经会阴实时三维盆底超声评估不同分娩方式对产后女性前腔室结构和盆膈裂孔的影响

摘要 目的：探讨经会阴实时三维盆底超声评估不同分娩方式对产后女性前腔室结构和盆膈裂孔的影响。方法：回顾性分析2015年1月至2019年10月在我院接受检查的100例产妇的诊治资料。根据分娩方式的不同,将患者分为经阴道分娩组（n=55）和剖宫产分娩组（n=45）。比较两组产妇在静息状态和Valsalva状态下的前腔室和盆膈裂孔超声参数。结果：在静息状态下,两组的膀胱颈位置、逼尿肌厚度、膀胱后角和尿道倾斜角相比无差异（P>0.05）。经阴道分娩组在Valsalva状态下的膀胱颈移动度和尿道旋转角均大于剖宫产分娩组,尿道内口漏斗形成率和膀胱膨出率均高于剖宫产分娩组（P<0.05）。在Valsalva状态下,经阴道分娩组的盆膈裂孔前后径、左右径、面积和周长均大于剖宫产分娩组（P<0.05）;在静息状态下,两组的上述指标相比,差异均无统计学意义（P>0.05）。结论：应用经会阴实时三维盆底超声技术观察产妇前腔室结构和盆膈裂孔的参数变化,可评估产妇盆底功能受损的程度,经阴道分娩对其影响较大。     

Measurement of bacterial random motility and chemotaxis coefficients: I. Stopped-flow diffusion chamber assay

Bacterial chemotaxis, the directed movement of a cell population in response to a chemical gradient, plays a critical role in the distribution and dynamic interaction of bacterial populations in nonmixed systems. Therefore, in order to make reliable predictions about the migratory behavior of bacteria within the environment, a quantitative characterization of the chemotactic response in terms of intrinsic cell properties is needed.The design of the stopped-flow diffusion chamber (SFDC) provides a well-characterized chemical gradient and reliable method for measuring bacterial migration behavior. During flow through the chamber, a step change in chemical concentration is imposed on a uniform suspension of bacteria. Once flow is stopped, diffusion causes a transient chemical gradient to develop, and bacteria respond by forming a band of high cell density which travels toward higher concentrations of the attractant. Changes in bacterial spatial distributions observed through light scattering are recorded on photomicrographs during a 10-min period. Computer-aided image analysis converts absorbance of the photographic negatives to a digital representation of bacterial density profiles. A mathematical model (part II) is used to quantitatively characterize these observations in terms of intrinsic cell parameters: a chemotactic sensitivity coefficient, mu(0), from the aggregate cell density accumulated in the band and a random motility coefficient, mu, from population dispersion in the absence of a chemical gradient.Using the SFDC assay and an individual-cell-based mathematical model, we successfully determined values for both of these population parameters for Escherichia coli K12 responding to fucose. The values obtained were mu = 1.1 +/- 0. 4 x 10(-5) cm(2)/s and chi(o) = 8 +/- 3 +/- 10(-5) cm(2)/s. We have demonstrated a method capable of determining these parameter values from the now validated mathematical model which will be useful for predicting bacterial migration in application systems.     

Air humidity as key determinant of morphogenesis and productivity of the rare temperate woodland fern Polystichum braunii

(1) Most ferns are restricted to moist and shady habitats, but it is not known whether soil moisture or atmospheric water status are decisive limiting factors, or if both are equally important. (2) Using the rare temperate woodland fern Polystichum braunii, we conducted a three‐factorial climate chamber experiment (soil moisture (SM) × air humidity (RH) × air temperature (T)) to test the hypotheses that: (i) atmospheric water status (RH) exerts a similarly large influence on the fern's biology as soil moisture, and (ii) both a reduction in RH and an increase in air temperature reduce vigour and growth. (3) Nine of 11 morphological, physiological and growth‐related traits were significantly influenced by an increase in RH from 65% to 95%, leading to higher leaf conductance, increased above‐ and belowground productivity, higher fertility, more epidermal trichomes and fewer leaf deformities under high air humidity. In contrast, soil moisture variation (from 66% to 70% in the moist to ca. 42% in the dry treatment) influenced only one trait (specific leaf area), and temperature variation (15 °C versus 19 °C during daytime) only three traits (leaf conductance, root/shoot ratio, specific leaf area); RH was the only factor affecting productivity. (4) This study is the first experimental proof for a soil moisture‐independent air humidity effect on the growth of terrestrial woodland ferns. P. braunii appears to be an air humidity hygrophyte that, whithin the range of realistic environmental conditions set in this study, suffers more from a reduction in RH than in soil moisture. A climate warming‐related increase in summer temperatures, however, seems not to directly threaten this endangered species.     

In vitro Biofilm Formation in an 8-well Chamber Slide

The chronic nature of many diseases is attributed to the formation of bacterial biofilms which are recalcitrant to traditional antibiotic therapy. Biofilms are community-associated bacteria attached to a surface and encased in a matrix. The role of the extracellular matrix is multifaceted, including facilitating nutrient acquisition, and offers significant protection against environmental stresses (e.g. host immune responses). In an effort to acquire a better understanding as to how the bacteria within a biofilm respond to environmental stresses we have used a protocol wherein we visualize bacterial biofilms which have formed in an 8-well chamber slide. The biofilms were stained with the BacLight Live/Dead stain and examined using a confocal microscope to characterize the relative biofilm size, and structure under varying incubation conditions. Z-stack images were collected via confocal microscopy and analyzed by COMSTAT. This protocol can be used to help elucidate the mechanism and kinetics by which biofilms form, as well as identify components that are important to biofilm structure and stability.     

The efferent innervation of the genital chamber by an identified serotonergic neuron in the female cricket Acheta domestica

Summary The serotonergic innervation of the genital chamber of the female cricket, Acheta domestica, has been investigated applying anti-serotonin (5-HT) immunocyto-chemistry at both light- and electron-microscopic levels as well as using conventional electron microscopy. Whole mount and pre-embedding chopper techniques of immuno-cytochemistry reveal a dense 5-HT-immunoreactive network of varicose fibers in the musculature of the genital chamber. All of these immunoreactive fibers originate from the efferent serotonergic neuron projecting through the nerve 8v to the genital chamber (Hustert and Topel 1986; Elekes et al. 1987). At the electron-microscopic level, 5-HT-immunoreactive nerve terminals, which contain small (50–60 nm) and large ( 100 nm) agranular vesicles as well as granular vesicles (100nm), contact the muscle fibers or the sarcoplasmic processes without establishing specialized neuromuscular connections. In addition to the 5-HT-immunoreactive axons, two types of immunonegative axons can also be found in the musculature. By use of conventional electron microscopy, three ultrastructurally distinct types of axon processes can be observed, one of which resembles 5-HT-immunoreactive axons. While the majority of the varicosities do not synapse on the muscle fibers, terminals containing small (50–60 nm) agranular vesicles occasionally form specialized neuromuscular contacts. It is suggested that the 5-HTergic innervation plays a non-synaptic modulatory role in the regulation circular musculature in the genital chamber of the cricket, while the musculature as a whole may be influenced by both synaptic and modulatory mechanisms.Fellow of the Alexander von Humboldt-Stiftung     

Direct and indirect effects of elevated CO2 on transpiration from Quercus myrtifolia in a scrub-oak ecosystem

Elevated atmospheric carbon dioxide (C_a) usually reduces stomatal conductance, but the effects on plant transpiration in the field are not well understood. Using constant‐power sap flow gauges, we measured transpiration from Quercus myrtifolia Willd., the dominant species of the Florida scrub‐oak ecosystem, which had been exposed in situ to elevated C_a (350 µmol mol ^{? 1} above ambient) in open‐top chambers since May 1996. Elevated C_a reduced average transpiration per unit leaf area by 37%, 48% and 49% in March, May and October 2000, respectively. Temporarily reversing the C_a treatments showed that at least part of the reduction in transpiration was an immediate, reversible response to elevated C_a. However, there was also an apparent indirect effect of C_a on transpiration: when transpiration in all plants was measured under common C_a, transpiration in elevated C_a‐grown plants was lower than that in plants grown in normal ambient C_a. Results from measurements of stomatal conductance (g_s), leaf area index (LAI), canopy light interception and correlation between light and g_s indicated that the direct, reversible C_a effect on transpiration was due to changes in g_s caused by C_a, and the indirect effect was caused mainly by greater self‐shading resulting from enhanced LAI, not from stomatal acclimation. By reducing light penetration through the canopy, the enhanced self‐shading at elevated C_a decreased stomatal conductance and transpiration of leaves at the middle and bottom of canopy. This self‐shading mechanism is likely to be important in ecosystems where LAI increases in response to elevated C_a.     

Energy expenditure in relation to activity of lesser mouse deer (Tragulus javanicus)

Heat production (HP) of male and female mouse deer during eating, standing and sitting was determined using the open circuit respiration chamber (RC). The time taken for similar activities was also determined in an outdoor enclosure (OD). The animals were fed kangkong (Ipomoea aquatica), sweet potato (Ipomoea batatas) and rabbit pellet ad libitum. Male mouse deer consumed more dry matter (DM), organic matter (OM) and gross energy (GE) than female. The time for each activity of male and female mouse deer kept in RC and OD was similar. The average time spent in RC and OD for both male and female, respectively, for sitting (956 and 896 min/day) was significantly (P<0.01) longer than standing (463 and 520 min/day) and eating (21 and 24 min/day). Heat production for male and female mouse deer, respectively, during eating was the highest (0.44 and 0.43 kJ/kg W^0.75/min) followed by standing (0.37 and 0.33 kJ/kgW^0.75/min) and sitting (0.26 and 0.26 kJ/kg W^0.75/min). The difference in HP per min during standing between male and female was significant (P<0.05). The HP for 08.00–14.00 h and 14.00–20.00 h periods were higher than 20.00–02.00 h and 02.00–08.00 h periods. The overall HP for males during 08.00–14.00 h and 14.00–20.00 h periods were significantly (P<0.05) higher (114.8 and 119.2 kJ/kg W^0.75) than female (107.5 and 110.4 kJ/kg W^0.75), respectively.     

银杏胚珠贮粉室的早期发育

对银杏 (GinkgobilobaL .)胚珠贮粉室的早期发育过程以及珠心细胞死亡的细胞学机制进行了研究。DNA电泳出现DNAladder和TUNEL标记说明参与形成贮粉室的珠心细胞死亡是程序性死亡 (PCD)过程 ,并且显示出在贮粉室形成中 ,PCD的发生有一定的空间分布式样。结合扫描电镜观察 ,贮粉室的早期发育可分为 4个阶段 :起始事件是位于珠孔端的 3至 4层珠心细胞纵向伸长 ;接着 ,位于珠心组织最上部 (珠孔端 )的珠心细胞启始死亡 ;然后 ,这些已经纵向伸长的珠心细胞向基地和侧向地逐渐死亡 ,形成一个空腔 ;最后 ,珠孔端珠心表皮细胞以开裂的方式与其余表皮细胞脱离而形成贮粉室的开口。大孢子母细胞时期 ,贮粉室尚未发生 ;四分体阶段 ,贮粉室已经开始形成 ;到雌配子体发育时期 ,贮粉室已经完全产生。反映大孢子发育和贮粉室发生的同步性。