The use of potassium iodide equilibrium density gradient centrifugation in the purification of RNA for hybridization with nonreiterated DNA sequences.

A new instrument has been developed that is able to monitor enzyme activities in chromatography column eluents automatically. The instrument consists of a simple stopped-flow instrument, equipped with a multishutoff valve to direct reagents and eluent flow. Assays of the eluate may be done at present intervals. The instrument may also be used for monitoring enzyme activities in perfasates as well as for monitoring the elution of metabolites.     

嵌入式AFP测试仪的设计

介绍了一个嵌入式AFP测试仪的设计。测试仪以嵌入式微处理器LPC2210为核心,主要包括数据采集、步进电机的驱动及人机交互界面等几部分。测试仪可通过RS232与PC机通讯,进行数据处理及报告分析,具有一定的临床辅助诊断价值。     

数字PCR仪校准方法研究

数字PCR仪是核酸绝对定量的重要仪器,因此确保数字PCR仪检测结果的准确性十分重要。通过对国内市场上数字PCR仪的比较分析,剖析了数字PCR仪的性能指标,对数字PCR仪的校准方法进行了探讨,设定了拷贝数浓度相对示值误差、拷贝数浓度重复性、荧光通道一致性和反应单元个数重复性作为数字PCR仪整机校准的计量技术指标,采用具有溯源性的国家有证标准物质,对方法进行了试验验证。验证结果表明了校准思路和方法的可行性,该方法操作性强,能够满足仪器技术要求以及用户需求, 提高了数字PCR仪检测结果的准确性和可靠性,对进一步拓展和深化数字PCR 技术的应用具有积极的促进作用。     

准分子激光眼科治疗机中激光器控制实现

准分子激光眼科治疗机可以用来进行近视、远视、散光等屈光不正的矫正手术。其中激光器的控制为手术提供能量稳定的激光脉冲,是对手术安全性、可靠性的重要保证。本文简述了一准分子激光眼科治疗机的整体组成部分,并详细描述了激光器的控制部分:计算机与激光器的通信控制、激光发射停止控制、充换气流程控制。目前,这种准分子激光治疗机已经应用于临床,并取得了良好的效果。     

数据记忆动物游泳测试仪的研制

目的研制一种用于检测动物负载游泳状况及过程的仪器,用于动物疲劳游泳试验。方法采用不同直径的可调换加载钢球、恒温水池、接近传感器信号转换、51系列单片微机控制和记忆信号。结果研制出一台可同时做六路平行实验的动物游泳测试仪,自动记忆动物在加载的情况下抗疲劳游泳的全过程。结论经36例小鼠实验证明,效果良好,该仪器为动物负载游泳实验提供了一种全新的测试方法。     

An instrument for assessment of videotapes of general practitioners' performance.

OBJECTIVES--To identify those important characteristics of doctors'' and patients'' behaviour that distinguish between "good" and "bad" consultations when viewed on videotape; to use these characteristics to develop a reliable instrument for assessing general practitioners'' performance in their own consultations. DESIGN--Questionnaires completed by patients, general practitioner trainers, and general practitioner trainees. Reliability of draft instrument tested by general practitioner trainers. SETTING--All vocational training schemes for general practice in the Northern region of England. SUBJECTS--First stage: 76 patients in seven groups, 108 general practice trainers in 12 groups, and 122 general practice trainees in 10 groups. Second stage: 85 general practice trainers in 12 groups. MAIN OUTCOME MEASURES--Trainers'' ratings of importance; alpha coefficients of draft instrument by trainee, group, and consultation. RESULTS--6890 characteristics of good and bad consultations were consolidated into a draft assessment instrument consisting of 46 pairs of definitions separated by six point bipolar scales. Nine statement pairs given low importance ratings by trainers were eliminated, reducing the instrument to 37 statement pairs. To test reliability, general practitioner trainers used the instrument to assess three consultations. With the exception of one group of trainers, all alpha coefficients exceeded the acceptable level of 0.80. CONCLUSION--The instrument produced is reliable for assessing general practitioners'' performance in their own consultations.     

多光束中医信息治疗仪的研制

本文介绍了一种应用光子中医学技术防治缺血性疾病的多光束弱激光中医信息治疗仪。该仪器将先进的单片计算机技术,激光技术与光子中医信息疗法融为一体。文章主要介绍了多光束中医信息治疗仪的设计理念及其实现方式。     

生态治理政策工具对农户行为的影响差异研究——以宁夏盐池县为例

政策工具被认为是政府为解决某个公共问题采取的具体手段或措施,一项政策可以视作目标和多种政策工具的组合。在生态治理过程中,不同政策工具对农户行为的刺激程度不同,进而导致不同的政策效果。分离不同政策工具的影响,可为工具选择和政策优化提供科学参考。以盐池县为例,利用基于该县1983-2017年内出台的316份生态政策文本构建的政策工具数据集和VAR模型中的脉冲响应和方差分解方法定量研究了强制型、混合型和自愿型三大类政策工具及十种子工具对农户耕作、放牧、造林3种行为的影响。结果表明：（1）政策工具对农户行为的影响具有时效性,一般在政策出台后2-3年内影响最大,随后逐渐减小并消失,影响持续时间为7-10年。（2）总体来看,政策工具对农户行为的冲击力度较小,冲击范围在0-0.30之间,说明农户行为还受到其他诸多因素的影响。（3）10年累计影响从大到小依次为强制型、混合型、自愿型,其中直接提供和规制两种子工具的影响最大。放牧行为受到政策工具的刺激最大,耕作行为次之,造林行为最小。（4）直接提供工具对耕作行为具有最大正向影响,最大冲击为0.30;规制工具在短期内抑制牲畜数量增长,而直接提供和补贴工具促进牲畜数量增长,且由于冲击曲线存在正负波动,说明政府与农户在牲畜养殖上存在长期博弈;只有规制工具对造林行为具有积极影响,说明造林更多是在政府的主导下进行。建议充分利用政策工具的短期效应,凸显政府角色,及时做好政策效果评估工作,调整工具组合,助力生态目标的实现。     

Construction of a scale to signal personality disorders in the elderly

Till now, no specific diagnostic instruments to detect personality disorders in the elderly are available. The aim of our study was to contribute to the construction of a reliable en valid instrument for the detection of personality disorders in older adults. Therefore, a draft version of the instrument was constructed both for the patient and the informant. Both the patient and the informant version of the instrument included 52 items with the same content. These items concerned Habitual behaviour (HAB), Biographical information (BIO) and Observation of actual behaviour (OBS). 159 clients of 60 years and older of a Dutch ambulatory mental health care organisation were assessed with the screening instrument. In 96 of the 159 outpatients one or more informants were included. The results indicate that the internal consistency of seven HAB items, nine BIO items and five OBS items was moderate to good with regard to both the patient and informant instrument. Test-retest reliability of the 21 items of the patient instrument was moderate with regard to HAB, excellent with regard to BIO and moderate with regard to OBS. Interrater reliability of OBS was also moderate. The criterion validity (criterion: DSM-IV TR Axis II classification) of HAB, BIO and OBS based on the 21 items of the patient instrument was fair and with regard to the same 21 items of the informant instrument insufficient. In conclusion, sixteen out of 52 potential items of the patient's draft version of the screening instrument can be used to detect a possible personality disorder. These sixteen items from the HAB and BIO scale are named the Gerontological Personality disorder Scale (GPS). Medical doctors, psychologists and nurses working in ambulatory mental health organisation can use the GPS as a resource during the diagnostic process. Whether the GPS can be used beyond mental health organisations, for example by general practitioners is a subject for future studies.     

Design of a multifunctional compliant instrument for minimally invasive surgery

A new multifunctional compliant instrument has been designed for use in minimally invasive surgery. The instrument combines scissors and forceps into a single multifunctional device. The main advantage of using multifunctional instruments for minimally invasive surgery is that instrument exchanges can be reduced, thus reducing procedure time and risk of inadvertent tissue injury during instrument exchanges. In this paper, the length, width, and thickness of the multifunctional compliant mechanism tool tip is optimized to maximize the jaw opening and the grasping force. The optimized design is then modeled to simulate the stresses encountered in the scissors mode. A 5.0 mm diameter stainless steel prototype is fabricated using electro-discharge machining and is shown to grasp and cut successfully.     

A simple and biosafe method for isolation of human umbilical vein endothelial cells

Human umbilical vein endothelial cells (HUVEC_S) are used as an irreplaceable tool for the study of vascular diseases. However, the technicians who isolate HUVECs are largely exposed to potential infectious threats. Here we report the development of a specialized instrument to protect researchers from known or unknown infectious agents when they operate on human umbilical cords. This instrument can be assembled by common laboratory supplies and adapted to accommodate umbilical cords of different lengths. When the cord is enclosed within the instrument, the risk of sample contamination and operator infection is greatly reduced. Using our instrument, endothelial cells were successfully isolated from human umbilical veins without contamination. The cells were verified by their cobblestone-like morphology and by immunofluorescence staining (Factor VIII and CD31 positivity and α-SMA negativity). Our instrument simplifies and optimizes the cell extraction process, and most importantly elevates the biosafety to a higher level during the isolation of human umbilical vein endothelial cells.     

2种不同器械扩锉后根管壁的细菌学研究

目的通过对临床病例的研究,比较减速镍钛机扩和普通不锈钢K型锉清洁根管的能力。方法选取临床需要根管治疗的患牙60例,随机分为2组,经开髓拨髓后分别用镍钛减速机扩和不锈钢K型及H型锉进行根管预备,预备完成后用灭菌棉捻擦拭管壁,作微生物检查。结果2组方法扩锉后对根管内微生物的变化做统计学分析,差异有显著性(P<0.05)。结论镍钛减速机扩对根管的清洁能力高于普通不锈钢扩锉,值得临床的推广。     

Controlled rate freezing of human marrow in a constant temperature cooling gradient in air

A new instrument which utilizes a computer controlled freezing platform moving in a constant air temperature gradient generated over liquid nitrogen (LN2) was evaluated for cryopreservation of human marrow. Marrows were placed horizontally on the freezing platform which was suspended over LN2 in a cylindrical freezing chamber. The platform was raised or lowered to maintain a predetermined fixed cooling rate in response to temperature monitored and recorded by the computer from a thermocouple placed at platform level. Separate freezing programs were created for different marrow volumes. The viability of normal marrow was tested in vitro before and after freezing. Recovery of marrow cells after freezing and thawing, as measured by cell counts and CFU-GM assays, were the same for the constant air gradient instrument as for a conventional freezing instrument. Thirteen patients received autologous marrow transplants utilizing marrow cryopreserved in the constant air gradient instrument and engraftment results were indistinguishable from those obtained for marrow cryopreserved with a conventional instrument.     

自记录动物挂杠持久度测试装置的研制

目的：研制一种检测动物挂杠持久度的实验装置,用于相关医药研究中的动物静态抗疲劳实验。方法采用51系列单片微机控制和记忆,光耦传感器、电磁水阀等组合控制电路和技术。结果成功研制出一种适用于医学及药学研究领域的带微机控制和自记忆功能的动物挂杠持久度实验装置,经28例小白鼠实验证明,效果良好。结论该实验装置为动物抗疲劳实验提供了一种全新的方法。     

Environmental Profile of a Community's Health (EPOCH): an instrument to measure environmental determinants of cardiovascular health in five countries

BACKGROUND: The environment in which people live is known to be important in influencing diet, physical activity, smoking, psychosocial and other risk factors for cardiovascular (CV) disease. However no instrument exists that evaluates communities for these multiple environmental factors and is suitable for use across different communities, regions and countries. This report describes the design and reliability of an instrument to measure environmental determinants of CV risk factors. METHOD/PRINCIPAL FINDINGS: THE ENVIRONMENTAL PROFILE OF COMMUNITY HEALTH (EPOCH) INSTRUMENT COMPRISES TWO PARTS: (I) an assessment of the physical environment, and (II) an interviewer-administered questionnaire to collect residents' perceptions of their community. We examined the inter-rater reliability amongst 3 observers from each region of the direct observation component of the instrument (EPOCH I) in 93 rural and urban communities in 5 countries (Canada, Colombia, Brazil, China and India). Data collection using the EPOCH instrument was feasible in all communities. Reliability of the instrument was excellent (Intraclass Correlation Coefficient--ICC>0.75) for 24 of 38 items and fair to good (ICC 0.4-0.75) for 14 of 38 items. CONCLUSION: This report shows data collection with the EPOCH instrument is feasible and direct observation of community measures reliable. The EPOCH instrument will enable further research on environmental determinants of health for population studies from a broad range of settings.     

An instrument capable of imaging chlorophyll a fluorescence from intact leaves at very low irradiance and at cellular and subcellular levels of organization

An instrument capable of imaging chlorophyll a fluorescence, from intact leaves, and generating images of widely used fluorescence parameters is described. This instrument, which is based around a fluorescence microscope and a Peltier-cooled charge-coupled device (CCD) camera, differs from those described previously in two important ways. First, the instrument has a large dynamic range and is capable of generating images of chlorophyll a fluorescence at levels of incident irradiance as low as 0.1 μmol m^?2 s^?1. Secondly, chlorophyll fluorescence, and consequently photosynthetic performance, can be resolved down to the level of individual cells and chloroplasts. Control of the instrument, as well as image capture, manipulation, analysis and presentation, are executed through an integrated computer application, developed specifically for the task. Possible applications for this instrument include detection of early and differential responses to environmental stimuli, including various types of stress. Images illustrating the instrument's capabilities are presented.     

A Cost-Effective Solution for the Reliable Determination of Cell Numbers of Microorganisms in Liquid Culture

The concentration of microorganisms in growth medium is an important parameter in microbiological research. One of the approaches to determine this parameter is based on the physical interaction of small particles with light that results in light scattering. Table-top spectrophotometers can be used to determine the scattering properties of a sample as a change in light transmission. However, a portable, reliable, and maintenance-free instrument that can be built from inexpensive parts could provide new research opportunities. In this report, we show how to build such an instrument. This instrument consists of a low power monochromatic light-emitting diode, a monolithic photodiode, and a microcontroller. We demonstrate that this instrument facilitates the precise determination of cell concentrations for the bacteria Escherichia coli and Pseudomonas aeruginosa as well as the cyanobacterium Synechocystis sp. PCC 6803 and the green alga Chlamydomonas reinhardtii.     

微机控制自动微容量测试仪的研制

采用光电传感信号、步进马达抽送液系统5、1系列单片微机控制和记忆系统,研制一种用于检测微容量变化的仪器,用于药理实验中对动物肢体容积变化进行测定。经10例小鼠实验证明,效果良好,该仪器为测定动物肢体容积变化提供了一种全新的先进方法。     

Flow-system measurement of cell impedance properties.

A flow-system technique has been developed that detects the high-frequency resistance and capacitance changes in a sensing orifice due to the passage of cells through the orifice. The resistance and capacitance changes are related to cell properties such as size, plasma membrane capacitance, and electrical resistivity of the cell interior. The relationship between measured impedances and cellular properties is discussed, and the prototype instrument for making such measurements is described. The instrument can simultaneously detect the dc Coulter volume and two ac parameters related to the complex ac impedance change. Some initial tests of the instrument using plastic microspheres and Chinese hamster ovary cells are described.     

High-pressure-temperature gradient instrument: use for determining the temperature and pressure limits of bacterial growth.

A pressurized temperature gradient instrument allowed a synoptic determination of the effects of temperature and pressure on the reproduction of bacteria. The instrument consisted of eight pressure vessels housed parallel to each other in an insulated aluminum block in which a linear temperature gradient was supported. For a given experiment, eight pressures between 1 and 1,100 bars were chosen; the linear temperature gradient was established over an interval within -20 to 100 degrees C. Pure cultures and natural populations were studied in liquid or solid medium either in short (ca. 2-cm) culture tubes or in long (76.2-cm) glass capillaries. In the case of a pure culture, experiments with the pressurized temperature gradient instrument determined values of temperature and pressure that bounded its growth. Feasibility experiments with mixed populations of bacteria from water samples from a shallow depth of the sea showed that the instrument may be useful in identifying the extent to which a natural population is adapted to the temperatures and pressures at the locale of origin of the sample. Additional conceived uses of the instrument included synoptic determinations of cell functions other than reproduction and of biochemical activities.