bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conjugated Oligomer‐Directed Formation of Hollow Nanoparticles for Targeted Photokilling Cancer Cells under Hypoxia
Authors: Peng Rui , Luo Yufeng , Cui Qianling , Yao Chuang , Xu Wenqiang , Li Lidong 
Published: January 2022

AbstractPhotodynamic therapy (PDT) has been recognized as one powerful solution to treat cancers, but its efficacy is often impaired by the oxygen‐deficient hypoxic tumor microenvironment. Herein, conjugated oligomer‐based hollow nanoparticles are developed as efficient phototheranostic agent for targeted PDT under hypoxia. The sialic acid (SA)‐imprinted hollow nanoparticles are facilely prepared via a nanoprecipitation method using a conjugated oligomer as photosensitizer and an amphiphilic polymer as matrix. The strong intra‐ and inter‐molecular π–π stacking interactions of the conjugated oligomer direct the self‐assembly and formation of hollow nanostructure. Triggered by 660 nm laser, the nanoparticles exhibit prominent reactive oxygen species (ROS) generation both in water and cellular medium, which are specifically determined as singlet oxygen (1O2) and superoxide radical (O2–•) under normoxia (20% O2) while mainly O2–• under hypoxia (1% O2). Moreover, the feature of SA‐imprinted surface makes these nanoparticles capable of selectively targeting and being internalized into SA over‐expressed cancer cells, and their efficient PDT behaviors in vitro are also demonstrated even under severely hypoxic environment. Thus, the work provides a promising photosensitizer candidate for targeted PDT in hypoxic tumor.
Regioselective N‐Functionalization of Tautomerizable Heterocycles through Methyl Trifluoromethanesulfonate‐Catalyzed Substitution of Alcohols and Alkyl Group Migrations
Authors: Duari Surajit , Biswas Subrata , Roy Arnab , Maity Srabani , Mishra Abhishek Kumar , de Souza Aguinaldo R. , Elsharif Asma M. , Morgon Nelson H. , Biswas Srijit 
Published: January 2022

AbstractA catalytic synthetic strategy has been developed combining two protocols, such as, direct nucleophilic substitution of alcohols followed by X‐ to N‐ alkyl group migration (X=O, S) to access N‐functionalized benzoxazolones, benzothiazolethiones, indolinone, benzoimidazolethiones, and pyridinones derivatives. Methyl trifluoromethanesulfonate (MeOTf) was found to catalyze the reaction, which revealed the catalytic property of MeOTf. A mechanism was established through experiments as well as DFT calculations wherein the −OH group of alcohols were converted to the corresponding −OMe groups and in situ generated TfOH. The −OMe groups produced underwent TfOH catalyzed −X alkylation (X=O, S) of the heterocycles followed by −X‐ to −N‐alkyl group migrations in a single step.magnified image
2‐(Alkynyl)anilines and Derivatives — Versatile Reagents for Heterocyclic Synthesis
Authors: Festa Alexey A. , Raspertov Pavel V. , Voskressensky Leonid G. 
Published: January 2022

AbstractThe transformations of 2‐alkynylanilines and their derivatives into heterocycles are surveyed. Depending on the substituents, catalysts, and reaction conditions, these substrates can be converted into indoles, quinolines, indolines, oxindoles, indoxiles, various polycyclic compounds, etc. This review aims to generalize and assess the patterns of reactivity, selectivity, and applicability of 2‐(alkynyl)anilines in heterocyclic chemistry. The review is divided into sections in accordance with the produced heterocycle. In summary, the title substrates are capable of cyclizing not only into five‐ and six‐membered rings, but also to produce seven‐ and even eight‐membered ring systems. The preparation of 2‐(alkynyl)anilines is not covered.magnified image
Mechanochemical Pretreatment for Waste‐Free Conversion of Bamboo to Simple Sugars: Utilization of Available Resources for Developing Economies
Authors: Ekwe Nneka B. , Tyufekchiev Maksim V. , Salifu Ali A. , Tompsett Geoffrey A. , LeClerc Heather O. , Belden Elizabeth R. , Onche Emmanuel O. , Ates Ayten , Schmidt‐Rohr Klaus , Yuan Shichen , Zheng Zhaoxi , Soboyejo Winston O. , Timko Michael T. 
Published: January 2022

AbstractIn this work, mechanochemical pretreatment of Bambusa vulgaris is evaluated for waste‐free production of renewable sugars for subsequent fermentation. After a 60 min mechanochemical pretreatment followed by enzyme hydrolysis at 50 °C, 62% of the available carbohydrate can be recovered as fermentable sugars, primarily in the form of glucose and xylose. Structural and chemical analysis finds that mechanochemical pretreatment increases accessible surface area and amorphizes the crystalline cellulose present in bamboo, both of which increase reactivity. The experimental results are then used for a systems‐level analysis of ethanol production in Nigeria. The energy required for mechanochemical pretreatment is estimated to be 0.5–5.6 MJ per kg of bamboo; this energy can be provided by solar power, while still satisfying existing needs for stationary power. Ethanol production on marginal land alone is projected to be sufficient to replace nearly 80% of Nigeria's current gasoline usage while reserving sufficient land area for solar power generation to meet current electricity needs, meaning that bamboo cultivation followed by mechanochemical pretreatment can play an important role for utilizing locally available resources without generation of new chemical wastes.
A segment probability method for calculating the molecular weight distributions of linear polycondensates in a continuous reactor
Authors: Chang Cheng , Feng Lian‐Fang , Gu Xue‐Ping , Zhang Cai‐Liang , Chen Xi , Hu Guo‐Hua 
Published: January 2022

AbstractThe molecular weight distribution (MWD) of polymers is a target of the optimization and control of industrial polymerization processes, as it dictates the processability and properties of polymers. A method, named as segment probability method, is developed to calculate the MWD of polycondensates produced by monomers of types A2 and B2 in a continuous reactor. It considers a growing chain as being composed of A and B segments in the middle of the chain and two terminal segments at the chain ends. It calculates the propagation probabilities of these different types of segments upon taking into account both the polycondensation and side reaction kinetics as well as the residence time distribution of the continuous reactor. The method is validated by poly(butylene terephthalate) (PBT) obtained from an industrial polymerization process composed of a continuous esterification reactor. The MWDs of the PBT calculated by this method are in agreement with those measured by size exclusion chromatography with mean square errors less than 10%.
Multi‐omics differential gene regulatory network inference for lung adenocarcinoma tumor progression biomarker discovery
Authors: Tong Yi‐Fan , He Qi‐En , Zhu Jun‐Xuan , Ding En‐Ci , Song Kai 
Published: January 2022

AbstractA systematic method was proposed to infer differential gene regulatory networks (GRNs) among lung adenocarcinoma (LUAD) samples at different stages by integrating multi‐omics data to uncover significant network features and to identify tumor progression (TP) biomarker genes. The mRNA expressions, copy number variations, and DNA methylations of two independent LUAD cohorts (TCGA and SPORE) at stages I, II, and III were used, respectively. As results, the transition from normal to early onset was showed to be critical to reveal the pathogenesis of LUAD; 61 genes were identified as TP‐related biomarkers, including two types of microRNAs ofABLIM2andZFAS1. These identified biomarkers may set light on the underlying mechanism of LUAD TP and may serve as potential drug targets for new treatments. Moreover, our study provides a general framework for TP biomarker identification for other types of cancer, which may improve the mechanism research for cancer development.
Fetal presentation of chondrodysplasia with joint dislocations, GPAPP type, caused by novel biallelic IMPAD1 variants
Authors: Venkatapuram Vijaya Sree , Aggarwal Shagun , Kulkarni Aditya Deepak , Vineeth Venugopal Satidevi , Bhikaji Dalal Ashwin , Bhat Venkatraman , Kiran Lavanya , Patil Siddaramappa Jagdish 
Published: January 2022

AbstractBiallelic IMPAD1 pathogenic variants leads to deficiency of GPAPP (Golgi 3‐prime phosphoadenosine 5‐prime phosphate 3‐prime phosphatase) protein and clinically causes chondrodysplasia, which is characterized by short stature with short limbs, craniofacial malformations, cleft palate, hand and foot anomalies, and various radiographic skeletal manifestations. Here we describe prenatal presentation of GPAPP deficiency caused by novel biallelic pathogenic variants, 2 base pair duplication in exon 2 of IMAPD1 gene in a patient of Asian‐Indian origin. Further we report on diagnostic clues of prenatal presentation of GPAPP deficiency through ultrasonography, fetal MRI, and postmortem findings. We also provide evidence of pathophysiology of underlying GPAPP deficiency in the form of disorganization and dysplastic chondrocytes and reduced sulfation of glycoproteins through histopathology of cartilage similar to that described in mice IMPAD1 homozygous mutant model.
Influence of Catalyst Reduction Temperature on Autogenous Glycerol Hydrogenolysis over NiAl Catalyst
Authors: Pandya Rajan , Mane Rasika , Rode Chandrashekhar 
Published: January 2022

AbstractAutogenous glycerol hydrogenolysis to 1,2‐propanediol by aqueous phase reforming (APR) was investigated over supported nickel catalysts. Effect of reduction temperature on physico‐chemical properties of catalysts played a significant role in tuning conversion and product selectivities. The formation of nickel aluminate (NiAl2O4) spinel phase during catalyst reduction led to rearrangement of Ni species to obtain small and stable Ni particles. The catalyst activation temperature alters the extent of reduction of multivalent Ni species (Ni0, Ni+2/+3) which facilitated glycerol dehydration and hydrogenation while suppressing C−C cleavage and thus avoiding undesirable side products. Additionally, presence of moderate BrØnsted/Lewis acid ratio of the catalyst promoted higher 1,2‐PDO selectivity. In‐situ glycerol hydrogenolysis involves glycerol dehydration to acetol with simultaneous reforming to H2 and CO2 and this hydrogen converts acetol to 1,2‐PDO.
Multicolour Fluorescence Based on Excitation‐Dependent Electron Transfer Processes in o‐Carborane Dyads
Authors: Yang Heyi , Liu Haichao , Shen Yunxia , Zhang Shi‐tong , Zhang Qing , Song Qingbao , Lv Chunyan , Zhang Cheng , Yang Bing , Ma Yuguang , Zhang Yujian 
Published: January 2022

AbstractOrganic materials with excitation wavelength‐dependent (Ex‐de) emission are highly attractive for anticounterfeiting, optoelectronics and bioassay applications; however, the realization of Ex‐de fluorescence, independent of aggregation states, remains a challenge. We herein report a photoinduced electron transfer (PeT) strategy to design Ex‐de fluorescence materials by manipulating the relaxation pathways of multiple excited states. As expected, the o‐carborane dyad presents a clear Ex‐de fluorescence colour in the aggregated states, resulting from the tunable relative intensity of the dual‐fluorescence spectra. Taking TP[1]B as an example, the amorphous powders emitted bright blue‐violet, white and yellow colours under 390 nm, 365 nm and 254 nm UV illumination, respectively. Importantly, multicolour, flexible and transparent films as well as an anticounterfeiting application using this o‐carborane dyad are demonstrated.
Deeper Insight into the Role of Organic Ammonium Cations in Reducing Surface Defects of the Perovskite Film
Authors: Jiang Xiaoqing , Zhang Jiafeng , Liu Xiaotao , Wang Ziyuan , Guo Xin , Li Can 
Published: January 2022

AbstractOrganic ammonium salts (OASs) have been widely used to passivate perovskite defects. The passivation mechanism is usually attributed to coordination of OASs with unpaired lead or halide ions, yet ignoring their interaction with excess PbI2 on the perovskite film. Herein, we demonstrate that OASs not only passivate defects by themselves, but also redistribute excess aggregated PbI2 into a discontinuous layer, augmenting its passivation effect. Moreover, alkyl OAS is more powerful to disperse PbI2 than a F‐containing one, leading to better passivation and device efficiency because F atoms restrict the intercalation of OAS into PbI2 layers. Inspired by this mechanism, exfoliated PbI2 nanosheets are adopted to provide better dispersity of PbI2, further boosting the efficiency to 23.14 %. Our finding offers a distinctive understanding of the role of OASs in reducing perovskite defects, and a route to choosing an OAS passivator by considering substitution effects rather than by trial and error.
Photoswitchable Serotonins for Optical Control of the 5‐HT2A Receptor**
Authors: Morstein Johannes , Romano Giovanna , Hetzler Belinda E. , Plante Ambrose , Haake Caleb , Levitz Joshua , Trauner Dirk 
Published: January 2022

AbstractSerotonin receptors play central roles in neuromodulation and are critical drug targets for psychiatric disorders. Optical control of serotonin receptor subtypes has the potential to greatly enhance our understanding of the spatiotemporal dynamics of receptor function. While other neuromodulatory receptors have been successfully rendered photoswitchable, reversible photocontrol of serotonin receptors has not been achieved, representing a major gap in GPCR photopharmacology. Herein, we develop the first tools that allow for such control. Azo5HT‐2 shows light‐dependent 5‐HT2AR agonism, with greater activity in the cis‐form. Based on docking and test compound analysis, we also develop photoswitchable orthogonal, remotely‐tethered ligands (PORTLs). These BG‐Azo5HTs provide rapid, reversible, and repeatable optical control following conjugation to SNAP‐tagged 5‐HT2AR. Overall, this study provides a foundation for the broad extension of photopharmacology to the serotonin receptor family.
Metal–Organic Frameworks with Zero and Low‐Valent Metal Nodes Connected by Tetratopic Phosphine Ligands
Authors: Sikma R. Eric , Cohen Seth M. 
Published: January 2022

AbstractMetal–organic frameworks (MOFs) constructed with M0 nodes are attractive targets due to the reactivity of these low‐valent metals, but examples of these MOFs remain exceedingly rare. The rational design of three‐dimensional MOFs with Pd0 and Pt0 nodes using tetratopic phosphine ligands is reported. Five new MOFs have been synthesized by systematic variation of the phosphine ligands and metal precursors employed, and these represent the first examples of MOFs constructed using phosphine–metal bonds as the sole structural component. The MOFs display solid‐state luminescence, with emission maxima that are significantly red‐shifted compared to Pd(PPh3)4. In addition, a RhI low‐valent coordination solid based on the same linker design is reported, which displays solid‐state luminescence that is not observed for the molecular analogue.
Catalytic Transformation of PET and CO2 into High‐Value Chemicals
Authors: Li Yinwen , Wang Meng , Liu Xingwu , Hu Chaoquan , Xiao Dequan , Ma Ding 
Published: January 2022

AbstractPolyethylene terephthalate (PET) and CO2, two chemical wastes that urgently need to be transformed in the environment, are converted simultaneously in a one‐pot catalytic process through the synergistic coupling of three reactions: CO2 hydrogenation, PET methanolysis and dimethyl terephthalate (DMT) hydrogenation. More interestingly, the chemical equilibria of both reactions were shifted forward due to a revealed dual‐promotion effect, leading to significantly enhanced PET depolymerization. The overall methanol yield from CO2 hydrogenation exceeded the original thermodynamic equilibrium limit since the methanol was in situ consumed in the PET methanolysis. The degradation of PET by a stoichiometric ratio of methanol was significantly enhanced because the primary product, DMT was hydrogenated to dimethyl cyclohexanedicarboxylate (DMCD) or p‐xylene (PX). This synergistic catalytic process provides an effective way to simultaneously recycle two wastes, polyesters and CO2, for producing high‐value chemicals.
Citing criteria and its effects on researcher's intention to cite: A mixed‐method study
Authors: Xie Juan , Lu Hongru , Kang Lele , Cheng Ying 
Published: January 2022

AbstractThis study explored users' criteria for citation decisions and investigated the effects on users' intention to cite using a mixed‐method approach. A qualitative study was conducted first, where 16 citing criteria were identified based on interviews and inductive analysis. The findings were then used to develop hypotheses and extend the information adoption model. A questionnaire was designed to collect data from users in Chinese universities to test the research model. The findings indicated that pleasure, topicality, and functionality significantly increased users' perceived information usefulness, while familiarity and accessibility significantly enhanced users' perceived ease of use. Information usefulness and information ease of use further contributed to users' intention to cite with adjusted R2 equaling 44.6%. It is also found that perceived academic quality based on 5 antecedents (i.e., reliability, comprehensiveness, novelty, author credibility, and source reputation) significantly increased users' pleasure. Implications and limitations were provided.
New delay‐dependent H∞ state estimator for static neural networks with bounded and unbounded time delays
Authors: Liu Guoquan , Luo Chaomin , Zhou Shumin , Li Yuezhong , Luo Xianxi 
Published: January 2022

AbstractAn H∞ estimation issue for static neural networks (SNNs) is discussed by the research, and the SNN model is improved from the following two aspects: (1) The SNNs contains both bounded and unbounded delays. (2) The nonlinear activation function is bounded and belongs to an interval. Through the construction of the novel Lyapunov–Krasovskii functional (LKF), the state estimator is established. It is also pointed that a gain matrix is acquired by the linear matrix inequality (LMI). Numerical experiments indicate that the method put forward in this study is valid. In addition, the obtained results are characterized by effectiveness and correctness.
Grey‐prediction‐based double model predictive control strategy for the speed and current control of permanent magnet synchronous motor
Authors: Pan Hongguang , Huang Xinyi , Guan Penglin , Liu Shulin 
Published: January 2022

AbstractTo solve the problems of slow response speed of the permanent magnet synchronous motor (PMSM) system when the external disturbance occurs and the poor disturbance rejection performance, a double model predictive control (MPC) strategy for PMSM to control speed and current is proposed in this paper. Further, in order to improve the dynamic performance and disturbance rejection performance of PMSM control system, a grey prediction is introduced, and then a grey‐prediction‐based double MPC strategy is proposed. To be specific, firstly, the mathematical model of PMSM is established under thedqcoordinate system, and the traditional control strategy (outer speed loop PI controller and inner current loop deadbeat prediction controller) is elaborated. Secondly, we propose the double MPC strategy where MPC controller is used in the outer speed loop and deadbeat prediction controller is used in the inner current loop. Finally, the grey‐prediction‐based double MPC strategy is proposed where MPC is combined with grey prediction to improve the dynamic performance in the inner current loop. By comparing the traditional control strategy with the double MPC and the grey‐prediction‐based double MPC strategy, the simulation results show that the double MPC and the grey‐prediction‐based double MPC system have no overshoot and the grey‐prediction‐based double MPC system has better steady‐state performance, faster dynamic response and stronger disturbance rejection performance, which proves the effectiveness of the proposed strategy.
The burden of primary liver cancer caused by specific etiologies from 1990 to 2019 at the global, regional, and national levels
Authors: Yang Jianqing , Pan Guangdong , Guan Linjing , Liu Zhipeng , Wu Yongrong , Liu Zhen , Lu Wuchang , Li Shuai , Xu Honglai , Ouyang Guoqing 
Published: January 2022

AbstractBackgroundLiver cancer is one of the most common cancers worldwide. We aimed to report the burden of liver cancer at the global, regional, and national levels in 204 countries from 1990 to 2019, stratified by etiology, sex, age, and sociodemographic index (SDI).MethodsData of mortality, incidence, and disability‐adjusted life years (DALYs) of liver cancer and its etiology were available from the Global Burden of Diseases, Injuries, and Risk Factors (GBD) Study 2019. The trends in the liver cancer burden were assessed by the annual percentage change. All estimates are presented as numbers and age‐standardized rates (ASRs) per 100,000 population, with uncertainty intervals (UIs).ResultsGlobally, 484,577 (95% UI 444,091–525,798) mortalities, 534,364 (486,550–588,639) incident cases, and 12,528,422 (11,400,671–13,687,675) disability‐adjusted life years (DALYs) due to liver cancer occurred in 2019. The ASRs were 5.95 (5.44–6.44), 6.51 (5.95–7.16), and 151.08 (137.53–164.8) per 100,000 population for the mortalities, incidences, and DALYs, respectively. From 1990 to 2019, the numbers increased, whereas the ASRs decreased. Hepatitis B and Hepatitis C are the major causes of liver cancer mortality. The liver cancer mortality in 2019 increased with age, peaking at 65–69 and 70–74 age group in males and females, respectively, and the number was higher in males than in females. Generally, there were nonlinear associations between the ASR and SDIs values at the regional and national levels. China had the highest numbers of mortalities, incident cases, and DALYs, whereas Mongolia has the highest ASR in 2019.ConclusionLiver cancer remains a major public health issue worldwide, but etiological and geographical variations exist. It is necessary to increase awareness of the population regarding liver cancer, its etiologies and the importance of early detection, and diagnosis and treatment.
Sandacrabins – Structurally Unique Antiviral RNA Polymerase Inhibitors from a Rare Myxobacterium**
Authors: Bader Chantal D. , Panter Fabian , Garcia Ronald , Tchesnokov Egor P. , Haid Sibylle , Walt Christine , Spröer Cathrin , Kiefer Alexander F. , Götte Matthias , Overmann Jörg , Pietschmann Thomas , Müller Rolf 
Published: January 2022

AbstractStructure elucidation and total synthesis of five unprecedented terpenoid‐alkaloids, the sandacrabins, are reported, alongside with the first description of their producing organism Sandaracinus defensii MSr10575, which expands the Sandaracineae family by only its second member. The genome sequence of S. defensii as presented in this study was utilized to identify enzymes responsible for sandacrabin formation, whereby dimethylbenzimidazol, deriving from cobalamin biosynthesis, was identified as key intermediate. Biological activity profiling revealed that all sandacrabins except congener A exhibit potent antiviral activity against the human pathogenic coronavirus HCoV229E in the three digit nanomolar range. Investigation of the underlying mode of action discloses that the sandacrabins inhibit the SARS‐CoV‐2 RNA‐dependent RNA polymerase complex, highlighting them as structurally distinct non‐nucleoside RNA synthesis inhibitors. The observed segregation between cell toxicity at higher concentrations and viral inhibition opens the possibility for their medicinal chemistry optimization towards selective inhibitors.