bluuebunny/crossref_metadata_2025 huggingface dataset:
Autonomous Self‐Healing Elastomers with Unprecedented Adhesion Force
Authors: Zhang Zhen , Ghezawi Natasha , Li Bingrui , Ge Sirui , Zhao Sheng , Saito Tomonori , Hun Diana , Cao Peng‐Fei
Published: October 2020

Self‐healable elastomers are extremely attractive due to their ability to prolong product lifetime. An additional function that could further expand their applications is strong adhesion force to clean and dusty surfaces. This study reports a series of autonomous self‐healable and highly adhesive elastomers (ASHA‐Elastomer) that are fabricated via a simple, efficient, and scalable process. The obtained elastomers exhibit outstanding mechanical properties with elongation at break up to 2102% and toughness (modulus of toughness) of 1.73 MJ m–3. The damaged ASHA‐Elastomer can autonomously self‐heal with full recovery of functionalities, and the healing process is not affected by the presence of water. The elastomers are found to possess an ultrahigh adhesion force up to 3488 N m−1, greatly outperforming previously reported self‐healing adhesive elastomers. Furthermore, the adhesion force of the ASHA‐Elastomer is negligibly affected by dust on the surface, in stark contrast with regular adhesive polymers that have adhesion strengths extremely sensitive to dust. The successful development of high‐toughness, autonomous self‐healable, and ultra‐adhesive elastomers will enable a wide range of applications with enhanced longevity and versatility, including their use in sealants, adhesives, and stretchable devices.
Tumor‐Targeting Glycol Chitosan Nanoparticles for Cancer Heterogeneity
Authors: Ryu Ju Hee , Yoon Hong Yeol , Sun In‐Cheol , Kwon Ick Chan , Kim Kwangmeyung
Published: October 2020

Nanomedicine is extensively employed for cancer treatment owing to its unique advantages over conventional drugs and imaging agents. This increased attention to nanomedicine, however, has not fully translated into clinical utilization and patient benefits due to issues associated with reticuloendothelial system clearance, tumor heterogeneity, and complexity of the tumor microenvironment. To address these challenges, efforts are being made to modify the design of nanomedicines, including optimization of their physiochemical properties, active targeting, and response to stimuli, but these studies are often performed independently. Combining favorable nanomedicine designs from individual studies may improve therapeutic outcomes, but, this is difficult to achieve as the effects of different designs are interconnected and often conflicting. Glycol chitosan nanoparticles (CNPs) are shown to accumulate in tumors, suggesting that this type of nanoparticle may constitute a good basis for the additional modification of nanoparticles. Here, multifunctional glycol CNPs designed to overcome multiple obstacles to their use are described and key factors influencing in vivo targeted delivery, targeting strategies, and interesting stimulus‐responsive designs for improving cancer nanomedicine are discussed.
Thickness‐Dependent, Gate‐Tunable Rectification and Highly Sensitive Photovoltaic Behavior of Heterostructured GeSe/WS2 p–n Diode
Authors: Jaffery Syed Hassan Abbas , Kim Junghwan , Dastgeer Ghulam , Hussain Muhammad , Ali Asif , Hussain Sajjad , Eom Jonghwa , Hong Suklyun , Jung Jongwan
Published: October 2020

The p–n heterojunction fabricated by the vertical stacking of 2D materials is highly relevant to modern electronics and optoelectronic devices. This research reports a novel p‐GeSe/n‐WS2 heterostructured diode exhibiting prominent thickness‐dependent and gate‐tunable rectification behavior. The rectification ratio increases as the thickness of WS2 is increased. A rectification ratio of 104 is achieved by successfully sweeping the back‐gate voltage. The modulation in the rectification behavior is ascribed to the interlayer electron‐hole recombination. Density functional theory (DFT) calculations further support the thickness‐dependent, gate‐modulated experimental results. The diode exhibits efficient photodetection with promising figures of merit. The photoresponse is investigated under the illuminations of λ equal to 365, 530, and 850 nm. The diode displays a high responsivity of 845 mA W−1 at 850 nm. In addition, the diode exhibits a detectivity of 3.28 × 108 Jones, normalized photocurrent to dark current ratio (NPDR) of 1 × 108 W−1, noise equivalent power (NEP) of 1.9 × 10−12 WHz−1/2, and a rise time of 10 ms. The p‐GeSe/n‐WS2 diode demonstrates excellent rectification and optoelectronic characteristics.
Sub‐10 nm Distance Measurements between Fluorophores using Photon‐Accumulation Enhanced Reconstruction
Authors: Dong Biqin , Song Ki-Hee , Davis Janel L. , Zhang Hao F. , Sun Cheng
Published: October 2020

Single‐molecule localization microscopy (SMLM) precisely localizes individual fluorescent molecules within the wide field of view (FOV). However, the localization precision is fundamentally limited to around 20 nm due to the physical photon limit of individual stochastic single‐molecule emissions. Using spectroscopic SMLM (sSMLM) to resolve their distinct fluorescence emission spectra, individual fluorophore is specifically distinguished and identified, even the ones of the same type. Consequently, the reported photon‐accumulation enhanced reconstruction (PACER) method accumulates photons over repeated stochastic emissions from the same fluorophore to significantly improve the localization precision. This work shows the feasibility of PACER by resolving quantum dots that are 6.1 nm apart with 1.7 nm localization precision. Next, a Monte Carlo simulation is used to investigate the success probability of the PACER's classification process for distance measurements under different conditions. Finally, PACER is used to resolve and measure the lengths of DNA origami nanorulers with an inter‐molecular spacing as small as 6 nm. Notably, the demonstrated sub‐2 nm localization precision bridges the detection range between Förster resonance energy transfer (FRET) and conventional SMLM. Fully exploiting the underlying imaging capability can potentially enable high‐throughput inter‐molecular distance measurements over a large FOV.
Construction and Humidity Response of a Room‐Temperature‐Phosphorescent Hybrid Xerogel Based on a Multicharge Supramolecular Assembly
Authors: Fan Wen-Tao , Chen Yong , Niu Jie , Su Ting , Li Jing-Jing , Liu Yu
Published: October 2020

Organic room‐temperature phosphorescence (RTP) has attracted tremendous attention in recent years due to its potential utility in combination with artificial soft materials. Herein, a room‐temperature‐phosphorescent hybrid xerogel held together by electrostatic and host–guest interactions is reported. The xerogel is constructed by noncovalent complexation of 7‐[6‐deoxy‐6‐(2‐sulfonic)]‐β‐cyclodextrin (SCD) with the phosphor bromophenyl‐methyl‐pyridinium chloride (PYCl) and in situ incorporation of the anionic SCD⊃PYCl complex into a cationic amino clay (AC) via electrostatic interactions. The resulting xerogel, designated AC/SCD⊃PYCl, has a network structure that can suppress vibrational and nonradiative relaxation of the phosphor, leading to green RTP emission as well as good fluorescence–phosphorescence dual emission. Notably, the intensity of the xerogel RTP varies with humidity and can be switched on and off repeatedly, which indicates that the xerogel has potential utility as an organic light‐emitting humidity‐sensing material.
Price transmission with sparse market information: The case of United States chickpeas
Authors: Hatzenbuehler Patrick L. , Du Xiaoxue , Painter Kathleen
Published: October 2020

In this paper, supply‐related and price data for several chickpea importing regions and supply‐related data for export competitor countries were encompassed into price transmission models to determine whether such factors are helpful for explaining the United States chickpea price variation. Specifically, the models included satellite‐based normalized difference vegetation index, a measure of growing conditions, and area planted estimates for importing regions of the Indian subcontinent and the Mediterranean, and area planted estimates for exporting competitors, Australia and Canada. Results show that inclusion of supply‐related information improved goodness of fit statistics in all models relative to base models that only include prices, providing evidence that such information is important for explaining United States chickpea price changes. The models with the highest goodness of fit statistics were those that accounted for (1) deteriorating growing conditions in the Mediterranean region coinciding with declining area planted in Canada and (2) concurrently deteriorating growing conditions and declining area planted in the Indian subcontinent. [EconLit citations: Q11, Q17]
Solitary chemosensory cells are innervated by trigeminal nerve endings and autoregulated by cholinergic receptors
Authors: Deng Jie , Tan Li Hui , Kohanski Michael A. , Kennedy David W. , Bosso John V. , Adappa Nithin D. , Palmer James N. , Shi Jianbo , Cohen Noam A.
Published: October 2020

Background

Solitary chemosensory cells (SCCs) in the murine nasal epithelium are discrete specialized cells that respond to irritants and activate trigeminal nerve fibers through the release of acetylcholine (ACh), resulting in local neurogenic inflammation. In addition to releasing ACh, SCCs are the exclusive epithelial source of interleukin (IL)‐25. In humans, SCCs are significantly expanded in sinonasal polyps (NPs). However, the SCC‐trigeminal synapse has yet to be demonstrated in human sinonasal epithelium.

Methods

Immunofluorescence for trigeminal nerve fiber markers, nicotinic ACh receptors (nChR), and SCC markers was performed in vibratome sections from polyp and healthy turbinate tissue. Quantitative polymerase chain reaction and immunofluorescence of cultured epithelial cells were used to evaluate the expansion of SCCs. Last, intracellular calcium imaging was used to demonstrate cholinergic signaling in sinonasal epithelial cells.

Results

Calcitonin gene‒related peptide (CGRP) immunostaining was used to identify cholinergic nerve endings, which were only evident in sections from the inferior turbinate and intertwined with SCCs (α‐gustducin‒positive cells). CGRP‐positive nerve endings were not identified in sections from NPs. Human SCCs expressed nChR as well as the ACh synthetic enzyme choline acetyltransferase. Live cell calcium imaging demonstrated functionally active cholinergic signaling in discrete sinonasal epithelial cells, consistent with SCCs. Finally, SCC‐specific genes were dramatically upregulated with pretreatment with IL‐13 and nicotinic agonists.

Conclusion

SCCs are innervated by trigeminal nerve endings in healthy turbinate tissue but not in NPs. SCCs express ACh receptors as well as choline acetyltransferase and, in the setting of a type 2 inflammatory environment, denervated SCCs dramatically expand with nicotinic stimulation.
Exploring the Organometallic Route to Molecular Spin Qubits: The [CpTi(cot)] Case
Authors: de Camargo Luana C. , Briganti Matteo , Santana Francielli S. , Stinghen Danilo , Ribeiro Ronny R. , Nunes Giovana G. , Soares Jaísa F. , Salvadori Enrico , Chiesa Mario , Benci Stefano , Torre Renato , Sorace Lorenzo , Totti Federico , Sessoli Roberta
Published: October 2020

The coherence time of the 17‐electron, mixed sandwich complex [CpTi(cot)], (η8‐cyclooctatetraene)(η5‐cyclopentadienyl)titanium, reaches 34 μs at 4.5 K in a frozen deuterated toluene solution. This is a remarkable coherence time for a highly protonated molecule. The intramolecular distances between the Ti and H atoms provide a good compromise between instantaneous and spin diffusion sources of decoherence. Ab initio calculations at the molecular and crystal packing levels reveal that the characteristic low‐energy ring rotations of the sandwich framework do not yield a too detrimental spin‐lattice relaxation because of their small spin–phonon coupling. The volatility of [CpTi(cot)] and the accessibility of the semi‐occupied, non‐bonding d
orbital make this neutral compound an ideal candidate for single‐qubit addressing on surface and quantum sensing in combination with scanning probe microscopy.
CoNi Alloy Nanoparticles Embedded in Metal–Organic Framework‐Derived Carbon for the Highly Efficient Separation of Xenon and Krypton via a Charge‐Transfer Effect
Authors: Chen Fuqiang , Ding Jiaqi , Guo Kaiqing , Yang Liu , Zhang Zhiguo , Yang Qiwei , Yang Yiwen , Bao Zongbi , He Yi , Ren Qilong
Published: October 2020

Separation of Xe and Kr is one of the greatest challenges in the gas industries owing to their close molecular structure and similar properties. Energy‐effective adsorption‐based separation using chemically stable carbon adsorbents is a promising technology. We propose a strategy for Xe/Kr separation using MOF‐derived metallic carbon adsorbents. M‐Gallate (M=Ni, Co) were used as precursors to fabricate CoNi alloy nanoparticles embedded carbon adsorbents by one‐step auto‐reduction pyrolysis. The optimal NiCo@C‐700 exhibits record‐high IAST selectivity (24.1) and Henry's selectivity (20.1) of Xe/Kr among reported carbon adsorbents. DFT calculations, local density of states calculation, charge density difference, and Bader charge analysis reveal the great affinity with Xe benefits from the presence of Ni or CoNi nanoparticles as a result of more charge transfer from Xe than Kr to metal, thus providing higher binding energy. Breakthrough experiments further verify NiCo@C‐700 a promising candidate for Xe/Kr separation.
Palladium‐Catalyzed Regio‐, Diastereo‐, and Enantioselective 1,2‐Arylfluorination of Internal Enamides
Authors: Xi Yang , Wang Chenchen , Zhang Qian , Qu Jingping , Chen Yifeng
Published: October 2020

We herein describe a palladium‐catalyzed three‐component coupling of internal enamides, arylboronic acids, and Selectfluor to access the chiral β‐fluoroaminated moiety with up to 99 % ee. The prefunctionalized oxazolidinone substituted alkene enables the expedient construction of two vicinal stereocenters with excellent regio‐, diastereo‐, and enantioselectivities. The synthetic application is exhibited by selective transformation of the product into various vicinal benzylic fluoride derivatives.
Mild C–C Bond Formation via Lewis Acid Catalyzed Oxetane Ring Opening with Soft Carbon Nucleophiles
Authors: Huang Hai , Zhang Tianyu , Sun Jianwei
Published: October 2020

Mild oxetane opening by soft carbon nucleophiles has been developed for efficient C−C bond formation. In the presence of LiNTf2 or TBSNTf2 as catalyst, silyl ketene acetals were found to be effective nucleophiles to generate a wide range of highly oxygenated molecules, which are key substructure in natural products like polyketides. Furthermore, intramolecular oxetane opening by a styrene‐based carbon nucleophile via a Prins‐type process was also achieved with Sc(OTf)3 as catalyst, leading to efficient formation of the useful 2,3‐dihydrobenzo[b]oxepine skeleton.
Boranyl‐Functionalized [Ge9] Clusters: Providing the Idea of Intramolecular Ge/B Frustrated Lewis Pairs
Authors: Wallach Christoph , Geitner Felix S. , Karttunen Antti J. , Fässler Thomas F.
Published: October 2020

The unique three‐dimensional structure of spherical, homoatomic nine‐atom germanium clusters opens various possibilities for the spatial arrangement of functional groups. Ligands comprising lone pairs have recently been introduced in the cluster sphere, and we now report the addition of a boranyl group to the cluster featuring a Ge−B exo‐cluster bond. The reaction of the twofold‐silylated cluster [Ge9{Si(TMS)3}2]2− (TMS=trimethylsilyl) with 2‐chloro‐1,3,2‐diazaborolidines DABR‐Cl leads to the first boranyl‐functionalized [Ge9] clusters [Ge9{Si(TMS)3}2DABR]− (R=methyl (1 a), iso‐propyl (2 a), ortho‐tolyl (3 a)). The anions 2 a and 3 a were structurally characterized as [NHCDippCu]+ complexes (NHCDipp=1,3‐di(2,6‐diisopropylphenyl)imidazolylidine) through single crystal X‐ray structure determination. Quantum‐chemical calculations manifest the frustrated Lewis pair (FLP) character of the boranyl‐functionalized cluster [Ge9{Si(TMS)3}2BCy2]− (4 a).
Iron‐Catalyzed Regioselective Alkenylboration of Olefins
Authors: Yu Xiaolong , Zheng Hongling , Zhao Haonan , Lee Boon Chong , Koh Ming Joo
Published: October 2020

The first examples of an iron‐catalyzed three‐component synthesis of homoallylic boronates from regioselective union of bis(pinacolato)diboron, an alkenyl halide (bromide, chloride or fluoride), and an olefin are disclosed. Products that bear tertiary or quaternary carbon centers could be generated in up to 87 % yield as single regioisomers with complete retention of the olefin stereochemistry. With cyclopropylidene‐containing substrates, ring cleavage leading to trisubstituted E‐alkenylboronates were selectively obtained. Mechanistic studies revealed reaction attributes that are distinct from previously reported alkene carboboration pathways.
A practical model of the diffusion of oil‐based fluid into polyethylene
Authors: Zaribaf Fedra P. , Hassuji Tahir A. , Cookson Andrew N. , Gill Harinderjit S. , Pegg Elise C.
Published: October 2020

It is possible to modify the properties of semicrystalline polymers using diffusion to introduce additional functionality. For example, Vitamin E infused polyethylene has antioxidant properties, which enhances the longevity of the polyethylene. Lipiodol ultra fluid, an iodinated oil‐based contrast agent, can be used to enhance the X‐ray attenuation of medical grade polyethylene. To manufacture a part geometry with a sufficiently even distribution of oil for radiopacity, while maintaining the thermally dependent properties of the polymer (e.g., crystallinity) is a challenge. Rather than relying on trial and error, this study aimed to identify the simplest, most practical model, which could assist with planning for manufacturing of such parts. Models in 1D, 2D, and 3D were examined but only the 3D Fickian model was able to predict the profile of oil diffusion within polyethylene with suitable performance (as low as 7% inaccuracy for some diffusion conditions). The model was more accurate at the surface of the samples and at lower diffusion temperatures. The 3D Fickian model used in this study was capable of estimating the oil concentration in the surface of a polyethylene part after diffusion to a sufficient accuracy for planning manufacturing processes of oil‐infused polyethylene parts.
Comparative analysis of the processes of collagen concentration by ultrafiltration using different types of membranes
Authors: Batrinescu Gheorghe , Scutariu Roxana‐Elena , Nechifor Gheorghe , Ionescu Ioana‐Alexandra , Iancu Vasile‐Ion
Published: October 2020

Tangential flow filtration of the collagen protein solutions with a molecular weight 12, 14, and 24 kDa is investigated using flat sheet membranes. The effects of tangential ultrafiltration (UF) on the permeate properties using two regenerated celluloses (RCs) and two polyethersulfone (PES) membranes with molecular weight cut‐off (MWCO) of 5 and 10 kDa are reported. The permeate and concentrate obtained in the UF experiments are characterized from a physical–chemical point of view by determining the temperature, pH, electrical conductivity, nitrogen content, and protein concentration. In addition, the experimental data are modeled using Hermia's model. The UF experiments demonstrated that permeate flux declined with increasing molecular weight of collagen at constant concentration (1%). Regardless of the molecular weight of collagen, the rejections decrease in the following order: PES 5 kDa > RC5kDa > RC10kDa > PES10kDa. In case of membrane with higher MWCO, the clogging phenomenon is mainly due to the blockage of the internal pores of the membrane than the formation of a polarization layer. Morphologies and characteristics of the membranes are characterized using scanning electron microscopy.
Reducing the crystallinity of high molecular weight poly (ethylene oxide) using ultraviolet cross‐linking for preparation of gas separation membranes
Authors: Motahari Fereshteh , Raisi Ahmadreza
Published: October 2020

CO2‐selective cross‐linked poly (ethylene oxide) (PEO) membranes were prepared by the UV irradiation of high molecular weight PEO in the presence of benzophenone as photo‐initiator, which act as a hydrogen‐abstracting agent. The main goal was to study the effects of the cross‐linking process on the structural properties of hydrogel films intended for the gas separation applications. It was found that the gel fraction, and cross‐link density enhanced, and the crystallinity, and the size of spherulites decreased by the cross‐linking process. Moreover, the permeation performances for N2, O2, CH4, and CO2and the relationship between the gas permeation performances and physical properties were investigated. The results indicated that the degree of cross‐linking and crystallinity could be controlled by changing the initiator concentration, as by increasing the initiator content, the crystallinity percent and gas permeability of the membranes decreased, and the gas pair ideal selectivity of CO2/N2, CO2/CH4, CH4/N2, and O2/N2increased.
Microcrack surface density in the human otic capsule: An unbiased stereological quantification
Authors: Hansen Lars Juul , Bloch Sune Land , Frisch Thomas , Sørensen Mads Sølvsten
Published: October 2020

Bone is continuously remodeled to repair and strengthen degenerative bone with accumulating dead osteocytes and microfractures. Inner ear osteoprotegerin (OPG)‐mediated inhibition of otic capsular bone remodeling causes excessive perilabyrinthine bone degeneration. Consequently, microcracks accumulate around the inner ear. Microcracks cause osteocyte apoptosis and may disrupt the canalicular network connecting osteocytes. Despite their linear microscopic appearance, microcracks are three‐dimensional disruption planes and represent surface areas inside a tissue space. With an elevated microcrack burden the number of disconnected osteocytes is expected to increase. This may prove relevant to ongoing research in otic focal pathologies like otosclerosis. Therefore, an unbiased quantification of the microcrack surface density (mm2/mm3) in the human otic capsule is essential. In this study unbiased stereology was applied to undecalcified bulk stained human temporal bones to demonstrate its feasibility in describing the three‐dimensional reality behind two dimensional observations of microcracks. A total of 28 human temporal bones and five ribs were bulk stained in basic fuchsin, serially sectioned and hand‐ground to a thickness of 80–120 μm. Both horizontal and vertical sections were produced and compared. This study showed that surface density of microcracks was significantly higher around the inner ear compared to ribs. Furthermore, no significant difference in microcrack surface density between horizontal and vertical sections in the temporal bone was demonstrated.
Reflective Writing on the Cadaveric Dissection Experience: An Effective Tool to Assess the Impact of Dissection on Learning of Anatomy, Humanism, Empathy, Well‐Being, and Professional Identity Formation in Medical Students
Authors: Abrams Matthew P. , Eckert Tabitha , Topping Daniel , Daly Katherine D.
Published: October 2020

Growing evidence supports the use of reflective writing activities centered around the human cadaveric dissection experience to support and assess elements of medical student wellness. Dissection may promote personal and professional development, increase resilience, and foster a sense of connection and community. This study employed a qualitative analysis of a reflective writing exercise to explore the question: “What is the impact of the cadaveric dissection anatomy experience on the personal and professional development of medical students?” This cross‐sectional study was conducted at the conclusion of the first‐year anatomy module. A total of 117 United States allopathic medical students were given a questionnaire designed to elicit the students' experiences and introspection. The exercise included four reflective questions that were provided to 20 groups of six students. Grounded theory analysis was used to explore themes that arose in students' responses. Participants exhibited several common reactions to cadaveric dissection. After analyzing all responses, 266 unique open codes were identified for all four questions. These open codes were sorted into ten distinct axial codes, which are broader categorical themes of open codes. The aims of our study were to identify themes that emerged as students reflected on the impact of their dissection experience using reflective writing as a tool to capture these themes and to gather information to inform pedagogical methodologies. The researchers observed that the educational effects of dissection captured in the reflective writing resembled those found in other areas of medical education that emphasize professional identity formation and important humanistic qualities.
Defect Engineering of van der Waals Solids for Electrocatalytic Hydrogen Evolution
Authors: Yang Leping , Yang Xiaohan , Yu Lingxiao , Lv Ruitao
Published: October 2020

Van der Waals solids with tunable band gaps and interfacial properties have been regarded as a class of promising active materials for electrocatalytic hydrogen evolution reaction (HER). However, due to the anisotropic features, their basal planes are usually electrochemically inert, only a few unsaturated edge atoms could serve as active centers to actuate H2 generation. Hence, material utilization and productivity efficiency are insufficient for practical applications. Recently, diverse defects have been confirmed to enable tailoring atomic configurations and electronic properties of van der Waals solids, thus triggering their superior catalytic activity of in‐plane atoms while introducing high amount of new active sites. In this minireview, we summarize the state‐of‐the‐art progress of defect engineering in van der Waals solids for HER, focusing in particular on their advantages in material modification and corresponding catalytic mechanisms. We also propose the challenges and perspectives of these catalytic materials in terms of both experimental synthesis and fundamental understanding of the defect structures.
Solvent‐free liquid avidin as a step toward cold chain elimination
Authors: Bui‐Le Liem , Brogan Alex P. S. , Hallett Jason P.
Published: October 2020

The temperature sensitivity of vaccines and therapeutic proteins forces the distribution of life‐saving treatments to rely heavily on the temperature‐controlled (usually 2–8°C) supply and distribution network known as the cold chain. Here, using avidin as a model, we demonstrate how surface engineering could significantly increase the thermal stability of therapeutic proteins. A combination of spectroscopic (Fourier transform infrared, circular dichroism, and ultraviolet‐visible) and scattering techniques (dynamic light scattering, small‐angle, and wide‐angle X‐ray scattering) were deployed to probe the activity, structure, and stability of the model protein. Temperature‐dependent synchrotron radiation circular dichroism spectroscopy was used to demonstrate a significant increase in thermal stability, with a half denaturation temperature of 139.0°C and reversible unfolding with modified avidin returning to a 90% folded state when heated to temperatures below 100°C. Accelerated aging studies revealed that modified avidin retained its secondary structure after storage at 40°C for 56 days, equivalent to 160 days at 25°C. Furthermore, binding studies with multiple ligands revealed that the binding site remained functional after modification. As a result, this approach has potential as a storage technology for therapeutic proteins and the elimination of the cold chain, enabling the dissemination of life‐saving vaccines worldwide.
Exploration of the scientific papers and self‐assessment of students using the COVID‐19 case on biochemistry course
Authors: Anwar Yunita Arian Sani , Muti'ah Muti'ah
Published: October 2020

The coronavirus disease 2019 (COVID‐19) pandemic is a case that can be used as a biochemistry learning resource in relation to the topic of viruses. Learning to use cases will be effective if students are assigned to produce reports, articles, or other scientific papers. Self‐assessment can be used to assess the competencies that have been learnt in the writing process. This study aims to analyze the scientific papers and self‐assessment of students using the COVID‐19 pandemic case. It includes qualitative research with scientific paper and self‐assessment questionnaire analyses. The research sample was chemistry education study program students (N = 57) following biochemistry course, out of a population of 87 students. The results show that the students have a good understanding of explaining COVID‐19. Self‐assessment analysis shows that 80% of the students responded positively to eight statements; those who gave positive responses to each questionnaire statement were able to produce scientific papers. Good self‐assessment is in line with the ability of students to compile good scientific papers.
The most commonly injured nerves at surgery: A comprehensive review
Authors: Sharp Elizabeth , Roberts Melissa , Żurada‐Zielińska Agnieszka , Zurada Anna , Gielecki Jerzy , Tubbs Richard Shane , Loukas Marios
Published: October 2020

Iatrogenic nerve injury during surgery is a major source of concern for both patients and surgeons. This study aimed to identify the nerves most commonly injured during surgery, along with the commonly associated operative procedures. A literature search was conducted using the PubMed database to identify nerves commonly injured during surgery, along with the surgical procedure associated with the injury. The following 11 nerves, ranked in order with their associated surgical procedures, were found to be the most commonly injured: (a) intercostobrachial nerve in axillary lymph node dissections and transaxillary breast augmentations, (b) vestibulocochlear nerve in cerebellopontine tumor resections and vestibular schwannoma removals, c) facial nerve in surgeries of the inner ear and cheek region, (d) long thoracic nerve in axillary lymph node dissections, (e) spinal accessory nerve in surgeries of the posterior triangle of the neck and cervical lymph node biopsies, (f) recurrent laryngeal nerve in thyroid surgeries, (g) genitofemoral nerve in inguinal hernia and varicocele surgeries, (h) sciatic nerve in acetabular fracture repairs and osteotomies, (i) median nerve in carpal tunnel release surgeries, (j) common fibular nerve in varicose vein and short saphenous vein surgeries, and (k) ulnar nerve in supracondylar fracture surgeries. Although the root cause of iatrogenic nerve injury differs for each nerve, there are four unifying factors that could potentially decrease this risk for all peripheral nerves. These four influencing factors include knowledge of potential anatomical variations, visual identification of at‐risk nerves during the procedure, intraoperative nerve monitoring, and expertise of the surgeon.
Protect campus from natural sources of risk, including alligators
Authors: Sutton Halley
Published: October 2020

Tonya Womack, Director of Campus Safety and Security at Eckerd College, stepped on campus as a student and hasn't left. Since her graduation from the college in 2005, she's been employed by the campus, starting first with a stint in student life and finding her way to campus safety, where she's risen to the institution's top safety position. Womack said that one thing she loves about working at a smaller institution like Eckerd is the ability to dabble in different areas, and expand a variety of skill sets by working with different departments.
Metal Ion Promiscuity and Structure of 2,3‐Dihydroxybenzoic Acid Decarboxylase of Aspergillus oryzae
Authors: Hofer Gerhard , Sheng Xiang , Braeuer Simone , Payer Stefan E. , Plasch Katharina , Goessler Walter , Faber Kurt , Keller Walter , Himo Fahmi , Glueck Silvia M.
Published: October 2020

Broad substrate tolerance and excellent regioselectivity, as well as independence from sensitive cofactors have established benzoic acid decarboxylases from microbial sources as efficient biocatalysts. Robustness under process conditions makes them particularly attractive for preparative‐scale applications. The divalent metal‐dependent enzymes are capable of catalyzing the reversible non‐oxidative (de)carboxylation of a variety of electron‐rich (hetero)aromatic substrates analogously to the chemical Kolbe‐Schmitt reaction. Elemental mass spectrometry supported by crystal structure elucidation and quantum chemical calculations verified the presence of a catalytically relevant Mg2+ complexed in the active site of 2,3‐dihydroxybenoic acid decarboxylase from Aspergillus oryzae (2,3‐DHBD_Ao). This unique example with respect to the nature of the metal is in contrast to mechanistically related decarboxylases, which generally have Zn2+ or Mn2+ as the catalytically active metal.
Self‐Assembly of Benzimidazole‐Derived Tris‐NHC Ligands and AgI‐Ions to Hexanuclear Organometallic Cages and Their Unusual Transmetalation Chemistry
Authors: Nishad Rajeev C. , Rit Arnab
Published: October 2020

Multi‐ligand self‐assembly to attain the AgI‐N‐heterocyclic carbene (NHC)‐built hexanuclear organometallic cages of composition [Ag6(3 a,b)4](PF6)6 from the reaction of benzimidazole‐derived tris(azolium) salts [H3‐3 a,b](PF6)3 with Ag2O was achieved. The molecular structures of the cages were established by X‐ray diffraction studies along with NMR and MS analyses. The existence of a single assembly in solution was supported by diffusion‐ordered spectroscopy (DOSY) 1H NMR spectra. Further, transmetalation reactions of these self‐assembled complexes, [Ag6(3 a,b)4](PF6)6, with CuI/AuI‐ions provided various coinage metal‐NHC complexes having diverse molecular compositions, which included the first example of a hexanuclear CuI‐dodecacarbene complex, [Cu6(3 b)4](PF6)6.
Cyclic (Alkyl)(Amino)Carbene (CAAC) Gold(I) Complexes as Chemotherapeutic Agents
Authors: Proetto Maria T. , Alexander Kelsey , Melaimi Mohand , Bertrand Guy , Gianneschi Nathan C.
Published: October 2020

Cyclic (Alkyl)(Amino)Carbenes (CAACs) have become forceful ligands for gold due to their ability to form very strong ligand‐metal bonds. Inspired by the success of Auranofin and other gold complexes as antitumor agents, we have studied the cytotoxicity of bis‐ and mono‐CAAC‐gold complexes on different cancer cell lines: HeLa (cervical cancer), A549 (lung cancer), HT1080 (fibrosarcoma) and Caov‐3 (ovarian cancer). Further investigations aimed at elucidating their mechanism of action are described. This includes quantification of affinities for TrxR, evaluation of their bioavailability and determination of associated cell death process. Moreover, Transmission Electron Microscopy (TEM) was used to study morphological changes upon exposure. Noticeably, a significant reduction in non‐specific binding to serum proteins was observed with CAAC complexes when compared to Auranofin. These results confirm the potential of CAAC‐gold complexes in biological environments, which may result in more specific drug‐target interactions and decreased side effects.
Chiral Spirocyclic Phosphoric Acids and Their Growing Applications
Authors: Lin Xufeng , Wang Lei , Han Zhao , Chen Zhouli
Published: October 2020

Chiral spirocyclic phosphoric acids (SPAs) are introduced in 2010 and have been versatile catalysts capable of promoting a wide range of asymmetric organocatalytic reactions, such as multi‐component reactions, Friedel–Crafts reactions, Pictet–Spengler reactions, Fischer indolizations, cycloaddition reactions, desymmetrization reactions, dearomatization reactions, conjugate addition reactions and rearrangement reactions, etc. Moreover, a diverse range of applications in metal‐organic cooperative catalysis, organic photoredox catalysis, total synthesis, materials science and molecular recognition are beautifully illustrated. This account summarizes the past decade's advances in this field and highlights the selected but not comprehensive significant achievements.

What is the most favorite and original chemistry developed in your research group?

Developing SPINOL‐phosphoric acids (SPAs), TM‐SPINOL‐phosphoric acids (SPAs 2.0) and PCP‐derived planar chiral phosphoric acids (PPAs) for asymmetric catalysis.

What is the most important personality for scientific research?

Curiosity, optimism, self‐confidence and persistence.

What's your hobbies? What's your favorite book(s)?

I enjoy cooking. My favorite book is Journey to the West.

Who influences you mostly in your life?

My mother.

What is your favorite journal(s)?

The journals publishing the original and systematic work of synthetic chemistry.

Could you please give us some advices on improving Chinese Journal of Chemistry?

Fast review, fast publication, fast promotion via new media.
Role of eIF4A1 in triple‐negative breast cancer stem‐like cell‐mediated drug resistance
Authors: Raman Dayanidhi , Tiwari Amit K.
Published: October 2020

In cap‐dependent translation, the eukaryotic translation initiation factor 4A (eIF4A1) is an mRNA helicase is involved in unwinding of the secondary structure, such as the stem‐loops, at the 5′‐leader regions of the key oncogenic mRNAs. This facilitates ribosomal scanning and translation of the oncogenic mRNAs. eIF4A1 has a regulatory role in translating many oncoproteins that have vital roles in several steps of metastases. Sridharan et. al. have discovered and provide a novel insight into how eIF4A1 can play a regulatory role in drug resistance by influencing the levels of pluripotent Yamanaka transcription factors and ATP‐binding cassette (ABC) transporters in triple‐negative breast cancer (TNBC) stem‐like cells. These findings may help us understand the molecular underpinnings of chemoresistance, especially in established metastases in TNBC. Importantly, eIF4A1 may form a novel clinical target in metastatic TNBC and the drug eFT226 from Effector Therapeutics targeting eIF4A1 is already in phase1‐2 clinical trial.
Assessing the interrelationship corporate environmental responsibility, innovative strategies, cognitive and hierarchical CEO: A stakeholder theory perspective
Authors: Shah Syed Ghulam Meran , Sarfraz Muddassar , Ivascu Larisa
Published: October 2020

The objective of the study is to contemplate the effectiveness of cognitive CEO, hierarchical CEO, and innovative strategies on corporate environmental responsibility. Remarkably, the theoretical contribution has been revitalized while signifying the stakeholder theory perspective, which enunciates on the significance of corporate environmental responsibility. For empirical analysis, the data have been collected from the 1,070 listed Chinese firms for the year 2015–2019. The contributable concept of cognitive CEO has been formulated through CEO tenure, education, goodwill, and attainment of tacit knowledge while employing the DAE statistical technique. Hierarchical CEO and its three categorizations have been formulated by analyzing listed companies' profiles. Meanwhile, corporate environmental responsibility has been formulated, signifying the nine environmental attributes. It has been examined that innovative strategies boost corporate environmental responsibility, but its intensity is weak. Specifically, empirical underpinnings also envisage the cognitive CEO as compared to hierarchical CEO or medium hierarchical CEO, the vigorous promoter of corporate environmental responsibility.
Clinical efficacy of intravenous immunoglobulin therapy in critical ill patients with COVID‐19: a multicenter retrospective cohort study
Authors: Shao Ziyun , Feng Yongwen , Zhong Li , Xie Qifeng , Lei Ming , Liu Zheying , Wang Conglin , Ji Jingjing , Liu Huiheng , Gu Zhengtao , Hu Zhongwei , Su Lei , Wu Ming , Liu Zhifeng
Published: October 2020

Objective

Coronavirus disease 2019 (COVID‐19) outbreak is a major challenge all over the world, without acknowledged treatment. Intravenous immunoglobulin (IVIG) has been recommended to treat critical coronavirus disease 2019 (COVID‐19) patients in a few reviews, but the clinical study evidence on its efficacy in COVID‐19 patients was lacking.

Methods

325 patients with laboratory‐confirmed critical COVID‐19 were enrolled from 4 government‐designated COVID‐19 treatment centres in southern China from December 2019 to March 2020. The primary outcomes were 28‐ and 60‐day mortality, and the secondary outcomes were the total length of in‐hospital and the total duration of the disease. Subgroup analysis was carried out according to clinical classification of COVID‐19, IVIG dosage and timing.

Results

In the enrolled 325 patients, 174 cases used IVIG and 151 cases did not. The 28‐day mortality was improved with IVIG after adjusting confounding in overall cohort (P = 0.0014), and the in‐hospital and the total duration of disease were longer in the IVIG group (P < 0.001). Subgroup analysis showed that only in patients with critical type, IVIG could significantly reduce the 28‐day mortality, decrease the inflammatory response and improve some organ functions (all P < 0.05); the application of IVIG in the early stage (admission ≤ 7 days) with a high dose (> 15 g per day) exhibited significant reduction in 60‐day mortality in the critical‐type patients.

Conclusion

Early administration of IVIG with high dose improves the prognosis of critical‐type patients with COVID‐19. This study provides important information on clinical application of IVIG in the treatment of SARS‐CoV‐2 infection, including patient selection and administration dosage and timing.
Self‐Construal and Forgiveness Revisited: Replication and Extension
Authors: Major Jennifer L. L. , Wade Nathaniel G. , Brenner Rachel E.
Published: October 2020

Evidence suggests that people who have greater interdependent self‐construal forgive others more often because they are motivated to forgive to maintain the relationship. Furthermore, such forgiveness might lead to greater emotional well‐being. In this study, we examined the relationship between interdependent self‐construal and (a) decisional forgiveness and (b) emotional well‐being. We also tested models that included trait forgivingness and the motivation to forgive to maintain relationships. Results indicated that (a) trait forgivingness and relational motivations to forgive uniquely mediate the relationship between interdependent self‐construal and decisional forgiveness and (b) trait forgivingness may be a pathway from interdependent self‐construal to emotional well‐being.
The effect of concomitant COVID‐19 infection on outcomes in patients hospitalized with heart failure
Authors: Chatrath Nikhil , Kaza Nandita , Pabari Punam A. , Fox Kevin , Mayet Jamil , Barton Carys , Cole Graham D. , Plymen Carla M.
Published: October 2020

Aims

Patients with cardiovascular disease appear particularly susceptible to severe COVID‐19 disease, but the impact of COVID‐19 infection on patients with heart failure (HF) is not known.

This study aimed to quantify the impact of COVID‐19 infection on mortality in hospitalized patients known to have HF.

Methods and results

We undertook a retrospective analysis of all patients admitted with a pre‐existing diagnosis of HF between 1 March and 6 May 2020 to our unit. We assessed the impact of concomitant COVID‐19 infection on in‐hospital mortality, incidence of acute kidney injury, and myocardial injury. One hundred and thirty‐four HF patients were hospitalized, 40 (29.9%) with concomitant COVID‐19 infection. Those with COVID‐19 infection had a significantly increased in‐hospital mortality {50.0% vs. 10.6%; relative risk [RR] 4.70 [95% confidence interval (CI) 2.42–9.12], P < 0.001} and were more likely to develop acute kidney injury [45% vs. 24.5%; RR 1.84 (95% CI 1.12–3.01), P = 0.02], have evidence of myocardial injury [57.5% vs. 31.9%; RR 1.81 (95% CI 1.21–2.68), P < 0.01], and be treated for a superadded bacterial infection [55% vs. 32.5%; RR 1.67 (95% CI 1.12–2.49), P = 0.01].

Conclusions

Patients with HF admitted to hospital with concomitant COVID‐19 infection have a very poor prognosis. This study highlights the need to regard patients with HF as a high‐risk group to be shielded to reduce the risks of COVID‐19 infection.
CEO overconfidence and bank systemic risk: Evidence from U.S. bank holding companies
Authors: Liu Liang , Le Hang , Thompson Steve
Published: October 2020

Following the 2007–2008 financial crisis, the attention of financial regulators and academics has shifted from bank individual risk to bank systemic risk, that is, banks' exposure to future systemic crises. In this paper, we examine whether CEO overconfidence could explain cross‐sectional heterogeneity in the systemic risk of U.S. bank holding companies. Using measures of overconfidence based on CEOs' options exercise behaviour and language used in the Managerial Discussion and Analysis of the 10K‐filings, we find that banks with overconfident CEOs have higher systemic risk than their counterparts with non‐overconfident CEOs. Banks with overconfident CEOs also have higher holding of private mortgage‐backed securities and higher leverage. During the 2007–2008 financial crisis, banks with overconfident CEOs experienced higher realized systemic risk. Our work shows that the behaviour of overconfident bank CEOs could impose negative externalities beyond individual bank boundary.
Amniocentesis learning curve using a low‐cost simulation model to teach maternal–fetal medicine fellows
Authors: Ramirez‐Abarca Tania G. , Gallardo‐Gaona Juan M. , Lumbreras‐Marquez Mario I. , Seifert Sara M. , Rodriguez‐Sibaja Maria J. , Velazquez‐Torres Berenice , Ramirez‐Calvo Jose A. , Acevedo‐Gallegos Sandra
Published: October 2020

Objective

To describe the learning curve for amniocentesis among Maternal–Fetal Medicine (MFM) fellows using a low‐cost simulation model in Mexico.

Methods

Fourteen first‐ and second‐year MFM fellows with no previous experience in amniocentesis participated in this single‐center prospective study from March to June of 2019. The study was approved by the Institutional Review Board at the Instituto Nacional de Perinatologia and written informed consent was obtained from all participants. After an introductory course based on a standardized technique for amniocentesis, each fellow performed this procedure using a low‐cost simulation model; experienced operators supervised the procedures. Learning curves were then created using cumulative sum analysis. Thresholds for acceptable and unacceptable failure rates were defined as 10% and 25%, respectively.

Results

Experienced MFM specialists evaluated 3675 procedures. On average, MFM fellows performed 263 ± 53 procedures. The mean number to achieve competence was 255 ± 53. The overall failure rate among the trainees was 16%.

Conclusion

We describe individual learning curves for amniocentesis among MFM fellows using a low‐cost simulation model. This approach allows direct assessment of proficiency in amniocentesis before clinical practice.