赤峰市饮用水中的总放射性水平调查

目的 了解赤峰市饮用水中的总放射性水平,估算由饮用水摄入放射性核素所致辐射年均有效剂量。方法 在赤峰市12个旗县区布点采集水样,用低本底α、β放射性测量仪和高纯锗γ能谱仪进行测量。结果 本次调查的赤峰市饮用水中的总α放射性水平为0.016~1.230 Bq/L,总β放射性水平为0.039~0.878 Bq/L。居民通过饮用自来水摄入总α放射性所致辐射年均有效剂量为0.071 mSv/年。结论 本次调查的赤峰市饮用水中的总α总β平均值低于世界卫生组织(WHO)的指导值,居民饮用自来水所致辐射年均有效剂量在安全水平之下。     

内蒙古地区饮用水中总α及天然放射性核素的活度浓度调查研究

目的 了解内蒙古地区饮用水中的放射性水平,研究分析内蒙古个别地区饮用水中总α放射性水平较高的原因。方法 根据已筛查结果再次采集内蒙古地区部分城镇总α放射性水平较高的水样,用低本底α、β放射性测量仪测量、微量铀分析仪和电感耦合等离子体质谱仪分析其放射性指标异常的原因,估算居民饮水摄入放射性所致待积有效剂量。结果 自来水样品总α放射性活度0.508~1.00 8 Bq/L,出厂水总α放射性活度0.507~1.965 Bq/L。激光荧光法测量自来水铀浓度范围为3.41~35.71 μg/L,出厂水铀浓度范围为3.62~32.61 μg/L。电感耦合等离子体质谱仪法测量自来水中的²³⁸U浓度范围5.83~34.36 μg/L、²³²Th浓度范围0.002~0.359 μg/L;出厂水中的²³⁸U浓度范围5.62~29.41 μg/L、²³²Th浓度范围0.003~0.327 μg/L。结论 通过对内蒙古部分地区饮用水样的复测分析研究发现,水样中总α放射性水平较高的原因源于铀,铀含量的偏高导致总α值偏高。     

巴彦乌拉铀矿周围饮用井水中总放射性水平调查

目的 调查巴彦乌拉铀矿周围饮用井水中总放射性水平。方法 采集2020年巴彦乌拉铀矿周围枯水期和丰水期饮用井水174份,以及居民家中经过滤后的饮用井水5份。分析枯水期和丰水期总α和总β放射性水平是否存在差异,总放射性水平与距离铀矿中心不同位置的关系,并对居民家中过滤后的饮用井水进行放射性水平调查。采用低本底α、β放射性测量仪测量分析其放射性水平。结果 巴彦乌拉铀矿周围饮用井水中,枯水期总α范围为0.024~ 2.468 Bq/L, 平均为(0.605±0.507)Bq/L,总β变化范围为0.125~1.395 Bq/L,平均为(0.420±0.235)Bq/L。丰水期总α变化范围为0.049~2.988 Bq/L,平均为(0.825±0.605)Bq/L,总β变化范围为0.059~1.623 Bq/L,平均为(0.506±0.265)Bq/L。距离铀矿中心位置水样的总放射性水平均值关系为10 km>30 km>20 km。结论 巴彦乌拉铀矿周围饮用井水中的放射性活度偏高,丰水期水样中总α、总β放射性水平均大于枯水期,放射性水平较未开采前未见升高。     

秦山核电站二期扩建工程运行后周围饮用水总放射性水平调查

目的 调查分析秦山核电站二期扩建工程正式投入运行后周围饮用水中的总放射性水平及变化趋势。方法 2010—2022年,每年分别在丰水期(5月)和枯水期(10月)采集秦山核电站周围30 km内的水源水、出厂水和末梢水,测定分析饮用水中总α、总β放射性活度浓度,并与国内不同核电站周围饮用水、无核电站地区周围饮用水总放射性水平进行比较。结果 水源水总α、总β放射性活度浓度均值分别为(0.021±0.019)和(0.204±0.058)Bq/L,出厂水总α、总β放射性活度浓度均值分别为(0.010±0.005)和(0.185±0.056)Bq/L,末梢水总α、总β放射性活度浓度均值分别为(0.012±0.007)和(0.170±0.058)Bq/L,均低于《生活饮用水卫生标准》规定的限值,3类水体在丰水期和枯水期监测结果差异均无统计学意义(P>0.05),与国内不同核电站周围饮用水以及无核电站地区周围饮用水总放射性水平接近。结论 二期扩建工程正式投入运行后,秦山核电站周围饮用水中总α、总β放射性水平处于本底水平且趋势平稳,低于国家标准指导水平。     

三门核电站运行前后生活饮用水中总放射性和食品中90Sr水平调查

目的 调查分析三门核电站运行前后,三门核电站周围生活饮用水中总放射性及食品中⁹⁰Sr的放射性水平。方法 在2012-2019年,选取三门核电站周围7个生活饮用水监测点,分别采集丰水期和枯水期的水源水、出厂水、末梢水,测定分析水中总α、总β放射性水平;结合当地居民饮食习惯,采集三门当地出产的谷类、青菜、淡水鱼、海鱼等4种食品,测定分析其中的⁹⁰Sr放射性水平。结果 三门核电站运行前,核电站周围生活饮用水中总α、总β放射性活度浓度范围为0.001~0.063 Bq/L和0.019~0.210 Bq/L;运行后,总α、总β放射性活度浓度范围为0.001~0.084 Bq/L、0.025~0.079 Bq/L,均低于《生活饮用水卫生标准》（GB 5749-2006）国家标准指导值。丰水期和枯水期的水源水、出厂水、末梢水中总α、总β放射性水平未见明显变化。运行前,4类食品⁹⁰Sr放射性活度浓度范围为0.037~1.216 Bq/kg,运行后为0.049~0.692 Bq/kg,均低于《食品中放射性物质限制浓度标准》（GB 14882-94）指导值。结论 三门核电站运行前后,生活饮用水中总α、总β及食品中⁹⁰Sr放射性水平平稳,低于国家标准限值。     

广东省饮用水源水总α和总β放射性水平调查与分析

目的 调查广东省饮用水源水中的总α、总β放射性本底水平,建立水源水放射性水平基线值,为评估核技术应用或人类活动可能所致的饮用水潜在放射风险评估提供基础数据。方法 在全省191个在用水源,分别采集丰水期、枯水期各1次,依照GB/T 5750.13-2006《生活饮用水标准监测方法-放射性指标》要求进行采样、检测分析。按照GB 5749-2006《生活饮用水标准》评价总α、总β放射性水平。结果 丰水期、枯水期共采样382个。用于总α、总β分析的样品为377个,其中丰水期189个,枯水期188个,丰水期与枯水期一一配对样品186个。所有水源水,枯水期总α放射性水平为（0.034±0.060）Bq/L （0.008~0.582 2 Bq/L）、总β放射性水平为（0.108±0.091）Bq/L （0.014~0.637 Bq/L）,丰水期总α放射性水平为（0.045±0.064）Bq/L （0.008~0.402 Bq/L）、总β放射性水平为（0.125±0.128）Bq/L （0.014~0.848 Bq/L）。除汕尾地区响水水库枯水期有1个样品的总α放射性水平（0.582 Bq/L）超过国家饮用水放射性标准指导值外,其他样品总α、总β放射性水平皆远低于国家饮用水放射性标准指导值,丰水期总α放射性水平高于枯水期（t=2.619,P<0.05）。不同水系丰水期、枯水期总α（F_丰水期=1.819,F_枯水期=1.985,P<0.05）、总β（F_丰水期=2.709, F_枯水期=8.461,P<0.05）放射性水平差异均有统计学意义,以粤西诸河为最高。地下水在丰水期的总α、总β放射性水平均高于河流水和湖库水,河流水总α、总β放射性水平高于湖库水,差异均有统计学意义（F_总α=39.323, F_总β=25.911,P<0.05）;枯水期的总α、总β放射性水平高于河流水和湖库水,差异均有统计学意义（F_总α=11.520,F_总β=28.435,P<0.05）;总体上呈现为地下水最高,其次是河流水,最低是湖库水。结论 掌握了广东省全省饮用水源水放射性本底水平分布,低于我国规定的饮用水指导值。粤西诸河水源水放射性水平明显高于其他水系,河流水放射性水平也明显高于湖库水。     

乌鲁木齐市食品中总α和总β放射性水平初步调查与分析

目的 通过对乌鲁木齐市部分食品中总α和总β放射性的调查,掌握当地部分食品总α和总β放射性基线资料。方法 采集谷类、蔬菜、水果、坚果、肉类和奶类等6类食品,将可食用部分进行样品前处理,采用MPC 9604低本底α、β测量仪,测定食品中总α和总β放射性。结果谷类、蔬菜、水果、坚果、肉类和奶类等的总α和总β放射性分别为0.88~10.80和22.20~148.67、1.17~24.24和21.41~318.84、1.44~4.89和43.90~112.67、17.49~43.72和287.81~747.40、3.04~19.77和41.55~164.51、2.07~2.94和44.07~59.02 Bq/kg。结论 乌鲁木齐市部分食品中天然总放射性与其他省市比较存在差异,推测为地域差异。为进一步掌握乌鲁木齐市食品中天然放射性的基线值,需要扩大样本量和种类继续进行动态的监测。     

2018年秦山核电站周边饮用水中总α和总β放射性水平的监测与分析

目的 了解秦山核电站周边的饮用水中总α、总β放射性本底水平。方法 根据国家卫生健康委员会方案,2018年在海盐县内距秦山核电站周围30 km范围内的11个监测点,在上半年和下半年分别采集水源水、出厂水和管网末梢水各1次,依据GB/T 5750.13-2006《生活饮用水标准检验方法放射性指标》进行采样、检测分析。检测的饮用水中总α、总β放射性水平按GB 5749-2006《生活饮用水卫生标准》进行评价,并比较2018年与2016-2017年末梢水中总α、总β放射性水平。结果 11个采样点分别在2018年4月和9月共采得水样22份,测得饮用水蒸干后的残渣率与不同类型水体有关,水源水残渣率稍高,达0.033 7%。不同类型水体中总α放射性水平范围为0.008~0.040 Bq/L,平均值为（0.015±0.009）Bq/L,总β放射性水平范围为0.014~0.320 Bq/L,平均值为（0.188±0.068）Bq/L。水源水和出厂水总α放射性水平比较,差异具有统计学意义（Z=-2.286,P<0.05）;残渣量与总α、总β放射性水平无线性关系,差异均无统计学意义（P>0.05）。2018年末梢水与2016-2017年比较,总α、总β放射性水平比较差异有统计学意义（Z=-2.976、-2.031,P<0.05）,2017年末梢水与2016年比较,总α、总β放射性水平比较差异有统计学意义（Z=-2.042、-3.214,P<0.05）,2018年末梢水与2017年比较,总α、总β放射性水平比较差异有统计学意义（Z=-20.112、-2.511,P<0.05）,但均符合标准要求。结论 核电站运行未对其周围饮用水的放射性水平产生影响,秦山核电站周围饮用水是安全的。     

内蒙古自治区食品和水中天然放射性核素水平及其所致居民内剂量评价的研究

本文报道了1983年至1986年内蒙古地区27种食品和水(自来水、井水、河、湖水)中天然放射性核素U、Th、²²⁶Ra、⁴⁰K的放射性水平。U、Th、²²⁶Ra所致城、乡牧居民年摄入量分别是:166Bq、147Bq、145Bq;致居民年有效剂量当量分别是:27μSv、26μSv、23μSv。     

红沿河核电站运行前周边地区放射性水平及所致居民剂量

目的 调查辽宁红沿河核电站运行前周边地区食品和饮用水以及环境放射性本底水平。方法 监测核电站周边30 km范围内12个采样点的食品、饮用水、土壤中γ核素浓度和2个采样点的沉降灰、气溶胶放射性水平以及地表天然γ辐射水平,并估算当地居民由膳食摄入所致内照射剂量。结果 当地食品中的放射性核素主要为天然核素²³⁸U、²²⁶Ra、²³²Th、⁴⁰K以及人工核素¹³⁷Cs,其中食品中 ¹³⁷Cs平均活度水平（0.029±0.043）Bq/kg。饮用水中总α放射性水平（0.07±0.06）Bq/L,总β放射性水平为（0.32±0.35）Bq/L,沉降灰总β放射性水平（0.40±0.14）Bq·m^-2·d^-1,气溶胶样品中未发现人工核素,周边地区土壤中¹³⁷Cs平均活度为（2.16 ± 1.37）Bq/kg。结论 核电站周边地区采集的食品中除微量¹³⁷Cs外,未见其他人工γ核素,食品和饮用水中放射性核素水平均低于国家标准限值,沉降灰及气溶胶放射性水平在正常本底范围,居民由食入人工核素¹³⁷Cs所致年有效剂量为0.18 μSv/年。     

Glutamine supplementation in vitro and in vivo,in exercise and in immunodepression

In situations of stress, such as clinical trauma, starvation or prolonged, strenuous exercise, the concentration of glutamine in the blood is decreased, often substantially. In endurance athletes this decrease occurs concomitantly with relatively transient immunodepression. Glutamine is used as a fuel by some cells of the immune system. Provision of glutamine or a glutamine precursor, such as branched chain amino acids, has been seen to have a beneficial effect on gut function, on morbidity and mortality, and on some aspects of immune cell function in clinical studies. It has also been seen to decrease the self-reported incidence of illness in endurance athletes. So far, there is no firm evidence as to precisely which aspect of the immune system is affected by glutamine feeding during the transient immunodepression that occurs after prolonged, strenuous exercise. However, there is increasing evidence that neutrophils may be implicated. Other aspects of glutamine and glutamine supplementation are also addressed.     

Temporal changes in the oxidation state in in vitro blood

The rates at which the paramagnetic compounds deoxyhemoglobin (Hb) and methemoglobin (MHb) form in vivo within an area of hemorrhage are unknown. The present experiment establishes the baseline concentrations and rates of change in paramagnetic hemoglobin concentrations, as well as the pH in normal heparinized and clotted human blood maintained in vitro at 37 degrees C under anaerobic conditions over 30 hours. There was a moderate increase in Hb concentration in normal heparinized blood (average increase was 15.5%, rate = 0.50%/hour) and a slight increase in MHb concentration in the heparinized blood and clots (average increase was 1.4%, rate = 0.044%/hour). A second experiment was done to verify the activity of the RBC systems responsible for maintaining the hemoglobin molecule in the reduced state. Conversion of MHb to Hb in these samples proceeded at a rate of 5.6%/hour. In a third experiment, blood from 11 normal subjects maintained at 4 degrees C 25 degrees C was analyzed for MHb concentration over the course of 28 days. The level of MHb formation remained in the range of normal for at least 11 days in all subjects. The authors conclude that at basal conditions created in vitro, the blood levels of both Hb and MHb remain at relatively low levels. Therefore, if the accumulation of Hb and/or MHb occurs in acute in vivo hematomas it must be driven by intrinsic tissue factors.     

Carcinoma in situ in cryptorchid testes in post-pubertal patients]

The pathohistologic analysis of testis sections of 37 postpuberty patients with different types of cryptorchism is performed. The tissue samples were taken during orchiopehy, fixed in Bouin's solution and treated by the standard histologic techniques. The morphologic criteria are presented for identification of the presence of the so called carcinoma in situ cells found in two cases. Besides, in 13 patients rare, mainly single, atypical germinative cells were found in a smaller number of the seminiferous tubules. It has been concluded that the presence of carcinoma in situ cells in undescended testes of some patients and considering the simple way of sampling, lack of complications and high reliability of the diagnostic procedure, it is absolutely justified to take routine biopsy of testes during orchiopexy in each postpuberty and perhaps prepuberty patient.     

我国医用辐射防护研究概况

医学放射学技术的迅速发展及介入放射学在临床广泛应用，使更多的人受到电离辐射的照射，同时也促进了医疗照射防护工作的发展。文中重点综述了我国医用辐射防护工作者近年来在Ｘ射线ＣＴ的医疗照射防护、对介入放射学工作者的剂量监测以及应用医疗照射防护体系，降低医疗照射剂量等方面所作出的成绩和研究进展     

Interventions in the chest in children

The scope for image-guided intervention in the chest is very wide and encompasses procedures in the heart, pulmonary and systemic vasculature, lungs and pleural cavities, airway, and esophagus. This review describes the most important procedures that are usually performed by radiologists. Percutaneous drainage is now the most common method of treating both empyemas and lung abscesses in children. Although most lung biopsies are carried out by other means, percutaneous biopsy and localization are important alternatives for the diagnosis of focal lung lesions. Esophageal strictures are common in children and are usually best treated by balloon dilatation. The use of retrievable or biodegradable stents has recently been introduced for refractory esophageal strictures. Similarly, balloon dilatation and stenting are now increasingly used in children with stenosis or extrinsic compression of the trachea or bronchi.     

Serum zinc in athletes in training

Serum zinc was determined using atomic absorption spectrophotometry in 160 training athletes (57 females) in the morning at rest. In 23.3% of the male and 43% of the female athletes, serum Zn was lower than the limit accepted for the normal range (75 microgram/dl or 11.5 mumol/l). The average serum Zn (96.7 +/- 12.6 microgram/dl) and the range of the values found in a control group of 15 young adult males did not differ from the accepted values in the literature. In 22 randomly selected male athletes, serum Zn fractions were determined using polyethylene glycol precipitation at pH 7.1; 22.2% of total Zn was bóund to alpha2-macroglobulin, the ratio being very close to 1 atom of metal per molecule of globulin. The possible reasons that may influence the serum Zn level in athletes are discussed with regard to the present knowledge in both exercise physiology and metabolism of zinc in man.