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This work demonstrates how to set efficiency benchmarks in photo-electrochemical measurements for solar water splitting with assistance of voltage biases. We modify the applied bias photon-to-current efficiency to circumvent the existing limitations for precisely estimating the energy transformation efficiency under valid conditions. The light sources, surface area of counter electrodes, and oxygen content in electrolytes, and photo-anode materials are changed to investigate their impact on the energy transformation efficiency. This work clarifies that a larger counter electrode surface area results in the enhancement of the oxygen reduction reaction, reducing the applied bias voltage but also reducing the hydrogen generation rate. Furthermore, positive potential biases on the photo-anode and removal of dissolved oxygen molecules in the electrolyte are effective to promote the hydrogen generation rate because of efficient electron/hole separation and the ORR elimination. Due to the high photocurrent generated by the ultraviolet light source, the consumption of photocurrents by the ORR is generally negligible. Therefore, a balance between photocurrent and applied potential bias on the photo-electrochemical cell is proposed to achieve the desired energy transformation efficiency.

Phase-pure anatase titanium dioxide (A-TiO 2 ) with high thermal stability is synthesized by a microwave-assisted hydrothermal (MAH) method. The samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N 2 adsorption–desorption isotherms, and photoluminescence spectra (PL) analysis. The photo-electrochemical responses are examined via linear sweep voltammetry (LSV), intensity-modulated photocurrent spectroscopy (IMPS), and intensity-modulated photovoltage spectroscopy (IMVS). The photocatalytic activity of TiO 2 nanoparticles (NPs) has been confirmed through the methylene blue (MB) de-colorization under the simulated sunlight. The results show that the as-prepared TiO 2 nanocrystals possess thermal stability for the anatase-to-rutile phase transformation up to 900 °C. The phase-pure A-TiO 2 annealed at 800 °C exhibits a much higher de-colorization rate than the commercially available TiO 2 (Degussa P25) powders. The higher photocatalytic activity of this sample is due to its enhanced crystallinity, leading to a lower rate of electron/hole pair recombination and a larger photocurrent density in comparison with all other samples and P25. The sample annealed at 900 °C shows the highest specific activity on MB de-colorization, demonstrating the importance of thermal stability and crystalline phase.

BackgroundVentilator-associated pneumonia (VAP) is one of the most serious treatment-related infections resulting in high mortalities and costs. Our hospital has implemented bundle care in the intensive care units (ICUs) with special focus on VAP prevention. This is a retrospective study to evaluate its efficacy.MethodsWe implemented a six-item VAP care bundle modified from that of the Institute for Healthcare Improvement at five surgical ICUs (SICUs) in the National Taiwan University Hospital. A multidisciplinary teamwork was involved in this bundle care. This study analyses the SICU utilization, ventilator utilization, and VAP incidence between January 2006 and March 2013 to assess the impact of VAP bundle in a clinical setting.ResultsA total of 28,454 SICU patients were analyzed in this study and patients under the age of 18 were excluded (n = 1329); eventually, 27,125 patients were enrolled, with 12,913 patients from the pre-VAP bundle phase and 14,212 from the post-VAP bundle phase. Patients from the post-VAP phase tended to be older (p = 0.024) and with shorter SICU stay (p = 0.006), and disease severity scores (Therapeutic Intervention Scoring System, Glasgow Coma Scale, and Acute Physiology and Chronic Health Evaluation II score) were lower in the post-VAP bundle phase (p

Summary The National Taiwan University Hospital (NTUH) adopted international guidelines for surveillance and control of healthcare-associated infection (HCAI) in 1981. This report describes the secular trends in HCAI at the NTUH over the past 27 years according to site of infection, aetiological agents and control measures. Clinical and microbiological data were collected by infection prevention and control nurses using a standardised case-record form. Specific control programmes were implemented and/or intensified as needed. Poisson or negative binomial regression analysis was used to quantify time trends of the incidence of HCAI. The annual number of discharges increased from 25 074 to 91 234 with a parallel increase in the Charlson comorbidity index. Active HCAI surveillance and periodic feedback were associated with a marked decrease in surgical site infections from 1981 to 2007 (2.5 vs 0.5 episodes per 100 procedures, P

In order to prevent transmission of hospital-acquired vancomycin-resistant enterococci (VRE), the infection control team (ICT) of the National Taiwan University Hospital (NTUH) introduced practical guidelines from January 1997 to June 2000. All patients at NTUH found to be infected or colonized with VRE were placed in strict contact and cohort isolation. Surveillance cultures were obtained from other patients in close proximity in order to determine any spread of VRE. If identified, these patients were also placed in contact and cohort isolation, and their isolates were subjected to antimicrobial susceptibility testing and molecular typing by pulsed-field gel electrophoresis. During this period, 20 patients were found to have VRE. Based on typing results, there were three occasions where the same VRE strain had spread between index patients and roommates or patients staying in neighbouring rooms. No further spread occurred after applying strict contact isolation for these patients. The hospital-acquired VRE infection rate was around 0.03 to 0.09 per 1000 discharges during the intervention period. After July 2000, however, members of the ICT did not actively monitor or implement any interventions to control VRE. The rate then increased to 0.20 per 1000 discharges in 2001. This study suggests that interventions for the control of VRE, based on the guidelines from the Hospital Infection Control Practice Advisory Committee, are effective for control of VRE spread. Failure to adhere to these guidelines may result in an increase in hospital-acquired VRE.

To determine the distribution and antimicrobial drug resistance in bacterial pathogens causing nosocomial infections, surveillance data on nosocomial infections documented from 1981 to 1999 at National Taiwan University Hospital were analyzed. During this period, 35,580 bacterial pathogens causing nosocomial infections were identified. Candida species increased considerably, ranking first by 1999 in the incidence of pathogens causing all nosocomial infections, followed by Staphylococcus aureus and Pseudomonas aeruginosa. Candida species also increased in importance as bloodstream infection isolates, from 1.0% in 1981-1986 to 16.2% in 1999. The most frequent isolates from urinary tract infections were Candida species (23.6%), followed by Escherichia coli (18.6%) and P. aeruginosa (11.0%). P. aeruginosa remained the most frequent isolates for respiratory tract and surgical site infections in the past 13 years. A remarkable increase in incidence was found in methicillin-resistant S. aureus (from 4.3% in 1981-1986 to 58.9% in 1993-1998), cefotaxime-resistant E. coli (from 0% in 1981-1986 to 6.1% in 1993-1998), and cefotaxime-resistant Klebsiella pneumoniae (from 4.0% in 1981-1986 to 25.8% in 1993-1998). Etiologic shifts in nosocomial infections and an upsurge of antimicrobial resistance among these pathogens, particularly those isolated from intensive care units, are impressive and alarming.

From 7 to 24 March 1997, four patients developed Pseudomonas fluorescens bacteremia at the hospital; one on the oncology ward and the other three in the chemotherapy room. These patients all had underlying malignancies and had the Port-A-Cath (Smiths Industries Medical Systems, Deltec, Inc., St. Paul, Minn.) implants. Three patients had primary bacteremia, and one had Port-A-Cath-related infection. None of these patients had received a blood transfusion before the episodes of bacteremia. All patients recovered: two received antimicrobial agents with in vitro activity against the isolates, and the other two did not have any antibiotic treatment. A total of eight blood isolates were recovered from these patients during the febrile episodes that occurred several minutes after the infusion of chemotherapeutic agents via the Port-A-Cath. These isolates were initially identified as P. fluorescens or Pseudomonas putida (four), Burkholderia ( Ralstonia ) pickettii (three), and a non-glucose-fermenting gram-negative bacillus (one) by routine biochemical methods and the Vitek GNI card. These isolates were later identified as P. fluorescens on the basis of the characteristic cellular fatty acid chromatogram and the results of supplemental biochemical tests. The identification of identical antibiotypes by the E test and the random amplified polymorphic DNA patterns generated by arbitrarily primed PCR of the isolates showed that the outbreak was caused by a single clone of P. fluorescens . Surveillance cultures of the possibly contaminated infusion fluids and disinfectants, which were performed 7 days after recognition of the last infected patient, failed to isolate P. fluorescens . This report of a small outbreak caused by P. fluorescens suggests that timely, accurate identification of unusual nosocomial pathogens is crucial for early initiation of an epidemiological investigation and timely control of an outbreak.

Methicillin-resistant Staphylococcus aureus (MRSA) is a worldwide important pathogen in nosocomial infections. To investigate the extent of the problem in Taiwan, analysis for the period of 1981–1994 was carried out of prospective surveillance data from the National Taiwan University Hospital, a major university teaching hospital in Taiwan. The number of nosocomial MRSA infections increased from five in 1981 to 133 in 1994, and the incidence increased from 0.2 episodes/1000 discharges in 1981 to 2.9 episodes/1000 discharges in 1994. The most common infection site was surgical wounds, which accounted for 26.3% of total 577 episodes of nosocomial MRSA infections during the study period. However, bacteraemia has become more and more common during the past 14 years. MRSA infections occured more frequently in patients stayed in the burn unit and other intensive care units than in the general wards. Other than oxacillin, the resistance rate to many other antibiotics also increased in S. aureus strains causing nosocomial infections in this hospital. Vancomycin remained active to all these S. aureus strains, even until 1994.

Objective The application of extracorporeal membrane oxygenation in adults has been increasing, but infections occurring during extracorporeal membrane oxygenation use are rarely described. Methods We retrospectively analyzed the prospectively collected data on nosocomial infection surveillance of 334 patients aged 16 years or more undergoing their first extracorporeal membrane oxygenation for more than 48 hours at a university hospital from 1996 to 2007 for respiratory (20.4%) and cardiac (79.6%) support. Results During a total of 2559 extracorporeal membrane oxygenation days, 55 episodes of infections occurred in 45 patients (13.5%), including 38 bloodstream (14.85 per 1000 extracorporeal membrane oxygenation days), 6 surgical site, 4 respiratory tract, 3 urinary tract, and 4 other infections. Stenotrophomonas maltophilia (16.7%) and Candida species (14.6%) were the predominant blood isolates. In stepwise logistic regression analysis, longer duration of extracorporeal membrane oxygenation use (odds ratio 1.003; 95% confidence interval, 1.001–1.005; P = . 004), mechanical complications (odds ratio, 4.849; 95% confidence interval, 1.569–14.991; P = . 006), autoimmune disease (odds ratio, 6.997; 95% confidence interval, 1.541–31.766; P = . 012), and venovenous mode (odds ratio, 4.473; 95% confidence interval, 1.001–19.977; P = . 050) were independently associated with a higher risk for infections during extracorporeal membrane oxygenation use. Overall in-hospital mortality was 68.3%, and its independent risk factors included older age (odds ratio, 1.037; 95% confidence interval, 1.021–1.054; P 001), neurologic complications (odds ratio, 51.153; 95% confidence interval, 6.773–386.329; P 001), and vascular complications (odds ratio, 1.922; 95% confidence interval, 1.112–3.320; P 001), but not infections during extracorporeal membrane oxygenation use. Conclusions Bloodstream infection was the most common infection during extracorporeal membrane oxygenation use. Duration of extracorporeal membrane oxygenation, mechanical complications, autoimmune disease, and venovenous mode seemed to be independently associated with infections.