bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential Roles of Toll-Like Receptors 2 and 4 in In Vitro Responses of Macrophages toLegionella pneumophila
Authors: Akamine Morikazu , Higa Futoshi , Arakaki Noriko , Kawakami Kazuyoshi , Takeda Kiyoshi , Akira Shizuo , Saito Atsushi 
Published: December 2004

ABSTRACTThe role of Toll-like receptors (TLRs) in innate immunity toLegionella pneumophila, a gram-negative facultative intracellular bacterium, was studied by using bone marrow-derived macrophages and dendritic cells from TLR2-deficient (TLR2−/−), TLR4−/−, and wild-type (WT) littermate (C57BL/6 × 129Sv) mice. Intracellular growth ofL. pneumophilawas enhanced within TLR2−/−macrophages compared to WT and TLR4−/−macrophages. There was no difference in the bacterial growth within dendritic cells from WT and TLR-deficient mice. Production of interleukin-12p40 (IL-12p40) and IL-10 after infection withL. pneumophilawas attenuated in TLR2−/−macrophages compared to WT and TLR4−/−macrophages. Induction of IL-12p40, IL-10, and tumor necrosis factor alpha secretion from macrophages by theL. pneumophila dotOmutant, which cannot multiply within macrophages, and heat-killed bacteria, was similar to that caused by a viable virulent strain. There was no difference between the WT and its mutants in susceptibility to the cytopathic effect of bacteria. AnL. pneumophilasonicated lysate induced IL-12p40 production by macrophages, but that of TLR2−/−macrophages was significantly lower than those of WT and TLR4−/−macrophages. Treatment ofL. pneumophilasonicated lysate with proteinase K and heating did not abolish TLR2-dependent IL-12p40 production. Our results show that TLR2, but not TLR4, is involved in murine innate immunity againstL. pneumophila, although other TLRs may also contribute to innate immunity against this organism.
Contribution of the
Helicobacter pylori
Thiol Peroxidase Bacterioferritin Comigratory Protein to Oxidative Stress Resistance and Host Colonization
Authors: Wang Ge , Olczak Adriana A. , Walton James P. , Maier Robert J. 
Published: December 2004

ABSTRACT

Peroxiredoxins, the enzymes that catalyze the reduction of hydrogen peroxide and organic hydroperoxides, are ubiquitous proteins that protect organisms from damage by reactive oxygen species.
Helicobacter pylori
contains three members of the peroxiredoxin family: AhpC (alkyl hydroperoxide reductase), Tpx (thiol-specific peroxidase), and bacterioferritin comigratory protein (BCP). In this study, we characterized
H. pylori bcp
mutant strains and wild-type BCP. Compared to the parent strain and the
ahpC
mutant strain, the
bcp
mutant showed moderate sensitivity to the superoxide-generating agent paraquat and to organic hydroperoxides. Upon exposure of 10
8
cells to air for 10 h, 10
6
wild-type cells survived but none of the 10
8
bcp
mutant cells were recovered. Introduction of an intact
bcp
gene at an unrelated locus in the
bcp
strain restored the wild-type-like oxidative stress resistance phenotype. Purified BCP was shown to be a thiol peroxidase that depends on the reducing activity of thioredoxin and thioredoxin reductase. Among a series of peroxides tested, linoleic acid hydroperoxide was the preferred substrate of BCP. By examining the profiles of protein expression within
H. pylori
cells, we confirmed that AhpC is much more abundant than BCP. The overlapping functions and activities of BCP and AhpC probably explain why the
bcp
mutant displayed a relatively weak oxidative stress resistance phenotype. The
bcp
mutant strain could colonize mouse stomachs, although colonization by the wild-type strain was slightly better than that by the mutant strain at 1 week after host inoculation. However, at 3 weeks after inoculation, the colonization ability of the wild type was significantly greater than that of the
bcp
mutant; for example,
H. pylori
was recovered from 10 of 11 mouse stomachs inoculated with the wild-type strain but from only 4 of 12 mice that were inoculated with the
bcp
mutant strain. This indicates that
H. pylori
BCP plays a significant role in efficient host colonization.
Chemokine Expression in the Monocytic Cell Line THP-1 in Response to Purified Shiga Toxin 1 and/or Lipopolysaccharides
Authors: Harrison Lisa M. , van den Hoogen Christel , van Haaften Wilhelmina C. E. , Tesh Vernon L. 
Published: December 2004

ABSTRACTInfections with Shiga toxin (Stx)-producing bacteria are associated with bloody diarrhea and postdiarrheal sequelae, including hemolytic uremic syndrome and central nervous system (CNS) abnormalities. Stx-induced intestinal, renal, and CNS vascular lesions may involve a localized production of proinflammatory cytokines in target organs, as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) up-regulate Stx receptor globotriaosylceramide (Gb3) expression on vascular endothelial cells. However, leukocyte recruitment to injured sites may also exacerbate vascular damage. A cytokine macroarray analysis of transcripts derived from macrophage-like THP-1 cells treated with Stx1, lipopolysaccharides (LPS), or both demonstrated a consistent up-regulation ofTNF-α,IL-1β, and four genes encoding the chemokines interleukin-8 (IL-8), macrophage inflammatory protein-1α (MIP-1α), MIP-1β, and growth-related oncogene beta (GRO-β). Real-time PCR analysis verified the macroarray results. Northern blot analyses after the addition of the transcriptional inhibitor actinomycin D revealed increased IL-8 mRNA stability in THP-1 cells treated with Stx1 or Stx1 plus LPS. Finally, enzyme-linked immunosorbent assay data for Stx1- plus LPS-treated cells demonstrated a poor correlation between IL-8, MIP-1α, MIP-1β, and GRO-β mRNA levels and protein production, indicating a posttranscriptional regulatory effect. Our data suggest that in response to Stx1 and LPS, macrophages may be a source of chemokines that promote tissue damage through leukocyte recruitment and activation.
Ehrlichia chaffeensisExpresses Macrophage- and Tick Cell-Specific 28-Kilodalton Outer Membrane Proteins
Authors: Singu Vijayakrishna , Liu Haijie , Cheng Chuanmin , Ganta Roman R. 
Published: December 2004

ABSTRACTEhrlichia chaffeensis, a tick-transmitted rickettsial agent, causes human monocyte/macrophage-tropic ehrlichiosis. In this study, proteomic approaches were used to demonstrate host cell-specific antigenic expression byE. chaffeensis. The differentially expressed antigens include those from the 28-kDa outer membrane protein (p28-Omp) multigene locus. The proteins expressed in infected macrophages are the products of p28-Omp19 and p28-Omp20 genes, whereas in tick cells, the protein expressed is the p28-Omp14 gene product. The differentially expressed proteins are posttranslationally modified by phosphorylation and glycosylation to generate multiple expressed forms. Host cell-specific protein expression is not influenced by growth temperatures and is reversible. Host cell-specific protein expression coupled with posttranslational modifications may be a hallmark for the pathogen's adaptation to a dual-host life cycle and its persistence.
A signalling role for muscle glycogen in the regulation of pace during prolonged exercise
Authors: Rauch H G L , St Clair Gibson A , Lambert E V , Noakes T D 
Published: December 2004

Introduction:In this study we examined the pacing strategy and the end muscle glycogen contents in eight cyclists, once when they were carbohydrate loaded and once when they were non-loaded.Methods:Cyclists completed 2 hours of cycling at ∼73% of maximum oxygen consumption, which included five sprints at 100% of peak sustained power output every 20 minutes, followed immediately by a 1 hour time trial. Muscle biopsies were performed before and immediately after exercise, while blood samples were taken during the 2 hour steady state rides and immediately after exercise.Results:Carbohydrate loading improved mean power output during the 1 hour time trial (mean (SEM) 219 (17)v233 (15) W; p<0.05) and enabled subjects to use significantly more muscle glycogen than during the trial following their normal diet. Significantly, the subjects, kept blind to all feedback except for time, started both time trials at similar workloads (∼30 W), but after 1 minute of cycling, the workload average 14 W higher throughout the loaded compared with the non-loaded time trial. There were no differences in subjects’ plasma glucose and lactate concentrations and heart rates in the carbohydrate loaded versus the non-loaded trial. Of the eight subjects, seven improved their time trial performance after carbohydrate loading. Finishing muscle glycogen concentrations in these seven subjects were remarkably similar in both trials (18 (3)v20 (3) mmol/kg w/w), despite significantly different starting values and time trial performances (36.55 (1.47)v38.14 (1.27) km/h; p<0.05). The intra-subject coefficient of variation (CV) for end glycogen content in these seven subjects was 10%, compared with an inter-subject CV of 43%.Conclusions:As seven subjects completed the time trials with the same end exercise muscle glycogen concentrations, diet induced changes in pacing strategies during the time trials in these subjects may have resulted from integrated feedback from the periphery, perhaps from glycogen content in exercising muscles.
Satellite Cell‐Derived Exosomes: A Novel Approach to Alleviate Skeletal Muscle Atrophy and Fibrosis
Authors: Liu Hongwen , Yuan Shiguo , Liu Gaofeng , Li Junhua , Zheng Kai , Zhang Zhiwei , Zheng Sheng , Yin Li , Li Yikai 
Published: February 2024

AbstractSkeletal muscle atrophy coincides with extensive fibrous tissue hyperplasia in muscle‐atrophied patients, and fibrous tissue plays a vital role in skeletal muscle function and hinders muscle fiber regeneration. However, effective drugs to manage skeletal muscle atrophy and fibrosis remain elusive. This study isolated and characterized exosomes derived from skeletal muscle satellite cells (MuSC‐Exo). The study investigated their effects on denervated skeletal muscle atrophy and fibrosis in Sprague Dawley (SD) rats via intramuscular injection. MuSC‐Exo demonstrated the potential to alleviate skeletal muscle atrophy and fibrosis. The underlying mechanism using single‐cell RNA sequencing data and functional analysis are analyzed. Mechanistic studies reveal close associations between fibroblasts and myoblasts, with the transforming growth factor β1 (TGF‐β1)‐Smad3‐Pax7 axis governing fibroblast activation in atrophic skeletal muscle. MuSC‐Exo intervention inhibited the TGF‐β1/Smad3 pathway and improved muscle atrophy and fibrosis. In conclusion, MuSC‐Exo‐based therapy may represent a novel strategy to alleviate skeletal muscle atrophy and reduce excessive fibrotic tissue by targeting Pax7 through the TGF‐β1/Smad3 pathway.
Wide‐Bandgap Polymers with a C(sp3)─F Polyfluoride Backbone Enable High‐Efficient Ternary Organic Solar Cells
Authors: He Zhilong , Zhang Yi , Lin Yi , Li Siyuan , Zhang Shimin , Xue Zhongyuan , Hao Zhe , Tang Zheng , Zhong Hongliang 
Published: February 2024

AbstractFluorination strategy is demonstrated to be a successful approach for optimizing the electron distribution and morphology of organic photovoltaic materials. The previous works focus on introducing only a few C(sp2)─F bonds into conjugated backbone or C(sp3)─F bonds into sidechains. Herein, a new strategy by introducing C(sp3)─F polyfluoride unit into the backbone is proposed, wherein the fluorine atoms are not involved into the conjugation but can promote the intermolecular interaction between backbones. Two wide‐bandgap fluoropolymers are prepared and employed as the third component for ternary organic solar cells. As expected, even if there are six fluorine atoms in a single repeat unit, the relevant fluoropolymers possess complementary absorption and aligned energy levels. More importantly, the polyfluoride backbone affords adequate non‐covalent interactions, consequently enhancing the polymer aggregation and packing order, which is verified by a fibril‐like morphology in the blend film with the host polymer PM6 and only 10 wt.% fluoropolymer. In addition, the decreased surface energy caused by polyfluoride unit is beneficial for the improvement of domain purity and the formation of nanoscale phase separation between donor and acceptor materials. As a result, the fluoropolymer‐assisted ternary device displays a higher efficiency of 18.74% compared with the binary device (17.39%).
Optimizing Color Saturation in Colloidal Photonic Crystals by Control of Absorber Amount and Distribution
Authors: Bittner Carina , Bleyer Gudrun , Nees Nico , Carneiro Miguel , Pflug Lukas , Stingl Michael , Vogel Nicolas 
Published: February 2024

AbstractNanostructured materials that mimic structural coloration in nature can be synthetically created by colloidal self‐assembly. To maximize optical effects, the natural world integrates melanin as a broadband absorber to remove incoherently scattered light. Polydopamine (PDA) is used as a synthetic analog of natural melanin to systematically investigate the influence of absorber quantity and distribution on color saturation in colloidal photonic crystals. The absorbing PDA is integrated into two distinct ways: homogenous colloidal crystals are produced from core–shell particles with incrementally increasing polydopamine shells, and heterogeneous colloidal crystals are formed by co‐assembly of varying ratios of polystyrene (PS) and absorbing PS@PDA particles. The chromaticity is quantified by converting the measured spectra to reconstructed colors in the L*a*b* color sphere to identify structures with optimal color saturation. Simulations based on the discrete dipole approximation (DDA) indicate that a homogeneous absorber distribution is most efficient in creating saturated structural coloration. Experiments, however, demonstrate that the heterogeneous absorber incorporation outperforms the homogeneous strategies, as it allows for a more precise adjustment of the absorber content in the required concentration range. These results underline the importance of incorporating absorbers and indicate efficient ways in which colloidal photonic crystals with saturated structural colors can be prepared.
An Intelligent Driving Monitoring System Utilizing Pedal Motion Sensor Integrated with Triboelectric‐Electromagnetic Hybrid Generator and Machine Learning
Authors: Lu Xiaohui , Leng Baichuan , Li Hengyu , Lv Xinzhan , Zhang Xiaosong , Qu Ting , Li Shaosong , Wang Yingting , Wen Jianming , Zhang Bangcheng , Cheng Tinghai 
Published: February 2024

AbstractDriver's driving behavior and driving style have a crucial impact on traffic safety, capacity, and efficiency, so it is of great significance to monitor the driver's driving behavior and recognize their driving style. In this work, an intelligent driving monitoring system based on a triboelectric nanogenerator and electromagnetic generator is designed. The system consists of a self‐powered pedal motion sensor (SPMS) and an intelligent data processing unit (IDPU), which can monitor driving behavior and recognize driving style. SPMS is used for driving behavior monitoring, which mainly consists of a six‐phase triboelectric nanogenerator (S‐TENG) and a free‐rotating disk electromagnetic generator (FD‐EMG). S‐TENG can recognize information such as pedal movement direction, movement amplitude, and movement speed, and FD‐EMG can realize the function of a self‐powered driver's driving behavior warning. The IDPU includes a numerical calculation system for driving style characteristic variables and a driving style classifier. It can recognize the driving style based on the driving data collected by SPMS. The driving style classifier design is based on a combination of simulated driving experiments and machine learning techniques, and its accuracy is verified through experiments. This work has important potential applications in the field of traffic safety and intelligent driving.
Rhodium(III)‐Catalyzed C7‐Spiroannulation of Indolines with Maleimides: Facile Access to Aza‐Spiromulticycles
Authors: Zhao Jinfang , Pi Chao , Wu Yangjie , Cui Xiuling 
Published: February 2024

AbstractHerein, we report a chemo‐ and regioselective Rh‐catalyzed redox C7‐spiroannulation reaction of N‐benzo[d]imidazole indolines with maleimides, resulting in a series of N‐benzo[d]imidazole indoline fused azaspirocycles in up to 92% yield. The synthetic utility is demonstrated by the synthesis of highly functionalized nitrogen‐containing spiropolycyclic skeletons. The annulation reaction could also be performed with maleic esters and acrylates. The products were purified by simple filtration. The Rh catalyst can be recycled, and the reaction could be performed at gram‐scale using 0.5 mol% of catalyst, which makes this protocol potentially applicable in industry. Moreover, the efficient post‐modification of pharmaceutical molecules demonstrates its practicability.
Cold Atmospheric Plasma: An Emerging Immunomodulatory Therapy
Authors: Liu Hui , Liang Xiaoliu , Teng Minglei , Li Zhenjie , Peng Yisheng , Wang Peiyu , Chen Hu , Cheng Hongwei , Liu Gang 
Published: February 2024

AbstractCold atmospheric plasma (CAP) is a novel technology that generates a unique combination of reactive oxygen and nitrogen species (ROS/RNS), electric fields, and UV radiation. CAP has shown promise in regulating the immune system and has potential clinical applications in wound healing, cancer treatment, and infection control. This review provides an overview of the immunological regulation activity of CAP, highlighting its substantial impact on cytokines production, immune cell phagocytosis, and immune cell proliferation. CAP has also been demonstrated to have potent therapeutic effect in anti‐inflammation, wound repair, viral and bacterial infections. Furthermore, CAP has been investigated as an adjuvant therapy for tumor treatment, eliciting a robust antitumor immune response and remarkable synergistic effects in diverse combination therapies. Further research is needed to fully understand the mechanisms underlying the effects of CAP on the immune system and to optimize its clinical application.
Live Organoid Cyclic Imaging
Authors: Reynolds David E. , Sun Yusha , Wang Xin , Vallapureddy Phoebe , Lim Jianhua , Pan Menghan , Fernandez Del Castillo Andres , Carlson Jonathan C. T. , Sellmyer Mark A. , Nasrallah MacLean , Binder Zev , O'Rourke Donald M. , Ming Guo‐li , Song Hongjun , Ko Jina 
Published: February 2024

AbstractOrganoids are becoming increasingly relevant in biology and medicine for their physiological complexity and accuracy in modeling human disease. To fully assess their biological profile while preserving their spatial information, spatiotemporal imaging tools are warranted. While previously developed imaging techniques, such as four‐dimensional (4D) live imaging and light‐sheet imaging have yielded important clinical insights, these technologies lack the combination of cyclic and multiplexed analysis. To address these challenges, bioorthogonal click chemistry is applied to display the first demonstration of multiplexed cyclic imaging of live and fixed patient‐derived glioblastoma tumor organoids. This technology exploits bioorthogonal click chemistry to quench fluorescent signals from the surface and intracellular of labeled cells across multiple cycles, allowing for more accurate and efficient molecular profiling of their complex phenotypes. Herein, the versatility of this technology is demonstrated for the screening of glioblastoma markers in patient‐derived human glioblastoma organoids while conserving their viability. It is anticipated that the findings and applications of this work can be broadly translated into investigating physiological developments in other organoid systems.
Benzylic C(sp3)−H Alkoxylation through Visible‐Light‐Driven Oxidative Radical‐Polar Crossover
Authors: Yamashita Kenji , Kawahara Fumiya , Hamashima Yoshitaka 
Published: February 2024

AbstractWe report a metal‐free method for benzylic C(sp3)−H alkoxylation with a silyl ether as an alkoxylating agent. The reaction is considered to proceed through a sequence consisting of hydrogen atom transfer (HAT) and oxidative radical‐polar crossover, wherein Selectfluor serves as a one‐electron oxidant, a HAT agent, and a fluoride ion source. The fluoride ion formed in situ activates the silyl ether to give the alkoxide nucleophile, which reacts with a benzyl cation intermediate to provide the benzyl ether product. The present protocol has a broad substrate scope, enabling C−H alkoxylation of primary, secondary, and tertiary benzylic C(sp3)−H bonds. Furthermore, it is applicable for late‐stage C−H alkoxylation of bioactive molecules.
Incremental value of amyloid PET in a tertiary memory clinic setting in China
Authors: Chen Ke‐Liang , Wang Ming‐Yu , Wu Jie , Zuo Chuan‐Tao , Huang Yu‐Yuan , Wang Wei‐Yi , Zhao Meng , Zhang Ya‐Ru , Zhang Xue , Chen Shu‐Fen , Liu Wei‐Shi , Li Meng‐Meng , Ge Jing‐Jie , Ma Xiao‐Xi , Wang Jie , Zheng Li , Guan Yi‐Hui , Dong Qiang , Cui Mei , Xie Fang , Zhao Qian‐Hua , Yu Jin‐Tai 
Published: February 2024

AbstractINTRODUCTIONThe objective of this study is to investigate the incremental value of amyloid positron emission tomography (Aβ‐PET) in a tertiary memory clinic setting in China.METHODSA total of 1073 patients were offered Aβ‐PET using 18F‐florbetapir. The neurologists determined a suspected etiology (Alzheimer's disease [AD] or non‐AD) with a percentage estimate of their confidence and medication prescription both before and after receiving the Aβ‐PET results.RESULTSAfter disclosure of the Aβ‐PET results, etiological diagnoses changed in 19.3% of patients, and diagnostic confidence increased from 69.3% to 85.6%. Amyloid PET results led to a change of treatment plan in 36.5% of patients. Compared to the late‐onset group, the early‐onset group had a more frequent change in diagnoses and a higher increase in diagnostic confidence.DISCUSSIONAβ‐PET has significant impacts on the changes of diagnoses and management in Chinese population. Early‐onset cases are more likely to benefit from Aβ‐PET than late‐onset cases.Highlights
Amyloid PET contributes to diagnostic changes and its confidence in Chinese patients.
Amyloid PET leads to a change of treatment plans in Chinese patients.
Early‐onset cases are more likely to benefit from amyloid PET than late‐onset cases.
Characterization and Engineering of Two Highly Paralogous Sesquiterpene Synthases Reveal a Regioselective Reprotonation Switch
Authors: Ye Dan , Shao Yi‐Zhen , Li Wen‐Rui , Cui Zhen‐Jia , Gong Ting , Yang Jin‐Ling , Wang Hai‐Qiang , Dai Jun‐Gui , Feng Ke‐Ping , Ma Ming , Ma Shuang‐Gang , Liu Yun‐Bao , Zhu Ping , Yu Shi‐Shan 
Published: February 2024

AbstractSesquiterpene synthases (STPSs) catalyze carbocation‐driven cyclization reactions that can generate structurally diverse hydrocarbons. The deprotonation‐reprotonation process is widely used in STPSs to promote structural diversity, largely attributable to the distinct regio/stereoselective reprotonations. However, the molecular basis for reprotonation regioselectivity remains largely understudied. Herein, we analyzed two highly paralogous STPSs, Artabotrys hexapetalus (−)‐cyperene synthase (AhCS) and ishwarane synthase (AhIS), which catalyze reactions that are distinct from the regioselective protonation of germacrene A (GA), resulting in distinct skeletons of 5/5/6 tricyclic (−)‐cyperene and 6/6/5/3 tetracyclic ishwarane, respectively. Isotopic labeling experiments demonstrated that these protonations occur at C3 and C6 of GA in AhCS and AhIS, respectively. The cryo‐electron microscopy‐derived AhCS complex structure provided the structural basis for identifying different key active site residues that may govern their functional disparity. The structure‐guided mutagenesis of these residues resulted in successful functional interconversion between AhCS and AhIS, thus targeting the three active site residues [L311‐S419‐C458]/[M311‐V419‐A458] that may act as a C3/C6 reprotonation switch for GA. These findings facilitate the rational design or directed evolution of STPSs with structurally diverse skeletons.