bluuebunny/crossref_metadata_2025 huggingface dataset:
Protein loops with multiple meta‐stable conformations: A challenge for sampling and scoring methods
Authors: Barozet Amélie , Bianciotto Marc , Vaisset Marc , Siméon Thierry , Minoux Hervé , Cortés Juan
Published: September 2020

Flexible regions in proteins, such as loops, cannot be represented by a single conformation. Instead, conformational ensembles are needed to provide a more global picture. In this context, identifying statistically meaningful conformations within an ensemble generated by loop sampling techniques remains an open problem. The difficulty is primarily related to the lack of structural data about these flexible regions. With the majority of structural data coming from x‐ray crystallography and ignoring plasticity, the conception and evaluation of loop scoring methods is challenging. In this work, we compare the performance of various scoring methods on a set of eight protein loops that are known to be flexible. The ability of each method to identify and select all of the known conformations is assessed, and the underlying energy landscapes are produced and projected to visualize the qualitative differences obtained when using the methods. Statistical potentials are found to provide considerable reliability despite their being designed to tradeoff accuracy for lower computational cost. On a large pool of loop models, they are capable of filtering out statistically improbable states while retaining those that resemble known (and thus likely) conformations. However, computationally expensive methods are still required for more precise assessment and structural refinement. The results also highlight the importance of employing several scaffolds for the protein, due to the high influence of small structural rearrangements in the rest of the protein over the modeled energy landscape for the loop.
A two‐dimensional multiwell cell culture method for the production of CYP3A4‐expressing hepatocyte‐like cells from HepaRG cells
Authors: Ooeda Keiko , Kubiura‐Ichimaru Musashi , Tsuji Saori , Okuyama Shota , Yamashita Mao , Mine Akari , Kawamura Fumihiko , Ueyama Takafumi , Tada Masako
Published: September 2020

Cytochrome P450 enzymes (CYP) function in drug metabolism in the liver. To evaluate numerous drug candidates, a high‐content screening (HCS) system with hepatocyte‐like cells (HLCs) that can replace adult human hepatocytes is required. Human hepatocellular carcinoma HepaRG is the only cell line capable of providing HLCs with high CYP3A4 expression comparable to that in adult hepatocytes after cell differentiation. The aim of this study was to design an ideal multiwell culture system for HLCs using transgenic HepaRG cells expressing the EGFP coding an enhanced green fluorescent protein under CYP3A4 transcriptional regulation. HLCs were matured on five different types of 96‐well black plates. Culturing HLCs on glass‐bottom Optical CVG plates significantly promoted cell maturation and increased metabolic activity by twofold under two‐dimensional (2D) culture conditions, and these features were enhanced by 2% collagen coating. Three plates for three‐dimensional (3D) cell cultures with a gas‐exchangeable fabric or dimethylpolysiloxane membrane bottom formed multiple round colonies, whereas they were ineffective for CYP3A4 expression. Under optimized conditions presented here, HLCs lost responsiveness to nuclear receptor‐mediated transcriptional induction of CYP3A4, suggesting that CYP3A4 transcription has already been fully upregulated. Therefore, HepaRG‐derived HLCs will provide an alternative to human hepatocytes with high levels of CYP3A4 enzyme activity even under 2D culture conditions. This will improve a variety of drug screening methods.
The mediating and moderating role of neighbourhoods and regions on second‐generation immigrant youths' school‐to‐work transitions in the Netherlands
Authors: Wessling Katarina , Meng Christoph
Published: September 2020

Contexts in which people live such as neighbourhoods, cities or regions influence individuals. However, research analysing effects of different contexts simultaneously is limited. Our paper's focus is to examine the interrelation between regional and neighbourhood conditions and their influence on school‐to‐work transitions. We investigate the process of transitioning from vocational training to employment, with a specific focus on adolescents from non‐Western immigrant origin. We link Dutch survey data on almost 15,000 graduates with spatial information from Statistics Netherlands and compare results across multilevel linear probability models. Overall, we find employment prospects to be reduced in neighbourhoods and regions that are socioeconomically unfavourable. However, neighbourhood influences diminish or even disappear once accounted for the region. Deprived conditions in urban regions are particularly detrimental for adolescents of immigrant descent. However, a high share of coethnics in the neighbourhood reduces the unemployment risk of second‐generation non‐Western minorities in deprived urban regions. This finding stresses the relevance of immigrants' neighbourhood networks for education and employment prospects.
The safety and efficacy of Momordica charantia L. in animal models of type 2 diabetes mellitus: A systematic review and meta‐analysis
Authors: Peter Emanuel L. , Nagendrappa Prakash B. , Kaligirwa Anita , Ogwang Patrick Engeu , Sesaazi Crispin Duncan
Published: September 2020

Type 2 diabetes mellitus is a chronic hyperglycemic condition due to progressively impaired glucose regulation. Momordica charantia L. could potentially improve hyperglycemia because its fruit extracts can alleviate insulin resistance, beta‐cell dysfunction, and increase serum insulin level. We evaluated the effect of M. charantia L. in comparison with a vehicle on glycemic control in animal models of type 2 diabetes mellitus. MEDLINE, Web of Science, Scopus, and CINAHL databases were searched without language restriction through April 2019. About 66 studies involving 1861 animals that examined the effect of M. charantia L. on type 2 diabetes mellitus were included. Fruits and seed extracts reduced fasting plasma glucose (FPG) and glycosylated hemoglobin A1c in comparison to vehicle control: (42 studies, 815 animals; SMD, −6.86 [95% CI; −7.95, −5.77], 3 studies, 59 animals; SMD; −7.76 [95% CI; −12.50, −3.01]) respectively. Also, the extracts have hepato‐renal protective effects at varying doses and duration of administration. Despite the observed significant glycemic control effect, poor methodological quality calls for future researches to focus on standardizing extract based on chemical markers and adopt measures to improve the quality of preclinical studies such as sample size calculation, randomization, and blinding.
Calibration of Green‐Ampt wetting front suction for ponding and non‐ponding infiltration scenarios
Authors: Pereira Caroline Andrade , Gubiani Paulo Ivonir , de Jong Van Lier Quirijn
Published: September 2020

Mathematical formulations for layered soil profiles and corresponding parameterization to improve performance of the Green‐Ampt model (GA) have not always shown accurate. We evaluated GA maintaining its assumption of saturated flow but calibrating the effective matric suction at the wetting front (hf) by damping the initial matric suction (hi). The proposition was evaluated comparing cumulative infiltration simulated by GA to that simulated by Hydrus‐1D for five soils from three texture classes, three initial matric suctions, and five 24‐h water supply regimes. For each case, GA was run with a decreasing series of 20 values of hf from the initial matric suction (10, 100, or 1000 cm) to values near 1 cm. To minimize the relative error (RE) between cumulative infiltration simulated by GA and Hydrus‐1D for the 24‐h period we found the required damping of hf to be dependent on soil type, water supply regime and initial matric suction, the latter being the most important factor. The calibration of hf was efficient to approach GA predictions to numerical Hydrus‐1D simulations, even for cases with alternating ponding and non‐ponding conditions. Results suggest a large reduction of wetting front matric suction hf may be necessary to approach cumulative infiltration predicted by GA to corresponding Hydrus‐1D predictions, especially during rainfall events that do not imply in continuous ponding. Taking hf somewhere between 1 and 3 cm, values of RE of cumulative infiltration during the first 24 h were below 10% for all cases, independent of soil type, rainfall characteristics or initial water content.
Linear and NLO Properties of Functional Group and Position Isomers of Azo and Azomethine: Comparative Photophysical‐Electrochemical Properties, Z‐Scan and DFT Studies
Authors: Mishra Virendra R. , Ghanavatkar Chaitannya W. , Sharma Suryapratap , Premarani Aswathy , Mathew Elizabeth , Joe Isaac H. , Sekar Nagaiyan
Published: September 2020

Functional group and position isomers of azo and azomethine were selected to investigate their effect on linear and NLO properties. The azo and azomethine analogs show absorption maxima in the range 460–500 nm and 375–435 nm respectively. They are emissive in green, orange to the deep red region with a large Stokes shift of 100–200 nm. When we compared azo and azomethine chromophores i. e. functional group isomers, azo chromophore shows a bathochromic shift of 50–103 nm, while in case of position isomers azo and azomethine having larger conjugation effect i. e. VA‐2 and VI‐2 show a more bathochromic shift of 28 nm and 42 nm than the corresponding analogs VA‐1 and VI‐1, which show respectively 466 nm and 379 nm. Band gaps evaluated by electrochemical method and DFT method are correlated with the bathochromic shift in absorption maxima. The dyes are thermally stable (up to 280 °C). Open and closed aperture Z‐scan techniques were used to evaluate the third order non‐linear optical (NLO) parameters ‐ nonlinear absorptive coefficient (β), nonlinear refractive index (η2), and third order non‐linear optical susceptibility (χ (3)). NLO properties were theoretically calculated by using DFT method with six different functionals. Mean absolute error (MAE) and standard deviation (SD) were evaluated to get more insight into theoretical calculation. With the set of calculated data points, MAE and SD calculated to check performance of the DFT functional. Different functionals were used to evaluate vertical excitation values and compared it with experimental absorption maxima.
Solid‐State Synthesis of Silver Nanoparticles and Their Catalytic Application in Methylene Blue Reduction
Authors: Veljović Djordje N. , Gurešić Dejan M. , Jokić Anja B. , Vasić Vesna M. , Laban Bojana B.
Published: September 2020

The silver nanoparticles (Ag NPs) were successfully synthesized by a facile solid‐state chemical method. Ag NPs were obtained by a mechanochemical reaction between silver nitrate and sodium citrate, with the constant stirring and heating of reactants. The size and morphology characterization of NPs powder was performed by scanning electron microscopy. The obtained NPs were spherical with a 36 nm average particle size diameter. UV‐Vis spectroscopy, dynamic light scattering, and zeta potential measurements were used in order to characterize the surface plasmon band position in colloid dispersion and the NPs charges. Obtained NPs were utilized as a catalyst in the process of methylene blue (MB) reduction in the presence of sodium‐borohydride. Kinetic measurements of uncatalyzed and catalyzed reduction were carried out using the stopped‐flow technique, keeping the concentration of reactant constant. Mechanism of MB reduction in the presence of catalyst Ag NPs is elucidated as a consecutive two first‐order reactions. The results of these studies support the hypothesis that NPs participated in electron transfer.
CTAB‐PLGA Curcumin Nanoparticles: Preparation, Biophysical Characterization and Their Enhanced Antifungal Activity against Phytopathogenic Fungus Pythium ultimum
Authors: Khatua Ashapurna , Prasad Abhinav , Priyadarshini Eepsita , Virmani Ishita , Ghosh llora , Paul Bernard , Meena Ramovatar , Barabadi Hamed , Patel Amiya Kumar , Saravanan Muthupandian
Published: September 2020

In the current study, we utilized application of nanotechnological advancements to synthesize positively charged curcumin nanoparticles (CurNPs). In CurNPs, curcumin (Cur) was encapsulated by a stabilizer, polymer poly(lactic‐co‐glycolic acid) (PLGA) and its surface charge was modified by cationic surfactant cethyltrimetylammonium bromide (CTAB). Characterization methods involving UV‐visible spectroscopy, X‐ray diffraction (XRD), transmission electron microscopy (TEM) and dynamic light scattering (DLS) were employed to confirm their synthesis. Then, we used CurNPs to investigate their potential as fungicidal agents in vitro and the underlying mechanisms, as compared to free Cur in the two fungal strains SR1 and BP1120 of a destructive plant pathogen Pythium ultimum var. ultimum. The fungicidal activity of CurNPs were studied by several methods which resulted in comparatively more pronounced antifungal activity in BP1120 than SR1. Broth dilution and well diffusion assay revealed minimum inhibitory concentration (MIC80) for CurNPs to be 52.57 μg/mL and 44.67 μg/mL and an increase in zone of inhibition (ZOI) by 5.4 and 6.3 fold of Cur at 15 μg/mL of CurNPs in SR1 and BP1120, respectively. Study of growth curve showed prolonged lag phase, delayed and short log phase, early and prolonged stationary phase and early decline phase after CurNPs exposure. Toxicity of CurNPs in SR1 and BP1120 strains of P. ultimum was attributed to the enhancement in intracellular reactive oxygen species (ROS) generation and fall in mitochondrial membrane potential (MMP) as revealed by spectrofluorometric assay. Taken together, these CurNPs were confirmed as a novel and very potent fungicidal agents against P. ultimum var. ultimum with a great promise of controlling and treating other microbial infections.
A New Squaraine‐Linked Triazinyl‐Based Covalent Organic Frameworks: Preparation, Characterization and Application for Sensitive and Selective Determination of Fe3+ Cations
Authors: Xue Rui , Gou Hao , Zheng Yanping , Zhang Li , Liu Yinsheng , Rao Honghong , Zhao Guohu
Published: September 2020

A new triazinyl‐based covalent organic frameworks(COFs) linked by squaraine(ST‐COF‐1) was synthesized via condensation of squaric acid (SA) and 1,3,5‐triazine‐2,4,6‐triamine (Melamine, MA). The BET surface area of ST‐COF‐1 was calculated as 484.12 m2 g−1. The suspension of this material will emit strong blue fluorescence under the irradiation of 365 nm ultraviolet lamp. Strong quenching effects of Fe3+ on the fluorescence of the COFs allowed selective chemosensing for Fe3+ cation. In addition, some nitro aromatic compounds also cause strong fluorescence quenching, which proves that this material can also be used for the qualitative detection of nitro aromatic compounds.
Flexible Solid PANI Fiber Networks/Ni‐MOF@CC Electrodes for High‐Performance Capacitors: Synthesis and Stability Study
Authors: Dong Shibo , Wang Qiguan , Zhang Wenzhi , Chen Jian , Wang Sumin
Published: September 2020

In this work, the nickel‐based metal organic framework (Ni‐MOF) is attached to the conductive carbon cloth (CC) by using a hydrothermal reaction. In order to make MOFs strongly interacted with CC, polymeric molecules of polyaniline (PANI) are deposited on Ni‐MOF@CC employing an in–situ polymerization method. The PANI shows a three‐dimensional fiber‐network morphology. Due to the improved electrical conductivity and the porous networks, the electrochemistry property of the obtained flexible PANI/Ni‐MOF@CC is greatly enhanced compared with Ni‐MOF@CC. The specific capacitance of PANI/Ni‐MOF@CC reaches 109 F cm−2 (573 F g−1). The optimum energy density of PANI/Ni‐MOF@CC at 0.1 A cm−2 can be 7 mWh cm−2 with power density of 70 mW cm−2. Because the fiber networks of PANI on MOF enhances the interactions between MOF and CC, the PANI/Ni‐MOF@CC shows high stability of 95 % capacitance retention after 5000 charge‐discharge cycling.
Simple Iron(III) Complex Based Highly Sensitive Fluorescent Off‐On Sensor for the Detection of Trace Amount of Water in Organic Solvents and Edible Oilseeds
Authors: Kumar Pawan , Gadiyaram Srushti , Jose D. Amilan
Published: September 2020

Moisture detection in organic solvents and materials by using chemical sensors represent the latest research area in analytical chemistry. In this paper, we report a new fluorescent chemical sensor for the sensitive detection of trace amount of water in Tetrahydrofuran(THF), acetone and acetonitrile. The new probe L.Fe(III) complex consists of the fluorescent reporter dansyl dye attached with Fe(III) ion. Ligand L, and probe L.Fe(III) exhibits solvatochromism by intramolecular charge transfer (ICT) due to the donor‐acceptor properties of the dansyl compound. Probe L.Fe(III) is a non‐fluorescent compound and it becomes highly fluorescent in the presence of trace amount of water in THF, acetone and acetonitrile. The probe shows highly sensitive towards the water in THF with a limit of detection (LOD) as low as 0.0003 weight(wt) %. 1H‐NMR, ESI‐MS and fluorescence lifetime studies established that displacement of metal from the probe is responsible for fluorescent enhancement. Further, for the first time probe L.Fe(III) has been explored as a fluorescence indicator for the qualitative and quantitative detection of trace‐level of water content in various edible oilseeds such as groundnut, mustard, sunflower, sesame and almond.
Mode‐to‐Mode Collision Energy Transfer from Vibrationally Excited C6F6 to NO/N2 Mixed Bath with the Development of New Potential Energy Functions
Authors: Ahamed Sk. Samir , Kumar Pavan , Kalita Hrishikesh , Paul Amit K.
Published: September 2020

Chemical dynamics simulations are performed to study collisional intermolecular energy transfer (IET) from highly vibrationally excited C6F6 to NO/N2 mixed baths equilibrated at 300 K. Two baths with a respective total of 200 and 1000 molecules are considered. The simulations are performed with very accurate intramolecular and intermolecular potential energy parameters either taken from literature or developed. A new simulation methodology is implemented to prepare a three‐component bath system. There is a rise in temperature during the IET dynamics in the smaller bath. The rotational ΔT is observed as 85 K in this bath and is much higher than 20 K obtained at 600 ps from the large bath simulation. However, both the simulations show less average energy transfer as compared to the one obtained from pure N2 bath simulation done previously [J. Chem. Phys. 2014, 140, 194103]. The deviation is less for the large bath simulation. The rotational degree of freedom for NO is found less effective towards IET compared to N2, whereas, the center‐of‐mass translational and vibrational modes behave similar to those of N2.
Stabilization of Supramolecular Assembly of N‐Substituted Benzylidene Acetohydrazide Analogs by Non‐Covalent Interactions: A Concise Experimental and Theoretical Approach
Authors: Khalid Muhammad , Ali Akbar , Tariq Jahrukh , Tahir Muhammad Nawaz , Aliabad Hossein Asghar Rahnamaye , Hussain Ishtiaq , Ashfaq Muhammad , Khan Muhammad Usman
Published: September 2020

Herein, the crystalline N‐substituted benzylidene acetohydrazide derivatives: N′‐(4‐bromo‐2‐fluorobenzylidene)‐2‐((6‐chloropyridin‐2‐yl)oxy) acetohydrazide (BFBAH) and 2‐((6‐chloropyridin‐2‐yl)oxy)‐N′‐(4‐methoxybenzylidene) acetohydrazide (MOBAH) were produced and the structures were characterized and confirmed by the NMR spectroscopy and single crystal analysis. SC‐XRD study disclosed that the molecules are connected with each other in the form of dimers through hydrogen bonding in the crystalline network of BFBAH and MOBAH. Additionally, the theoretical calculations were performed using the DFT/B3LYP/6‐311G(d,p) functional. The hyperconjugation and intermolecular hydrogen bonding were explored by using NBO analysis. Hirshfeld surface analysis analyzing intra and intermolecular interactions, uncovered that supramolecular assemblies have been stabilized by N−H⋅⋅⋅O and C−H⋅⋅⋅O intermolecular hydrogen bonds, as well as van der Waals interactions. The quantum theory of atoms in molecules (QT‐AIM) study corroborates that both significant N−H⋅⋅⋅O and C−H⋅⋅⋅O H‐bonds are strong in nature. Besides, global reactivity indices were computed via the energies of HOMO and LUMO orbitals.
Designing of Ag2S Nanowires from a Single‐Source Molecular Precursor [(PPh3)2AgS2P(OiPr)2] for Hydrogen Evolution Reaction
Authors: Khirid Samreet , Biswas Rathindranath , Meena Sangeeta , Patil Ranjit A. , Ma Yuan‐Ron , Devan Rupesh S. , Dhayal Rajendra S. , Haldar Krishna Kanta
Published: September 2020

In the present study, we illustrated a facile fabrication of large scale ultra‐thin silver sulfide (Ag2S) nanowires (NWs) and its promising application in hydrogen evolution reaction (HER). Ultra‐thin and highly uniform Ag2S nanostructures were fabricated from single‐source precursor [(PPh3)2AgS2P(OiPr)2], and characterized by utilizing various structural and imaging techniques. Large‐scale monodispersed ultra‐thin single‐crystalline Ag2S nanowires were generated via n‐decylboronic acid induced thermal decomposition of the single precursor in the presence of octadecyl amine and oleyl amine mixture under anaerobic conditions. We explored the catalytic activities of Ag2S nanowires for HER which showed an overpotential of−88 mV at 10 mA/cm2 and the corresponding Tafel slope was found to be 52 mV dec−1.
Ultrasonic‐Assisted Hypervalent Iodine‐Catalyzed Cyclization of (E)‐2‐Hydroxystilbenes to Benzofurans Using Iodobenzene as Pre‐catalyst
Authors: Mangaonkar Saeesh R. , Shetgaonkar Samata E. , Vernekar Amit A. , Singh Fateh V.
Published: September 2020

A rapid, and metal‐free approach for the synthesis of functionalized benzofurans 10 is illustrated by PhI 9 catalyzed cyclization of 2‐hydroxystilbenes 8. The 2‐hydroxystilbenes 8 were cyclized using 10 mol % PhI as a precatalyst, 2.0 equiv. of m‐CPBA as an oxidant and 2.4 equiv. of TFA as an additive at room temperature under ultrasonic irradiation condition. The functionalized benzofurans 10 were gained in good to excellent yields with shorter reaction times.
New Dimensions in Rongalite Chemistry: The Land of Opportunities in Organic Synthesis and Material Sciences
Authors: Ali Rashid
Published: September 2020

Rongalite, first time reported in the chemical structure in 1905, also known as bruggolite or sodium formaldehyde sulfoxylate, having good solubility and stability in organic media, is not only a cheap and commercially available (in kg amount) reagent with a range of industrial applications for instance emulsion polymerization, an excellent decolouring agent, antioxidant in pharmaceutical development, and an antidote for heavy metals, but also used as an effective regents in a plethora of organic reactions particularly in redox reactions as a powerful reducing agent. More interestingly, in recent years, it has also shown its impact in material sciences for the preparation of CdTe, CoTe2, and Ag2Se thin films, nanowire networks, hollow nanospheres, copper nanoparticles (Cu‐Nps), CdTe‐quantum dots and so forth. Keeping in mind the importance of this vital reagent in both organic chemistry as well as in material sciences, herein I intended to report the recent developments along with a brief overview of old literature wherever necessary to showcase the utility of this valuable reagent. This particular review article not only covers the applications of this environmentaly benign reagent in organic synthesis but also its usefulness in material sciences in particular nanosciences has been exposed for the first time.
Ruthenium‐Based Structural Mimics of the Cofactor of [Fe]‐Hydrogenase: Replacement of the Acyl Moiety with an N‐Heterocyclic Carbene
Authors: Barik Chandan Kr , Chan Xian Qi , Huynh Han Vinh , Li Yongxin , Ganguly Rakesh , Leong Weng Kee
Published: September 2020

A synthetic route is reported towards ruthenium‐based structural mimics of the [Fe]‐hydrogenase metal cofactor in which the acyl moiety is replaced by an N‐heterocyclic carbene. It is observed that the pyridyl‐NHC ligand has a rather different trans influence from that of a simple NHC in their ruthenium derivatives. The basis for this difference is explored crystallographically and computationally, and it accounts for their different behaviour towards thiolation.
Discovering Podophyllotoxin Derivatives as Potential Anti‐Tubulin Agents: Design, Synthesis and Biological Evaluation
Authors: Han Hongwei , Xu Xinhong , Ma Yingying , Luo Yuelin , Wang Zizhen , Yang Minkai , Wen Zhongling , Zhang Yahan , Yin Tongming , Zhao Quan , Lin Hongyan , Lu Guihua , Yang Rongwu , Wang Xiaoming , Qi Jinliang , Yang Yonghua
Published: September 2020

Podophyllotoxin is a potent cytotoxic agent and serves as a useful lead compound for development of anticancer agents. Tubulin is known as an attractive target for drug discovery and cancer therapies. There are few studies on the treatment of breast cancer with podophyllotoxin and its derivatives targeting tubulin. Here, a series of novel aryl 1,3,4‐oxadiazole/1,3,4‐thiadiazole acid podophyllotoxin ester derivatives (D1–D16) were synthesized. Among these compounds, D9 exhibited excellent antiproliferation activity against MCF‐7 cells (IC50=2.46±0.12 μM). Furthermore, D9 caused cell cycle arrest at the G2/M phase and induced cell apoptosis. Confocal microscopy showed that D9 inhibited microtubule polymerization by causing cancer cell growth inhibition. Molecular docking results suggested D9 could bind to the active binding site of tubulin. In a mouse model, compound D9 suppressed malignant growth without causing significant toxicity to normal tissues. Our findings support the utility of D9 as a novel compound for the development of anticancer agent.
Rational Design of a Replication‐Competent and Inheritable Magnetic Viruses for Targeting Biomedical Applications
Authors: Xu Yan‐Peng , Zhou Hang‐Yu , Wang Guang‐Chuan , Zhang Ying , Yang Tianxu , Zhao Yueqi , Li Rui‐Ting , Zhang Rong‐Rong , Guo Yan , Wang Xiaoyu , Li Xiao‐Feng , Qin Cheng‐Feng , Tang Ruikang
Published: September 2020

Infection with live‐attenuated vaccines always inevitably induces side effects that reduce their safety. This study suggests a concept of magnetic virus produced by genetically modifying viral surfaces with Fe3O4 nanoparticles (NPs) to control their tropisms. An iron‐affinity peptide is designed to be displayed on the viral surface protein (VP1) of human enterovirus type 71 (EV71), a typical nonenveloped picornavirus, as the model. The modified EV71 can self‐bind with Fe3O4 NPs under physiological conditions, resulting in novel EV71‐Fe3O4 hybrid materials. This rationally engineered EV71 with Fe3O4 retains its original biological infectivity, but its tropism can be precisely controlled by magnetism. Both in vitro and in vivo experiments demonstrate that EV71‐Fe3O4 can infect only a desired area within the limit of the applied magnetic field, which effectively reduces its pathological damage. More importantly, this characteristic of EV71 can be inherited due to the gene‐induced coassembly of viruses and NPs. This achievement provides a proof of concept in virus vaccine improvement by a combination of gene modification and material incorporation, leading to great potential for biomedical developments.
A Spheroid‐Forming Hybrid Gold Nanostructure Platform That Electrochemically Detects Anticancer Effects of Curcumin in a Multicellular Brain Cancer Model
Authors: Suhito Intan Rosalina , Angeline Novi , Lee Kwang‐Ho , Kim Huijung , Park Chun Gwon , Luo Zhengtang , Kim Tae‐Hyung
Published: September 2020

In this study, a multifunctional platform that enables the highly efficient formation of 3D multicellular cancer spheroids and precise real‐time assessments of the anticancer effects of curcumin in a brain tumor coculture model is reported. A highly conductive gold nanostructure (HCGN) is fabricated to facilitate cancer spheroid formation without using anti‐cell adhesion molecules. A neuroblastoma (SH‐SY5Y) and glioblastoma (U‐87MG) coculture model is generated on HCGN with a specific cell‐to‐cell ratio (SH‐SY5Y: U‐87MG = 1:1), and their redox behaviors are successfully measured without destroying the distinct 3D structure of the multicellular spheroids. Using electrochemical signals as an indicator of spheroid viability, the effects of potential anticancer compounds on cocultured spheroids are further assessed. Remarkably, decreased cell viability in 3D spheroids caused by a low concentration of curcumin (30 µM) is detectable using the electrochemical method (29.4%) but not with a conventional colorimetric assay (CCK‐8). The detection is repeated more than ten times for both short‐ (63 h) and long‐term cultivation (144 h) without damaging the spheroids, enabling real‐time, non‐destructive pharmacokinetic analysis of various drug candidates. Therefore, it can be concluded that the hybrid platform is a highly promising, precise, and high‐throughput drug screening tool based on 3D cell cultivation.
A Hybrid Organo‐Nanotheranostic Platform of Superlative Biocompatibility for Near‐Infrared‐Triggered Fluorescence Imaging and Synergistically Enhanced Ablation of Tumors
Authors: Akakuru Ozioma Udochukwu , Liu Chuang , Iqbal M. Zubair , Dar Gohar Ijaz , Yang Gao , Qian Kun , Nosike Elvis Ikechukwu , Xing Jie , Zhang Zhoujing , Li Yanying , Li Juan , Wu Aiguo
Published: September 2020

The quest for an all‐organic nanosystem with negligible cytotoxicity and remarkable in vivo tumor theranostic capability is inescapably unending. Hitherto, the landscape of available photothermal agents is dominated by metal‐based nanoparticles (NPs) with attendant in vivo negatives. Here, an all‐organic‐composed theranostic nanosystem with outstanding biocompatibility for fluorescence image‐guided tumor photothermal therapy, and as a potential alternative to metal‐based photothermal agents is developed. This is rationally achieved by compartmentalizing indocyanine green (ICG) in glycol chitosan (GC)‐polypyrrole (PP) nanocarrier to form hybrid ICG@GC‐PP NPs (≈65 nm). The compartmentalization strategy, alongside the high photothermal conversion ability of PP jointly enhances the low photostability of free ICG. Advantageously, ICG@GC‐PP is endowed with an impeccable in vivo performance by the well‐known biocompatibility track records of its individual tri organo‐components (GC, PP, and ICG). As a proof of concept, ICG@GC‐PP NPs enables a sufficiently prolonged tumor diagnosis by fluorescence imaging up to 20 h post‐injection. Furthermore, owing to the complementary heating performances of PP and ICG, ICG@GC‐PP NPs‐treated mice by one‐time near‐infrared irradiation exhibit total tumor regression within 14 days post‐treatment. Therefore, leveraging the underlying benefits of this study will help to guide the development of new all‐organic biocompatible systems in synergism, for safer tumor theranostics.
Drug Targeting via Platelet Membrane–Coated Nanoparticles
Authors: Wang Shuyan , Duan Yaou , Zhang Qiangzhe , Komarla Anvita , Gong Hua , Gao Weiwei , Zhang Liangfang
Published: September 2020

Platelets exhibit distinct surface moieties responsible for modulating their adhesion to various disease‐relevant substrates involving vascular damage, immune evasion, and pathogen interactions. Such broad biointerfacing capabilities of platelets have inspired the development of platelet‐mimicking drug carriers that preferentially target drug payloads to disease sites for enhanced therapeutic efficacy. Among these carriers, platelet membrane–coated nanoparticles (denoted “PNPs”) made by cloaking synthetic substrates with the plasma membrane of platelets have emerged recently. Their “top‐down” design combines the functionalities of natural platelet membrane and the engineering flexibility of synthetic nanomaterials, which together create synergy for effective drug delivery and novel therapeutics. Herein, the recent progress of engineering PNPs with different structures for targeted drug delivery is reviewed, focusing on three areas, including targeting injured blood vessels to treat vascular diseases, targeting cancer cells for cancer treatment and detection, and targeting drug‐resistant bacteria to treat infectious diseases. Overall, current studies establish PNPs as versatile nanotherapeutics for drug targeting with strong potentials to improve the treatment of various diseases.
Anpassung der 2D‐Referenz‐Rissmodelle im Anhang 8 der RiL 805:2012
Authors: Mensinger Martin , Engl Matthias , Rengstl Mathias
Published: September 2020

Das Vorgehen zur Erstellung von 2D‐Referenz‐Rissmodellen entsprechend der Richtlinie 805:2012 Anhang 8 wird schrittweise dargestellt. Dieser Anhang der RiL 805 dient der Festlegung von sicheren Betriebszeitintervallen von bestehenden genieteten Eisenbahnbrücken und wird derzeit überarbeitet. Neben den bruchmechanischen Hintergründen bei genieteten Eisenbahnbrücken wird auch die Anwendung der FEM für 3D‐/2D‐Parameterstudien bei Rissen erläutert. Das Vorgehen zur Definition von Modellbreiten wird aufgezeigt und exemplarisch an einem genieteten Winkel demonstriert.
Negotiating Medical Authority: Shared Decision‐Making in the ICU
Authors: Rodriquez Jason
Published: September 2020

Hospitalized individuals who are unable to communicate have the right to an empowered surrogate who participates in shared decision‐making. Based on 300 hours of participant observation in an intensive care unit (ICU) and 35 interviews with staff, this article examines shared decision‐making as a negotiated social process of aligning frames of understanding. Drawing from Erving Goffman's concepts of frames (1974) and performance teams (1959), this article shows the interactional strategies ICU clinicians as a team used to bring family surrogates' frame of understanding into alignment with their own assessment that the patient was unlikely to survive. Findings show clinicians maintained authority over end‐of‐life care while also maintaining a process recognized as shared decision‐making.
An innovative strategy to regulate bimodal cellular structure in chain extended poly(butylene adipate‐co‐terephthalate) foams
Authors: Cui Yalin , Zhou Haoyan , Yin Dexian , Zhou Hongfu , Wang Xiangdong
Published: September 2020

A facile and effective approach for manufacturing poly(butylene adipate‐co‐terephthalate) (PBAT) foams with obvious bimodal cellular structure (BCS) was proposed utilizing chain extension and batch supercritical CO2 foaming technology. Ethylene‐glycidyl methacrylate copolymer (EGMA) as crystalline chain extender was selected to modify PBAT. The results of torque tests, differential scanning calorimetry, and rheological performances demonstrated that the melt strength, viscoelasticity, and crystallization properties of PBAT were improved after introducing EGMA. The influences of EGMA content and foaming temperature on the cellular structure of PBAT foams were investigated systematically. By decreasing the foaming temperature, the size of both large and small cells in the bimodal chain extended PBAT‐3 (CPBAT‐3) foams decreased, as well as their BCS became distinct gradually. The BCS in diverse CPBAT foams was successfully controlled via varying EGMA content and foaming temperature. Finally, the formation mechanism of BCS in diverse PBAT foams was presented.
Comparative removal efficiencies of natural organic matter by conventional drinking water treatment plants in Zimbabwe and South Africa
Authors: Chaukura Nhamo , Moyo Welldone , Ingwani Thomas , Ndiweni Sikelelwa N. , Gwenzi Willis , Nkambule Thabo I.
Published: September 2020

Natural organic matter (NOM) influences the quality and treatability of drinking water; therefore, its removal is paramount. A few studies exist on NOM removal in developing countries, and comparative studies are even fewer globally. This study compared the removal efficiencies for bulk NOM and biodegradable organic carbon (BDOC) fractions of drinking water treatment plants in Zimbabwe (Z) and South Africa (S). NOM removal efficiency at the coagulation stage of plant Z and plant S was 11% and 13%, respectively. The fluorescence index (FI) for the raw water feeding plant Z (1.66) indicated a mixture of both microbial and terrestrially derived NOM, whereas for plant S the FI (4.08) showed terrestrially derived NOM. Based on the log‐transformed absorbance at the disinfection stage, plant S had a 58% greater opportunity to produce disinfection by‐products than plant Z. The BDOC results for plant Z showed humic fractions were the major substrates for bacterial assimilation, whereas the heterotrophic bacteria in plant S were not particularly selective toward DOC fractions. Overall, the plants had comparable NOM removal performances.

Practitioner points

NOM removal efficiency at the coagulation stage of plant Z and plant S was 11% and 13%, respectively.

Plant Z had a mixture of both microbial and terrestrially derived NOM, whereas plant S had terrestrially derived NOM.

Plant S had a 58% greater opportunity to produce disinfection by‐products than plant Z.

Humic fractions were the major substrates for bacterial assimilation for plant Z, whereas the heterotrophic bacteria in plant S were not selective towards DOC fractions.
Oxidative Addition of 2‐Halogenopyridines and 2‐Chloroquinoline to Zero‐Valent Group 10 Metals
Authors: Jahnke Mareike C. , Pichl Ramona M. C. , Hahn F. Ekkehardt
Published: September 2020

Oxidative addition of the C2–X (X = Cl, Br) bond of 2‐halogenopyridines or 2‐chloroquinoline to zero‐valent group 10 metal complexes in the presence of a proton source leads to complexes bearing pyridine‐derived protic remote NHC (rNHC) ligands. The oxidative addition of 2‐halogeno‐functionalized pyridine derivatives to complexes [M0(PPh3)4] (M = Pd, Pt) in the presence of NH4BF4 or NH4PF6 yielded complexes trans‐[1]PF6–trans‐[5]BF4 with a trans‐arrangement of the two remaining PPh3 ligands. The oxidative addition to Ni0 was achieved by reaction of the halogenopyridine derivatives with [Ni(cod)2]/PEt3 in the presence of a proton acid (NH4BF4 or NH4PF6) yielding complexes of type trans‐[Ni(protic‐rNHC)(PEt3)2X]A (A = BF4–, PF6–). In the absence of a proton source, the oxidative addition of 2‐chloroquinone to [Ni(cod)2]/PEt3 yielded the neutral complex trans‐[8] bearing an anionic quinoline‐derived rNHC ligand. The molecular structures of selected complexes have been determined by X‐ray diffraction studies.
Conformally soft theorem in gravity
Authors: Puhm Andrea
Published: September 2020

Abstract

A central feature of scattering amplitudes in gravity or gauge theory is the existence of a variety of energetically soft theorems which put constraints on the amplitudes. Celestial amplitudes which are obtained from momentum-space amplitudes by a Mellin transform over the external particle energies cannot obey the usual energetically soft theorems. Instead, the symmetries of the celestial sphere imply that the scattering of conformally soft particles whose conformal weights under the 4D Lorentz group SL(2, ℂ) are taken to zero obey special relations. Such conformally soft theorems have recently been found for gauge theory. Here, I show conformally soft factorization of celestial amplitudes for gravity and identify it as the celestial analogue of Weinberg’s soft graviton theorem.
New limits on coloured three jet resonances
Authors: Easa Hassan , Gregoire Thomas , Stolarski Daniel
Published: September 2020

Abstract

We consider experimental limits on colour triplet fermions that decay dominantly to three jets via a scalar mediator that can be on- or off-shell. These fermions arise in top-partner models that can solve the hierarchy problem, and limits on this scenario are weaker than those on traditional top-partner models because of the messy all-hadronic final state with significant backgrounds. We do find, however, that while there are no dedicated searches for this scenario, especially in case of an on-shell mediator, the suite of LHC all- hadronic searches still constrains a significant portion of the parameter space. In particular, we find that searches for pair production of di-jet and tri-jet resonances are complementary, covering different regions of parameter space. We also find that if the final state is rich in b- jets, current limits do not change significantly relative to the scenario with all light jets, and we describe how modifications of current search strategies can improve limits in that case.
Generalized Multipliers for Left-Invertible Operators and Applications
Authors: Pietrzycki Paweł
Published: September 2020

Generalized multipliers for a left-invertible operator T, whose formal Laurent series $$U_x(z)=\sum _{n=1}^\infty (P_ET^{n}x)\frac{1}{z^n}+\sum _{n=0}^\infty (P_E{T^{\prime *n}}x)z^n$$

U
x

(
z
)

=

∑

n
=
1

∞

(

P
E

T
n

x
)

1

z
n

+

∑

n
=
0

∞

(

P
E

T

′

∗
n

x
)

z
n

, $$x\in \mathcal {H}$$

x
∈
H

actually represent analytic functions on an annulus or a disc are investigated. We show that they are coefficients of analytic functions and characterize the commutant of some left-invertible operators, which satisfies certain conditions in its terms. In addition, we prove that the set of multiplication operators associated with a weighted shift on a rootless directed tree lies in the closure of polynomials in z and $$\frac{1}{z}$$

1
z

of the weighted shift in the topologies of strong and weak operator convergence.
Vector Valued Polynomials, Exponential Polynomials and Vector Valued Harmonic Analysis
Authors: Laczkovich M.
Published: September 2020

Let G be a topological Abelian semigroup with unit, and let E be a Banach space. We define, for functions mapping G into E, the classes of polynomials, generalized polynomials, local polynomials, exponential polynomials, and some other relevant classes. We establish their connections with each other and find their representations in terms of the corresponding complex valued classes. We also investigate spectral synthesis and analysis in the class C(G, E) of continuous functions $$f:G \rightarrow E$$

f
:
G
→
E

. It is known that if G is a compact Abelian group and E is a Banach space, then spectral synthesis holds in C(G, E). We give a self-contained proof of this fact, independent of the theory of almost periodic functions. On the other hand, we show that if G is an infinite and discrete Abelian group and E is a Banach space of infinite dimension, then even spectral analysis fails in C(G, E). We also prove that if G is discrete, has finite torsion free rank and if E is a Banach space of finite dimension, then spectral synthesis holds in C(G, E).
Vacuum laser powder bed fusion—track consolidation, powder denudation, and future potential
Authors: Kaserer L. , Bergmueller S. , Braun J. , Leichtfried G.
Published: September 2020

Defects in parts processed by laser powder bed fusion (LPBF) are often triggered by laser/plasma plume interference and spattering. The implementation of a LPBF process in vacuum has been suggested to possibly reduce these effects. Within this study, the effects of process pressure variations between 1 mbar and atmospheric pressure on the generation of single tracks and on the surrounding layer of loose powder particles were studied for CP titanium grade 2 and the Maraging steel 1.2709. Below 10 mbar no single tracks could be generated and the powder layer adjacent to the track was effectively denuded. It was found that the essential mechanism for incorporating powder into the melt pool begins to work at process pressures above 10 mbar and its effectiveness increases with increasing pressure. The amount of powder incorporated into the melt pool depends on the material and the scanning conditions. With identical scanning conditions, this amount of powder is significantly larger for titanium than for steel. For process pressures above 200 mbar, no significant change in the amount of spattering could be found. In this pressure range improved process stability could be possible due to a reduced laser/plasma interaction and an increased laser penetration depth.
Reliability of an adapted core strength endurance test battery in individuals with axial spondylarthritis
Authors: Rausch Anne-Kathrin , Baltisberger Philipp , Meichtry André , Topalidis Beatrice , Ciurea Adrian , Vliet Vlieland Theodora P. M. , Niedermann Karin
Published: September 2020

Objectives

To adapt the core strength endurance test battery (aCSE), previously used for testing athletes, to a target group of patients with axial spondylarthritis (axSpA), to evaluate its intra-tester reliability and its associations with disease-specific factors.

Methods

A cross-sectional study was conducted at axSpA exercise therapy groups, including both axSpA patients and the physiotherapist group leaders (PTs). The aCSE was used to measure the isometric strength endurance of the ventral, lateral, and dorsal core muscle chains (measured in seconds), as well as to assess the disease-specific factors of functional status, self-reported pain, and perceived strength performance. The aCSE was repeated after 7–14 days to measure intra-tester reliability for the same rater (PT group leader). Reliability was calculated as an intra-class correlation coefficient (ICC) using a nested design. The associations between ventral, lateral, and dorsal strength endurance and the disease-specific factors were calculated using Pearson correlation coefficients.

Results

Study participants were 13 PT group leaders and 62 axSpA patients. The latter were all capable of performing the aCSE, with the exception of one individual. A moderate to substantial intra-rater reliability (ICCs (95%CI)) was found for the ventral (0.54 (0.35, 0.74)), lateral (0.52 (0.33, 0.70)), and dorsal (0.71 (0.58, 0.86)) core muscle chains. None of the aCSE measures correlated with the disease-specific factors.

Conclusion

The aCSE was found to be a reliable test battery for assessing core strength endurance in axSpA patients. Interestingly, aCSE performance was not associated with any disease-specific factors.

Key Points • The adapted core strength endurance test battery measures the isometric strength of the ventral, lateral and dorsal core muscle chains. • The adapted core strength endurance test battery showed a moderate to substantial intra-rater reliability for all three muscle chains tested in axSpA patients. • No correlations were found between the adapted core strength endurance test battery and the disease-specific factors of self-reported pain, functional status and perceived strength performance.
A non-linear static approach for the prediction of earthquake-induced deformation of geotechnical systems
Authors: Laguardia R. , Gallese D. , Gigliotti R. , Callisto L.
Published: September 2020

This paper illustrates an original and simple method to predict earthquake-induced deformations of geotechnical systems. The method is an extension of static non-linear analysis, and is conceived to predict the behaviour of geotechnical systems, like supported and unsupported excavations, that during the seismic motion accumulate displacements in a single direction. The seismic capacity of the system is described by its capacity curve, obtained either from a numerical push-over analysis or through a simplified procedure. The corresponding seismic demand is described by a combination of the elastic response spectrum, including basic information on the maximum amplitudes of the seismic motion, and a cyclic demand spectrum, that provides additional information about the equivalent number of cycles that contribute to the accumulation of displacements. In the paper, the method is described in detail and is validated through different procedures, namely: comparisons with experimental results obtained in the geotechnical centrifuge; comparison with results of advanced numerical analyses; extensive comparison, using a large database of seismic records, with the results of non-linear time-domain analyses. In its final part, the paper provides guidance for the practical use of the method for design.