaturated aldehyde acceptors, and thus solve a longstanding chemoselectivity problem.
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Selective Formation of an FeIVO or an FeIIIOOH Intermediate From Iron(II) and H2O2: Controlled Heterolytic versus Homolytic Oxygen–Oxygen Bond Cleavage by the Second Coordination Sphere
Don't cleave me this way: A novel synthetic iron(II) complex bearing a second sphere intra‐molecular base efficiently forms an iron(IV)‐oxido species in the presence of H2O2 rather than the usual formation of an FeIII species. Mechanistic studies demonstrate an overall heterolytic cleavage of the O−O bond proceeding by a homolytic cleavage with a concerted proton coupled electron transfer (PCET).
Abstract
We demonstrate that the devised incorporation of an alkylamine group into the second coordination sphere of an FeII complex allows to switch its reactivity with H2O2 from the usual formation of FeIII species towards the selective generation of an FeIV‐oxo intermediate. The FeIV‐oxo species was characterized by UV/Vis absorption and Mössbauer spectroscopy. Variable‐temperature kinetic analyses point towards a mechanism in which the heterolytic cleavage of the O−O bond is triggered by a proton transfer from the proximal to the distal oxygen atom in the FeII‐H2O2 complex with the assistance of the pendant amine. DFT studies reveal that this heterolytic cleavage is actually initiated by an homolytic O−O cleavage immediately followed by a proton‐coupled electron transfer (PCET) that leads to the formation of the FeIV‐oxo and release of water through a concerted mechanism.
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Decarboxylative ipso Amination of Activated Benzoic Acids
Up in the air: An oxidative decarboxylative coupling of benzoic acids with unprotected amines has been achieved using bimetallic Pd/Cu catalysis. This simple aniline synthesis only requires air or NMO as an oxidant, is amenable to multigram scale, and allows orthogonality to traditional Pd‐catalyzed cross‐couplings. Mechanistic investigations suggest the intermediacy of a hypervalent Pd species.
Abstract
In the presence of a bimetallic Pd/Cu system with 1,10‐phenanthroline as the ligand and either air or N‐methylmorpholine N‐oxide as the oxidant, electron‐deficient benzoic acids undergo oxidative decarboxylative coupling with unprotected amines. This operationally simple aniline synthesis is widely applicable with respect to the amine and gives good yields, even on multigram scale. The orthogonality of this reaction to other Pd‐catalyzed cross‐couplings allows the concise synthesis of multisubstituted arenes by sequential C−C, C−Cl, and C−N functionalizations. Mechanistic investigations suggest the intermediacy of a hypervalent Pd species.
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Well‐Arranged and Confined Incorporation of PdCo Nanoparticles within a Hollow and Porous Metal–Organic Framework for Superior Catalytic Activity
Well‐dispersed and ultrafine bimetallic PdCo nanoparticles are confined within a unique hollow and porous ZIF support by the one‐step pyrolysis of polystyrene@ZIF‐67/Pd2+ core–shell microspheres. The pyrolysis process involves several simultaneous chemical conversions and the resulting composite (PdCo@HZIF) displays superior catalytic activity.
Abstract
A convenient method for the confined incorporation of highly active bimetallic PdCo nanocatalysts within a hollow and porous metal–organic framework (MOF) support is presented. Several chemical conversions occur simultaneously during the one‐step low temperature pyrolysis of well‐designed polystyrene@ZIF‐67/Pd2+ core–shell microspheres, where ZIF (zeolitic imidazolate framework) is a subclass of MOF: the polystyrene core is removed, resulting in a beneficial hollow and porous ZIF support; the ZIF‐67 shell acts as a well‐defined porous support and as a felicitous Co2+ supplier for metal nanoparticle formation; and Pd2+ and Co2+ are reduced to form catalytically active bimetallic PdCo nanoparticles in the well‐defined micropores, inducing the confined growth of PdCo nanoparticles with excellent dispersity.
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Autonomic Behaviors in Lipase‐Active Oil Droplets
Up and down: A new protocell model based on enzyme‐powered oil droplets capable of self‐consumption, feedstock regeneration, oscillatory temperature‐guided contraction, and reversible buoyancy‐induced motility is described as a step towards autonomic behavior in life‐like microscale objects.
Abstract
Developing self‐fueled micro‐reactor droplets with programmable autonomic behaviors provides a step towards smart liquid dispersions comprising motile microscale objects. Herein, we prepare aqueous suspensions of lipase‐coated oil globules comprising a mixture of a triglyceride substrate (tributyrin, 1,2,3‐tributylglycerol) and a low‐density oil (polydimethylsiloxane, PDMS) and describe a range of active behaviors based on controlled enzyme‐mediated consumption of individual droplets under non‐equilibrium conditions. Encapsulation of the lipase‐coated lipid/PDMS droplets into a model protocell as energy‐rich sub‐compartments is demonstrated as an internalized mechanism for activating protocell buoyancy. Taken together, our results highlight opportunities for the regulation of autonomic behavior in enzyme‐powered oil droplets and provide a new platform for increasing the functionality and energization of synthetic protocells.
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NiFe Hydroxide Lattice Tensile Strain: Enhancement of Adsorption of Oxygenated Intermediates for Efficient Water Oxidation Catalysis
NiFe hydroxide was treated by ball‐milling to enhance its binding strength to an oxygenated intermediate. The prepared NiFe hydroxide that has induced tension shows excellent oxygen evolution performance.
Abstract
The binding strength of reactive intermediates with catalytically active sites plays a crucial role in governing catalytic performance of electrocatalysts. NiFe hydroxide offers efficient oxygen evolution reaction (OER) catalysis in alkaline electrolyte, however weak binding of oxygenated intermediates on NiFe hydroxide still badly limits its catalytic activity. Now, a facile ball‐milling method was developed to enhance binding strength of NiFe hydroxide to oxygenated intermediates via generating tensile strain, which reduced the anti‐bonding filling states in the d orbital and thus facilitated oxygenated intermediates adsorption. The NiFe hydroxide with tensile strain increasing after ball‐milling exhibits an OER onset potential as low as 1.44 V (vs. reversible hydrogen electrode) and requires only a 270 mV overpotential to reach a water oxidation current density of 10 mA cm−2.
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Structure and Reactivity of Al−O(H)−Al Moieties in Siloxide Frameworks: Solution and Gas‐Phase Model Studies
Al‐OH‐Al groups in molecular aluminosiloxides can catalyze olefin isomerizations like solid catalysts and, as for the solids, the reactivity of these sites is blocked by pyridine as a base. Upon deprotonation, the Al3(μ2‐OH)3 core rearranges rendering the acidity of the AlIV‐O(H)‐AlIV units comparable to that of bridging SiIV‐O(H)‐AlIV entities in zeolites. Thus, these units may also contribute significantly to the catalytic activity of zeolites.
Abstract
Even though aluminas and aluminosilicates have found widespread application, a consistent molecular understanding of their surface heterogeneity and the behavior of defects resulting from hydroxylation/dehydroxylation remains unclear. Here, we study the well‐defined molecular model compound, [Al3(μ2‐OH)3(THF)3(PhSi(OSiPh2O)3)2], 1, to gain insight into the acid–base reactivity of cyclic trinuclear Al3(μ2‐OH)3 moieties at the atomic level. We find that, like zeolites, they are sufficiently acidic to catalyze the isomerization of olefins. DFT and gas phase vibrational spectroscopy on solvent‐free and deprotonated 1 show that the six‐membered ring structure of its Al3(μ2‐OH)3 core is unstable with respect to deprotonation of one of its hydroxy groups and rearranges into two edge‐sharing four‐membered rings. This renders AlIV−O(H)−AlIV units strong acid sites, and all results together suggest that their acidity is similar to that of zeolitic SiIV−O(H)−AlIV groups.
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Modular Covalent Graphene Functionalization with C60 and the Endohedral Fullerene Sc3N@C80: A Facile Entry to Synthetic‐Carbon‐Allotrope Hybrids
C C riders: Two graphene–fullerene hybrids containing C60 and endohedral Sc3N@C80 based on pristine graphene rather than popularly used graphene oxide are efficiently constructed using a reductive graphene strategy. The structures of the hybrids are confirmed by a series of spectroscopic and morphological characterizations.
Abstract
Two novel graphene‐fullerene hybrid structures, containing C60 and endohedral Sc3N@C80 bound to graphene, instead of the formerly used graphene oxide, were efficiently synthesized via a reductive activation/exfoliation approach starting from pristine graphite. The structures of these multifunctional hybrid systems were unambiguously characterized by statistical Raman spectroscopy, TG‐MS, TG‐GC‐MS, and LD‐TOF mass spectroscopy, confirming the covalent bonding of the respective C60/Sc3N@C80 moieties to the pristine graphene. Furthermore, assisted by temperature‐dependent Raman spectroscopy studies the corresponding defunctionalization processes were also investigated. Finally, the formation of a carbon allotrope hybrid material on the basis of C60/Sc3N@C80 moieties coupled to graphene could be visualized by HRTEM.
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PPy‐encapsulated SnS2 Nanosheets Stabilized by Defects on TiO2 Support as Durable Anode Material for Lithium‐Ion Battery
PPy‐encapsulated SnS2 nanosheets strongly anchored onto a hydrogen treated TiO2 (H–TiO2) support have been successfully prepared as an anode for LIBs. As demonstrated by first principles, theoretical calculations, and experimental results, the superior binding between SnS2 and the H–TiO2 support via abundant Ti–S bonding, which is reinforced by the oxygen vacancy, contributes to the unprecedented cycle stability.
Abstract
Nanostructured‐alloy‐type anodes have received great interest for high‐performance lithium‐ion batteries (LIBs). However, these anodes experience huge volume fluctuations during repeated lithiation/delithiation and are easily pulverized and subsequently form aggregates. Herein, an efficient method to stabilize alloy‐type anodes by creating defects on the surface of the metal oxide support is proposed. As a demonstration, PPy‐encapsulated SnS2 nanosheets supported on defect‐rich TiO2 nanotubes were produced and investigated as an anode material for LIBs. Both experimental results and theoretical calculations demonstrate that defect‐rich TiO2 provides more chemical adhesions to SnS2 and discharge products, compared to defect‐poor TiO2, and then effectively stabilizes the electrode structure. As a result, the composite exhibits an unprecedented cycle stability. This work paves the way to designing durable and active nanostructured‐alloy‐type anodes on oxide supports.
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Reversible Hydrogen Uptake/Release over a Sodium Phenoxide–Cyclohexanolate Pair
Optimized storage: The metalation of the phenoxide–cyclohexanolate pair is a successful strategy to optimize the thermodynamic properties of this type of hydrogen storage material (see figure). In experiments the sodiated pair desorbed hydrogen at 413 K (373 K) in the solid state (aqueous solution), whereas hydrogenation could be accomplished at temperatures as low as 202 K.
Abstract
Hydrogen uptake and release in arene–cycloalkane pairs provide an attractive opportunity for on‐board and off‐board hydrogen storage. However, the efficiency of arene–cycloalkane pairs currently is limited by unfavorable thermodynamics for hydrogen release. It is shown here that the thermodynamics can be optimized by replacement of H in the ‐OH group of cyclohexanol and phenol with alkali or alkaline earth metals. The enthalpy change upon dehydrogenation decreases substantially, which correlates with the delocalization of the oxygen electron to the benzene ring in phenoxides. Theoretical calculations reveal that replacement of H with a metal leads to a reduction of the HOMO–LUMO energy gap and elongation of the C−H bond in the α site in cyclohexanolate, which indicates that the cyclohexanol is activated upon metal substitution. The experimental results demonstrate that sodium phenoxide–cyclohexanolate, an air‐ and water‐stable pair, can desorb hydrogen at ca. 413 K and 373 K in the solid form and in an aqueous solution, respectively. Hydrogenation, on the other hand, is accomplished at temperatures as low as 303 K.
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Cooperative Chirality and Sequential Energy Transfer in a Supramolecular Light‐Harvesting Nanotube
On the other hand: When two achiral acceptors thioflavin T (ThT) and acridine orange (AO), with different energy bands, were co‐assembled with the nanotube CG it could transfer its chirality to both of the acceptors giving an enhancement of acceptor circularly polarized luminescence (CPL). The excitation energy could be transferred to ThT but only be sequentially transferred to AO.
Abstract
By constructing a supramolecular light‐harvesting chiral nanotube in the aqueous phase, we demonstrate a cooperative energy and chirality transfer. It was found that a cyanostilbene‐appended glutamate compound (CG) self‐assembled into helical nanotubes exhibiting both supramolecular chirality and circularly polarized luminescence (CPL). When two achiral acceptors, ThT and AO, with different energy bands were co‐assembled with the nanotube, the CG nanotube could transfer its chirality to both of the acceptors. The excitation energy could be transferred to ThT but only be sequentially transferred to AO. During this process, the CPL ascribed to the acceptor could be sequentially amplified. This work provides a new insight into the understanding the cooperative chirality and energy transfer in a chiral supramolecular system, which is similar to the natural light‐harvesting antennas.
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From Tolerating Anemia to Treating Anemia
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Long-Term Outcomes Among Patients Discharged From the Hospital With Moderate Anemia A Retrospective Cohort Study
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Nerve Agent Incidents and Public Health Preparedness
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Cost-Effectiveness of Buprenorphine–Naloxone Versus Extended-Release Naltrexone to Prevent Opioid Relapse
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Publication date: 1 May 2019 Source: Talanta, Volume 196 Author(s): Ruiqing Long, Te Li, Chaoying Tong, Lihui Wu, Shuyun Shi Abstract...
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Oral Cancer Rapid Test Kit Market Rugged Expansion Foreseen by 2024 MilTech Oral cancer is one of the largest group of cancers ...
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