Photodetectors Based on ZrS3/MoS2 Heterostructures.

High-performance photodetectors with the detection capability of linearly polarized light have broad applications in both military and civilian fields. Quasi-one-dimensional ZrS3 as an emerging anisotropic two-dimensional material has come under the spotlight owing to its intriguing properties. However, the performance of the ZrS3 photodetector is seriously restricted by its low responsivity. Herein, a novel high-performance photodetector based on the van der Waals ZrS3/MoS2 heterostructure is proposed. Attributed to the charge trapping-assisted photogating effect, interlayer carrier transitions, and fast spatial separation of the photogenerated electron-hole pairs, the device displays superior photoresponse characteristics ranging from the ultraviolet to the visible spectrum in terms of high responsivity up to 212 A/W, an extraordinary external quantum efficiency of 8.5 × 104%, and a prompt rise/decay time of 0.19/0.38 ms. In addition, owing to the profound birefringence and dichroism effects in ZrS3 together with strong light-matter interactions in the heterostructure, profound linear-polarization sensitivity is demonstrated with a dichroic ratio of about 2.8. Overall, this photodetector not only is integrated with the excellent properties of ZrS3 and monolayer MoS2 but also further enhances the advantages through interlayer couplings, which demonstrate the strong potential of the ZrS3-based devices for high-performance, ultrafast, and polarization-sensitive photodetection.

Epidemiological characteristics and quarantine assessment of imported international COVID-19 cases, March to December 2020, Chengdu, China.

International flights have accelerated the global spread of Coronavirus Disease 2019 (COVID-19). Determination of the optimal quarantine period for international travelers is crucial to prevent the local spread caused by imported COVID-19 cases. We performed a retrospective epidemiological study using 491 imported COVID-19 cases in Chengdu, China, to describe the characteristic of the cases and estimate the time from arrival to confirmation for international travelers using nonparametric survival methods. Among the 491 imported COVID-19 cases, 194 (39.5%) were asymptomatic infections. The mean age was 35.6 years (SD = 12.1 years) and 83.3% were men. The majority (74.1%) were screened positive for SARS-CoV-2, conducted by Chengdu Customs District, the People's Republic of China. Asymptomatic cases were younger than presymptomatic or symptomatic cases (P < 0.01). The daily number of imported COVID-19 cases displayed jagged changes. 95% of COVID-19 cases were confirmed by PT-PCR within 14 days (95% CI 13-15) after arriving in Chengdu. A 14-day quarantine measure can ensure non-infection among international travelers with a 95% probability. Policymakers may consider an extension of the quarantine period to minimize the negative consequences of the COVID-19 confinement and prevent the international spread of COVID-19. Nevertheless, the government should consider the balance between COVID-19 and socioeconomic development, which may cause more serious social and health crises.

Ultrafast and Polarization-Sensitive ReS2/ReSe2 Heterostructure Photodetectors with Ambipolar Photoresponse.

Recently, two-dimensional (2D) van der Waals (vdWs) heterostructures provided excellent and fascinating platforms for advanced engineering in high-performance optoelectronic devices. Herein, novel ReS2/ReSe2 heterojunction phototransistors are constructed and explored systematically that display high responsivity, wavelength-dependent ambipolar photoresponse (negative and positive), ultrafast and polarization-sensitive detection capability. This photodetector exhibits a positive photoresponse from UV to visible spectrum (760 nm) with high photoresponsivities about 126.56 and 16.24 A/W under 350 and 638 nm light illumination, respectively, with a negative photoresponse over 760 nm, which is mainly ascribed to the ambipolar photoresponse modulated by gate voltage. In addition, profound linear polarization sensitivity is demonstrated with a dichroic ratio of about ∼1.2 at 638 nm and up to ∼2.0 at 980 nm, primarily owing to the wavelength-dependent absorption anisotropy and the stagger alignment of the crystal. Beyond static photodetection, the dynamic photoresponse of this vdWs device presents an ultrafast and repeatable photoswitching performance with a cutoff frequency (f3dB) exceeding 100 kHz. Overall, this study reveals the great potential of 2D ReX2-based vdWs heterostructures for high-performance, ultrafast, and polarization-sensitive broadband photodetectors.

Prevalence of probable posttraumatic stress disorder and determination of its relationship with everyday functioning in children and adolescents by using generalized estimating equations.

INTRODUCTION: We investigated the prevalence rates for probable PTSD and used generalized estimating equations to identify risk factors for probable PTSD in children and adolescents exposed to the Lushan earthquake. METHODS: A total of 1623 participants completed 3 assessments, including the Children's Revised Impact of Event Scale, at 2 weeks, 3, and 6 months after experiencing the Lushan earthquake. Additionally, demographic variables and variables related to everyday functioning were evaluated at 2 weeks after the earthquake via a self-constructed questionnaire. RESULTS: The percentages of children and adolescents who changed from having no PTSD to probable PTSD and probable PTSD to no PTSD at each time point were approximately 8% and 20% of the sample, respectively. The percentage of participants without PTSD increased from 41.1% at the 2-week to 3-month time point to 54.3% at the 3-month to 6-month time point, and the percentage with persistent probable PTSD decreased from 29.6% to 16.4% at the 2 time points, respectively. Female gender, a sedentary lifestyle, and actively helping others were significant risk factors for probable PTSD, whereas initiating communications with others, actively playing with classmates and friends, and the ability to concentrate on academic studies after resuming class were factors that helped protect against probable PTSD. DISCUSSION: Resistance to PTSD and persistent PTSD symptoms were both common occurrences in child and adolescent survivors. Specific variables related to everyday functioning may be risk factors for probable PTSD. These findings have implications for agencies that provide mental health services after an earthquake.

Comparison of dual influenza and pneumococcal polysaccharide vaccination with influenza vaccination alone for preventing pneumonia and reducing mortality among the elderly: A meta-analysis.

The purpose of this study was to perform a meta-analysis comparing the effectiveness of influenza vaccination alone versus influenza plus pneumococcal dual vaccination for the prevention of pneumonia and mortality in adults ≥ 65 years of age. Medline, Cochrane, CENTRAL, EMBASE, and Google Scholar databases were searched. Inclusion criteria were: 1) Randomized controlled trials (RCTs), 2-arm prospective studies, or retrospective cohort studies; 2) Patients were ≥ 65 years of age with or without chronic respiratory disease; 3) Patients received the influenza vaccine alone or dual pneumococcal and influenza vaccination; 4) Results included incidence of recurrent respiratory tract infections, length of hospital stay, and overall mortality rate. The outcomes were pneumonia and all-cause mortality rates. Of 142 studies identified in the database searches, 6 were ultimately included in the systematic review, and 5 were included in meta-analysis. The number of patients that received the influenza vaccination alone ranged from 211 to 29,346 (total = 53,107), and the number that received influenza+pneumococcal vaccination ranged from 246 to 72,107 (total = 102,068). Influenza+pneumococcal vaccination was associated with a significantly lower pneumonia rate than influenza vaccination alone (relative risk [RR] = 0.835, 95% confidence interval [CI]: 0.718-0.971, P = 0.019), and with a significantly lower all-cause mortality rate than influenza vaccination alone (relative risk [RR] = 0.771, 95% confidence interval [CI]: 0.707-0.842, P = 0.001). In conclusion, the results of this study support concomitant pneumococcal and influenza vaccination of the elderly as a dual vaccination strategy is associated with lower pneumonia and all-cause mortality rates.

Prevalence and risk factors of posttraumatic stress disorder among teachers 3 months after the Lushan earthquake: A cross-sectional study.

Teachers and students often suffer from the same disaster. The prevalence of PTSD in students has been given great attention. However, in acting as mentors to students and their families, teachers are more likely to have vicarious and indirect exposure via hearing stories of their aftermath and witnessing the consequences of traumatic events. There are limited data pertaining to the prevalence of PTSD and its risk factors among teachers. A total of 316 teachers from 21 primary and secondary schools in Baoxing County were administered a project-developed questionnaire which included the items regarding demographic characteristics, earthquake-related experiences, somatic discomforts, emotional reactions, support status, and everyday functioning 2 weeks after the Lushan earthquake, and they finished a 1-to-1 telephone interview for addressing the PTSD criteria of the Mini International Neuropsychiatric Interview (MINI) 3 months after the earthquake. The prevalence of PTSD was 24.4% among teachers. Somatic discomforts (odds ratio [OR] 1.89, 95% confidence interval [CI] 1.06-3.37) were positive risk factors of PTSD. Perceived social support (OR 0.30, 95% CI 0.14-0.62) and being able to calm down (OR 0.25, 95% CI 0.09-0.75) in teaching were negative risk factors. PTSD is commonly seen among teachers after an earthquake, and risk factors of PTSD were identified. These findings may help those providing psychological health programs to find the teachers who are at high risk of PTSD in schools after an earthquake in China.

Prevalence and Predictors of Somatic Symptoms among Child and Adolescents with Probable Posttraumatic Stress Disorder: A Cross-Sectional Study Conducted in 21 Primary and Secondary Schools after an Earthquake.

PURPOSE: To explore the prevalence rates and predictors of somatic symptoms among child and adolescent survivors with probable posttraumatic stress disorder (PTSD) after an earthquake. METHODS: A total of 3053 students from 21 primary and secondary schools in Baoxing County were administered the Patient Health Questionnaire-13 (PHQ-13), a short version of PHQ-15 without the two items about sexuality and menstruation, the Children's Revised Impact of Event Scale (CRIES), and the self-made Earthquake-Related Experience Questionnaire 3 months after the Lushan earthquake. RESULTS: Among child and adolescent survivors, the prevalence rates of all somatic symptoms were higher in the probable PTSD group compared with the controls. The most frequent somatic symptoms were trouble sleeping (83.2%), feeling tired or having low energy (74.4%), stomach pain (63.2%), dizziness (58.1%), and headache (57.7%) in the probable PTSD group. Older age, having lost family members, having witnessed someone get seriously injured, and having witnessed someone get buried were predictors for somatic symptoms among child and adolescent survivors with probable PTSD. CONCLUSIONS: Somatic symptoms among child and adolescent earthquake survivors with probable PTSD in schools were common, and predictors of these somatic symptoms were identified. These findings may help those providing psychological health programs to find the child and adolescent students with probable PTSD who are at high risk of somatic symptoms in schools after an earthquake in China.

Posttraumatic stress disorder and somatic symptoms among child and adolescent survivors following the Lushan earthquake in China: A six-month longitudinal study.

OBJECTIVE: To explore somatic conditions in a sample of 2299 child and adolescent survivors of an earthquake and their relationship to posttraumatic stress disorder (PTSD) symptoms. METHODS: The Children's Revised Impact of Event Scale, the Patient Health Questionnaire (PHQ)-13 scale, a short version of PHQ-15 scale that omits two items involving sexual pain/problems and menstrual problems, and a project-developed questionnaire were administered to participants three and six months after the earthquake. RESULTS: Among child and adolescent survivors, the prevalence rates of probable PTSD were 37.4 and 24.2% three and six months, respectively, after the earthquake. The most common somatic symptoms were trouble sleeping (58.4 and 48.4%), feeling tired or having low energy (52.0 and 46.1%), and stomach pain (45.8 and 45.4%) after three and six months, respectively. Several specific somatic symptoms evaluated three months after the earthquake including trouble sleeping, headache, and shortness of breath were predictors of the overall PTSD symptoms evaluated six months after the earthquake. Additionally, the symptom of hyperarousal evaluated after three months could predict the overall somatic symptoms evaluated after six months. CONCLUSIONS: PTSD and somatic symptoms were common after the earthquake, and a longitudinal association between PTSD and somatic symptoms was detected among child and adolescent survivors. These findings have implications in China and possibly elsewhere.

[Strategic framework for cholera prevention and control in Chengdu: construction and effectiveness evaluation].

OBJECTIVE: To construct an operable strategic framework for cholera prevention and control which mobilized the advantages of local resources and adapted to social developments in Chengdu, and to evaluate its application effects. METHODS: (1) After analyzing the local epidemic data of cholera in Chengdu from 1994 to 2004, we determined the main problems of cholera prevention and control works as well as the efficiency and deficiency of employed measures, and then formed a basic strategic framework. (2) After 55 invited experts preliminarily scored the strategic framework, we selected 72 specific measures to establish a measure entry database, and then the importance and operability of each measure were scored by 17 core experts. (3) Finally, the effectiveness of this strategic framework was evaluated according to the analyzing results of infection control, health education and etiological monitoring. RESULTS: (1) The framework took government leadership as main scenario and the informatization as subordination scenario. Meanwhile, it focused on three points: the improvement of social environment, the completion of system and mechanisms for monitoring and early warning, and the enhancement of CDC response to public health emergencies. Total importance score and operability score of 35 specific measures included in this framework was 4.20 ± 0.86 and 4.09 ± 0.87, respectively. (2) Chengdu had maintained zero cholera incidence for five consecutive years from 2005 to 2009 since it gradually began to implement the strategic framework in 2002. There were 19 positive cholera cases detected by etiological monitoring and all of them were seafood or fishery products including soft-shelled turtles, silver carps and bullfrogs. The coverage rate and qualification rate of the training for grassroots cadres, grassroots medical workers, mobile cooks and their assistants was 98.14% (198 452/202 220) and 98.17% (194 820/198 452) in average, respectively. The qualification rate of the training for employees in food industry was over 96.00% (912 470/950 489). The average awareness rate of cholera prevention and cure knowledge in rural residents, grassroots cadres, grassroots medical workers, mobile cooks and their assistants was 93.87% (1653/1761) and the average formation rate of good hygiene habits was 70.58% (1243/1761). CONCLUSION: A strategic framework suitable for cholera prevention and control in Chengdu has been successfully established in this study. The incidence rate of cholera has maintained zero in Chengdu for five consecutive years under incessant threatening conditions such as the occurrence of cholera cases from time to time in its surrounding areas and the continuous existence of Bacillus comma in seafood or fishery products that entered local markets. Therefore, it demonstrated a good application effects.

Thorombolytic therapy with rescue percutaneous coronary intervention versus primary percutaneous coronary intervention in patients with acute myocardial infarction: a multicenter randomized clinical trial.

BACKGROUND: Although thrombolytic therapy with rescue percutaneous coronary intervention (PCI) is a common treatment strategy for ST-segment elevation acute myocardial infarction (STEMI), scant data are available on its efficacy relative to primary PCI, and comparison was therefore the aim of this study. METHODS: This multicenter, open-label, randomized, parallel trial was conducted in 12 hospitals on patients (age < or = 70 years) with STEMI who presented within 12 hours of symptom onset (mean interval > 3 hours). Patients were randomized to three groups: primary PCI group (n = 101); recombinant staphylokinase (r-Sak) group (n = 104); and recombinant tissue-type plasminogen activator (rt-PA) group (n = 106). For all patients allocated to the thrombolytic therapy arm, coronary angiography was performed at 90 minutes after drug therapy to confirm infarct-related artery (IRA) patency; rescue PCI was performed in cases with TIMI flow grade < or = 2. Bare-metal stent implantation was planned for all patients. RESULTS: After randomization it required an average of 113.4 minutes to start thrombolytic therapy (door-to-needle time) and 141.2 minutes to perform first balloon inflation in the IRA (door to balloon time). Rates of IRA patency (TIMI flow grade 2 or 3) and TIMI flow grade 3 were significantly lower in the thrombolysis group at 90 minutes after drug therapy than in the primary PCI group at the end of the procedure (70.5% vs. 98.0%, P < 0.0001, and 53.0% vs. 85.9%, P < 0.0001, respectively). Rescue PCI with stenting was performed in 117 patients (55.7%) in the thrombolytic therapy arm. Rates of patency and TIMI flow grade 3 were still significantly lower in the rescue PCI than in the primary PCI group (88.9% vs. 97.9%, P = 0.0222, and 68.4% vs. 85.0%, P = 0.0190, respectively). At 30 days post-therapy, mortality rate was significantly higher in the thrombolysis combined with rescue PCI group than in primary PCI group (7.1% vs. 0, P = 0.0034). Rates of death/MI and bleeding complications were significantly higher in the thrombolysis with rescue PCI group than in the primary PCI group (10.0% vs. 1.0%, P = 0.0380, and 28.10% vs. 8.91%, P = 0.0001, respectively). CONCLUSIONS: Thrombolytic therapy with rescue PCI was associated with significantly lower rates of coronary patency and TIMI flow grade 3, but with significantly higher rates of mortality, death/MI and hemorrhagic complications at 30 days, as compared with primary PCI in this group of Chinese STEMI patients with late presentation and delayed treatments.

[A survey of sanitary working status 20 days after the earthquake in Dujiangyan municipality].

OBJECTIVE: To investigate the sanitary working status in the districts for locating residents after earthquake in Dujiangyan municipality. METHODS: Some immediate measures were taken after the earthquake including water source surveillance, restoring immunization system and epidemic surveillance. A questionnaire survey was also conducted to collect information in 107 locating districts of 18 towns. RESULTS: Generally, the sanitary working status was good. Temporary sheds in most districts were Tents (75.70%, 81/107) and simple sheds (19.63%, 21/107), and 69.16% (74/107) districts could use water supply and 94.39% (101/107) arrange specialized persons to disinfect the environment and kill pests. The fly density was 2 per eye-view. The proportions for the correct responds to health knowledge, action adopted and attitude of residents were all above 90%. According to the epidemic surveillance system and mobile syndrome surveillance system in disaster area, there was no increasing trend for the incidences of contagious diseases. CONCLUSION: 20 days after earthquake, the whole situation of disease prevention in disaster area is stable.