bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid biosynthesis of biosurfactants by Bacillus tequilensisSL9 isolated from oily sludge: Characterization, optimization, and potential applications
Authors: Su Han , Wang Yujing , Chen Xin , Zhang Mengjun , Li Chunyan , Zhao Feng 
Published: September 2023

AbstractThe demand of biosurfactants is increasing. It is of great significance to obtain nonpathogenic and high‐yielding microorganisms for the industrial‐scale production of biosurfactants. A biosurfactant‐producing strain SL9 was isolated from oily sludge. It was identified as Bacillus tequilensis based on colonial morphology and 16S rDNA sequence analysis. The biosurfactants produced by strain SL9 was extracted by modified acid precipitation method. A mixture of C12, C13, C14 and C15 surfactin homologues was detected based on HPLC–MS analysis. The optimum production of biosurfactants occurs at pH 7.0 and in the presence of 1.0 g/L NaCl. The optimal carbon source and nitrogen source were 40.0 g/L sucrose and 4.0 g/L NaNO3, respectively. The maximum yield of biosurfactants from strain SL9 was up to 1332.68 mg/L. Interestingly, B. tequilensis SL9 can rapidly synthesize biosurfactants with a yield of 739.36 mg/L in 12 h. The extracted biosurfactants reduced the surface tension of water from 72.1 to 27.5 mN/m with a CMC of 33 mg/L. The biosurfactants can also emulsify paraffin with a EI24 value of 57.58% and keep this good emulsifying activity after 96 h. The produced biosurfactants showed antimicrobial activities against Staphylococcus aureus, Cladosporium sp. and Alternaria sp. with inhibitory rate of 75.67%, 59.07% and 22.91%, respectively. The isolated strain B. tequilensis SL9 can be a nonpathogenic producer for rapid biosynthesis of biosurfactants with a relative high yield. Strain SL9 and its biosurfactant products are promising for application in the oil exploration, bioremediation, agricultural biocontrol, and pharmaceutical industries.
Properties of Cross‐Linked Poly‐l‐lysine Hydrogels across the Random Coil–Helix Transition
Authors: Wilcox Kathryn G. , Grinevich Alexandra , Linscott Adam , Singh Abhinendra , Morozova Svetlana 
Published: September 2023

AbstractHydrogels are key components of biological tissues and have applications in biomedicine and commercial industry. Many biological tissues are known to strain harden due to the semiflexible nature of the chains. Here, the mechancial properties of poly‐l‐lysine (PLL) hydrogels, whose network chains undergo a random coil–helix transition, are studied as a function of the polypeptide's structural changes. PLL is cross‐linked with poly(ethylene glycol)diglycidyl ether at cross‐link percents ranging from 3% to 6%. The conformation change and mechanical properties are investigated with circular dichroism and small and large amplitude oscillatory shear rheology, respectively. As a function of pH at low cross‐link percents, a transition from strain softening to strain hardening is observed as the network chains become helical that is similar to the behavior of biological filamentous gels and consistent with recent theoretical descriptions of network strain hardening. At higher cross‐link densities, the hydrogels become brittle due to stress concentration in inhomogeneous locations in the network, which is studied with dynamic light scattering. Overall, the random coil–helix transition has a significant effect on the nonlinear mechanical properties of PLL hydrogels. By understanding the hydrogel structure and response to environmental changes, their potential can be expanded as functional biomedical materials.
Acquisition of a novel conjugative multidrug‐resistant hypervirulent plasmid leads to hypervirulence in clinical carbapenem‐resistant Klebsiella pneumoniae strains
Authors: Li Gong , Jia Ling , Wan Lei , Xia Lijuan , Gao Ang , Yang Runshi , Sun Ruanyang , Wang Minge , Du Juan , Lian Xinlei , Zhang Rongmin , Fang Liangxing , Liao Xiaoping , Liu Yahong , Liu Bao‐Tao , Sun Jian 
Published: September 2023

AbstractThe co‐occurrence of plasmid‐mediated multidrug resistance and hypervirulence in epidemic carbapenem‐resistant Klebsiella pneumoniae has emerged as a global public health issue. In this study, an ST23 carbapenem‐resistant hypervirulent K. pneumoniae (CR‐HvKP) strain VH1‐2 was identified from cucumber in China and harbored a novel hybrid plasmid pVH1‐2‐VIR. The plasmid pVH1‐2‐VIR carrying both virulence and multidrug‐resistance (MDR) genes was likely generated through the recombination of a virulence plasmid and an IncFIIK conjugative MDR plasmid in clinical ST23 18622 isolated from a sputum sample. The plasmid pVH1‐2‐VIR exhibited the capacity for transfer to the clinical ST11 carbapenem‐resistant K. pneumoniae (CRKP) strain via conjugation assay. Acquisition of pVH1‐2‐VIR plasmid directly converted a CRKP into CR‐HvKP strain characterized by hypermucoviscosity, heightened virulence for Galleria mellonella larvae, and increased colonization ability in the mouse intestine. The emergence of such a hybrid plasmid may expedite the spread of CR‐HvKP strains, posing a significant risk to human health.
Design of slotted split‐ring resonator‐based sensor for characterization of oil samples
Authors: Logeswaran J. , Boopathi Rani R. 
Published: September 2023

AbstractThe paper aims to utilize a metamaterial (MTM) structure, specifically the slotted plus‐shapes within a square split‐ring resonator, to analyze the characteristics of the reused oil and also used to classify different oil samples. The proposed MTM structure is designed to operate within the X‐band frequency range of 8–12.4 GHz. The MTM structure is simulated using the high‐frequency EM simulation tool, and the MTM properties are extracted using standard equations. The negative permittivity and permeability characteristics of the proposed MTM structure in the X‐band are studied to verify its suitability for X‐band applications. A sample container is designed to hold the oil samples, and the experiments were carried out using an X‐band waveguide setup with Vector Network Analyzer. The results were analyzed and presented in brief to examine reused oil and classify different oils.
HDAC4 regulates the proliferation, migration, and invasion of trophoblasts in pre‐eclampsia through the miR‐134‐5p/FOXM1 axis
Authors: Xu Yanli , Kang Xiaodi , Jiang Hongli , Liu Huafang , Wang Wenjing 
Published: September 2023

AbstractEpigenetics, including histone modifications and noncoding RNAs, affects abnormal placental function in pre‐eclampsia (PE). This study was conducted to explore the role of histone deacetylase 4 (HDAC4) in trophoblast invasion and migration. The expression levels of HDAC4, microRNA (miR)‐134‐5p, and forkhead box protein M1 (FOXM1) in placentas from PE patients and healthy controls and their correlations were examined. HTR8/SVneo cells were cultured and underwent gene intervention. Then, trophoblast proliferation, invasion, and migration were evaluated by 5‐ethynyl‐2ʹdeoxyuridine, Transwell, and scratch assays. The enrichments of HDAC4 and acetylated histone H3 at lysine 9 (H3K9Ac) on the miR‐134‐5p promoter were quantified by chromatin immunoprecipitation. The binding of miR‐134‐5p to FOXM1 was analyzed by dual‐luciferase assay. HDAC4 and FOXM1 were downregulated while miR‐134‐5p was upregulated in PE placentas. HDAC4 downregulation impaired trophoblast proliferation, invasion, and migration while HDAC4 overexpression played the opposite role. Mechanically, HDAC4 deacetylated H3K9Ac to repress miR‐134‐5p expression by erasing H3K9Ac, reduced the binding of miR‐134‐5p to FOXM1, and then promoted FOXM1 transcription. miR‐134‐5p overexpression or FOXM1 downregulation abrogated the promotive role of HDAC overexpression in trophoblast invasion and migration. Our study unraveled a novel mechanism of trophoblast proliferation, invasion, and migration and proposed that HDAC4 may be a promising target for the treatment of PE.
Numerical simulation of fluid‐particle interaction in geomechanics using an extended CFD‐DEM approach with a super‐quadric model of non‐spherical particles
Authors: Wang Yin , Yang Yefeng , Yang Han , Pang Ziyi 
Published: September 2023

AbstractThis paper presents a numerical study of the effects of the particle's shape and its interaction with surrounding fluid on the mechanism of sandpiles formation in air and water, respectively. This study is motivated by the fact that seabed sediments are predominantly deposited in water and consist of non‐spherical particles. In our study, a non‐linear contact model is employed in the Discrete Element Method. At the same time, the void fraction model and drag force model of non‐spherical particles with sharp corners are further improved. Based on the above two advancements, an extended computational fluid dynamics‐discrete element method (CFD‐DEM) approach coupled with the super‐quadric model is developed. It can accurately simulate multi‐collision and interlocking characteristics between non‐spherical particles, as well as particle‐fluid interactions. Subsequently, the validation and applicability of this extended CFD‐DEM approach are proved by comparing the results of experiment and theory models for various cases. The discrepancies induced by particle shape are revealed in terms of repose angles, porosity, and stress distribution. This is due to non‐spherical particles exhibiting a significant occlusal interlocking effect, which enhances inter‐particle friction. Additionally, the influence of ambient water is non‐negligible, as it supports a portion of the upward particle weight during the process of sandpiles formation. The above findings can be substantiated by analyzing the fabric structure of sandpiles. Such coupling of macro‐ with micro‐scale insights into the fundamental geomechanical issues will further extend to wide fields, particularly sea‐water‐flow‐induced seabed instability.
High‐resolution proton metabolic mapping of the human brain at 7 T using free induction decay rosette spectroscopic imaging
Authors: Mahmud Sultan Z. , Denney Thomas S. , Bashir Adil 
Published: September 2023

AbstractMagnetic resonance spectroscopic imaging (MRSI) provides information about the spatial distribution of metabolites in the brain. These metabolite maps can be valuable in diagnosing central nervous system pathology. However, MRSI generally suffers from a long acquisition time, poor spatial resolution, and a low metabolite signal‐to‐noise ratio (SNR). Ultrahigh field strengths (≥ 7 T) can benefit MRSI with an improved SNR and allow high‐resolution metabolic mapping. Non‐Cartesian spatial‐spectral encoding techniques, such as rosette spectroscopic imaging, can efficiently sample spatial and temporal domains, which significantly reduces the imaging time and enables high‐resolution metabolic mapping in a clinically relevant scan time. In the current study, high‐resolution (in‐plane resolution of 2 × 2 mm2) mapping of proton (1H) metabolites in the human brain at 7 T, is demonstrated. Five healthy subjects participated in the study. Using a time‐efficient rosette trajectory and short TR/TE free induction decay MRSI, high‐resolution maps of 1H metabolites were obtained in a clinically relevant imaging time (6 min). Suppression of the water signal was achieved with an optimized water suppression enhanced through T1 effects approach and lipid removal was performed using L2‐regularization in the postprocessing. Spatial distributions of N‐acetyl‐aspartate, total choline, creatine, N‐acetyl‐aspartyl glutamate, myo‐inositol, and glutamate were generated with Cramer–Rao lower bounds of less than 20%.
Association between occupational stress and mental health of nurses during the COVID‐19 pandemic: A cross‐sectional research
Authors: Wu Huiying , Qi Kewen , Luan Bonan , Liu Zhengwen , Zhao Qingyun 
Published: September 2023

AbstractAimThis study is aimed to explore the association between the occupational stress and mental health among Chinese nurses during the COVID‐19 pandemic.DesignCross‐sectional study.MethodsThere were 2913 nurse participants enrolled in the study. Demographic characteristics and other data were measured by a self‐reported questionnaire. Occupational stress was measured by using the effort–reward imbalance (ERI) questionnaire. Mental health was measured by the Patient Health Questionnaire‐9 and the General Anxiety Disorder‐7.ResultsAmong the participants, 14.32% (417) experienced ERI; 8.1% (237) and 7.2% (210) reported depressive and anxiety symptoms, respectively. Compared with a reference group at the lowest quartile of the ERI, participants in the highest quartile had an adjusted odds ratio (OR) (95% CI) of 11.17 (4.42, 28.25) for incident depressive symptoms. For anxiety symptoms, the OR and 95% CI was 2.28 (1.21, 4.29). The ERI was shown to have a detrimental effect on mental health, especially depressive symptoms.
Exploring the barriers to Registered Nurses undertaking clinical teaching in clinical settings: A qualitative descriptive study
Authors: Hoebes Riana Rolinda , Ashipala Daniel Opotamutale 
Published: September 2023

AbstractAimThe study aimed to explore and describe the barriers affecting Registered Nurses in undertaking clinical teaching in clinical settings. The exploration was based on the experiences of Registered Nurses at a selected teaching hospital in Namibia. The researcher intended to identify strategies that could be used to mitigate the negative effects of barriers to effective clinical teaching.DesignA qualitative explorative, descriptive and contextual research design was used.MethodsPurposive sampling was used to select 16 participants. Data were collected through in‐depth, semi‐structured interviews, which were audio‐recorded and transcribed verbatim. Data were analysed using thematic analysis.ResultsClinical teaching is negatively affected by several barriers that hamper clinical teaching and nursing students' learning outcomes. Seven main themes were identified: (1) participants' understanding of clinical teaching; (2) organizational barriers; (3) patient barriers; (4) Registered Nurse barriers; (5) student barriers; (6) training institution barriers; and (7) strategies to mitigate barriers to clinical teaching.ConclusionThe findings revealed that several barriers negatively affect clinical nursing education and hamper the clinical teaching and learning of nursing students.Patient or Public ContributionThis study may assist in the development of targeted interventions that address the barriers that hinder clinical teaching at teaching hospitals. Additionally, this study could assist in improving the health care that is provided by nursing students to patients. The findings may assist with improved quality by reducing nursing students' theory‐practice gap and by promoting collaboration between Registered Nurses and nurse educators in clinical settings.
Production and purification of fumonisins from a stirred jar fermenter
Authors: Miller J. David , Savard Marc E. , Rapior Sylvie 
Published: September 2023

AbstractThe production, isolation and purification of fumonisins from 10 litre liquid cultures are described. Measurements of sucrose, fructose and glucose consumption, oxygen demand, dry weight increase, CO2, and fumonisin production were taken every 48 hours. The specific productivity of fumonisins was found to be similar to that reported for com cultures but purification was much simpler, yielding an 89% recovery. The method developed for the purification of fumonisins from liquid culture was also applied to a corn culture, resulting in a 70.1 % recovery.
Oromandibular dystonia induced by olanzapine and mirtazapine: A case report
Authors: Umezaki Yojiro , Egashira Rui , Motomura Haruhiko , Naito Toru 
Published: September 2023

AbstractBackgroundDystonia has been reported as an adverse effect of antipsychotic medications; however, dentists rarely detect the symptoms because of the complexity of complaints.Case PresentationA 74‐year‐old woman presented with an open bite and jaw pain. She reported a history of depression and was being treated with medication including olanzapine. We diagnosed the patient with oromandibular dystonia. Her psychiatrist withdrew olanzapine treatment following consultation, and the open bite and jaw pain were resolved.ConclusionDentists should consider oromandibular dystonia when a patient taking antipsychotic medication complains of an open bite. Irreversible procedures should be avoided in these patients.
Study the effect of different fillers on the performance of ethylene propylene diene monomer rubber‐based thermal shielding materials
Authors: Mosa M. , Mokhtar M. , Fouda Hany , Gobara Mohamed 
Published: September 2023

AbstractPolymeric composites are becoming increasingly popular materials due to their wide range of uses in heat shielding materials for solid rocket motors and aerospace applications. Novel polymeric composites are prepared and evaluated containing chopped carbon fibers, glass fibers (GF), and basalt fibers (BF), besides, recently used fillers such as Kevlar fibers (KF), and fumed silica (FS) to study their effects on the mechanical, thermal, and ablative properties of the ethylene propylene diene monomer (EPDM) hybrid composite. Mechanical, chemical, thermal, and ablative tests are performed to show the performance of the prepared polymeric composites. Experimental investigations have shown that the addition of GF to the EPDM matrix has a great influence on raising the tensile strength to 6.570 MPa. By incorporating KFs into EPDM, a solid char layer is formed during ablation, resulting in the best ablative performance with a decrease in the ablation rate of 73%, while the addition of FS, and BF to EPDM gives the best thermal stability results with total weight loss of 80.34%, and 81.77%, respectively.
Hourglass, a rapid analysis framework for heterogeneous bioimaging data, identifies sex disparity in IL‐6/STAT3‐associated immune phenotypes in pancreatic cancer
Authors: Aliar Kazeera , Waterhouse Henry R , Vyas Foram , Krebs Niklas , Zhang Bowen , Poulton Emily , Chan Nathan , Gonzalez Ricardo , Jang Gun Ho , Bronsert Peter , Fischer Sandra E , Gallinger Steven , Grünwald Barbara T , Khokha Rama 
Published: September 2023

AbstractIntegration and mining of bioimaging data remains a challenge and lags behind the rapidly expanding digital pathology field. We introduce Hourglass, an open‐access analytical framework that streamlines biology‐driven visualization, interrogation, and statistical assessment of multiparametric datasets. Cognizant of tissue and clinical heterogeneity, Hourglass systematically organizes observations across spatial and global levels and within patient subgroups. Applied to an extensive bioimaging dataset, Hourglass promptly consolidated a breadth of known interleukin‐6 (IL‐6) functions via its downstream effector STAT3 and uncovered a so‐far unknown sexual dimorphism in the IL‐6/STAT3‐linked intratumoral T‐cell response in human pancreatic cancer. As an R package and cross‐platform application, Hourglass facilitates knowledge extraction from multi‐layered bioimaging datasets for users with or without computational proficiency and provides unique and widely accessible analytical means to harness insights hidden within heterogeneous tissues at the sample and patient level. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.
Proton diffusion in PAM hydrogels
Authors: Chen Fan , Ren Jie , Xiang Xu 
Published: September 2023

AbstractHydrogels are widely used in the field of biomedicine because of their excellent biocompatibility. In most cases, the pH range applicable to drugs is limited, so it is meaningful to study the diffusion of protons in hydrogels. In this work, the diffusion rate of protons in hydrogels was monitored by a self‐made device, and the factors affecting the diffusion rate of protons were studied. The self‐made device consists of a supply chamber and a receiving chamber with a piece of hydrogel sandwiching between them. It was found that the thickness of hydrogel had a great influence on proton diffusion. The thicker the hydrogel is, the slower the proton diffusion rate is. At the same time, the diffusion coefficient of protons in PAM hydrogel was calculated to be 1.28 ± 0.09 × 10−5 cm2/s (HCl, 25°C). The diffusion coefficient is a function of temperature, and its value increases with the increase in temperature. The effect of the solid content of hydrogel on proton diffusion was also considered, but in the range of solid content 1.81%–10.07%, the proton diffusion rate was almost unaffected. Moreover, anions also have a decisive effect on proton diffusion, with smaller anions leading to faster proton diffusion in the hydrogel.
High‐performance vitrimer films containing acylhydrazone dynamic covalent bonds
Authors: Zhao Yanna , Huang Yuqing , Hou Wentong , Zhang Ting , Zhang Yingying , Wang Yuqi , Bai Xiaowei 
Published: September 2023

AbstractVitrimer films containing acylhydrazone bonds are synthesized in two steps. Bio‐based vanillin and adipate dihydrazide are used to prepare diols containing acylhydrazone bonds in one step, which are introduced into the reaction system of vitrimer to obtain the final films. The process is concise and easy to operate. By utilizing the rigid structure of vitrimer films and introducing dynamic acylhydrazone bonds, the obtained vitrimer films exhibit strong mechanical strength (maximum tensile strength of 27.10 MPa and maintaining up to 185.52% of the original breaking strength), excellent self‐healing property (tensile strength of 26.26 MPa after 12 h of primary self‐healing and 5.24 MPa after 12 h of secondary self‐healing), and rapid shape memory property (recovery time of about 2 min), strong acid and alkali resistance (not dissolved within 24 h), good thermal stability (no decomposition occurs below 160 °C), and high storage modulus (reaches 1087 MPa). These comprehensive benefits yield a certain reference for the preparation of vitrimer materials with prime properties.
Molecular mass engineering for filaments in material extrusion additive manufacture
Authors: Yost Sierra F. , Pester Christian W. , Vogt Bryan D. 
Published: September 2023

Abstract3D printing of thermoplastics through local melting and deposition via material extrusion additive manufacturing provides a simple route to the near net‐shape manufacture of complex objects. However, the mechanical properties resulting from these 3D printed structures tend to be inferior when compared to traditionally manufactured thermoplastics. These unfavorable characteristics are generally attributed to the structure of the interface between printed roads. Here, we illustrate how the molecular mass distribution for a model thermoplastic, poly(methyl methacrylate) (PMMA), can be tuned to enhance the Young's modulus of 3D printed plastics. Engineering the molecular mass distribution alters the entanglement density, which controls the strength of the PMMA in the solid state and the chain diffusion in the melt. Increasing the low molecular mass tail increases Young's modulus and ultimate tensile strength of the printed parts. These changes in mechanical properties are comparable to more complex routes previously reported involving new chemistry or nanoparticles to enhance the mechanical performance of 3D printed thermoplastics. Controlling the molecular mass distribution provides a simple route to improve the performance in 3D printing of thermoplastics that can be as effective as more complex approaches.