加热诱导肝癌细胞系HepA凋亡的研究

用细胞培养结合流式细胞仪检测 ,观察加热不同温度、不同作用时间对肝癌细胞系 Hep A的细胞凋亡的影响。结果发现 4 4℃时处理 1h和 2 h细胞凋亡最明显 ,经方差分析有显著意义 (P<0 .0 5 ) ,更高的温度和更长的作用时间都不能使凋亡率上升。这一结果说明 ,加热处理能诱导肿瘤细胞凋亡 ,但对于不同的肿瘤细胞而言 ,可能存在不同的热疗最佳条件 ,因此有必要分别研究不同肿瘤细胞对热疗的敏感程度     

Electric heating pad burns

Patients with sensory deficits are especially prone to heating pad burns. Two cases are reported of patients with anesthetic skin who received partial and full-thickness burns of their feet from an electric heating pad. These burn injuries could have been prevented if the patients understood the potential hazard of heating pads.     

The potential of mild testicular heating as a safe, effective and reversible contraceptive method for men

A preliminary assessment of the contraceptive efficacy of a daily mild increase (1–2°c) in testicular temperature during waking hours is reported in nine couples using two techniques of non-surgical fixation of the testes close to the inguinal canal. With technique 1, immobilization was achieved by passing the penis and the empty scrotum through a hole made in close-fitting underwear; there was one pregnancy, hm a man who stopped the heating after 7 weeks, for 42 cycles of exposure in three couples. With technique 2, immobilization was achieved by adding a ring of soft material surrounding the hole in the underwear; there was no pregnancy for 117 cycles of exposure in six couples. Reversibility and safety were assessed. These preliminary results suggest that a daily mild increase in testicular temperature could be a potential contraceptive method for men.     

Evaluation of the genetic toxicity of middle distillate fuels

Petroleum middle distillate (PMD) fuels are mixtures of hydrocarbons that distill between ～ 170-370°C. Commercial products that fall into this category include kerosine, diesel fuel, jet fuel, and home heating oil. These products contain both saturated (paraffins and cycloparaffins) and aromatic species, but because of the boiling range normally contain very small amounts of the 3-6 ring polycyclic aromatic hydrocarbon (PAH) constituents, which are considered to be carcinogenic. Nevertheless, there is evidence of weak tumorigenic activity when these materials are repeatedly applied to mouse skin. In the current studies representative products were tested in two commonly used, short-term assays for genetic toxicity, the Salmonella/mammalian microsome mutagenicity assay and the mouse bone marrow micronucleus test. All samples were inactive in the micronucleus assay, and three were clearly inactive in the Salmonella test. Of the remaining two, one was marginally active in the Salmonella assay, and one was equivocal. The marginally active sample contained detectable levels of PAH due to the use of catalytically cracked materials as blending stocks. The results indicated that PMDs that do not contain cracked material were not mutagenic. Thus they may produce tumors via nongenotoxic processes. Those products that do contain cracked stocks may have sufficient PAH to be mutagenic in the Salmonella assay, and in those cases the PAH might also contribute to tumor formation. © 1994 Wiley-Liss, Inc.     

An investigation into the combined effects of X-irradiation and microwave heating on pig skin

An investigation has been made of the effects of microwave heating in enhancing the radiation response of pig skin following exposure to X-rays. Areas on the flanks of pigs were treated with X-rays alone or with X-rays followed by heating for 90 minutes at either 42°C or 44°C. Treatment was given as either a single dose or as three fractions over six days. Microwave heating was produced by two types of direct contact applicator operating at a frequency of 2450 MHz. Skin temperature was monitored with a liquid crystal thermometer and with thermocouples. The early skin reaction was scored quantitatively up to 16 weeks following treatment. The thermal enhancement ratios (TER's) measured were close to unity for all treatments. For single dose treatments and heating at 42°C for 90 minutes, the TERwas 1.05. For the three fraction treatments, the TER was found to be 1.1 when heat treatment was either 42°C/90 minutes or 44°C/90 minutes. Such TER values are in general agreement with those recommended by the Radiation Therapy Oncology Group (RTOG) in North America.     

大鼠睾丸局部热作用对生精细胞凋亡的影响

目的 :研究大鼠睾丸局部受热后生精细胞凋亡的情况。　方法 :70只雄性SD大鼠随机分为热处理组 ( 43℃ )和对照组 ( 2 2℃ ) ,分别按睾丸局部处理后 12h、1d、3d、6d、10d、5 0d和 80d分成 7个亚组。应用电镜、流式细胞术和原位末端标记法 (TUNEL) ,检测各亚组大鼠睾丸生精细胞凋亡情况。　结果 :电镜显示热处理各组均出现生精细胞凋亡表现 ;流式细胞术检测发现热处理各组亚单倍体细胞百分率明显升高 (P <0 .0 1) ;TUNEL法显示热处理各组生精细胞凋亡率明显高于对照组 (P <0 .0 1) ,各类生精细胞对热的敏感性不同。　结论 :大鼠睾丸局部受热后生精细胞凋亡增加 ,初级精母细胞受热后最敏感 ,其次为精子细胞和精子 ,并且精原细胞凋亡在受热后一个长时期内均有增加     

Changes in serotonin in rat brain during slow-wave sleep and paradoxical sleep: application of the microwave fixation method to sleep research

Neural responses to several chemicals of the pit organs and terminal buds on the facial skin of the carp were compared electrophysiologically. Nerve inpulses from the pit organs were larger than those from the terminal buds. The pit organs were more sensitive to salts and especially acids than the terminal buds. The former did not respond to sucrose, silk worm pupa extract, betaine and amino acids except acidic ones. The latter, however, responded well to them.     

指数程序升温药物稳定性试验

介绍了一种新的程序升温(指数程序升温)药物稳定性预测加速试验方法及计算方法。在这一新的程序升温方法中,温度每升高10℃,升温速率将增大2～4倍:dT/dt=a^(T-T₀)/10·(dT/dt)₀,使药物在高温和低温范围内的降解程度尽可能一致,提高了试验准确度。采用单因素优选法和数值积分法处理试验数据,避免了任何近似处理,使计算结果准确可靠。与线性升温、倒数升温和对数升温加速试验进行了对比,结果表明,指数程序升温法的准确性优于其它3种升温法。     

炭黑／结晶性含氟树脂合金在自控温加热电缆中应用

选择了结晶性含氟树脂添加改性剂为树脂基体，与炭黑制居复合导电体系。通过这个对体系不同条件下ＰＴＣ特性的研究，对其配方与加工工艺进行优化。并利用扫描电镜，Ｘ射线衍射，ＤＳＣ等分析测试手段，对体系的各种开矿结构进行了研究，阐明了该导电复合体系的形态结构与性能的关系。