The development of three‐dimensional (3D) covalent organic frameworks (COFs) with high chemical stability is of critical importance for their practical uses. In this work, we for the first time demonstrate the stability of 3D COFs can be improved by periodic decoration of isopropyl groups on their backbones. Owing to the strong hydrophobicity of the alkyl groups, the resultant COFs show high crystallinity, permanent pores, and exceptional stability in harsh environments, such as strong acids (3 M...
Mon May 25, 2020 15:24
In recent years, various functionalization strategies for transition metal dichalcogenides have been explored to tailor the materials’ properties and to provide anchor points for the fabrication of hybrid structures. In this report, new insights into the role of the surfactant in functionalization reactions are described. Using the spontaneous reaction of WS 2 with chloroauric acid as a model reaction, the regioselective formation of gold nanoparticles on WS 2 is shown to be heavily dependent...
Mon May 25, 2020 14:34
A coating with “sleeves” : The compact host–guest complexation of calixarene and oleic acid molecules prevents the oxidation of the complex monolayers at the air–water interface by the action of hydroxyl radicals and singlet oxygen. Abstract The oxidation of antioxidants by oxidizers imposes great challenges to both living organisms and the food industry. Here we show that the host–guest complexation of the carefully designed, positively charged, amphiphilic guanidinocalix[5]arene pentadodecyl...
Mon May 25, 2020 14:18
Twist and shout : The integration of plastic twisting and elastic bending in an organic single crystal is achieved. By controlling the twisting degree of the crystal, the polarization direction of light can also be controlled quantitatively and easily. Thus, a new application field of flexible organic single crystals, that is, polarization rotators, is opened up. Abstract Flexible organic single crystals capable of plastic or elastic deformations have a variety of potential applications. Although...
Mon May 25, 2020 14:18
A highly efficient Guerbet‐type reaction at room temperature (catalytic TON up to >6000) is reported. This β‐alkylation of secondary methyl carbinols with primary alcohols delivers higher‐order secondary alcohols in an economical, redox‐neutral fashion. This first enantioselective Guerbet reaction has also been achieved using a commercially available chiral ruthenium complex to deliver secondary alcohols with moderate yield and up to 92 % ee . Abstract We report herein an unprecedented...
Mon May 25, 2020 14:18
Matching the geometry and stacking propensity of linkers allows for tetrathiafulvalene to be replaced with a nickel glyoximate core in a family of metal–organic frameworks with charge transport properties that are in line with their charge density. Abstract The extension of reticular chemistry concepts to electrically conductive three‐dimensional metal–organic frameworks (MOFs) has been challenging, particularly for cases in which strong interactions between electroactive linkers create the...
Mon May 25, 2020 14:17
Breaking B–π conjugation : 9‐Boratriptycene is a bent and non‐conjugated triarylborane with an unprecedented geometrical shape, which confers a low reorganization energy and high Lewis acidity power. Abstract A highly bent triarylborane, 9‐boratriptycene, was generated in solution by selective protodeboronation of the corresponding tetra‐aryl boron ate complex with the strong Brønsted acid HNTf2. The iptycene core confers enhanced Lewis acidity to 9‐boratriptycene, making it unique in terms...
Mon May 25, 2020 14:17
The reductive coupling of a N‐heterocyclic carbene (NHC)‐stabilized (dibromo)vinylborane yields a 1,2‐divinyldiborene, which, although isoelectronic to a 1,3,5‐triene, displays no extended π conjugation due to twisting of the C2B2C2 chain. While this divinyldiborene coordinates to copper(I) and platinum(0) in a η2‐B2 and η4‐C2B2 fashion, respectively, it undergoes a complex rearrangement to a η4‐1,3‐diborete upon complexation with nickel(0).
Mon May 25, 2020 13:35
H2O does a favor : Manganese(I) can achieve a highly efficient and practical hydroarylation of challenging sterically hindered propargyl alcohols despite of the substitution effect under air atmosphere in the presence of water. The precise regioselectivity represents a significant step‐forward towards the hydrofunctionalization of internal alkynes. Abstract We have developed a general and site‐predictable manganese‐catalyzed hydroarylation of internal alkynes in the presence of water, under...
Mon May 25, 2020 13:32
The fabric of memories : A metal fiber with oriented DNA molecules and Ag nanoparticles assembled on the surface as active layer crosses another metal fiber to produce new textile memristor. It shows the best‐in‐class performances, with an ultra‐low operation voltage of 0.3 V and power consumption of 100 pW and ultra‐high switching speed of 20 ns, which exceed previous organic memristors. Abstract Electronic textiles may revolutionize many fields, such as communication, health care and artificial...
Mon May 25, 2020 13:31
3D chiral gold NPs were synthesized using dipeptide γ‐glutamylcysteine (γ‐Glu‐Cys) and cysteinylglycine (Cys‐Gly) structure‐directing agents. Crystallographic analysis of the γ‐Glu‐Cys‐directed NPs reveal a cube‐like outline with a protruding chiral wing, whereas NPs synthesized with Cys‐Gly—so‐called 432 helicoid V—exhibit a rhombic dodecahedron‐like outline with curved edges and elliptical cavities on each face. Abstract Chiral optical metamaterials with delicate structures are in high demand...
Mon May 25, 2020 13:28
(3+2) is more than 5 ! This Review presents milestones of the Huisgen reaction, also known as the 1,3‐dipolar cycloaddition. The historical development, mechanistic aspects, and computational investigations as well as applications in the synthesis of heterocycles, natural products, and biologically active compounds, biosynthesis, and in click chemistry are discussed. Abstract The concept of 1,3‐dipolar cycloadditions was presented by Rolf Huisgen 60 years ago. Previously unknown reactive intermediates,...
Mon May 25, 2020 13:27
It's a two‐way street : Using an array of gate electrodes at the base of a microfluidic chamber, electroosmotically driven bidirectional flow, a set of adjacent flow strips with alternating flow direction and tunable velocity magnitude, was created. It is shown that high‐diffusivity species introduced into the flow experience a net‐zero velocity, while lower diffusivity species are continuously advected and thus separated. Abstract We present a new concept for on‐chip separation that leverages...
Mon May 25, 2020 13:27
A systematic QM/MM study for predicting 19F NMR chemical shifts of a fluorinated inhibitor covalently bound to the essential oxidoreductase tryparedoxin from Trypanosoma brucei is reported. Sampling over protein–inhibitor conformations of monomeric and dimeric inhibitor–protein complexes enables the prediction of the inhibitor binding mode. This is currently the largest computational study on 19F chemical shifts in a biological context. Abstract The absence of fluorine from most biomolecules...
Mon May 25, 2020 13:27
Asymmetric total synthesis of five kopsane alkaloids containing a heptacyclic caged ring system was accomplished. The total synthesis hinges on a PtCl2‐catalyzed intramolecular [3+2] cycloaddition, which promotes assembly of pentacyclic carbon skeletons bearing 2,3‐quaternary functionalized indoline scaffolds with excellent control of diastereoselectivity. Abstract A concise and asymmetric total synthesis of five kopsane alkaloids that share a unique heptacyclic caged ring system was accomplished....
Mon May 25, 2020 13:26
Up the hill : The ion transport through molecular‐size channels of porphyrin‐based metal–organic framework membrane could be modulated with light in a relatively precise manner. Thanks to the molecular‐scale pore size, the modulation is stable at a broad ion concentration range. After decoration with Pt nanoparticles to form a Schottky barrier photodiode, the membrane can drive “uphill” ion transport through the application of light. Abstract Biological ion channels and ion pumps with sub‐nanometer...
Mon May 25, 2020 13:26
One mutant, six targets : The regio‐ and stereoselective C−H activation for hydroxylation of six different steroids with formation of C7β alcohols was accomplished using a single P450 mutant evolved by protein library construction based on a special DNA assembly and cloning procedure. The C7β steroidal alcohols, not readily accessible by synthetic reagents or catalysts, are of intense interest as therapeutic drugs. Abstract Steroidal C7β alcohols and their respective esters have shown significant...
Mon May 25, 2020 13:26
Kinetically controlled DNA nanostructures were generated through purely chemical reactions. In their Research Article (DOI: https://doi.org/10.1002/anie.20200218010.1002/anie.202002180), F. Ricci and co‐workers demonstrate transient self‐assembly of DNA‐based nanostructures achieved by reduction/oxidation of disulfide/thiol controllers. Inspired by redox signaling in cells to control cellular processes, redox cycles of DNA‐based disulfide controller strands were employed to kinetically control the...
Mon May 25, 2020 13:26
IDM‐1: A Zeolite with Intersecting Medium and Extra‐Large Pores Built as an Expansion of Zeolite MFI
IDM‐1, a highly stable silica zeolite , was constructed as a structural expansion of zeolite ZSM‐5 by alternating pentasil layers and interrupted layers, thus giving rise to an intersecting system of straight medium pores and undulating extra‐large lobed pores. The synthesis is directed by a diquat resembling two rigidly joined tetrapropylammonium cations. Abstract IDM‐1 is a new silica zeolite with an ordered and well‐defined framework constructed by alternating pentasil layers and interrupted...
Mon May 25, 2020 13:23
Carbon‐supported NiII single‐atom catalysts possessing a tetradentate Ni‐N2O2 coordination were synthesized by a simple Schiff base ligand‐mediated pyrolysis strategy. It could electrocatalytically reduce O2 in air to H2O2 at a high current density with a high H2O2 selectivity using a three‐phase flow cell. A precise Ni‐N2O2 coordination was key to this impressive performance. Abstract Carbon‐supported NiII single‐atom catalysts with a tetradentate Ni‐N2O2 coordination formed by a Schiff base...
Mon May 25, 2020 13:22
Iron supplements : Deposition of Fe(OH)x on Pt nanoparticles created FeIII‐OH‐Pt interfaces, which combine the facile dissociation of H2 on Pt with the hydrodeoxygenation process of the Fe3+/Fe2+ redox cycle, thus facilitating the chemoselective hydrogenation of a broad range of substituted nitrobenzenes to the corresponding anilines without hydrogenating other substituents. Abstract Catalytic hydrogenation of nitroaromatics is an environment‐benign strategy to produce industrially important...
Mon May 25, 2020 13:22
“Aggregation‐induced emission research has brought us to the meso territory, where the synergy and cooperation between many molecules in the aggregate make it different from its elementary components. … Let's enthusiastically embrace the opportunity to develop meso science and to innovate meso technology, and make our planet a brighter place to live !” Read more in the Guest Editorial by B. Liu and B. Z. Tang.
Mon May 25, 2020 13:22
Ground control : Self‐assembly of achiral AIEgens (AIE=aggregation induced emission) and chiral donors with metal ions into metal—organic frameworks (MOFs) enabled solid‐state emission and through‐space chirality transfer. The fluorescence/circularly polarized luminescence (CPL) MOFs have a reversible, dual‐mode mechano‐response through grinding and ultrasound. Abstract Circularly polarized luminescence (CPL) is attractive in understanding the excited‐state chirality and developing advanced...
Mon May 25, 2020 13:21
Boracycles π‐captured : The first actinide‐based molecules featuring π‐ligated neutral diborabenzene (dbb) as sandwich‐type ligand are reported. Experimental and theoretical studies suggest that the unique strength of the actinide–dbb bond is mainly electrostatic in nature with distinct covalent ligand‐to‐metal orbital contributions. Abstract The π coordination of arene and anionic heteroarene ligands is a ubiquitous bonding motif in the organometallic chemistry of d‐block and f‐block elements....
Mon May 25, 2020 13:20
Lithium salt added to the electrolyte of a calcium‐metal battery reduces the oxygen coordination number for the 43Ca nucleus in the first solvation shell, thereby promoting the desolvation kinetics of Ca2+ ions and the cycling performance of the calcium‐metal anode. Excellent reversibility of calcium plating and stripping is realized. Abstract Calcium‐metal batteries (CMBs) provide a promising option for high‐energy and cost‐effective energy‐storage technology beyond the current state‐of‐the‐art...
Mon May 25, 2020 13:18
“The secret of being a successful scientist is to do your own and labeled research … In my first experiment I unintentionally functionalized carbon nanotubes, on which Pt nanoparticles were deposited uniformly. Luck is part of research …” Find out more about Shuangyin Wang in his Author Profile.
Mon May 25, 2020 13:18
Trivalent lanthanides complexes possess strong magnetic anisotropy and are efficient single‐molecule magnets (SMMs). The ab initio calculations of monoxides of terbium (Tb), dysprosium (Dy), and holmium (Ho) proved that divalent lanthanide complexes can also be efficient SMMs with very high magnetization blocking barriers. When adsorbed on hexagonal boron nitride, DyO preserved its anisotropic properties and exhibited a magnetization blocking barrier >3000 K. Abstract Complexes of trivalent...
Mon May 25, 2020 13:17
Copolymerization of pyrrole and tellurophene by a microemulsion method led to a facile synthesis in situ of a series of copolymeric nanoparticles. Photothermal/photodynamic effects were precisely and systematically tuned by simply adjusting the ratio of tellurophene/pyrrole, providing a therapeutic nanoplatform that can heal cancer under normoxic and hypoxic conditions. Abstract Cancer possesses normoxic and hypoxia microenvironments with different levels of oxygen, needing different efficacies...
Mon May 25, 2020 13:14
Taking the lead : The highly dynamic secondary TAR RNA structure of HIV‐1 is used to template cycloaddition reactions leading to the generation of triazole‐containing thiazole peptidomimetics as selective leads. The triazole ligand with flexible methylene units selectively binds to TAR RNA over TAR RNA without a bulge and TAR DNA. The ligand presumably binds in the bulge region of the TAR RNA and inhibits its interaction with the Tat peptide. Abstract The highly conserved HIV‐1 transactivation...
Mon May 25, 2020 13:14
Hematite‐based mesocrystals assembled from highly oriented tiny nanoparticle subunits achieve superior photoelectrochemical water splitting performance under solar irradiation. In their Research Article on https://doi.org/10.1002/anie.201914728page 9047, T. Tachikawa and co‐workers show how rich interfacial oxygen vacancies yield an exceedingly high carrier density and a large proportion of ultra‐narrow depletion layers (<1 nm) inside the mesoporous film, thus boosting multihole water oxidation...
Mon May 25, 2020 12:39
Experimental isolation of FRMs from the papillary and reticular dermis of adult buttock skin was performed by cryosectioning bisected 6 mm skin biopsies en face. Atomic force microscopy images of FRM isolated from human papillary and reticular dermis reveal the “beads‐on‐a‐string” morphology. In the reticular dermis there was no significant difference in FRM ultrastructure between European and African participants. In contrast, in the more superficial papillary dermis, inter‐bead periodicity was...
Mon May 25, 2020 20:36
Publication date: August 2020Source: Journal of Human Evolution, Volume 145Author(s): René Bobe, David R. Braun, Anna K. Behrensmeyer, John W.K. Harris
Tue May 26, 2020 12:39
Publication date: July 2020Source: Journal of Human Evolution, Volume 144Author(s): Rachna B. Reddy, John C. Mitani
Tue May 26, 2020 12:39
Publication date: 1 October 2020Source: Talanta, Volume 218Author(s): Fangbin Fan, Licheng Wang, Yijing Li, Xusheng Wang, Xiaofeng Lu, Yong Guo
Tue May 26, 2020 12:32
Growth hormone deficiency (GHD) in children has significant impacts on growth and metabolism. Two-agent GH stimulation tests are commonly used to diagnose GHD, and these tests are generally considered safe. We report the case of a 5-year 5-month-old boy with a history of anaplastic ependymoma who underwent GH stimulation testing for growth deceleration using clonidine and arginine. He developed bilateral calf myalgia and gross hematuria within 24 hours of the tests. Myalgia and hematuria resolved...
Tue May 26, 2020 10:05
Breast metastasis from thyroid papillary carcinoma is an exceptional situation. Here, we present the diagnostic approach and the management of a 19-year-old woman with single breast metastasis from thyroid carcinoma. There was no extra thyroidal extension, neoplastic emboli, or lymph node invasion. The metastasis was revealed by whole-body radioactive 131I scan, explored by a fine-needle aspiration, and confirmed by elevated thyroglobulin in situ. Received for publication December 9, 2019; revision...
Wed May 20, 2020 03:00
A 52-year-old woman with no medical history was admitted on March 18, 2020, presenting since 3 days asthenia, abdominal pain, and dry cough but no fever. Adenomegalies, splenomegaly, leukocytosis, and elevated LDH suggested mature lymphoproliferation. Considering the current health context, an RT-PCR testing for COVID-19 (coronavirus disease 2019) was performed and found to be positive. Early chest CT showed no sign of pulmonary infection but multiple adenomegalies. An 18F-FDG PET/CT performed 5...
Wed May 20, 2020 03:00
We present the first intraoperative detection of a hyperplastic parathyroid gland with a positron emitter 18F-fluorocholine and handheld probe, with the estimation of the absorbed dose to the surgeon and surgical staff. Intraoperative positron emitter detection enabled the resection of a small parathyroid gland, resulting in normal postoperative values of PTH and serum calcium in a 69-year-old woman. Calculated whole-body dose to the surgical staff and surgeons’ fingers is well below the annual limits...
Wed May 20, 2020 03:00
A 75-year-old man with a history of prostate cancer (T1N0M0, Gleason score 4 + 3) was referred to radionuclide bone scan and 68Ga-PSMA PET/CT to detect recurrence. Multiple abnormal foci were observed in the axial and appendicular skeleton, which were suggestive of metastatic superscan from prostate cancer. However, histopathological examinations (from bone biopsy) did not support the metastases from prostate cancer. 68Ga-FAPI PET/CT was then performed to detect the occult tumor, which showed intense...
Wed May 20, 2020 03:00
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Medicine by Alexandros G. Sfakianakis,Anapafseos 5 Agios Nikolaos 72100 Crete Greece,00302841026182,00306932607174,alsfakia@gmail.com,