bluuebunny/crossref_metadata_2025 huggingface dataset:
Multimodal system for optical biopsy of melanoma with integrated ultrasound, optical coherence tomography and Raman spectroscopy
Authors: Fedorov Kukk Anatoly , Wu Di , Gaffal Evelyn , Panzer Rüdiger , Emmert Steffen , Roth Bernhard
Published: July 2022

We introduce a new single‐head multimodal optical system that integrates optical coherence tomography (OCT), 18 MHz ultrasound (US) tomography and Raman spectroscopy (RS), allowing for fast (<2 min) and noninvasive skin cancer diagnostics and lesion depth measurement. The OCT can deliver structural and depth information of smaller skin lesions (<1 mm), while the US allows to measure the penetration depth of thicker lesions (≥4 mm), and the RS analyzes the chemical composition from a small chosen spot (≤300 μm) that can be used to distinguish between benign and malignant melanoma. The RS and OCT utilize the same scanning and optical setup, allowing for co‐localized measurements. The US on the other side is integrated with an acoustical reflector, which enables B‐mode measurements on the same position as OCT and RS. The US B‐mode scans can be translated across the sample by laterally moving the US transducer, which is made possible by the developed adapter with a flexible membrane. We present the results on custom‐made liquid and agar phantoms that show the resolution and depth capabilities of the setup, as well as preliminary ex vivo measurements on mouse models with ∼4.3 mm thick melanoma.
Physical insight into the entropy‐driven ion association
Authors: Yang Xiao , Ji Mingyu , Zhang Cong , Yang Xiaoning , Xu Zhijun
Published: July 2022

The ion association is widely believed to be dominated by the favorable entropy change arising from the release of water molecules from ion hydration shells. However, no direct thermodynamic evidence exists to validate the reliability and suitability of this view. Herein, we employ complicated free energy calculations to rigorously split the free energy including its entropic and enthalpic components into the water‐induced contributions and ion–ion interaction terms for several ion pairs from monatomic to polyatomic ions, spanning the size range from small kosmotropes to large chaotropes (Na+, Cs+, Ca2+, F−, I−, CO32−, and HPO42−). Our results successfully reveal that though ion associations are indeed determined by a delicate balance between the favorable entropy variation and the repulsive enthalpy change, the entropy gain dominated by the solvent occurs only for the monatomic ion pairing. The water‐induced entropic contribution significantly goes against the ion pairing between polyatomic anion and cation, which is, alternatively, dominated by the favorable entropy from the ion–ion interaction term, due to the configurational arrangement of polyatomic anions involved in ion association. The structural and dynamic analysis demonstrates that the entropy penalty from the water phase is primarily ascribed to the enhanced stability of water molecules around the cation imposed by the incoming anion. Our study successfully provides a fundamental understanding of water‐mediated ion associations and highlights disparate lengthscale dependencies of the dehydration thermodynamics on the specific types of ions.
Effect of methyl hydrogen sulfate on the formation of sulfuric acid‐ammonia clusters: A theoretical study
Authors: Gao Jiemiao , Wang Rui , Zhang Tianlei , Liu Fengyi , Wang Wenliang
Published: July 2022

Methyl hydrogen sulfate (MHS) as a common nucleation precursor that has important effect on new particle formation (NPF). Liu et al. showed that MHS and sulfuric acid (SA) generation are competitive due to consumption of the common precursor SO3, and the nucleation ability of SA is better than MHS. Thus, MHS inhibits the SA‐DMA‐based clusters formation particularly in regions with high [MO] (methanol) (Liu et al., Proc. Natl. Acad. Sci. U.S.A. 2019, 116, 24,966). However, in regions where [H2O] is much higher than [MO] ([SA] > > [MHS]), the SO3 consumed by the generation of less MHS will not significantly reduce the [SA], whether MHS still inhibits SA‐A‐based clusters formation and how MHS affects the growth pathways of MHS‐SA‐A‐based clusters remains unclear. Hence, quantum chemistry calculations combining Atmospheric Cluster Dynamics Code (ACDC) are used to investigate the role of MHS in the SA‐A‐based system. Our conclusions show two different effects of MHS in NPF process: “inhibiting” in regions with high [MO] and “weakly facilitating” in regions with high [H2O] and low [MO]. The growth pathways show that with the increasing [MHS], the role of MHS in NPF gradually changes from “transporter” to “participator”, and the contribution to the pathways increases from 7 to 85%. Our results contribute to understanding the NPF in low‐temperature regions with different concentrations of MO and H2O.
Imaging diagnosis and research progress of carotid plaque vulnerability
Authors: Zhang Lianlian , li Xia , Lyu Qi , Shi Guofu
Published: July 2022

Ischemic stroke (IS) exhibits a high disability rate, mortality, and recurrence rate, imposing a serious threat to human survival and health. Its occurrence is affected by various factors. Although the previous research has demonstrated that the occurrence of IS is mainly associated with lumen stenosis caused by carotid atherosclerotic plaque (AP), recent studies have revealed that many patients will still suffer from IS even with mild carotid artery lumen stenosis. Blood supply disturbance causes 10% of IS to the corresponding cerebral blood supply area caused by carotid vulnerable plaque. Thrombus blockage of distal branch vessels caused by rupture of vulnerable carotid plaque is the main cause of ischemic stroke. Therefore, how to accurately evaluate vulnerable plaque and intervene as soon as possible is a problem that needs to be solved in clinic. The vulnerability of plaque is determined by its internal components, including thin and incomplete fibrous cap, necrotic lipid core, intra‐plaque hemorrhage, intra‐plaque neovascularization, and ulcerative plaque formation. The development of imaging technology enables the routine detection of AP vulnerability. By analyzing the pathological changes, characteristics, and formation mechanism of carotid plaque vulnerability, this article aims to explore the modern imaging methods which can be used to identify plaque composition and plaque vulnerability to provide a reference basis for disease diagnosis and differential diagnosis.
Application timing optimization of lignite‐derived humic substances for three agricultural plant species and soil fertility
Authors: Zhao Yihan , Naeth M. Anne
Published: July 2022

Coal is mined for energy generation around the world, producing large amounts of waste and extensive disturbances to the environment. Post‐mining lands with sandy soils to be reclaimed for agricultural uses are very challenging. The use of humic substances such as soil amendments has been discussed, although little information is available regarding application timing in the field. We conducted a field experiment over two consecutive growing seasons on a former coal mine in China, to investigate soil and vegetation response to a lignite‐derived humic product called “nano humus” and to determine optimal application timing. Three economically valuable agricultural species, alfalfa (Medicago sativa L.), barley (Hordeum vulgare L.), and sea buckthorn (Hippophae rhamnoides L.), were used for this study. The benefits of the humic product on soil properties and plant growth under field conditions were expressed after 2 yr of application. A single application at the beginning of each growing season provided better results than splitting into two applications, with no impact of duration (months) between applications. A single application significantly increased soil available phosphorus by 63% and potassium by 96% relative to the control; it significantly enhanced total biomass of alfalfa by 749%, barley by 250%, and sea buckthorn by 147%. Our findings provided important practical implications for using a humic material as a soil amendment in coal mine reclamation, with potential applications in other agricultural and reclamation scenarios.
Not just statistics: Exploring the experiences of Mexican deportees
Authors: López Anna , Cisneros Jesus , Marcus Ioana
Published: July 2022

Centering the narratives of seven Mexican deportees, this study explored the consequences of deportation on participants’ mental health. Participants’ accounts of the deportation experience highlighted the frustration, fear, and disappointment individuals often felt after being forced to abandon established lives in the United States. Their narratives captured the challenges involved in migration and deportation. This study highlights the need for mental health counselors to become more knowledgeable of the issues that affect the lives of deportees.
Association of Left Atrial Hemodynamics by Magnetic Resonance Imaging With Long‐Term Outcomes in Patients With Cardiac Amyloidosis
Authors: Benjamin Mina M. , Arora Punit , Munir Muhammad S. , Darki Amir , Liebo Max , Yu Mingxi , Syed Mushabbar A. , Kinno Menhel
Published: July 2022

Background

Left atrial (LA) function and strain patterns by magnetic resonance imaging (MRI) have been investigated as markers of several cardiovascular pathologies, including cardiac amyloidosis (CA). However, associations with clinical outcomes have not been investigated.

Purpose

To compare LA function and strain by MRI in CA patients to a matched cohort of patients without cardiovascular disease (CVD) and evaluate the association with long‐term clinical outcomes in CA patients.

Study Type

Retrospective case control.

Population

A total of 51 patients with CA and 51 age‐, gender‐, and race‐matched controls without CVD who underwent MRI in sinus rhythm.

Field Strength/Sequence

ECG‐gated balanced steady‐state free precession sequence at 1.5 T.

Assessment

All measurements were completed by one investigator (M.M.B.). LA function and strain parameters were measured including LA indexed minimum and maximum volumes, LA reservoir (R), contractile (CT), and conduit (CD) strain. We compared groups after adjusting for age, hypertension, New York Heart Association class, modified staging system (troponin‐I, BNP, estimated GFR) and left ventricular ejection fraction (LVEF) for an endpoint of all‐cause mortality and a composite endpoint of heart failure hospitalization (HFH) or death.

Statistical Tests

Differences between groups were evaluated withttests for continuous variables orχ2tests for categorical variables. A multivariable regression model was used to assess the associations of thePvalues—two‐sided tests—<0.05 were considered statistically significant.

Results

CA patients with median follow up of 4.9 (8.5) months had significantly lower LA strain and higher LA volumes in comparison to the matched cohort. In the multivariable analysis, only LVEF was significantly associated with death while ƐCT (OR 0.6, CI: 0.41–0.89), indexed minimum LA volume (OR 1.06, CI: 1.02–1.13) and indexed maximum LA volume (OR 1.08, CI: 1.01–1.15) were significantly associated with the composite outcome of death or HFH.

Conclusion

In this retrospective study of CA patients, ƐCT and indexed minimum and maximum LA volumes were significantly associated with the composite outcome of death or HFH.

Evidence Level

3

Technical Efficacy

Stage 3
Immunoassay and mass cytometry revealed immunological profiles induced by inactivated BBIBP COVID‐19 vaccine
Authors: Cheng Zhangkai J. , Huang Huimin , Liu Qiwen , Zhong Ruifen , Liang Zhiman , Xue Mingshan , Liu Mingtao , Li Siping , Wang Hongman , Zheng Peiyan , Zheng Chunfu , Sun Baoqing
Published: July 2022

With the global prevalence of COVID‐19 and the constant emergence of viral variants, boosters for COVID‐19 vaccines to enhance antibody titers in human bodies will become an inevitable trend. However, there is a lack of data on antibody levels and the protective effects of booster injections. This study monitored and analyzed the antibody potency and the antibody responses induced by the booster injection in the subjects who received three vaccine doses. The study was conducted in a multicenter collaboration and recruited 360 healthy adults aged 20–74. Participants received the first, second, and booster doses of inactivated Sinopharm/BBIBP COVID‐19 vaccine at 0, 1, and 7 months. Vaccine‐induced virus‐specific antibody levels (SARS‐COV‐2‐IgA/IgM/IgG) were monitored at multiple time points, surrogate virus neutralization test (sVNT), and the spatial distribution and proportion of immune cells and markers were analyzed using the CyTOF method before vaccination and a month after the second dose. The titers of SARS‐CoV‐2‐IgA/IgM/IgG and neutralizing antibodies increased to a high level in the first month after receiving the second dose of vaccine and declined slowly after that. The antibody levels of SARS‐CoV‐2‐IgG and sVNT were significantly increased at 0.5 months after the induction of the booster (p < 0.05). Despite a downward trend, the antibody levels were still high in the following 6 months. The B cell concentration (in humoral sample) a month after the second injection was significantly reduced compared to that before the vaccine injection (p < 0.05). The proportion of the C01 cell cluster was significantly decreased compared with that before vaccine injection (p < 0.05). Individual cell surface markers showed distinctions in spatial distribution but were not significantly different. This study has shown that serum antibody titer levels will decrease with time by monitoring and analyzing the antibody efficacy and the antibody reaction caused by the booster injection of healthy people who received the whole vaccination (completed three injections). Still, the significant peak of the antibody titer levels after booster highlights the recall immune response. It can maintain a high concentration of antibody levels for a long time, which signifies that the protection ability has been enhanced following the injection of booster immunization. Additionally, CyTOF data shows the active production of antibodies and the change in the immunity environment.
Raised breakdown voltage in a high‐voltage recessed LDD‐SOI by submerged SI3N4
Authors: Daneshpajooh Reza , Anvarifard Mohammad K.
Published: July 2022

A new structure of metal‐oxide‐semiconductor field‐effect transistors (MOSFETs) with lateral double‐diffused MOSFET was introduced based on the silicon‐on‐insulator lightly doped‐drain metal‐oxide‐semiconductor field‐effect‐transistor (SOI‐LDD MOSFET) technology, called recessed silicon nitride lateral‐double diffused silicon‐on‐insulator (RS‐LDD SOI). In the proposed structure, a recession was created on the buried oxide layer and filled with a silicon nitride (SI3N4) layer. Silicon nitride makes the electric field distribution more uniform by modulating the electric field in the drift zone, thereby increasing the breakdown voltage of the proposed structure. The simulation results performed with ATLAS software demonstrated the performance improvement of the proposed structure. Increasing the breakdown voltage by 31% compared to the conventional structure was one of the most important achievements of this work. Also, design considerations were made on the submerged part in the buried oxide, which can be an excellent guide to achieving the optimal performance of the proposed structure.
Seasonal transition of precedent Indian Ocean basin mode and subsequent Indian Ocean Dipole without El Niño–Southern Oscillation impact
Authors: Zhang Mengke , Jin Dachao , Wang Xudong , Chen Lin , Luo Jingjia , Wang Ziqian
Published: July 2022

As two pronounced anomaly patterns over the tropical Indian Ocean, the Indian Ocean basin mode (IOBM) and the Indian Ocean Dipole (IOD) feature phase‐locking with seasonal cycle. We find that IOBM and IOD exhibit significant connection without the influence of the preceding El Niño–Southern Oscillation (ENSO). The tropical IOBM cooling in preceding winter, which is accompanied by anomalous westerlies in the lower troposphere of the tropical eastern Indian Ocean, can transit to a positive IOD in subsequent seasons. In boreal spring following a IOBM cooling, the equatorial wind anomalies over the Indian Ocean turn to easterlies due to the Rossby wave response to the decreased precipitation over the Maritime Continent region. The increased zonal gradient of the sea surface temperature anomalies in the tropical Indian Ocean favours the intrinsic Bjerknes feedback to build up a positive IOD. With the reinforcing process of the weakened Walker circulation in the tropical Indian Ocean, the positive IOD events develop during boreal summer and then reach the peak in following autumn. These results demonstrate that the IOD is transited from the preceding IOBM, which is independent of the influence of the preceding ENSO in boreal winter.
Synthesizing evidence from the earliest studies to support decision‐making: To what extent could the evidence be reliable?
Authors: Yu Tianqi , Lin Lifeng , Furuya‐Kanamori Luis , Xu Chang
Published: July 2022

In evidence‐based practice, new topics generally only have a few studies available for synthesis. As a result, the evidence of such meta‐analyses raised substantial concerns. We investigated the robustness of the evidence from these earliest studies. Real‐world data from the Cochrane Database of Systematic Reviews (CDSR) were collected. We emulated meta‐analyses with the earliest 1 to 10 studies through cumulative meta‐analysis from eligible meta‐analyses. The magnitude and the direction of meta‐analyses with the earliest few studies were compared to the full meta‐analyses. From the CDSR, we identified 20,227 meta‐analyses of binary outcomes and 7683 meta‐analyses of continuous outcomes. Under the tolerable difference of 20% on the magnitude of the effects, the convergence proportion ranged from 24.24% (earliest 1 study) to 77.45% (earliest 10 studies) for meta‐analyses of few earliest studies with binary outcomes. For meta‐analyses of continuous outcomes, the convergence proportion ranged from 13.86% to 56.52%. In terms of the direction of the effects, even when only three studies were available at the earliest stage, the majority had the same direction as full meta‐analyses; Only 19% for binary outcomes and 12% for continuous outcomes changed the direction as further evidence accumulated. Synthesizing evidence from the earliest studies is feasible to support urgent decision‐making, and in most cases, the decisions would be reasonable. Considering the potential uncertainties, it is essential to evaluate the confidence of the evidence of these meta‐analyses and update the evidence when necessary.
Immunohistochemical localization of d‐β‐aspartic acid in congenital and acquired middle ear cholesteatoma
Authors: Kitaya Shiori , Ikeda Ryoukichi , Suzuki Jun , Oshima Hidetoshi , Nomura Yuri , Kusano Yusuke , Ohta Nobuo , Kawase Tetsuaki , Ise Kazue , Murakami Kazuhiro , Nakamura Yasuhiro , Sasano Hironobu , Katori Yukio
Published: July 2022

Objective/Hypothesis

Middle ear cholesteatoma is characterized by abnormal growth of the keratinizing squamous epithelium of the temporal bone. d‐β‐aspartic acid is the major isomer of d‐aspartic acid found in elderly tissue. We assessed the immunoreactivity to k‐β‐aspartic acid of congenital and acquired middle ear cholesteatomas.

Study Design

Case–control studies.

Material and Methods

Tissue samples were collected from 21 patients comprising 21 ears with congenital middle ear cholesteatoma and 26 patients comprising 29 ears with acquired type. Their clinical and histopathological features were investigated. We divided the middle ear cholesteatoma samples into three layers: the perimatrix, matrix, and cystic contents. The patterns of immunoreactivity to d‐β‐aspartic acid expression were then assessed immunohistochemically.

Results

Two patterns of immunoreactivity to d‐β‐aspartic acid were detected in middle ear cholesteatoma: infiltrative and diffuse. In congenital middle ear cholesteatoma, d‐β‐aspartic acid expression was observed throughout all the layers (perimatrix, matrix, and cystic contents), and immunoreactivity to d‐β‐aspartic acid was dramatically strong in all layers. The expression levels of d‐β‐aspartic acid to the cystic content and perimatrix were significantly higher in congenital middle ear cholesteatoma than in the acquired type.

Conclusions

This study showed the expression levels of d‐β‐aspartic acid in middle ear cholesteatoma to differ significantly between congenital and acquired middle ear cholesteatoma. Our results indicate that overexpression of d‐β‐aspartic acid is likely to be involved in the pathogenesis of cholesteatoma, and we speculate that d‐β‐aspartic acid could be a novel biomarker for, and a therapeutic target in, congenital and acquired middle ear cholesteatoma.

Level of Evidence

4
Riverine bacterioplankton and phytoplankton assembly along an environmental gradient induced by urbanization
Authors: Isabwe Alain , Yang Jun R. , Wang Yongming , Wilkinson David M. , Graham Emily B. , Chen Huihuang , Yang Jun
Published: July 2022

Longitudinal environmental heterogeneity and directionality of the water movement are key features that may exert contrasting forces on riverine plankton assembly. Directionality strengthens dispersal‐driven assembly, but this can be masked by urbanization‐induced environmental heterogeneity along the river continuum. In the light of this contrast, we aimed at delineating the relative importance of assembly processes generating distribution patterns of bacterioplankton and phytoplankton communities in a river draining an urbanizing watershed in Southeast China. We applied variation partitioning analysis, neutral community model, and quantitative process estimate on molecular and morphological plankton data obtained over the years 2012–2016. Despite a relatively short distance between sampling sites (< 20 km), plankton community similarity decreased with increasing distance from the upstream pristine site toward the downstream urban area, and formed clusters that roughly corresponded to five habitat patches, predefined based on hydrology and longitudinal landscape change. These distribution patterns were predominantly driven by deterministic and stochastic processes for phytoplankton and bacterioplankton, respectively, indicating a balance between dispersal due to fluvial connectivity and local selective pressures. Considering the global loss of river connectivity due to downstream fragmentation and flow regulation, our findings imply that plankton‐based ecological approaches could be useful to hedge against an uncertain future of rivers draining urbanizing watersheds in an ecologically sustainable way.
Degradable Hemostatic Antibacterial Zein Nanofibrous Mats as Anti‐Adhesive Wound Dressing
Authors: Wang Yang , Li Rong , Liu Ying , Huang Yingxiang , Zhang Jianxun , Ren Xuehong
Published: July 2022

Strong blood adhesion to dressing may cause secondary damage to the wounds during the wound dressing replacement process. Thus, blood repellent dressings have significant potential applications in wound treatment. Herein, a hydrophobic, degradable, and antibacterial dressing is reported to reduce the blood adhesion and prevent infection around the wounds. The dressing is prepared by cross‐linked non‐woven zein nanofibers with quaternized titanium dioxide (TiO2) nanoparticles coating. The dual hydrophobic structures supported by zein nanofibers and the quaternized TiO2 nanoparticles coating provide outstanding water/blood repellency for the dressing, and efficiently prevent blood leakage. Meanwhile, the dressing also possesses appropriate moisture permeability (2194 ± 143 mL m−2 per day). In addition, the quaternized TiO2 nanoparticles coating provides excellent bactericidal activity against Gram‐negative Escherichia coli O157:H7 and Gram‐positive Staphylococcus aureus, especially under visible Xe lamp illumination. Evaluations of hemolysis and cytocompatibility confirm that the fabricated mat is biocompatible and non‐toxic to the cells. Considering the excellent degradable features, the dressing may become a promising environmentally friendly biomedical material.
Investigation of the similarity between physical tests and fatigue simulation of flange yoke made of C45 E material used in cardan shafts
Authors: Ozbakiş M. , Yeni E.C. , Kahyalar M.C.
Published: July 2022

This study is focused on experimental and numerical estimation of the fatigue life of a flange yoke. The material's stress‐life (fatigue) curve (S−N curve) for axial loading is constructed using specimens extracted from actual flange yokes. The torsional fatigue lives of components are determined by torsional fatigue tests of the complete cardan shafts. Simulation of the cardan shaft model including the flange yoke is carried out in Catia V5 R6 2016 software, which is then transferred to Altair Hyperworks 2017 software for the stress analyses. To predict the number of cycles to failure, the results are transferred into nCode 2018 DesignLife analysis module. An aim is to employ the stress‐life curves as input in numerical calculations and finite element analyses to minimize the costly and time‐consuming experimental work. The results show that physical testing and analysis results are in accordance when S−N curve of actual component material, as well as surface roughness factors measured from real component surface affecting fatigue life are incorporated into the analysis.
Corrosion behavior of as‐cast magnesium‐4 % zinc alloys in simulated body fluid solution: the influence of minor calcium and manganese addition
Authors: Yu J. , Wang L. , Wang Y. , Cao X. , Li Y. , Xing B. , Lu L. , Cheng W. , Wang H. , Shin K. S. , Vedani M.
Published: July 2022

Biodegradable magnesium alloys have been extensively investigated for medical applications. In order to explore magnesiumg alloys with good degradable resistance, the effects of minor amounts of calcium and manganese elements on the corrosion behaviors of newly designed as‐cast degradable Mg‐4Zn‐xMn‐xCa alloys have been investigated systematically in this study. The microstructural evolution of various magnesium alloys are measured by optical microscopy, x‐ray diffraction, and scanning electronic microscopy. The corrosion properties are studied through immersion tests and electrochemical measurements. The results show that the grains are refined and the distribution of the intermetallic Mg‐4Zn‐xMn‐xCa alloys is rearranged by adding calcium and manganese elements. The lowest corrosion rate of 3.79 mm/y is achieved on the as‐cast Mg‐4Zn alloy with 0.2 wt.% calcium and 1 wt.% manganese addition. Besides, the corrosion potential (Ecorr) shifted to −1.546 VSCE with the addition of 0.2 wt.% calcium and 1 wt.% manganese. This is because the grain size refinement and the formation of Mg2Ca and Ca2Mg6Zn3 phases. The as‐cast Mg‐4Zn‐1Mn‐0.2Ca alloy can be considered an ideal material for biodegradable implant material application.
New documentary on youths reminds field of need for greater progress
Authors: Enos Gary
Published: July 2022

As much as renowned filmmaker Ken Burns' latest project has targeted the general public in its education about childhood mental illness, Hiding in Plain Sight: Youth Mental Illness also can serve as a stark reminder to the professional community about the need to correct flaws in the mental health system. In essence, the patients and professionals who are featured in the four‐hour documentary remind us that the system still falls short of qualifying to be called a system at all.
Inverse nodal problem for Dirac operator with integral type nonlocal boundary conditions
Authors: Ozkan A. Sinan , Adalar İbrahim
Published: July 2022

In this paper, Dirac operator with some integral type nonlocal boundary conditions is studied. We show that the coefficients of the problem can be uniquely determined by a dense set of nodal points. Moreover, we give an algorithm for the reconstruction of some coefficients of the operator.
Operators Need to Know Sample Collection QA/QC
Authors: Adams Hunter , Ash Steve , Holloway Nicole , Turner Elizabeth , Selar Niranjan , Wagner Mary Carol , Southard Mark
Published: July 2022

Understanding that sample collection quality assurance/quality control can make or break water quality data reliability is key for operators to make informed decisions.
Mechanical and thermal properties of flax/carbon/kevlar based epoxy hybrid composites
Authors: T. G. Yashas Gowda , A. Vinod , P. Madhu , Mavinkere Rangappa Sanjay , Siengchin Suchart , Jawaid Mohammad
Published: July 2022

In recent years, awareness on environmental issues has led to development of biobased materials for a variety of engineering structural applications. Nowadays, researchers and scientists are focusing their efforts on the development of sustainable materials that make use of readily available, renewable, and biodegradable natural resources. While significant progress has been made in the study of hybrid fiber reinforced composites, the fundamental problem of incorporating and selecting the optimal combination of reinforced fibers for various applications has not been adequately addressed. Hence present study addresses the use of combination of two natural fibers with different synthetic fibers to assess the performance of the hybrid fibers composites to develop for engineering applications. In present work the effect of stacking sequence on the mechanical and thermal property of the flax, kevlar, carbon and carbon‐kevlar hybrid fiber reinforced epoxy composites are studied. The four layered composite laminates with different stacking sequence were fabricated using hand layup technique to study the mechanical properties such as tensile, flexural, interlaminar shear, and impact tests, thermal behavior, water absorption, contact angle measurement and scanning electron microscopy. The hybrid carbon/flax composite (CFFC) had better strength as compared to KFFC, HFFC, and FFFF composite laminates with better tensile strength (178.48 MPa), tensile modulus (2132 MPa), flexural strength (378.86 MPa), flexural modulus (15.76 GPa) and interlaminar shear strength (13.91 MPa) and impact strength (13.86 MPa) and water absorption behavior. The stacking sequence revealed that the hybridization of the flax with the synthetic fiber enhanced the properties as compared to the pure flax composites. The influence of the synthetic fibers at outer skin layer had the effect on enhancing the properties of composites. From the obtained results we can effectively utilize the hybrid flax fibers in some various lightweight engineering applications.
Plasma methane activation on mesoporous silica for energy efficiency improvement
Authors: Park Kilsu , Park Daeil , Kim Taegyu
Published: July 2022

This study describes plasma CH4 activation on mesoporous silica (SBA‐15) with a high specific surface area (SSA) for energy efficiency improvement. A dielectric barrier discharge plasma was used, and the SSA of SBA‐15 was varied by controlling the hydrothermal reaction (HR) temperature. The effect of the SSA was investigated to improve the plasma CH4 activation. The synthesized SBA‐15 had a well‐ordered two‐dimensional hexagonal structure. CH4 conversion and C2 selectivity using plasma catalysis were twice as high as those using only the catalyst, because vibrationally excited CH4 can be adsorbed with low activation energy. Additionally, the energy efficiency was higher than that of other plasma catalysts when the plasma was applied to mesoporous SBA‐15 with the SSA of 516 m2 g−1 at a discharge frequency of 0.1 kHz.
Strain Rate and Temperature Effects of the JOXL‐1 Explosive
Authors: Zhu Xintao , Zhang Xiaojing , Li Wenbin , Yao Wenjin
Published: July 2022

To determine the influence of temperature and strain rate on the mechanical behavior of JOXL‐1 explosive, the stress‐strain curves of JOXL‐1 explosive at different temperatures (233 K‐473 K) and different strain rates (110 s−1‐400 s−1) were measured using a split Hopkinson pressure bar (SHPB) experimental system with a temperature control device. The results show that the dynamic mechanical properties of this explosive are sensitive to the strain rate and temperature in the experimental temperature range. The failure stress increases with increasing strain rate and decreases with increasing temperature. The failure strain increases with increasing strain rate, but it is almost unaffected by temperature. The DSC analysis shows that the JOXL‐1 explosive has good thermal stability when the temperature is lower than 391.37 K and that binders in the explosive gradually decompose when the temperature is higher than 391.37 K.
Experimental measurement and theoretical prediction for lower flammability limits of ternary hydrocarbon mixtures
Authors: Qi Chang , He Meng , Ning Ye , Chen Sheng , Yan Xingqing , Wang Yalei , Yu Xiaozhe , Yu Jianliang
Published: July 2022

The present work experimentally investigated the lower flammability limits of methane‐ethylene‐propane‐air mixtures at ambient temperature and pressure in a 20 L confined chamber. Moreover, a calculated flame temperature (CFT) modeling for predicting the lower flammability limit of multicomponent mixed combustible gas was proposed based on the law of conservation of energy. The results indicated that the relative error of Le Chatelier's law is 2.88% in the prediction of the lower flammability limit of the tested multicomponent mixed combustible medium. Also, the relative error of CFT modeling is only 1.47%, which is reduced by 48.96% and can significantly improve the prediction accuracy of the lower flammability limit of multicomponent mixtures. Furthermore, using the premixed laminar flame speed reactor, the USC 2.0 mechanism was employed to obtain the behavior of ternary hydrocarbon mixtures near the flammability limits. The sensitivity analysis showed that competition between the chain branching reaction R1 (H + O2 ⟺ O + OH) and the chain termination reaction R12 (H + CH3(+M) ⟺ CH4(+M)) was crucial in determining the lower flammable limit.
Tanshinone IIA improves contextual fear‐ and anxiety‐like behaviors in mice via the CREB/BDNF/TrkB signaling pathway
Authors: Jiang Yong‐li , Wang Xin‐shang , Li Xu‐bo , Liu An , Fan Qing‐yu , Yang Le , Feng Ban , Zhang Kun , Lu Liang , Qi Jing‐yu , Yang Fan , Song Da‐ke , Wu Yu‐mei , Zhao Ming‐gao , Liu Shui‐bing
Published: July 2022

Posttraumatic stress disorder (PTSD) is one of the most common psychiatric diseases, which is characterized by the typical symptoms such as re‐experience, avoidance, and hyperarousal. However, there are few drugs for PTSD treatment. In this study, conditioned fear and single‐prolonged stress were employed to establish PTSD mouse model, and we investigated the effects of Tanshinone IIA (TanIIA), a natural product isolated from traditional Chinese herbal Salvia miltiorrhiza, as well as the underlying mechanisms in mice. The results showed that the double stress exposure induced obvious PTSD‐like symptoms, and TanIIA administration significantly decreased freezing time in contextual fear test and relieved anxiety‐like behavior in open field and elevated plus maze tests. Moreover, TanIIA increased the spine density and upregulated synaptic plasticity‐related proteins as well as activated CREB/BDNF/TrkB signaling pathway in the hippocampus. Blockage of CREB remarkably abolished the effects of TanIIA in PTSD model mice and reversed the upregulations of p‐CREB, BDNF, TrkB, and synaptic plasticity‐related protein induced by TanIIA. The molecular docking simulation indicated that TanIIA could interact with the CREB‐binding protein. These findings indicate that TanIIA ameliorates PTSD‐like behaviors in mice by activating the CREB/BDNF/TrkB pathway, which provides a basis for PTSD treatment.
Learning to become ignorant: Improving the quality of epistemic knowledge in science education
Authors: Tan Michael , Koh Teck Seng
Published: July 2022

In considering goals for science education, it is conventional to make arguments for the utility of scientific knowledge for a variety of purposes. Less prominent are rationales based on the beauty or truth of science. In this paper, we examine how an approach to science education might be different if we shift the goals of communication to an appreciation of the ways in which our knowledge is limited, and how the practical boundaries of our knowledge can be closer than we think—in other words, how we are collectively ignorant. Key to this approach is a renewed understanding of the role of material investigations in providing partial knowledge. Instead of providing incontrovertible evidence, empirical investigations provide a form of “explanatory excess” whereby the appropriate choice of explanation is not necessarily one that can be simplistically determined. Although scientific practices provide techniques to minimize the possibility of error in making our conclusions, these practices are performed by fallible human communities, from which the notion of “tentative, yet durable” claims derives. We argue that public scientific literacy may be better served by more circumspect claims of validity, and crucially, an enhanced understanding of the ways in which materiality influences epistemic processes and limits our claims. We illustrate these proposals through the case of the International Young Physicists' Tournament, a contest that invites participants to play with interesting physical phenomena for over a year. We identify three factors prominent in these tournament problems that present possibilities for increasing the authenticity of practical investigations. These are (i) multiple physical interactions in phenomena leading to the openness of choice of explanatory theory; (ii) the qualitative, subjective nature of the explanatory utility of theories; and (iii) the material contingency of empirical investigations. We argue that a more open‐handed embrace of the limits of our knowledge may serve as a better epistemic orientation for science instruction.
The Potentiality and the Consequences of Surplus: Agricultural Production and Institutional Transformation in the Northern Basin of Mexico
Authors: Morehart Christopher
Published: July 2022

Social scientists define surplus as excess, either excess production beyond a physiologically defined threshold or excess labor that can then be routed to “non‐productive” means. Methodologically, this model is advantageous and simplifies analysis. Yet this approach can render social minimums as secondary to biological minimums and economic production as distinctive from social production. Subjectively, meeting biological requirements often are secondary to meeting societal obligations. Many producers in past states, for example, had to pay a set tax even in cases of poor yields. Today, paying one's rent or mortgage can entail sacrificing a healthy diet. Simultaneously, social and economic opportunities also shape surplus production—the ability to enrich relationships, participate in the market, host significant events, and gain prestige. Documenting biological minimums, while allowing us to recognize excess methodologically, sometimes has limited value in understanding surplus subjectively. Surplus represents a potentiality, which can be employed creatively or destructively. Within these extremes lay real people, both the powerful and the powerless, making decisions and inheriting their consequences.
Modeling multivariate age‐related imaging variables with dependencies
Authors: Lee Hwiyoung , Chen Chixiang , Kochunov Peter , Elliot Hong Liyi , Chen Shuo
Published: July 2022

Neuroimaging techniques have been increasingly used to understand the neural biology of aging brains. The neuroimaging variables from distinct brain locations and modalities can exhibit age‐related patterns that reflect localized neural decline. However, it is a challenge to identify the impacts of risk factors (eg, mental disorders) on multivariate imaging variables while simultaneously accounting for the dependence structure and nonlinear age trajectories using existing tools. We propose a mixed‐effects model to address this challenge by building random effects based on the latent brain aging status. We develop computationally efficient algorithms to estimate the parameters of new random effects. The simulations show that our approach provides accurate parameter estimates, improves the inference efficiency, and reduces the root mean square error compared to existing methods. We further apply this method to the UK Biobank data to investigate the effects of tobacco smoking on the white matter integrity of the entire brain during aging and identify the adverse effects on white matter integrity with multiple fiber tracts.
Substituent Effect: Synthesis of Three TNP‐Detecting Fluorescent Probes Based on Triazolothiadiazole‐Quinazolinone**
Authors: Zhang Chenglu , Wang Yiming , Jiang Yanhua , Zhang Yining , Xie Yanxuan , Gong Rongqing , Hao Qiang
Published: July 2022

Three novel fluorescent probes (QZLSZ‐1∼QZLSZ‐3) were designed and synthesized based on quinazolinone for comparing the representative substituent effects on QZLSZ fluorescence detection of 2, 4, 6‐trinitrophenol (TNP). The results show that the probes all exhibit high selectivity and good photo‐stability in wide pH rang and high quenching efficiency, indicating the rational structural design. Compared the substituent effects on the fluorescent properties of QZLSZ, it is found that electron ‐ donating group in QZLSZ‐1 is more favorable than the electron‐withdrawing group in QZLSZ‐3. The probe QZLSZ‐1 has the highest fluorescence quantum yield (0.5407) and the biggest Storks shift (191 nm). Furthermore, it has the lowest detection limit (0.16 μM), the optimal sensitivity (1.3 × 105 M−1), the largest detection range (10∼50 μM) and the rapidest response time (60 s) for the fluorescence recognition of TNP. The theoretical calculation results using Density functional theory (DFT) are highly consistent with that of the experiments. Particularly, QZLSZ‐1 has the best practical application value for qualitative and quantitative fluorescence detection of TNP in actual water samples.
Synthesis and Characterization of Zinc Oxide Nanoparticles Using Thermophilic Bacteria Isolated from Arid Region of Rajasthan
Authors: Parihar Jagdish , Kumawat Ashok , Misra Kamakhya Prakash , Bagaria Ashima
Published: July 2022

Four bacterial strains were used for biosynthesis of zinc oxide (ZnO) nanoparticles (NPs), namely Bacillus tropicus SHJP5, Bacillus tropicus LKJP6, Aeribacillus composti SJP25, and Aeribacillus pallidus SJP28. The synthesized nanoparticles were characterized using UV‐Visible spectroscopy (UV‐Vis), Fourier transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), Photoluminescence spectroscopy (PL), Thermogravimetric analysis (TGA), and X‐ray diffraction (XRD). The XRD pattern of NPs (bio‐synthesized) shows the polycrystalline hexagonal wurtzite structure with the three major planes (100), (002), and (001). The average crystallite size determined by the Debye‐Scherrer equation is between 8–54 nm. A reduction in crystallite size of as‐prepared nanoparticles was observed in the presence of bacterial strains. The FTIR analysis reveals the amide, carboxyl, and hydroxyl groups found on the surface of biosynthesized ZnO NPs. These groups behave as reducing and stabilizing agents. The UV‐Vis spectra reveal the absorption bands for control, SHJP5, LKJP6, SJP25, and SJP28 at 373, 363, 382, 358, and 380 nm respectively. The corresponding energy band gap was found to be 3.324, 3.415, 3.246, 3.463, and 3.263 eV respectively, with the decreasing size of the nanoparticles produced by bacterial strains. The FESEM analysis confirms the hexagonal structure of bio‐synthesized ZnO NPs. The nanoparticles have a uniform distribution of spherical shape except for the strain Aeribacillus pallidus LKJP6 which exhibits uniform and thin nanorods. Minimum inhibitory concentration (MIC) tests against E. coli (7.1 mg/ml) and S. aureus (3.2 mg/ml) verified the antibacterial activity of produced ZnO NPs. The use of isolated strains for the extracellular manufacture of ZnO NPs is encouraged in this work. To the best of our knowledge, this might be the first study that has been presented that shows the structural, optical, and surface morphology of a thermophilic bacterium, Bacillus tropicus SHJP5, Bacillus tropicus LKJP6, Aeribacillus composti SJP25, and Aeribacillus pallidus SJP28 for the biosynthesis of ZnO NPs in particular.
Photocatalyzed gem‐Difluoroallylation of Tertiary Amines with α‐Trifluoromethyl Alkenes
Authors: Yang Chunhui , Chen Jingchao , Li Xinhan , Yang Xiaoju , Zhu Yuanbin , Wu Shiyuan , Zeng Guangzhi , Wang Kaimin , Fan Baomin
Published: July 2022

The gem‐difluoroalkene moiety has attracted considerable attention from the synthetic chemistry community due to its outstanding performance in the drug design and development. By employing 4‐CzIPN as photocatalyst, a metal‐free synthetic method for gem‐difluoroalkenes is developed under blue LED irradiation. A wide range of tertiary amines and α‐trifluoromethyl alkenes are applicable in the present gem‐difluoroallylation and successfully transformed into the gem‐difluoroalkenes in good yields.
Sustainable Efficient Synthesis of Pyrrolidones from Levulinic Acid over Pd/C Catalyst
Authors: Liu Yingxin , Wang Yun , Cheng Yuran , Wei Zuojun
Published: July 2022

The synthesis of 5‐methyl‐2‐pyrrolidone through reductive amination of levulinic acid (LA) with ammonium formate (AF) as a source of both hydrogen and nitrogen over Pd/C catalyst was investigated. The effects of various reaction parameters, such as solvent, catalyst dosage, ammonium formate amount and temperature on the conversion of LA into 5‐methyl‐2‐pyrrolidone (MPD) were systematically investigated. The results showed that a MPD yield as high as 98 % was obtained in water at 180 °C for 4 h under a low metal content (0.28 mol% Pd relative to LA), which is higher than many previous reports. The Pd/C catalyst could be reused for at least 9 times with only a slight loss in activity. Meanwhile, Pd/C catalyst was efficient for the conversion of LA/ester into various N‐substituted‐5‐methyl‐2‐pyrrolidones (80–93 % yield) by using a mixture of formic acid and the corresponding primary amines.
PVC Coated Lignin/silica Composites Derived from Biomass Rice Husks as a High Performance Anode Material for Lithium Ion Batteries
Authors: Cui Xinying , Liu Li , Liu Xiaoyang , Li Yixin , He Zhongyu , Liu Liangyu , Zhang Minzhe , Zhu Yanchao , Wang Xiaofeng
Published: July 2022

Lignin, as the second most abundant natural polymer, has not been fully utilized in the industrial field due to the complex structure and functional groups. In this paper, polyvinyl chloride (PVC) coated lignin‐silica composites (PLS) with excellent cycling performance are prepared from rice husk and PVC through the method of alkali extraction and acid precipitation and mechanical mixing process. Due to the existence of functional groups on the surface of lignin, it can be closely combined with PVC to form a stable structure. The first discharge specific capacity and Coulombic efficiency of PLS is 1436 mA h g−1 and 56 %, respectively, and the reversible capacity is 720 mA h g−1 after 200 cycles at 0.1 A g−1, showing a stable cycling performance. This work promotes the application of lignin in the SiO2/C anode material of lithium ion battery, and confirms the stable combination between PVC and organic carbon.
An efficient approach to access 2,5‐disubstituted 1,3,4‐oxadiazoles by oxidation of 2‐arenoxybenzaldehyde N‐acyl hydrazones with molecular iodine
Authors: Başpınar Küçük Hatice , Alhonaish Anoud , Yıldız Tülay , Güzel Mustafa
Published: July 2022

An oxidative cyclization of 2‐arenoxybenzaldehyde N‐acyl hydrazones 3 a–o was employed to synthesize new 2,5‐disubstituted 1,3,4‐oxadiazole compounds 4 a–d, 4 f–i, 4 k–n. This method involves oxidative cyclization of 2‐arenoxybenzaldehyde N‐acyl hydrazones 3 a–o with molecular iodine mediated catalysis in which potassium carbonate served as a base. Characterization of all the synthesized novel compounds involved, proton and carbon NMR, mass spectrometry, and CHN elemental analysis. The synthesis of novel 2,5‐disubstituted 1,3,4‐oxadiazoles may display potential to provide pharmacologically important heterocyclic compounds.