快速微波热声层析成像在生物医学中的潜在应用

介绍了一种快速热声层析成像方法和装置,成功实现了生物组织的二维热声层析成像及异物检测.实验中采用频率为1.2 GHz的脉冲微波作为激发源,中心频率为3.5 MHz的320振元线性阵列探测器接收热声信号,然后用有限场滤波反投影方法重建得到热声层析图像.与原有方法相比,勿需全方位扫描采集数据,能大量节省时间,重建图像的对比度和抗噪声能力有极大提高.该方法和系统有望应用于乳腺癌早期检测、体内异物检测、微波热疗效果监测等方面.     

Body Size and Reproductive Tactics in Varanid lizards

Body size and female reproduction in the water adult females larger than 500 mm SVL and 32 adult males Ledong, Hainan under permit to our laboratory in Hainan monitor lizard （Varanus salvator） were studied. Forty-two larger than 400 mm SVL were donated by local people in in 2013 and 2014. The largest male and female measured 745 and 755 mm SVL, respectively. The mean SVL was greater in adult females than in adult males. Males had larger heads （head width） than females of the same SVL. The smallest reproductive female in our sample was 565 mm SVL. Females produced a single clutch of 17.1 （10-23） pliable-shelled eggs per breeding season stretching from mid-June and mid-September. Clutch size and clutch mass were all positively related to female SVL. However, there was no significant linear relationship between egg mass and female SVL. Larger females generally produced more eggs, and thus heavier clutches than did smaller ones. There was no significant linear relationship between relative clutch mass and female SVL. Phylogenetic generalized least squares （PGLS） analysis, accounting for phylogenetic relationships, showed that clutch size was positively correlated with mean maternal SVL in varanid lizards. PGLS analysis showed that phylogenetic relationships did not affect clutch （or/and egg） mass and the SVL although there were significant linear relationship between clutch （or/and egg） mass and mean maternal SVL. Therefore, we could draw some general conclusions about the body size and reproductive tactics in varanid lizards that larger females generally produced more eggs, larger eggs and thus heavier clutches than did smaller ones.     

Incubation failure and nest abandonment by Leach's Storm‐Petrels detected using PIT tags and temperature loggers

ABSTRACT The nocturnal activity of burrow‐nesting seabirds, such as storm‐petrels and shearwaters, makes it difficult to study their incubation behavior. In particular, little is known about possible differences in the incubation behavior of adults at successful and unsuccessful nests. We combined the use of passive integrated transponder (PIT) technology and nest‐temperature data loggers to monitor the incubation behavior of 10 pairs of Leach's Storm‐Petrels (Oceanodroma leucorhoa). The mean incubation bout length was 3.31 ± 0.59 (SD) days for individual adults at successful nests (N= 4) and 1.84 ± 1.16 d for individuals at unsuccessful nests (N= 6). Mean bout length for pairs in successful burrows (3.51 ± 0.56 d) did not differ significantly (P= 0.07) from that for pairs in unsuccessful burrows (1.80 ± 1.20 d), perhaps due to one failed nest with a high mean bout length (4.15 d). The total number of incubation bouts per parent (4.3 ± 1.9 bouts) did not differ with hatching success. Adults whose nests failed repeatedly exhibited truncated incubation bouts (< 12 h) prior to complete nest failure and were more likely than successful parents to make brief visits to nearby, occupied nesting burrows. Our results suggest that the decision by Leach's Storm‐Petrels to abandon a nest is not an abrupt one. Rather, failed nesting attempts may be characterized by truncated incubation bouts where individuals pay the energetic cost of travel to and from the burrow, but do not remain long enough to successfully incubate the egg.     

Newest approaches to quantitative assessment of bioactive organotins

Abstract

New approaches for assessing the toxicity of organotin chemical species have been developed. These approaches are based upon the selective responses of sensitive biodetectors whose chemical and molecular interactions with a wide variety of toxicants have been previously determined and reported. Bioassays capable of quantitating and chemically speciating toxicants for impacts on diverse bacterial sensors are discussed herein. The principal new development is a laser/bacterial bioassay which is capable of differentiating between various toxic chemicals and specifically distinguishing between the different organotin species based on their mechanism of toxic action. The system uses a battery of isogenic Bacillus subtilis strains genetically engineered to respond differentially to specific toxicants. The response is monitored by differential light scattering of a laser which is integrated with a computerized system that collects and analyzes the data. The system routinely generates fully analyzed data within 66 min for most samples. It is capable of making 1,200 measurements on each sample within 2 to 4 seconds, and shows promise as a rapid and inexpensive system to monitor organotins and various other toxicants on site.     

采用基因微阵列技术对常见呼吸道病毒进行检测的初步研究

建立一种高通量的基因微阵列检测技术,对常见呼吸道病毒感染进行监控.根据公开发表的8个病毒科38种常见呼吸道病毒的序列,计算其保守区域,设计病毒的特异性检测探针,制备呼吸道病毒检测基因微阵列.利用随机引物PCR方法标记样品中的病毒靶序列,标记产物与基因微阵列上的探针杂交,清洗、扫描后进行结果分析.采用流感病毒、麻疹病毒、腮腺炎病毒和风疹病毒作为报告病毒,并对80例上呼吸道感染患者的咽拭子标本进行验证测试.初步结果表明,该呼吸道病毒微阵列基因芯片检测是可行的,在利用基因微阵列技术对病毒监控方面进行了有益的尝试,得到了有经验的信息.     

湖南壶瓶山国家级自然保护区华南湍蛙种群监测

2004年5～11月,在湖南壶瓶山国家级自然保护区,采用标志一重捕法对华南湍蛙种群进行了生态监测,结果发现,华南湍蛙出蛰以后种群开始增加,繁殖期过后种群开始下降。在壶瓶山当气温低于10℃以下时,华南湍蛙就开始进入冬眠期。种群的存活率从出蛰到再次冬眠期间基本上呈直线下降,在8月之前种群中均有新添加的数量,以后未发现。在整个过程中,雌雄性比一般大于1,在繁殖季节基本接近于1。     

运动员心功能评估新方法和新指标的研究

目的：探讨无创检测和评估心功能的新指标和新方法。方法：随机抽取81名体育系学生（买验组,n=81）和41名普通系学生（对照组,n=41）,完成规定运动量的台阶运动后,通过采集心音信号,进行了心率,D／S比值以及S1／S2比值的对照研究。结果：在静息状态下,体育系学生的心率为66．2±8．7,D／S比值为2．04±0．33;晋通系学生的心率为70．8±8．0,D／S比值为1．82±0．27;在全运动量下,体育系学生的S1／S2比值为7．34±4．04;普通系学生的S1／S2比值为5．22±2．38。,结论：体育系学生比普通系学生具有较高水平的心脏储备：该方法可用来评估运动员与一般人的心脏储备,为运动员选拔以及一般人体质评估提供一种客观量化的新指标。     

Cellular homeostatic tension and force transmission measured in human engineered tendon

Tendons transmit contractile muscular force to bone to produce movement, and it is believed cells can generate endogenous forces on the extracellular matrix to maintain tissue homeostasis. However, little is known about the direct mechanical measurement of cell-matrix interaction in cell-generated human tendon constructs. In this study we examined if cell-generated force could be detected and quantified in engineered human tendon constructs, and if glycosaminoglycans (GAGs) contribute to tendon force transmission. Following de-tensioning of the tendon constructs it was possible to quantify an endogenous re-tensioning. Further, it was demonstrated that the endogenous re-tensioning response was markedly blunted after interference with the cytoskeleton (inhibiting non-muscle myosin-dependent cell contraction by blebbistatin), which confirmed that re-tensioning was cell generated. When the constructs were elongated and held at a constant length a stress relaxation response was quantified, and removing 27% of the GAG content of tendon did not alter the relaxation behavior, which indicates that GAGs do not play a meaningful role in force transmission within this system.     

门诊血液透析事件监测软件的开发与应用

为加强医院门诊血液透析事件的监控,设计开发了门诊血液透析事件监测软件,对血液透析事件进行实时监测和统计分析,实现了门诊血液透析事件的信息化监测和数据的即时共享,提高了医院感染目标性监测和干预的质量和效率。     

Enhanced fibroblast contraction of 3D collagen lattices and integrin expression by TGF-beta1 and -beta3: mechanoregulatory growth factors?

Generation of contractile forces as fibroblasts attach and migrate through collagenous substrates is a fundamental behavior, yet its regulation and consequences are obscure. Although the transforming growth factor-betas (TGF-beta) are similarly important in fibrosis and tissue repair, their role in contraction is controversial. Using a quantitative, 3D collagen culture model we have measured the effects of TGF-beta1 and -beta3 on contractile forces generated by human dermal fibroblasts. Maximal stimulation was between 7.5 and 15 ng/ml of TGF-beta1. Higher doses were inhibitory (30 ng/ml), giving a bell-shaped dose response. The initial rate of force generation was increased sevenfold (15 ng/ml). A similar response pattern was seen with TGF-beta3 alone. However, the addition of both isoforms together stimulated a biphasic increase in force generation, suggesting that there was a distinct temporal cooperativity between the two isforms. This very early onset (10-20 min) of stimulation suggested that TGF-beta might act through cell attachment and integrin function and the effect of TFG-beta on expression of fibronectin (FnR) and vitronectin (VnR) integrin receptors was monitored over the same time scale. TGF-beta1 dramatically up-regulated VnR expression, relative to FnR, over time but the optimal time for this was 2-4 h later than that of force stimulation. It is concluded that TGF-beta1 and -beta3 behave here primarily as mechanoregulatory growth factors and that stimulation of integrin expression may be a consequence of the altered cell stress.