bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aging spinal cord microglia become phenotypically heterogeneous and preferentially target motor neurons and their synapses
Authors: Castro Ryan W , Lopes Mikayla C , De Biase Lindsay M , Valdez Gregorio 
Published: September 2023

AbstractMicroglia have been found to acquire unique region‐dependent deleterious features with age and diseases that contribute to neuronal dysfunction and degeneration in the brain. However, it remains unknown whether microglia exhibit similar phenotypic heterogeneity in the spinal cord. Here, we performed a regional analysis of spinal cord microglia in 3‐, 16‐, 23‐, and 30‐month‐old mice. Using light and electron microscopy, we discovered that spinal cord microglia acquire an increasingly activated phenotype during the course of aging regardless of regional location. However, aging causes microglia in the ventral but not dorsal horn to lose their spatial organization. Aged ventral horn microglia also aggregate around the somata of motor neurons and increase their contacts with motor synapses, which have been shown to be lost with age. These findings suggest that microglia may affect the ability of motor neurons to receive and relay motor commands during aging. To generate additional insights about aging spinal cord microglia, we performed RNA‐sequencing on FACS‐isolated microglia from 3‐, 18‐, 22‐, and 29‐month‐old mice. We found that spinal cord microglia acquire a similar transcriptional identity as those in the brain during aging that includes altered expression of genes with roles in microglia‐neuron interactions and inflammation. By 29 months of age, spinal cord microglia exhibit additional and unique transcriptional changes known and predicted to cause senescence and to alter lysosomal and ribosomal regulation. Altogether, this work provides the foundation to target microglia to ameliorate aged‐related changes in the spinal cord, and particularly on the motor circuit.
Impact of sarcopenia on the survival of patients undergoing liver transplantation for decompensated liver cirrhosis
Authors: Zhou Da , Zhang Donghua , Zeng Chenghao , Zhang Li , Gao Xuejin , Wang Xinying 
Published: September 2023

AbstractBackgroundPatients with decompensated cirrhosis (DC) are prone to skeletal muscle loss, namely, sarcopenia, before liver transplantation (LT). While sarcopenia is reportedly associated with adverse outcomes after LT, these findings are limited owing to mixed diseases and retrospective data. We investigated the association between sarcopenia and 1‐year overall survival (OS) in patients with DC after LT and established and validated a prediction model for postoperative OS based on sarcopenia.MethodsOverall, 222 consecutive patients who underwent LT at our centre were registered between September 2020 and June 2022. Third lumbar spine skeletal muscle mass index was measured using computed tomography. Patients were divided into sarcopenia and non‐sarcopenia groups according to the skeletal muscle mass index, and baseline data and postoperative outcomes were collected, compared and analysed. The primary outcome was the 1‐year OS after LT. We established a dynamic nomogram of the OS predictive model.ResultsWe included 177 DC patients [mean (standard deviation) age, 50.2 ± 9.3 years; 52 women (29.4%)]; 73 (41.2%) had sarcopenia. The mean (standard deviation) body mass index was 22.6 ± 4.5 kg/m2, 28 (15.8%) patients had weight loss ≥5% within 6 months before admission, and the mean (standard deviation) model for end‐stage liver disease (MELD) score was 18.4 ± 7.9. Patients with sarcopenia had a longer duration of intensive care unit stay (4.1 ± 2.2 vs. 3.1 ± 1.1 days, P = 0.008), higher rate of major complications (45.2% vs. 22.1%, P = 0.001) and higher postoperative mortality (15.1% vs. 2.9%, P = 0.003) than those without sarcopenia. The median 1‐year OS after surgery was shorter in patients with sarcopenia than in those without (P < 0.001). Sarcopenia [hazard ratio (HR), 2.54; 95% confidence interval (CI), 1.54–5.63; P = 0.022], weight loss ≥5% (HR, 2.46; 95% CI, 1.39–5.09; P = 0.015) and MELD score (HR, 1.05; 95% CI, 1.01–1.09; P = 0.009) were independent risk factors associated with 1‐year OS. The area under the curve of the established dynamic nomogram was 0.774, the calibration curve showed good consistency, and analysis of the decision curve showed more clinical benefits than the MELD score alone. High‐risk patients (>102.9 points calculated using the nomogram) had a significantly reduced survival rate.ConclusionsSarcopenia is associated with adverse outcomes after LT in patients with DC. High‐risk patients should be classified by dynamic nomogram upon admission.
Mid–late Holocene palaeoclimate and biogeochemical evolution of Wular Lake, Kashmir Valley, India
Authors: Shah Rayees Ahmad , Rahman Abdur , Yadava M. G. , Kumar Sanjeev 
Published: September 2023

AbstractContinuous multiproxy data were generated to understand the mid–late Holocene palaeoenvironmental history of the Kashmir Valley and the biogeochemistry of Wular Lake, India. For this purpose, geochemical and stable isotopic analyses were carried out on sediment samples retrieved from a 160 cm long trench excavated on the eastern bank of Wular Lake located in the Union Territory of Jammu and Kashmir, India. The chronology of the sediment strata developed using 14C dating by accelerator mass spectrometry covered the last ~5600 yr
bp. Our results indicated the occurrence of an extended dry climate phase from 4600 to 3800 yr
bp, which coincided with the widely recognised Meghalayan Stage, when major civilisations like the Harappa and the Akkadian were known to collapse. The lake biogeochemistry revealed dominance of the emergent macrophytes during this stage. Another dry phase was observed between 3100 and 2200 yr
bp. This dry phase peaked at around 2900 yr
bp, coinciding with Bond Event 2. Wular Lake faced nutrient limitation due to low runoff around 2500 yr
bp caused by the persistent dry and cold climate. Geochemical signatures revealed that anthropogenic activities during the last two millennia might have significantly influenced erosion in the catchment area.
Human activities are the key driver of water erosion changes in northeastern China
Authors: Tang Qi , Hua Li , Cao Yunfei , Jiang Long , Cai Chongfa 
Published: September 2023

AbstractNortheast China is experiencing severe soil erosion, resulting in land degradation and nutrient loss. Among them, water erosion poses the greatest threat to food security. Combining various multi‐source data, we applied the modified soil erosion equation (RUSLE) to evaluate the water erosion modulus in Northeast China (1985–2021). We used the threshold segmentation and residual analysis method to quantify the relative roles of climate change and human activities on water erosion. The outcomes were as follows: (1) In recent decades, the average annual water erosion modulus in northeastern China was 804.78 t·km−2·a−1, decreasing with a slope of −11.114 t·km−2·a−1. In 24% of the study area, the erosion modulus increased significantly, mainly in grassland and farmland, due to grassland degradation and expansion of sloping cropland. In 20% of the study area, erosion modulus decreased significantly, mainly spread in forests, which was attributed to the implementation of important ecological restoration projects by the Chinese government, such as afforestation programs and returning farmland to forest. (2) During the research process, there were spatial variations in water erosion drivers in Northeast China. For areas with significant increases in erosion, 20% of the total study area were caused by anthropogenic factors, and 3% were attributed to natural factors. For areas where erosion had significantly improved, 18% of the total study area was attributed to ecological restoration, and 2% to natural factors. (3) Based on the results of the study, ecological restoration of forests and grasses, management of sloping cropland, and conservation tillage were recommended to reduce soil erosion in Northeast China.
Six‐probe scintillator dosimeter for treatment verification in HDR‐brachytherapy
Authors: Gonod Mathieu , Suarez Miguel Angel , Avila Carlos Chacon , Karakhanyan Vage , Eustache Clément , Laskri Samir , Crouzilles Julien , Vinchant Jean‐François , Aubignac Léone , Grosjean Thierry 
Published: September 2023

AbstractBackgroundIn vivo dosimetry (IVD) is gaining interest for treatment delivery verification in HDR‐brachytherapy. Time resolved methods, including source tracking, have the ability both to detect treatment errors in real time and to minimize experimental uncertainties. Multiprobe IVD architectures holds promise for simultaneous dose determinations at the targeted tumor and surrounding healthy tissues while enhancing measurement accuracy. However, most of the multiprobe dosimeters developed so far either suffer from compactness issues or rely on complex data post‐treatment.PurposeWe introduce a novel concept of a compact multiprobe scintillator detector and demonstrate its applicability in HDR‐brachytherapy. Our fabricated seven‐fiber probing system is sufficiently narrow to be inserted in a brachytherapy needle or in a catheter.MethodsOur multiprobe detection system results from the parallel implementation of six miniaturized inorganic Gd2O2S:Tb scintillator detectors at the end of a bundle of seven fibers, one fiber is kept bare to assess the stem effect. The resulting system, which is narrower than 320 microns, is tested with a MicroSelectron 9.14 Ci Ir‐192 HDR afterloader, in a water phantom. The detection signals from all six probes are simultaneously read with a sCMOS camera (at a rate of 0.06 s). The camera is coupled to a chromatic filter to cancel Cerenkov signal induced within the fibers upon exposure. By implementing an aperiodic array of six scintillating cells along the bundle axis, we first determine the range of inter‐probe spacings leading to optimal source tracking accuracy (first tracking method). Then, three different source tracking algorithms involving all the scintillating probes are tested and compared. In each of these four methods, dwell positions are assessed from dose measurements and compared to the treatment plan. Dwell time is also determined and compared to the treatment plan.ResultsThe optimum inter‐probe spacing for an accurate source tracking ranges from 15 to 35 mm. The optimum detection algorithm consists of adding the readout signals from all detector probes. In that case, the error to the planned dwell positions is of 0.01 ± 0.14 mm and 0.02 ± 0.29 mm at spacings between the source and detector axes of 5.5 and 40 mm, respectively. Using this approach, the average deviations to the expected dwell time are of s and s, at spacings between source and probe axes of 5.5 and 20 mm, respectively.ConclusionsOur six‐probe Gd2O2S:Tb dosimeter coupled to a sCMOS camera can perform time‐resolved treatment verification in HDR brachytherapy. This detection system of high spatial and temporal resolutions (0.25 mm and 0.06 s, respectively) provides a precise information on the treatment delivery via a dwell time and position verification of unmatched accuracy.
Synthetic modelling of railway trackbed for improved understanding of ground penetrating radar responses due to varying conditions
Authors: Couchman Matthew John , Barrett Brian , Eriksen Asger 
Published: September 2023

AbstractGround penetrating radar (GPR) is a commonly used tool for railway trackbed inspection due to its ability to collect information about subsurface materials at high resolution and high speed. Although GPR recording systems allow for the collection of vast quantities of data (hundreds of kilometres per day), accurate ground truth information is difficult to obtain. Models of trackbed can be used to generate synthetic radargrams to provide a better understanding and predictability of GPR responses to a wide range of trackbed conditions. In this research, we produced models of ballast using randomly shaped 3D particles, with a range of particle size distributions to represent various stages of ballast breakdown. Additionally, void spaces are partially filled with a constant dielectric material to represent ballast contamination. We used gprMax to simulate the GPR response for a 2 GHz horn antenna over the trackbed models. These simulations resulted in radargrams that are visually indistinct from real recorded data in known conditions. These radargrams, along with their formative models, have provided valuable insights into how variations in trackbed conditions can impact GPR data.
Algorithmic realization of exact three‐point difference scheme for singular Sturm–Liouville problem
Authors: Khomenko Nadiya , Kutniv Myroslav 
Published: September 2023

AbstractA new algorithmic realization of exact three‐point difference schemes for a class of singular Sturm–Liouville problems is presented. It is shown that to compute the coefficients of the exact scheme in an arbitrary grid node, it is necessary to solve two auxiliary initial value problems for the second order linear ordinary differential equations: one problem on the interval (forward) and one problem on the interval (backward). Finally, the coefficient stability of the exact three‐point difference scheme is proved.
Increased expression of phosphodiesterase 4 in activated hepatic stellate cells promotes cytoskeleton remodeling and cell migration
Authors: Elnagdy Mohamed , Wang Yali , Rodriguez Walter , Zhang JingWen , Bauer Philip , Wilkey Daniel W , Merchant Michael , Pan Jianmin , Farooqui Zainab , Cannon Robert , Rai Shesh , Maldonado Claudio , Barve Shirish , McClain Craig J , Gobejishvili Leila 
Published: September 2023

AbstractActivation and transdifferentiation of hepatic stellate cells (HSC) into migratory myofibroblasts is a key process in liver fibrogenesis. Cell migration requires an active remodeling of the cytoskeleton, which is a tightly regulated process coordinated by Rho‐specific guanine nucleotide exchange factors (GEFs) and the Rho family of small GTPases. Rho‐associated kinase (ROCK) promotes assembly of focal adhesions and actin stress fibers by regulating cytoskeleton organization. GEF exchange protein directly activated by cAMP 1 (EPAC1) has been implicated in modulating TGFβ1 and Rho signaling; however, its role in HSC migration has never been examined. The aim of this study was to evaluate the role of cAMP‐degrading phosphodiesterase 4 (PDE4) enzymes in regulating EPAC1 signaling, HSC migration, and fibrogenesis. We show that PDE4 protein expression is increased in activated HSCs expressing alpha smooth muscle actin and active myosin light chain (MLC) in fibrotic tissues of human nonalcoholic steatohepatitis cirrhosis livers and mouse livers exposed to carbon tetrachloride. In human livers, TGFβ1 levels were highly correlated with PDE4 expression. TGFβ1 treatment of LX2 HSCs decreased levels of cAMP and EPAC1 and increased PDE4D expression. PDE4 specific inhibitor, rolipram, and an EPAC‐specific agonist decreased TGFβ1‐mediated cell migration in vitro. In vivo, targeted delivery of rolipram to the liver prevented fibrogenesis and collagen deposition and decreased the expression of several fibrosis‐related genes, and HSC activation. Proteomic analysis of mouse liver tissues identified the regulation of actin cytoskeleton by the kinase effectors of Rho GTPases as a major pathway impacted by rolipram. Western blot analyses confirmed that PDE4 inhibition decreased active MLC and endothelin 1 levels, key proteins involved in cytoskeleton remodeling and contractility. The current study, for the first time, demonstrates that PDE4 enzymes are expressed in hepatic myofibroblasts and promote cytoskeleton remodeling and HSC migration. © 2023 The Pathological Society of Great Britain and Ireland.
Perceptions of chemotherapy calendar creation among US pediatric oncologists
Authors: Mueller Emily L. , Cochrane Anneli R. , Carroll Aaron E. 
Published: September 2023

AbstractBackgroundAn effective chemotherapy calendar system between the clinician and the patient/caregiver can improve patient‐centered outcomes. There is lack of research on how chemotherapy calendars are created and what aspects are important to pediatric oncology physicians.ProcedureIn an online survey of pediatric oncology physicians, we evaluated institutional practices, perceptions of chemotherapy calendar creation, and desires for future tools. A total of 220 survey participants provided data (10.4% participant response rate) from 123 institutions (53.5% represented institutions).ResultsParticipants indicated that 72% always or most of the time their institution provides a chemotherapy calendar, most commonly at the start of a new cycle (90%) or with a dosing change (68%). Factors such as the health literacy of the family, prior nonadherence, type of cancer, and desire of the family affected the creation decision. Advanced practice providers (45%) or nurse coordinator/navigators (43%) were most likely to create the chemotherapy calendar. No significant difference was found between the likelihood of creating a chemotherapy calendar and institutional size (p = .09) or physician years in practice (p = .26). Approximately 95% of participants indicated chemotherapy calendar creation software that improved ease and efficiency would be moderately to extremely useful.ConclusionFuture efforts should focus on co‐design of an efficient and effective chemotherapy calendar by engaging with nursing and advanced practice providers along with caregivers of children with cancer.
Preparation and properties of polyetherimide fibers based on the synergistic effect of carbon nanotubes and ionic liquids
Authors: Ke Fuyou , Yang Xiao , Zhang Meirong , Chen Ye , Wang Huaping 
Published: September 2023

AbstractPolyetherimide (PEI) has been widely applied in the form of plastics, films, and foam materials. But PEI fiber is confronted with some challenges, such as high melt viscosity and high spinning temperature during the spinning process, poor mechanical properties because of its amorphous structure. In this study, ionic liquids (ILs) and carbon nanotubes (CNTs) were used to prepare PEI composite fibers (PEI/CNT‐IL) successfully, which were further characterized by scanning electron microscope (SEM), Raman spectra, differential scanning calorimetry, dynamic mechanical analysis, thermalgravimetric analysis, mechanical property, and conductivity measurements. IL showed a plasticizing effect to reduce the processing temperature of PEI and SEM images showed that CNTs were uniformly dispersed in the PEI matrix by the assistance of IL. The synergistic effect of CNT and IL thus improved the tensile strength and antistatic properties of PEI fibers. When the contents of CNT and IL were 0.5 and 1.0 wt%, respectively, the optimal properties were obtained. PEI/CNT‐IL fibers exhibited a maximum tensile strength of 2.0 cN/dtex with the elongation at break being 90%, and the enhanced electrical conductivity of 10−5 S·cm−1, which was increased by 13 orders of magnitude compared to that of pristine PEI fiber.Highlights
PEI composite fibers were prepared via melt spinning with the assistance of IL and CNT.
IL can effectively disperse CNT and plasticize PEI to reduce the processing temperature.
The synergistic effect of CNT and IL has improved the tensile strength and antistatic properties of PEI fibers.
Simulation of double resonant excitation of ions in an asymmetric linear ion trap mass analyzer
Authors: Xu Kai , Qiu Jun Wei , Zhang Tao , Zhu Hui Jun , Zhang Shuo , Lu Xin Xin , Li Xiao Xu 
Published: September 2023

RationaleImproving the analytical performance of linear ion traps (LITs) is crucial for the advancement of high‐performance LIT mass spectrometers. In this study, a double resonant excitation method was employed in an asymmetric LIT to achieve high ion unidirectional ejection efficiency and enhanced mass resolution.MethodsThe asymmetric trapping field was generated by stretching one x electrode with a distance α. The double resonant excitation was achieved by applying an alternating voltage out of phase and a supplementary alternating voltage in phase to the x and y electrode pairs of the LIT, respectively. Numerical simulations of ion trajectories were performed to validate the effectiveness of this method.ResultsThe mass resolution of the asymmetric LIT with double resonant excitation could be improved to ~3800, which was over two times compared to that with only dipolar resonant excitation, while both reached ~90% in ion unidirectional ejection efficiency.ConclusionsBy employing the double resonant excitation method, the mass resolution could be improved significantly in the asymmetric LIT, while maintaining a considerably high ion unidirectional ejection efficiency. This method might provide a general solution for enhancing ion detection efficiency and mass resolution of LIT mass spectrometers.
Efficient Synthesis of Quinoxalines by I2/AgNO3 Co‐Promoted One‐Pot Annulation of Alkynes with 1,2‐Arylenediamines
Authors: Zhang Wei , Yang Xuerui , Cao Zhongzhong , Min Xin , Zhou Hang , Zhong Jialong , Gong Ting , Wang Lidan , Huang Qingchun , Yang Wen 
Published: September 2023

AbstractAn efficient I2/AgNO3 co‐promoted one‐pot annulation of alkynes with 1,2‐arylenediamines into quinoxalines is reported. The reaction proceeded smoothly under mild conditions and rapidly generated quinoxalines (37 examples) in good to excellent yields (up to 83 %) with a good tolerance of functional groups. Moreover, π‐conjugated polycyclic quinoxaline derivatives could also be successfully synthesized by this one‐pot strategy. Furthermore, a gram‐scale reaction of the one‐pot reaction is also investigated. Finally, a plausible mechanism for the one‐pot reaction is proposed.
Transition Metal Catalyst Free and Single‐Step Synthesis of Significant Thiosemicarbazones via Oxidative Coupling Strategy
Authors: Dharani S. , Nithya V. , Indumathy R. , Kalaiarasi G. 
Published: September 2023

AbstractThe efficacy and selectivity of the transition metal‐free catalysis have been emphasized in constructing thiosemicarbazone derivatives from the dehydrogenative coupling of alcohols and thiosemicarbazides under aerobic conditions. A broad spectrum of thiosemicarbazones was obtained in good‐to‐excellent yields up to 90 %, with water as the only by‐product. The catalytic synthesis worked in an atom‐economical fashion in the absence of any oxidant with only 1 mmol of the base loading per mmol of the substrates. Further, the impact of different temperatures, solvents, bases, and base loading of the coupling reaction has been explored. A probable pathway that involves the generation of an aldehyde intermediate to thiosemicarbazones, which releases only water has been proposed.
Carbon‐Sulfur Bond Formation via Ipso Nucleophilic Substitution of Electron‐Deficient Benzenesulfonic Acid with Thiol
Authors: Mondal Sandip , Mukherjee Poulami , Paul Ankita , Sikdar Asmita , Mandal Bhubaneswar 
Published: September 2023

AbstractDeveloping green and convenient strategies for constructing C−S bonds is attractive, as it is indispensable for numerous essential biological and pharmaceutical compound syntheses. Herein, an efficient, cost‐effective method for synthesizing 2,4‐dinitroaryl thioether derivatives is achieved by ipso nucleophilic substitution of an aromatic sulfonic acid group by thiol to construct a new C−S bond. This methodology neither requires the assistance of any transition metal catalyst nor harsh reaction conditions. Such thioether formation from aryl sulfonic acids is new.