The r.b.e. of Fast Fission Neutrons (2 MeV) for Chronic Radiation Damage of the Large Bowel of Rats after Single Dose and Fractionated Irradiation

Summary

Late damage in the rectum of rats was studied after local irradiation with 2 MeV fast fission neutrons and the results were compared with those for 300 kV X-rays. A similarity between latency times, and between clinical, gross pathological and histological appearances of the rectal obstruction after the two types of radiation was observed. The r.b.e. evaluated from ED 50 200 days values was 1·8 for single doses, 2·1 for two fractions and 3 for five fractions and these are similar to r.b.e.s from other investigations of chronic intestinal radiation damage. Using linear quadratic analysis, a limiting r.b.e. of 5 was obtained. The β-values are similar for both radiation qualities. Because of the high γ-contamination (25 per cent) in the RENT I beam a possible correction of the r.b.e. for neutrons only, assuming interaction, is discussed.     

《世界卫生组织狂犬病专家磋商会第三版报告》更新与解读

2018年4月,世界卫生组织(World Health Organization,WHO)公布了《WHO狂犬病专家磋商会第三版报告》,总结和展示了近年来世界范围内在狂犬病免疫、预防、控制和国际间合作等方面的研究结果,在狂犬病病毒学、人类狂犬病防控、人用狂犬病疫苗及狂犬病免疫球蛋白使用、犬狂犬病防控等方面展示了新的证据,提出了新的更改和推荐意见。尤其在狂犬病病毒学、人用狂犬病疫苗和狂犬病免疫球蛋白使用方面进行了较大的修改,重点关注方案的可行性、疫苗接种程序的简化、成本效益的提高,并对以往未涉及的许多细节给出了明确推荐意见。提出到2030年在全球范围内消除由犬传播的人狂犬病病例的战略目标及其实施方案。作者就主要的更新内容进行解读,揭示其临床意义。     

把控科技查新工作站报告质量的探讨

本文阐述我校从建立查新初、终审核制度,重视查新工作过程的各细节问题等,把控报告、审核的质量,提升查新工作站的服务水平作用。     

Quality assurance of radiopharmaceuticals. Report of a joint working party: the UK Radiopharmacy Group and the NHS Pharmaceutical Quality Control Committee

In this issue, the UK Radiopharmacy Group presents its third report on the Quality Assurance of Radiopharmceuticals. This concentrates on facilities which prepare only short-lived materials (shelf-life <24 hours) on site, which covers the majority of units within the UK, but is applicable to all radiopharmacies. As has come to be expected, the advice is comprehensive and provides sound interpretation of both current and potential legislation/regulations/guidelines. It will enable existing units to carry out a rapid audit of their documentation and prove invaluable to those planning new facilities. Given the litigious milieu in which we now practise, this is a timely document.     

被动吸烟对豚鼠高空减压气泡生成影响的初步观察

观察了３０只豚鼠于密闭舱内被动吸入卷烟烟雾对随后高空减压心前区气泡出现的影响。结果表明：在上述２种吸入卷烟烟雾的条件下，减压气泡的首次出现时间和气泡等级与对照组相比无显著差异。初步提示减压露前短时间大量吸烟不会影响高空减压病的发生。     

Report of the U.K. Government's Advisory Committee on Irradiated and Novel Foods

Summary

Oxidation processes of radiation-generated three-electron-bonded intermediates derived from methionine Met₂ and Met[S∴X] (X = Cl, Br) were investigated through reaction with tryptophan and tyrosine, using the optical pulse radiolysis method. Bimolecular rate constants have been measured for the reactions Met₂ with TrpH(k = 3·8 × 10⁸ dm³ mol^?1 s^?1 and k = 4·9 × 10⁸ dm³ mol^?1 s^?1 at pH 1 and 4·3, respectively) and Met₂ with tyrosine, k = 3·8 × 10⁷ dm³ mol^?1 s^?1. Rate constants for intermolecular transformation of Met[S∴Br] and Met[S∴Cl] into TrpH^+· or Trp· were also estimated. They varied from 4·7 × 10⁸ dm³ mol^?1 s^?1 (bromide species) to 1·0 × 10⁹ dm³ mol^?1 s^?1 (chloride species). It has also been established that azide radicals , N·₃ in contrast to dihalide radicals do not form transients of Met[S∴X] (X = N₃)-type. However, oxidation of N^?₃ by Met₂ occurs with a bimolecular rate constant of 2·8 × 10⁸ dm³ mol^?1 s^?1. These results are discussed in the light of some equilibria which have been proposed earlier for methionine-halide systems.     

The Effect of Body Temperature on the Sensitivity of the Haemopoietic Tissues of Mice to X-irradiation

The effect of x-irradiation on the haemopoietic tissues of mice while they are at body temperatures of 15°c is described.

Histological examination of the spleen and femoral bone-marrow revealed no differences between groups of animals irradiated at body temperatures of 15°c and those irradiated at normal body temperatures and then cooled to 15°c over the dose-range 0 to 950 r.

The total peripheral-leucocyte counts were compared with those obtained in previous experiments when animals were irradiated at body temperatures of 1°c and at normal body temperatures. Statistical analysis shows that on the evidence of leucocyte counts five days after irradiation, exposure of animals to x-rays while they are at body temperatures of 15°c affords slight protection to the haemopoietic tissues, which is much less than the protection provided at body temperatures of 1°c when the animals are severely hypoxic. Cooling to 15°c after irradiation affords no detected radioprotection.     

Management of Lung Nodules and Lung Cancer Screening During the COVID-19 Pandemic: CHEST Expert Panel Report

BackgroundThe risks from potential exposure to coronavirus disease 2019 (COVID-19), and resource reallocation that has occurred to combat the pandemic, have altered the balance of benefits and harms that informed current (pre-COVID-19) guideline recommendations for lung cancer screening and lung nodule evaluation. Consensus statements were developed to guide clinicians managing lung cancer screening programs and patients with lung nodules during the COVID-19 pandemic.MethodsAn expert panel of 24 members, including pulmonologists (n = 17), thoracic radiologists (n = 5), and thoracic surgeons (n = 2), was formed. The panel was provided with an overview of current evidence, summarized by recent guidelines related to lung cancer screening and lung nodule evaluation. The panel was convened by video teleconference to discuss and then vote on statements related to 12 common clinical scenarios. A predefined threshold of 70% of panel members voting agree or strongly agree was used to determine if there was a consensus for each statement. Items that may influence decisions were listed as notes to be considered for each scenario.ResultsTwelve statements related to baseline and annual lung cancer screening (n = 2), surveillance of a previously detected lung nodule (n = 5), evaluation of intermediate and high-risk lung nodules (n = 4), and management of clinical stage I non–small-cell lung cancer (n = 1) were developed and modified. All 12 statements were confirmed as consensus statements according to the voting results. The consensus statements provide guidance about situations in which it was believed to be appropriate to delay screening, defer surveillance imaging of lung nodules, and minimize nonurgent interventions during the evaluation of lung nodules and stage I non–small-cell lung cancer.ConclusionsThere was consensus that during the COVID-19 pandemic, it is appropriate to defer enrollment in lung cancer screening and modify the evaluation of lung nodules due to the added risks from potential exposure and the need for resource reallocation. There are multiple local, regional, and patient-related factors that should be considered when applying these statements to individual patient care.     

新疆低温奶消费情况调研报告

本文旨在探讨影响新疆低温乳消费市场的限制性因素及相应的对策。调研通过网络调查问卷和实地调研走访相结合的方式,从乳制品消费结构、消费能力,低温奶认知、低温奶购买意愿、购买便利性、购买偏好及健康饮奶习惯等方面分析影响新疆低温乳消费市场的因素。结果显示:32.93%的消费者不了解乳中生物活性物质(如乳铁蛋白)的热敏性,39.97%的消费者不能区分各类液态乳产品,47.64%的消费者有煮沸巴氏杀菌乳后饮用的习惯;43.21%的消费者担心未消毒彻底,存在细菌,36.30%的消费者认为加热后可增加营养价值和香味;72.64%的消费者曾感到购买巴氏杀菌乳不方便;54.85%的消费者认为本地品牌更新鲜、更健康。结果启示:本地乳企应该充分利用在当地的良好品牌信誉度和牧场资源,尽早布局低温奶市场,通过研发高品质低温乳制品、普及科学饮奶理念、改善冷链物流能力、完善购物体验和精细化服务能力等手段,提高生产竞争力,抵御进口乳制品和常温乳对当地乳品市场的冲击,占领区域低温奶消费市场。     

Proton MR spectroscopy in predicting the increase of perfusion MR imaging for WHO grade II gliomas

Purpose:

To investigate the correlation between the metabolite ratios obtained from proton magnetic resonance (MR) spectroscopy and those obtained from MR perfusion parameters (relative cerebral blood volume [rCBV]) in a cohort of low‐grade glioma (LGG).

Materials and Methods:

Patients underwent prospectively conventional MR, proton magnetic resonance spectroscopy (¹HMRS), and perfusion‐weighted images (PWI). Statistical analyses were performed to determine the correlative and independent predictive factors of rCBVmax and the metabolite ratio thresholds with optimum sensitivity and specificity.

Results:

Thirty‐one patients were included in this study. Linear correlations were observed between the metabolic ratios (lactate [Lac]/creatine [Cr], choline [Cho]/N‐acetyl‐aspartate [NAA], free‐lipids/Cr) and rCBVmax (P < 0.05). These metabolic ratios were determined to be independent predictive factors of rCBVmax (P = 0.027, 0.011 and 0.032, respectively). According to the receiver operating characteristic curves, the cutoff values of the metabolic ratios to discriminate between the two populations of rCBVmax (<1.7 versus = 1.7) were 1.72, 1.54, and 1.40, respectively, with a sensitivity = 75% and a specificity >95% for Lac/Cr.

Conclusion:

This study demonstrated consistent correlations between the data from ¹HMRS and PWI. The Lac/Cr ratio predicts regional hemodynamic changes, which are themselves a useful biomarker of clinical prognosis in patients with LGG. As such, this ratio may provide a new parameter for making improved clinical decisions. J. Magn. Reson. Imaging 2012;35:543‐550. © 2011 Wiley Periodicals, Inc.