新疆某铀矿山周边食品放射性核素监测与分析

目的 了解新疆某铀矿山周边食品的放射性水平,补充新疆食品放射性核素基线数据库,分析放射性核素含量,估算居民由膳食摄入所致内照射剂量。方法 2018—2020年采集食品样品6类71份,用高纯锗γ能谱仪对感兴趣核素²³⁸U、²³²Th、²²⁶Ra、⁴⁰K和¹³⁷Cs的比活度进行测量、统计、分析,并对其所致居民年有效剂量进行估算。结果 2018—2020年食品样品中均未检出核素²³⁸U,其余放射性核素的平均活度浓度和检出率分别为²³²Th：0.428 ±0.038 Bq/kg（18.3%）、²²⁶Ra：0.477 ±0.063 Bq/kg（38%）、⁴⁰K：162 ±7 Bq/kg（100%）、¹³⁷Cs：0.071 ±0.011 Bq/kg（29.6%）,居民因食品放射性核素所致年有效剂量约为0.198 mSv。结论 新疆某含铀矿山周边食品的放射性水平在国家标准限值以内,居民因膳食所致年平均有效剂量与(UNSCEAR)2000年报告相符合,食品样品中检出的人工放射性核素¹³⁷Cs的含量不会对居民健康造成危害。     

个人剂量监测中异常结果的调查与分析

目的 对2014—2017年本实验室个人剂量监测过程中出现的异常结果进行调查与原因分析。方法 放射工作人员佩戴热释光个人剂量计监测个人剂量当量H_P(10),对测量结果超过调查水平的进行统计分析。结果 2014—2017年,本实验室共出现40个单位69人次个人剂量监测结果异常,其中从事诊断放射学的占83%;剂量结果在1.25～5.00 mSv占54%;导致剂量结果异常的主要原因有剂量计佩戴不规范（67%）、原因不明（20%）、工作量增加（10%）和设备维修（占3.0%）等。结论 加强放射工作单位对放射工作人员的管理及放射防护培训,提高个人防护意识。     

高传能线密度辐射对人眼晶状体的危害

眼晶状体是人体对辐射最敏感的组织之一,电离辐射的生物效应因其传能线密度（linear energy transfer, LET）的不同而不同,同等吸收剂量条件下,高LET辐射生物效应比低LET辐射更强,尽管目前辐射对眼晶状体的影响这一领域已经有了较多研究,但对于高LET对眼晶状体的影响知之甚少。本文简述人眼晶状体剂量限值的历史变化情况,综述各种高LET粒子的生物学实验,调查高LET辐射眼晶状体的流行病学,简要分析高原白内障高患病率的原因,并初步讨论未来研究高LET需要考虑的因素,旨在为国内今后开展高LET辐射对人眼晶状体的研究提供有价值的信息。     

清肝袋泡剂治疗高催乳素血症临床与实验研究

目的：进一步观察清肝袋泡剂对高催乳素血症（ＨＰＲＬ）患者的临床疗效,探讨其作用机制。方法：随机将患者分为治疗组１２０例（清肝袋泡剂）,对照组４０例（溴隐亭）。观察血中催乳素（ＰＲＬ）和相关激素水平及症状变化情况,进行疗效对比。同时通过动物实验对内分泌水平及卵巢、子宫、乳腺的组织形态变化进行同步观察。结果：清肝袋泡剂可显著降低患者血清ＰＲＬ水平,对相关激素有良性调节作用,临床疗效良好,与对照组比较无显著性差异（Ｐ＞０．０５）;动物实验证明能促进卵泡发育,使子宫内膜出现各动情周期的变化,抑制乳腺腺体增生。结论：清肝袋泡剂可有效治疗ＨＰＲＬ。     

二硫化碳作业女工早期胚胎损伤的剂量反应关系

目的 探讨女工二硫化碳（ＣＳ２）接触水平与胚胎早期发育障碍之间的剂量－反应关系。方法 前瞻观察生育女工妊娠所需的月 经周期数;收集每个月经周期胚胎植入期尿样,检测绒毛膜促性腺激素含量;监测女工作业地点ＣＳ２浓度。结果 ２５７名接触组经临床确诊妊娠的女工,各月经周期妊娠机率低于３６６名对照组女工,时间妊娠率随女工ＣＳ２接触水平（ＣＳ２接触浓度以ＣＳ２接触工龄）升高而降低：妊娠率＝０．７０３３－０．０     

Erbium filtration: a cost-effective, dose-reducing filter which maintains abdominal image quality

The current study investigated the effect of erbium filtration on an anteroposterior abdominal image. The radiation dose reductions achieveable and the costeffectiveness of this filter were also evaluated. An assessment of the radiation dose delivered employing either the standard total filtration (3 mm Al equivalent) or 0.1 mm of erbium filtration added to the standard filtration was undertaken on 21 patients. Image quality was assessed using the Commission of European Communities (CEC) criteria. Significant reductions of 64.6 % in entrance surface (p = 0.0001) and 23.4 % in effective dose (p = 0.0099) were recorded with erbium filtration. Image quality was maintained and the cost per manSievert saved was ￡ 128. More widespread use of this dose reducing filter is advocated. Received: 7 August 1998; Revised: 19 February 1999; Accepted: 19 April 1999     

槲皮素对培养人视网膜色素上皮细胞增生及DNA合成的影响

目的研究槲皮素(quercetin, QUE)对培养人视网膜色素上皮(retinal pigment epithelium, RPE)细胞增生和DNA合成以及对表皮生长因子(epidermal growth factor, EGF)促RPE细胞增生和DNA合成作用的影响。方法用细胞计数和3H-胸腺嘧啶核苷(3H-thymidine, 3H-TdR)掺入方法,观察不同浓度(200、100、50、1μmol/L)的QUE和最大浓度的QUE(200μmol/L)在不同作用时间（24-168小时）,分别单独或与EGF共同作用时,对RPE细胞增生及DNA合成的影响,排除着色的死细胞,用活细胞计数法判断药物的细胞毒性作用。结果QUE 200μmol/L具有最强的抑制效应,48小时时抑制效应已明显出现,96小时时抑制达到高峰。与QUE单独作用相比,QUE对EGF的促RPE细胞增生效应能产生更强的抑制。QUE无细胞毒性作用,各实验组细胞活力均在85.00%以上。结论QUE以剂量依赖和时间依赖的方式抑制RPE细胞的增生,尤其是由EGF刺激的增生,并且对培养的RPE细胞无细胞毒作用。(中华眼底病杂志,1999,15:27-29)     

Buprenorphine and naloxone combinations: the effects of three dose ratios in morphine-stabilized, opiate-dependent volunteers

Sublingual buprenorphine is a promising new treatment for opiate dependence, but its opioid agonist effects pose a risk for parenteral abuse. A formulation combining buprenorphine with the opiate antagonist naloxone could discourage such abuse. The effects of three intravenous (IV) buprenorphine and naloxone combinations on agonist effects and withdrawal signs and symptoms were examined in 12 opiate-dependent subjects. Following stabilization on a daily dose of 60 mg morphine intramuscularly, subjects were challenged with IV doses of buprenorphine alone (2 mg) or in combination with naloxone in ratios of 2:1, 4:1, and 8:1 (1, 0.5, or 0.25 mg naloxone), morphine alone (15 mg) or placebo. Buprenorphine alone did not precipitate withdrawal and had agonist effects similar to morphine. A naloxone dose-dependent increase in opiate withdrawal signs and symptoms and a decrease in opioid agonist effects occurred after all drug combinations. Buprenorphine with naloxone in ratios of 2:1 and 4:1 produced moderate to high increases in global opiate withdrawal, bad drug effect, and sickness. These dose ratios also decreased the pleasurable effects and estimated street value of buprenorphine, thereby suggesting a low abuse liability. The dose ratio of 8:1 produced only mild withdrawal symptoms. Dose combinations at 2:1 and 4:1 ratios may be useful in treating opiate dependence. Received: 9 February 1998/Final version: 8 May 1998     

Flexure dose: the low-dose limit of effective fractionation

Total radiation dose often can be increased without subsequent increases in the severity of tissue injury by using reduced doses per fraction. The flexure dose, df, is defined as the largest fractional dose for which further fractionation produces no significant change in the total dose required to reach a specified effect level. Thus, df is clinically relevant in that it represents the limit of effective dose fractionation. For those tissues in which injury reflects depletion of a critical proportion of target cells, the flexure dose is a measure of the extent of the initial, nearly linear portion of the dose-survival curve. More generally, the flexure dose is a measure of the extent of the initial, nearly linear portion of a dose-response curve in organized tissue, whatever its relationship to clonogenic target cells might be. Several quantitative expressions for df are derived. The characteristic common to these is that each defines the flexure dose as a multiple of the ratio alpha/beta of the parameters of the linear-quadratic model of cell survival or dose response, where the multiple is a measure of experimental or statistical resolution. These multiples tend to fall within a limited range, thereby defining the "region of flexure" via the inequality 0.05 (alpha/beta) less than or equal to df less than or equal to 0.15 (alpha/beta). Estimates of the region of flexure are presented for a variety of normal and neoplastic tissues.