A Comparative Study of Electron Radiation Responses of Pu2Zr2O7 and La2Zr2O7: An ab initio Molecular Dynamics Study

In this study, the response of Pu₂Zr₂O₇ and La₂Zr₂O₇ to electronic radiation is simulated, employing an ab initio molecular dynamics method. It is shown that Pu₂Zr₂O₇ undergoes a crystalline-to-amorphous structural transition with 0.3% electronic excitation, while for La₂Zr₂O₇, the structural amorphization occurs with 1.2% electronic excitation. During the microstructural evolution, the anion disorder further drives cation disorder and eventually results in the structural amorphization of Pu₂Zr₂O₇ and La₂Zr₂O₇. The difference in responses to electron radiation between Pu₂Zr₂O₇ and La₂Zr₂O₇ mainly results from the strong correlation effects between Pu 5f electrons and the smaller band gap of Pu₂Zr₂O₇. These results suggest that Pu₂Zr₂O₇ is less resistant to amorphization under local ionization rates that produce a low level of electronic excitation, since the level of the concentration of excited electrons is relatively low in Pu₂Zr₂O₇. The presented results will advance the understanding of the radiation damage effects of zirconate pyrochlores.     

Oral iron chelators--development and application

Iron chelation therapy is the only therapeutic approach that leads to enhanced iron excretion in beta-thalassaemia major and other transfusion-dependent patients. Although desferrioxamine has been used in such treatment over the last three decades, it is not an ideal drug due to its poor oral availability. Consequently extensive research effort has been directed towards the identification of non-toxic, orally active iron chelators. An ideal candidate must possess a range of critical physicochemical and biological properties, such as high selectivity and affinity for iron(III), tightly controlled distribution and metabolic profiles and low toxicity. Unfortunately, hexadentate ligands are generally associated with poor oral bioavailability, whereas many tridentate and bidentate molecules are orally active. The tridentate triazoles have been investigated for clinical potential; they are readily absorbed from the gastrointestinal tract and promote iron excretion with high efficacy. In similar fashion, several bidentate hydroxypyridinones have been demonstrated to possess potential as oral chelating agents.     

Studies on the T4+2H4+ cell of peripheral blood lymphocyte in systemic lupus erythematosus]

The cell surface phenotype of peripheral blood lymphocytes in patients with systemic lupus erythematosus (SLE) was studied with the anti-T4+, T8+ and T4+2H4+ monoclonal antibodies by flow cytometry. 13 patients with active SLE had a markedly low percentage of T4+2H4+ cells but had normal percentage of T8+ cells. Our results reveal that the influence of T cell to B cell is not only because of the quantity of T cells, also because of the function of T cells. The abnormality of T4+2H4+ cells may be important in the pathogenesis of SLE.     

Genetic marking shows that Ph+ cells present in autologous transplants of chronic myelogenous leukemia (CML) contribute to relapse after autologous bone marrow in CML

Relapse after autologous bone marrow transplantation for chronic myelogenous leukemia (CML) can be due either to the persistence of leukemia cells in systemic tissues following preparative therapy, or due to the persistence of leukemia cells in the autologous marrow used to restore marrow function after intensive therapy. To help distinguish between these two possible causes of relapse, we used safety-modified retroviruses, which contain the bacterial resistance gene NEO, to mark autologous marrow cells that had been collected from patients early in the phase of hematopoietic recovery after in vivo chemotherapy. The cells were then subjected to ex vivo CD34 selection following collection and 30% of the bone marrow were exposed to a safety-modified virus. This marrow was infused after delivery of systemic therapy, which consisted of total body irradiation (1,020 cGy), cyclophosphamide (120 mg/kg), and VP-16 (750 mg/m2). RT PCR assays specific for the bacterial NEO mRNA, which was coded for by the virus, and the bcr-abl mRNA showed that in two evaluable CML patients transplanted with marked cells, sufficient numbers of leukemia cells remained in the infused marrow to contribute to systemic relapse. In addition, both normal and leukemic cells positive for the retroviral transgenome persisted in the systemic circulation of the patients for at least 280 days posttransplant showing that the infused marrow was responsible for the return of hematopoiesis following the preparative therapy. This observation shows that it is possible to use a replication-incompetent safety-modified retrovirus in order to introduce DNA sequences into the hematopoietic cells of patients undergoing autologous bone marrow transplantation. Moreover, this data suggested that additional fractionation procedures will be necessary to reduce the probability of relapse after bone marrow transplantation in at least the advanced stages of the disease in CML patients undergoing autologous bone marrow transplantation procedures.     

2004-2012年攀枝花市其他感染性腹泻病流行病学特征分析

目的分析2004-2012年攀枝花市其他感染性腹泻病（除霍乱、痢疾、伤寒和副伤寒）的流行病学特征,为制定防控策略和措施提供科学依据。方法采用描述流行病学分析方法,对2004-2012年攀枝花市法定传染病报告系统中其他感染性腹泻病疫情资料进行分析。结果 2004-2012年攀枝花市共报告其他感染性腹泻病15 032例,无死亡病例,年平均发病率为149.63/10万;发病高峰在4-8月和10-12月,占病例总数的72.80%;男女性别比例为1.34∶1;发病以0-3岁年龄组为主,占病例总数的46.08%;散居儿童发病最高,占病例总数的52.47%,其次是学生和工人;报告实验室诊断病例296例,占病例总数的1.97%。结论攀枝花市其他感染性腹泻病发病具有明显的季节性发病高峰,应重点加强对0-3岁组散居儿童的预防和控制措施,提高感染性腹泻病原学诊断率。     

新疆自治区PICC专科护士多点执业认知与意愿的调查分析

目的调查新疆自治区PICC专科护士多点执业的认知与意愿,旨在为PICC专科护士多点执业的推行提供理论依据。方法采用PICC专科护士多点执业认知与意愿问卷,对新疆158名PICC专科护士进行问卷调查。结果 PICC专科护士对护士多点执业认知总得分为(33.11±7.62)分,护士能级、聘用类别、月收入、从事PICC护理工作为PICC专科护士多点执业认知的影响因素,可共同解释PICC专科护士多点执业认知得分总变异的45.00%。PICC专科护士多点执业意愿总得分为(84.93±9.27)分,年龄、工作年限、学历、聘用类别、能级为PICC专科护士多点执业意愿的影响因素,可共同解释PICC专科护士多点执业意愿得分总变异的23.60%。45.39%护士认为多点执业首先考虑的因素是法律保障;91.45%认为多点执业可以发挥自身专业特长;82.89%护士认为通过多点执业,可提高自身职业价值;88.16%护士认为,通过多点执业可提高自己的社会地位和增强职业认同感。结论新疆自治区PICC专科护士多点执业认知处于中等水平,多点执业意愿强烈。加强对低年资、学历及低能级护士的教育,提高她们护士多点执业认知,同时完善相关法律和多点执业监督体系,明确多点护士的职责,以稳步推进PICC专科护士多点执业向前发展。     

Chronic Active Hepatitis B with COVID-19 in Pregnancy: A Case Report

Currently, infection with coronavirus disease 2019 (COV-ID-19), caused by severe acute respiratory syndrome cor-onavirus 2 (SARS-CoV-2), during pregnancy is a p...     

Blast Resistance of 240 mm Building Wall Coated with Polyurea Elastomer

Enhancing the blast resistance of building walls is a research hotspot in the field of anti-terrorism and explosion protection. In this study, numerical simulation and experimental verification were combined to analyze the failure phenomenon of brick masonry wall and sprayed polyurea-reinforced brick wall under contact explosion and determine the failure response parameters of the wall. The failure limit, mode, and mechanism of a 240 mm wall without reinforcement and strengthened with polyurea elastomer under different strength loads were investigated. Under contact explosion, the increase in the size of the blasting pit of the 240 mm wall gradually slowed down after the dose was increased to higher than 0.5 kg. Thereafter, the energy of the explosive load was released by splashing wall fragments as well as by deflecting and movement of the wall. The results show that the 240 mm walls sprayed with polyurea elastomer had outstanding anti-explosion performance because it wraps the damaged area and fragments of masonry wall inside the polyurea layer. When the thickness of the polyurea layer increases to 8 mm, the damaged area of the masonry wall decreases by 55.6% compared with that without reinforcement. The numerical simulation results were in good agreement with the experimental results.