Preparation of Medical Supply for Prehospital Emergencies and Disasters: An Internet-Based Simulation Drill.

Background: Mass casualties caused by natural disasters and man-made events may overwhelm local emergency medical services and healthcare systems. Logistics is essential to a successful emergency medical response. Drills have been used in disaster preparedness to validate plans, policies, procedures, and agreements, and identify resource gaps. The application of the internet to facilitate the conduct of exercise was still limited. This study aimed to investigate the optimal preparation of medical supplies by medical emergency response teams (MERTs) during emergencies and disasters using an internet-based drill. Methods: An internet-based drill based on real-life mass casualty incidents (MCIs) was developed and conducted in Taiwan from June 2017 to July 2018. The drill involved an MCI with 50 events delivered under two scenarios: (1) reduced transfer capacity and well-functioning local healthcare facilities (emergency module); (2) severely reduced transfer capacity and dysfunctional local healthcare facilities (disaster module). For each event, medical supplies commonly prepared by local MERTs in Taiwan were listed in structured questionnaires and participants selected the supplies they would use. Results: Forty-three senior medical emergency responders participated in the survey (responding rate of 47.3%). Resuscitation-related supplies increased from emergency to disaster module (e.g., intubation from 9.1% to 13.9%; dopamine from 3.2% to 5.0%; all p < 0.001). In the subgroup analysis of events with life-threatening injuries, the utilization of resuscitation-related supplies (e.g., intubation from 46.6% to 65.3%; p < 0.001) remained higher in the disaster than in the emergency module. Compared to emergency medical technicians, physicians and nurses are more likely to use intravenous/intramuscular analgesics. Conclusions: The severity of scenarios and the professional background of emergency responders have a different utilization of medical supplies in the simulation drill. The internet-based drill may contribute to optimizing the preparedness of medical response to prehospital emergencies and disasters.

Using a telemedicine-assisted airway model to improve the communication and teamwork of tracheal intubation during the coronavirus disease 2019 pandemic.

INTRODUCTION: Isolated spaces impair communication and teamwork during tracheal intubation (TI) in suspected coronavirus disease 2019 patients. We thus aimed to evaluate the telemedicine-assisted airway model (TAM) to improve communication and teamwork during the pandemic. METHODS: This two-stage prospective study included adult patients intubated in the emergency department of the National Taiwan University Hospital between 1 August 2020 and 31 July 2021. First, we randomised patients receiving TI in the standard setting into the conventional group (Con-G) and the isolation area into the isolation group (Iso-G). We evaluated the obstacles to communication and teamwork in an isolation scenario. Second, we developed the TAM to facilitate communication and teamwork between staff in separate spaces during TI and assigned patients to the TAM group (TAM-G). Communication and teamwork were evaluated using the Team Emergency Assessment Measure (TEAM). Subjective evaluations were conducted using a questionnaire administered to medical staff. RESULTS: Eighty-nine patients were enrolled: 17, 34, and 38 in the Con-G, Iso-G, and TAM-G, respectively. The communication frequency (CF) of the Con-G and Iso-G was the highest and lowest, respectively. The CF of the TAM-G increased and approached that of the Con-G. The overall TEAM score was the highest in the Con-G and the lowest in the Iso-G, while the overall score in the TAM-G was comparable to that of the Con-G. DISCUSSION: The TAM may improve communication and teamwork for TIs without compromising efficacy during the pandemic. This study was registered at ClinicalTrials.gov; registration numbers: NCT04479332 and NCT04591873.

Who Can Be the Standardized Patient in Disaster Medical Full-Scale Exercise, Freshman, or Professional?

Background: Disasters cannot be predicted, so being well-prepared is important before a disaster strike. Good preparation needs constant practice and improvement, and full-scale exercise can provide both. The standardized patients (SPs) in a full-scale exercise to simulate patients are vital because they can provide realistic effects to exercise participants. However, there was no literature about who is capable of being an SP. We investigated the relationship between the SPs' current occupation and previous experience with their fidelity and participants' performance. Methods: Three identically designed full-scale exercises were conducted for three different emergency medical teams (EMTs) with the scenario of post-earthquake mass casualty incidents. Forty SPs were used in each exercise. Exercise objective and detail scenario were told to the SPs before exercise, and mock wound makeup was applied to the SPs. Each SP's occupation and previous experience were recorded before exercise. The SP's previous experience was defined as previous exercise experience and previous disaster medicine education. The SPs' fidelity (SPF) was rated using a 5-point Likert scale (1 = poor and 5 = excellent). The participants' performance (PP) was also rated using a 5-point Likert scale (1 = poor and 5 = excellent) according to the accuracy of each SP's triage result and management. The SPF and the PP were evaluated by clinicians with disaster medicine specialties using the same standard. The relationship between the SPs' occupation and the SPF along with occupation, and the PP were analyzed by analysis of variance (ANOVA). The data of the SPF and the PP in the SP groups divided by previous experience were analyzed by the Student's t -test. Results: The SPs' occupations were medical student, nurse, physician, and members of EMT. There was no significant difference in the SPF and the PP between occupations ( p = 0.382 and 0.416, respectively). Both the experienced and the inexperienced SP groups show no significant difference in the SPF ( p = 0.339). Significantly better PP was noted in the inexperienced SP group ( p < 0.001). Conclusions: The SPs' background does not influence the performance of either SPs or exercise participants. We proposed that the success of using freshmen as SPs in full-scale exercise depends on the pre-exercise design and the SP instruction and training.

Spontaneous cervical epidural hematoma in a patient with end-stage renal disease.

Spontaneous spinal epidural hematoma (SEH) is extremely rare in patients with end-stage renal disease (ESRD). We report a case of a 71-year-old man with ESRD presented with progressive left limb weakness. Magnetic resonance imaging (MRI) revealed spinal cervical SEH involving C3-5 level. The patient received emergent decompression laminectomy with the evacuation of the epidural hematoma.

The Effectiveness of Functional Exercises for Teaching Method Disaster Medicine to Medical Students.

Introduction Functional exercises are effective for testing disaster management training. Previously, we found that functional exercises promote student engagement and improve the perception of learning after exercise. Objective The study objective is to investigate whether functional exercise is effective for teaching disaster medicine. Methods Students who partook in a two-day course of disaster medicine were recruited. The course consisted of lectures and workshops followed by a half-day functional exercise and was designed based on four core competency domains which included major disaster medicine concepts. After the lectures and workshops, participants completed a test to assess their knowledge of the core competency domains and a questionnaire to evaluate their willingness to pursue further training and participate in a disaster medical assistance team (DMAT) and their interest in disaster exercises. The functional exercise involved the scenario of an earthquake and mass-casualty incident and participants acted as DMAT members in the exercise. A post-exercise debrief was conducted by the evaluators to discuss performance and evaluate the results of the exercise. Participants then completed the same tests and questionnaires as before the exercise. Results Ninety-seven students were recruited, 72 of which were medical students. Pre- and post-exercise tests and questionnaires were completed by 48. We found disaster scene safety knowledge to be significantly improved after the functional exercise. Students' willingness for further training and participation in a DMAT as well as their interest in disaster training was high before and after the exercise. Conclusion Disaster scene safety is a vital element of disaster medicine training but it is difficult to teach. Functional exercises represent a good tool for this purpose and can maintain enthusiasm for learning and participating in disaster medicine-related activities.

Seroprevalence Surveys for Anti-SARS-CoV-2 Antibody in Different Populations in Taiwan With Low Incidence of COVID-19 in 2020 and Severe Outbreaks of SARS in 2003.

Accurate detection of anti-SARS-CoV-2 antibodies provides a more accurate estimation of incident cases, epidemic dynamics, and risk of community transmission. We conducted a cross-sectional seroprevalence study specifically targeting different populations to examine the performance of pandemic control in Taiwan: symptomatic patients with epidemiological risk and negative qRT-PCR test (Group P), frontline healthcare workers (Group H), healthy adult citizens (Group C), and participants with prior virologically-confirmed severe acute respiratory syndrome (SARS) infection in 2003 (Group S). The presence of anti-SARS-CoV-2 total and IgG antibodies in all participants were determined by Roche Elecsys® Anti-SARS-CoV-2 test and Abbott SARS-CoV-2 IgG assay, respectively. Sera that showed positive results by the two chemiluminescent immunoassays were further tested by three anti-SARS-CoV-2 lateral flow immunoassays and line immunoassay (MIKROGEN recomLine SARS-CoV-2 IgG). Between June 29 and July 25, 2020, sera of 2,115 participates, including 499 Group P participants, 464 Group H participants, 1,142 Group C participants, and 10 Group S participants, were tested. After excluding six false-positive samples, SARS-CoV-2 seroprevalence were 0.4, 0, and 0% in Groups P, H, and C, respectively. Cross-reactivity with SARS-CoV-2 antibodies was observed in 80.0% of recovered SARS participants. Our study showed that rigorous exclusion of false-positive testing results is imperative for an accurate estimate of seroprevalence in countries with previous SARS outbreak and low COVID-19 prevalence. The overall SARS-CoV-2 seroprevalence was extremely low among populations of different exposure risk of contracting SARS-CoV-2 in Taiwan, supporting the importance of integrated countermeasures in containing the spread of SARS-CoV-2 before effective COVID-19 vaccines available.

Multicenter evaluation of four immunoassays for the performance of early diagnosis of COVID-19 and assessment of antibody responses of patients with pneumonia in Taiwan.

BACKGROUND/PURPOSE: Our study goals were to evaluate the diagnostic performance of four anti-SARS-CoV-2 antibodies tests and the differences in dynamic immune responses between COVID-19 patients with and without pneumonia. METHODS: We collected 184 serum samples from 70 consecutively qRT-PCR-confirmed COVID-19 patients at four participating hospitals from 23 January 2020 to 30 September 2020. COVID-19 pneumonia was defined as the presence of new pulmonary infiltration. Serum samples were grouped by the duration after symptom onset on a weekly basis for antibody testing and analysis. The four immunoassays: Beckman SARS-CoV-2 IgG/IgM (Beckman Test), Siemens (ADVIA Centaur®) SARS-CoV-2 Total (COV2T) (Siemens Test), SBC COVID-19 IgG ELISA (SBC Test) and EliA SARS-CoV-2-Sp1 IgG/IgM/IgA P2 Research (EliA Test) were used for detecting the SARS-CoV-2 specific antibodies. RESULTS: The sensitivity of all tests reached 100% after 42 days of symptom onset. Siemens Test, the only test detecting total anti-SARS-CoV-2 antibodies, had the best performance in the early diagnosis of COVID-19 infection (day 0-7: 77%; day 8-14: 95%) compared to the other 3 serological tests. All tests showed 100% specificity except SBC Test (98%). COVID-19 patients with pneumonia had significantly higher testing signal values than patients without pneumonia (all p values < 0.05, except EliA IgM Test). However, Siemens Test and SBC Test had highest probability in early prediction of the presence of COVID-19 pneumonia. CONCLUSION: Chronological analysis of immune response among COVID-19 patients with different serological tests provides important information in the early diagnosis of SARS-CoV-2 infection and prediction of the risk of pneumonia after infection.

Multicenter evaluation of two chemiluminescence and three lateral flow immunoassays for the diagnosis of COVID-19 and assessment of antibody dynamic responses to SARS-CoV-2 in Taiwan.

This multicenter, retrospective study included 346 serum samples from 74 patients with coronavirus disease 2019 (COVID-19) and 194 serum samples from non-COVID-19 patients to evaluate the performance of five anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody tests, i.e. two chemiluminescence immunoassays (CLIAs): Roche Elecsys® Anti-SARS-CoV-2 Test (Roche Test) and Abbott SARS-CoV-2 IgG (Abbott Test), and three lateral flow immunoassays (LFIAs): Wondfo SARS-CoV-2 Antibody Test (Wondfo Test), ASK COVID-19 IgG/IgM Rapid Test (ASK Test), and Dynamiker 2019-nCoV IgG/IgM Rapid Test (Dynamiker Test). We found high diagnostic sensitivities (%, 95% confidence interval [CI]) for the Roche Test (97.4%, 93.4-99.0%), Abbott Test (94.0%, 89.1-96.8%), Wondfo Test (91.4%, 85.8-94.9%), ASK Test (97.4%, 93.4-99.0%), and Dynamiker Test (90.1%, 84.3-94.0%) after >21 days of symptom onset. Meanwhile, the diagnostic specificity was 99.0% (95% CI, 96.3-99.7%) for the Roche Test, 97.9% (95% CI, 94.8-99.2%) for the Abbott Test, and 100.0% (95% CI, 98.1-100.0%) for the three LFIAs. Cross-reactivity was observed in sera containing anti-cytomegalovirus (CMV) IgG/IgM antibodies and autoantibodies. No difference was observed in the time to seroconversion detection of the five serological tests. Specimens from patients with COVID-19 pneumonia demonstrated a shorter seroconversion time and higher chemiluminescent signal than those without pneumonia. Our data suggested that understanding the dynamic antibody response after COVID-19 infection and performance characteristics of different serological test are crucial for the appropriate interpretation of serological test result for the diagnosis and risk assessment of patient with COVID-19 infection.

Four point-of-care lateral flow immunoassays for diagnosis of COVID-19 and for assessing dynamics of antibody responses to SARS-CoV-2.

OBJECTIVES: We aimed to evaluate the role of rapid serological tests in the management of coronavirus disease 2019 (COVID-19) patients. METHODS: This retrospective study enrolled 16 real-time reverse transcription polymerase chain reaction-confirmed symptomatic patients with COVID-19 and 58 COVID-19 negative patients at a medical center in Taiwan over a 3-month period. Serial serum samples were collected and tested for antibody response using four point-of-care (POC) lateral flow immunoassays (LFIA) (ALLTEST 2019-nCoV IgG/IgM Rapid Test, Dynamiker 2019-nCoV IgG/IgM Rapid Test, ASK COVID-19 IgG/IgM Rapid Test, and Wondfo SARS-CoV-2 Antibody Test). Time-dependent detection sensitivity and timeliness of seroconversion were determined and compared between the four POC rapid tests. RESULTS: The overall sensitivity and specificity of the four tests for detecting anti-SARS-CoV-2 antibodies after 3 weeks of symptom onset were 100% and 100%, respectively. There was no significant difference between the rapid tests used for detection of IgM and IgG separately and those used for detection of combined total antibody (mainly IgM/IgG). There was no significant difference between the four POC rapid tests in terms of time required for determining seroconversion of COVID-19. Patients with COVID-19 with pneumonia demonstrated shorter seroconversion time than those without pneumonia. CONCLUSION: Though the POC antibody rapid tests based on LFIA showed reliable performance in the detection of SARS-CoV-2-specific antibodies, the results of these tests should be interpreted and applied appropriately in the context of antibody dynamic of COVID-19 infection. COVID-19 patients complicated with pneumonia exhibited earlier anti-SARS-CoV-2 antibody response than COVID-19 patients without pneumonia.

A Double Triage and Telemedicine Protocol to Optimize Infection Control in an Emergency Department in Taiwan During the COVID-19 Pandemic: Retrospective Feasibility Study.

BACKGROUND: Frontline health care workers, including physicians, are at high risk of contracting coronavirus disease (COVID-19) owing to their exposure to patients suspected of having COVID-19. OBJECTIVE: The aim of this study was to evaluate the benefits and feasibility of a double triage and telemedicine protocol in improving infection control in the emergency department (ED). METHODS: In this retrospective study, we recruited patients aged ≥20 years referred to the ED of the National Taiwan University Hospital between March 1 and April 30, 2020. A double triage and telemedicine protocol was developed to triage suggested COVID-19 cases and minimize health workers' exposure to this disease. We categorized patients attending video interviews into a telemedicine group and patients experiencing face-to-face interviews into a conventional group. A questionnaire was used to assess how patients perceived the quality of the interviews and their communication with physicians as well as perceptions of stress, discrimination, and privacy. Each question was evaluated using a 5-point Likert scale. Physicians' total exposure time and total evaluation time were treated as primary outcomes, and the mean scores of the questions were treated as secondary outcomes. RESULTS: The final sample included 198 patients, including 93 cases (47.0%) in the telemedicine group and 105 cases (53.0%) in the conventional group. The total exposure time in the telemedicine group was significantly shorter than that in the conventional group (4.7 minutes vs 8.9 minutes, P<.001), whereas the total evaluation time in the telemedicine group was significantly longer than that in the conventional group (12.2 minutes vs 8.9 minutes, P<.001). After controlling for potential confounders, the total exposure time in the telemedicine group was 4.6 minutes shorter than that in the conventional group (95% CI -5.7 to -3.5, P<.001), whereas the total evaluation time in the telemedicine group was 2.8 minutes longer than that in the conventional group (95% CI -1.6 to -4.0, P<.001). The mean scores of the patient questionnaire were high in both groups (4.5/5 to 4.7/5 points). CONCLUSIONS: The implementation of the double triage and telemedicine protocol in the ED during the COVID-19 pandemic has high potential to improve infection control.

The Value of Functional Exercise in Pediatric Mass- Casualty Incident Training.

BACKGROUND: Hospital staff in Taiwan practice mass casualty incident (MCI) management through full-scale exercise (FSE). However, FSE is generally resource-intensive and time-consuming. As an alternative, functional exercise (FE) may be more cost-effective with a similar effect in certain aspects. Hence, we aimed to evaluate the FE value in MCI training. We investigated whether FE can increase the familiarity of pediatric MCI response and the effect in different groups. METHODS: A new emergency operation plan (EOP) of nontraumatic pediatric MCI was developed in 2018 for our Children's Hospital. An FE was conducted to assess the plan. In addition to the emergency department staff, head nurses, supervisors, and physicians of Children's Hospital also participated in the exercise. Pre- and post-exercise questionnaires were designed, and participants were asked to evaluate their familiarity with pediatric MCI response pre- and post-exercise. Participants' reading experience of the new EOP, previous training level, occupation position, and whether they were using a computer during the exercise were also noted in the questionnaires. Data were analyzed using paired t-test and Fisher's exact test. RESULTS: Among 49 participants, 16 participants completed the pre- and post-exercise questionnaires. The post-exercise familiarity score was found to be significantly higher than that of pre-exercise (p < 0.05). There were no significant differences among the relationships between familiarity increase and participants' reading experience of the new EOP, previous training level, occupation position, and whether they were using a computer during the exercise. CONCLUSIONS: FE can significantly increase the familiarity of the hospital staff with pediatric MCI response and may be applied as a new training method of hospital disaster preparedness.

Review of Medical Response in 2015 TransAsia Airways Flight 235 Aircraft Crash.

TransAsia Airways Flight 235 was a domestic flight that crashed into the Keelung River on February 4, 2015, about several minutes after take-off from Taipei Songshan Airport. There were 53 passengers and five crew members on board, however, only 15 of them survived. Twenty-seven casualties were sent to eight nearby hospitals. All of them were sent by ambulances of fire departments. Among 27 casualties, 10 experienced traumatic out-of-hospital cardiac arrest and the remaining 17 had traumatic injuries or hypothermia. The accident revealed several important issues regarding disaster medical response in Taiwan. First, compared to previous aircraft crash accidents in Taiwan, the search and rescue process was much more difficult because the airplane had fallen into the middle of a river. It was much more like a river rescue than an aircraft crash. Responders could not reach the casualties and provide care initially due to lack of proper equipment needed to cross the river. Second, the airplane crashed right on the border between two cities, the "command and communication" issue was also confused in the beginning. Third, the role of the disaster medical assistant team (DMAT) in Taiwan should be re-evaluated, including various protocols and standard procedures for dispatch, task, cooperation, staff training and logistics. By reviewing the response, we hope we can improve our system for the challenges in the future.

Challenges of Burn Mass Casualty Incidents in the Prehospital Setting: Lessons From the Formosa Fun Coast Park Color Party.

Objective: A burn mass casualty incident (BMCI) involving 499 patients occurred at a "color party" in Taiwan in June 27, 2015. We implemented a study to identify critical challenges regarding the prehospital emergency care in BMCIs. Methods: A 3-stage, mixed methods study was conducted in 2016. First, a statistical analysis of prehospital management using the data retrieved from the Emergency Medical Management System of the Ministry of Health and Welfare, Taiwan was performed. This was followed by a face-to-face, open-ended interview with the emergency medical technicians and the staff of the emergency operations center who responded to the incident; and the transcription of the interview data into constructed themes. Results: Our study indicated that the signs of inhalation injury needed to be incorporated in the field triage protocol for BMCIs; the collaborative utilization of regional emergency medical services may improve the surge capacity in the field; and an "island-hopping" strategy for patient transportation may allow the healthcare systems to manage the surge of burn patients more efficiently. Conclusions: Current field triage protocols may be insufficient for burn patients and should be further investigated. The practices in field triage, transport capacity, and transfer strategy can be considered as a part of an efficient prehospital emergency response to BMCIs.

Density-functional calculations of the conversion of methane to methanol on platinum-decorated sheets of graphene oxide.

By means of calculations based on density-functional theory (DFT), we have investigated the conversion of methane on two platinum atoms supported with a graphene-oxide sheet (Pt2/GO). In our calculations, a CH4 molecule can be adsorbed around the Pt atoms of the Pt2/GO sheet with adsorption energies within -0.11 to -0.53 eV; an elongated C-H bond indicates that Pt atoms on that sheet can activate the C-H bond of a CH4 molecule. The role of the GO sheet in the activation of CH4 was identified according to an analysis of the electronic density: the GO sheet induces the d-band of Pt atoms to generate several specific dz(2) state features above the Fermi level, which enabled the activation of the C-H bond of CH4 in generating an evident area of overlap with the hydrogen s orbital of the C-H bond. Upon a dioxygen molecule being added onto the Pt2/GO sheet, this molecule can react with activated CH4 according to mechanisms of form 2CH4 + O2 [Pt2/GO]--> 2CH3OH, and restore the original Pt2/GO sheet.

Bystander-initiated CPR in an Asian metropolitan: does the socioeconomic status matter?

OBJECTIVES: To determine the association of neighborhood socioeconomic status (SES) with bystander-initiated cardiopulmonary resuscitation (CPR) and patient outcomes of out of hospital cardiac arrests (OHCAs) in an Asian metropolitan area. METHODS: We performed a retrospective study in a prospectively collected cohort from the Utstein registry of adult non-traumatic OHCAs in Taipei, Taiwan. Average real estate value was assessed as the first proxy of SES. Twelve administrative districts in Taipei City were categorized into low versus high SES areas to test the association. The primary outcome was bystander-initiated CPR, and the secondary outcome was patient survival status. Factors associated with bystander-initiated CPR were adjusted for in multivariate analysis. The mean household income was assessed as the second proxy of SES to validate the association. RESULTS: From January 1, 2008 to December 30, 2009, 3573 OHCAs received prehospital resuscitation in the community. Among these, 617 (17.3%) cases received bystander CPR. The proportion of bystander CPR in low-SES vs. high-SES areas was 14.5% vs. 19.6% (p<0.01). Odds ratio of receiving bystander-initiated CPR in low-SES areas was 0.72 (95% confidence interval: [0.60-0.88]) after adjusting for age, gender, witnessed status, public collapse, and OHCA unrecognized by the online dispatcher. Survival to discharge rate was significantly lower in low-SES areas vs. high-SES areas (4.3% vs. 6.8%; p<0.01). All results above remained consistent in the analyses by mean household income. CONCLUSIONS: Patients who experienced an OHCA in low-SES areas were less likely to receive bystander-initiated CPR, and demonstrated worse survival outcomes.

The effect of tropical cyclones (typhoons) on emergency department visits.

BACKGROUND: Case reports have indicated that a tropical cyclone may increase Emergency Department (ED) visits significantly. STUDY OBJECTIVES: To examine emergency health care demands across a series of tropical cyclones, and to build a predictive model to analyze a cyclone's potential effect. METHODS: This was an observational non-concurrent prospective study performed in Taiwan. Twenty hospitals were included. The number of daily ED visits in each hospital was our primary end point, and data were retrieved from the database provided by the National Health Insurance Research Database. Our study examined the period from 2000 to 2008. A total of 22 tropical cyclones (typhoons) that had passed over eastern Taiwan and covered the area under study were included. Multiple linear regression time-series models were employed to estimate the effects of "days since typhoon landfall" and various characteristics of the typhoons on the end point of daily ED visits to each hospital. RESULTS: The final multiple linear regression time-series model showed that the number of daily ED visits increased in areas where a strong typhoon had landed directly, with the increase being evident during the first 2 days since landfall. Our model also indicated that the three most important variables to predict a change in the pattern of daily ED visits were intensity of typhoon, simultaneous heavy rain, and direct landfall. CONCLUSIONS: During tropical cyclones, emergency services were under increased demand in selected time periods and areas. Health care authorities should collect information to build local models to optimize their resources allocation in preparation.

Surface oxide effect on optical sensing and photoelectric conversion of α-In2Se3 hexagonal microplates.

The surface formation oxide assists of visible to ultraviolet photoelectric conversion in α-In2Se3 hexagonal microplates has been explored. Hexagonal α-In2Se3 microplates with the sizes of 10s to 100s of micrometers were synthesized and prepared by the chemical vapor transport method using ICl3 as a transport agent. Many vacancies and surface imperfection states have been found in the bulk and on the surface of the microplate because of the intrinsic defect nature of α-In2Se3. To discover physical and chemical properties and finding technological uses of α-In2Se3, several experiments including transmission electron miscopy (TEM), X-ray photoelectron spectroscopy (XPS), surface photovoltage (SPV), photoluminescence (PL), surface photoresponse (SPR), photoconductivity (PC), and thermoreflectance (TR) measurements have been carried out. Experimental results of TEM, XPS, SPV, PL, and SPR measurements show that a surface oxidation layer α-In2Se3-3xO3x (0 ≤ x ≤ 1) has formed on the crystal face of α-In2Se3 in environmental air with the inner layer content close to In2Se3 but the outermost layer content approaching In2O3. The near band edge transitions of α-In2Se3 microplates have been probed experimentally by TR and PC measurements. The direct band gap of α-In2Se3 has been determined to be 1.453 eV. The SPV result shows a maximum quantum efficiency of the surface oxide α-In2Se3-3xO3x (0 ≤ x ≤ 1) that presents a peak photoresponse near 2.18 eV. The analyses of SPV, SPR, PL, TR, and PC measurements revealed that the surface oxide layer facilitates the conversion of the ultraviolet to the visible range while the native defects (Se and In vacancies) sustain photoconductivity in the near-infrared region. On the basis of the experimental results a wide-energy-range photodetector that combines PC- and SPR-mode operations for α-In2Se3 microplate has been made. The testing results show a well-behaved function of photoelectric conversion in the near-infrared to ultraviolet region via the auxiliary forming of surface oxide on the crystalline face of the α-In2Se3 microplates.

Impact of liver cirrhosis on mortality in patients with community-acquired bacteremia.

Few studies have analyzed the impact of liver cirrhosis, a clinically significant comorbid medical condition, on the mortality of patients with community-acquired bacteremia. We conducted an observational study of 839 consecutive community-acquired bacteremia patients who were hospitalized through the emergency department (ED). We compared the 30-day mortality of bacteremia patients with and without liver cirrhosis using Cox proportional hazards regression. The probability of survival at day 30 was significantly different for the cirrhotic and noncirrhotic groups (53% versus 82%, respectively; P < 0.001 by the log-rank test). Multivariate analysis indicated that liver cirrhosis was associated with an increased risk of short-term mortality (hazard ratio, 2.0; 95% confidence interval, 1.1-3.5), as well as age, higher comorbidity index, and markers obtained from clinical presentation at ED. In conclusion, in addition to the effects from other prognostic factors, liver cirrhosis has a significant impact on the mortality of patients with community-acquired bacteremia.