激光联合紫外线治疗II 期、III期压疮患者的疗效观察

目的：研究激光联合紫外线治疗II期和III期压疮患者的疗效。方法：回顾性分析2010 年7 月至2014 年7 月我科收治的59 例II期和III 期压疮患者的临床资料,按照护理方式的不同分为对照组（30 例）和联合组（29 例）,对照组在基础治疗的基础上进 行传统护理,联合组在基础治疗的基础上加用激光联合紫外线护理,两组治疗14 天后,采用压疮愈合评估量表（PUSH）评分比较 两组疗效。结果：两组患者治疗后PUSH评分均降低,且联合组降低幅度显著高于对照组,差异均有统计学意义（P<0.001）。结论： 激光联合紫外线治疗对II期和III期压疮患者的恢复具有显著促进作用,值得推广使用。     

Compression-induced damage and internal tissue strains are related

Prolonged mechanical loading of soft tissues adjacent to bony prominences can lead to degeneration of muscle tissue, resulting in a condition termed pressure-related deep tissue injury. This type of deep pressure ulcers can develop into a severe wound, associated with problematic healing and a variable prognosis. Limited knowledge of the underlying damage pathways impedes effective preventive strategies and early detection. Traditionally, pressure-induced ischaemia has been thought to be the main aetiological factor for initiating damage. Recent research, however, proposes tissue deformation per se as another candidate for initiating pressure-induced deep tissue injury. In this study, different strain parameters were evaluated on their suitability as a generic predictive indicator for deep tissue injury. With a combined animal-experimental numerical approach, we show that there is a reproducible monotonic increase in damage with increasing maximum shear strain once a strain threshold has been exceeded. This relationship between maximum shear strain and damage seems to reflect an intrinsic muscle property, as it applied across a considerable number of the experiments. This finding confirms that tissue deformation per se is important in the aetiology of deep tissue injury. Using dedicated finite element modeling, a considerable reduction in the inherent biological variation was obtained, leading to the proposal that muscle deformation can prove a generic predictive indicator of damage.     

Comparison of pressure chamber and psychrometer estimates of leaf water potential in rice

Summary The need to compare pressure-chamber estimates of leaf water potential with a psychrometric method has been established for several crop species. We investigated this relationship for rice (Oryza sativa L.) as well as the need to protect leaves from water loss during sampling and measuring period in the pressure chamber. Two rice cultivars grown in containers on a clay-loam soil were stressed to varying degrees by withholding water. Fully expanded leaves were sampled for estimation of leaf water potential by the dew point hygrometer and pressure-chamber techniques. The same leaf was used in both methods allowing direct comparison. Additionally, two alternative methods of leaf handling for measurement by the pressure chamber technique were compared. Protection of leaf samples against water loss during excision, transport and handling was found to be more important at higher leaf water potentials (>−1.0 MPa). The two cultivars used appeared to differ in their response to protection of the leaf sample. These results serve to further caution pressure chamber users on extrapolating comparisons between the two measurement methods and between tissue handling techniques even within a crop species.     

Effects of pressure on swimming behavior in planula larvae of the coral Porites astreoides (Cnidaria, Scleractinia)

Mechanisms governing the behavior of coral planulae are not well understood, particularly those manifesting themselves between the time when the larvae are released and when they settle. Larvae from the hermatypic coral Porites astreoides Lamarck were exposed to different levels of hydrostatic pressure—103.4, 206.9, 310.3, 413.8, and 517.1 kPa (including ambient pressure). Data were collected at stops of the above pressures for 15 min each, respectively. This was done in both an increasing sequence and a decreasing one. When exposed to increases in pressure from 103.4 kPa, larvae swam upward (negative barotaxis) in a spiraling motion. Upon exposure to decreasing pressure from 517.1 kPa, larvae moved downward (positive barotaxis), but the magnitude of the vertical movement was much less than in the case of increasing pressure. This suggests that these larvae are more sensitive to increased pressure than decreasing pressure. High variance was also observed in the responses of these larvae at both the intra- and inter-colony levels. Thus, this behavioral trait is variable within the population. The trait may be genetically based, and thus may be susceptible to alteration by natural selection, although this remains to be demonstrated. This study is the first to document these behavioral mechanisms in coral larvae.     

Cell cultures as models of cardiac mechanoelectric feedback

Although stretch-activated currents have been extensively studied in isolated cells and intact heart in the context of mechanoelectric feedback (MEF) in the heart, quantitative data regarding other mechanical parameters such as pressure, shear, bending, etc, are still lacking at the multicellular level. Cultured cardiac cell monolayers have been used increasingly in the past decade as an in vitro model for the studies of fundamental mechanisms that underlie normal and pathological electrophysiology at the tissue level. Optical mapping makes possible multisite recording and analysis of action potentials and wavefront propagation, suitable for monitoring the electrophysiological activity of the cardiac cell monolayer under a wide variety of controlled mechanical conditions. In this paper, we review methodologies that have been developed or could be used to mechanically perturb cell monolayers, and present some new results on the acute effects of pressure, shear stress and anisotropic strain on cultured neonatal rat ventricular myocyte (NRVM) monolayers.     

MitoQ对高糖诱导的心肌细胞线粒体功能影响

目的:探讨MitoQ对高糖诱导的心肌细胞线粒体功能影响。方法:常规获取与纯化SD大鼠新生仔鼠心肌细胞,分为对照组、高糖组、实验组。对照组用含10%血清的DMEM培养基(5.5 mmol/L葡萄糖)培养;高糖组用含血清的高糖DMEM培养基(33mmol/L葡萄糖)培养;实验组用含血清的高糖DMEM培养基(33 mmol/L葡萄糖)和MitoQ。MTT法检测心肌细胞存活率,氯离子荧光探针检测细胞内氯离子浓度,流式细胞术检测各组心肌细胞凋亡率,超氧化物阴离子荧光染色检测心肌细胞活性氧(reactive oxygen,ROS)含量,利用ATP检测试剂盒检测心肌细胞中的ATP水平,Western blot法检测心肌细胞胱天蛋白酶3(caspase-3)蛋白水平。结果:与对照组相比,高糖组的心肌细胞增凋亡率、ROS产生、氯离子相对浓度均明显增加,ATP显著降低(P0.05),细胞内caspase-3蛋白表达显著上升(P0.05);与高糖组相比,实验组凋亡率降低,ROS产生、细胞内caspase-3蛋白表达均显著降低(P0.05)。结论:高糖会引起心肌细胞线粒体障碍,造成心肌细胞凋亡,MitoQ可降低细胞内ROS和caspase-3水平,抑制心肌细胞凋亡,改善心肌细胞线粒体功能。     

Nitric oxide and blood pressure in mice lacking extracellular-superoxide dismutase

Nitric oxide is a major vasorelaxant and regulator of the blood pressure. The blood vessels contain several active sources of the superoxide radical, which reacts avidly with nitric oxide to form noxious peroxynitrite. There are large amounts of extracellular-superoxide dismutase (EC-SOD) in the vascular wall. To evaluate the importance of EC-SOD for the physiology of nitric oxide, here we studied the blood pressure in mice lacking the enzyme. In chronically instrumented non-anaesthetized mice there was no difference in mean arterial blood pressure between wild-type controls and EC-SOD mutants. Extensive inhibition of nitric oxide synthases with N -monomethyl- l -arginine however resulted in a larger increase in blood pressure, and infusion of the nitric oxide donor nitrosoglutathione caused less reduction in blood pressure in the EC-SOD null mice. We interpret the alterations to be caused by a moderately increased consumption of nitric oxide by the superoxide radical in the EC-SOD null mice. One role of EC-SOD may be to preserve nitric oxide, a function that should be particularly important in vascular pathologies, in which large increases in superoxide formation have been documented.     

Study of intraarticular pressures in the elbow joints

The purpose of this study was to describe pressure originating in the six elbow articular compartments after muscular contractions. Ten cryopreserved cadaveric arms were dissected and the insertional tendons and capsuloligamentous tissues were preserved. The specimens were placed in a custom-made device. Elbow position was established at 90° flexion with the forearm in a neutral position and the wrist extended at 0°. Tekscan sensors sere used for measuring intraarticular pressures.Without loading the elbow, the humeroradial joint received the lowest pressure, and, among the humeroulnar joints, the highest pressure was found in the anterolateral compartment. After loading the epitrochlear muscles to the maximum (5.0 kg), the pressure increased in the anteromedial joint (0.6 kg to 3.3 kg) and decreased in the posteromedial and anterolateral joints (4.2 kg to 0.3 kg and 4.2 kg to 0.9 kg, respectively). After the same loading in the epicondylar muscles, the pressure increased in the anterolateral and humeroradial joints (4.2 kg to 8.2 kg and 0.2 kg to 1.0 kg respectively), but decreased in the posterolateral joint (3.4 kg to 1.0 kg). The pressure distribution patterns among the humeroulnar compartments depend on the muscle geometries and their origins. Understanding these patterns can be useful in applying physiotherapeutic treatments for reinforcement of different muscular groups in order to decrease pressure in certain articular compartments.     

Chronobiologically interpreted ambulatory blood pressure monitoring: past,present, and future

Research at the Halberg Chronobiology Center focused to a large extent on the monitoring of blood pressure (BP) and heart rate (HR). Self-measurements and later ambulatory BP monitoring yielded new knowledge of interest to basic science and clinical practice. After a brief review of BP measurement, we outline developments in methods of data analysis that paralleled technological advances in the measurement of BP. We review work done in cooperation with colleagues worldwide to illustrate how a chronobiological approach led to the mapping of spontaneous circadian and other rhythms for the derivation of refined reference values and to the assessment of response rhythms underlying chronotherapy. BIOCOS members work in different fields, spanning from cardiology and nutrition to obesity, diabetes, exercise physiology and rehabilitation, but all strive for “pre-habilitation”. The early recognition of increased risk can prompt the timely institution of prophylactic intervention. As technology continues to improve, studies on groups are complemented by longitudinal self-surveillance for health maintenance. Longitudinal records serve for the investigation of environmental influences on human physiology, the topic of chronomics. As current advances in technology and wireless communication will likely impact the future of healthcare, chronobiological methods and concepts should be an integral part of this seachange.     

Pressure sensing using a completely flexible organic transistor

In this paper, we report on pressure sensors based on completely flexible organic thin film transistors (OTFTs). A flexible and transparent plastic foil (Mylar) is employed both as substrate and gate dielectric. Gold source and drain electrodes are patterned on the upper side of the foil while the gate electrode lies on the opposite side; a vacuum-sublimed pentacene film is used as active layer. The pressure dependence of the output current has been investigated by applying to the gate side of the device a mechanical stimulus by means of a pressurized airflow. Experimental results show a reversible dependence of the current on the pressure. The data analysis suggests that the current variations are due to pressure-induced variations of mobility, threshold voltage and possibly contact resistance. The drain current variation is reproducible, linear and reversible even though it displays a hysteresis. Moreover, the sensor responds very fast to the mechanical stimulus (i.e. within tens–hundreds of milliseconds) but the time required to reach the steady state is much higher (tens–hundreds of seconds). Electrical characteristics with and without applied pressure have been carried out in air without any extra ad hoc read-out circuit or equipment.

The reported devices show potential advantages of flexibility of the structure, low cost and versatility of the device structure for sensor technologies. Many innovative and attractive applications as wearable electronics, e-textiles, e-skin for robots can be considered.