Use of low-dose computed tomography to assess pulmonary tuberculosis among healthcare workers in a tuberculosis hospital

BACKGROUND: According to the World Health Organization, China is one of 22 countries with serious tuberculosis (TB) infections and one of the 27 countries with serious multidrug-resistant TB strains. Despite the decline of tuberculosis in the overall population, healthcare workers (HCWs) are still at a high risk of infection. Compared with high-income countries, the TB prevalence among HCWs is higher in low- and middle-income countries. Low-dose computed tomography (LDCT) is becoming more popular due to its superior sensitivity and lower radiation dose. However, there have been no reports about active pulmonary tuberculosis (PTB) among HCWs as assessed with LDCT. The purposes of this study were to examine PTB statuses in HCWs in hospitals specializing in TB treatment and explore the significance of the application of LDCT to these workers. METHODS: This study retrospectively analysed the physical examination data of healthcare workers in the Beijing Chest Hospital from September 2012 to December 2015. Low-dose lung CT examinations were performed in all cases. The comparisons between active and inactive PTB according to the CT findings were made using the Pearson chi-square test or the Fisher’s exact test. Comparisons between the incidences of active PTB in high-risk areas and non-high-risk areas were performed using the Pearson chi-square test. Analyses of active PTB were performed according to different ages, numbers of years on the job, and the risks of the working areas. Active PTB as diagnosed by the LDCT examinations alone was compared with the final comprehensive diagnoses, and the sensitivity and positive predictive value were calculated. RESULTS: A total of 1 012 participants were included in this study. During the 4-year period of medical examinations, active PTB was found in 19 cases, and inactive PTB was found in 109 cases. The prevalence of active PTB in the participants was 1.24%, 0.67%, 0.81%, and 0.53% for years 2012 to 2015. The corresponding incidences of active PTB among the tuberculosis hospital participants were 0.86%, 0.41%, 0.54%, and 0.26%. Most HCWs with active TB (78.9%, 15/19) worked in the high-risk areas of the hospital. There was a significant difference in the incidences of active PTB between the HCWs who worked in the high-risk and non-high-risk areas (odds ratio [OR], 14.415; 95% confidence interval (CI): 4.733 – 43.896). Comparisons of the CT signs between the active and inactive groups via chi-square tests revealed that the tree-in-bud, cavity, fibrous shadow, and calcification signs exhibited significant differences (P = 0.000, 0.021, 0.001, and 0.024, respectively). Tree-in-bud and cavity opacities suggest active pulmonary tuberculosis, whereas fibrous shadow and calcification opacities are the main features of inactive pulmonary tuberculosis. Comparison with the final comprehensive diagnoses revealed that the sensitivity and positive predictive value of the diagnoses of active PTB based on LDCT alone were 100% and 86.4%, respectively. CONCLUSIONS: Healthcare workers in tuberculosis hospitals are a high-risk group for active PTB. Yearly LDCT examinations of such high-risk groups are feasible and necessary. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40249-017-0274-6) contains supplementary material, which is available to authorized users

Optimization and resilience of complex supply-demand networks

Acknowledgments This work was supported by NSF under Grant No. 1441352. SPZ and ZGH were supported by NSF of China under Grants No. 11135001 and No. 11275003. ZGH thanks Prof Liang Huang and Xin-Jian Xu for helpful discussions.Peer reviewedPublisher PD

Microstructure evolution of extruded Mg-Gd-Y magnesium alloy under dynamic compression

AbstractFor the purpose of investigating the microstructure evolution and deformation behavior of magnesium under high strain rates, the Split Hopkinson Pressure Bar (SHPB) apparatus was used under high strain rates from 755 s−1 to 2826 s−1 in the present work at room temperature. The microstructures of extruded Mg-Gd-Y Magnesium alloy under different strain rates and along different compression directions were observed by metallographic microscope. The results show that, microstructures of extruded Mg-Gd-Y Magnesium alloy along ED, TD and ND compression directions are sensitive to strain rates. The amount of twins firstly increases and then decreases with strain rates being increased, and the recrystal grains increase and grow up. When the strain rate reaches 2500 s−1, the adiabatic shear band (ASB) begins to form. The formation process of the adiabatic shear band can be divided into three stages. In the first stage, under the impact load a great deal of twins form and the deformation mechanism is twinning. In the second stage, discontinuous ASB forms due to twins adjusting the directions of located grains and the deformation mechanisms are twinning and non-basal slip. In the last stage, non-basal slip turns to basal slip and continuous ASB forms. The dynamic compression fracture mechanism of extruded Mg-Gd-Y Magnesium alloy is multi-crack propagation

The application of daily interruption in the treatment of analgesia and sedation in general ICU

目的  探讨在综合ICU镇痛镇静患者护理方面实施每日唤醒疗法护理的方法和效果。方法  选择在ICU进行持续镇痛镇静治疗>24h的患者共90例，实施每日唤醒和相应护理计划并观察记录。结果  实施每日唤醒后，镇痛镇静药物用量减少，机械通气时间减少，与镇静相关的躁动、谵妄事件减少，住ICU时间缩短。结论  ICU镇痛镇静患者实施每日唤醒可有利于其疾病恢复，减少镇静相关不良事件，值得临床关注，但必须加强病情监测和安全护理。Objective: To explore method and effect of daily interruption therapy in the treatment of analgesia and sedation in general ICU. Methods: 90 patients in ICU, who had been treated with continuous analgesia therapy within 24 hours, were selected and would receive daily interruption therapy and corresponding nursing. Results: Analgesic dosage of sedative drugs was reduced, together with mechanical ventilation time, and delirium events associated with calm restless, ICU stay was shortened after the implement of daily interruption therapy and nursing. Conclusion: The application of daily interruption in general ICU is beneficial to their disease recovery, reduce adverse events related with calmness, worthy of clinical attention, but it is imperative to improve the security of condition monitoring and nursing