英夫利西单抗对炎症性肠病患者肠道菌群的影响

目的 :分析英夫利西单抗对炎症性肠病(Inflammatory bowel disease,IBD)患者肠道菌群结构的影响。方法 :以我院2012年6月—2014年6月收治的28例IBD患者为研究对象,均给予英夫利西单抗治疗,观察其治疗30周后肠道菌群变化、症状评分变化及临床疗效和不良反应。结果 :UC患者治疗前肠球菌、葡萄球菌、酵母菌、拟杆菌、双歧杆菌、乳杆菌、消化球菌、小梭菌数量显著高于正常组,其真杆菌数量低于正常组;CD患者治疗前肠球菌、酵母菌、拟杆菌、双歧杆菌、乳杆菌、消化球菌数量显著高于正常组,其真杆菌、小梭菌数量低于正常组,差异有统计学意义(P<0.05)。治疗后UC患者及CD患者肠道菌群结构与正常组比较,差异无统计学意义(P>0.05)。患者治疗6周后、治疗30周后改良Mayo评分及CDAI评分均显著下降,差异有统计学意义(P<0.05)。治疗30周后,UC患者有效率为90.0%,CD患者有效率为87.5%。患者治疗期间不良反应发生率32.1%,其不良反应以注射部位皮疹、皮肤瘙痒为主。结论 :英夫利昔单抗能够调节IBD患者肠道菌群结构失衡状态,改善患者临床症状。     

应用肠道解痉剂对结肠息肉检出率的影响

目的:分析使用肠道解痉剂对结肠息肉检出率的影响。方法:1592例接受肠镜检查者,注射东莨菪碱的559例为观察组,未使用肠道解痉剂的1033例为对照组,比较两组患者结肠息肉检出率。结果:两组受试者进镜时间、退镜时间、不良反应发生率比较,差异无统计学意义(P>0.05)。观察组结肠息肉检出率为97.37%,高于对照组的82.33%,肠道蠕动程度弱于对照组,差异均有统计学意义(P<0.05)。结论:使用肠道解痉剂对于提高结肠息肉检出率具有积极意义,且无明显副作用。     

飞秒激光烧蚀不锈钢的实验研究

进行了飞秒激光烧蚀不锈钢(SUS420)的工艺实验研究。采用波长为780nm,脉宽为164fs,频率为1k Hz的飞秒激光照射不锈钢。对比分析了长短脉冲激光烧蚀不锈钢的作用过程,计算了单脉冲飞秒激光烧蚀不锈钢的烧蚀阈值和烧蚀阈值随脉冲数量改变的累计系数,研究了不同激光参数烧蚀不锈钢的工艺规律。结果表明:飞秒激光烧蚀金属材料的过程中对加工区域周围具有较小的热影响;单脉冲飞秒激光烧蚀不锈钢的烧蚀阈值为0.25J/cm2,烧蚀阈值随脉冲数量改变的累计系数为0.68;飞秒激光脉冲能量对烧蚀孔孔径的增加比较明显,脉冲数量对烧蚀孔孔深的增加比较显著。     

急性心肌梗死心电图aVR导联ST段改变与梗死冠脉数量及预后的相关性

目的 :分析急性心肌梗死心电图aVR导联ST段改变与梗死冠脉数量及预后的相关性。方法 :选取医院2016年8月至2019年2月收治的464例急性心肌梗死患者进行研究,根据心电图aVR导联ST段改变情况进行分组,比较抬高组、无偏移组和下移组冠脉病变数量、梗死相关血管和不良心血管事件发生情况。结果 :抬高组与下移组冠脉病变数量以三支病变为主,发生率高于无偏移组,而无偏移组以单支病变为主,发生率高于抬高组与下移组,差异有统计学意义(P<0.05)。抬高组梗死相关血管以左主干和左前降支近端为主,占比明显高于无偏移组与下移组,下移组以左回旋支为主,占比明显高于抬高组与无偏移组,差异均有统计学意义(P<0.05)。抬高组与下移组心力衰竭、心因性死亡、恶性心律失常和非致病性心肌再梗发生率均高于无偏移组,差异有统计学意义(P<0.05)。结论 :aVR导联ST段改变可能提示三支病变和不良预后,其中抬高可能提示左主干和左前降支近端病变,下移可能提示左回旋支病变。     

肠道驻留机构的设计和实验

研究并设计了一种微型肠道驻留机构以实现胃肠道机器人在人体肠道特殊环境下的有效驻留。该驻留机构采用径向伸出三组腿的方式实现扩张,扩张后三组腿仍然处于封闭状态,从而有效降低了肠道组织被夹住的风险。对驻留机构与肠道之间的相互作用进行了建模分析,并将驻留机构的驻留力分为库伦摩擦力和边缘阻力两部分,分析了其产生机理。通过实验测试了驻留机构的扩张力以及驻留力。实验结果表明:驻留机构的扩张力与理论分析较为接近,驻留力大小与肠道直径、驻留腿扩张直径以及驻留机构速度有关。当驻留腿的扩张直径为20~26mm时,驻留力大小为0.15~0.4N;当驻留腿扩张直径大于26mm时,驻留力迅速增加,为0.5~1.8N。设计的肠道驻留机构体积小、安全,可较好地适应肠道的生理环境,并为肠道诊疗微型机器人驻留机构的设计提供了一种新的思路。     

新型肠道机器人动力学建模和参数优化研究

针对人体肠道粘液为非牛顿流体的特点,推导了非牛顿流体的变形雷诺方程,建立了肠道机器人在人体肠道中运动的数学模型。采用有限差分法分析了肠道机器人螺旋槽参数对机器人动压粘液膜承载量、轴向摩擦牵引力和周向摩擦阻力的影响,从而获得了一组相对最优的机器人螺旋槽参数,使得肠道机器人可获得较大的动压粘液膜承载量和轴向摩擦牵引力,同时减小了其周向摩擦阻力。     

体内微机构与动物肠道摩擦实验研究

采用了一组不同材料、直径、长度、质量的微机构样本,在动物离体肠道中进行了摩擦实验。通过实验数据分析了微机构外壳的材料和尺寸对动物肠道摩擦力大小的影响。实验结果表明:在肠道中,密度较小的材料比密度大的材料具有更好的润滑性能,因此更适于作为医用微机构外壳的材料。另外,直径对于摩擦力也具有较为明显的影响,长度则影响不大。微机构的质量是影响负载的又一重要因素,在设计时应避开使负载达到最大值的微机构质量值。     

汽轮机高压旁路翼型阀芯调节阀调节特性

高压旁路调节阀是汽轮机高压旁路系统中最重要的构成部分,本文针对某300MW汽轮机组高压旁路系统调节阀,利用NACA6409翼型上表面型线为其设计了一种翼型结构的阀芯。利用数值模拟方法研究了不同进口水蒸汽参数和减温水喷淋参数条件下,阀腔内压力、温度以及液相体积分数分布特征,并研究了阀芯开度对高压旁路调节阀内部流场的影响,最后研究减温水喷射孔数量和布置方式的改变对阀腔内流场参数以及减温减压效果的影响。     

探讨电镜包埋时间对脂肪组织超微结构的影响

目的 :本文主要分析和探讨透射电镜制样技术中的包埋时间对脂肪组织超微结构观察的影响。方法 :自C57BL/6J小鼠完成白色脂肪和棕色脂肪组织取材,常规电镜样品处理,放置于磷酸盐缓冲液后分成三组进行包埋,分别于第2天、第7天和第14天进行组织包埋、切片,观察不同包埋时间下白色和棕色脂肪组织光镜和电镜下组织细胞结构的变化。结果 :脂肪组织放置于缓冲液中,第二天包埋后脂肪组织内的白色脂肪细胞和棕色脂肪细胞呈圆形或椭圆形,胞膜完整光滑,胞浆内脂滴呈圆形。随着包埋时间的延后,脂肪细胞呈不规则形,部分区域见细胞崩解,细胞膜可见断裂、褶皱和串珠样改变,脂滴形态改变。结论 :脂肪组织制作透射电镜标本时取材后应及时进行包埋处理,不宜在缓冲液内长时间浸泡。     

活动期溃疡性结肠炎患者凝血指标变化及其临床指导价值

目的:观察活动期溃疡性结肠炎(Ulcerative colitis,UC)患者凝血指标变化,探讨其临床指导价值。方法:自我院2014年3月—2016年10月活动期UC患者中选取172例(A组),同期缓解期UC患者选取90例(B组)、50名健康体检者(NC组)。检测各组受试者血小板计数(PLT)、平均血小板体积(MPV)、凝血酶原时间(PT)等凝血指标;此外,按照活动期UC患者病情活动度,分别纳入轻度组(n=63)、中度组(n=41)、重度组(n=68),对各组凝血指标进行比较,并计算凝血指标与活动期UC患者疾病活动指数(CAI)、Baron内镜评分的相关性,总结凝血指标变化在活动期UC病情严重程度评估的临床价值。结果:活动期UC组PLT、FIB、D-D高于其他2组,其MPV、PT低于其他2组;活动期UC组、B组PT低于NC组,差异有统计学意义(P<0.05)。随着患者病情活动度的加剧,其PLT、D-D逐渐上升,MPV逐渐下降;其轻度组FIB低于中度组、重度组,差异有统计学意义(P<0.05)。Pearson相关性分析提示,PLT、D-D与CAI指数、Baron内镜评分呈正相关,MPV与CAI指数、Baron内镜评分呈负相关(P<0.05)。结论:检测活动期UC患者PLT、D-D及MPV变化能够为病情活动度及严重程度的判断提供一定参考。     

The mushroom bodies of Drosophila melanogaster: an immunocytological and golgi study of Kenyon cell organization in the calyces and lobes

Golgi impregnations reveal a variety of dendritic morphologies amongst Kenyon cells in the mushroom bodies of Drosophila melanogaster. Different morphological types of Kenyon cells contribute axon-like processes to five divisions of the medial and vertical lobes. Four of these divisions have characteristic affinities to antibodies raised against aspartate, glutamate, and taurine. A newly described posterior subdivision of the medial lobe, here named the betac lobe with its vertical branch alphac, comprises glutamatergic Kenyon cells that are probably homologous to glutamatergic Kenyon cells in the cockroach and honey bee, and are the last neurons to differentiate. The first neurons to differentiate, which supply the gamma lobe, are equipped with clawed dendritic specializations and are the structural homologues of clawed class II Kenyon cells supplying the gamma lobes in cockroaches and honey bees. Three intermediate divisions lie between the betac lobe and gamma lobe. These are, from the back towards the front, the beta lobe, the beta' lobe, and a narrow division between beta' and gamma called the beta" lobe. The fused calyx of the Drosophila mushroom body is comparable to the double calyces of Hymenoptera, here exemplified by a basal taxon, Diprion pini. Further similarities between the hymenopteran calyces and those of Drosophila are suggested by the segregation of different types of Kenyon cell dendrites within the calyx neuropil. The organization of afferents from the antennal lobes also defines regions in the Drosophila calyx that may be homologous to the lip and basal ring regions of the honey bee calyces. As in honey bees, GABAergic processes densely invade Drosophila's calyces, which also contain a sparse but uniform distribution of octopaminergic elements. Microsc. Res. Tech. 62:151-169, 2003.     

In vitro and in situ experimental model for X-ray microanalysis of intestinal epithelium

Intestinal chloride (Cl) transport is disturbed in a number of diseases. X-ray microanalysis can be used to study the distribution of Cl and other ions in intestinal epithelial cells. In this study it was attempted to establish an experimental system that retains the in vivo elemental composition of intestinal epithelial cells. An in vitro system was set up in which a segment of rat intestine was mounted in a bath and perfused with different fluids. The chloride in the bath or in the perfusion fluid could be exchanged for gluconate or bromide to determine the direction of chloride fluxes. An in situ system was set up in which the animal was anesthetized and a segment of the intestine was perfused with different solutions. In the in vitro experiments the concentration of Na and Cl in the epithelial cells increased and that of K decreased. These changes occurred within the first 30 minutes of incubation. Uptake of chloride occurred mainly from the bath, as seen in experiments where bromide was used as a chloride analog. The concentration gradient between bath and tissue determined the extent of chloride uptake. Addition of glucose to the perfusion fluid and bath did not improve the results. In the in situ system, preservation of the intracellular ion composition was better. Acceptable results were obtained with perfusion with Krebs-Ringer's buffer without glucose for 30 minutes. In this case, the elemental content of the cell did not change appreciably during incubation. If glucose was added, the Na concentration increased in comparison to the control, both in crypt and villus cells. It is concluded that the intestinal epithelium is a sensitive system, very prone to disturbance of its homeostasis. However, the in situ system can be used in studies of agonist-induced ion transport.     

Increasing axial resolution of 3D data sets using deconvolution algorithms

Deconvolution algorithms are tools for the restoration of data degraded by blur and noise. An incorporation of regularization functions into the iterative form of reconstruction algorithms can improve the restoration performance and characteristics (e.g. noise and artefact handling). In this study, algorithms based on Richardson-Lucy deconvolution algorithm are tested. The ability of these algorithms to improve axial resolution of three-dimensional data sets is evaluated on model synthetic data. Finally, unregularized Richardson-Lucy algorithm is selected for the evaluation and reconstruction of three-dimensional chromosomal data sets of Drosophila melanogaster. Problems concerning the reconstruction process are discussed and further improvements are proposed.     

Expression mosaic of odorant-binding proteins in Drosophila olfactory organs.

Deciphering the genome of the fruitfly, Drosophila melanogaster, has revealed 39 genes coding for putative odorant-binding proteins (OBPs), more than are known at present for any other insect species. Using specific antibodies, the expression mosaic of five such OBPs (OS-E, OS-F, LUSH, PBPRP2, PBPRP5) on the antenna and maxillary palp has been mapped in the electron microscope. It was found that (1) OBP expression does correlate with morphological sensillum types and subtypes, (2) several OBPs may be co-localized in the same sensillum, and (3) OBP localization is not restricted to olfactory sensilla. The expression of PBPRP2 in antennal epidermis sheds some light on the possible evolution of OBPs.     

Development of PDF-immunoreactive cells,possible clock neurons,in the housefly Musca domestica

Even though the housefly Musca domestica shows clear circadian rhythms in its behavioural and physiological processes, a circadian pacemaker system controlling these rhythms has not yet been described morphologically in this species. In M. domestica, neurons immunoreactive to pigment-dispersing factor (PDF), a neurotransmitter/neuromodulator of circadian information arising from a circadian clock and transmitted to target cells, are similar in their number and distribution to the PDF neurons of Drosophila melanogaster. In D. melanogaster these neurons co-localize PER protein and have been identified as clock neurons in that species. Here we report PDF-immunoreactive cells in the housefly's brain during postembryonic development in the larval and pupal stages, as well as in the adult fly soon after eclosion. In the housefly's brain, there are three groups of PDF-immunoreactive neurons: two groups with small (sPDFMe) and large (lPDFMe) cell bodies in the proximal medulla of the optic lobe; and one group in the dorsal protocerebrum (PDFD). Three out of four sPDFMe can be detected during the first hour of larval development, but the fourth sPDFMe is observed in the larva only from 48 hours after hatching, along with five lPDFMe neurons, seen first as two subgroups, and three out of four PDFD neurons. During postembryonic development these neurons show changes in their structure and immunoreactivity. New PDF neurons are observed during pupal development but these neurons mostly do not survive into adulthood. In the adult fly's brain, the PDF neurons have also been examined in double-labelled preparations made with a second antibody directed against the product of one of several clock genes: period (per), timeless (tim), or cryptochrome (cry). Among them, only immunoreactivity to CRY-like protein has been detected in the brain of M. domestica and has shown a daily rhythm in its concentration, as examined immunocytochemically. CRY was co-localized with PDF in the sPDFMe of the housefly's brain fixed during the day. The possibility that the sPDFMe neurons are the housefly's clock neurons is discussed.     

Human cell models to study small intestinal functions: recapitulation of the crypt-villus axis

The intestinal epithelium is continuously and rapidly renewed by a process involving cell generation, migration, and differentiation, from the stem cell population located at the bottom of the crypt to the extrusion of the terminally differentiated cells at the tip of the villus. Because of the lack of normal human intestinal cell models, most of our knowledge about the regulation of human intestinal cell functions has been derived from studies conducted on cell cultures generated from experimental animals and human colon cancers. However, important advances have been achieved over recent years in the generation of normal human intestinal cell models. These models include (a) intestinal cell lines with typical crypt cell proliferative noncommitted characteristics, (b) conditionally immortalized intestinal cell lines that can be induced to differentiate, and (c) primary cultures of differentiated villuslike cells that can be maintained in culture for up to 10 days. Each of these models should help in the investigation of the specific aspects of human intestinal function and regulation. Furthermore, taken together, these models provide an integrated system that allows an in vitro recapitulation of the entire crypt-villus axis of the normal human small intestine.     

Determining structure/function relationships for sarcomeric myosin heavy chain by genetic and transgenic manipulation of Drosophila

Drosophila melanogaster is an excellent system for examining the structure/function relationships of myosin. It yields insights into the roles of myosin in assembly and stability of myofibrils, in defining the mechanical properties of muscle fibers, and in dictating locomotory abilities. Drosophila has a single gene encoding muscle myosin heavy chain (MHC), with alternative RNA splicing resulting in stage- and tissue-specific isoform production. Localization of the alternative domains of Drosophila MHC on a three-dimensional molecular model suggests how they may determine functional differences between isoforms. We are testing these predictions directly by using biophysical and biochemical techniques to characterize myosin isolated from transgenic organisms. Null and missense mutations help define specific amino acid residues important in actin binding and ATP hydrolysis and the function of MHC in thick filament and myofibril assembly. Insights into the interaction of thick and thin filaments result from studying mutations in MHC that suppress ultrastructural defects induced by a troponin I mutation. Analysis of transgenic organisms expressing engineered versions of MHC shows that the native isoform of myosin is not critical for myofibril assembly but is essential for muscle function and maintenance of muscle integrity. We show that the C-terminus of MHC plays a pivotal role in the maintenance of muscle integrity. Transgenic studies using headless myosin reveal that the head is important for some, but not all, aspects of myofibril assembly. The integrative approach described here provides a multi-level understanding of the function of the myosin molecular motor.     

双刀并行数控车削中的切削参数优化方法

为优化双刀并行车削中的切削参数,降低加工成本,提出了结合蚁群算法和子问题枚举算法的切削参数优化算法。以最小化加工成本为目标函数,以粗精车削两阶段的切削参数为决策变量,建立了双刀并行车削的切削参数优化模型;根据车削加工的特点,将参数优化问题分解成若干个子问题,并推导出相应的加工成本理论下限,从而有效降低问题的复杂度。模拟结果表明,该算法运算效率高,能快速找到优化的车削参数,从而节约加工成本。     

The neuroarchitecture of the circadian clock in the brain of Drosophila melanogaster

Neuroethologists try to assign behavioral functions to certain brain centers, if possible down to individual neurons and to the expression of specific genes. This approach has been successfully applied for the control of circadian rhythmic behavior in the fruit fly Drosophila melanogaster. Several so-called "clock genes" are expressed in specific neurons in the lateral and dorsal brain where they generate cell-autonomous molecular circadian oscillations. These clusters are connected with each other and contribute differentially to the control of behavioral rhythmicity. This report reviews the latest work on characterizing individual circadian pacemaker neurons in the fruit fly's brain that control activity and pupal eclosion, leading to the questions by which neuronal pathways they are synchronized to the external light-dark cycle, and how they impose periodicity on behavior.