不同环境中应用猪眼玻璃体液成分浓度变化推断死亡时间的研究

目的 研究在不同环境中大出血死亡猪眼玻璃体液成分变化及其与死亡时间（postmorteminterval,PMI）的关系。方法 放血处死家猪后取192只猪眼随机分为A、B两组,分别在避光、温度（15±2）℃、湿度（50±5）%的空气中以及浸没于环境温度为（15±2）℃双蒸水的条件下放置2～96 h,采集玻璃体液,运用全自动生化检测仪、超高效液相色谱分析仪（Ultra Performance Liquid Chromatography,UPLC）检测K＋、Na＋、Cl–及次黄嘌呤（hypoxanthine,Hx）浓度;采用SPSS13.0统计软件对检测数据进行回归分析。结果 眼球置于空气中时,玻璃体液中K＋、Hx与PMI相关性较高,回归方程为：PMI=-11.467＋1.954[K＋]-0.017[K＋]2＋0.511[Hx]（R2=0.858）;眼球置于双蒸水时,玻璃体液中Na＋、Cl–与PMI相关性较高,回归方程为：PMI=144.439-1.636[Na＋]＋0.007[Na＋]2-0.961[Cl-]＋0.005[Cl-]2（R2=0.622）。结论 玻璃体液K＋、Hx浓度变化可作为推断死后位于空气中的尸体较为稳定的指标;玻璃体液Na＋、Cl–浓度变化可能对死后抛入淡水尸体的PMI推断具有参考价值。     

改性玻璃离子水门汀的研究进展

玻璃离子水门汀作为一种新型的齿科修复材料,因其具有与牙体粘接性强,对牙体刺激性小,可有效防龋等诸多优点,目前被广泛应用于口腔临床中的充填、粘结、洞基衬,牙本质过敏的治疗及暂封等。本文在简述玻璃离子水门汀发展历史的基础上,综述近年来改性玻璃离子水门汀的研究进展及发展前景。     

玻璃离子水门汀的研究进展

介绍了玻璃离子水门汀的最新研究进展,对每种水门汀的组成、固化和特点进行了论述,并介绍了玻璃离子水门汀的氟释放、与牙体组织的粘接和临床用途.     

玻璃离子水门汀短期力学性能的研究

通过分析比较不同温度下,放置在硅油、水和空气中的的玻璃离子水门汀的短期抗压强度。研究了玻璃离子水门汀的固化反应过程。37℃时,放置在空气中的试样24h后,其强度达到最大值,然后略有下降,并保持稳定;放置在水中的试样,其抗压强度呈持续、缓慢增加的趋势;硅油中的试样则呈持续、增加的趋势,但其增加速度明显高于水中的试样。20℃时,无论是空气或硅油中试样的抗压强度增加速度较37℃时明显降低,放置在空气中的试样30d后达到最大值。因此,水的扩散速度和保持对玻璃离子水门汀的力学性能具有十分重要的影响。     

改性玻璃离子水门汀应力松弛蠕变实验

文题释义：黏弹性力学：连续介质力学的重要分支,又称黏弹性理论,研究黏弹性物质的力学行为、本构关系及其破坏规律,以及黏弹性体在外力和其他因素作用下的变形和应力分布。聚合物、混凝土、金属、岩石、土壤、石油、肌肉、血液和骨骼等,在一定条件下既具有弹性性质又具有黏性性质,这种兼具弹性和黏性性质的材料称为黏弹性材料,含黏弹性固体与黏弹性流体,又可分为线性黏弹性体和非线性黏弹性体。线性黏弹性体的两种极端情况即为胡克体(遵循胡克定律)和牛顿流体(遵循牛顿粘性定律)。 生物力学：是应用力学原理和方法对生物体中的力学问题定量研究的生物物理学分支,其研究范围从生物整体到系统、器官(包括血液、体液、脏器、骨骼等),从鸟飞、鱼游、鞭毛和纤毛运动到植物体液的输运等。 物力学的基础是能量守恒、动量定律、质量守恒三定律并加上描写物性的本构方程。生物力学研究的重点是与生理学、医学有关的力学问题,依研究对象的不同可分为生物流体力学、生物固体力学和运动生物力学等。 背景：以往对改性玻璃离子水门汀的力学性能研究多以压缩、弯曲实验居多,关于玻璃离子水门汀加入锶羟基磷灰石后的应力松弛、蠕变实验研究鲜有报道。 目的：对比分析传统玻璃离子水门汀、复合树脂釉质粘接剂、改性玻璃离子水门汀的应力松弛、蠕变特性。 方法：按质量比15%向玻璃离子水门汀中加入掺锶羟基磷灰石,制备改性玻璃离子水门汀。制作改性玻璃离子水门汀、复合树脂釉质粘接剂与传统玻璃离子水门汀试样,3组各取10个试样进行应力松弛实验,另取10个试样进行蠕变实验。 结果与结论：①应力松弛实验7 200 s时,传统玻璃离子水门汀组应力下降了1.18 MPa,复合树脂釉质粘接剂组应力下降了1.39 MPa,掺锶羟基磷灰石复合玻璃离子水门汀组应力下降了1.38 MPa;传统玻璃离子水门汀组应力下降量小于掺锶羟基磷灰石复合玻璃离子水门汀组、复合树脂釉质粘接剂组(P < 0.05),掺锶羟基磷灰石复合玻璃离子水门汀组和复合树脂釉质粘接剂组应力下降量无差异(P > 0.05)。②蠕变实验7 200 s时,传统玻璃离子水门汀组应变上升了0.24%,复合树脂釉质粘接剂组应变上升了0.33%,掺锶羟基磷灰石复合玻璃离子水门汀组应变上升了0.32%;传统玻璃离子水门汀组应变上升量小于掺锶羟基磷灰石复合玻璃离子水门汀组、复合树脂釉质粘接剂组(P < 0.05),掺锶羟基磷灰石复合玻璃离子水门汀组试和复合树脂釉质粘接剂组应变上升量无差异(P > 0.05)。③结果表明,15%掺锶羟基磷灰石提高和改善了玻璃离子水门汀的黏弹特性,有利于其与黏结物体的黏结,有利于提高黏结强度。 ORCID: 0000-0003-1024-5733(丁洁) 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

玻璃离子水门汀与光固化复合树脂联合修复楔状缺损的临床体会

联合应用玻璃离子水门汀与光固化复合树脂修复楔状缺损,增强修复体与牙体硬组织的粘接性,减少牙髓刺激,提高修复成功率。方法将楔状缺损患者随机分成对照组和实验组。实验组为玻璃离子水门汀与光固化树脂联合应用修复楔装缺损,对照组应用光固化复合树脂直接修复缺损,对比两组疗效,并应用统计学方法对数据进行处理。结果实验组和对照组治疗成功率分别是90.8%和76.7%,经统计学分析,两者存在显著差异（P〈0.01）。结论玻璃离子与光固化复合树脂联合应用修复楔状缺损的效果优于光固化复合树脂直接修复。     

玻璃离子水门汀与光固化复合树脂联合修复楔状缺损的临床体会

联合应用玻璃离子水门汀与光固化复合树脂修复楔状缺损,增强修复体与牙体硬组织的粘接性,减少牙髓刺激,提高修复成功率.方法 将楔状缺损患者随机分成对照组和实验组.实验组为玻璃离子水门汀与先固化树脂联合应用修复楔装缺损,对照组应用光固化复合树脂直接修复缺损,对比两组疗效,并应用统计学方法对数据进行处理.结果 实验组和对照组治疗成功率分别是90.8%和76.7%,经统计学分析,两者存在显著差异(P<0.01).结论 玻璃离子与光固化复合树脂联合应用修复楔状缺损的效果优于光固化复合树脂直接修复.     

电磁波对细胞内外离子浓度影响的基本理论

磁波生物学非热效应的一个代表性事例是对离子 ,比如Ca2 穿越细胞膜的影响 ,从而导致细胞内外离子浓度比值发生变化。阐述电磁波对细胞离子浓度影响这一生物学非热效应的基本理论 ,以此为电磁波生物学非热效应机理研究提供理论基础。该基本理论基于两个角度 :一是物理学角度 ,即视生物组织和细胞膜为一般的电磁媒质 ,由物理学角度分析可看出 ,一定参数的电磁波可使细胞内外二价离子浓度的比值发生 10 -6量级的变化 ,这相当于正常细胞内外钙离子浓度在固有比值 10 -4 的基础上发生了 1%的变化 ,与细胞产生动作电位时需要细胞内外电荷密度的比值在固有的 10 -4 基础上发生 1%的变化比较 ,可知基于物理学角度 ,电磁波在引起生物学非热效应方面是有意义的 ;二是生物学角度 ,即视生物组织和细胞膜为特殊的生命物质 ,由生物学角度分析可看出 ,一定参数的电磁波可导致在 1秒钟内有 10 6量级的二价离子穿过细胞膜 ,与用趋化 (趋药 )性试验证明了的要使白细胞的生活状态发生有意义变化需要额外有 10 3 量级的分子通过细胞膜比较 ,可知基于生物学角度 ,电磁波在引起生物学非热效应方面也是有意义的 ,因为无论是细胞内外离子浓度的变化 ,还是电荷穿越细胞膜迁移所携带的信息都会改变细胞自身的生理和生化状态。     

激光照射加玻璃离子水门汀充填乳牙龋的临床初探

目的 观察Nd：YAG激光照射后玻璃离子水门汀充填乳牙龋的临床效果。方法 用Nd：YAG激光照射后玻璃离子水门汀充填龋洞定期复查。结果 治疗组92例乳牙龋中，成功74例．成功率80％；失败18例，失败率20％．疗效明显优于对照组。结论：Nd：YAG激光照射加玻璃离子充填治疗乳牙龋有较好疗效。     

新型带环固位性能：3个方向抗剪切强度及其玻璃离子的黏结**

背景：由于磨牙带环的固位强度高,所以在正畸过程中起着重要的支抗作用,但是传统的磨牙带环存在着诸多弊端。 目的：观察比较新型磨牙带环与传统磨牙带环的固位性能。 方法：将拔除的人第三恒磨牙随机分为2组,对照组设计为玻璃离子水门汀黏结传统带环,对带环垂直加载;实验组设计为树脂加强型玻璃离子水门汀黏结新型带环,于电子万能材料测试机上从3个方向(垂直向、近中向及远中向)对带环加载,使用超精密形状与尺寸测量仪测量两种带环的表面积,计算带环完全脱落的最大载荷值。 结果与结论：实验组的抗剪切强度高于对照组(P < 0.05)。实验组带环3个方向的抗剪切强度近、远中向组高于垂直组(P < 0.05)。结果证实,新型带环使用树脂加强型玻璃离子黏结,凸显了新型带环的优点,且其固位性能优于传统带环使用传统玻璃离子黏结,新型带环与磨牙黏结可发挥其支抗作用。     

Immune Profiling of T Cells Infiltrating Vitreous Humor in Tubercular Uveitis

Purpose: To assess cellular composition and local cytokine response in vitreous humor of tubercular uveitis.

Methods: Cells were collected from vitreous cassettes and peripheral blood of 8 tubercular uveitis and 5 control subjects, undergoing vitrectomy and analyzed by flow cytometry for cellular composition, activation status, proinflammatory cytokine expression, and uptake of TLR9 ligand, CpG ODN 2216.

Results: CD3 + T cells with equal proportion of CD4+ and CD8 + T cells formed major fraction of infiltrating cells. The vitreous humor showed higher expression of recent activation marker, CD69, and proinflammatory cytokines, IFN-γ and IL-17A, in CD4 + T cells as compared to peripheral blood. Lastly, intraocular CD4 + T cells showed reduced uptake of ODN 2216 than peripheral blood.

Conclusions: Our results indicate that local antigenic stimuli trigger T cell infiltration and activation of CD4 + T cells that are hyporesponsive to TLR9 stimulation. These infiltrating T cells might be responsible in further aggravating ocular inflammation.     

Hyaluronan and Chondroitin Sulfate Proteoglycans in the Supramolecular Organization of the Mammalian Vitreous Body

The mammalian vitreous gel is a specialized type of highly hydrated extracellular matrix, which is composed of interwoven networks of uronic acid-containing polyanionic macromolecules, (i.e., hyaluronan, versican, and IX collagen) and collagen fibrils. Hyaluronan comprises the vast majority of the uronic acid-containing molecules, which contributes to structure and function of vitreous in at least two ways: its unique biophysical and hydrodynamic properties influence the vitreous homeostasis and biomechanics; it is also a template for assembly of other extracellular macromolecules, for example, versican. The other uronic acid-containing molecules namely versican and IX collagen—two chondroitin sulfate (CS) proteoglycans—occur in the vitreous without significant quantitative variations among different mammalians but with some marked variations on the molecular size and sulfation pattern of their chondroitin sulfate side chains. The contribution of versican and IX collagen (through their protein and their CS side chains) to the supramolecular organization of the vitreous gel is poorly understood. However, versican having the ability to bind hyaluronan via its N-terminal and other binding partners via its C-terminal region can play a crucial role on the structural stability and functionality of the vitreous.     

基于PIC单片机的便携式X线机主控系统设计与实现

目的：配合已有的高压系统,以PICl8F8722为主控CPU设计了一套X线机的主控系统,实现便携式X线机的摄影功能。方法：以常规摄影用X线机的功能为基础,采用kV、mAs二个参数控制曝光过程,曝光容量3．5kW;采用64K串行EEPROM存储芯片,保存胖、中、瘦3种体位,每种体位20个人体部位的曝光条件,实现体位程序摄影;系统可选用中文或英文操作界面;9种出错报警显示出错代码和具体出错信息：可配备有线或遥控双手闸曝光。结果：该系统结合高压发生系统、成像装置构成的便携式X线机,能够实现曝光条件选择、曝光控制、曝光过程检测、出错报警等功能,具有体积小、自动化程度高、控制方便等优点;同时系统具备冷高压测试的软件功能,方便系统调试和维修;系统设计充分考虑主控系统的硬件应用环境,预留充分的功能通道,以满足系统升级或不同的高压系统对主控板的改进要求。结论：该系统为便携式X线机、移动式床旁X线机系统的实现提供一个有效的解决方案,也可成为现有X线机技术更新的可行方案。     

Comparison of Drug Concentrations in Human Aqueous Humor after the Administration of 0.3% Gatifloxacin Ophthalmic Gel, 0.3% Gatifloxacin and 0.5% Levofloxacin Ophthalmic Solutions

Purpose: To investigate the penetration of 0.3% gatifloxacin ophthalmic gel, 0.3% gatifloxacin ophthalmic solution and 0.5% levofloxacin ophthalmic solution into aqueous humor after topical application.Materials and Methods: Age-related cataract patients (150 eyes in 150 cases) receiving phacoemulsification were randomly divided into three groups: a 0.3% gatifloxacin gel group (n=50), a 0.3% gatifloxacin solution group (n=50), and a 0.5% levofloxacin solution group (n=50). Each group was administered one drop of gel or solution every 15 minutes for four doses. Aqueous samples were collected at different time points after the last drop. High pressure liquid chromatography (HPLC) was applied to determine the concentrations. The one-way ANOVA analysis was performed.Results: Our data indicated that the concentration of the gatifloxacin gel group was higher than that of the gatifloxacin solution group at all time points (P <0.05); moreover, the gatifloxacin gel group exhibited higher levels than the levofloxacin solution group at 120.0 min and 180.0 min (P<0.05). Furthermore, the gatifloxacin gel produced the highest concentration at 120.0 min, and the gatifloxacin and levofloxacin solutions reached their peak values at 60.0 min.Conclusions: 0.3% gatifloxacin ophthalmic gel application produced highest aqueous humor drug concentration, maintained the longest time, had the best penetration and bioavailability.     

Electron Probe Microanalysis of Potassium and Sodium in Clonogenic Culture of Human Neural Stem Cells

The mean potassium and sodium concentrations and distribution of potassium in clonogenic culture of human neural stem cells (neurosphere) were estimated by means of electron probe microanalysis. High sodium concentration was typical of undifferentiated cells. Potassium was irregularly distributed in the test structure. Our results confirm published data on heterogeneous morphological structure of neurospheres. __________ Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 140, No. 9, pp. 282–285, September, 2005     

The Effect of Potassium Concentration on Glycolysis in High and Low Potassium Dog Erythrocytes

The effect of potassium concentration on glycolysis was studied in the erythrocytes of Japanese Shiba dogs with high potassium (HK) and low potassium (LK) concentrations. When intracellular Na and K concentrations were changed in intact erythrocytes, lactate formation increased with increasing K concentration in both HK and LK dogs. In the reconstituted haemolysates, lactate formation, phosphofructokinase (PFK) and pyruvate kinase (PK) activities increased with increasing K concentration in both HK and LK dogs. These results suggest that glycolysis in erythrocytes of HK and LK dogs is dependent on K concentration because PFK and PK require K for their activities. In the reticulocytes of a LK dog possessing high K and low Na concentrations, PK and PFK activities were markedly elevated from the levels in mature erythrocytes and also dependent on K concentration. As in HK dog erythrocytes, high K concentration is required for glucose metabolism in LK dog reticulocytes. It is suggested that the glycolytic system of LK dog erythrocytes retains the potential to be stimulated with high K concentration even after cell maturation.     

基于人体血液常/微量元素含量的SVM癌症辅助诊断

支持向量机（Support vector machine,SVM）分类方法在实际二类分类问题的应用中显示出良好的学习和泛化能力,已被广泛地应用于许多研究领域。我们以癌症病人血液中6种元素（Ba,Ca,Cu,Mg,Se,Zn）的含量为研究对象,将SVM、最近邻法、决策树C4.5及人工神经网络等方法用于癌症病人和正常人的分类研究。研究表明：除C4.5的分类准确率保持不变之外,对数据的归一化处理能够提高SVM、KNN、ANN的分类效果。当使用线性核函数时,SVM通过5次交叉验证的最优平均分类准确率达到了95.95%,优于KNN（93.24%）、C4.5（79.93%）及ANN（94.59%）等分类器,表明该方法有望成为一种实用的癌症临床辅助诊断手段。     

Effects of the Potassium Channel Blocker Barium on Sodium and Potassium Transport in the Rat Loop of Henle In Vivo

In vitro evidence suggests that the 'recycling' of K(+) ions through luminal K(+) channels in the thick ascending limb of the loop of Henle (TALH) is essential for the normal operation of the luminal Na(+)-K(+)-2Cl(-) co-transporter. In the present study these channels were investigated in vivo by perfusing superficial loops of Henle in anaesthetised rats with and without the K(+) channel blocker barium. Using a standard perfusate, intraluminal barium (5 mmol l(-1)) reduced sodium reabsorption (J(Na)) from 1887 +/- 50 to 1319 +/- 53 pmol min(-1) (P < 0.001). When the experiment was repeated using a low-Na(+) perfusate, designed to inhibit reabsorption in the pars recta (the initial segment of the loop of Henle), a similar reduction in J(Na) was observed (from 698 +/- 47 to 149 +/- 23 pmol min(-1), P < 0.001), strongly suggesting that the effect of barium is localised to the TALH. The magnitude of the reduction in J(Na) during blockade of K(+) channels confirms the importance of K(+) recycling in facilitating Na(+) reabsorption in the TALH in vivo. However, the reduction in J(Na) was not associated with a fall in the K(+) concentration of the fluid collected at the early distal tubule. When bumetanide, an inhibitor of the Na(+)-K(+)-2Cl(-) co-transporter, was included in the low-Na(+) perfusate, net K(+) secretion was observed. Addition of barium to this perfusate reduced, but did not abolish, the secretion, suggesting that bumetanide-induced K(+) secretion results partly from paracellular transport. Experimental Physiology (2001) 86.4, 469-474.     

Influence of Sodium and Potassium Ions on Acid Production by Washed Cells of Streptococcus mutans Ingbritt and Streptococcus sanguis NCTC 7865 Grown in a Chemostat

A comparison was made of acid production by cells of Streptococcus mutans Ingbritt and S. sanguis NCTC 7865 that had been washed twice and incubated in different concentrations of sodium and potassium ions. Organisms were grown under defined conditions in a chemostat under both glucose limitation and glucose excess conditions at a dilution rate of 0.1 h⁻¹ (mean generation time, 6.9 h). Acid production after a pulse of glucose, sucrose, and fructose was measured by pH fall experiments and as a rate at pH 7.0. S. mutans produced more acid than S. sanguis as measured by either criterion, although statistically faster rates of acid production and lower terminal pH values were obtained when cells of both species were suspended in KCl rather than in NaCl, with 200 mM KCl resulting in the lowest terminal pH in pH fall experiments. Sodium ions inhibited acid production: 183 mM NaCl reduced the glycolytic rates of S. mutans and S. sanguis metabolizing glucose at pH 7.0 in 135 mM KCl by 39 and 33%, respectively. The most pronounced stimulatory effect of potassium on acid production was by washed cells of S. sanguis that had been grown under arginine and under phosphate limitation. The pH fell by a further 0.86 and 1.21 pH units, respectively, and to below the critical pH for enamel demineralization when these cells were metabolizing glucose in 135 mM KCl compared with the same concentration of NaCl. This enhancement of acid production was not due to potassium translocation, as had been suggested previously, because no movement of potassium ions across the cell membrane could be detected. An alternative explanation is proposed in which sodium ions are excluded from the cell at the expense of membrane energy, i.e., the proton motive force, which could otherwise be used for the transport of sugars.