某矿井及选煤厂建设项目职业病危害预评价

目的识别、评价本项目可能存在的职业病危害因素,确定建设项目的职业病危害类别,保护劳动者健康,预防职业病的发生。方法采用检查表法、类比法和定量分级法相结合的原则进行评价。结果本项目可行性研究报告的选址、总平面布置、职业病防护措施、建筑卫生学、卫生辅助设施及个人防护用品、应急救援措施、职业卫生专项经费概算等的设计基本符合卫生学要求。经类比分析,项目生产过程中可能产生的毒物和γ放射线强度能够符合国家卫生标准要求;经采取有效的职业病防护措施和个人防护措施后,可以减轻煤尘和噪声对工人健康的危害。结论由于生产过程中可能产生CO,本项目属严重职业病危害的建设项目。经分析,该项目生产过程中产生的职业病危害是可以预防和控制的。

Volumetric fraction measurement in oil-water-gas multiphase flow with dual energy gamma-ray system

Volumetric fraction distribution measurement is a constituent part of process tomography system in oil-water-gas multiphase flow. With the technological development of nuclear radial inspection, dual-energy γ-ray techniques make it possible to investigate the concentration of the different components on the cross-section of oil-water-gas multiphase pipe-flow. The dual-energy gamma-ray technique is based on materials attenuation coefficients measurement comprised of two radioactive isotopes of 241Am and 241Cs which have emission energies at 59.5 keV and 662 keV in this project. Nuclear instruments and data acquisition system were designed to measure the material’s attenuation dose rate and a number of static tests were conducted at the Multiphase Laboratory, Institute of Mechanics, Chinese Academy of Sciences. Three phases of oil-water-gas media were inves- tigated for their possible use to simulate different media volumetric fraction distributions in experimental vessels. Attenuation intensities were measured, and the arithmetic of linear attenuation coefficients and the equations of volumetric fractions were studied. Investigation of an unexpected measurement error from attenuation equations revealed that a modified arithmetic was involved and finally the system achieved acceptable accuracy in experimental research.

Study on absorption coefficients of dual-energy γ-rays in determining phase fractions of multiphase flows

This paper discusses the principle and mathematical method to measure the phase fractions of multiphase flows by using a dual-energy gamma-ray system. The dual-energy gamma-ray device is composed of radioactive isotopes of 241Am and 137Cs with emission energies of 59.5 keV and 662 keV respectively. A rational method to calibrate the absorption coefficient was introduced in detail. The statistical error has been analyzed on the basis of the accurate absorption coefficient which enables determination phrase fractions almost independent of the flow regime. Improvement has been achieved on the measurement accuracy of phase fractions.

Clinical study on gefitinib combined with γ-ray stereotactic radiotherapy for senile patients with adenocarcinoma of lung as the first-line regimen

Objective: The aim of our study was to evaluate the efficacy and safety of gefitinib combined with γ-ray stereo-tactic radiotherapy for senile patients with adenocarcinoma of lung as the first-line regimen. Methods: The 153 senile patients with adenocarcinoma of lung were divided into 4 groups according to the therapy method. Group A was the 35 patients treated with gefitinib combined with γ-ray stereotactic radiotherapy. Group B was the 45 patients treated with γ-ray stereotactic radio-therapy. Group C was the 42 patients treated with gefitinib. Group D was the 31 patients treated with best supportive therapy. The patients received gefitinib of 250 mg/d from the first day until disease progression or other reasons. The patients were treated with γ-ray stereotactic radiotherapy from the second day. Dose curve of this group of cases was 50%-80%. Encircled dose was 4.0-6.5 Gy per fraction and the range of total dose was 36-48 Gy. The total number of treatment was 8-12 and treated six times every week. Results: All the patients were examined by enhanced double helix CT at the second month. The tumor response rate (RR) of group A was 68.6% (24/35). Disease control rate (DCR) was 88.6% (31/35). The median survival time (MST) was 13.4 months (range 3-34 months ) and the progression-free survival (PFS) was 7.8 months. The overall 1-year survival rate was 40.0% (14/35). The main side effects included skin rash and diarrhea. The RR of group B was 51.1% (23/45). DCR was 71.1% (32/45). MST was 9.6 months (range, 3-18 months ) and PFS was 5.3 months. The overall 1-year survival rate was 15.6 % (7/45). The RR of group C was 40.5 % (17/42). DCR was 61.9% (26 /42). MST was 10.3 months (range, 3-26 months ) and PFS was 5.1 months. The overall 1-year survival rate was 35.7 % (15/42). The main side effects included skin rash and diarrhea. The MST of group D was 5.6 months (range, 2-11 months ) and PFS was 1.7 months. The overall 1-year survival rate was 0. The short-term therapeutic effects (RR) of group A was higher than group C (P = 0.014 < 0.05, χ2 = 6.053) but has no significant difference with group B (P = 0.116 > 0.05, χ2 = 2.477). The long-term therapeutic effects (overall 1-year survival rate) of group A was higher than group B (P = 0.014 < 0.05, χ2 = 6.077) but has no significant difference with group C (P = 0.642 > 0.05, χ2 = 0.216). Conclusion: Gefitinib combined with γ-ray stereotactic radiotherapy is feasible and effective for treatment in senile patients with adenocarcinoma of lung as the first-line regimen.

Isolation of Uranium by Anionic Exchange Resins

A separation methodology to isolate natural uranium from its radioactive daughters： Th, Ra, Bi, Pb, Pa and Po, was developed using an only one anion exchange resin and varying concentrations of HC1 solutions. Three types of anion exchange resins were tested and the separation process was followed by gamma and alpha spectrometry. Uranium can be quantitatively isolated from its descendants using Dowex IX8 （20-50 mesh） or Amerlite IRA （100 mesh） resins in three steps： using 4 and 8 mol/L-1 HCI and water to recover uranium. The method is easy, quick, and inexpensive.

The Effectiveness of Radiation Damage Reduction in Mice by Laser Light in Dependence of the Time Interval between Exposures

A research was carried out to determine the period of time during which it is possible to reduce the radiation damage in mice by means of laser radiation （650 nm） after gamma irradiation. First, the mice were exposed to γ- radiation （whole body irradiation）, then after 2 h or 24 h they were irradiated with laser radiation. The results of these studies have shown that the use of laser irradiation to reduce radiation damage in mice is effective 24 h after the exposure to 5 Gy ionizing radiation which leads to the bone-marrow clinical form of the ARS （Acute radiation sickness）. In case of the lethal dose of ionizing radiation 7 Gy （the transitional clinical form of the ARS）, the increase in life expectancy of mice is observed using laser radiation both 2 and 24 h after the exposure to γ- radiation, but the effectiveness of the laser used 2 h after the ionizing radiation is significantly more efficient.

富硒螺旋藻对大鼠胸部γ射线照射所致早期肺肝纤维增生的防治效果观察

为放射性肺炎的防治探索开辟新途径。富硒螺旋藻对辐射诱发的早期肺、肝的纤维增生有一定的防治效果。

Gefitinib combined with γ-ray stereotactic body radiation therapy has better efficacy than gefitinib alone for senile lung adenocarcinoma patients with EGFR mutations as first-line regimen

Objective： The senile lung adenocarcinoma patients harboring an activating epidermal growth factor receptor （EGFR） mutation shows good and rapid response to EGFR tyrosine kinase inhibitors （TKIs）. Whether gefitinib combined with y-ray stereotactic body radiation therapy has better efficacy than gefitinib alone for senile lung adenocarcinoma patients with EGFR mutations as first-line regimen is still under investigation. Methods： The 42 senile lung adenocarcinoma patients with EGFR mutations were divided into 2 groups according to the therapy method. Group A was the 22 patients treated with gefitinib combined with y-ray stereotactic body radiation therapy （SBRT）. Group B was the 20 patients treated with gefitinib alone. All of the patients received gefitinib of 250 mg/d from the first day until disease progression or other reasons. The patients of Group A were treated with y-ray stereotactic body radiation therapy from the second day. Radiation fields included the primary lesions and the integration of lymph nodes. Dose curve of this group was 50%-80%. Encircled dose was 4.0-6.5 Gy per fraction and the range of total dose was 40-52 Gy. We treated the patients 8-12 times and treated five times every week. Results： All the patients were examined by enhanced double helix CT at the second month. The tumor response rate （RR） of group A was 81.8% （18/22）. Disease control rate （DCR） was 90.9% （20/22）. The median overall survival （OS） was 24.2 months （range 8-58 months ） and the progression-free survival （PFS） was 18.6 months. The overall 1-year survival rate was 72.3% （16/22） and 2-year survival rate was 54.5% （12/22）. The main side effects included skin rash and diarrhea. The RR of group B was 50.0 % （10/20）. DCR was 75.0% （15/20）. OS was 17.4 months （range 6-32 months ） and PFS was 12.1 months. The overall 1-year survival rate was 60.0% （12/20） and 2-year survival rate was 40.0% （8/20）. The main side effects included skin rash and diarrhea. The group A who were treated with gefitinib combined with y-ray stereotactic body radiation therapy had a higher short term therapeutic effects （RR） and long term therapeutic effects （OS） than group B who were treated with gefitinib alone respectively （81.8% vs 50.0%, P = 0.029 〈 0.05, x2 = 4.773 and 24.2 vs 17.4, P = 0.024 〈 0.05, X2 = 5.098）. Conclu. sion： Gefitinib combined with y-ray stereotactic body radiation therapy has better efficacy than gefitinib alone for senile lung adenocarcinoma patients with EGFR mutations as first-line regimen. The side affects are acceptable.