A dual sensor for real-time monitoring of glucose and oxygen

A dual glucose and oxygen sensor in a polymer format was developed. The dual sensor composed of a blue emitter as the glucose probe, a red emitter as an oxygen probe, and a yellow emitter as a built-in reference probe which does not respond to either glucose or oxygen. All the three probes were chemically immobilized in a polyacrylamide-based matrix. Therefore, the dual sensor possesses three well separated emission colors and ratiometric approach is applicable for analysis of the glucose and oxygen concentration at biological conditions. The sensor was applied for real-time monitoring of glucose and oxygen consumption of bacterial cells, Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis), and mammalian cells of mouse macrophage J774 and human cervical cancer HeLa cell lines. On the other hand, in order to achieve satisfactory sensing performance for glucose, compositions of the matrices among poly(2-hydroxyethyl methacrylate), polyacrylamide, and poly(6-aminohexyl methacrylamide) which is a linker polymer for grafting the glucose probe, were optimized.     

微波心律(HBR)与呼吸频率(BF)遥测监护仪的研制

本研究提出了一种以电磁波作为传感媒体的“微波心律(HBR)与呼吸频率(BF)遥测监护仪”的设计方案。使用该方案的实验样机已研制成功。本研究对样机的工作原理、微波系统和电路系统的结构以及信号处理方法等进行了说明。实验结果表明：使用喇叭天线，在与人体相距0．35m～1．0m的范围内，仪器可以稳定可靠地采集到人体的心律和呼吸频率信号。该项研究成果适用于：无法使用接触方式采集心律和呼吸频率信号的场合，例如遥测烧伤患者卧床时的心律和呼吸频率信号、使用因特网或移动通信设备采集患者的心律和呼吸信息等。     

Impression technique for the assessment of oedema: comparison with a new tactile sensor that measures physical properties of tissue

To measure tissue oedema, the impression technique and a new tactile sensor technique are compared and evaluated in a silicone rubber model and in an in vivo rat testis model. The principles of the two techniques differ in that the impression technique evaluates interstitial fluid flow FT and peak force F(0) when tissue is compressed, whereas the tactile sensor evaluates the hardness/softness or change in resonance frequency Δf when a vibrating rod is attached to tissue. Both techniques can detect changes in silicone hardness/softness or in hormone-induced changes of testes, interstitial fluid. Although both F(0) and FT are significantly correlated to Δf in the experiments, it is concluded that F(0) is the most promising impression parameter to give valuable information about the hardness of living tissue as compared with Δf. The comparison indicates that the impression technique in the most easy, to interpret, non-invasive tool to assess tissue oedema so far developed.     

一种新的微波热疗机输出功率定标方法

目的:针对目前微波热疗机所采用的功率定标方法中没有考虑辐射器的损耗的问题,设计一套测量微波热疗机实际输出功率的装置,提出一种新的对微波热疗机实际输出功率进行定标的方法.方法:利用控制系统控制磁控管阳极电流维持在某一预设值,利用小功率计测量由微波源产生的,经过同轴电缆的微波功率P_(同轴电缆).然后将辐射器接上同轴电缆,使辐射器辐射的微波被实验装置中的水完全吸收.通过测量水的温度变化计算出水吸收的微波能量.利用冷却速率计算实验装置散失的能量,最后由两者能量之和与时间的比例得出辐射器输出的功率P_(辐射器).与此同时,可由P_(同轴电缆)与P_(辐射器)的比值得出辐射器的效率η_(辐射器).结果:微波热疗机通过辐射器输出的实际微波功率与磁控管阳极电流的关系为:P_(辐射器)=2η_(辐射器)1,在不同阳极电流下,得出辐射器的效率为:η_(辐射器)=(34±1)%.结论:从实验结果得知,现行微波热疗机的功率定标方法是有缺陷的,它没有考虑辐射器的转换效率,因此它测量的不是微波热疗机输出的实际微波功率.而采用本文介绍的定标方法可以准确获得微波热疗机的实际输出功率.     

生物材料的微波效应与其含水量关系的研究

目的：探讨生物材料中不同含水量对微波的吸收作用的影响。方法：利用微波分光仪测量不同含水量的生物材料对微波的透射、反射与折射情况并与微波防护布料相比较。结果：生物组织材料含水量对微波的吸收呈正相关，而且还会对材料附近的微波场分布造成一定的影响。结论：小物组织材料的含水最是影响生物体内SAR大小的重要因索，必须给予重视。     

一种监测微波热疗机输出功率变化的方法与装置

目的:针对目前微波热疗机实际输出功率在使用过程中会缓慢衰减,功率测量过程相对复杂等问题,提出了一种新的对微波热疗机实际输出功率进行快速测量的方法,并设计了一套对微波热疗机实际输出功率进行快速监测的装置。方法:利用对称振子天线与截止频率较高的低势垒肖特基二极管组成功率传感器,并将该微波天线置于微波热疗机辐射器前方的某一个固定点,在不同微波功率下测量天线感应、并经过二极管检波后的电压,将得到的功率与电压间的函数关系保存在单片机系统中。利用此函数关系,通过测量二极管检波电压来监测微波热疗机实际输出功率。结果:利用研制的装置,在全功率范围内测量微波热疗机的实际输出功率,测量误差小于5%。结论:微波热疗机的实际输出功率与辐射器前方某固定位置上微波天线感应、并经过二极管检波后得到的电压之间存在一个固定的函数关系。完成该电压与功率的定标后,通过测量二极管检波电压,就可以方便、准确地测量出微波热疗机的输出功率,监测输出功率的变化。这将使技术人员能够及时对微波热疗机输出功率进行修正,从而确保微波热疗剂量的准确性与安全性。     

Analysis of the pharynx and the trachea by the acoustic reflection method in children: a pilot study

The acoustic reflection method (ARM) is based on the analysis of the reflection of acoustic waves. The aim of the study was to determine the feasibility of the ARM in healthy children, and the anthropometric parameters that were correlated with the minimum cross-sectional area (MCAv) of the upper airways. Fifty-nine children (age 2-18 years) participated to the study. The mean MCAv value were 1.47±0.15, 1.77±0.33, 1.80±0.23, 2.06±0.42, 2.19±0.37, and 2.22±0.29cm(2), in the 2-3, 4-6, 7-9, 10-12, 13-15, and 16-18 year age groups, respectively. The MCAv values correlated significantly with height, age, and weight, but in a stepwise multiple regression analysis, only height remained correlated with the MCAv (r=0.59, p<0.0001). The analysis of the upper airways by the ARM is feasible in children after 2 years of age and the MCAv values increase with height in childhood.     

Development of a highly responsive needle-type glucose sensor using polyimide for a wearable artificial endocrine pancreas

To produce a long-life, stable, miniature glucose sensor for a wearable artificial endocrine pancreas (WAEP), we developed a novel microneedle-type glucose sensor using polyimide, designated the PI sensor (outer diameter, 0.3 mm; length, 16 mm), and investigated its characteristics in vitro and in vivo. In the in vitro study, we tested the sensor in 0.9% NaCl solution with varying glucose concentrations and observed an excellent linear relationship between the sensor output and glucose concentration (range: 0–500 mg/100 ml). In in vivo experiments, the PI sensor was inserted into the abdominal subcutaneous tissue of beagle dogs (n = 5), and interstitial fluid glucose concentrations were monitored after sensor calibration. Simultaneously, blood glucose concentrations were also monitored continuously with another PI sensor placed intravenously. The correlation and time delay between subcutaneous tissue glucose (Y) and blood glucose concentrations (X: 30–350 mg/100 ml) were Y = 1.03X + 7.98 (r = 0.969) and 6.6 ± 1.2 min, respectively. We applied the new WAEP system/PI sensor and an intravenous insulin infusion algorithm developed previously for glycemic control in diabetic dogs. The use of the WAEP system resulted in excellent glycemic control after an oral glucose challenge of 1.5 g/kg (post-challenge blood glucose levels: 176 ± 18 mg/100 ml at 65 min and 93 ± 23 mg/100 ml at 240 min), without any hypoglycemia. Thus, we confirmed that our new PI sensor has excellent sensor characteristics in vitro and in vivo. The new WAEP using this sensor is potentially suitable for clinical application.     

Osmotic barrier properties of the rat peritoneal membrane

In this study the osmotic barrier characteristics of the rat peritoneal membrane were investigated. Fluid movements between the peritoneal cavity and the blood were measured following instillation of isotonic saline (control) and hypertonic solutions of NaCl, glucose, sucrose, raffinose and myoglobin (test solutions). Moreover, 5 and 8% albumin in NaCl were investigated. Osmotic transients were assessed using a simple volume recovery technique. Peritoneal osmotic conductances (i.e. products of peritoneal hydraulic conductances [L_PS] and solute reflection coefficients [s?]) were calculated from the differences in the rates of peritoneal fluid loss and in osmotic pressures between test solutions and the isotonic saline control solution. The osmotic conductance to glucose was estimated to be 1.63/l min^-1 mmHg^-1 m^-2 and that for albumin to be 59.6 μl min^-1 mmHg^-1 m^-2. Assuming an albumin s? of 0.9, the s? of glucose was estimated to be 0.025, in accordance with previous measurements for the cat peritoneal membrane. The osmotic conductances assessed here were compatible with an overal? peritoneal equivalent small pore radius of 47–48 Å, but could also be fitted to a three-pore model of peritoneal permselectivity, including a transcellular (ultra-small pore) pathway and a large pore pathway. The great discrepancy between peritoneal s? for small solutes and that for albumin obtained in this study indicates that small solute reflection coefficients are close to zero while that for albumin is not far from unity. Furthermore, the peritoneal hydraulic conductance (ultrafiltration coefficient) is large enough to allow for a substantial absorption of fluid directly into the plasma when the crystalloid osmotic pressures in blood and peritoneal dialysate are in equilibrium.     

Symmetric sensor for applanation resonance tomometry of the eye

Applanation resonance tonometry (ART) has been shown in a number of studies to be useful for measuring intraocular pressure (IOP). Data from in vitro laboratory bench testing, where the sensor was carefully centralised onto the cornea, has been very consistent with good precision in the determination of IOP. However, in a clinical study the unavoidable off-centre placement of the sensor against the cornea resulted in a reduced precision. The aim of this study was to evaluate a new design of the sensor with a symmetric sensor probe and a contact piece with a larger diameter. Two in vitro porcine eye experimental set-ups were used. One bench-based for examining position dependence and one biomicroscope-based set-up, simulating a clinical setting, for evaluating IOP_ART precision at seven different pressure levels (10–40 mmHg), set by connecting a saline column to the vitreous chamber. The reference IOP was recorded using a pressure transducer. There was no significant difference between four positions 1 mm off centre and the one centre position. The precision of the ART as compared with the reference pressure was ±1.03 mmHg (SD, n=42). The design improvement has enhanced the precision of the ART in the biomicroscope set-up to be in parity with bench test results from a set-up using perfect positioning. This indicates that off-centre positioning was no longer a major contributor to the deviations in measured IOP. The precision was well within the limits set by ISO standard for eye tonometers. Therefore, a larger in vivo study on human eyes with the ART should be performed.     

Pulse wave reflection at the collapsed segment of an artery in Riva-Rocci's method

Summary The contours of pressure and flow of a pulse wave arriving at the entrance of a collapsed segment of an elastic tube can be described by application of the basic laws of reflection. The collapsed segment acts like a valve. It is opened by the pressure of the pulse wave when the pressure within the tube becomes higher than the collapse pressure, i.e. the pressure exerted on the segment from outside. This opening of the collapsed segment suddenly changes the sign of the pulse wave reflection from positive to negative; thus a typical contour change of the pulse proximal to the segment is observed. The most obvious effect is a reduction of the pulse pressure. The extent of this reduction is a function of the collapse pressure.A typical example of this phenomenon can be observed in an artery proximal to the segment which is collapsed due to the pressure exerted by an inflated Riva-Rocci cuff. The effect is explained by the assumption that the sign of reflection changes when the pressure of the pulse wave crosses the level of the cuff pressure. This explanation is supported by the results of model experiments.     

微波联合抗生素治疗盆腔炎疗效观察

目的观察微波联合抗生素治疗盆腔炎的临床疗效。方法采用抗生素加微波治疗,对照组采用抗生素进行治疗,比较两组临床疗效。结果观察组30例治愈27例,好转2例。治愈率90.0%.总有效率96.67%。对照组30患者治愈24例,好转3倒,治愈率80.0%。总有效率90.0%。两组差异有统计学意义。结论微波联合抗生素治疗盆腔炎性的治疗效果肯定,值得基层医疗机构推广应用。     

A Simple Radioenzymatic Procedure for the Determination of Choline and Acetylcholine in Brain Regions of Rats Sacrificed by Microwave Irradiation

A rapid and sensitive radioenzymatic method for analysis of choline (Ch) and acetylcholine (ACh) concentrations in rat brain regions is described. The ACh content is obtained as the difference in Ch concentration between a hydrolysed and an unhydrolysed tissue sample. The ACh content was 16 ± 1.0 nmol/g in the cortex and 76 ± 2.4 nmol/g in the striatum, and the corresponding Ch values were 23 ± 2.5 and 33 ± 1.2.     

A Critical Investigation on the Occurrence of Microwave Effects in Emulsion Polymerizations

The existence of special microwave effects in the emulsion polymerization of styrene and methyl methacrylate with two different initiators is investigated. All the experiments are conducted in either Pyrex or silicon carbide reaction vessels employing a dedicated single‐mode microwave reactor and are monitored with a dual temperature‐measurement system consisting of an external infrared sensor and an internal fiber optical probe. The goal of this study is to study the influence of the electromagnetic field on both the decomposition rate of the radical initiators and on the emulsion polymerization itself. For both types of transformation, no direct influence of the electromagnetic field can be observed, therefore ruling out the occurrence of any type of specific or nonthermal microwave effects in these reactions.

     

Microwave cell death: Enzyme histochemical evaluation for metastatic carcinoma of the liver

We have reported that microwave cell death is a unique cell death preserving not only cell and nuclear shapes but also immunohistochemical antigenicity. However, their enzyme activity was lost, which indicated cell dysfunction and death. This peculiar observation implies that the microwave effect is likely an 'in situ' tissue fixation and that this type of cell death is morphologically different from cell death, by either oncosis or apoptosis, as previously known. To confirm whether this peculiar cell death was observed also in human tissue samples, we examined clinical samples from patients with metastatic liver cancer, which were treated with microwave irradiation. They were examined immunohistochemically for human Ki-67 antigen and proliferating cell nuclear antigen and enzyme histochemically for alkaline phosphatase, and the same morphological changes that were observed in microwave-treated rat liver were found. In conclusion, we believe that routine hematoxylin-eosin stain alone is not a suitable method to evaluate microwave treatment for cancer because microwave coagulation therapy-treated cells preserved their nuclei and cellular architectures, even after 3 months. For microwave-treated tumors, enzyme histochemistry is helpful to determine its effectiveness.     

A method for in situ measurement of ionic concentration in picoliter samples of renal tubular fluid

A method permitting rapid and frequent determination of the total ionic concentration in renal tubular fluid samples, by measuring sample electrical impedance, is described. No special electrodes or sophisticated equipment are required. Since picoliter volumes are sufficient for measurement, tubular fluid dynamics are not significantly disturbed by the sampling procedure. The sample is aspirated into the tip of the standard glass micropipette and its ionic concentration, in the range of 100–1000 mmol/l, can be determined by any sensitive impedance-measuring device. In the present studies the Wheatstone bridge of the Wiederhielm apparatus for pressure measurement in micropuncture studies was used for the purpose. The obvious limitation of the method is that the measurements do not include nonelectrolytes and cannot differentiate between individual ion species.     

On the Importance of Accurate Internal Temperature Measurements in the Microwave Dielectric Heating of Viscous Systems and Polymer Synthesis

The relationship among viscosity and microwave absorptivity of organic solvents/polymers, the stirring rate, and the resulting errors in temperature measurement upon microwave dielectric heating is investigated. For a set of common solvents and polymers covering a broad range of viscosities and microwave absorptivities significant variations in the temperatures simultaneously recorded by external infrared sensors and internal fiber‐optic probes are experienced. The implications of these apparent difficulties in establishing the genuine reaction temperature for microwave‐heated viscous reaction systems are evaluated for a ring‐opening polymerization and for the synthesis of a surfactant.     

不同标本中甲型肝炎病毒核酸检测方法的建立及应用

目的 建立水、贝类、血液及唾液中甲型肝炎病毒核酸RT-PCR检测方法.方法 加入一定量甲肝病毒到贝类、水、血液及唾液标本中,贝类经研磨后,PEG沉淀浓缩;水直接经PEG沉淀浓缩;以上标本及血液、唾液标本用Trizol试剂提取核酸,套式RT-PCR检测甲肝病毒核酸.引物位于甲肝病毒结构区VP1-2A区.结果病毒培养液中能检测到0.1 TCID50甲肝病毒;水、血清及唾液中能检测到1TCID50甲肝病毒;毛蚶中能检测到1-10TCID50甲肝病毒.某地甲肝病毒污染的水及患者血清标本中检测到了甲肝病毒核酸,并进行了序列分析比对.结论 本研究建立的不同标本中甲型肝炎病毒核酸RT-PCR检测方法,敏感、特异、快速,具有广泛的应用价值,将为甲肝的溯源研究及分子流行病学研究打下理论基础及提供技术支撑.     

经皮穿刺微波凝固联合替吉奥治疗胃癌肝转移的疗效观察

目的观察经皮穿刺微波凝固治疗（PMCT）术后联合替吉奥胶囊（S-1）治疗胃癌肝转移的疗效。方法选择本科2009年2月~2012年3月收治的56例胃癌根治术后肝转移患者,分为PMCT术后联合替吉奥组（实验组,n=28）和单用PMCT组（对照组,n=28）。实验组PMCT术后口服替吉奥胶囊每日50mg/m2,连续给药14d,停药7天,共化疗6个疗程。结果实验组和对照组治疗结束时完全缓解分别为64.28%（18/28）和32.14%（9/28）,部分缓解分别为25%（7/28）和21.42%（6/28）,稳定分别为7.14%（2/28）和32.14%（9/28）,有效率89.29%（25/28）和53.57%（15/28）,两组相比均有统计学差异（P〈0.05）。毒副反应主要为骨髓抑制、胃肠道反应等。结论胃癌根治术后肝转移患者PMCT术后联合替吉奥化疗可提高患者术后生存率且毒副反应较轻,是胃癌根治术后伴肝转移有益的辅助治疗方案。