保存标本的时间和温度对血细胞参数的影响

目的 探讨同一批标本在不同的时问、不同的保存温度在同一部全自动血细胞分析仪对测定结果的影响。方法 采集20例本院健康体检者静脉血每位4m1分别注入2组EDTA-K2真空抗凝管中每管各2ml，其中一组在室温保存，另一组在4℃冰箱保存，用雅培CELL-DYN1700全自动血细胞分析仪，分别于采血后0、4、8、24h进行检测。结果 室温标本随着时间的延长对结果有影响，保存在4℃的标本在24h内完成除MPV外基本保持恒定。结论 血液标本采集后应尽量在4h内检测完毕，在4℃条件下保存，放置时间也不宜过长。     

保存标本的时间和温度对血细胞参数的影响

目的探讨同一批标本在不同的时间、不同的保存温度在同一部全自动血细胞分析仪对测定结果的影响.方法采集20例本院健康体检者静脉血每位4ml分别注入2组EDTA-K2真空抗凝管中每管各2ml,其中一组在室温保存,另一组在4℃冰箱保存,用雅培CELL-DYN1700全自动血细胞分析仪,分别于采血后0、4、8、24h进行检测.结果室温标本随着时间的延长对结果有影响,保存在4℃的标本在24h内完成除MPV外基本保持恒定.结论血液标本采集后应尽量在4h内检测完毕,在4℃条件下保存,放置时间也不宜过长.     

血液标本保存温度和时间对血小板系统检测指标的影响

本文探讨血液标本保存温度和时间对血小板系统检测指标的影响。     

标本温度、存储时间对肝功能生化检验结果的影响

目的 探讨标本温度、存储时间对肝功能生化检验结果的影响,为提高检验质量提供重要依据。方法 选取2018年10月~2019年2月我院检验科接受肝功能生化检验的200例健康者作为研究对象,均采集晨起空腹外周静脉血3.0 ml/管,共6管,比较常温及4℃环境,即刻及存储12 h检验,溶血及无溶血标本中肝功能生化指标水平。结果 无溶血标本的DBIL、AST、ALT、ALB水平高于溶血标本,ALP、TP、TBIL水平低于溶血标本,差异有统计学意义（P＜0.05）。常温与4℃保存标本的DBIL、TBIL、AST、ALT、ALB、ALP、TP水平比较,差异无统计学意义（P＞0.05）。即刻与存储12 h标本的DBIL、TBIL、AST、ALT、ALB、ALP、TP水平比较,差异无统计学意义（P＞0.05）。结论 血样标本保存温度、存储时间对肝功能生化检验结果影响甚微,但是溶血会对检验指标产生一定影响,因而在采血后特别注意标本状态变化,规避溶血现象,以保证检验结果的准确性。     

温度和时间对PT、APTT检测的影响

目的了解采血后放置时间，温度对阳、APTT测定结果的影响。方法将血浆分别置于4℃、20℃、37℃，严格按操作规程分别检测0、1、2、4、8h的阳、AfyIT值。结果在4℃8h、20℃8h、37℃2h，PT、APTT与0h测定结果有显著性差异。结论胛、APTT的测定应在4℃4h、20℃4h、37℃1h内完成。     

粉体粒径对碳酸化羟基磷灰石水泥固化时间和压缩强度的影响

目的　检测不同粉体粒径对碳酸化羟基磷灰石水泥 (carbonatedhydroxyapatitecement,CHC)的固化时间和压缩强度的影响 ,为其修复骨缺损提供理论基础。方法　采用研磨和超细粉体技术制备 4 0 0目、6 0 0目和超细粉体粒径的CHC干粉 ,检测不同粉体粒径对CHC固化时间和压缩强度变化。结果　超细CHC干粉平均粒径为3.10 9μm ,比表面积为 2 .2 88m2 /cm3 ,在 37℃、10 0 %湿度条件下CHC固化时间随粉体粒径减小而缩短 ,而固化后压缩强度随粉体粒径缩小而升高 ,超细粉体CHC初凝时间 3min ,终凝时间 8min ,最终固化后压缩强度 (5 1.0 4 2± 3.72 8)MPa。结论　超细CHC具有原位固化性能 ,固化时间合理 ,压缩强度高 ,比较符合临床使用的要求     

不同温度和时间对血常规参数检测结果的影响

目的探讨EDTA-K2抗凝静脉血在不同温度和时间对血常规参数检测结果的影响。方法运用XT-1800i全自动血细胞分析仪测定91份在不同温度下保存不同时间的血标本,其中31份血标本于4℃冷藏,并于0.5h、24h、48h、72h测定。30份血标本20℃保存,于0.5h、2h、4h、8h、24h测定;另30份血标本20℃保存,于24h、48h、72h再测定,各以0.5h测定结果为对照组,观察血常规参数检测结果变化。结果 20℃保存24h,WBC、RBC、Hb、MCH及WBC与对照组差异均无统计学意义(P>0.05),16种血常规参数差异均有统计学意义(P<0.05);20℃保存72h,WBC、RBC、Hb差异均有统计学意义(P<0.05),16种血常规参数从24h即有明显的变化,差别有统计学意义(P<0.05);4℃冷藏72h,WBC、RBC、MCH、Hb在72h内比较稳定,HCT、PLT及WBC分类在48h内比较稳定,14种血常规参数在24h有明显变化。结论血常规标本4℃冷藏,血细胞参数结果较稳定,但仍要考虑到个别参数的变化,以便于为临床提供更可信的数据。     

两种塑化材料对断层解剖标本制作效果的比较

目的:研究2种不同塑化材料制作的断层解剖标本的差异.方法:分别采用硅橡胶技术和聚酯共聚体技术制备人体断层标本,并进行比较.结果:硅橡胶技术所制备的标本不透明;聚酯共聚体技术制备的断层解剖标本半透明.硅橡胶材料制备的断层标本不适于研究组织纤维走向和筋膜结构,适用于标本防腐保存;聚酯共聚体材料制备的断层标本可以清晰地显示组织的纤维走向和筋膜结构,同时标本的厚度均匀,表面平滑,硬度较高.结论:聚酯共聚体材料制备的断层标本优于硅橡胶材料,此方法将会发展成为断层解剖学研究的常用技术.     

固化光源的种类对复合树脂充填材料固化收缩量的影响

本文研制开发了测量复合树脂固化收缩量的实验装置和检测方法。该装置采用激光测距传感器(测量精度为 1μm)和特制的材料固化腔 ,可以直接在光固化机照射的同时 ,测量复合树脂固化收缩的全过程。研究中采用 3种光固化机对 4种复合树脂材料进行 2种照射时间的固化收缩实验。经对实验结果分析发现 :复合树脂的固化收缩量的大小与固化光源的种类有关 ,用高能氙灯光源照射产生的固化收缩量最小 ;采用高能氙灯光源照射时固化收缩量小 ,并不完全是由于照射时间短 ,使复合树脂固化反应不充分所致 ,而是与光源本身的特性有关。     

放射免疫分析内皮素时温度和标记抗原作用时间改变的影响

观察了ＲＩＡ测定ＥＴ过程中1 2 5Ｉ-ＥＴ加入后各时间段的结果变化 ,并对 6个时间段进行了灵敏度、回收率、重复性试验材料和方法一、仪器和试剂 :(一 )仪器 :中国科大实业公司佳光仪器分公司ＧＣ - 12 0 0型γ计数器。(二 )试剂 :解放军总医院科技开发中心放免所提供的内皮素放免试剂盒。二、标本 :随机采集门诊病人静脉血 4 8例 (男 2 9,女 19) ,年龄 19～ 72岁。三、方法 :(一 )取静脉血 4ｍｌ加入含 6 0 μｌ 10 %ＥＤＴＡ -Ｎａ2 和 80 μｌ抑肽酶的试管混匀 ,4℃ ,30 0 0ｒｐｍ离心 10分钟分离血浆。(二 )取血浆 10 0 μｌ抗血清 10 …     

不同硬度鞋底对人体步行下肢运动学的分析

目的通过对穿着不同硬度鞋底的受试者开展步行时的运动学分析,评价不同硬度鞋底对人体下肢步行运动学参数的影响。方法受试者穿3种不同硬度鞋底的鞋,在跑台上以6 km/h的速度行走,利用Vicon红外摄像系统进行动作捕捉,以采集行走过程中脚后跟高度、脚尖高度、膝角度、踝角度等运动学参数,并分析实验结果。结果穿软底鞋的步态周期比其他鞋的步态周期增加,小腿前摆角度最小;穿中等硬底鞋大腿前摆角度最小、后摆角度最大;穿硬底鞋的大腿前摆角度最大、后摆角度最小;摆动期时间相对稳定。结论软底鞋更适合短时间慢速行走,中等硬底鞋对人体长时间步行的下肢运动学影响最小,硬底鞋适合短时间快速行走。     

Effects of pressure,cold and gloves on hand skin temperature and manual performance of divers

Cold water immersion and protective gloves are associated with decreased manual performance. Although neoprene gloves slow hand cooling, there is little information on whether they provide sufficient protection when diving in cold water. Nine divers wearing three-fingered neoprene gloves and dry suits were immersed in water at 25 and 4 degrees C, at depths of 0.4 msw (101 kPa altitude adjusted) and 40 msw (497 kPa) in a hyperbaric chamber. Skin temperatures were measured at the fingers, hand, forearm, chest and head. Grip strength, tactile sensitivity and manual dexterity were measured at three time intervals. There was an exponential decay in finger and back of hand skin temperatures with exposure time in 4 degrees C water. Finger and back of hand skin temperatures were lower at 40 msw than at 0.4 msw (P < 0.05). There was no effect of pressure or temperature on grip strength. Tactile sensitivity decreased linearly with finger skin temperature at both pressures. Manual dexterity was not affected by finger skin temperature at 0.4 msw, but decreased with fall in finger skin temperature at 40 msw. Results show that neoprene gloves do not provide adequate thermal protection in 4 degrees C water and that impairment of manual performance is dependent on the type of task, depth and exposure time.     

A catheter tactile sensor for measuring hardness of soft tissue: measurement in a silicone model and in anin vitro human prostate model

Tissue hardness is related to tissue composition, and this is often changed by disease. It is therefore of interest to measure the hardness in an objective and non-invasive way. A tactile sensor based on a vibrating piezoelectric ceramic element in a feedback loop is described. When the sensor touches an object it produces a frequency shift related to the hardness of the object. The aim of this study was to develop an in vitro hardness measurement method using a catheter type version of the sensor. The method was evaluated in an established silicone tissue model and on human prostate tissue in vitro. A linear relationship was found with a high degree of explanation (R2 = 0.98) between a cone penetration hardness standard (DIN ISO 2137) applied to the silicone model and the corresponding frequency shift. The results from measurements on a human prostate tissue sample, fixed with formalin, showed that the relative hardness measured with the tactile sensor correlated (R = -0.96, p < 0.001, N = 60) with the proposed hardness related to the histological composition of the prostate tissue. The results indicated that hardness of prostate tissue, and maybe hardness of human tissue in general, can be expressed according to the cone penetration standard and that the hardness can be measured with this tactile sensory system. These findings hold the promise of further development of a non-invasive tool for hardness measurement in a clinical situation.     

Effect of temperature and calcium on force-frequency relationships in mammalian ventricular myocardium

Summary The effects of temperature and calcium on force-frequency relationships in mammalian ventricular myocardium were studied in isolated papillary and ventricular muscle bundles. Tensions, velocities, and phase durations were determined from the isometric tension record and its first derivative. Decreasing bath temperature from 34–36°C to 27–31°C increased contractile tension and prolonged the phases of contraction in rat, guinea pig, and adult and fetal human tissues without altering the force-frequency relationship. Doubling extracellular [Ca⁺⁺] beyond the 2.7 mM control for human tissue increased contractile tension and shortened phase I, and made the force-frequency relationship less steep or biphasic. These results suggest that the negative force-frequency relationship in the failing human heart cannot be explained merely on the basis on unavailability of Ca⁺⁺ to the contractile proteins.This research was partially supported by Grant 1104 of the Research Foundation of the City University of New York.     

A catheter tactile sensor for measuring hardness of soft tissue: measurement in a silicone model and in anin vitro human prostate model

Tissue hardness is related to tissue composition, and this is often changed by disease. It is therefore of interest to measure the hardness in an objective and non-invasive way. A tactile sensor based on a vibrating piezoelectric ceramic element in a feedback loop is described. When the sensor touches an object it produces a frequency shift related to the hardness of the object. The aim of this study was to develop an in vitro hardness measurement method using a catheter type version of the sensor. The method was evaluated in an established silicone tissue model and on human prostate tissue in vitro. A linear relationship was found with a high degree of explanation (R²=0.98) between a cone penetration hardness standard (DIN ISO 2137) applied to the silicone model and the corresponding frequency shift. The results from measurements on a human prostate tissue sample, fixed with formalin, showed that the relative hardness measured with the tactile sensor correlated (R=−0.96, p<0.001, N=60) with the proposed hardness related to the histological composition of the prostate tissue. The results indicated that hardness of prostate tissue, and maybe hardness of human tissue in general, can be expressed according to the cone penetration standard and that the hardness can be measured with this tactile sensory system. These findings hold the promise of further development of a non-invasive tool for hardness measurement in a clinical situation.     

Quantitative analysis of the insulating effect of silicone oil on the electroretinogram

A model of the ERG focusing on the insulation effect of silicone oil replacing the vitreous was used to quantify the ERG. The electrical properties of the structures of the eye, the frequency content of the ERG and the percentage of the silicone oil along with the remaining vitreous were incorporated in the model. The result was that it was not until at least 50 per cent of the vitreous was replaced with silicone oil that there was a small reduction in the ERG. As more silicone oil was put into the vitreous cavity the ERG became smaller. If the replacement were large leaving a layer of vitreous 0·24 mm thick, little ERG would be measured even if the retina were functional.     

Effect of muscle temperature on leg extension force and short-term power output in humans

Summary The effect of changing muscle temperature on performance of short term dynamic exercise in man was studied. Four subjects performed 20 s maximal sprint efforts at a constant pedalling rate of 95 crank rev · min⁻¹ on an isokinetic cycle ergometer under four temperature conditions: from rest at room temperature; and following 45 min of leg immersion in water baths at 44; 18; and 12‡ C. Muscle temperature (Tm) at 3 cm depth was respectively 36.6, 39.3, 31.9 and 29.0‡ C. After warming the legs in a 44‡ C water bath there was an increase of ∼11% in maximal peak force and power (PP_max) compared with normal rest while cooling the legs in 18 and 12‡ C water baths resulted in reductions of ∼12% and 21% respectively. Associated with an increased maximal peak power at higher Tm was an increased rate of fatigue. Two subjects performed isokinetic cycling at three different pedalling rates (54, 95 and 140 rev · min⁻¹) demonstrating that the magnitude of the temperature effect was velocity dependent: At the slowest pedalling rate the effect of warming the muscle was to increase PP_max by ∼2% per ‡ C but at the highest speed this increased to ∼10% per ‡ C.     

Effects of temperature and incubation time on production of ochratoxin A by black aspergilli

The effects of temperature (5-45 degrees C) on the growth and production of ochratoxin A (OTA) by eighteen strains of Aspergillus section Nigri, cultured on Czapek yeast autolysate agar (CYA) and on yeast extract sucrose agar (YES), were studied for an incubation period of 30 days. Isolates were selected to include different sources and different reported abilities to produce OTA. Temperature ranges for OTA production were more restrictive than those for growth and each strain tested differed in its optimum conditions for OTA production. Aspergillus niger aggregate strains achieved maximum OTA levels in YES medium mainly at 20-25 degrees C. The A. carbonarius strains produced the highest OTA levels in CYA medium at 15 or 20 degrees C. Significant amounts of OTA were produced after only five days of incubation. Due to their ability to produce OTA at a wide range of temperatures, OTA can be continuously produced in the field. This fact has to be taken into account in commodities such as grapes, raisins and wine, where A. carbonarius and members of the A. niger aggregate are considered to be the main sources of the OTA contamination.     

医用硅橡胶的生物相容性缺点及现代改良

硅橡胶具有性能稳定、易于塑形、产品效益可观的优点,已广泛应用于生物医学工程领域和医疗卫生行业.尽管如此,硅橡胶在生物医学领域中的应用仍然受到其自身缺陷的挑战.表面疏水性、自身影像相容性欠佳、长期植入体内后发生钙化乃是医用硅橡胶制品在生物相容性方面亟待克服的缺点.近几年来国内外专家针对以上缺点进行了诸多改良研究,热点主要集中于硅橡胶的表面湿润性增加、X-线阻射功能增强、防钙化预处理等方面.取得了阶段性成果,但尚未使医用硅橡胶的生物相容性达到理想的境界.     

Influence of curing agent on fibrosis around silicone implants

Severe capsular contracture around silicone expander breast implants leading to pain and failure is a major clinical problem. Even though earlier studies have implicated the immunogenicity of silicone, the role of physical and chemical properties of the silicone material in excessive collagen deposition and fibrosis has been less addressed. The present study investigates whether there is any correlation between the type of curing systems i.e. addition and free radical curing and the fibrosis around silicone elastomer. The experiment carried out uses commercially available silicone ventriculo-peritoneal shunt material elastomer cured by platinum and the results are compared with results obtained in a similar study carried out by the authors using commercially available silicone tissue expander material cured by peroxide. Ultra-high molecular weight poly-ethylene (UHMWPE), the standard reference for biocompatibility evaluation, was used as the control material. The materials were implanted in rat skeletal muscle for 30 and 90?days. Inflammatory cells, myofibroblasts, cytokines, and collagen deposition at the material–tissue interface were identified by haematoxylin–eosin and Masson’s Trichrome stains and semi-quantitated based on immunohistochemical studies. Results indicate that even though the cellular response in the initial phase of wound healing was similar in both platinum and peroxide-cured materials, the collagen deposition in the proliferative phase was more around peroxide-cured material in comparison to the platinum-cured silicone elastomer. There is a need to look into the molecular mechanisms of this interaction and the possibility of using curing systems other than free radical peroxide in the manufacture of silicone elastomer expanders for breast prosthesis.