bluuebunny/crossref_metadata_2025 huggingface dataset:
Self‐Immolative Amphiphilic Poly(ferrocenes) for Synergistic Amplification of Oxidative Stress in Tumor Therapy
Authors: Xu Jie , Tan Jiajia , Song Chengzhou , Zhang Guoying , Hu Xianglong , Liu Shiyong
Published: May 2023

Amphiphilic self‐immolative polymers (SIPs) can achieve complete degradation solely through one triggerable event, which potentially optimize the blood clearance and uncontrollable/inert degradability for therapeutic nanoparticles. Herein, we report self‐immolative amphiphilic poly(ferrocenes), BPnbs‐Fc, composed by self‐immolative backbone and aminoferrocene (AFc) side chains as well as end‐capping poly(ethylene glycol) monomethyl ether. Upon triggering by tumor acidic milieu, the BPnbs‐Fc nanoparticles readily degrade to release azaquinone methide (AQM) moieties, which can rapidly deplete intracellular glutathione (GSH) to cascade release AFc. Furthermore, both AFc and its product Fe2+ can catalyze intracellular hydrogen peroxide (H2O2) into highly reactive hydroxyl radicals (⋅OH), thus amplifying the oxidative stress of tumor cells. Rational synergy of GSH depletion and ⋅OH burst can efficiently inhibit tumor growth by the SIPs in vitro and in vivo. This work provides an elegant design to adopt innate tumor milieu‐triggerable SIPs degradation to boost cellular oxidative stress, which is a promising candidate for precision medicine.
High‐Performance Organic Solar Cells Containing Pyrido[2,3‐b]quinoxaline‐Core‐Based Small‐Molecule Acceptors with Optimized Orbit Overlap Lengths and Molecular Packing
Authors: Xu Tongle , Luo Zhenghui , Ma Ruijie , Chen Zhanxiang , Dela Peña Top Archie , Liu Heng , Wei Qi , Li Mingjie , Zhang Cai'e , Wu Jiaying , Lu Xinhui , Li Gang , Yang Chuluo
Published: May 2023

The central core in A‐DA1D‐A‐type small‐molecule acceptor (SMAs) plays an important role in determining the efficiency of organic solar cells (OSCs), while the principles governing the efficient design of SMAs remain elusive. Herein, we developed a series of SMAs with pyrido[2,3‐b]quinoxaline (PyQx) as new electron‐deficient unit by combining with the cascade‐chlorination strategy, namely Py1, Py2, Py3, Py4 and Py5. The introduction of chlorine atoms reduces the intramolecular charge transfer effects but elevates the LUMO values. Density functional theory (DFT) reveals that Py2 with ortho chlorine substituted PyQx and Py5 with two chlorine atoms yield larger dipole moments and smaller π⋅⋅⋅π stacking distances, as compared with the other three acceptors. Moreover, Py2 shows the strongest light absorption capability induced by extended orbit overlap lengths and more efficient packing structures in the dimers. These features endow the best device performance of Py2 due to the better molecular packing and aggregation behaviors, more suitable domain sizes with better exciton dissociation and charge recombination. This study highlights the significance of incorporating large dipole moments, small π⋅⋅⋅π stacking distances and extended orbit overlap lengths in dimers into the development of high‐performance SMAs, providing insight into the design of efficient A‐DA1D‐A‐type SMAs for OSCs.
Bio‐Templated Chiral Zeolitic Imidazolate Framework for Enantioselective Chemoresistive Sensing
Authors: Kim Minkyu , Han Moon Jong , Lee Hansol , Flouda Paraskevi , Bukharina Daria , Pierce Kellina J. , Adstedt Katarina M. , Buxton Madeline L. , Yoon Young Hee , Heller William T. , Singamaneni Srikanth , Tsukruk Vladimir V.
Published: May 2023

Chiral metal–organic frameworks (MOFs) have gained rising attention as ordered nanoporous materials for enantiomer separations, chiral catalysis, and sensing. Among those, chiral MOFs are generally obtained through complex synthetic routes by using a limited choice of reactive chiral organic precursors as the primary linkers or auxiliary ligands. Here, we report a template‐controlled synthesis of chiral MOFs from achiral precursors grown on chiral nematic cellulose‐derived nanostructured bio‐templates. We demonstrate that chiral MOFs, specifically, zeolitic imidazolate framework (ZIF), unc‐[Zn(2‐MeIm)2, 2‐MeIm=2‐methylimidazole], can be grown from regular precursors within nanoporous organized chiral nematic nanocelluloses via directed assembly on twisted bundles of cellulose nanocrystals. The template‐grown chiral ZIF possesses tetragonal crystal structure with chiral space group of P41, which is different from traditional cubic crystal structure of I‐43 m for freely grown conventional ZIF‐8. The uniaxially compressed dimensions of the unit cell of templated ZIF and crystalline dimensions are signatures of this structure. We observe that the templated chiral ZIF can facilitate the enantiotropic sensing. It shows enantioselective recognition and chiral sensing abilities with a low limit of detection of 39 μM and the corresponding limit of chiral detection of 300 μM for representative chiral amino acid, D‐ and L‐ alanine.
Improving water resistance property of starch straw by synergistic effects of chemical crosslinking, physical barrier, and surface modifications
Authors: Yang Mao , Fu Jun , Alee Mahafooj , Duan Qingfei , Xie Huifang , Ali Amjad , Liu Hongsheng , Chen Ling , Yu Long
Published: May 2023

Starch straws are developed by focusing on improving the critical weakness of all starch‐based materials: moisture sensitivity. Various technologies including blending (with hydrogel carrageen), chemical crosslinking (using citric and boric acids, and furfural), physical barrier (using talc), and surface modifications (by adding stearic acid, or hot oxalic acids) are evaluated, and then synergized in this study. The materials and products are characterized by Fourier transform infrared spectroscopy, contact angle, mechanical properties, water solubility and water absorption. All the trends of individual modification are similar to previous work but it was found that the influence of some modifications on the extruded straws was significantly different from that of the casting films reported previously since extrusion with high shear stress can destroy chemical and physical crosslinking or network formed. It was found that there was a maximum acid content to improve the water sensitivity since the excessive amount of acid could degrade starch and have more damage to the crosslinking during extrusion, resulting in decreasing mechanical properties and increasing solubility. On the other hand, some synergic functions, like crosslinked by additional citric acid and surface treatment by hot oxalic acid, were observed. The promising starch straws are developed based on synergic methodologies, in which typical samples were prepared by crosslinking using citric (1 w%), boric (2 w%), talc (3 w%), and stearic acids (1 w%) and treated with hot oxalic acids for 2 s. The optimized straw can be smoothly processed, reduced water absorption significantly (55.3%), and mechanical properties (modulus) increased about 54% compared with neat starch one after being immersed in water at room temperature (25°C) for 20 min. This synergic strategy provides a useful guideline for developing starch‐based materials with low moisture sensitivity.
On the regional control problem of the bilinear wave equation
Authors: Ait Aadi Abderrahman , Zerrik El Hassan , Ouhafsa Mohamed
Published: May 2023

The present research deals with regional optimal control problem of the bilinear wave equation evolving on a spatial domain
. Such an equation is excited by bounded controls that act on the velocity term. It addresses the tracking of a desired state all over the time interval
only on a subregion
of
with minimum energy. Then, we prove that an optimal control exists and is characterized as a solution to an optimality system. Algorithm for the computation of such a control is given and successfully illustrated through simulations.
Well‐posedness and Mittag–Leffler stability for a nonlinear fractional telegraph problem
Authors: Othmani Sakina , Tatar Nasser‐Eddine
Published: May 2023

The ordinary diffusion models in continuous media are derived from basic principles: Conservation of energy and momentum. The classical telegraph equation is one of the earliest and most commonly used equation to describe the transmission of electromagnetic waves. In fractal and disordered media, to capture the complex diffusion feature, we consider rather fractional models. Indeed, the mean square displacement in anomalous media is no longer proportional to the time but rather proportional to a power of time whose exponent may be between zero and one or between one and two. This is the case for the present fractional telegraph equation in the presence of non‐negligible voltage wave. Here, the well‐posedness and stability of a telegraph problem with two time‐fractional derivatives is discussed. In addition to being a noninteger problem, the equation in the model is subject to a nonlinear source as well as a nonlinear lower order fractional derivative term. First, the well‐posedness in an appropriate underlying space is established by the use of resolvent operators. Then, it is proved that, despite the presence of these nonlinearities, solutions are Mittag–Leffler stable. This confirms (and extends) the fact that the lower order term plays the role of a damper in the fractional case. To this end, we combine the energy method with some properties of the Caputo fractional derivative.
Development of delivery strategies for CRISPR‐Cas9 genome editing
Authors: Liu Qi , Yang Jianhui , Xing Yumeng , Zhao Yu , Liu Yang
Published: May 2023

The clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR‐related protein 9 (Cas9) genome editing system has attracted much attention due to its powerful genome editing capacity. However, CRISPR‐Cas9 components are easily degraded by acids, enzymes, and other substances in the body fluids after entering the organism, thus efficiently delivering the CRISPR‐Cas9 system into targeted organs or cells has been a central theme for promoting the application of CRISPR‐Cas9 technology. Although several physical methods and viral vectors have been developed for CRISPR‐Cas9 delivery, their clinical application still suffers from disadvantages, such as the risks of mutagenesis, cell damage, and poor specificity. As an alternative, non‐viral nanocarriers hold great promise for circumventing these challenges. Furthermore, with aim to realize more efficient and precise genome editing and reduce the undesirable side effects, stimuli‐responsive nanocarriers are designed for the spatiotemporal CRISPR‐Cas9 delivery in responsive to various stimuli. In this review, we will summarize the recent progress in delivery strategies for CRISPR‐Cas9 genome editing. The mechanisms and advantages of these strategies were reviewed, providing a comprehensive review of the rational design of materials and techniques for efficient and precise genome editing. At last, the potential challenges of current CRISPR‐Cas9 delivery are discussed.
Visualizing timeline‐anchored comments enhanced social presence and information searching in video‐based learning
Authors: Chen Yue , Gao Qin
Published: May 2023

Numerous learners watch knowledgeable videos with comments or annotations anchored to the video timeline. These comments are learners’ discussions with abundant informational and social content along with video timelines, but the content is usually fragmented and scattered. To extract, organize, and highlight useful information from the discussion, we adopted text mining approaches and designed an interactive visualization tool in the lecture interface for learners, including the following components along with the video timeline: (1) the relevance of comments to the lecture, (2) the comment topics throughout the lecture, and (3) the difficulty level perceived by learners. We conducted a lab experiment with 24 students to examine the effects of the visualization tool on the learning process and outcomes. We found that learners perceived a significantly higher social presence and performed better in open‐book quizzes, searching tasks, and summarizing lectures using the visualization tool. This suggests that the visualization of timeline‐anchored commenting potentially facilitates learners’ participation in discussions and contributions to the learning community.
Amenyunnaosides A–C, Three New Neolignans Isolated from Amentotaxus yunnanensis and Their Anti‐inflammatory Activities
Authors: Trung Thanh Nguyen , Thi Thuy La , Thi Xuyen Do , Quynh Mai Le , Van Hai Do , Sinh Khang Nguyen , Thi Trang Do , Huu Tai Bui , Van Kiem Phan
Published: May 2023

Phytochemical study on the leaves of Amentotaxus yunnanensis led to the isolation of seventeen phenolic compounds including sixteen neolignans and lignans, and one flavone glycoside. Three among the isolates were previously unreported neolignans and named as amenyunnaosides A–C, respectively. Their structures were elucidated by extensive analyses of HR‐ESI‐MS, 1D and 2D NMR, and ECD spectra. The isolated neolignans potentially inhibited NO production in LPS‐activated RAW264.7 cells with their IC50 values ranging from 11.05 to 44.07 μM, compared to that of the positive control compound, dexamethasone, IC50 value of 16.93 μM. Additionally, amenyunnaoside A dose‐dependently reduced production of IL‐6 and COX‐2 but did not effect to that of TNF‐α at concentrations of 0.8, 4, and 20 μM.
Inhibition of TGF‐β type I receptor by SB505124 down‐regulates osteoblast differentiation and mineralization of human mesenchymal stem cells
Authors: Almuraikhi Nihal
Published: May 2023

Numerous signaling pathways are well‐known in osteoblastic differentiation of human bone marrow mesenchymal stem cells (hBMSCs), including transforming growth factor‐beta (TGF‐β) signaling pathway, which sends signals through specific type I and II serine/threonine kinase receptors. However, the key role of TGF‐β signaling during bone formation and remodeling is yet to be studied. A TGF‐β type I receptor inhibitor, SB505124, discovered through a screening of a small molecule library for their effect of osteoblast differentiation of hBMSCs. Alkaline phosphatase quantification and staining were tested as indicators of osteoblastic differentiation and Alizarin red staining was tested as an indicator of in vitro mineralization. Changes in gene expressions were assessed using qRT‐PCR. SB505124 showed significant inhibition of the osteoblast differentiation of hBMSCs, as confirmed by reduced alkaline phosphatase, in vitro mineralization, and downregulation of osteoblast‐associated gene expression. To further understand the molecular mechanisms involved in the inhibition of the TGF‐β type I receptor, we assessed the effects on signature genes of several signaling pathways identified in the osteoblast differentiation of hBMSCs. SB505124 downregulated gene expression of many genes linked to osteoblast‐related signaling pathways including TGF‐β, insulin, focal adhesion, Notch, Vitamin D, interleukin (IL)‐6, osteoblast signaling, and cytokines and inflammatory. We report TGF‐β type I receptor inhibitor (SB505124) is a potent inhibitor of osteoblastic differentiation of hBMSCs that could be a valuable innovative therapeutic tool to cure bone disorders with increased bone formation, besides its potential use to treat patients with cancer and fibrosis.
Autophagy‐related gene PXN as a prognostic marker: Promotion of ovarian cancer progression by suppressing the p110β/Vps34/Beclin1 pathway
Authors: Wu Qiaoling , Cui Zhaolei , Jiang Shan , Xia Hongmei , Liu Li , You Yiqing , Sun Yang
Published: May 2023

Among gynecological malignancies, ovarian cancer has the highest mortality rate and has sparked widespread interest in studying the mechanisms underlying ovarian cancer development. Based on TCGA and GEO databases, we investigated the highly expressed autophagy‐related genes that determine patient prognosis using limma differential expression and Kaplan–Meier survival analyses. The biological processes associated with these genes were also predicted using GO/KEGG functional enrichment analysis. CCK‐8, cell scratch, and transwell assays were used to investigate the effects of PXN on the proliferation, migration, and invasion abilities of ovarian cancer cells. Transmission electron microscopy was used to observe the autophagosomes. The expression of autophagy proteins and the PI3K/Akt/mTOR and p110β/Vps34/Beclin1 pathway proteins in ovarian cancer cells was detected using western blot; autophagy protein expression was further detected and localized using cellular immunofluorescence. A total of 724 autophagy‐related genes were found to be overexpressed in ovarian ‐cancer tissues, with high expression of PEX3, PXN, and RB1 associated with poor prognosis in patients (p < .05). PXN activates and regulates signaling pathways related to cellular autophagy, ubiquitination, lysosomes, PI3K‐Akt, and mTOR. Autophagosomes were observed in all cell groups. The increase in PXN gene expression promoted the proliferation, migration, and invasion of ovarian cancer cells, increased the expression of SQSTM1/p62 protein, decreased LC3II/LC3Ⅰ, inhibited the phosphorylation of Akt and mTOR proteins, and suppressed the expression of PI3K(p110β) and Beclin1 proteins. The decrease in PXN expression also confirmed these changes. Thus, PXN is highly expressed during ovarian cancer and is associated with poor patient prognosis. It may promote ovarian cancer cell proliferation, migration, and invasion by inhibiting cellular autophagy via suppression of the p110β/Vps34/Beclin1 pathway.
Dispersion Function of a Protein, DP‐1, Identified inCollimonas sp. D‐25, for the Synthesis of Gold Nanoparticles
Authors: Tang Donglin , Kato Yugo , Zhang Dingkun , Negishi Lumi , Kurumizaka Hitoshi , Hirata Takafumi , Nakakido Makoto , Tsumoto Kouhei , Shuji Fujisawa , Tsuguyuki Saito , Okumura Taiga , Nagata Koji , Suzuki Michio
Published: May 2023

Collimonas sp. (D‐25), found in the soil of Akita Prefecture, is a gram‐negative bacterium with the ability to synthesize gold nanoparticles (AuNPs). During the synthesis of AuNPs, one specific protein (DP‐1) was found to have disappeared in the sonicated solution of the bacterium. Recombinant DP‐1 (rDP‐1) fromEscherichia coliBL21 (DE3) was used to study the effect of DP‐1 on the synthesis of AuNPs. AuNPs synthesized with rDP‐1 result in small, stabilized nanoparticles. AuNPs synthesized by DP‐1 retained the stability of both the dispersion and nano‐size particles under high salt concentrations. Isothermal titration calorimetry was employed to investigate the bonding ratio of rDP‐1 to AuNPs. Several thousand rDP‐1 proteins are attached to the surface of an AuNP to form a protein corona containing multiple layers. These results suggest that DP‐1 obtained from D‐25 has a size and stability control function during AuNP synthesis.
Peptide Amphiphilic Supramolecular Nanogels: Competent Host for Notably Efficient Lipase‐Catalyzed Hydrolysis of Water‐Insoluble Substrates
Authors: Pal Sudeshna , Khan Aftab Hossain , Chowdhury Monalisa , Das Prasanta Kumar
Published: May 2023

The present work depicts the development of stable nanogels in an aqueous medium that were exploited for efficient surface‐active lipase‐catalyzed hydrolysis of water‐insoluble substrates. Surfactant‐coated gel nanoparticles (neutral NG1, anionic NG2, and cationic NG3) were prepared from peptide amphiphilic hydrogelator (G1, G2, and G3, respectively) at different hydrophilic and lipophilic balance (HLB). Chromobacterium viscosum (CV) lipase activity towards hydrolysis of water‐insoluble substrates (p‐nitrophyenyl‐n‐alkanoates (C4–C10)) in the presence of nanogels got remarkably improved by ~1.7–8.0 fold in comparison to that in aqueous buffer and other self‐aggregates. An increase in hydrophobicity of the substrate led to a notable improvement in lipase activity in the hydrophilic domain (HLB>8.0) of nanogels. The micro‐heterogeneous interface of small‐sized (10–65 nm) nanogel was found to be an appropriate scaffold for immobilizing surface‐active lipase to exhibit superior catalytic efficiency. Concurrently, the flexible conformation of lipase immobilized in nanogels was reflected in its secondary structure having the highest α‐helix content from the circular dichroism spectra.
Narcolepsy following COVID‐19: A case report and review of potential mechanisms
Authors: Roya Yazdani , Farzaneh Barzkar , Mostafa Almasi‐Dooghaee , Mahsa Shojaie , Babak Zamani
Published: May 2023

Key Clinical Message

The immune activation in COVID‐19 may trigger narcolepsy in vulnerable patients. We suggest clinicians carefully evaluate patients with post‐COVID fatigue and hypersomnia for primary sleep disorders, specifically narcolepsy.

The patient is a 33‐year‐old Iranian woman without a significant past medical history with the full range of narcolepsy symptoms that started within 2 weeks after her recovery from COVID‐19. Sleep studies revealed increased sleep latency and three sleep‐onset rapid eye movement events, compatible with a narcolepsy‐cataplexy diagnosis.
A case of vagal cephalgia as a manifestation of a lung neoplasm—A case report and review of literature
Authors: Sanker Vivek , Devaragudi Sanjana , Shariff Sanobar , Deva Sheryl , Mathew Robert , Gupta Umang
Published: May 2023

Key Clinical Message

Lung cancer can present with unilateral atypical facial pain, a rare symptom due to vagus nerve involvement or paraneoplastic syndrome. This manifestation is usually missed, delaying the diagnosis and prognosis. We discuss a case of a 45‐year‐old male who presented with right‐sided hemifacial pain and with normal neurological investigations.
Racial animosity and Black financial advisor underrepresentation
Authors: DiBartolomeo Jeffrey A. , Kothakota Michael G. , Parks‐Stamm Elizabeth J. , Tharp Derek T.
Published: May 2023

This study provides compelling evidence for Black underrepresenation in the financial advisor industry. Using a dataset of all U.S. securities‐licensed individuals (N = 642,543), we first estimate the racial and ethnic composition of the industry using an algorithm that accounts for name, gender, and location. Second, we use a dataset enhanced by a commercial vendor to restrict the analysis to only those identified as working as financial advisors (n = 237,435). Using Google search volume for a racial epithet as a proxy for area racism, we find that greater racism in a market is associated with greater Black advisor underrepresentation. Overall, we estimate at the individual level that 10.1% of financial advisors are Black (relative to 13.4% of the U.S. population). Furthermore, our results suggest market‐level racial animosity toward Blacks is negatively associated with Black advisor representation. We estimate a difference of 0.9 percentage points when comparing markets with the highest and lowest levels of animosity. For the average market with an estimated 11.4% Black advisor representation, an increase of 0.9 percentage points would represent a 7.9% increase in Black advisor representation.
Hydration Rearrangement in the 4‐Aminobenzonitrile−(H2O)2 Cluster Induced by Photoionization: The Effect of Solvent‐Solvent Interactions
Authors: Matsuno Risako , Dopfer Otto , Fujii Masaaki , Miyazaki Mitsuhiko
Published: May 2023

The interplay between solute‐solvent and solvent‐solvent interactions plays an essential role in solvation dynamics that has important effects on the mechanism and dynamics of chemical reactions in solution. In this study, the rearrangement of the hydration shell induced by photoionization of a solute molecule is probed in a state‐ and isomer‐specific manner by resonant multiphoton ionization detected IR spectroscopy of the prototypical 4‐aminobenzonitrile−(H2O)2 cluster produced in a molecular beam. IR spectra reveal that the water molecules form a cyclic solvent network around the CN group in the initial neutral state (S0). Different from the singly‐hydrated cluster, in which either the CN or the NH2 group is hydrated, hydration of the NH2 group is not observed in the dihydrated cluster. IR spectra obtained after ionizing the solute molecule into the cation ground state (D0) exhibit features ascribed to both NH‐bound and CN‐bound isomers, indicating that water molecules migrate from the CN to the NH site upon ionization with a yield depending on the ionization excess energy. Analysis of the IR spectra as a function of the excess energy shows that migration produces two different NH2 solvated structures, namely (i) the most stable structure in which both N−H bonds are singly hydrated and (ii) the second most stable isomer in which one of the N−H bonds is hydrated by a H‐bonded (H2O)2 dimer. The product branching ratio of the two isomers depends on the excess energy. The role of the water‐water interaction in the hydration rearrangement is discussed based on the potential energy landscape. Solvation dynamics plays an important role in reaction mechanisms in the condensed phase, where not only solute‐solvent solvation but also solvent‐solvent interactions have a significant influence on the dynamics. Thus, the investigation of solvation dynamics at the molecular level substantially contributes to our understanding of the reaction mechanism. In this study, the dihydrated cluster of 4ABN was utilized as a model for the first solvation layer to elucidate solvent motions induced by ionization of the solute and the role of W−W interactions for the solvent relaxation.
Enzymatic Synthesis of l‐Methionine Analogues and Application in a Methyltransferase Catalysed Alkylation Cascade**
Authors: Mohr Michael K. F. , Saleem‐Batcha Raspudin , Cornelissen Nicolas V. , Andexer Jennifer N.
Published: May 2023

Chemical modification of small molecules is a key step for the development of pharmaceuticals. S‐adenosyl‐l‐methionine (SAM) analogues are used by methyltransferases (MTs) to transfer alkyl, allyl and benzyl moieties chemo‐, stereo‐ and regioselectively onto nucleophilic substrates, enabling an enzymatic way for specific derivatisation of a wide range of molecules. l‐Methionine analogues are required for the synthesis of SAM analogues. Most of these are not commercially available. In nature, O‐acetyl‐l‐homoserine sulfhydrolases (OAHS) catalyse the synthesis of l‐methionine from O‐acetyl‐l‐homoserine or l‐homocysteine, and methyl mercaptan. Here, we investigated the substrate scope of ScOAHS from Saccharomyces cerevisiae for the production of l‐methionine analogues from l‐homocysteine and organic thiols. The promiscuous enzyme was used to synthesise nine different l‐methionine analogues with modifications on the thioether residue up to a conversion of 75 %. ScOAHS was combined with an established MT dependent three‐enzyme alkylation cascade, allowing transfer of in total seven moieties onto two MT substrates. For ethylation, conversion was nearly doubled with the new four‐enzyme cascade, indicating a beneficial effect of the in situ production of l‐methionine analogues with ScOAHS.
Deoxygenative Radical Boration of Inert Amides via a Combination of Relay and Cooperative Catalysis
Authors: Jiang Feng , Li Jing'an , Wang Xiaoming
Published: May 2023

Invited for the cover of this issue is the group of Prof. Xiaoming Wang at the Shanghai Institute of Organic Chemistry and Hangzhou Institute for Advanced Study, University of the Chinese Academy of Sciences. The image depicts a combination of relay and cooperative catalysis with a triple iridium–photoredox–organocatalysis system to achieve an unprecedented reductive boration of amides. Read the full text of the article at 10.1002/chem.202301199.
A Bacterial Cytochrome P450 Enzyme Catalyzes Multistep Oxidation Reactions in Pyrroindomycin Biosynthesis
Authors: Wang Jiabao , Xu Yu , Chen Dandan , Tao Jiang , Wang Hongbo , Liu Wen
Published: May 2023

Comprehensive Summary

Cytochrome P450 enzymes (P450s) belong to a large family of oxidative hemeproteins and catalyze highly diverse oxygenation reactions that are involved in the biosynthesis of various natural products. Here, we report a multifunctional cytochrome P450 enzyme, PyrE2, which catalyzes the regioselective, successive 6‐electron oxidation of an inert methyl group to produce a carboxyl product through formation of the hydroxyl and aldehyde intermediates in pyrroindomycin biosynthesis. The time‐course biotransformation was characterized by the presence of the hydroxyl and aldehyde intermediates, the lag of the formation of the carboxyl product, and the subsequent loss of both intermediates, indicating that each 2‐electron oxidation exhibits the distributive mechanism that requires substrate binding and product releasing. Bioinformatics analysis shows that the homologs of pyrE2 are common in the gene clusters of the spirotetronates varying in the oxidative state of the corresponding exocyclic carbon, indicating the generality and diversity of P450‐catalyzed oxygenation in related biosynthetic pathways.
Query cost estimation in graph databases via emphasizing query dependencies by using a neural reasoning network
Authors: He Zhenzhen , Yu Jiong , Gu Tiquan , Li Zhe , Du Xusheng , Li Ping
Published: May 2023

With the increasing complexity of graph queries, query cost estimation has become a key challenge in graph databases. Accurate estimation results are critical for database administrators or database management systems to perform query processing or optimization tasks. An efficient and accurate estimation model can improve the estimation quality and make the produced results credible. Although learning‐based methods have been applied in query cost estimation, most of them are directed at relational queries and cannot be directly used for graph queries. Furthermore, most estimation approaches focus on the correlations between predicates or columns. The dependencies between query schema and query filter conditions and the correlation between query schema are ignored. In this study, we construct a novel deep learning model composed of reasoning and retrieval processes that can accurately capture the potential logical relationships in graph queries. This solves the above problems to some extent. In addition, we propose a query estimation framework that divides the estimation task into query workload generation, training data collection, feature extraction and encoding, and estimation model construction. The results of the experiment on real‐world datasets show that our estimation model can improve the estimation quality and outperforms other compared deep learning models in terms of estimation accuracy.
Acknowledgment of patient in sense behaviors using bidirectionalConvLSTM
Authors: Singh Upendra , Gupta Puja , Shukla Mukul , Sharma Varsha , Varma Sunita , Sharma Sumit Kumar
Published: May 2023

Recognizing patient activity in real‐time from video or images collected by a CCTV camera available in the hospital during a Covid‐19 situation has proven challenging. The dilemma of patient activity recognition is identifying and recognizing a patient's various actions in a series of videos. The process presented in our paper needs to achieve unrestricted, generic behavior in videos. Detecting events in any video is often difficult because we use Bidirectional ConvLSTM to create a robust patient in the sense behaviors (PSB) framework capable of eliminating certain barriers. To begin this paper by proposing a new Bidirectional ConvLSTM for establishing a stable PSB scheme. Our proposed model is capable of accurately predicting patient's behaviors like seated, standing, and so on. Using Bidirectional ConvLSTM, learning information from a pre‐trained model is an excellent place to start for rapidly developing a new PSB system using a current PSB database, as both the source and target datasets are critical. All parameters are frozen in a pre‐trained PSB device. Then, using the UCI and HMDB51 dataset to train the model, variables and local relations are progressively fixed. A novel PSB framework is developed using the target dataset. Relevant tests are conducted using commonly used research indices to assess prediction precision accuracy. They acknowledge six patient's behavior with a weighted accuracy rate of 92%. For recognizing novel activity, laying, the precision of a corresponding prediction is the best, 91%, of all six test results. The proposed work uses bidirectional ConvLSTM with modified activation layers to sense the patients' behavior. This article may be a patient activity recognition system to identify an individual. It takes a clip of COVID‐19 patients as input and looks for matches inside the hold‐on images.
Photocatalytic Z‐scheme Overall Water Splitting: Insight into Different Optimization Strategies for Powder Suspension and Particulate Sheet Systems
Authors: Wei Yuxue , Zhang Zhiyuan , Wang Wenjing , Song Zhimin , Cai Mengdie , Sun Song
Published: May 2023

Achieving solar light‐driven photocatalytic overall water splitting is the ideal and ultimate goal for solving energy and environment issues. Photocatalytic Z‐scheme overall water splitting has undergone considerable development in recent years; specific approaches include a powder suspension Z‐scheme system with a redox shuttle and a particulate sheet Z‐scheme system. Of these, a particulate sheet has achieved a benchmark solar‐to‐hydrogen efficiency exceeding 1.1 %. Nevertheless, owing to intrinsic differences in the components, structure, operating environment, and charge transfer mechanism, there are several differences between the optimization strategies for a powder suspension and particulate sheet Z‐scheme. Unlike a powder suspension Z‐scheme with a redox shuttle, the particulate sheet Z‐scheme system is more like a miniaturized and parallel p/n photoelectrochemical cell. In this review, we summarize the optimization strategies for a powder suspension Z‐scheme with a redox shuttle and particulate sheet Z‐scheme. In particular, attention has been focused on choosing appropriate redox shuttle and electron mediator, facilitating the redox shuttle cycle, avoiding redox mediator‐induced side reactions, and constructing a particulate sheet. Challenges and prospects in the development of efficient Z‐scheme overall water splitting are also briefly discussed.
Clicking together Alkynes and Tetracyanoethylene
Authors: Nielsen Mogens Brøndsted
Published: May 2023

The [2+2] cycloaddition – retro‐electrocyclization (CA‐RE) reaction allows ready synthesis of redox‐active donor‐acceptor chromophores from an electron‐rich alkyne and electron‐poor olefins like tetracyanoethylene (TCNE). The detailed mechanism of the reaction has been subject of both computational and experimental studies. While several studies point towards a stepwise mechanism via a zwitterionic intermediate for the first step, the cycloaddition, the reaction follows neither simple second‐order nor first‐order kinetics. Recent studies have shown that the kinetics can be understood if an autocatalytic step is introduced in the mechanism, in which complex formation with the donor‐substituted tetracyanobutadiene (TCBD) product possibly facilitates nucleophilic attack of the alkyne onto TCNE, generating the zwitterionic intermediate of the CA step. This Concept highlights the convenient use of the “click‐like” CA‐RE reaction to obtain elaborate donor‐acceptor chromophores and the recent mechanistic results.
Growth and Variable Temperature Hall Effect Study of SrPb3Br8Crystal with Low Phonon Energy
Authors: Xiao Xiao , Wang Jie , Zhang Shaoqing , Peng Jing , Xiong Zhengbin , Liu Xinyao , Huang Wei , Chen Baojun , He Zhiyu
Published: May 2023

Transparent and homogeneous SrPb3Br8single crystals with the size of Ø25 mm × 50 mm are grown by the modified vertical Bridgman method. X‐ray diffraction results reveal that the middle part of the crystal is pure in chemical compositions, while the tip part contains low content of Sr(PbBr3)2(H2O)5. X‐ray photoelectron spectroscopy analysis points out the absorption to C, O‐containing substances of the pristine surfaces of SrPb3Br8wafers. The Raman results prove the low phonon energy of the SrPb3Br8(116 cm−1). Transmission spectra demonstrate its wide transparent range (0.37–25 µm) and high transmittance in the mid‐infrared range except for several absorption lines. Moreover, Hall measurements show that the SrPb3Br8sample is n‐type conductive at 110–300 K, and the Hall coefficientRH, resistivityρand mobilityµHdecrease as temperature increases while the carrier concentrationnhas an opposite trend. The conduction mechanism and scattering mechanism of SrPb3Br8crystal at different temperatures has been studied by analyzing ln(|RH|)−T−1,n−TandµH−Tcurves, and the dominant donor defect ionization energyEDis calculated to be 0.077 eV.
Synthesis of ZnO Crystal with Micro‐Nano Structures by a Continuous Co‐Precipitation Method: Morphological Evolution and Mechanism Analysis
Authors: Zhong Pei , Huang Qingshan , Wang Zhenzhen , Zhang Haidong , Xu Dongmei , Li Ping
Published: May 2023

ZnO crystals are employed in numerous industries, but precisely controlling their morphologies is still challenging. In this work, a continuous flow process for synthesizing ZnO crystals is developed based on the co‐precipitation method. ZnO crystals at different morphologies, including needle‐like, rod‐like, flower‐like, spindle‐like, and nanospheres, are successfully prepared at low temperature. The influence of reaction temperature, pH value, ZnCl2 feeding concentration, and reaction time on the morphology, size, and purity of ZnO crystals is systematically investigated. The results of X‐ray diffraction show that the high‐purity ZnO can only be produced when the reaction temperature is above 75 °C. The band gap energies of ZnO evaluated by UV–vis diffuse reflectance spectroscopy increase with the synthesis temperature. According to scanning electron microscope (SEM) findings, the size of ZnO crystals is regulated by controlling the reaction time. Interestingly, the morphology of ZnO crystals is changed from 1D to 3D structure by controlling the feeding concentration of ZnCl2. Moreover, a concentration difference mechanism of ZnO crystal morphology evolution is proposed by monitoring the real‐time concentration of free Zn2+ ions.
Guidelines on interventions to enhance healing of foot ulcers in people with diabetes (IWGDF 2023 update)
Authors: Chen Pam , Vilorio Nalini Campillo , Dhatariya Ketan , Jeffcoate William , Lobmann Ralf , McIntosh Caroline , Piaggesi Alberto , Steinberg John , Vas Prash , Viswanathan Vijay , Wu Stephanie , Game Fran
Published: May 2023

Aims

Principles of wound management, including debridement, wound bed preparation, and newer technologies involving alternation of wound physiology to facilitate healing, are of utmost importance when attempting to heal a chronic diabetes‐related foot ulcer. However, the rising incidence and costs of diabetes‐related foot ulcer management necessitate that interventions to enhance wound healing of chronic diabetes‐related foot ulcers are supported by high‐quality evidence of efficacy and cost effectiveness when used in conjunction with established aspects of gold‐standard multidisciplinary care. This is the 2023 International Working Group on the Diabetic Foot (IWGDF) evidence‐based guideline on wound healing interventions to promote healing of foot ulcers in persons with diabetes. It serves as an update of the 2019 IWGDF guideline.

Materials and Methods

We followed the GRADE approach by devising clinical questions and important outcomes in the Patient‐Intervention‐Control‐Outcome (PICO) format, undertaking a systematic review, developing summary of judgements tables, and writing recommendations and rationale for each question. Each recommendation is based on the evidence found in the systematic review and, using the GRADE summary of judgement items, including desirable and undesirable effects, certainty of evidence, patient values, resources required, cost effectiveness, equity, feasibility, and acceptability, we formulated recommendations that were agreed by the authors and reviewed by independent experts and stakeholders.

Results

From the results of the systematic review and evidence‐to‐decision making process, we were able to make 29 separate recommendations. We made a number of conditional supportive recommendations for the use of interventions to improve healing of foot ulcers in people with diabetes. These include the use of sucrose octasulfate dressings, the use of negative pressure wound therapies for post‐operative wounds, the use of placental‐derived products, the use of the autologous leucocyte/platelet/fibrin patch, the use of topical oxygen therapy, and the use of hyperbaric oxygen. Although in all cases it was stressed that these should be used where best standard of care was not able to heal the wound alone and where resources were available for the interventions.

Conclusions

These wound healing recommendations should support improved outcomes for people with diabetes and ulcers of the foot, and we hope that widescale implementation will follow. However, although the certainty of much of the evidence on which to base the recommendations is improving, it remains poor overall. We encourage not more, but better quality trials including those with a health economic analysis, into this area.
Visualizing experimental investigation on gas–liquid replacements in a microcleat model using the reconstruction method
Authors: Chen Shaojie , Zhang Jicheng , Yin Dawei , Li Faxin , Lu Jialin , Zhu Peiyang
Published: May 2023

Cleats are the main channels for fluid transport in coal reservoirs. However, the microscale flow characteristics of both gas and water phases in primary cleats have not been fully studied as yet. Accordingly, the local morphological features of the cleat were determined using image processing technology and a transparent cleat structure model was constructed by microfluidic lithography using the multiphase fluid visualization test system. Besides, the effect of microchannel tortuosity characteristics on two‐phase flow was analyzed in this study. The results are as follows: (1) The local width of the original cleat structure of coal was strongly nonhomogeneous. The cleats showed contraction and expansion in the horizontal direction and undulating characteristics in the vertical direction. (2) The transient flow velocity fluctuated due to the structural characteristics of the primary cleat. The water‐driven gas interface showed concave and convex instability during flow, whereas the gas‐driven water interface presented a relatively stable concave surface. (3) The meniscus advanced in a symmetrical pattern in the flat channel, and the flow stagnated due to the influence of undulation points in a partially curved channel. The flow would continue only when the meniscus surface bypassed the stagnation point and reached a new equilibrium position. (4) Enhanced shearing at the gas–liquid interface increased the gas‐injection pressure, which in turn increased residual liquids in wall grooves and liquid films on the wall surface.
Rapid, repeatable landscape‐scale mapping of tree, hedgerow, and woodland habitats (THaW), using airborne LiDAR and spaceborne SAR data
Authors: Luscombe David J. , Gatis Naomi , Anderson Karen , Carless Donna , Brazier Richard E.
Published: May 2023

In the UK, tree, hedgerow, and woodland (THaW) habitats are key havens for biodiversity and support many related ecosystem services. The UK is entering a period of agricultural policy realignment with respect to natural capital and climate change, meaning that now is a critical time to evaluate the distribution, resilience, and dynamics of THaW habitats. The fine‐grained nature of habitats like hedgerows necessitates mapping of these features at relatively fine spatial resolution—and freely available public archives of airborne laser scanning (LiDAR) data at <2 m spatial resolution offer a means of doing so within UK settings. The high cost of LiDAR prohibits use for regular monitoring of THaW change, but space‐borne sensors such as Sentinel‐1 Synthetic Aperture Radar (SAR at ca. 10 m resolution) can potentially meet this need once baseline distributions are established. We address two aims in this manuscript—(1) to rapidly quantify THaW across UK landscapes using LiDAR data and (2) to monitor canopy change intra‐ and inter‐annually using SAR data. We show that workflows applied to airborne LiDAR data can deliver THaW baselines at 2 m resolution, with positional accuracy of >90%. It was also possible to combine LiDAR mapping data and Sentinel‐1 SAR data to rapidly track canopy change through time (i.e., every 3 months) using, cloud‐based processing via Google Earth Engine. The resultant toolkit is also provided as an open‐access web app. The results highlight that whilst nearly 90% of the tallest trees (above 15 m) are captured within the National Forest Inventory (NFI) database only 50% of THaW with a canopy height range of 3–15 m are recorded. Current estimates of tree distribution neglect these finer‐grained features (i.e., smaller or less contiguous THaW canopies), which we argue will account for a significant proportion of landscape THaW cover.
ASIP gene polymorphism associated with black coat and skin color in Murrah buffalo
Authors: Kumari Namita , Vasisth Rashi , Gurao Ankita , Mukesh Manishi , Vohra Vikas , Kumar Sanjay , Kataria Ranjit Singh
Published: May 2023

The melanogenesis pathway regulates pigmentation through the synergic action of various genes. We are interested in analyzing the genetic variations in the ASIP which determine eumelanin production in the dermis layer. In the present study, the ASIP gene was characterized in buffalo and 268 genetically unrelated buffaloes belonging to 10 different populations were genotyped for the non‐synonymous SNP (c.292C>T) identified in the exon 3 region of the gene using Tetra‐ARMS‐PCR. The TT genotype occurred at a higher rate in Murrah, followed by Nili Ravi, Tripura, and Paralakhemundi (42.63%, 19.30%, 3.45%, and 3.33%). These results convey the association of the black coat color of Murrah with the ASIP gene TT genotype and the lighter shades of black coat (brown and grayish‐black) color phenotype in other breeds with the CC genotype.
Synthesis and characterization of zinc oxide nanoparticles using peppermint tea (Mentha piperita) dregs extract and their photocatalytic performance
Authors: Loh Xue Lin , Ooi Zhong Xian , Teoh Yi Peng , Shuit Siew Hoong
Published: May 2023

Zinc oxide (ZnO) is a n‐type semiconductor with a wide band gap of 3.37 eV and a large excitation binding energy of 60 meV. ZnO nanoparticles (ZnO NPs) is considered as one of the best photocatalyst for the degradation of pollutants in water since it has large surface area to enhance the photocatalytic activity. This article aims to study the feasibility of using the agricultural waste of peppermint tea dregs extract with zinc nitrate hexahydrate as salt precursor to synthesis ZnO NPs through a simple, low cost, greener and environmentally friendly method. The qualitative phytochemical screening of peppermint tea dregs extract revealed the presence of flavonoids which can be served as the reducing and stabilizing agent in the synthesis of ZnO NPs. Various analytical techniques such as FTIR, UV–vis, XRD, FESEM, EDX and PSA confirmed the presence of ZnO NPs. The photocatalytic performance of the synthesized ZnO NPs showed a 95.03% degradation of crystal violet dye within 4 h of sunlight exposure.