苹果常温保鲜技术

采用AF型气氛保鲜纸对苹果进行常温保鲜效果试验,并与其他保鲜方法进行了对比试验.该法具有简单易行、投资少、见效快等特点,可用于苹果常温贮藏保鲜.结果表明,用AF型气氛保鲜纸包裹苹果,可使苹果在常温下贮藏保鲜期稳定在140 d以上,失重率降低66.9%,皱皮率降低90.6%,腐烂率降低87.3%,硬度和可溶性固形物含量基本不变.     

The bactericidal activity of pulsed Nd-YAG laser radiation in vitro

Pulsed Nd-YAG laser irradiation of bacteria has been suggested as a possible means of treating contaminated intra-oral sites although relatively few studies have been conducted. In this investigation, the antimicrobial activity of a pulsed Nd-YAG laser was assessed in vitro for a range of oral bacteria using several pulse energies and exposure durations. Pure cultures of each organism were lased in saline suspensions followed by standard colony counting techniques for test and control samples. Microbial inhibition was found to be organism-dependent and varied with energy dose and pulse energy. For all nine test species 120-mJ laser pulses proved more efficient than 80-mJ pulses, with 99.9% kills compared with around 90% kills after exposure to 1800 pulses. These killing activity levels compare favourably with those achieved with other lasers in vitro.     

N-异丙基丙烯酰胺/N-羟甲基丙烯酰胺共聚物及其水凝胶的合成及其温敏性研究

通过自由基聚合合成了N-异丙基丙烯酰胺(NIPAm)与N-羟甲基丙烯酰胺(NHMPA)的共聚物及其水凝胶。研究发现，调节两单体的配比可得到不同的低临界溶液温度(LCST)值的共聚物及水凝胶。结果表明，NHMPA的加入不改变PNIPAm的温敏性，但可有效的调节其LCST值。     

Oxygenated and reoxygenated tumors show better local control in radiation therapy for cervical cancer

The presence of hypoxic cells is one of the major factors affecting resistance against radiation therapy. In the clinical setting, little information exists as to the relationship between intratumoral oxygen partial pressure (pO(2)) and outcome. This study involved 30 consecutive patients with cervical cancer, who were treated with a combination of external and high-dose rate intracavitary irradiation. The pO(2) was measured before radiation therapy and at 9 Gy, using a needle-type polarographic oxygen electrode. The mean intratumoral pO(2) before radiation therapy was 17.3 +/- 10.8 mm Hg. The 3-year local control rates of patients with pO(2)< or = 20 mm Hg and pO(2) > 20 mm Hg before radiation therapy were 52% and 100%, respectively, representing a significant difference (P= 0.035). At 9 Gy, mean intratumoral pO(2) was 23.6 +/- 9.1 mm Hg, a significant increase compared to the value before radiation therapy (P= 0.006). The 3-year local control rates of tumors with pO(2)< or = 20 mm Hg and pO(2) > 20 mm Hg at 9 Gy were 35% and 93%, respectively, representing a significant difference (P= 0.001). The significantly better local control for oxygenated tumors at 9 Gy as well as before radiation therapy indicated that the oxygen effect and reoxygenation by radiation played an important role in local control in radiation therapy for cervical cancer.     

常温与低温体外循环心脏直视手术对细胞因子及补体的影响

目的探讨常温及低温体外循环心脏直视手术对细胞因子及补体的影响。方法选择先天性和风湿性心脏病患者40例,随机分为常温组及低温组各20例,分别于术晨、体外循环结束时及术后1、4、7、14 d抽取患者静脉血标本,测定血浆TNF、IL-2、C3、C4值。结果两组术前各项检查指标无显著差异。(1)两组术后1~4 d的IL-2水平较术前显著下降,至术后7 d恢复正常。体外循环结束至术后4 d,低温组IL-2显著低于常温组。(2)体外循环结束时以及术后1、4、7 d,常温组TNF水平显著低于低温组。两组体外循环结束时及术后1、4 d均高于术前,常温组至术后7 d、低温组术后14 d恢复正常。(3)体外循环结束时及术后1、7 d,常温组C3水平高于低温组,术后4 d两组无差别;常温组及低温组于体外循环结束时、术后1、4 d均低于术前,至术后7 d常温组恢复正常,低温组至术后14 d恢复至术前水平。(4)两组体外循环结束时及术后1、4 d C4水平均低于术前。体外循环结束时、术后1 d,常温组C4水平高于低温组。结论常温体外循环心脏直视手术对细胞因子及补体的影响显著轻于低温组,因而对术后机体的恢复优于低温方法。     

常规染色体畸变分析法对AT细胞高辐射敏感性的研究

目的 研究毛细血管扩张性共济失调症(ataxia-telangiectasia,AT)患者皮肤的成纤维细胞系AT5BIVA(AT细胞)的高辐射敏感性。方法 以源于正常人皮肤的成纤维细胞系GM0639(GM细胞)为对照,用常规染色体畸变分析法,在AT细胞和GM细咆经60COγ射线0、1、2、3、4 Gy照射后,观察比较AT细胞和GM细胞之间染色体畸变率(CAF)的差异,并分别进行曲线拟合。结果 在0、1、2、3、4 Gy剂量下,AT细胞染色体畸变率明显高于GM细胞(P<0.05);AT和GM细胞染色体畸变率与剂量成正相关,均可拟合成剂量效应直线方程Y=a+bX,且AT细胞剂量效应直线回归方程斜率明显大于GM细胞(P<0.05)。结论 AT患者AT细胞的辐射敏感性显著高于GM细胞,具有高辐射敏感性。     

3种常用低温灭菌方法研究现状

阐述了环氧乙烷低温灭菌法、低温蒸汽甲醛灭菌法、过氧化氢等离子体灭菌法的灭菌机制、主要特点及应用范围。     

高温流化α-化在酿酒用大米预处理中的应用

作者研究了高温流化α-化工艺中大米淀粉晶粒、水分、绝干淀粉含量、糊化率、脂肪含量、总氮和可降解氮的变化。研究表明：高温流化α-化后淀粉晶粒消失，成松散片状，比表面积增大，有利于酶的作用；水分含量低于10％，可有效防止淀粉老化和微生物污染；高温流化处理后淀粉糊化率与蒸饭法持平，而脂肪与可降解氮含量均明显下降，为酿造淡爽型酿造酒和提高酿造酒非生物性稳定性创造了机会。该工艺尤其适合在我国以糙米为原料的酿造酒生产中推广应用。     

Late side-effects with cosmetic relevance following soft X-ray therapy of cutaneous neoplasias

Background Cosmetic changes are to be expected after radiotherapy for skin tumours. Objectives This study aimed to answer the questions: How frequent are cosmetic changes after soft X‐ray therapy? Do treatment parameters, tumour thickness, localization and size of the irradiated field have a major influence? Were patients irritated by the visual appearance of the irradiated field? Methods In total, 2474 examinations of 1149 irradiated fields were performed. Results Hypopigmentation was found in 64.7% of examinations more than 90 days after therapy, teleangiectases in 43.1%, erythema in 24.8%, and hyperpigmentation in 16.8%. The frequency of hypopigmentation, teleangiectases and hyperpigmentation increased with time from X‐ray exposure; more than 4 years after therapy hypopigmentation was diagnosed in 91.8% and teleangiectases in 82.2% of examinations. Total dose, the time–dose–fractionation factor (TDF), field size and dose per fraction were significantly related to the frequency of cosmetic changes. Incidence rates of cosmetic changes differed by less than 15% if different treatment conditions were compared: thicker vs. thinner tumours, larger vs. smaller fields, higher vs. lower total doses, doses per fraction, and TDF. Frequencies of hypopigmentation, teleangiectases, erythema and hyperpigmentation differed by more than 15% between some localizations on the head. Women reported irritation by the visual appearance of the irradiated field in 12.6% of 1116 interviews, and men in 4.4% of 1284 interviews. Conclusions Cosmetic changes after soft X‐ray therapy are relatively frequent. Treatment parameters, tumour thickness and field size have only a minor influence. Few patients, but more women than men, were irritated by the visual appearance of the irradiated field.