检索结果-南通市图书馆

Reduction of epinephrine in the lumbar spinal cord following repetitive blast-induced traumatic brain injury in rats

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第7期19卷 1548-1552页

作者： Shigeharu Tsuda Mustafa Golam Jiamei Hou kevin k.w.wang Floyd J.Thompson Prodip Bose Brain Rehabilitation Research Center Malcom Randall VA Medical CenterNorth Florida/South Georgia Veterans Health SystemGainesvilleFLUSA Department of Anesthesiology College of MedicineUniversity of FloridaGainesvilleFLUSA Department of Emergency Medicine University of FloridaGainesvilleFLUSA Department of Neuroscience University of FloridaGainesvilleFLUSA Department of Neurology University of FloridaGainesvilleFLUSA

Traumatic brain inju ry-induced unfavorable outcomes in human patients have independently been associated with dysregulated levels of monoamines,especially epinephrine,although few preclinical studies have examined the epinephrine level in the central nervous system after traumatic brain *** has been shown to regulate the activities of spinal motoneurons as well as increase the heart rate,blood pressure,and blood flow to the hindlimb ***,the purpose of the present study was to determine the impact of repeated blast-induced traumatic brain injury on the epinephrine levels in seve ral function-s pecific central nervous system regions in *** three repeated blast injuries at 3-day intervals,the hippocampus,motor cortex,locus coeruleus,vestibular nuclei,and lumbar spinal cord were harvested at post-injury day eight and processed for epinephrine assays using a high-sensitive electrochemical detector cou pled with high-performance liquid *** results showed that the epinephrine levels were significantly decreased in the lumbar spinal cord tissues of blast-induced traumatic brain injury animals compared to the levels detected in age-and sex-matched sham *** other function-specific central nervous system regions,although the epinephrine levels were slightly altered following blast-induced tra u matic brain injury,they were not statistically *** results suggest that blast injury-induced significant downregulation of epinephrine in the lumbar spinal cord could negatively impact the motor and cardiovascular *** is the first repo rt to show altered epinephrine levels in the spinal cord following repetitive mild blast-induced traumatic brain injury.

关键词： balance blood flow cardiovascular system central nervous system epinephrine ischemic damage lumbar spinal cord muscle tone repeated blast spasticity traumatic brain injury

Elevated brain temperature under severe heat exposure impairs cortical motor activity and executive function

在线全文

学校读者我要写书评

暂无评论

Journal of Sport and Health Science 2024年第2期13卷 233-244页

作者： Xiang Ren Tan Mary C.Stephenson Sharifah Badriyah Alhadad kelvin w.Z.Loh Tuck.w.h Soong Jason k.w.Lee Ivan C.C.Low Health and Social Sciences Singapore Institute of TechnologySingapore 138683Singapore Human Potential Translational Research Programme Yong Loo Lin School of MedicineNational University of SingaporeSingapore 117597Singapore Centre for Translational Magnetic Resonance Research Yong Loo Lin School of MedicineNational University of SingaporeSingapore 117549Singapore Department of Physiology Yong Loo Lin School of MedicineNational University of SingaporeSingapore 117593Singapore Heat Resilience and Performance Centre Yong Loo Lin School of MedicineNational University of SingaporeSingapore 117510Singapore N.1 Institute for Health National University of SingaporeSingapore 117456Singapore Campus for Research Excellence and Technological Enterprise(CREATE) Singapore 138602Singapore

Background:Excessive heat exposure can lead to hyperthermia in humans,which impairs physical performance and disrupts cognitive *** heat is a known physiological stressor,it is unclear how severe heat stress affects brain physiology and ***:Eleven healthy participants were subjected to heat stress from prolonged exercise or warm water immersion until their rectal temperatures(T_(re))attained 39.5℃,inducing exertional or passive hyperthermia,*** a separate trial,blended ice was ingested before and during exercise as a cooling *** were compared to a control condition with seated rest(normothermic).Brain temperature(T_(br)),cerebral perfusion,and task-based brain activity were assessed using magnetic resonance imaging ***:T_(br)in motor cortex was found to be tightly regulated at rest(37.3℃±0.4℃(mean±SD))despite fluctuations in T_(re).with the development of hyperthermia,T_(br)increases and dovetails with the rising T_(re).Bilateral motor cortical activity was suppressed during high-intensity plantarflexion tasks,implying a reduced central motor drive in hyperthermic participants(T_(re)=38.5℃±0.1℃).Global gray matter perfusion and regional perfusion in sensorimotor cortex were reduced with passive *** function was poorer under a passive hyperthermic state,and this could relate to compromised visual processing as indicated by the reduced activation of left lateral-occipital ***,ingestion of blended ice before and during exercise alleviated the rise in both T_(re)and T_(bc)and mitigated heat-related neural ***:Severe heat exposure elevates T_(br),disrupts motor cortical activity and executive function,and this can lead to impairment of physical and cognitive performance.

关键词： Brain functional activity Cognition Heat stress Hyperthermia Motor function

Aqueous-phase reforming of hydroxyacetone solution to bio-based H_(2)over supported Pt catalysts

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2024年第4期9卷 777-788页

作者： A.k.k.Vikla k.koichumanova Songbo He k.Seshan Joint International Research Laboratory of Circular Carbon Nanjing Tech UniversityNanjing211816China Faculty of Science and Technology University of Twente7500 AE EnschedeThe Netherlands CoRe Pro 9723 BL GroningenThe Netherlands

Aqueous-phase reforming(APR)is an attractive process to produce bio-based hydrogen from waste biomass streams,during which the catalyst stability is often challenged due to the harsh reaction *** this work,three Pt-based catalysts supported on C,AlO(OH),and ZrO_(2)were investigated for the APR of hydroxyacetone solution in afixed bed reactor at 225℃and 35 *** them,the Pt/C catalyst showed the highest turnover frequency for H_(2)production(TOF of 8.9 molH_(2)molPt^(-1)min^(-1))and the longest catalyst *** the AlO(OH)and ZrO_(2)supported Pt catalysts,the side reactions consuming H_(2),formation of coke,and Pt sintering result in a low H_(2)production and the fast catalyst *** proposed reaction pathways suggest that a promising APR catalyst should reform all oxygenates in the aqueous phase,minimize the hydrogenation of the oxygenates,maximize the wGS reaction,and inhibit the condensation and coking reactions for maximizing the hydrogen yield and a stable catalytic performance.

关键词： APR Hydroxyacetone TOF Bio-based H_(2) Support effect

Tumor necrosis factor-alpha, transforming growth factor-beta, degree of lower urinary tract symptoms as predictors of erectile dysfunction in benign prostatic hyperplasia patients

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Urology 2024年第2期11卷 280-285页

作者： Gede w.k.Duarsa Yeremia G.kusumah Ronald Sugianto Pande M.w.Tirtayasa Tjokorda G.B.Mahadewa Department of Urology Faculty of MedicineUniversitas UdayanaProf.Dr.I.G.N.G Ngoerah General HospitalBaliIndonesia Department of General Surgery Faculty of MedicineUniversitas UdayanaProf.Dr.I.G.N.G Ngoerah General HospitalBaliIndonesia Medical Doctor Study Program Faculty of MedicineUniversitas UdayanaBaliIndonesia Department of Urology Faculty of MedicineUniversitas UdayanaUniversitas Udayana Teaching HospitalBaliIndonesia Department of Neurosurgery Faculty of MedicineUniversitas UdayanaProf.Dr.I.G.N.G Ngoerah General HospitalBaliIndonesia

Objective: Erectile dysfunction (ED) is a condition of insufficient penile erection, consistently or recurrently, for sexual activity. Tumor necrosis factor-alpha (TNF-α) induces transforming growth factor-beta (TGF-β), which causes the transition of epithelial cells into mesenchymal cells that affect ED. This study aimed to evaluate the roles of TNF-α, TGF-β, degree of lower urinary tract symptoms, and prostatic volume for the presence of ED in benign prostatic hyperplasia (BPH) ***: Our study performed an analytic observational retrospective cohort study using secondary data from four hospitals in Bali, Indonesia, including medical records and other administrative data. The sample was BPH patients with several history ***: Our sample was 83 respondents, ranging from 50 years to 80 years, 61 respondents with ED and 22 with non-ED. The International Prostate Symptom Score showed a significant result, which indicates that ED is more common in patients with higher International Prostate Symptom Score (p=0.002). Moreover, the TNF-α of ≥43.9 pg/mg and TGF-β of ≥175.8 pg/mL were significantly associated with the presence of ED in BPH patients (pwith ED (p=0.947).Conclusion: TNF-α, TGF-β, and lower urinary tract symptoms severity can predict the occurrence of ED in BPH, while prostatic volume was not significant.

关键词： Prostate enlargement Biomarker Erectiledysfunction Riskfactor

应用带有k空间加权图像对比(kwIC)重组技术的径向梯度回波序列行自由呼吸下胸腹部动态对比增强MRI

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

国际医学放射学杂志 2013年第4期 393-394页

作者： k.w. kim J.M. Lee Y.S. Jeon S.E. kang J.H. Baek J.k. Han 苏亚文 Department of Radiology and Institute of Radiation Medicine Seoul National University College of Medicine28 Yeongon-dongJongno-gu Seoul 110-744 Korea

目的评估应用带有k-空间加权图像对比(kwIC)重建技术的径向梯度回波序列行自由呼吸下胸腹部动态对比增强(DCE)MRI的可行性。方法本研究经机构审查委员会批准。14例病人行自由呼吸下径向DCE-MRI。径向MRI通过填充所有k空间数据获取全帧影... 详细信息

目的评估应用带有k-空间加权图像对比(kwIC)重建技术的径向梯度回波序列行自由呼吸下胸腹部动态对比增强(DCE)MRI的可行性。方法本研究经机构审查委员会批准。14例病人行自由呼吸下径向DCE-MRI。径向MRI通过填充所有k空间数据获取全帧影像,应用kwIC重建技术获取具有时间分辨率的子帧影像。应用子帧kwIC影像,创建逐体素灌注图。作为对比,在平衡期同时行屏气下常规Cartesian 3D梯度回波序列(VIBE)扫描。定量和定性地比较径向影像和常规VIBE影像的影像质量。结果径向DCE-MRI影像具有高的空间分辨率(1.4mm×1.4mm)和时间分辨率(每个子帧影像为4.1s),并可创建逐体素灌注图,仅伴有很少的运动或线样伪影。全帧的径向影像和常规VIBE影像的SNR之间无显著差异(79.08与74.80,P>0.05)。全帧径向影像的整体影像质量评分略低于常规的VIBE影像(3.88±0.59与4.31±0.97,Pk空间加权像对比(kwIC)重组技术的径向MRI具有潜在的可提升空间。③径向DCE-MRI可保持良好的影像质量,减少伪影并具有高的空间/时间分辨率。

关键词：动态对比增强MRI 径向MRI 自由呼吸 k空间灌注

Superexchange and charge transfer in the nickelate superconductor La_(3)Ni_(2)O_(7) under pressure

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第11期67卷 1-8页

作者： wéi wú Zhihui Luo Dao-Xin Yao Meng wang Center for Neutron Science and Technology Guangdong Provincial Key Laboratory of Magnetoelectric Physics and DevicesSchool of PhysicsSun Yat-sen UniversityGuangzhou 510275China

Recently, a bulk nickelate superconductor La_(3)Ni_(2)O_(7) is discovered at pressures with a remarkable high transition temperature T_(c)~ 80 k. Here, we study a Hubbard model with tight-binding parameters derived from ab initio calculations of La_(3)Ni_(2)O_(7),by employing large scale determinant quantum Monte Carlo and cellular dynamical mean-field theory. Our result suggests that the superexchange couplings in this system are comparable to that of cuprates. The system is a charge transfer insulator as the hole concentration becomes four per site at large Hubbard U. Upon hole doping, two low-energy spin-singlet bands emerge in the system exhibiting distinct correlation properties: while the one composed of the out-of-plane Ni-d_(3z^(2)-r^(2)) and O-p_(z) orbitals demonstrates strong antiferromagnetic correlations and narrow effective bandwidth, the in-plane singlet band consisting of the Ni-d_(x^(2)-y^(2)) and O-p_(x)/p_(y) orbitals is in general more itinerant. Over a broad range of hole doping, the doped holes occupy primarily the d_(x^(2)-y^(2)) and p_(x)/p_(y) orbitals, whereas the d_(3z^(2)-r^(2)) and p_(z) orbitals retain underdoped. we propose an effective t-J model to capture the relevant physics and discuss the implications of our result for comprehending the La_(3)Ni_(2)O_(7) superconductivity.

关键词： superconductivity nickelate superconductors Hubbard model superexchange charge transfer insulator quantum Monte Carlo

在线全文

学校读者我要写书评

暂无评论

麦克玛斯特大学“问题学习法”

复旦教育论坛 2003年第3期1卷 85-88页

作者：李泽生冼利青麦克玛斯特大学中山大学广州510080

本文从麦克玛斯特大学“问题学习法”(problem basedlearning)实施过程的各个方面 :教育目标、教学安排、教学活动、教学评价、教学资源等方面介绍了PBL的教学过程 ,总结了麦克玛斯特大学PBL课程设置以学生为本 ,培养学生的学习态度和... 详细信息

本文从麦克玛斯特大学“问题学习法”(problem basedlearning)实施过程的各个方面 :教育目标、教学安排、教学活动、教学评价、教学资源等方面介绍了PBL的教学过程 ,总结了麦克玛斯特大学PBL课程设置以学生为本 ,培养学生的学习态度和终身学习的能力以及在教学过程中倡导以生物心理社会医学模式培养适合社会发展需要的医生的经验。

关键词：麦克玛斯特大学 “问题学习法” 教学安排教学评价教学资源加拿大

Nickel sulfate solution fluoride separation with hydrous zirconium oxide

在线全文

学校读者我要写书评

暂无评论

Tungsten 2024年第2期6卷 367-381页

作者： Elbert M.Nigri Ummul k.Sultana André L.A.Santos James w.Vaughan Sonia D.F.Rocha Department of Mining Engineering Federal University of Minas GeraisBelo Horizonte 31270-901Brazil School of Chemical Engineering University of QueenslandSt Lucia 4072Australia

Fluoride is an impurity in nickel sulfate production,which is required for electric vehicle *** zirconium oxide(HZO)was evaluated for removing fl uoride from nickel sulfate *** fluoride removal occurred at pH value 4 and optimal pH value is 4–5,considering Zr *** availability decreases with pH due to hydrogen fluoride and zirconium fluoride aqueous *** removal is initially rapid,with 50 wt.%removal in 7 min,followed by slow removal up to 68 wt.%after 72 h and follows second order rate *** removal was dominated by an ion exchange mechanism and resulting Zr–F bonds were observed using Fourier-transform infrared *** presence of nickel sulfate decreased loading capacity compared to a salt-free *** maintained adsorption capacity through five cycles of loading and regeneration.

关键词： Hydrous zirconium oxide Nickel sulfate Fluoride Adsorption Anion exchange

Superplasticity of fine-grained Mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第1期12卷 316-331页

作者： H.T.Jeong S.w.Lee w.J.kim Department of Materials Science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

The superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the HCPαphase,were examined in a temperature range of 473 k to 623 *** microstructural refinement of this alloy was achieved by employing high-ratio differential speed *** best superplasticity was achieved at 523 k and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were *** the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 ***,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and *** the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation *** was concluded that solute drag creep is unlikely to *** the late stages of deformation at 523 k,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain *** mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： Magnesium-lithium alloy Superplasticity Severe plastic deformation Grain size Grain growth