Search

Few studies have evaluated the short-term association between hospital admissions and individual exposure to ambient particulate matter (PM2.5). Particularly, no studies focused on hospital admissions for chronic obstructive pulmonary disease (COPD) at individual level. We assessed the short-term effects of PM2.5 on hospitalization admissions for COPD in Guangzhou, China, during 2014–2015, based on satellite-derived estimates of ambient PM2.5 concentrations at 1-km resolution near the residential address as individual-level exposure for each patient. 40,002 patients with COPD admitted to 110 hospitals were included in this study. A time-stratified case-crossover design with conditional logistic regression models was applied to assess the effects of PM2.5 based on 1-km grid data of aerosol optical depth provided by National Aeronautics and Space Administration on hospital admissions for COPD. Further, we performed stratified analyses by individual demographic characteristics and season of hospital admission. 10 µg/m3 increase in individual-level PM2.5 was associated with an increase of 1.6% (95% confidence interval [CI]: 0.6%, 2.7%) in hospitalization for COPD at lag of 0–5 days. The impact of PM2.5 on hospitalization for COPD was greater significantly in male and patients admitted in summer and accordingly the impacts may be exacerbated in the context of global warming. Our study strengthened the evidence for the adverse effect of PM2.5 based on satellite-based individual-level exposure data.

Background Benzobicyclon (BBC) is a β-triketone herbicide (bTH) used in rice paddy fields. It has the advantages of high efficiency, low toxicity, high crop safety, and good environmental compatibility, and shows efficacy against paddy weeds resistant to other types of herbicides. However, as some important indica rice varieties are susceptible to BBC, BBC is currently only registered and applied in japonica rice cultivation areas. Results By analyzing haplotypes of the bTHs broad-spectrum resistance gene HIS1 and phenotypes for BBC in 493 major indica rice accessions in China, we identified a novel non-functional allelic variant of HIS1 in addition to the previously reported 28-bp deletion. Through detection with markers specific to the two non-functional mutations, it was clear that 25.4% of indica conventional varieties, 59.9% of fertility restorers, and 15.9% of sterile lines were susceptible to BBC. In addition, due to natural allelic variations of the HIS1 gene in the sterile and restorer lines, some two-line hybrid sterile lines were sensitive to bTHs, and the corresponding restorers were resistant. We showed the potential effectiveness of using bTHs to address the issue of two-line hybrid rice seed purity stemming from the self-crossing of sterile lines during hybrid rice seed production. Finally, allelic variations of the HIS1 gene may also play an important role in the mechanized seed production of hybrid rice. Conclusions Our findings offer guidance for the application of BBC in indica rice areas and provide a non-transgenic approach to address the seed purity issue of two-line hybrid rice.

Zhi-Ying Zhan,1,2,* Qi Tian,3,* Ting-Ting Chen,1,* Yunshao Ye,3 Qiaoxuan Lin,3 Dong Han,1 Chun-Quan Ou1 1State Key Laboratory of Organ Failure Research, Department of Biostatistics, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, People’s Republic of China; 2Department of Health Care Management and Social Medicine, School of Public Health, Fujian Medical University, Fuzhou, People’s Republic of China; 3Department of Information Resources, Guangzhou Health Information Center, Guangzhou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Chun-Quan Ou Email ocq@smu.edu.cnPurpose: Chronic obstructive pulmonary disease (COPD) is a major cause of chronic diseases causing considerable social and economic burden globally. Despite substantial evidence on temperature-COPD association, few studies have investigated the acute effect of temperature variability (TV), a potential trigger of exacerbation of COPD disease, and it remains unknown what fraction of the disease burden of COPD is attributable to TV.Patients and Methods: Based on 71,070 COPD hospitalizations during 2013– 2015 in Guangzhou, China, we conducted a time-series analysis using quasi-Poisson regression to assess the association between TV and hospital admission for COPD after adjusting for daily mean temperature. Short-term TV was captured by the standard deviation of hourly or daily temperatures across various exposure days. We also provided the fraction (total number) of COPD attributable to TV. Stratified analyses by admission route, sex, age, occupation, marital status and season were performed to identify vulnerable subpopulations.Results: We found a linear relationship between TV and COPD hospitalization, with a 1°C increase in hourly TV and daily TV associated with 4.3% (95%CI: 2.2– 6.4) and 4.0% (2.3– 5.8) increases in COPD, respectively. The greater relative risks of TV identified males, people aged 0– 64 years, blue collar, and divorced/widowed people as vulnerable population. There were 12.0% (8500 cases) of COPD hospitalization attributable to hourly TV during the study period. Daily TV produced similar estimates of relative effects (relative risk) but grater estimates of absolute effects (attributable fraction) than hourly TV.Conclusion: We concluded that TV was an independent risk factor of COPD morbidity, especially among the susceptible subgroups. These findings would be helpful to guide the development of targeted public intervention.Keywords: epidemiology, COPD hospitalization, distributed lag non-linear model, time-series analysis, China

Objective— Increasing evidence shows that autoimmune response contributes importantly to pathogenesis of abdominal aortic aneurysm (AAA). This work was aimed to assess the possibly altered function of peripheral CD4 + CD25 + T regulatory cells (Tregs) that might breakdown immunologic self-tolerance in AAA patients. Methods and Results— Peripheral blood from 22 AAA patients, 11 patients with abdominal aortic atherosclerotic occlusive disease (AOD), and 32 healthy controls (HCs) was analyzed to determine the percentage of CD4 + CD25 + Tregs in the total CD4 + T-cell population and FOXP3 expression by means of flow cytometry. The frequencies of the CD4 + CD25 + Treg population were not significantly different between groups (AAA, 5.69±0.99%; AOD, 5.52±1.13%; HC, 5.88±1.55%; P >0.05). However, the frequency of CD4 + CD25 + FOXP3 + T cells in AAA patients (2.45±0.57%) was significantly lower than that in AOD group (3.41±0.72%; P P + CD25 + Tregs from AAA group than either of other 2 groups ( P + CD25 + Tregs from patients with AAA exhibited significantly less suppressive activity than those from AOD patients or HCs ( P + CD25 + T cells and CD4 + CD25 − T cells from AAA patients and HCs demonstrated that the primary regulatory defect is due to a dysfunction of CD4 + CD25 + Tregs, and not a resistance of CD4 + CD25 − responder T cells to suppression in AAA patients. Conclusion— Our data demonstrate a reduced level of FOXP3 expression in peripheral CD4 + CD25 + Tregs and decreased frequency of CD4 + CD25 + FOXP3 + T cells in a cohort of AAA patients enrolled in the study, which leads to a functional deficiency of CD4 + CD25 + Tregs as a whole. This indicates an impaired immunoregulation by Tregs that may contribute to AAA pathogenesis.

We report the low threshold current density operation of strain-compensated In0.64Ga0.36As/In0.38Al0.62As quantum cascade lasers emitting near 4.94 mu m. By employing an enlarged strain-compensated structure and optimizing the injector doping density, a rather low threshold current density of 0.57 kA/cm(2) at 80K is achieved for an uncoated 20-mu m-wide and 2.5-mm-long laser.

We present a detailed study of lambda similar to 9.75 mu m GaAs/AIGaAs quantum cascade lasers. For a coated 2-mm-long and 40-mu m-wide laser, an optical power of 85 mu W is observed 95% duty cycle at 80 K. At a moderate driving pulse (1 kHz and 1% duty cycle), the device presents a peak power more than 20 mW even at 120 K. At 80 K, the fitted result of threshold current densities shows evidence of potential cw operation.

High-power operation of uncoated 22-mu m-wide quantum cascade lasers (QCLs) emitting at lambda approximate to 4.8 mu m is reported. The emitting region of the QCL structure consists of a 30-period strain-compensated In0.68Ga0.32As/In0.37Al0.63As superlattice. For a 4-mm-long laser in pulsed mode, a peak output power is achieved in excess of 2240mW per facet at 81K with a threshold current density of 0.64kA/cm(2). The effects of varying the cavity lengths from 1 to 4mm on the performances of the QCLs are analysed in detail and the low waveguide loss of only about 1.4 cm(-1) is extracted.

We report low-threshold high-temperature operation of 7.4 μm strain-compensated InGaAs/InAlAs quantum cascade lasers (QCLs). For an uncoated 22- μm-wide and 2-mm-long laser, the low-threshold current densities, i.e. 0.33 kA/cm2 at 81 K in pulsed mode and 0.64 kA/cm2 at 84 K in cw mode, are realized. High-temperature operation of uncoated devices, with a high value of 223 K, is achieved in cw mode.

We report on the realization of GaAs/AlGaAs quantum cascade lasers with an emission wavelength of 9.1 mu m above the liquid nitrogen temperature. With optimal current injection window and ridge width of 24 and 60 mu m respectively, a peak output power more than 500 mW is achieved in pulsed mode operation. A low threshold current density J(th) = 2.6 kA/cm(2) gives the devices good lasing characteristics. In a drive frequency of 1 kHz, the laser operates up to 20% duty cycle.

Objective: Combined resection for locally advanced (T4) gastric cancer may result in high morbidity and mortality. The aim of this study was to evaluate the clinicopathologic characteristics to determine the prognostic factors for T4 gastric cancers. Methodology: A total of 463 consecutive patients with gastric cancers were enrolled in this study. Among them, 63 patients received combined resections. Various clinicopathologic factors influencing survival rates were evaluated. Survival rates were calculated according to the Kaplan-Meier method. Prognostic factors were evaluated by the univariate and multivariate analysis. Results: Thirty-one patients (49.2%) received one additional organ resection and 32 patients (50.8%) received two or more additional organ resections. Curative resection was performed in 49 patients (77.8%). Multivariate analysis identified curative resection (hazard ratio 0.330; 95 percent confidence interval, 0.139-0.784; P = 0.012) and tumor diameter (> 7 cm) (hazard ratio, 3.589; the 95 percent confidence interval, 1.425-9.037; P = 0.007) as independent prognostic factor for patients with T4 gastric cancer undergoing combined resection. Conclusions: The use of aggressive multi-organ resection was recommended for patients with T4 gastric carcinoma, with tumor diameter as a useful indicator. Patients with relatively small tumor diameter (≤ 7cm) could benefit from multi-organ resections.

Tracheobronchial aspergillosis mainly involves the trachea, primary bronchus and segmental bronchus. The main symptoms including dyspnea, asthma and cough. Bronchoscopic findings supply the main evidence for diagnosis. Voriconazole has been widely used as azole antifungal agent in recent years, which is also a first-line drug in the treatment of invasive pulmonary aspergillosis (IPA), but rare report exists in the treatment of tracheobronchial aspergillosis. Two patients have been remitted with Voriconazole in this study, and it was found that Voriconazole could improve therapeutic effect and shorten therapeutic time with less adverse effects.

On the basis of anatomic studies, we have devised a new method of transferring the thoracodorsal nerve to reinnervate the paralytic deltoid or biceps muscles in an old traumatic injury of the associated nerve. It has been applied to a case of musculocutaneous nerve injury and two cases of axillary nerve injury with good results. The muscle functions have returned to normal within 1 and 2 years, respectively, as shown by electromyography and the muscular contractility test.

Objective To explore the easily applicable indicators of practical value to evaluate the prognosis of acute respiratory distress syndrome (ARDS). Methods Blood and biochemical tests and blood-gas analyses were performed upon entry into the ICUs, 12 h, 24 h, 48 h and 72 h after that in 72 ARDS patients (who were admitted to the ICUs of our hospital from January 2000 to December 2009). Then APACHE Π scores were achieved by combining relevant physiological parameters and laboratory results. Results There was a statistical difference between the death group and survival group at different time points upon entering the ICUs in terms of APACHE Π score, alveolar-arterial oxygen difference and arterial blood lactate clearance rate. PaO 2 /FiO 2 values were recorded to be statistically different between the death group and survival group 24 h, 48 h and 72 h, respectively after entry into the ICUs. In addition, registered linear regression existed between APACHE Π score, alveolar-arterial oxygen difference or PaO 2 /FiO 2 value and time. APACHE Π score 24 h and 72 h after entering ICUs predicted mortality with an area under the ROC curve (AUC) standing respectively at 0.919 and 0.955. Arterial blood lactate clearance rate 12 h, 24 h, 48 h and 72 h after entering ICUs predicted mortality with an area under the ROC curve (AUC) at 0.918, 0.918, 0.909 and 0.991, respectively. Conclusions APACHE Π score applied in combination with arterial blood lactate clearance rate is of clinical significance in assessing the prognosis of ARDS patients.

The rotating propagation of a continuous detonation engine (CDE) with different types of nozzles is investigated in three-dimensional numerical simulation using a one-step chemical reaction model. Flux terms are solved by the so-called monotonicity-preserving weighted essentially non-oscillatory (MPWENO) scheme. The simulated flow field agrees well with the previous experimental results. Once the initial transient effects die down, the detonation wave maintains continuous oscillatory propagation in the annular chamber as long as fuel is continuously injected. Using a numerical flow field, the propulsion performance of a CDE is computed for four types of nozzles, namely the constant-area nozzle, Laval nozzle, diverging nozzle and converging nozzle. The gross specific impulse of the CDE ranges 1 540-1 750 s and the mass flux per square meter ranges 313-330 kg/(m2·s) for different nozzles. Among these four types of nozzles, Laval nozzle performs the best, and these parameters are 1 800 N, 1 750 s and 313 kg/(m2·s). A nozzle can greatly improve the propulsion performance.