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超短激光脉冲作用下生物组织体光学响应的时域和频域分析──Dirichlet边界条件和无向点激励源 被引量:4
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作者 高峰 牛憨笨 张焕文 《光子学报》 EI CAS CSCD 1997年第10期865-876,共12页
生物组织体在超短激光脉冲激励下的表面光学响应特性,如光子平均飞行路径、光通量、相移和调制深度等,在光学时域及频域无损测量、组织体光谱学和光学三维成象研究中具有重要的意义,而生物组织体对近红外和可见光呈现的高散射特性使... 生物组织体在超短激光脉冲激励下的表面光学响应特性,如光子平均飞行路径、光通量、相移和调制深度等,在光学时域及频域无损测量、组织体光谱学和光学三维成象研究中具有重要的意义,而生物组织体对近红外和可见光呈现的高散射特性使得激励光子在组织体内的传输行为复杂化,精确地测定和计算上述光学响应量一直是人们感兴趣的问题.本文基于描述组织体内光子传输的扩散方程模型,阐述了时域、频域测量的等效性,从无限空间几何结构出发,逐次导出了常见几何形状均匀组织体光学响应的解析表示,在此基础上给出了典型参数下的计算结果并讨论了计算中可能出现的问题及其解决方法. 展开更多
关键词 生物组织体 超短激光脉冲 无损测量 光学响应
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血流灌注延时对活体生物组织温度动力学特性影响的研究
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作者 冯秀舟 《中国血液流变学杂志》 CAS 2001年第4期265-266,共2页
目的 探讨血流灌注率随温度改变的延迟时间τ对加热活体生物组织时温度变化形式的影响。方法 用根轨迹法对活体生物组织不同的延时τ进行跟踪观察。结果 不同的延时τ能产生不同的温度振荡形式。
关键词 血流灌注延时 根轨迹 生物组织 温度振荡形式
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离体生物组织相变潜热的DSC测试 被引量:2
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作者 胡银平 童明伟 +1 位作者 严嘉 徐广才 《重庆大学学报(自然科学版)》 EI CAS CSCD 北大核心 2006年第11期62-65,共4页
差示扫描量热法是一种在线性温度程序控制下经过温度扫描,以所测能量差来研究物质热力学性质的热分析方法.文中分别对部分离体生物组织如猪瘦肉、猪肝、猪肥肉及牛肉的相变温度、相变潜热进行了DSC测试,获得了相变潜热及相变温度区间.... 差示扫描量热法是一种在线性温度程序控制下经过温度扫描,以所测能量差来研究物质热力学性质的热分析方法.文中分别对部分离体生物组织如猪瘦肉、猪肝、猪肥肉及牛肉的相变温度、相变潜热进行了DSC测试,获得了相变潜热及相变温度区间.结果表明组织水分含量越高、脂肪含量越低,其相变潜热较大. 展开更多
关键词 生物组织 相变潜热 相变温度 差示扫描量热法
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在体生物组织导热系数和血流率的测量
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作者 何杰 陈超敏 《华南理工大学学报(自然科学版)》 EI CAS CSCD 1994年第A12期139-144,共6页
关键词 生物组织 导热系数 血流率 生物组织
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直角坐标系中第二类边界条件下一维生物组织温度场的稳态分析解及实验研究 被引量:6
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作者 王补宣 王艳民 蔡伟明 《工程热物理学报》 CSCD 北大核心 1995年第1期65-69,共5页
本文概述了生物传热方程分析求解的概况,利用多孔体模型的生物传热方程求得了直角坐标系中、第二类边界条件和常物性条件下的一维稳态分析解,模拟研究了不同无因次参数对在体生物组织温度场的影响,并对生物组织温度场进行了实验检验... 本文概述了生物传热方程分析求解的概况,利用多孔体模型的生物传热方程求得了直角坐标系中、第二类边界条件和常物性条件下的一维稳态分析解,模拟研究了不同无因次参数对在体生物组织温度场的影响,并对生物组织温度场进行了实验检验性的研究。 展开更多
关键词 生物组织 温度场 分析解 试验
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生物组织阻抗温度特性测试系统的研究 被引量:3
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作者 张琴艳 武文斌 马艺馨 《电子设计工程》 2014年第20期135-138,共4页
肿瘤热疗过程中的温度检测和控制是热疗的关键,但温度的无损检测方法较为缺乏,限制了其发展。文中研究了一种装置测试生物组织电阻抗的温度特性,为基于电阻抗特性的温度无损检测技术提供依据。该装置利用恒温水循环原理对组织进行加热,... 肿瘤热疗过程中的温度检测和控制是热疗的关键,但温度的无损检测方法较为缺乏,限制了其发展。文中研究了一种装置测试生物组织电阻抗的温度特性,为基于电阻抗特性的温度无损检测技术提供依据。该装置利用恒温水循环原理对组织进行加热,可使组织受热均匀并且温度易于控制,阻抗测量装置采用四电极法原理,可有效消除接触阻抗和极化效应的影响,提高测量精度。文中还研究设计了用于激励的恒流源发生电路,恒流源的输出阻抗在频率为1 MHz时为212 kΩ,具有很好的恒流特性。基于此系统,对两组新鲜肥肉组织进行了测试,研究了其电阻抗温度特性及频率特性,测试结果表明,离体肥肉组织电阻抗实部随频率升高而降低,虚部先降低后升高,转折频率在80~120k Hz之间;其温度特性表现为:小于53℃时,组织电阻抗随着温度升高呈现较为缓慢下降的趋势,在53~59℃之间,电阻抗以及电阻抗变化系数形成一个突变,表现出组织电阻抗变化的临界特性,这为进一步进行肿瘤热疗过程中基于电阻抗技术的温度无损监控提供了理论和实验依据。 展开更多
关键词 生物组织 生物电阻抗 肿瘤热疗 温度监控 四电极法
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激光生物学应用
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《中国光学》 EI CAS 1998年第5期31-31,共1页
Q631 98053009双层生物组织模拟体中光分布的实验研究=Experi-mental study of light distribution in two—lay—er phantoms[刊,中]/林煜(华侨大学材料物理化学研究所。福建,泉州(362011))∥激光杂志。—1997,18(6)。—49—51拟建立... Q631 98053009双层生物组织模拟体中光分布的实验研究=Experi-mental study of light distribution in two—lay—er phantoms[刊,中]/林煜(华侨大学材料物理化学研究所。福建,泉州(362011))∥激光杂志。—1997,18(6)。—49—51拟建立一套实验装置,测量双层生物组织模拟体中的光分布,并将实验结果与理论计算的结果进行了比较。图4参11(严兰) 展开更多
关键词 双层生物组织模拟 光分布 激光 实验研究 缺血性卒中 实验装置 材料物理 理论计算 华侨大学 化学研究所
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生物活体组织温度振荡行为的动力稳定性分析 被引量:3
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作者 刘静 任泽霈 王存诚 《科学通报》 EI CAS CSCD 北大核心 1996年第2期167-169,共3页
生物组织受热扰动而发生温度变动的情形可视为一个动力学过程.作者提出的生物活体组织温升振荡效应的热波理论,并述及两种求取振荡准则的方法,但头一种方法所获准则系物性的隐含形式,不便于定量分析物性参数的影响规律;后一种方法虽能... 生物组织受热扰动而发生温度变动的情形可视为一个动力学过程.作者提出的生物活体组织温升振荡效应的热波理论,并述及两种求取振荡准则的方法,但头一种方法所获准则系物性的隐含形式,不便于定量分析物性参数的影响规律;后一种方法虽能说明问题,但却略显粗糙.为此,本文采用Liapnov稳定性分析方法重新就此进行讨论,得到了更宽意义上的振荡准则和基于该现象的更深刻的认识.本文还定义了一个新的具有鲜明物理意义的无量纲参数W_t.一维直角坐标下生物体的波动传热方程为(见文献[1])中(4)式,其中为简单计,K, W_b, 展开更多
关键词 温度振荡 动力稳定性 生物组织 生物组织
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Endocare型氩氦冷刀冻结与复温性能的实验研究 被引量:21
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作者 于天骅 王洪武 +3 位作者 周一欣 刘静 冯华松 陆海英 《航天医学与医学工程》 CAS CSCD 北大核心 2003年第1期60-62,共3页
目的对Endocare型氩氦冷刀的实际工作性能进行测试 ,考察其优缺点 ,为肿瘤冷冻治疗提供参考。方法将氩氦刀置于空气、水及兔子组织中进行冷冻并复温 ,监测刀杆外壁和内部测温点的温度变化 ;基于实验结果评价氩氦刀的工作性能以及工质气... 目的对Endocare型氩氦冷刀的实际工作性能进行测试 ,考察其优缺点 ,为肿瘤冷冻治疗提供参考。方法将氩氦刀置于空气、水及兔子组织中进行冷冻并复温 ,监测刀杆外壁和内部测温点的温度变化 ;基于实验结果评价氩氦刀的工作性能以及工质气体的消耗情况 ;结果氩氦刀冷冻时 ,刀头在很短的时间内降至极低温度 ,并保持稳定。冰球在冷冻初期增长很快 ,此后其增长速率明显下降。当工质由氩切换为氦后 ,刀头温度迅速上升 ,冰球随即熔化 ;工质气体的消耗速率随着实验进行不断降低。结论证实氩氦刀确有良好的快速冷冻和复温性能 。 展开更多
关键词 实验研究 冷冻刀 生物组织 冻结 复温 消耗速率 冷冻外科
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Directional solidification and characterization of NiAl-9Mo eutectic alloy 被引量:1
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作者 张建飞 沈军 +2 位作者 商昭 王雷 傅恒志 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第12期3499-3507,共9页
Ni-45.5Al-9Mo (mole fraction,%) alloy was directionally solidified with a constant temperature gradient (GL=334 K/cm) and growth rates ranging from 2 to 300 μm/s using a Bridgman type crystal growing facility wit... Ni-45.5Al-9Mo (mole fraction,%) alloy was directionally solidified with a constant temperature gradient (GL=334 K/cm) and growth rates ranging from 2 to 300 μm/s using a Bridgman type crystal growing facility with liquid metal cooling (LMC) technique. The effect of growth rate (v) on the solidified microstructures such as rod spacing (λ), rod size (d) and rod volume fraction was experimentally investigated. Two types of the solidified interfaces, planar and cellular, were identified. On the condition of both planar and cellular eutectic microstructures, the relationships between λ, d and v were given as: λv1/2=5.90 μm·μm1/2·s1/2 and dv1/2=2.18μm·μm1/2·s1/2, respectively. It was observed that the volume fraction of Mo phase could be adjusted in a certain range. The variation of phase volume fraction was attributed to undercooling increase and the growth characteristics of the individual constituent phases during the eutectic growth. 展开更多
关键词 NiAl-9Mo directional solidification INTERMETALLICS crystal growth MICROSTRUCTURE
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Effect of thermal stabilization on microstructure and mechanical property of directionally solidified Ti-46Al-0.5W-0.5Si alloy 被引量:1
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作者 樊江磊 李新中 +3 位作者 苏彦庆 陈瑞润 郭景杰 傅恒志 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第5期1073-1080,共8页
Effect of thermal stabilization on the microstructure and mechanical property of directionally solidified Ti-46Al-0.5W-0.5Si (mole fraction, %) alloy was investigated. The specimens were thermal stabilized for diffe... Effect of thermal stabilization on the microstructure and mechanical property of directionally solidified Ti-46Al-0.5W-0.5Si (mole fraction, %) alloy was investigated. The specimens were thermal stabilized for different time (t) and directionally solidified at a constant growth rate of 30 μm/s and temperature gradient of 20 K/mm. Dependencies of the primary dendritic spacing (λ1), secondary dendritic spacing (λ2), interlamellar spacing (λL) and microhardness (HV) on holding time were determined. The values of the λ1, λ2 and λL increase with the increase of t, and the value of HV decreases with the increase of t. The increase of t is helpful to obtain a good directional solidification structure. However, it reduces the mechanical property of the directionally solidified TiAl alloy. The optimized value of t is about 30 min. 展开更多
关键词 INTERMETALLICS TiAl-based alloy crystal growth microstructure evolution mechanical properties
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Influences of Carbon Sources and Plant Growth Regulators on Anther Culture Efficiency of Pepper 被引量:9
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作者 赵激 邹学校 +2 位作者 张竹青 杨博智 周书栋 《Agricultural Science & Technology》 CAS 2010年第4期102-105,共4页
[Objective]In order to increase anther culture efficiency of pepper.[Method]MS culture media and Bolajiaohong were used in this experiment to study the influences of carbon sources and concentrations on anther callus ... [Objective]In order to increase anther culture efficiency of pepper.[Method]MS culture media and Bolajiaohong were used in this experiment to study the influences of carbon sources and concentrations on anther callus induction of pepper.Jiayu was taken as a material to study influences of plant growth regulators and concentrations on anther callus induction of pepper according to L16(4^5) orthogonal design.[Result]The average callus and embryoid induction rates of maltose at all concentrations were higher than these of sucrose but the difference was not significant.Taking maltose or sucrose as a carbon source,3% to 6% concentration was good for increasing induction frequencies of calli and embryoids.However,If the concentration was over 6%,the induction rates were declined dramatically with the increase of sugar concentration.The influences of growth regulators on induction rate of calli were listed as 2,4-D﹥ZT﹥NAA﹥KT﹥6-BA;the influences on induction rates of embryoids were listed as 2,4-D﹥NAA﹥ZT﹥KT﹥6-BA.The 2,4-D,ZT,NAA and KT had signficant or extremely significant influences on induction rates of calli and embryoids.2,4-D,ZT at 1.0 mg/L and NNA,KT at 0.5 mg/L had the best effects.The influences of ZT on calli and embryoids were better than those of KT and 6-BA.1.0 mg/L 2,4-D +1.0 mg/L ZT +0.5 mg/L KT +0.5 mg/L 6-BA was the best regulator combination for induction culture of Jiayu anther.[Conclusion]The experiment provided research basis for anther culture of pepper. 展开更多
关键词 PEPPER Anther culture Carbon source Plant growth regulator CALLUS EMBRYOID
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论无丝分裂 被引量:2
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作者 沈浩然 《菏泽师专学报》 2001年第2期94-95,共2页
论述了无丝分裂的方式,发生无丝分裂的生物体组织,无丝分裂过程中遗传物质的变化,无丝分裂在细胞增殖中的作用及生物学意义.
关键词 无丝分裂 妨锤丝 遗传物质 细胞分裂 生物组织体 细胞增殖
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Non invasive fibrosis biomarkers reduce but not substitute the need for liver biopsy 被引量:33
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作者 Giada Sebastiani Alfredo Alberti 《World Journal of Gastroenterology》 SCIE CAS CSCD 2006年第23期3682-3694,共13页
Chronic liver diseases are very common worldwide, particularly those linked to viral hepatitis and to alcoholic and non-alcoholic fatty liver. Their natural history is variable and long-term evolution differs in indiv... Chronic liver diseases are very common worldwide, particularly those linked to viral hepatitis and to alcoholic and non-alcoholic fatty liver. Their natural history is variable and long-term evolution differs in individual patients. Optimised clinical management of compensated chronic liver diseases requires precise definition of the stage of liver fibrosis, the main determinant of prognosis and of most therapeutic decisions. Liver biopsy is the gold standard for assessment of hepatic fibrosis. However, it is invasive with possible complications, costly and prone to sampling errors. Many non-invasive markers of liver fibrosis have been recently proposed and assessed in the clinical setting as surrogates of liver biopsy. Direct markers are based on biochemical parameters directly linked to fibrogenesis while indirect markers use simple or more sophisticated parameters that correlate with liver fibrosis stages. Non-invasive markers of liver fibrosis have been tested in different forms of chronic liver disease and showed variable diagnostic performance, but accuracy rarely was above 75%-80%. Better results were obtained when markers were combined. On this line, we have recently proposed a set of algorithms that combine sequentially indirect non-invasive markers of liver fibrosis, reaching 90%-95% diagnostic accuracy with significant reduction in the need for liver biopsy. Based on available evidence, it can be anticipated that non-invasive markers of liver fibrosis and their combined use will soon become a most useful tool in the clinical management of many forms of chronic liver disease. However, their implementation is expected to reduce, but not to completely eliminate, the need for liver biopsy. 展开更多
关键词 Chronic liver diseases Hepatic fibrosis Liverbiopsy Non invasive fibrosis markers
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Leptin: a multifunctional hormone 被引量:35
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作者 HUANG Lu, CAI LI(Tel: (214)-648-3340 Fax: (214)-648-9191 E-mail: li03@utsw.swmed.edu)(1 Touchstone Center for Diabetes Research1 Departments of Physiology and,2 Departments of Internal MedicineThe University of Texas Southwestern Medical Center5323 H. 《Cell Research》 SCIE CAS CSCD 2000年第2期81-92,共12页
Leptin is the protein product encoded by the obese (ob)gene. It is a circulating hormone produced primarily by the adipose tissue. ob/ob mice with mutations of the gene encoding leptin become morbidly obese, infertile... Leptin is the protein product encoded by the obese (ob)gene. It is a circulating hormone produced primarily by the adipose tissue. ob/ob mice with mutations of the gene encoding leptin become morbidly obese, infertile, hyperphagic, hypothermic,and diabetic. Since the cloning of leptin in 1994, our knowledge in body weight regulation and the role played by leptin has increased substantially. We now know that leptin signals through its receptor, OB-R, which is a member of the cytokine receptor superfamily. Leptin serves as an adiposity signal to inform the brain the adipose tissue mass in a negative feedback loop regulating food intake and energy expenditure. Leptin also plays important roles in angiogenesis, immune function, fertility and bone formation. Humans with mutations in the gene encoding leptin are also morbidly obese and respond to leptin treatment,demonstrating that enhancing or inhibiting leptin’s activities in vivo may have potential therapeutic benefits. 展开更多
关键词 LEPTIN OB-R HYPOTHALAMUS adipose tissue obesity diabetes cytokine receptor
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Investigation of Essential or Non-essential Character of Some Hardly Known Trace Elements for Plants
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作者 Andras S. Szabo 《Journal of Life Sciences》 2015年第2期47-50,共4页
The concentration distribution of essential and non-essential micro-elements of the tissues of healthy organisms shows significant difference. This fact can be used for clarification of the biological role of hardly k... The concentration distribution of essential and non-essential micro-elements of the tissues of healthy organisms shows significant difference. This fact can be used for clarification of the biological role of hardly known trace elements, as well, proving the essential or non-essential character. In case of essential elements the concentration range is rather narrow, the distribution is normal. In case of non-essential elements the interval is wide, the concentration-distribution is log-normal. Measurements and mathematical calculations were carried out for determination of the concentrations and concentration-distributions of some micro-elements, trying to clarify the essentiality or non-essential character of the investigated elements from point of view of plant physiology. Based on the measurements for radish Li and Ni seem to be non-essential trace elements, however in case of Sr the distribution curve suggests an essential character, because the concentration range is not wide. 展开更多
关键词 Biological role concentration-distribution mathematical analysis MICROELEMENTS RADISH
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Relationship between Mutations in DNA Sequences Loci Coding Pre-miRNAs and Genes Related to Biogenesis of SncRNAs with MiRNA Expression in Endometrial Carcinoma Tissues
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作者 Massimiliano Chetta Angela Cordella +3 位作者 Giuseppina Bruno Maurizio Guida Alessandro Weisz Maria Ravo 《Journal of Environmental Science and Engineering(B)》 2015年第7期372-379,共8页
Endometrial cancer (EC) is the most common and lethal gynaecological cancer type in Europe and in North America. Frequently EC arises more in the corpus proper and manifests as round, polypoid expansile masses, but ... Endometrial cancer (EC) is the most common and lethal gynaecological cancer type in Europe and in North America. Frequently EC arises more in the corpus proper and manifests as round, polypoid expansile masses, but it may also originate in the lower uterine segment or spread in endometrium with necrosis and hemorrhage. The analysis was performed using a custom panel containing all DNA sequences loci coding pre-miRNAs and genes related to biogenesis and regulation of sncRNAs in normal and tumor tissues extracted from 6 unrelated patients with endometrial carcinoma. The identified variations were correlated with mature miRNAs differentially expressed in the same normal and tumor endometrial tissues. The comparison analysis confirmed the high degree of cellular and genetic intratumoral heterogeneity with a temporal and spatial miRNA expression distribution in association with genomic variants identified. The classification of specific DNA mutations, onto the loci identified, should be suitable to characterize possible instability genome regions and help classification of tumors to ameliorate the clinical management of patients affected by endometrial carcinoma. 展开更多
关键词 Endometrial cancer pre-miRNAs sncRNA miRNA expression.
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