bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chirality Inversion in Self‐Assembled Nanocomposites Directed by Curvature‐Mediated Interactions
Authors: Gong Yanjun , Cao Zhaozhen , Zhang Zongze , Liu Rongjuan , Zhang Fenghua , Wei Jingjing , Yang Zhijie 
Published: January 2022

AbstractNanoscale curvature‐dependent interactions are of paramount importance in biological systems. Here, we report that nanoscale curvature plays an important role in regulating the chirality of self‐assembled nanocomposites from chiral organic molecules and achiral nanoparticles. Specifically, we show that the supramolecular chirality of the nanocomposites markedly depends on the nanoparticle curvature, where small‐sized nanoparticles of high curvature and large‐sized nanoparticles of low curvature lead to nanocomposites with opposite chirality. Quantitative kinetic experiments and molecular dynamics simulations reveal that nanoparticle curvature plays a key role in promoting the pre‐nucleation oligomerization of chiral molecules, which consequently regulates the supramolecular chirality of the nanocomposites. We anticipate that this study will aid in rational design of an artificial cooperative system giving rise to emergent assembling phenomena that can be surprisingly rich and often cannot be understood by studying the conventional noncooperative systems.
Chiral 1,2,3‐Triazolium Salt Catalyzed Asymmetric Mono‐ and Dialkylation of 2,5‐Diketopiperazines with the Construction of Tetrasubstituted Carbon Centers
Authors: Yang Ju‐Song , Lu Ka , Li Chen‐Xiao , Zhao Zu‐Hang , Zhang Xiao‐Ming , Zhang Fu‐Min , Tu Yong‐Qiang 
Published: January 2022

AbstractNovel asymmetric mono‐ and dialkylation reactions of α‐substituted 2,5‐diketopiperazines catalyzed by new chiral spirocyclic‐amide‐derived triazolium organocatalysts have been developed, resulting in a range of enantioenriched 2,5‐diketopiperazine derivatives containing one or two tetrasubstituted carbon stereocenters. The reactions feature high yields (up to 98%), and excellent cis‐diastereo‐ and enantioselectivities (up to >20:1 dr, >99 % ee), and they provide a new asymmetric synthetic approach to important functionalized 2,5‐diketopiperazine skeletons. Furthermore, a possible reaction mechanism was proposed based on both control experiments and extensive DFT calculations.
Robust Luminescent Molecules with High‐Level Reverse Intersystem Crossing for Efficient Near Ultraviolet Organic Light‐Emitting Diodes
Authors: Chen Jinke , Liu Hao , Guo Jingjing , Wang Jianghui , Qiu Nuoling , Xiao Shu , Chi Jiajin , Yang Dezhi , Ma Dongge , Zhao Zujin , Tang Ben Zhong 
Published: January 2022

AbstractOrganic light‐emitting diodes (OLEDs) radiating near ultraviolet (NUV) light are of high importance but rarely reported due to the lack of robust organic short‐wavelength emitters. Here, we report a short π‐conjugated molecule (POPCN‐2CP) with high thermal and morphological stabilities and strong NUV photoluminescence. Its neat film exhibits an electroluminescence (EL) peak at 404 nm with a maximum external quantum efficiency (ηext,max) of 7.5 % and small efficiency roll‐off. The doped films of POPCN‐2CP in both non‐polar and polar hosts at a wide doping concentration range (10–80 wt%) achieve high‐purity NUV light (388–404 nm) and excellentηext,maxs of up to 8.2 %. The high‐level reverse intersystem crossing improves exciton utilization and accounts for the superbηext,maxs. POPCN‐2CP can also serve as an efficient host for blue fluorescence, thermally activated delayed fluorescence and phosphorescence emitters, providing excellent EL performance via Förster energy transfer.
Synthesis, structure, X‐ray photoelectron spectroscopy (XPS), and antimicrobial, anticancer, and antioxidant activities of Co (III) complexes based on the antihypertensive hydralazine
Authors: Khalil Tarek E. , Soliman Saied M. , Khalil Nessma A. , El‐Faham Ayman , Foro Sabine , El‐Dissouky Ali 
Published: January 2022

AbstractThe antimicrobial, anticancer, and antioxidant activities of four cobalt (III) complexes, [CoL2]X (X = ClO4¯ (1); OAc¯ (2), Cl¯ (3), or NO3¯ (4) with hydralazine Schiff base derivative (HL), were presented. The structure of the newly synthesized complexes 1 and 2 was confirmed utilizing FTIR, UV‐Vis, and NMR (1H and 13C) spectroscopy. In addition, single crystal X‐ray diffraction was used to approve the structure of complex 1. Based on Hirshfeld analysis, the molecular packing of 1 is controlled by short HH, OH, NH, and HC(π) interactions. The results of the X‐ray photoelectron spectroscopy (XPS) for the Co (III) complexes revealed the characteristic peaks of Co2p3/2 and Co2p1/2 with binding energy differences of 14.85–14.96 which greatly approved that the Co (III) complexes have been assembled successfully. Complex 4 (IC50 = 14.97 ± 0.59 μg/ml) has the highest cytotoxicity against lung carcinoma A‐549 cell line compared to the rest of the Co (III) complexes and the free ligand as well. Also, complex 4 has the best antioxidant activity with IC50 of 283.4 ± 12.3 μg/ml. The free ligand has broad spectrum of antibacterial and antifungal actions, while the studied Co (III) complexes have good antibacterial activity especially the chloride complex 3.
Homogeneous and heterogeneous reactions in the mixed convection flow of hybrid nanofluid over a slender cylinder
Authors: Patil Prabhugouda M. , Benawadi Sunil , Tonannavar Jagdish R. , Shanker Bandari 
Published: January 2022

AbstractThis article is about the study of homogeneous and heterogeneous reactions in the mixed convection flow of hybrid nanofluid over a moving vertical slender cylinder. It is based on the considerations of unequal diffusivity of chemical species and the numerical solutions from the nonsimilar approach. This study has found applications in many chemically reacting processes, including the processes in the biochemical systems, combustion, and catalysis. Numerically approximate solutions to a set of equations, which govern the flow, temperature, and concentrations of the chemical species with prescribed boundary constraints, are obtained by utilizing the implicit finite‐difference scheme aided by the quasi‐linearization technique. The impacts of several relevant parameters on various profiles and gradients are discussed with the aid of graphs and tables. From the results, the skin friction coefficient and rate of heat transport are pronounced to be more for hybrid nanofluid than nanofluid. The strength of homogeneous reaction on species concentration is found to be fewer than the heterogeneous reaction. The streamwise coordinate (nonsimilar variable) is more favorable to the concentration of autocatalyst than to the reactant concentration.
Phosphoglyceride‐coated polylactic acid porous microspheres and its regulation of curcumin release behavior
Authors: Shen Wen , Ning Yuanlan , Ge Xuemei , Fan Guodong , Ao Fen , Wu Shang , Mao Yueyang 
Published: January 2022

AbstractPolymer microspheres are widely used as carriers in delivering of hydrophobic or hydrophilic drugs. Surface coating of microspheres could be one of the attractive strategies to improve their properties. In this study, biodegradable polymer polylactic acid was dissolved in chloroform and non‐solvent to electrospray porous polymer microspheres. The properties of the microspheres were improved by phosphoglyceride (P‐P‐Gly) coating, and its behavior was investigated by loading with curcumin as a model drug. The morphologies of different microspheres were observed by scanning electron microscope. The results indicated that the microspheres obtained by dimethyl sulfoxide as non‐solvent could form the structure with porous characteristics. X‐ray diffraction, X‐ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy analysis revealed that P‐P‐Gly was successfully coated on the surface of the microspheres. In addition, the thermal behavior of the coated microspheres was investigated by differential scanning calorimetry. In vitro release experiments indicated that the drug‐loaded microspheres showed a very gentle release trend, which was mainly due to the P‐P‐Gly coating could not completely cover the pores of the microspheres. The P‐P‐Gly‐coated microspheres prepared in this work can be used as controlled release drug carriers with special needs.
Injection molding and shear‐induced stress simulation of poly (styrene‐ethylene‐butylene‐styrene) and polypropylene blends
Authors: Chen Yaowei , Yang Jian , He Wenjun , Liu Lilan , Niu Xinsheng , Li Chao , Xiong Mengyuan , Li Xiaoyan 
Published: January 2022

AbstractIn this article, the structure and rheological properties of poly (styrene‐ethylene‐butylene‐styrene) (SEBS) triblock copolymer blends are analyzed. The influence of polypropylene content on the three SEBS blends was discussed, the viscoelastic response and phase structure evolution during injection molding were studied. According to the capillary flow test data, the least square method is used to fit the viscosity parameters of the cross‐WLF model. The filling length of the spline was tested by adjusting the injection molding process parameters, and its accuracy was verified by comparing the filling simulation with the experimental results. Numerical simulation is used to predict the shear rate distribution of injection‐molded samples, and the shear sensitivity and residual stress of SEBS blends with different phase structures are analyzed. Based on the phase structure analysis and rheological properties, this article predicts the filling properties of triblock copolymer composites, which can be used to construct the flow‐induced structure–property relationship of complex polymer blends.
Suitably Band‐aligned MOF‐Derived Ni2P/MnO2 Heterostructure with Ni(I) Coordination Surface Sites for Self‐Coupling of Aryl Halides to Biaryls
Authors: Bhat Sajad , Wahid Malik , Banday Javid 
Published: January 2022

AbstractAn efficient photo‐redox strategy for the aryl‐aryl self‐coupling of aryl halides through a heterogeneous catalysis route has been demonstrated. A coordinatively unsaturated Ni2P surface with the enhanced photochemical property upon hetero‐structuring with δ‐MnO2 affects the organic transformation to biaryls with impressive yield and photo‐conversion efficiency. The dual‐role of the Ni2P catalyst with its participation as the catalytic active surface and the photo‐redox center distinguishes the organic transformation achieved herein with other catalytic and photocatalytic aryl‐aryl self‐coupling.
Using an intervention package with percentile schedules to increase on‐task behavior
Authors: Kwak Daniel , Najdowski Adel C. , Danielyan Svetlana 
Published: January 2022

AbstractImproving on‐task behavior can allow individuals to access more learning opportunities and is especially relevant for individuals with developmental disabilities. The current study examined the efficacy of an intervention package that used percentile schedule of reinforcement, feedback, and application of lower limits to changes in criteria to increase on‐task behaviors in children with developmental disabilities. Using a nonconcurrent multiple baseline across participants design, data revealed a functional relationship between the implementation of the intervention and an increase in the percentage of intervals that participants were on task. Overall, the participants' on‐task behavior improved from a mean of 32% during baseline to 68% during intervention, with a proportionate percentage change of 118%. Although there is no widely accepted method for shaping, using percentile schedules as part of an intervention package appears to be a promising way to shape behavior.
Rapid determination of acyclovir, its main metabolite 9‐carboxymethoxymethylguanine, ganciclovir, and penciclovir in human serum using LC–MS/MS
Authors: Ärlemalm Andreas , Helldén Anders , Karlsson Louise , Carlsson Björn 
Published: January 2022

AbstractA novel MS‐based analytical method for simultaneous analysis of the antiviral drugs acyclovir, its metabolite 9‐carboxymethoxymethylguanine, ganciclovir, and penciclovir in human serum is described. These antiviral drugs are active against herpes virus infections. Acyclovir and penciclovir are regarded as safe and effective medicines with mild side effects such as headache and gastrointestinal discomfort, and ganciclovir is regarded as more toxic and is known to cause, for example, bone marrow suppression. Acyclovir’s main metabolite 9‐carboxymethoxymethylguanine is a presumptive neurotoxin and should be monitored in patients with impaired renal function or in cases with neurotoxic symptoms. A sample was prepared using protein precipitation with 1% formic acid in methanol containing isotopically labeled internal standard. Chromatographic separation on a biphenyl column and mass spectrometric detection were performed in multiple reaction monitoring (MRM) mode on a Xevo TQ‐S micro with ESI in positive ion mode, within 3 min. Inter‐day assay accuracies for the quality controls varied between 95 and 104% and intra‐day assay between 93 and 105%. Inter‐day and intra‐day assay imprecision for the quality controls ranged between 1.4 and 4.2% and 1.7 and 6.5% respectively. The lower limit of quantification for all four substances was 0.156 μmol/L. It is an accurate and reproducible method for therapeutic drug monitoring.
Anti‐PD‐L1/TGF‐βR fusion protein (SHR‐1701) overcomes disrupted lymphocyte recovery‐induced resistance to PD‐1/PD‐L1 inhibitors in lung cancer
Authors: Cheng Bo , Ding Kaikai , Chen Pengxiang , Ji Jianxiong , Luo Tao , Guo Xiaofan , Qiu Wei , Ma Chunhong , Meng Xue , Wang Jian , Yu Jinming , Liu Yuan 
Published: January 2022

AbstractBackgroundSecond‐generation programmed cell death‐protein 1/programmed death‐ligand 1 (PD‐1/PD‐L1) inhibitors, such as bintrafusp alfa (M7824), SHR‐1701, and YM101, have been developed to simultaneously block PD‐1/PD‐L1 and transforming growth factor‐beta/transforming growth factor‐beta receptor (TGF‐β/TGF‐βR). Consequently, it is necessary to identify predictive factors of lung cancer patients who are not only resistant to PD‐1/PD‐L1 inhibitors but also sensitive to bifunctional drugs. The purpose of this study was to search for such predictors.MethodsMultivariable Cox regression was used to study the association between the clinical outcome of treatment with PD‐1/PD‐L1 inhibitors and lymphocyte recovery after lymphopenia in lung cancer patients. Murine CMT167 lung cancer cells were engineered to express the firefly luciferase gene and implanted orthotopically in the lung of syngeneic mice. Bioluminescence imaging, flow cytometry, and immunohistochemistry were employed to determine response to immunotherapy and function of tumor‐infiltrating immune cells.ResultsFor lung cancer patients treated with anti‐PD‐1/PD‐L1 antibodies, poor lymphocyte recovery was associated with a shorter progression‐free survival (PFS; P < 0.001), an accumulation of regulatory T cells (Tregs), and an elimination of CD8+ T cells in the peripheral blood. Levels of CD8+ T cells and Treg cells were also imbalanced in the tumors and peripheral immune organs of mice with poor lymphocyte recovery after chemotherapy. Moreover, these mice failed to respond to anti‐PD‐1 antibodies but remained sensitive to the anti‐PD‐L1/TGF‐βR fusion protein (SHR‐1701). Consistently, SHR‐1701 but not anti‐PD‐1 antibodies, markedly enhanced IFN‐γ production and Ki‐67 expression in peripheral CD8+ T cells from patients with impaired lymphocyte recovery.ConclusionsLung cancer patients with poor lymphocyte recovery and suffering from persistent lymphopenia after previous chemotherapy are resistant to anti‐PD‐1/PD‐L1 antibodies but might be sensitive to second‐generation agents such as SHR‐1701.
The role of mesenchymal stem cells in the occurrence, development, and therapy of hepatocellular carcinoma
Authors: Zhang Xiaoli , Li Na , Zhu Ying , Wen Wei 
Published: January 2022

AbstractHepatocellular carcinoma (HCC) is the most common type of liver malignant tumor, with high recurrence and mortality rates. Mesenchymal stem cells (MSCs) are multipotent cells that can be recruited into the tumor microenvironment (TME). What is known, TME plays a vital part in tumor progression. In recent years, accumulating studies have found that MSCs have a dual role of promotion and inhibition in the occurrence and development of HCC. In this review, we analyzed the role of MSCs in TME and summarized the relationship between MSCs and liver cancer stem cells, the molecular signaling pathway mechanisms of MSCs promoting and inhibiting HCC, and the latest research progress of MSCs in the treatment of HCC.
An Allosteric Inhibitory Potential of Triterpenes from Combretum racemosum on the Structural and Functional Dynamics of Plasmodium falciparum Lactate Dehydrogenase Binding Landscape
Authors: Oluyemi Wande M. , Samuel Babatunde B. , Adewumi Adeniyi T. , Adekunle Yemi A. , Soliman Mahmoud E. S. , Krenn Liselotte 
Published: January 2022

AbstractMultidrug resistance is a significant drawback in malaria treatment, and mutations in the active sites of the many critical antimalarial drug targets have remained challenging. Therefore, this has necessitated the global search for new drugs with new mechanisms of action. Plasmodium falciparum lactate dehydrogenase (pfLHD), a glycolytic enzyme, has emerged as a potential target for developing new drugs due to the parasite reliance on glycolysis for energy. Strong substrate‐binding is required in pfLDH enzymatic catalysis; however, there is a lack of information on small molecules’ inhibitory mechanism bound to the substrate‐binding pocket. Therefore, this study investigated a potential allosteric inhibition of pfLDH by targeting the substrate‐binding site. The structural and functional behaviour of madecassic acid (MA), the most promising among the six triterpenes bound to pfLDH, were unravelled using molecular dynamic simulations at 300 ns to gain insights into its mechanism of binding and inhibition and chloroquine as a standard drug. The docking studies identified that the substrate site has the preferred position for the compounds even in the absence of a co‐factor. The bound ligands showed comparably higher binding affinity at the substrate site than at the co‐factor site. Mechanistically, a characteristic loop implicated in the enzyme catalytic activity was identified at the substrate site. This loop accommodates key interacting residues (LYS174, MET175, LEU177 and LYS179) pivotal in the MA binding and inhibitory action. The MA‐bound pfLHD average RMSD (1.60 Å) relative to chloroquine‐bound pfLHD RMSD (2.00 Å) showed higher stability for the substrate pocket, explaining the higher binding affinity (−33.40 kcal/mol) observed in the energy calculations, indicating that MA exhibited profound inhibitory activity. The significant pfLDH loop conformational changes and the allostery substrate‐binding landscape suggested inhibiting the enzyme function, which provides an avenue for designing antimalarial compounds in the future studies of pfLDH protein as a target.
Hollow Covalent Organic Framework Cages with Zn Ion‐Implantation Promoting Photocatalytic H2 Evolution
Authors: Liu Guoyu , Pan Guodong , Dang Qiang , Li Rui , Li Liuyi , Yang Chengkai , Yu Yan 
Published: January 2022

AbstractAbstract: Covalent organic frameworks (COFs) are emerging as a class of photocatalyst for solar energy utilization. The separation of photogenerated excitons in COFs is crucial for their photocatalytic performance. Herein, we report a strategy to tune the electronic structure of COFs by implanting Zn ions within the framework to facilitate the separation and utilization of the photoinduced charges. Zn ions are incorporated within the shell of hollow COF cages (Zn@H‐TpPa) by a sacrificial template method with a formation of hollow cages. The implantation of Zn ions within the framework results in a redistribution of electron density and an increment of the polarity of the COF, as evidenced by experimental and computational analyses, and thus contributes to the separation and transport of charge carries. The Zn@H‐TpPa shows enhanced photocatalytic H2 production efficiency as compared to TpPa. The results demonstrate a new way to optimize the electronic structure of COFs for photocatalysis.
Structural Insights into Pixatimod (PG545) Inhibition of Heparanase, a Key Enzyme in Cancer and Viral Infections
Authors: Chhabra Mohit , Wilson Jennifer C. , Wu Liang , Davies Gideon J. , Gandhi Neha S. , Ferro Vito 
Published: January 2022

AbstractPixatimod (PG545), a heparan sulfate (HS) mimetic and anticancer agent currently in clinical trials, is a potent inhibitor of heparanase. Heparanase is an endo‐β‐glucuronidase that degrades HS in the extracellular matrix and basement membranes and is implicated in numerous pathological processes such as cancer and viral infections, including SARS−CoV‐2. To understand how PG545 interacts with heparanase, we firstly carried out a conformational analysis through a combination of NMR experiments and molecular modelling which showed that the reducing end β‐D‐glucose residue of PG545 adopts a distorted conformation. This was followed by docking and molecular dynamics simulations to study the interactions of PG545 with heparanase, revealing that PG545 is able to block the active site by binding in different conformations, with the cholestanol side‐chain making important hydrophobic interactions. While PG545 blocks its natural substrate HS from binding to the active site, small synthetic heparanase substrates are only partially excluded, and thus pentasaccharide or larger substrates are preferred for assaying this class of inhibitor. This study provides new insights for the design of next‐generation heparanase inhibitors and substrates.
The Effect of Fluorinated Solvents on the Physicochemical Properties, Ionic Association, and Free Volume of a Prototypical Solvate Ionic Liquid
Authors: Burba Christopher M. , Feightner Kylie , Liu Ming , Hawari Ayman 
Published: January 2022

AbstractSolvate ionic liquid (SIL) synthesis and properties depend on a delicate balancing of cation‐solvent and cation‐anion interactions to produce materials containing only cation‐solvent complexes and solvent‐separated anions. Most SILs meeting these characteristics fall within the paradigm of oligomeric ethylene oxides (e.g. glymes and glycols) and lithium salts. Targeted functionalization of solvent molecules to achieve desired properties is a relatively unexplored avenue of research. Fluorinated solvents have significantly different electric charge distributions compared to their nonfluorinated analogs. We test the impact of solvent fluorination for a SIL created from equimolar mixtures of lithium bis(trifluoromethylsulfonyl)imide (LiNTf2) and triethylene glycol (TEG), hereafter [(TEG)1Li]NTf2. In the first experiment, TEG is partially substituted with 2,2,4,4,5,5,7,7‐octafluoro‐3,6‐dioxaoctane‐1,8‐diol (FTEG). This leads to a precipitous decrease in ionic conductivity and larger quantities of ionically‐associated Li(NTf2)2− species, as detected with vibrational spectroscopy. These observations suggest FTEG does not readily coordinate Li+ ions in a manner analogous to TEG. Computational studies reinforce this conclusion. Relative complex cation stabilities are ranked as [(FTEG)1Li]+>[(TEG)1Li]+. A second experiment adds FTEG as a diluent to [(TEG)1Li]NTf2. This places FTEG and TEG in competition to coordinate a limited number of Li+ ions. The resulting mixtures exhibit conductivity enhancement over the parent SIL and minimal changes in ion speciation due to the poor Li+ binding by FTEG compared to TEG. Positron annihilation lifetime spectroscopic studies point to increased amounts of free volume upon dilution of FTEG. This likely explains the origin of the conductivity and viscosity enhancements.