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A Numerical Characterization of the Gravito-Electrostatic Sheath Equilibrium Structure in Solar Plasma
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作者 Pralay Kumar Karmakar Chandra Bhushan Dwivedi 《International Journal of Astronomy and Astrophysics》 2011年第4期210-231,共22页
This article describes the equilibrium structure of the solar interior plasma (SIP) and solar wind plasma (SWP) in detail under the framework of the gravito-electrostatic sheath (GES) model. This model gives a precise... This article describes the equilibrium structure of the solar interior plasma (SIP) and solar wind plasma (SWP) in detail under the framework of the gravito-electrostatic sheath (GES) model. This model gives a precise definition of the solar surface boundary (SSB), surface origin mechanism of the subsonic SWP, and its supersonic acceleration. Equilibrium parameters like plasma potential, self-gravity, population density, flow, their gradients, and all the relevant inhomogeneity scale lengths are numerically calculated and analyzed as an initial value problem. Physical significance of the structure condition for the SSB is discussed. The plasma oscillation and Jeans time scales are also plotted and compared. In addition, different coupling parameters, and electric current profiles are also numerically studied. The current profiles exhibit an important behavior of directional reversibility, i.e., an electrodynamical transition from negative to positive value. It occurs beyond a few Jeans lengths away from the SSB. The virtual spherical surface lying at the current reversal point, where the net current becomes zero, has the property of a floating surface behavior of the real physical wall. Our investigation indicates that the SWP behaves as an ion current-carrying plasma system. The basic mechanism behind the GES formation and its distinctions from conventional plasma sheath are discussed. The electromagnetic properties of the Sun derived from our model with the most accurate available inputs are compared with those of others. These results are useful as an input element to study the properties of the linear and nonlinear dynamics of various solar plasma waves, oscillations and instabilities. 展开更多
关键词 SUN SOLAR Wind PLASMA gravito-electrostatic Coupling Processes INHOMOGENEITY Scale Lengths SOLAR Interior PLASMA gravito-electrostatic sheath SOLAR Models Electromagnetic SUN
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Effect of Sheath Modeling on Unbonded Post-Tensioned Concrete under Blast Loads
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作者 Hyeon-Sik Choi Min Kyu Kim +1 位作者 Jiuk Shin Thomas H.-K.Kang 《Computer Modeling in Engineering & Sciences》 2026年第1期399-415,共17页
Unbonded post-tensioned(PT)concrete systems are widely used in safety-critical structures,yet model-ing practices for prestress implementation and tendon-concrete interaction remain inconsistent.This study investigate... Unbonded post-tensioned(PT)concrete systems are widely used in safety-critical structures,yet model-ing practices for prestress implementation and tendon-concrete interaction remain inconsistent.This study investigates the effects of sheath(duct)implementation and confinement assumptions through nonlinear finite element analysis.Four modeling cases were defined,consisting of an explicit sheath without tendon-concrete confinement(S)and three no-sheath variants with different confinement levels(X,N,A).One-way beams and two-way panels were analyzed,and panel blast responses were validated against experimental results.In both beams and panels,average initial stress levels were similar across models,through local stress concentrations appeared when the sheath was modeled.Under blast loading,these local effects became critical,and the sheath-implemented model reproduced experimental behavior most accurately,whereas non-implemented models deviated.Reduced blast intensity diminished the differences among models,thereby reaffirming that sheath-induced localization and damage propagation are critical factors.These findings highlight the importance of explicit sheath implementation for realistic numerical assessment of unbonded PT structures under extreme loads. 展开更多
关键词 Unbonded post-tensioned concrete sheath implementation blast loading finite element analysis
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Crucial role of microglia-mediated myelin sheath damage in vascular dementia:Antecedents and consequences
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作者 Qi Shao Simin Chen +6 位作者 Yuxiao Zheng Wenxiu Xu Jiahui Chen Wei Shao Qingguo Wang Changxiang Li Xueqian Wang 《Neural Regeneration Research》 2026年第3期1000-1012,共13页
Chronic cerebral hypoperfusion can lead to neuronal necrosis,trigger inflammatory responses,promote white matter damage,and ultimately result in cognitive impairment.Consequently,chronic cerebral hypoperfusion is an i... Chronic cerebral hypoperfusion can lead to neuronal necrosis,trigger inflammatory responses,promote white matter damage,and ultimately result in cognitive impairment.Consequently,chronic cerebral hypoperfusion is an important factor influencing the onset and progression of vascular dementia.The myelin sheath is a critical component of white matter,and damage and repair of the white matter are closely linked to myelin sheath integrity.This article reviews the role of microglia in vascular dementia,focusing on their effects on myelin sheaths and the potential therapeutic implications.The findings suggest that ischemia and hypoxia cause disruption of the blood-brain barrier and activate microglia,which may worsen blood-brain barrier damage through the release of matrix-degrading enzymes.Microglia-mediated metabolic reprogramming is recognized as an important driver of inflammation.Damage to the blood-brain barrier and subsequent inflammation can lead to myelin injury and accelerate the progression of vascular dementia.Early activation of microglia is a protective response that contributes to the maintenance of blood-brain barrier integrity through sensing,debris-clearing,and defensive mechanisms.However,prolonged activation can trigger a shift in microglia toward the pro-inflammatory M1 phenotype,resulting in myelin damage and cognitive impairment.Triggering receptor expressed on myeloid cells 2 and triggering receptor expressed on myeloid cells 1 have been identified as potential biomarkers for vascular dementia,as both are closely linked to cognitive decline.Although effective clinical treatments for myelin damage in the central nervous system are currently lacking,researchers are actively working to develop targeted therapies.Several drugs,including nimodipine,dopaminergic agents,simvastatin,biotin,and quetiapine,have been evaluated for clinical use in treating microglial and myelin damage.Future research will face challenges in developing targeted therapeutic strategies for vascular dementia,requiring further investigation into the timing,duration,and specific mechanisms of microglial activation,as well as the exploration of new drug combinations and additional therapeutic targets. 展开更多
关键词 blood-brain barrier chronic cerebral hypoperfusion cognitive impairment MICROGLIA myelin sheath NEUROINFLAMMATION THERAPY TREM vascular dementia white matter
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OsERF7 Negatively Regulates Resistance to Sheath Blight Disease by Inhibiting Phytoalexin Biosynthesis 被引量:2
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作者 XIE Yuhao XIE Wenya +11 位作者 ZHAO Jianhua XUE Xiang CAO Wenlei SHI Xiaopin WANG Zhou WANG Yiwen WANG Guangda FENG Zhiming HU Keming CHEN Xijun CHEN Zongxiang ZUO Shimin 《Rice science》 2025年第3期367-379,I0059-I0065,共20页
Ethylene response factors(ERFs)are plant transcription agents that play a pivotal role in disease resistance through the ethylene signaling pathway.However,whether and how ERFs regulate resistance to sheath blight(ShB... Ethylene response factors(ERFs)are plant transcription agents that play a pivotal role in disease resistance through the ethylene signaling pathway.However,whether and how ERFs regulate resistance to sheath blight(ShB),caused by Rhizoctonia solani in rice,remains largely unknown.Here,we demonstrated that OsERF7 negatively regulates rice resistance to ShB by inhibiting phytoalexin biosynthesis.Overexpression of OsERF7(OsERF7OE)significantly decreased ShB resistance,whereas knockout of OsERF7(oserf7)enhanced it.Mechanistically,antioxidant enzyme activities are significantly reduced in OsERF7OE plants,but increased in oserf7 plants.Furthermore,transcriptome analysis revealed that oserf7 plants exhibited significant upregulation of pathogenesis-related(PR)and phytoalexin biosynthesis genes upon R.solani infection.Consistently,transcript levels of phytoalexin biosynthesis genes,including OsKSL7,OsKSL8,OsKOL5,and OsCPS4,were significantly elevated in oserf7 plants,but reduced in OsERF7OE plants in response to R.solani infection.Electrophoretic mobility shift assays and dual-luciferase(LUC)reporter assays further confirmed that OsERF7 directly binds to the promoters of OsKSL8,OsKOL5,and OsCPS4,thereby repressing their expression.In summary,our study revealed that OsERF7 negatively regulated rice resistance to ShB primarily by inhibiting phytoalexin biosynthesis. 展开更多
关键词 RICE sheath blight OsERF7 PHYTOALEXIN
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Cyt02 encodes cytochrome P450 monooxygenase,increasing rice(Oryza sativa L.)resistance to sheath blight 被引量:1
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作者 Tengda Zheng Xiaolin Wang +9 位作者 Yuewen He Deqiang Li Andrews Danso Ofori Xing Xiang Abdul Ghani Kandhro Xiaoqun Yi Fu Huang Jianqing Zhu Ping Li Aiping Zheng 《The Crop Journal》 2025年第1期92-103,共12页
Rice sheath blight(RSB)is a major destructive disease impeding rice production.Identifying key germplasm resources with increased resistance remains a challenge.However,the mechanisms underlying disease resistance are... Rice sheath blight(RSB)is a major destructive disease impeding rice production.Identifying key germplasm resources with increased resistance remains a challenge.However,the mechanisms underlying disease resistance are not yet fully understood.Cytochrome P450 monooxygenases(CYP450s)serve biosynthesis and metabolic detoxification functions in plants,but there is limited information about their role in the response induced by RSB.This study demonstrated that CYT02 belongs to the CYP73A100 subfamily and is a typical member of the CYP450s.Overexpression(OE)in rice of the cytochrome P450 monooxygenase cyt02 conferred increased resistance to RSB and increased vegetative tillering.Cyt02 may increase RSB resistance by regulating plant hormone synthesis,regulate reactive oxygen species(ROS)by coordinating the activity of antioxidant enzymes,and initiate phytoalexin synthesis in response to fungal infection.These research findings have laid a foundation for a deeper understanding of the function of cyt02 and offered a potential target gene for breeding rice varieties resistant to sheath blight. 展开更多
关键词 RICE sheath blight Cytochrome P450 monooxygenase Metabolomics analysis Functional analysis
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Enhancing postoperative pain control by surgically-initiated rectus sheath block in abdominal aortic aneurysm open repair: A case report
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作者 Kuan-Hua Chen Ming-Yuan Kang +2 位作者 Yi-Ting Chang Sheng-Yang Huang Yung-Szu Wu 《World Journal of Clinical Cases》 SCIE 2025年第6期41-47,共7页
BACKGROUND Abdominal aortic aneurysm(AAA)repair often involves significant postoperative pain,traditionally managed with systemic opioids,which can cause undesirable side effects.This case report explores the novel us... BACKGROUND Abdominal aortic aneurysm(AAA)repair often involves significant postoperative pain,traditionally managed with systemic opioids,which can cause undesirable side effects.This case report explores the novel use of a surgically-initiated rectus sheath block with a catheter-over-needle assembly for pain management in AAA repair.CASE SUMMARY A 67-year-old female with hypertension and previous aortic dissection underwent elective open repair of an infrarenal AAA,which had grown from 3.4 cm to 4.3 cm over 14 months.A rectus sheath block was initiated surgically for postoperative pain control.The patient reported low pain scores and did not require systemic intravenous opioids,enabling early ambulation and discharge on postoperative day seven without complications.By preventing complications of systemic opi-oids,the method indicating a promising direction for postoperative pain management in major vascular surgeries.CONCLUSION Surgically-initiated rectus sheath block as a valuable tool for managing postoperative pain in AAA repair. 展开更多
关键词 Abdominal aortic aneurysm Postoperative pain management Rectus sheath block Surgical anesthesia Opioid-sparing techniques Case report
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Sensitivity Determination of Rice Sheath Blight Pathogen to Shenqinmycin in Northeast China
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作者 Zhang Junhua Hou Lei +3 位作者 Wo Sanchao Niaz Nihal Ni Zhe Yang Mingxiu 《Journal of Northeast Agricultural University(English Edition)》 2025年第3期14-22,共9页
Rice sheath blight is one of the serious rice diseases causing economic losses worldwide.Shenqinmycin,a broad-spectrum microbial metabolite pesticide,inhibits plant pathogens.This study investigated the sensitivity of... Rice sheath blight is one of the serious rice diseases causing economic losses worldwide.Shenqinmycin,a broad-spectrum microbial metabolite pesticide,inhibits plant pathogens.This study investigated the sensitivity of rice sheath blight pathogen to the biological pesticide by treating 45 strains isolated from three northeastern provinces with varying concentrations of Shenqinmycin.The effects on mycelial growth and sclerotial germination of the rice sheath blight pathogens were measured to determine the resistance levels.The results indicated that all tested strains were sensitive to Shenqinmycin,with EC50 values for Rhizoctonia solani ranging from 0.0487 mg·L^(-1) to 0.2348 mg·L^(-1),and a sensitivity baseline of 0.1292 mg·L^(-1).For Rhizoctonias oryzae-sativae,the EC50 values ranged from 0.0517 mg·L^(-1) to 0.1697 mg·L^(-1),with a sensitivity baseline of 0.1163 mg·L^(-1).Shenqinmycin had no effect on the sclerotial germination of either pathogen,suggesting its potential as an effective agent for controlling rice sheath blight. 展开更多
关键词 SHENQINMYCIN rice sheath blight Rhizoctonia solani Rhizoctonias oryzae-sativae sensitivity
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Built-In Electric Field Effects Tailoring Solvation Sheath and Desolvation Processes of Solvated Zn^(2+)Toward Stable Aqueous Rocking-Chair Zinc-Ion Batteries
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作者 Peng Cai Xin He +7 位作者 Kangli Wang Zidong Zhang Qingyuan Wang Yumeng Liu Haomiao Li Min Zhou Wei Wang Kai Jiang 《Carbon Energy》 2025年第5期1-20,共20页
Currently,although some progress has been made in infancy-stage rocking-chair aqueous zinc-ion batteries(AZIBs),more discussions have focused only on the different electrochemical performances displayed by different m... Currently,although some progress has been made in infancy-stage rocking-chair aqueous zinc-ion batteries(AZIBs),more discussions have focused only on the different electrochemical performances displayed by different material types rather than the intrinsic ion transport migration electrochemistry.Herein,we for the first time delve into the mechanism of tailoring the solvation sheath and desolvation processes at the electrode/electrolyte interfaces to enhance the structural stabilities in the deep discharge states.In this work,the TiO_(2)front interfaces are induced on electrochemically active but unstable TiSe_(2)host materials to construct unique TiO_(2)/TiSe_(2)-C heterointerfaces.According to X-ray absorption near edge structure(XANES),differential electrochemical mass spectrometry(DEMS),and electrochemical quartz crystal microbalance(EQCM),the intercalated species are transformed from[Zn(H_(2)O)_(6)]^(2+)to[Zn(H_(2)O)_(2)]^(2+)due to the built-in electric fields(BEFs)effects,further accelerating the ion transfer kinetics.Furthermore,owing to the absence of high-energy desolvation solvents released from desolvation processes,hydrogen evolution reaction(HER)energy barriers,Ti-Se bond strength,and structural stabilities are significantly improved,and the initial CE and HER overpotentials of the TiO_(2)/TiSe_(2)-C heterointerfaces increased from 13.76%to 84.7%,and from 1.04 to 1.30 V,respectively,and the H2 precipitation current density even at-1.3 V decreased by 73.2%.This work provides valuable insights into the complex interface electrochemical mechanism of tailoring the solvation sheath and desolvation processes toward rocking-chair zinc-ion batteries. 展开更多
关键词 DESOLVATION heterointerfaces hydrogen evolution reaction rocking-chair zinc-ion batteries solvation sheath
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Point-of-care ultrasonography for detecting raised intracranial pressure through optic nerve sheath diameter in non-traumatic headache patients
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作者 Yehya Tlaiss Alaa Tarchichi +7 位作者 Katherine Atallah Ehab Al Mashtoub Issa Zalzali Zeinab Chokor Issam Fassih Najah Harb Jane Kassas Hussein Hamze 《World Journal of Radiology》 2025年第11期50-58,共9页
Non-traumatic headache is a common presentation in both emergency and outpatient settings,where timely identification of raised intracranial pressure(ICP)is crucial to prevent severe neurological complications.Convent... Non-traumatic headache is a common presentation in both emergency and outpatient settings,where timely identification of raised intracranial pressure(ICP)is crucial to prevent severe neurological complications.Conventional diagnostic methods such as computed tomography and lumbar puncture have important limitations,including invasiveness,delayed availability,and limited sensitivity in certain contexts.Point-of-care ultrasound measurement of the optic nerve sheath diameter(ONSD)has emerged as a rapid,non-invasive tool for detecting elevated ICP at the bedside.The technique is based on the anatomical continuity between the intracranial subarachnoid space and the optic nerve sheath,which expands in response to increased ICP.Evidence from multiple studies and meta-analyses indicates that ONSD measurements above 5.0-5.7 mm in adults strongly correlate with elevated ICP,showing pooled sensitivities and specificities approaching 90%.This modality enables immediate triage,guides urgency of neuroimaging,reduces unnecessary radiation exposure,and can be applied in outpatient and low-resource settings.Despite these advantages,ONSD assessment is subject to operator dependency,variability in threshold values,and reduced accuracy in patients with certain ocular or systemic conditions.Advances in artificial intelligence–assisted measurement,coupled with standardized training protocols,have the potential to improve reproducibility and broaden adoption.Overall,point-of-care ultrasound-based ONSD measurement represents a valuable adjunct in the early evaluation of patients with non-traumatic headache,facilitating faster diagnosis,better resource utilization,and improved patient outcomes. 展开更多
关键词 Point-of-care ultrasound Optic nerve sheath diameter Intracranial pressure HEADACHE NON-TRAUMATIC
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Control Fungicide Screening and Resistance Monitoring to Thifluzamide of Rice Sheath Blight Pathogen Rhizoctonia solani in Heilongjiang Province
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作者 Zhang Junhua Lv Anqi +6 位作者 Chen Wanying Liu Qingran Xiong Tianliang Zhang Yifei Tian Ziyu Wu Jiaju Zhao Guohui 《Journal of Northeast Agricultural University(English Edition)》 2025年第2期1-9,共9页
In recent years,the prevalence of rice sheath blight caused by Rhizoctonia solani has significantly increased in Heilongjiang Province.Chemical control has become the primary control method.To cope with this,a novel m... In recent years,the prevalence of rice sheath blight caused by Rhizoctonia solani has significantly increased in Heilongjiang Province.Chemical control has become the primary control method.To cope with this,a novel mycelium growth rate method was employed to assess the toxicity of 13 fungicides,including a combination of 45%prochloraz and 125 g·mL^(-1)epoxiconazole,against R.solani.Additionally,the resistance of 99 R.solani strains to thifluzamide across various regions was also evaluated.The findings indicated that 75%trifloxystrobin-tebuconazole exhibited the most effective inhibitory effect,with an effective inhibitory medium concentration(EC50)value of 0.0101μg·mL^(-1).The EC50 values for 20%prothioconazole,125 g·mL^(-1)epoxiconazole,24%thifluzamide,and 50%hexaconazole were all less than 10μg·mL^(-1),indicating a better inhibitory effect on R.solani.The strongest synergistic effect was noted in the mixture of prochloraz and epoxiconazole at a 1:2 ratio,resulting in an EC50 value of 2.9917μg·mL^(-1),and a co-toxicity coefficient of 213.38.Among the 34 strains from Harbin City,the average EC50 value was 196.9341μg·mL^(-1)indicating the highest susceptiblility to thifluzamide.Conversely,15 strains from Shuangyashan City exhibited an average EC50 value of 364.7323μg·mL^(-1),reflecting the lowest sensitivity to thifluzamide.The sensitivity baseline EC50 value for R.solani was 253.8854μg·mL^(-1),with an overall resistance level between 0.1567 and 3.3292,indicating that the resistance level of R.solani in Heilongjiang Province remained low.Therefore,R.solani was still sensitive to thifluzamide in most areas of Heilongjiang Province,but there was a certain risk of resistance in Qitaihe City,which needed to be continuously monitored.At the same time,this study might provide a theoretical foundation for enhancing the prevention and management of the rice sheath blight. 展开更多
关键词 rice sheath blight Rhizoctonia solani fungicide screening THIFLUZAMIDE resistance monitoring
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Tailoring solvation sheath and desolvation processes of weakly solvated Zn^(2+) through heterointerfaces built-in electric field effects for ultra-stable aqueous zinc batteries
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作者 Peng Cai Mengjun Li +7 位作者 Xin He Xianbo Zhou Zhenyu Lei Haomiao Li Min Zhou Wei Wang Kangli Wang Kai Jiang 《Advanced Powder Materials》 2025年第3期34-45,共12页
Solvated zinc ions are prone to undergo desolvation at the electrode/electrolyte interfaces,and unstable H_(2)O molecules within the solvated sheaths tend to trigger hydrogen evolution reaction(HER),further accelerati... Solvated zinc ions are prone to undergo desolvation at the electrode/electrolyte interfaces,and unstable H_(2)O molecules within the solvated sheaths tend to trigger hydrogen evolution reaction(HER),further accelerating interfaces decay.Herein,we propose for the first time a novel strategy to enhance the interfacial stabilities by insitu dynamic reconstruction of weakly solvated Zn2þduring the desolvation processes at heterointerfaces.Theoretical calculations indicate that,due to built-in electric field effects(BEFs),the plating/stripping mechanism shifts from[Zn(H_(2)O)_(6)]_(2)þto[Zn(H_(2)O)_(5)(SO_(4))^(2-)]_(2)þwithout additional electrolyte additives,reducing the solvation ability of H_(2)O,enhancing the competitive coordination of SO_(4)^(2-),essentially eliminating the undesirable side effects of anodes.Hence,symmetric cells can operate stably for 3000 h(51.7-times increase in cycle life),and the full cells can operate stably for 5000 cycles(51.5-times increase in cycle life).This study provides valuable insights into the critical design of weakly solvated Zn^(2+) þand desolvation processes at heterointerfaces. 展开更多
关键词 DESOLVATION Heterointerfaces Solvation sheath Built-in electric field effects Zinc metal anodes
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Optic nerve sheath diameter trajectories and mortality in children with clinically relevant elevated intracranial pressure
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作者 Dat Minh-Tan Truong Minh Hoang-Nhat Nguyen +2 位作者 Huy Quang Nguyen Luan Thanh Vo Thanh Tat Nguyen 《World Journal of Critical Care Medicine》 2025年第4期235-246,共12页
BACKGROUND The optic nerve sheath diameter(ONSD)measured by ultrasound has emerged as a significant noninvasive method for detecting elevated intracranial pressure(ICP),guiding timely interventions,and monitoring trea... BACKGROUND The optic nerve sheath diameter(ONSD)measured by ultrasound has emerged as a significant noninvasive method for detecting elevated intracranial pressure(ICP),guiding timely interventions,and monitoring treatment response.Previous studies have shown that the baseline ONSD at admission is a prognostic indicator of mortality in adult patients with cerebrovascular events,traumatic brain injury,hepatic encephalopathy,and acute stroke.However,pediatric data on the dynamic changes in ONSD remain limited.AIM To study the association between within-48 hours admission dynamic ONSD changes and mortality in children with clinically relevant elevated ICP.METHODS This single-institution prospective study was performed at a tertiary Children’s Hospital in Vietnam,between November 2023 and August 2024.The primary outcome was in-hospital mortality rate.ONSD data were measured at admission,24 hours,and 48 hours post-admission to pediatric intensive care unit(PICU).Linear mixed-effects models accounting for repeated measures within individuals were used to analyze the association between ONSD changes and in-hospital mortality.RESULTS A total of 69 PICU-admitted children with clinically relevant raised ICP were enrolled and included in the analysis.The median patient age was 6 years(interquartile range:1-12),and males accounted for 54%of all patients.The inhospital mortality rate in children with clinically relevant raised ICP was 23.2%.Traumatic brain injury,sepsisassociated encephalopathy,and septic shock were the main causes of death in this cohort.Linear mixed-effects analysis showed that dynamic variability in ONSD values upon PICU admission and during the first 48 hours later correlated significantly with increased mortality.Nonsurvivors had a 5.3%increase in the mean ONSD at 48 hours compared to baseline levels,while the survivors showed a 5.6%reduction in ONSD.CONCLUSION Serial ultrasound-based ONSD measurements within 48 hours of admission better predicted mortality than baseline data in critically ill children,offering a practical,noninvasive tool for early prognosis in elevated ICP. 展开更多
关键词 Glasgow coma scale Intracranial pressure MORTALITY Optic nerve sheath diameter Pediatric intensive care unit
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膨胀型防火涂料在电缆材料中的应用及作用机制分析
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作者 颜渊巍 牛振 +4 位作者 娄建坤 秦伟 唐沛杰 赵海波 郭德明 《化学研究与应用》 北大核心 2026年第2期308-317,共10页
随着我国电力系统向高电压、大容量、智能化方向迭代升级,防火耐火电线电缆材料的高性能化迫在眉睫。无卤膨胀型防火阻燃涂料能显著提升材料的防火安全性能,在防火耐火电线电缆领域具有重要应用价值。本研究通过用乙醇胺(ETA)与聚磷酸铵... 随着我国电力系统向高电压、大容量、智能化方向迭代升级,防火耐火电线电缆材料的高性能化迫在眉睫。无卤膨胀型防火阻燃涂料能显著提升材料的防火安全性能,在防火耐火电线电缆领域具有重要应用价值。本研究通过用乙醇胺(ETA)与聚磷酸铵(APP)通过离子交换反应制备得到阻燃剂ETA-APP,进而与APP和季戊四醇(PER)构成阻燃复配体系,加入到环氧树脂涂料中制备得到无卤膨胀型防火阻燃涂料。系统研究了该涂料在国标RW护套线/电缆皮的应用效果及作用机制,结果表明,涂料涂覆后的样品在极限氧指数(LOI)、垂直燃烧(UL-94)、锥形量热等多项火安全测试中均表现出了阻燃防火性能的明显提升,样品最高LOI达30.6%,通过UL-94 V-0等级,峰值热释放速率、总热释放和六分钟的总烟释放量大幅降低;扫描电镜、单根绝缘电线电缆火焰垂直蔓延试验、红外热成像分析表明,涂料很可能是在燃烧过程中通过自身的分解,在高温下参与了凝聚相杂化炭层的形成,从而能阻止聚合物基线缆进一步热解、防止其内部的热分解产生物进入气相参与燃烧过程。本研究为电气领域,特别是电线电缆的高效阻燃防火提供了新的设计策略与理论支持。 展开更多
关键词 护套线 电缆皮 防火 涂料
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基于护套电流的高压电缆金属护套接地系统故障诊断判据综述
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作者 赵洋 马宪伟 +3 位作者 程养春 黄子健 周戈 郭甜 《高压电器》 北大核心 2026年第4期17-28,共12页
高压电缆金属护套接地系统对电缆安全运行至关重要,同时故障占比较高。金属护套接地电流的监测结果能够反映电缆金属护套接地系统健康状态,是评价高压电缆线路运行状态的重要依据。解释了金属护套环流的形成机理,介绍了金属护套接地系... 高压电缆金属护套接地系统对电缆安全运行至关重要,同时故障占比较高。金属护套接地电流的监测结果能够反映电缆金属护套接地系统健康状态,是评价高压电缆线路运行状态的重要依据。解释了金属护套环流的形成机理,介绍了金属护套接地系统的常见缺陷,对国内外应用金属护套电流诊断金属护套接地系统缺陷的判据进行了全面梳理,并通过现场案例比较了现行判据的效果,为进一步提出更准确和全面的诊断判据提供参考。 展开更多
关键词 高压电缆 护套电流 故障诊断 综述
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无固相一步式冲洗液对钻井液滤饼的清洗机理与性能
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作者 张福铭 赵琥 +3 位作者 张高雷 赵军 王雪山 程小伟 《钻井液与完井液》 北大核心 2026年第1期80-88,共9页
随着环保法规的日益严格,环保型水基钻井液在海洋钻井中得到广泛应用,其形成的致密滤饼会严重影响固井二界面胶结质量。以BIODRILL水基钻井液滤饼为研究对象,结合XRD、FT-IR、SEM、TG等手段揭示了其成分和结构特征,发现滤饼主要由高分... 随着环保法规的日益严格,环保型水基钻井液在海洋钻井中得到广泛应用,其形成的致密滤饼会严重影响固井二界面胶结质量。以BIODRILL水基钻井液滤饼为研究对象,结合XRD、FT-IR、SEM、TG等手段揭示了其成分和结构特征,发现滤饼主要由高分子聚合物、加重材料和黏土矿物构成,滤饼孔隙度低、强度高,常规方法难以清除。基于滤饼形成机理,设计了一种由草酸、NaF、EDTA-Na、鼠李糖脂和TWEEN80组成的无固相一步式冲洗液。该体系通过“酸解–螯合–界面剥离–物理冲刷”的协同机制,实现了滤饼的高效溶解与剥离。实验结果表明,在pH值为5.5下,冲洗液在室温和85℃下均可在15 min内达到80%以上的滤饼去除率;冲洗后岩心胶结强度可恢复至空白岩心的70%以上,满足现场对冲洗液性能的要求。研究结果不仅揭示了钻井液滤饼的清洗难点和形成机制,还为复杂环境下固井二界面滤饼的高效清除与胶结质量的提升提供了新思路和理论依据。 展开更多
关键词 钻井液 滤饼 固井二界面 冲洗液 清洗机理
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危重患者心腔内电图联合超声引导下3种PICC置管方式比较研究
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作者 赵志莹 陈国连 +7 位作者 陈莹莹 刘伟宸 张小芳 黄钰清 韦洁静 叶将霞 麻玲霞 甘洁梅 《护理学杂志》 北大核心 2026年第3期53-57,共5页
目的比较心腔内电图联合超声引导下3种PICC置管方式在危重患者中的有效性与安全性,为PICC置管临床操作提供参考。方法将2023年12月至2024年8月行PICC置管的188例危重患者按置管时间分成三组,分别采用改良送鞘PICC置管术(改良送鞘组)63例... 目的比较心腔内电图联合超声引导下3种PICC置管方式在危重患者中的有效性与安全性,为PICC置管临床操作提供参考。方法将2023年12月至2024年8月行PICC置管的188例危重患者按置管时间分成三组,分别采用改良送鞘PICC置管术(改良送鞘组)63例,一针式隧道PICC置管术(一针隧道组)60例,两针式隧道PICC置管术(两针隧道组)65例;三组均在心腔内电图和超声的引导下置管。观察三组患者置管的有效性(一次穿刺成功率、一次置管成功率、置管时间)和安全性(穿刺及维护过程中各种并发症发生率)。结果三组一次穿刺成功率、一次置管成功率和置管时间比较,差异有统计学意义(均P<0.05),其中改良送鞘组和两针隧道组一次穿刺成功率、一次置管成功率显著高于一针隧道组,改良送鞘组置管时间显著短于一针隧道组和两针隧道组(均P<0.017);三组渗血发生率、脱管率比较,差异有统计学意义(均P<0.05),其中两针隧道组渗血发生率显著高于改良送鞘组和一针隧道组,改良送鞘组脱管率显著高于一针隧道组和两针隧道组(均P<0.017)。结论改良送鞘PICC置管术效率高、渗血少,但脱管风险高;一针式隧道PICC置管术脱管率低,但一次穿刺和置管成功率低,置管时间长;两针式隧道PICC置管术一次穿刺和置管成功率高,但渗血率高,操作更复杂。临床应根据患者的具体情况个体化地选择最优置管方式。 展开更多
关键词 危重患者 PICC 置管术 心腔内电图定位技术 改良送鞘法 隧道式送鞘 渗血 脱管 静脉治疗护理
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肾结石患者掺铥激光联合头部可弯曲负压鞘治疗后尿路感染的影响因素 被引量:1
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作者 王超 岳大顺 +4 位作者 曲直 邢劲 张立文 李晨曦 杨立军 《中华保健医学杂志》 2026年第1期82-86,共5页
目的 探究肾结石患者接受掺铥激光联合头部可弯曲负压鞘治疗后发生尿路感染的影响因素。方法回顾性分析2023年1月~2025年1月期间北京友谊医院平谷医院收治的198例肾结石患者的临床资料,并根据是否发生尿路感染,将患者分为感染组(n=25)... 目的 探究肾结石患者接受掺铥激光联合头部可弯曲负压鞘治疗后发生尿路感染的影响因素。方法回顾性分析2023年1月~2025年1月期间北京友谊医院平谷医院收治的198例肾结石患者的临床资料,并根据是否发生尿路感染,将患者分为感染组(n=25)和未感染组(n=173)。收集患者的临床资料,比较感染组与未感染组之间各临床资料的差异,并通过logistic多元回归模型分析术后尿路感染的主要影响因素。结果感染组的手术时间(76.24±21.43)min、住院时间(9.88±2.99)d比未感染组手术时间(68.03±18.51)min、住院时间(8.11±2.06)d更长,差异有统计学意义(t=2.031、3.769,P=0.044、0.000)。两组患者在术前尿路感染、合并糖尿病、预防性应用抗菌药物、结石残留、双J管留置时间、尿路感染史、肾积水程度、抗菌药物使用种类、结石直径、白细胞(WBC)计数、血清白蛋白(ALB)比较,差异有统计学意义(χ^(2)=5.239、26.062、4.074、3.968、5.639、30.495、12.991、6.967、4.138、6.924、11.411,P<0.05)。logistic多元回归模型分析显示,合并糖尿病(OR=1.582,95%CI:1.366~1.798,P=0.041)、预防性应用抗菌药物<2(OR=0.495,95%CI:0.278~0.712,P=0.019)、双J管留置时间(OR=1.637,95%CI:1.291~1.983,P=0.025)、结石残留(P=0.018,OR=2.108,95%CI:1.832~3.384)以及抗菌药物使用种类(OR=1.879,95%CI:1.628~2.130,P=0.036)是术后尿路感染的主要影响因素。结论肾结石患者接受掺铥激光联合头部可弯曲负压鞘治疗后,合并糖尿病、结石残留、预防性应用抗菌药物<2、双J管留置时间过长以及使用多种抗菌药物是术后尿路感染的主要危险因素,故应及时采取相应的预防策略以降低术后尿路感染的发生率,改善患者预后。 展开更多
关键词 肾结石 掺铥激光 头部可弯曲负压鞘 术后尿路感染
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井冈霉素配施纳米硅肥对水稻光合特性、防御酶活性和纹枯病防控效果的影响
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作者 郭锦全 周友军 《中国稻米》 北大核心 2026年第1期64-69,75,共7页
发展病害绿色防控技术有利于水稻产业健康可持续发展。为明确井冈霉素与纳米硅肥配施对水稻纹枯病的防控效果及对水稻光合特性、防御酶活性的影响,以野香优669为参试品种开展试验,旨在筛选出最优的配施方案。结果表明,与CK(喷施等量无菌... 发展病害绿色防控技术有利于水稻产业健康可持续发展。为明确井冈霉素与纳米硅肥配施对水稻纹枯病的防控效果及对水稻光合特性、防御酶活性的影响,以野香优669为参试品种开展试验,旨在筛选出最优的配施方案。结果表明,与CK(喷施等量无菌水)相比,井冈霉素配施纳米硅肥能够显著提升水稻的光合特性。其中,喷施5%井冈霉素A可湿性粉剂125 g+纳米硅肥700 mL处理的表现最好。该处理下,水稻总叶绿素含量达到4.69 mg/g,净光合速率(Pn)为14.90μmol/(m^(2)·s),气孔导度(Gs)为0.47μmol/(m^(2)·s),细胞间隙CO_(2)浓度(Ci)为268.70μmol/mol,蒸腾速率(Tr)为5.30 mmol/(m^(2)·s);潜在光化学效率(Fv/Fo)、PSII最大光化学效率(Fv/Fm)、光化学淬灭系数(qP)和非光化学淬灭系数(NPQ)等叶绿素荧光参数均显著高于其他处理;超氧化物歧化酶(SOD)、过氧化物酶(POD)、多酚氧化酶(PPO)及苯丙氨酸解氨酶(PAL)等抗氧化防御酶活性在该处理中均最高,分别为513.3、875.1、117.7和47.9 U/(g·h)。同时,采用该处理方式的水稻病情指数为2.18,防效达76.20%,对水稻纹枯病的防控效果在各处理中最佳。综上所述,喷施5%井冈霉素A可湿性粉剂125 g+纳米硅肥700 mL的处理能够改善水稻的叶绿素含量、光合特性及叶绿素荧光参数,激发抗氧化防御酶活性,对水稻纹枯病具有良好的防控效果。 展开更多
关键词 水稻 井冈霉素 纳米硅肥 光合特性 纹枯病
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基于有效积温的玉米叶片和叶鞘干物质动态积累模型及特征参数分析
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作者 张伟彬 刘沛义 +4 位作者 许海涛 郭海斌 王月 王素奇 张军刚 《南方农业学报》 北大核心 2026年第1期91-103,共13页
【目的】探索基于有效积温的玉米叶片和叶鞘干物质动态积累模型并分析其特征参数,为选育高效利用光热资源的玉米品种及挖掘品种产量潜力提供理论依据。【方法】以玉米品种驻玉216、裕丰303、中科玉505和郑单958为试验材料开展春、夏播... 【目的】探索基于有效积温的玉米叶片和叶鞘干物质动态积累模型并分析其特征参数,为选育高效利用光热资源的玉米品种及挖掘品种产量潜力提供理论依据。【方法】以玉米品种驻玉216、裕丰303、中科玉505和郑单958为试验材料开展春、夏播田间试验,采用Logistic方程基于有效积温构建不同玉米品种叶片、叶鞘干物质动态积累模型,利用田间实测值对模型进行检验,并分析其模型特征参数。【结果】春、夏播玉米叶片和叶鞘干物质量与有效积温均呈极显著正相关(P<0.01),叶片和叶鞘干物质量均历经渐增期—快增期—缓增期3个过程,随有效积温呈S形变化趋势,且不同玉米品种间叶片和叶鞘干物质积累规律基本一致。基于有效积温构建的玉米叶片和叶鞘干物质增长Logistic模型具有实际生物学意义,决定系数R2分别为0.9799~0.9922、0.9781~0.9963,标准化均方根误差nRMSE分别为10.38%~23.71%、12.71%~28.80%,实测值均匀分布于模拟曲线两侧,且极接近于模拟曲线,达到良好预测水平。玉米叶片和叶鞘干物质进入快增期所需有效积温分别为479.21~576.75℃·d、550.39~665.42℃·d,达最大生长速率所需有效积温分别为579.74~731.68℃·d、647.94~810.14℃·d,快增期平均生长速率分别为0.0680~0.1276 g/(℃·d)和0.0404~0.0706 g/(℃·d)。【结论】基于有效积温构建的Logistic模型对玉米叶片和叶鞘的干物质积累动态变化具有较好的预测性与解释性,可用于不同玉米品种叶片和叶鞘干物质积累的动态估测,具有较强的应用价值。 展开更多
关键词 玉米 有效积温 叶片干物质 叶鞘干物质 LOGISTIC模型
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超声测量视神经鞘直径评估颅内压的研究进展
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作者 张静 孙建(综述) 刘晓琴(审校) 《检验医学与临床》 2026年第2期283-288,共6页
颅内压(ICP)升高往往提示预后不良甚至导致死亡。超声测量视神经鞘直径(ONSD)作为一种无创评估ICP的方法,具有价格低廉、安全可靠、操作简单等优点,在临床上具有广泛的应用潜力。该文从超声测量ONSD评估ICP升高的机制、操作方法、临床... 颅内压(ICP)升高往往提示预后不良甚至导致死亡。超声测量视神经鞘直径(ONSD)作为一种无创评估ICP的方法,具有价格低廉、安全可靠、操作简单等优点,在临床上具有广泛的应用潜力。该文从超声测量ONSD评估ICP升高的机制、操作方法、临床应用及进展等角度出发,探讨了其在不同地区(如高海拔地区)及不同民族中的应用情况,表明ONSD与ICP升高存在显著线性相关性,且具有较高的灵敏度和特异度,但在高海拔地区,ONSD受低氧等因素影响,其正常值范围可能高于海平面地区,且存在民族差异,需综合考虑多种因素以提高诊断准确度。目前,超声测量ONSD在评估ICP升高方面虽有诸多优点,但仍存在一些不足,如在特殊环境下的正常值范围界定不够精准等。未来需进一步探索超声测量ONSD与其他检测手段的联合应用,以提高诊断准确度和可靠性,推动其在临床中的广泛应用。 展开更多
关键词 颅内压 超声 视神经鞘直径 眼球横径 高海拔地区 预后
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