bluuebunny/crossref_metadata_2025 huggingface dataset:
Mathematical models for understanding phenomena: Vortex‐induced vibrations
Authors: Tamura Yukio
Published: October 2020

This is a rather biased review paper emphasizing the importance of “understanding” of phenomena. This paper's purpose is to inspire young researchers to taste the real charms of research by observing the process of development of mathematical models of vortex‐induced vibration phenomena of cylinders for understanding their essential mechanism. It first discusses the limitations of human abilities and important aspects of research. Then, it emphasizes the close relation between understanding and mathematical models, and five conditions for a desirable mathematical model: simplicity; inclusion of all essential properties; possession of physical meanings; wide scope of application; and possibility of development. It refers to Birkhoff's wake‐oscillator (1953), Funakawa's early‐wake model (1969), Nakamura's 2DOF flutter model (1970), the Hartlen‐Currie model (1970), the Iwan‐Blevins model (1974), Tamura's non‐linear wake‐oscillator model with a variable length (1979), and the Tamura–Shimada model (1987) for combined effects of vortex resonance and galloping. Some recent developments of the Tamura–Shimada model are also introduced. Then, it discusses the necessity of accurate experimental capture of early‐wake behavior and the aerodynamic properties of a target cylinder in a given flow condition for further development of Tamura's model and the Tamura–Shimada model. Finally, the necessity for efforts to understand phenomena are emphasized.
Validation of the preconfigured Varian Ethos Acuros XB Beam Model for treatment planning dose calculations: A dosimetric study
Authors: Hu Yunfei , Byrne Mikel , Archibald‐Heeren Ben , Collett Nick , Liu Guilin , Aland Trent
Published: October 2020

Varian (Palo Alto, California, United States) recently released an online adaptation treatment platform, Ethos, which has introduced a new Dose Preview and Automated Plan Generation module despite sharing identical beam data with the existing Halcyon linac. The module incorporates a preconfigured beam model and the Acuros XB algorithm (Ethos AXB model) to generate final dose calculations from an initial fluence optimization. In this study, we comprehensively validated the accuracy of the Ethos AXB model by comparing it against the Halcyon AXB model, the Halcyon Anisotropic Analytical Algorithm (AAA) model, and measurements acquired on an Ethos linac. Results indicated that the Ethos AXB model demonstrated a comparable if not superior dosimetric accuracy to the Halcyon AXB model in basic and complex calculations, and at the same time its dosimetric accuracy in modulated and heterogeneous plans was better than that of the Halcyon AAA model. Despite the fact that the same algorithm was utilized, the Ethos AXB model and the Halcyon AXB model still exhibited variations across a range of tests, although these variations were predominantly insignificant in the clinical environment. The accuracy of the Ethos AXB model has been successfully verified in this study and is considered appropriate for the current clinical scope. On the basis of this study, clinical physicists can perform a data validation instead of a full data commissioning when implementing the Ethos system, thereby adopting a more efficient approach for Ethos installation.
Application of Conjugated Carbonyls in the Synthesis of Heterocycles via Oxidative Cycloaddition and Cyclization Reactions
Authors: Bagdi Avik Kumar , Pattanayak Paramita , Paul Suvam , Mitra Mousree , Choudhuri Tathagata , Sheikh Amir Sohel
Published: October 2020

Synthesis of pharmaceutically active heterocycles is always appealing as the majority of the widely used drugs contain heterocyclic moieties as their core structure. So, the straightforward construction of heterocycles from readily available/accessible reagents is one of the prime targets of the synthetic chemists. In this context, C−H functionalization has emerged as an effective tool for the designing and synthesis of various heterocyclic moieties as it offers a straight‐forward and step‐economic pathway. On the other hand, the readily available/accessible conjugated carbonyls are well‐known reagents for the construction of carbocycles and heterocycles over the years. However, the employment of C−H functionalization of the two C−H bonds of the conjugated alkene in carbocycle/heterocycle synthesis was not so explored. In the last decade, much focus has been paid on the synthesis of various pharmaceutically active heterocycles through C−H bond functionalization of α,β‐unsaturated aldehydes/ketones. These protocols have been developed through either oxidative coupling of conjugated carbonyls with suitable coupling partners or intramolecular C−H bond functionalization of conjugated carbonyls. In this review, we will discuss all the methodologies developed for the synthesis of heterocycles employing intermolecular C−H bond functionalization of conjugated carbonyls. The mechanistic pathways and usefulness of the methodologies will be also highlighted.

magnified image
Soil water infiltration of Subalpine Shrub Forest in Qilian Mountains, northwest of China
Authors: Chang Zongqiang , Ye Xiyan , Zhang Jinghui
Published: October 2020

Soil water infiltration is an inherent characteristic of soil, but its capability varies according to soil types. In this study, soil water infiltration of five subalpine shrub species, Salix gilashanica C. Wang & P.Y. Fu, Caragana jubata (Pall.) Poir., Dasiphora fruticosa (L.) Rydb., Berberis diaphana Maxim., and Caragana angelica Maxim. ex Kom. from Xishui Forest Zone of Qilian Mountain was tested by the double‐rings method. Influences of shrub type on soil water infiltration were analyzed. Research results demonstrate that there are great differences in soil water storage capacity and infiltration performance among different shrubs. Soil water storage capacity and soil water infiltration of S. gilashanica are higher than those of other shrub types, whereas soil water storage capacity and soil water infiltration of dry C. jubata are the lowest. The initial soil water infiltration rate of different shrub types ranges between 3.8 and 53.93 mm min–1 and the steady infiltration rate is 0.95–24.12 mm min–1. Generally, the order of steady infiltration rate is S. gilashanica > C. jubata > D. fruticosa > B. diaphana > C. tangutica. Kostiakov formula and Horton formula were found superior to Philip formula in terms of fitting accuracy in the process of soil water infiltration. Initial soil water infiltration rate and steady infiltration rate have significantly positive correlations with organic contents, natural moisture content, and porosity of soil, especially with non‐capillary porosity. Alternatively, initial soil water infiltration rate and steady infiltration rate showed significantly negative correlations with soil density.
Recommended measures for the efficient care of patients with genetic disorders during the COVID‐19 pandemic in low and middle income countries
Authors: Hamad Lina , Kreidieh Khalil , Nakouzi Ghunwa , Lyon Elaine , Yazbek Soha
Published: October 2020

The coronavirus disease 2019 (COVID‐19) emerged in early 2020 and since, has brought about tremendous cost to economies and healthcare systems universally. Reports of pediatric patients with inherited conditions and COVID‐19 infections are emerging. Specific risks for morbidity and mortality that this pandemic carries for different categories of genetic disorders are still mostly unknown. Thus, there are no specific recommendations for the diagnosis, management, and treatment of patients with genetic disorders during the COVID‐19 or other pandemics. Emerging publications, from Upper‐Middle Income countries (UMIC), discuss the recent experiences of genetic centers in the continuity of care for patients with genetic disorders in the context of this pandemic. Many measures to facilitate the plan to continuous genetic care in a well‐developed health system, may not be applicable in Low and Middle Income countries (LMIC). With poorly structured health systems and with the lack of established genetic services, the COVID‐19 pandemic will easily exacerbate the access to care for patients with genetic disease in these countries. This article focuses on the unique challenges of providing genetic healthcare services during emergency situations in LMIC countries and provides practical preparations for this and other pandemic situations.
Neocortical Slow Oscillations Implicated in the Generation of Epileptic Spasms
Authors: Lee Chih‐Hong , Le John T. , Ballester‐Rosado Carlos J. , Anderson Anne E. , Swann John W.
Published: October 2020

Objective

Epileptic spasms are a hallmark of severe seizure disorders. The neurophysiological mechanisms and the neuronal circuit(s) that generate these seizures are unresolved and are the focus of studies reported here.

Methods

In the tetrodotoxin model, we used 16‐channel microarrays and microwires to record electrophysiological activity in neocortex and thalamus during spasms. Chemogenetic activation was used to examine the role of neocortical pyramidal cells in generating spasms. Comparisons were made to recordings from infantile spasm patients.

Results

Current source density and simultaneous multiunit activity analyses indicate that the ictal events of spasms are initiated in infragranular cortical layers. A dramatic pause of neuronal activity was recorded immediately prior to the onset of spasms. This preictal pause is shown to share many features with the down states of slow wave sleep. In addition, the ensuing interictal up states of slow wave rhythms are more intense in epileptic than control animals and occasionally appear sufficient to initiate spasms. Chemogenetic activation of neocortical pyramidal cells supported these observations, as it increased slow oscillations and spasm numbers and clustering. Recordings also revealed a ramp‐up in the number of neocortical slow oscillations preceding spasms, which was also observed in infantile spasm patients.

Interpretation

Our findings provide evidence that epileptic spasms can arise from the neocortex and reveal a previously unappreciated interplay between brain state physiology and spasm generation. The identification of neocortical up states as a mechanism capable of initiating epileptic spasms will likely provide new targets for interventional therapies. ANN NEUROL 2021;89:226–241
Sugar‐Based Polymers from d‐Xylose: Living Cascade Polymerization, Tunable Degradation, and Small Molecule Release
Authors: Rizzo Antonio , Peterson Gregory I. , Bhaumik Atanu , Kang Cheol , Choi Tae‐Lim
Published: October 2020

Enyne monomers derived from D‐xylose underwent living cascade polymerizations to prepare new polymers with a ring‐opened sugar and degradable linkage incorporated into every repeat unit of the backbone. Polymerizations were well‐controlled and had living character, which enabled the preparation of high molecular weight polymers with narrow molecular weight dispersity values and a block copolymer. By tuning the type of acid‐sensitive linkage (hemi‐aminal ether, acetal, or ether functional groups), we could change the degradation profile of the polymer and the identity of the resulting degradation products. For instance, the large difference in degradation rates between hemi‐aminal ether and ether‐based polymers enabled the sequential degradation of a block copolymer. Furthermore, we exploited the generation of furan‐based degradation products, from an acetal‐based polymer, to achieve the release of covalently bound reporter molecules upon degradation.
The Utilization of Lanthipeptide Synthetases Is a General Strategy for the Biosynthesis of 2‐Aminovinyl‐Cysteine Motifs in Thioamitides**
Authors: Lu Jingxia , Wu Yuan , Li Yuqing , Wang Huan
Published: October 2020

The biosynthesis of thioamitide natural products remains largely unknown, especially for the characteristic C‐terminal 2‐aminovinyl‐cysteine (AviCys) motifs. Herein, we report the discovery that homologues of class‐III lanthipeptide synthetases (LanKCts) encoded outside putative thioamitide biosynthetic gene clusters (BGCs) fully dehydrate the precursor peptides. LanKCt enzymes bind tightly to cysteine decarboxylases encoded inside thioamitide BGCs and the resulting enzyme complex completes the macrocyclization of AviCys rings. Furthermore, LanKCtenzymes are present in the genomes of many thioamitide‐producing strains and participate in the generation of AviCys macrocycles. Together, our study reveals an unprecedented system that lanthipeptide synthetases outside thioamitide BGCs participate in their biosynthesis by specific association with cysteine decarboxylases encoded inside BGCs.
The Synthesis, Bonding, and Transformation of a Ligand‐Protected Gold Nanohydride Cluster
Authors: Dong Jia , Gao Ze‐Hua , Zhang Qian‐Fan , Wang Lai‐Sheng
Published: October 2020

Gold does not react with H2to form bulk hydrides. Here we report the synthesis and characterization of a gold nanohydride protected by diphosphine ligands, [Au22H4(dppo)6]2+[dppo=1,8‐bis(diphenylphosphino)octane]. The Au22core consists of two Au11units bonded by eight Au atoms not coordinated by the diphosphine ligands. The four H atoms are found to bridge the eight uncoordinated Au atoms at the interface. Each Au11unit can be viewed as a tetravalent superatom forming four delocalized Au‐H‐Au bonds, similar to the quadruple bond first discovered in the [Re2Cl8]2−inorganic cluster. The [Au22H4(dppo)6]2+nanohydride is found to lose H atoms over an extended time via H evolution (H2), proton (H+) and hydride (H−) releases. This complete repertoire of H‐related transformations suggests that the [Au22H4(dppo)6]2+nanohydride is a versatile model catalyst for understanding the mechanisms of chemical reactions involving hydrogen on the surface of gold nanoparticles.
On the functionalization and characterization of hydroxyl‐terminated polybutadiene with octyl‐1‐azide and the evaluation of polyurethane elastomers based on such modified HTPB
Authors: Lemos Mauricio Ferrapontoff , Mendes Luis Claudio , Bohn Manfred A.
Published: October 2020

Hydroxyl‐terminated polybutadiene (HTPB) has been modified with azido‐containing substances to be applied in propulsion systems. Pristine HTPB has compatibility issues with energetic polar substances and plasticizers, which is a drawback to develop new high‐energy propellants. This work presents a path for the functionalization of HTPB, carried out through a controlled bulk reaction of it with octyl‐1‐azide. Then it was reacted with isophorone diisocyanate with or without dioctyl adipate (DOA). Structural, thermal, rheological, and dynamic‐mechanical assessments were accomplished. Infrared revealed the arising of absorption bands associated to the CN stretching. From 13C and 1H nuclear magnetic resonances, it is possible to deduce the presence of amine, aziridine, and imine chemical groups, which may promote compatibilization with other polar and energetic substances. The chemical modification induced an increase of viscosity. With respect to the glass–liquid and glass–rubber transitions, the modification shifted them slightly to higher temperatures, but created stiffer networks, in agreement with the increase of polarity and chain interaction due to the presence of N‐containing functionalities. Regarding the solid elastomer binder, the storage shear modulus and molecular mobility were influenced by the type of HTPB and DOA content. In general, the modified HTPB has physical properties like pristine HTPB.
Chemical and morphological effects of blended sulfonated poly(styrene‐isobutylene‐styrene) and isopentylamine for direct methanol fuel cell applications
Authors: Barrios‐Tarazona Karen , Suleiman David
Published: October 2020

In this study, blend membranes based on a combination of sulfonated poly (styrene‐isobutylene‐styrene) (SIBS) with isopentylamine (IPA) were synthetized as potential candidates for direct methanol fuel cell (DMFC) applications. The impact of sulfonation level (57–93 mol%) and percentage of IPA incorporation (1, 3, and 5 wt%) were analyzed via different properties of the resulting membrane. FTIR analysis showed that IPA was successfully incorporated into the sulfonated polymer matrix and also confirmed the interaction between the sulfonic and amine groups. This interaction generates significant morphological changes in the nanostructure of the membranes that are evident through results of small angle x‐ray scattering and atomic force microscopy analysis. Proton conductivity and methanol permeability of the membranes were also analyzed. Proton conductivity was significantly enhanced with the incorporation of IPA at an optimum loading, creating additional paths for the conduction of protons through the membrane. It was also sensitive to the morphological changes produced after the IPA incorporation and the interconnection between the ionic domains. Methanol permeability increased slightly due to the additional water domains and the inability of the isopentyl groups of IPA to block the free‐volume in the membrane. Despite this, the selectivity (proton conductivity over methanol permeability) of the membranes was comparable to the state‐of‐the‐art Nafion®, especially at an optimum IPA incorporation of 3 wt%.
Molecularly imprinted macroporous polymer monolithic layers for L‐phenylalanine recognition in complex biological fluids
Authors: Antipchik Mariia , Dzhuzha Apollinariia , Sirotov Vasilii , Tennikova Tatiana , Korzhikova‐Vlakh Evgenia
Published: October 2020

In present work, the development of macroporous monolithic layers bearing the artificial recognition sites toward L‐phenylalanine has been carried out. The set of macroporous poly(2‐aminoethyl methacrylate‐co‐2‐hydroxyethyl methacrylate‐co‐ethylene glycol dimethacrylate) materials with average pore size ranged in 340–1200 nm was synthesized. The applicability of Hildebrand's and Hansen's theories for the prediction of polymer compatibility with porogenic solvents was evaluated. The dependences of average pore size on theoretically calculated parameters were plotted. The linear trend detected for Hansen's theory has indicated the high suitability of this approach to select appropriate porogens. The synthesized monolithic MIP layers were tested toward the ability to rebind phenylalanine‐derivative in microarray format. The influence of such factors as average pore size of the material, the concentration of template molecule in polymerization mixture, interaction time of analyte with its imprinted sites on binding efficiency were studied. The developed materials demonstrated good analyte rebinding from buffer solution with recognition factors 2.5–3.4 depending on the MIP sample. The comparable rebinding efficiency was also detected when the analysis was carried using complex biological media. The selectivity of phenylalanine binding from the equimolar mixture of structural analogues was 81.9% for free amino acid and 91.2% for labeled one.
Synergistic enhancement of mechanical, viscoelastic, transport, thermal, and radiation aging characteristics through chemically bonded interface in nanosilica reinforced EPDM‐CIIR blends
Authors: Ashok Neelesh , Prakash Karthikeyan , Selvakumar Deepika , Balachandran Meera
Published: October 2020

The study investigates the influence of bis(3‐triethoxysilylpropyl)tetrasulfide (TESPT) grafted nanosilica (NS) reinforcement on the mechanical, viscoelastic, thermal, and transport characteristics as well as behavior after exposure to different cumulative γ‐radiation doses of EPDM‐CIIR blends for application in nuclear and hydrocarbon environments. The tensile strength and modulus of the nanocomposites were enhanced upto 64% and 118%, respectively whereas solvent diffusion coefficient reduced by 22%. The degradation onset temperature improved from 485°C for unfilled blends to 503°C for the nanocomposites. γ‐radiation aging resistance of EPDM‐CIIR blends improved with incorporation of nanosilica, with blends containing 7.5phrNS showing optimum properties and radiation aging resistance. The property improvements are attributed to the dispersion of NS and chemically interfaced covalent linkages between SiO2‐EPDM/CIIR chains that provides large interfacial area for effective stress transfer and creates barrier to free radical and solvent permeation. The applicability of Korsmeyer‐Peppas, Peppas‐Sahlin, and Higuchi models to predict of sorption behavior are investigated. Coats‐Redfern and Horowitz‐Metzger models were employed to evaluate the activation energy for thermal degradation. Slight decline in properties at higher nanofiller contents was due to the formation of agglomerates. TEM, FTIR, and rheological curves were utilized to corroborate these observations. FTIR and ESR analysis provided insight on the chemical changes in the nanocomposites after irradiation.
Supramolecular thermoplastic elastomers via self‐complementary quadruple hydrogen bonding between polybutadiene‐based triblock copolymers
Authors: Dai Lu , Jie Suyun , Bu Zhiyang , Li Bo‐Geng
Published: October 2020

Two series of triblock copolymers, polycaprolactone‐b‐polybutadiene‐b‐polycaprolactone (PCL‐b‐PB‐b‐PCL, CBC) and polylactide‐b‐polybutadiene‐b‐polylactide (PLA‐b‐PB‐b‐PLA, LBL), have been synthesized through the ring‐opening polymerization (ROP) of ε‐caprolactone (ε‐CL)/D,L‐lactide (D,L‐LA) catalyzed by Sn(Oct)2 with hydroxyl‐terminated polybutadiene (HTPB) as a macroinitiator. Then, these triblock copolymers are end‐functionalized with 2‐ureido‐4[1H]‐pyrimidinone (UPy) groups to obtain the supramolecular multiblock copolymers UCBC and ULBL as supramolecular thermoplastic elastomers (TPEs). The thermal properties of UCBC and ULBL samples are measured by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The tensile tests of all the samples prepared are carried out to investigate the influence of the content of hard segments and the microstructure of PB soft segments on the mechanical properties of supramolecular TPEs.
Effectiveness of the preparation of maleic anhydride grafted poly (lactic acid) by reactive processing for poly (lactic acid)/carbon nanotubes nanocomposites
Authors: Verginio Gleice Ellen Almeida , Montanheiro Thais Larissa do Amaral , Montagna Larissa Stieven , Marini Juliano , Passador Fabio Roberto
Published: October 2020

An effective strategy to increase the properties of poly (lactic acid) (PLA) is the addition of carbon nanotubes (CNT). In this work, aiming to improve the surface adhesion of PLA and CNT a new compatibilizer agent was prepared by reactive processing, PLA grafted maleic anhydride (PLA‐g‐MA) using benzoyl peroxide and maleic anhydride. The effectiveness of the PLA‐g‐MA as a compatibilizer agent was verified for PLA/PLA‐g‐MA/CNT nanocomposites. PLA and PLA‐g‐MA samples were characterized by Fourier transform infrared spectroscopy (FT‐IR) to confirm the grafting reaction of maleic anhydride on PLA chains and by rheological analysis to prove the changes in the matrix PLA after the graphitization reaction. Thermal (differential scanning calorimetry and thermogravimetric analysis), mechanical tests (Izod impact strength and tensile test), and morphological characterization were used to verify the effect of the compatibilizer agent. The preparation of PLA‐g‐MA by reactive extrusion processing proved satisfactory and the nanocomposites presented good thermal and mechanical properties. The addition of the PLA‐g‐MA also contributed to the greater distribution of CNT and can be used as an alternative for the production of PLA/CNT nanocomposites.
Polyethylene glycol modified epoxy acrylateUVcurable3Dprinting materials
Authors: Wang Yiyang , Li Cheng , Tuo Xiaohang , Gong Yumei , Guo Jing
Published: October 2020

The purpose of this paper is to research improvement in the flexibility of epoxy acrylate 3D printing materials so as to satisfy the requirements of clothing attachments or accessories. Tensile tests, differential scanning calorimeter, XRD, rheological and Fourier transform infrared analysis were used to measure and compare the performance and characteristics of polyethylene glycol modified bisphenol‐A epoxy acrylate 3D printed samples with different molecular weights and contents. Based on a comprehensive analysis of the experimental results, the E/PEG1000(1/0.2)‐AA sample was revealed to have an optimal composition ratio. After secondary curing, the tensile strength of the sample rose to 8 MPa, with the elongation being converged to 30%. This paper provides a reference for the modification and improvement of flexible UV‐cured 3D printed products.
Spending Wisely: The Role of Cost and Value Research in the Pursuit of Advancing Anatomical Sciences Education
Authors: Maloney Stephen , Pather Nalini , Foo Jonathan , Lazarus Michelle D.
Published: October 2020

Studies of “cost and value” in anatomical sciences education examine not only what works, but at what cost, thus evaluating the inputs and outputs of education. This research provides insights into how to use available resources (e.g., academic time, budgets, infrastructure) as a mechanism to obtaining the maximum outcomes available. The purpose of this viewpoint article is to expand on the application of cost and value concepts to anatomical sciences education, contextualizing these concepts through a deeper dive into the more costly educational approaches of human donor dissection. In doing so, both questions and opportunities are raised for the discipline of anatomical sciences going forward. Educational decisions, inclusive of cost and value appraisals, consider the range of outcomes for which the activity is designed to achieve, and the activity's integration with the philosophy of the educational program it is contributing to; these decisions, thus, evaluate more than just cost alone. Healthcare students' engagement with human donor dissection pedagogy offers an array of reported non‐economic benefits, including non‐traditional discipline‐independent skill (NDIS) development (e.g., professionalism, teamwork skills). These skills are often harder to measure, but are no less important to the final pedagogical decision‐making process. The goal of cost and value research is to create an evidence‐base toward education that delivers maximum value for a given spend. Anatomy educators, researchers, and decision makers who embrace cost and value dialogue, and interpret and apply findings from studies of educational costs, are best positioned to improve the educational value for their learners and provide effective outputs for all stakeholders.
Developmental and reproductive safety evaluation of AV7909 anthrax vaccine candidate in rats
Authors: Mylchreest Eve , Smiley M. Autumn , Ballin Jeff D. , Blauth Bruna , Shearer Jeffry , Reece Joshua , Ionin Boris , Savransky Vladimir
Published: October 2020

The AV7909 vaccine, consists of the Anthrax Vaccine Adsorbed (AVA) bulk drug substance and the immunostimulatory Toll‐like receptor 9 agonist oligodeoxynucleotide adjuvant CPG 7909. The purpose of this research was to evaluate the potential maternal, reproductive, and developmental toxicity of AV7909 in rats to support licensure for use in women of childbearing potential. Groups of first generation (F0) female Sprague Dawley rats were dosed by intramuscular injection with water for injection, adjuvant or AV7909 at a volume of 0.5 ml/dose. Each rat received three vaccinations: 14 days prior to start of the mating period, on the first day of the mating period and on gestation day (GD) 7. There was no maternal mortality. Body weights, weight gain, and food consumption were comparable between groups. Findings in F0 females were limited to transient injection site edema and nodules consistent with immunostimulatory effects of the vaccine and adjuvant. Administration of AV7909 did not affect mating, fertility, pregnancy, embryo‐fetal viability, growth, or morphologic development, parturition, maternal care of offspring or postnatal survival, growth, or development. There was no evidence of systemic inflammation in pregnant rats, based on evaluation of serum concentrations of the acute phase proteins alpha‐2‐macroglobulin and alpha‐1‐acid glycoprotein on GD 21. Anthrax lethal toxin‐neutralizing antibodies were detected in AV7909‐vaccinated F0 females. The antibodies were also detected in the sera of fetuses and F1 pups. Exposure of the fetuses and pups to maternally derived anthrax lethal toxin‐neutralizing antibodies was not associated with developmental toxicity.
One‐step preparation of red‐emitting carbon dots for visual and quantitative detection of copper ions
Authors: Wei Jianfei , Hao Dan , Wei Lifei , Zhang Anying , Sun Chenying , Wang Rui
Published: October 2020

A one‐step solvothermal method for the preparation of carbon dots with red fluorescence (R‐CDs) was put forward, in which sodium citrate and formamide were chosen as precursors, while formamide was adopted as the solvent. The fluorescence emission peak of the as‐prepared R‐CDs remained the same (600 nm) when the excitation wavelength increased from 490 nm to 560 nm, and the fluorescence quantum yield is 35.3%. Furthermore, the fluorescence intensity of the as‐prepared R‐CDs could be selectively quenched by copper ions, and the mechanism of Cu2+ quenching R‐CDs is the combination of static and dynamic quenching. As a result, the R‐CDs were applied for the construction of a fluorescent sensor without any modification for the quantitative and visual detection of copper ions, which is a typical contaminant in water. The limit of detection for the fluorescent sensor was as low as 5 nmol/L, and it can be used to fast and directly confirm whether the content of copper ions in drinking water meets the criteria of the United States Environmental Protection Agency and the World Health Organization.
An LC–ESI/MS/MS method for the determination of lupeol via precolumn derivatization and its application to pharmacokinetic studies in rat plasma
Authors: Wang Ziming , Wang Yu , Yu Tao , Hu Zhiwei , Wang Yang
Published: October 2020

Lupeol, a phytosterol and triterpene, is widely found in edible fruits and vegetables, and has been reported to exhibit a spectrum of pharmacological activities against various disease conditions. In the present study, a derivative generated by the reaction of lupeol with p‐toluenesulfonyl isocyanate was ionizable and fragmentable in the negative mode by electrospray ionization/tandem mass spectrometry. Based on this simple chemical derivatization, a liquid chromatography–electrospray ionization/tandem mass spectrometry method was developed and validated for the quantification of lupeol in rat plasma. The calibration curves were linear (r2 > 0.999) over concentrations from 2.5 to 250 ng/ml for lupeol. The method had an accuracy of 96.0–109.4%, and the intra‐ and inter‐day precisions (RSD) were within ± 15%. The stability data showed that no significant degradation occurred under the experimental conditions. The mean recoveries at three quality control levels were within 88.7–95.7%. No significant matrix effects (105.3–109.8%) were observed in rat plasma. This method was successfully applied to the pharmacokinetic study of lupeol in rat plasma after oral administration.
CD200‐CD200R1 signaling pathway regulates neuroinflammation after stroke
Authors: Zhao Shou‐cai , Heng Xu , Ya‐ping Wang , Di Luan , Wen‐qian Wu , Ling‐song Ma , Chu Zhao‐hu , Xu Yang
Published: October 2020

Objective

To study how the CD200‐CD200R1 signaling pathway modulates poststroke inflammation and advances our knowledge of immune responses to ischemia insults in stroke.

Methods

Focal middle cerebral artery occlusion (MCAO) was induced in mice for 90 min, and mice were sacrificed at 1, 3, and 7 days of reperfusion. CD200, CD200R1, iNOS, and Arg‐1 expression in ischemic brains was assessed by Western blotting (WB), and immunohistochemical (IHC) staining was performed to examine the expression of CD200 on neurons and CD200R1 on infiltrating lymphocytes. The severity of neurobehavioral deficits was evaluated by neurological deficit scores (NDS) and infarction volume estimated by TTC staining. To study the relationship between CD200/CD200R1 expression and the diversity of the neuroinflammatory response in stroke, CD200Fc (CD200R1 agonist) was subcutaneously injected at onset, at 1 day and 2 days after MCAO operation, and the brains were collected for detection at 3 days after MCAO/R (reperfusion).

Results

CD200 expression on neurons increased at 1 day and then decreased at 3 days after MCAO/R, and the expression of CD200R1 on lymphocytes showed an opposite temporal pattern as tested by IHC. The WB results showed that CD200/CD200R1 variance exhibited a similar pattern of IHC results, and the level of iNOS peaked at 1 day and then decreased gradually, but Arg‐1 increased with time after MCAO/R in ischemic brains. After CD200Fc injection, CD200R1 expression significantly increased, and CD200Fc promoted Arg‐1 but inhibited iNOS expression. The infarct volume and NDS of the group treated with CD200Fc were significantly smaller than those of the IgG2a‐treated group.

Conclusions

The CD200‐CD200R1 signaling pathway regulates neuroinflammation after stroke. Stimulation of CD200R1 by CD200Fc promotes the anti‐inflammatory response and alleviates ischemic injury.
Microbial biosurfactants: A broad analysis of properties, applications, biosynthesis, and techno‐economical assessment of rhamnolipid production
Authors: Moutinho Liza Fernandes , Moura Felipe Ramalho , Silvestre Rackel Carvalho , Romão‐Dumaresq Aline Silva
Published: October 2020

Biosurfactants are surface‐active molecules originated from renewable resources, which are produced by microbial fermentation or chemical/enzymatic catalysis. These molecules present important advantages as compared to petrochemical surfactants, given their resistance to extreme conditions, biodegradability, specificity, and environmental compatibility. Besides that, the high production costs hinder its commercialization. In this way, this article aimed to analyze microbial biosurfactants production, focusing on the optimization of metabolic pathways and production processes, to identify key aspects and provide alternatives to allow a cost‐effective production at industrial scale. This was achieved by a broad analysis of biosurfactants properties, applications, and biosynthetic pathways (in terms of yield, cofactors, and energy), in addition to an assessment of production‐associated costs. As a result of the present extensive data survey and analysis, key production aspects are disclosed. The metabolic pathway yield analysis demonstrated that production of biosurfactants can be significantly improved (highest theoretical yield was 0.47 gbiosurfactant/gsubstrate) by the use of biomolecular engineering techniques to generate optimized synthetic pathways. With an alternative proposed pathway for surfactin, yield was improved and imbalance in cofactors and ATP was reduced. Analysis of productive costs indicated that to make rhamnolipids commercial production feasible, the main efforts should focus on lowering substrate costs as well as the identification of energy‐efficient unit operations to lower electricity cost, since these parameters accounted for 19.36 and 78.22%, respectively, of the production costs. The data generated by this analysis highlight the need for multidisciplinary collaboration to make rhamnolipids economically feasible, including biomolecular engineering and process intensification.
Clinical outcomes of newly diagnosed primary CNS lymphoma treated with ibrutinib‐based combination therapy: A real‐world experience of off‐label ibrutinib use
Authors: Chen Feili , Pang Diwen , Guo Hanguo , Ou Qiuxiang , Wu Xue , Jiang Xinmiao , Wei Xiaojuan , Liu Sichu , Huang Ling , Liang Zhanli , Zhou Dong , Li Wenyu
Published: October 2020

Ibrutinib‐based combination therapy with high‐dose methotrexate (HD‐MTX) has recently shown clinical activity against relapse/refractory (R/R) primary central nervous system lymphoma (PCNSL). Herein, we report our real‐world experience of treating 11 newly diagnosed PCNSL patients with the ibrutinib/MTX combination. HD‐MTX was given at 3.5 g/m2 every 2‐week for eight doses. Ibrutinib was held upon HD‐MTX infusion until clearance and was administered daily post‐induction until disease progression, intolerable toxicity, or death. Nine out of 11 patients completed the induction phase and received ibrutinib as maintenance therapy. An objective response rate (ORR) of 82% (9/11) was observed including complete response (64%) and partial response (18%). The median progression‐free survival (PFS) was 7.4 months while the median overall survival (OS) was not reached. The ibrutinib/MTX combination was well tolerated in these treatment‐naïve PCNSL patients with an acceptable safety profile. Moreover, the longitudinal analysis of cerebrospinal fluid (CSF) circulating tumor DNA (ctDNA) revealed that CSF ctDNA detection was closely associated with tumor response, and sustained tumor responses correlated with the clearance of ctDNA from the CSF. In sum, our data not only demonstrated the clinical benefit of the ibrutinib and HD‐MTX combination regimen in treating newly diagnosed PCNSL patients in a real‐world setting, but also highlighted the significance of liquid biopsy including CSF ctDNA in tracing tumor burden and assessing treatment response.
Towards Culturally Specific Solutions: Evidence from Ghanaian Kinship Caregivers on Child Neglect Intervention
Authors: Abdullah Alhassan , Frederico Margarita , Cudjoe Ebenezer , Emery Clifton R.
Published: October 2020

Recognising the signs and finding solutions to the risk and needs of neglected children remains a challenge in child protection practice despite a global increase in the number of reported child neglect cases. This situation is compounded by the impact of cultural practices on how neglect is perceived. Drawing on semi‐structured in‐depth interviews with 31 kinship caregivers, this study sought to explore how the culturally informed traditional kinship care practice in Ghana can be considered an intervention strategy for parental neglect. Proactive intervention, prevention of abandonment and utilisation of family support emerged as ways kinship care practice can help resolve child neglect issues. This study's findings suggest that kinship care options could help prevent severe forms of child neglect and prevent instances of child neglect at their onset. The study highlights the importance of culture and tradition when considering approaches to addressing neglect of children, which could be adapted to other cultures as it provides learning regarding where it is safe to have the extended family involved from the beginning where there is suspected neglect.

Key Practitioner Messages

The traditional culturally informed kinship care practice in Ghana provides a proactive solution to address parental neglect.

Child welfare workers should strengthen cultural approaches to address child neglect and support families by providing intervention measures.

Child welfare workers should encourage kin or kith groups to promote reciprocal supportive relationships as this could be useful in providing protection for neglected children.

‘Explore[s] how the culturally informed traditional kinship care practice in Ghana can be considered an intervention strategy for parental neglect’
Colossal left main to right atrium fistula ligation complicated by left circumflex STEMI
Authors: Medranda Giorgio A. , Lance Shannon , Waksman Ron , Bernardo Nelson L.
Published: October 2020

Congenital left main (LM) coronary artery to right atrium fistulas with progression to aneurysm development are rare. Most patients remain asymptomatic, but for those with progressive symptoms, intervention is required. However, there are potential life‐threatening complications associated with surgical intervention. We present a case of an extremely rare markedly aneurysmal LM to right atrial fistula treated with surgical ligation complicated by inferolateral ST‐elevation myocardial infarction several days post‐operatively treated successfully using mechanical aspiration thrombectomy, a stent‐retriever, balloon angioplasty, and subsequent intravascular ultrasound‐guided percutaneous coronary intervention with drug‐eluting stent.
Enhancement of Photocatalytic Activity for Hydrogen Production by Surface Modification of Pt‐TiO2 Nanoparticles with a Double Layer of Photosensitizers
Authors: Yoshimura Nobutaka , Kobayashi Atsushi , Yoshida Masaki , Kato Masako
Published: October 2020

To investigate the effect of the surface structure of dye‐sensitized photocatalyst nanoparticles, we prepared three types of RuII‐photosensitizer (PS)‐double‐layered Pt‐cocatalyst‐loaded TiO2 nanoparticles with different surface structures, Zr‐RuCP6‐Zr‐RuP6@N wt %Pt‐TiO2, RuCP6‐Zr‐RuP6@N wt %Pt‐TiO2, and RuCP2‐Zr‐RuP6@N wt %Pt‐TiO2 (N=0.2, 1, and 5), and evaluated their photocatalytic H2 evolution activity in the presence of redox‐reversible iodide as the electron donor. Although the driving force of the electron injection from I− to the photo‐oxidized RuIII PS is comparable, the activity increased in the following order: RuCP2‐Zr‐RuP6@1 wt %Pt‐TiO2 < RuCP6‐Zr‐RuP6@1 wt %Pt‐TiO2 < Zr‐RuCP6‐Zr‐RuP6@1 wt %Pt‐TiO2. The apparent quantum yield of Zr‐RuCP6‐Zr‐RuP6@1 wt %Pt‐TiO2 in the first hour reached 1 %. Zeta‐potential measurements suggest that the surface Zr4+‐phosphate groups attracted I− anions to the nanoparticle–solution interface. Our results indicate that the surface modification of dye‐sensitized photocatalysts is a promising approach to enhance photocatalytic activity with various redox mediators.
Synthesis ofN‐HeterocyclicCarbine Silver(I) and Palladium(II) Complexes with Acylated Piperazine Linker and Catalytic Activity in Three Types of C—C Coupling Reactions
Authors: Liu Qingxiang , Zhang Xiantao , Zhao Zhixiang , Li Xinying , Zhang Wei
Published: October 2020

Main observation and conclusion

Two bis‐imidazolium salts LH2·Cl2and LH2·(PF6)2with acylated piperazine linker and twoN‐heterocyclic carbene (NHC) silver(I) and palladium(II) complexes [L2Ag2](PF6)2(1) and [L2Pd2Cl4] (2) were prepared. The crystal structures of LH2·Cl2and 1 were confirmed by X‐ray analysis. In 1, one 26‐membered macrometallocycle was generated through two silver(I) ions and two bidentate ligands L. The catalytic activity of 2 was investigated in Sonogashira, Heck‐Mizoroki and Suzuki‐Miyaura reactions. The results displayed that these C—C coupling reactions can be smoothly carried out under the catalysis of 2.
Improving Soil Fertility and Nutrient Dynamics with Leachate Attributes from Sewage Sludge by Impoundment and Co‐Composting
Authors: Balaganesh Pandiyan , Vasudevan Mangottiri , Natarajan Narayanan , Suneeth Kumar Saragur M.
Published: October 2020

Co‐composting offers a sustainable solution for community level sewage treatment plants (STP) by producing nutrient‐optimized compost. Soils in such treatment vicinity are susceptible for receiving significant quantity of wastewater, capable of causing a radical shift in soil structure and nutrient dynamics. Samples of sludge‐leachate impounded soil (SLIS) and low fertile soil are collected to select the proportioning of sludge‐derived composts (SDC). A series of batch experiments are conducted by mixing pre‐determined quantity of SDC with field soils on weight basis to identify the best proportioning combination. Based on the in‐vessel aerobic cocomposting experiments with reuse of generated leachate (at a rate of 1.0 per week), SDC exhibits good nutrient stability in terms of carbon‐nitrogen ratio (8–11) with effective moisture augmentation from leachate (45%–74%) under non‐isothermal conditions (between 46±2°C and 32±4°C) within 45 days of incubation. Significant nitrogen transformation is exhibited in SLIS samples due to the temporal variations in sludge decomposition as verified through leaching column experiments. Approximately 30% of nutrient (carbon and nitrogen) leaching is prevented due to the improved moisture retention capacity in presence of compost. An empirical correlation has been derived between various analytical measures of organic matter depicting enhanced decomposition stages of sludge in soil amendments.
Distribution and co‐expression of adrenergic receptor‐encoding mRNA in the mouse inferior colliculus
Authors: Williams Charles A. , Miller Kimberly E. , Williams Nisa P. , Portfors Christine V. , Perkel David J.
Published: October 2020

Adrenergic receptors are mediators of adrenergic and noradrenergic modulation throughout the brain. Previous studies have provided evidence for the expression of adrenergic receptors in the midbrain auditory nucleus, the inferior colliculus (IC), but have not examined the cellular patterns of expression in detail. Here, we utilize multichannel fluorescent in situ hybridization to detect the expression of adrenergic receptor‐encoding mRNA in the inferior colliculus of male and female mice. We found expression of α1, α2A, and β2 receptor‐encoding mRNA throughout all areas of the IC. While we observed similar levels of expression of α1 receptor‐encoding mRNA across the subregions of the IC, α2A and β2 receptor‐encoding mRNA was expressed differentially. To account for developmental changes in noradrenergic receptor expression, we measured expression levels in mice aged P15, P20, and P60. We observed little change in levels of expression across these ages. To ascertain the modulatory potential of multiple adrenergic receptor subtypes in a single IC cell, we measured co‐expression of α1, α2A, and β2 receptor‐encoding mRNA. We found greater proportions of cells in the IC that expressed no adrenergic receptor‐encoding mRNA, α1 and α2A adrenergic receptor‐encoding mRNA, and α1, α2A, and β2 receptor‐encoding mRNA than would be predicted by independent expression of each receptor subtype. These data suggest a coordinated pattern of adrenergic receptor expression in the IC and provide the first evidence for adrenergic receptor expression and co‐expression in the subregions of the mouse auditory midbrain.
Dynamics of perineuronal nets over amphibian metamorphosis
Authors: Edwards Jacob A. , Risch Makayla , Hoke Kim L.
Published: October 2020

Extracellular matrix materials known as perineuronal nets (PNNs) have been shown to have remarkable consequences for the maturation of neural circuits and stabilization of behavior. It has been proposed that, due to the possibly long‐lived biochemical nature of their components, PNNs may be an important substrate by which long‐term memories are stored in the central nervous system. However, little empirical evidence exists that shows that PNNs are themselves stable once established. Thus, the question of their temporal dynamics remains unresolved. We leverage the dramatic morphological and behavioral transformations that occur during amphibian metamorphosis to show that PNNs can be highly dynamic in nature. We used established lectin histochemistry to show that PNNs undergo drastic reconstruction during the metamorphic transition. Pre‐metamorphic tadpoles have abundant lectin‐labeled pericellular material, which we interpret to be PNNs, surrounding neurons throughout the central nervous system. During the metamorphic transition, these structures degrade, and begin to reform in the months following metamorphosis. We show that PNN sizes and staining intensity further change over metamorphosis, suggesting compositional rearrangement. We found PNNs in brain regions with putative homology to regions in mammals with known PNN function, and in other shared regions where PNN function is unknown. Our results suggest that PNNs are susceptible to remodeling by endogenous mechanisms during development. Interpreting the roles of PNNs in circuit maturation and stability requires understanding their temporal relationship with the neurons and synapses they surround. Our work provides further impetus to investigate this relationship in tandem with developmental and behavioral studies.