Highly efficient photocatalytic z-scheme hydrogen production over oxygen-deficient WO3-x nanorods supported Zn0.3Cd0.7S heterostructure

The demand for clean renewable energy is increasing due to depleting fossil fuels and environmental concerns. Photocatalytic hydrogen production through water splitting is one such promising route to meet global energy demands with carbon free technology. Alternative photocatalysts avoiding noble metals are highly demanded. Herein, we fabricated heterostructure consist of oxygen-deficient WO3-x nanorods with Zn0.3Cd0.7S nanoparticles for an efficient Z-Scheme photocatalytic system. Our as obtained heterostructure showed photocatalytic H2 evolution rate of 352.1 ?mol h-1 with apparent quantum efficiency (AQY) of 7.3% at ? = 420 nm. The photocatalytic hydrogen production reaches up to 1746.8 ?mol after 5 hours process in repeatable manner. The UV-Visible diffuse reflectance spectra show strong absorption in the visible region which greatly favors the photocatalytic performance. Moreover, the efficient charge separation suggested by electrochemical impedance spectroscopy and photocurrent response curves exhibit enhancement in H2 evolution rate. The strong interface contact between WO3-x nanorods and Zn0.3Cd0.7S nanoparticles ascertained from HRTEM images also play an important role for the emigration of electron. Our findings provide possibilities for the design and development of new Z-scheme photocatalysts for highly efficient hydrogen production. 1 2017 The Author(s).Scopu

Pan-resistant Acinetobacter infection in neonates in Karachi, Pakistan.

Background: Pan-resistant Acinetobacter infection has emerged as an important nosocomial pathogen in our inPatient neonates over the past few years. Methodology: We performed a retrospective chart review during a five-year period (July 2003 - June 2008) of all neonates hospitalized in our neonatal intensive care unit (NICU) who developed Acinetobacter infection to identify mortality-associated risk factors in Acinetobacter neonatal infection. Results: During the five-year study period, 122 cultures from 78 neonates grew Acinetobacter. Source sites of positive culture were in the following descending order: blood (n = 57), trachea (n = 55), tissue/wound/body fluids (n = 4), eye (n = 4), urine (n = 1), and cerebrospinal fluid (n = 1). Twenty-four (31%) Patients had Acinetobacter isolated from more than one site. At the time of admission the mean age was 2.08 +/- 4 days and mean weight was 1.77 +/- 0.88 kg, 75% were premature. Pan-resistance (87/122, sensitive only to Polymyxin) was present in 71% of Acinetobacter isolates. Crude mortality rate of this cohort was 47%, while 70% of Patients died within four days after positive Acinetobacter culture. We identified weight of less than 1 kg on admission (p 0.06, adjusted Odds Ratio (AOR) 1.53), gestational age 28 weeks or less (p 0.011, AOR 2.88), poor perfusion (p 0.007, AOR 2.4), thrombocytopenia (p 0.01, AOR 1.6) and metabolic acidosis (p 0.01, AOR 1.67) as predictors associated with poor outcome. Conclusion: Pan-resistant Acinetobacter infection is exceedingly fatal in newborns, particularly in premature and very low-birth weight neonates. Rational antibiotic use and vigilant infection control in NICUs are key to controlling multi-drug resistant Acinetobacter infection and improving clinical outcome

Tungsten-molybdenum oxide nanowires/reduced graphene oxide nanocomposite with enhanced and durable performance for electrocatalytic hydrogen evolution reaction.

Hydrogen has attracted huge interest globally as a durable, environmentally safe and renewable fuel. Electrocatalytic hydrogen evolution reaction (HER) is one of the most promising methods for large scale hydrogen production, but the high cost of Pt-based materials which exhibit the highest activity for HER forced researchers to find alternative electro-catalyst. In this study, we report noble metal free a 3D hybrid composite of tungsten-molybdenum oxide and reduced graphene oxide (GO) prepared by a simple one step hydrothermal method for HER. Benefitting from the synergistic effect between tungsten-molybdenum oxide nanowires and reduced graphene oxide, the obtained W-Mo-O/rGO nanocomposite showed excellent electro-catalytic activity for HER with onset potential 50 mV, a Tafel slope of 46 mV decade-1 and a large cathodic current, while the tungsten-molybdenum oxide nanowires itself is not as efficient HER catalyst. Additionally, W-Mo-O/rGO composite also demonstrated good durability up to 2000 cycles in acidic medium. The enhanced and durable hydrogen evolution reaction activity stemmed from the synergistic effect broadens noble metal free catalysts for HER and provides an insight into the design and synthesis of low-cost and environment friendly catalysts in electrochemical hydrogen production

Highly efficient sustainable photocatalytic Z-scheme hydrogen production from an α-Fe2O3 engineered ZnCdS heterostructure

We present an α-Fe2O3/Zn0.4Cd0.6S heterostructure that shows visible light photocatalytic H2 production as high as 536.8μmolh−1 with apparent quantum efficiency of 11.2% at 420nm. The UV–vis diffuse reflectance spectra of as-synthesized α-Fe2O3/Zn0.4Cd0.6S heterostructure reveal efficient absorption in the visible region, which is a key factor in the enhanced catalytic activity. Moreover, the increase in charge separation efficiency of α-Fe2O3/Zn0.4Cd0.6S suggested by electrochemical impedance spectroscopy and photocurrent response also results in enhanced photocatalytic H2 production. The interface contact between α-Fe2O3 and Zn0.4Cd0.6S ascertained from HRTEM images promotes the recombination of photogenerated electrons from the conduction band of α-Fe2O3 and holes from the valence band of Zn0.4Cd0.6S, thus enhancing the utilization of solar light and increasing the efficiency. Our coupling approach to synthesizing an efficient Z-scheme photocatalyst provides insight into the design of further solar energy utilization photocatalysts.- USTC/Anhui Government Scholarships programme - CAS-TWAS President's Fellowship programme. - Qatar National Research Fund (a member of the Qatar Foundation) - grant # NPRP [9—219-2-105]

RSV associated hospitalizations in children in Karachi, Pakistan: Implications for vaccine prevention strategies

Major progress is being made in vaccines against Respiratory Syncytial Virus (RSV), with multiple vaccine candidates currently in the clinical phase of development. Making an investment case for public sector financing of RSV vaccine will require estimation of burden, cost-effectiveness, and impact. The aim of this study is to determine the proportion, age distribution and clinical spectrum of RSV associated hospitalizations in children in Karachi, Pakistan. A three years prospective study was conducted at the Aga Khan University Hospital in Karachi, a city of 20 million in south Pakistan, from August 2009 to June 2012. Children less than five years old admitted with acute respiratory infections (ARI) were enrolled. Throat swabs were collected and tested for RSV using real-time PCR. Multivariable log binomial regression analysis was performed to identify the associated factors of RSV infection. Out of 1150 children enrolled, RSV was detected among 223 (19%). Highest rate of RSV detection was in young infants less than 3 months of age (48/168, 29%), which accounted for 22% of all RSV detected. Most common diagnosis in RSV positive infants (age) was bronchiolitis followed by pneumonia, while in older children between the ages of one and 5 years of age, pneumonia and asthma were the most common diagnosis. Although identified year-round, RSV was most prevalent from August to October with peak in September, coinciding with the rainy season. This study identified RSV to be independently associated with younger age (P = 0.036), rainy season (P \u3c 0.001), post-tussive emesis (P = 0.008), intubation (P = 0.003), and discharge diagnosis of bronchiolitis (P = 0.004). Vaccines against RSV that target this age group are likely to yield remarkable benefit

Enhanced and durable electrocatalytic performance of thin layer PtRu bimetallic alloys on Pd-nanocubes for methanol oxidation reactions.

As a renewable and promising energy devices, direct methanol fuel cells (DMFCs) have attracted a wide range of interest in recent years. The design of electrocatalysts highly influences the performance of DMFCs systems. Herein, PtRu bimetallic alloy nanoparticles have been fabricated onto a Pd nanocube (NC) core material by a facile wet chemical co-precipitation method. Structural and morphological characterization of the catalyst was performed using X-ray photoelectron spectroscopy (XPS) analysis, energy-dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), high-angle annular dark-field scanning TEM (HAADF-STEM) elemental mapping and temperature programmed reduction (TPR). The presence of a single TPR peak strongly supported bimetallic Pt-Ru interactions and alloying. The electrocatalytic performance of the as-synthesized PtRu@Pd-NC catalyst for the methanol oxidation reaction (MOR) is studied in HClO4 aqueous solution by cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS), and it is compared with that of a PtRu/C (E-TEK) catalyst. The catalyst has shown the highest specific activity (ca. 11.44 mA cm(-2) at 0.70 V), a lower onset potential and enhanced durability for MOR, which is significantly higher than the commercial PtRu/C (E-TEK) catalyst and other reported Pt/Pd-based catalysts. The results attribute to mutual interactions of the core-shell material that enhance the chemisorption of methanol

Associations between eight earth observation-derived climate variables and enteropathogen infection: An independent participant data meta-analysis of surveillance studies with broad spectrum nucleic acid diagnostics

Diarrheal disease, still a major cause of childhood illness, is caused by numerous, diverse infectious microorganisms, which are differentially sensitive to environmental conditions. Enteropathogen‐specific impacts of climate remain underexplored. Results from 15 studies that diagnosed enteropathogens in 64,788 stool samples from 20,760 children in 19 countries were combined. Infection status for 10 common enteropathogens—adenovirus, astrovirus, norovirus, rotavirus, sapovirus, Campylobacter, ETEC, Shigella, Cryptosporidium and Giardia—was matched by date with hydrometeorological variables from a global Earth observation dataset—precipitation and runoff volume, humidity, soil moisture, solar radiation, air pressure, temperature, and wind speed. Models were fitted for each pathogen, accounting for lags, nonlinearity, confounders, and threshold effects. Different variables showed complex, non‐linear associations with infection risk varying in magnitude and direction depending on pathogen species. Rotavirus infection decreased markedly following increasing 7‐day average temperatures—a relative risk of 0.76 (95% confidence interval: 0.69–0.85) above 28°C—while ETEC risk increased by almost half, 1.43 (1.36–1.50), in the 20–35°C range. Risk for all pathogens was highest following soil moistures in the upper range. Humidity was associated with increases in bacterial infections and decreases in most viral infections. Several virus species\u27 risk increased following lower‐than‐average rainfall, while rotavirus and ETEC increased with heavier runoff. Temperature, soil moisture, and humidity are particularly influential parameters across all enteropathogens, likely impacting pathogen survival outside the host. Precipitation and runoff have divergent associations with different enteric viruses. These effects may engender shifts in the relative burden of diarrhea‐causing agents as the global climate changes

Pathogen-specific burdens of community diarrhoea in developing countries: A multisite birth cohort study (MAL-ED)

Background: Most studies of the causes of diarrhoea in low-income and middle-income countries have looked at severe disease in people presenting for care, and there are few estimates of pathogen-specific diarrhoea burdens in the community.Methods: We undertook a birth cohort study with not only intensive community surveillance for diarrhoea but also routine collection of non-diarrhoeal stools from eight sites in South America, Africa, and Asia. We enrolled children within 17 days of birth, and diarrhoeal episodes (defined as maternal report of three or more loose stools in 24 h, or one loose stool with visible blood) were identified through twice-weekly home visits by fieldworkers over a follow-up period of 24 months. Non-diarrhoeal stool specimens were also collected for surveillance for months 1-12, 15, 18, 21, and 24. Stools were analysed for a broad range of enteropathogens using culture, enzyme immunoassay, and PCR. We used the adjusted attributable fraction (AF) to estimate pathogen-specific burdens of diarrhoea.|Findings: Between November 26, 2009, and February 25, 2014, we tested 7318 diarrhoeal and 24 310 non-diarrhoeal stools collected from 2145 children aged 0-24 months. Pathogen detection was common in non-diarrhoeal stools but was higher with diarrhoea. Norovirus GII (AF 5·2%, 95% CI 3·0-7·1), rotavirus (4·8%, 4·5-5·0), Campylobacter spp (3·5%, 0·4-6·3), astrovirus (2·7%, 2·2-3·1), and Cryptosporidium spp (2·0%, 1·3-2·6) exhibited the highest attributable burdens of diarrhoea in the first year of life. The major pathogens associated with diarrhoea in the second year of life were Campylobacter spp (7·9%, 3·1-12·1), norovirus GII (5·4%, 2·1-7·8), rotavirus (4·9%, 4·4-5·2), astrovirus (4·2%, 3·5-4·7), and Shigella spp (4·0%, 3·6-4·3). Rotavirus had the highest AF for sites without rotavirus vaccination and the fifth highest AF for sites with the vaccination. There was substantial variation in pathogens according to geography, diarrhoea severity, and season. Bloody diarrhoea was primarily associated with Campylobacter spp and Shigella spp, fever and vomiting with rotavirus, and vomiting with norovirus GII.Interpretation: There was substantial heterogeneity in pathogen-specific burdens of diarrhoea, with important determinants including age, geography, season, rotavirus vaccine usage, and symptoms. These findings suggest that although single-pathogen strategies have an important role in the reduction of the burden of severe diarrhoeal disease, the effect of such interventions on total diarrhoeal incidence at the community level might be limited

Impact of 10-valent pneumococcal conjugate vaccine (PCV10) on nasopharyngeal carriage in children 2 years of age: Data from a four-year time series cross-sectional study from Pakistan

The dataset described in this paper was collected for a time-series cross-sectional study exploring the impact of 10-valent Pneumococcal Conjugate Vaccine (PCV10) on nasopharyngeal (NP) carriage in children under 2 years of age from a rural population in Sindh, Pakistan. The study was carried out in two union councils of Matiari - Khyber and Shah Alam Shah Jee Wasi (Latitude 25.680298 / Longitude 68.502711). Data was collected on socio-demographics, clinical characteristics and vaccination status using android phone-based application. NP samples were collected using standard World Health Organisation (WHO) techniques, culture and serotyping was done using sequential Multiplex PCR described by Centre for Disease Control, USA. We looked at the carriage rate of vaccine type (VT) and non-vaccine type (NVT) serotypes over time in vaccinated and unvaccinated children. We additionally looked at the predictors for pneumococcal carriage. The uploaded dataset, available on Mendeley data repository (Nisar, Muhammad Imran (2021), Impact of PCV10 on nasopharyngeal carriage in children in Pakistan , Mendeley Data, V1, doi:10.17632/t79h6g97gr.1), has 3140 observations in CSV format. Additional files uploaded include a data dictionary and the set of questionnaires. The dataset and accompanying files can be used by other interested researchers to replicate our analysis, carry similar analysis under varying set of assumptions or perform additional exploratory or metanalysis

Direct and indirect effect of 10 valent pneumococcal vaccine on nasopharyngeal carriage in children under 2 years of age in Matiari, Pakistan

Background: Pakistan introduced Ten-valent pneumococcal-conjugate-vaccine PCV10 in 2012 as a 3 + 0 schedule without catch-up.Methods: Children \u3c2 years old in Matiari, Sindh provided nasopharyngeal swabs between 2014 and 2018, which were cultured for pneumococcus and serotyped through multiplex PCR at the Aga Khan University Hospital. Carriage rates over time for Vaccine-Type (VT) and Non-VT (NVT) serotypes were used to estimate direct, indirect, total and overall effects of vaccination. Regression analysis was used to determine factors associated with VT carriage.Results: Pneumococcus was detected in 2370/3140 (75%). VT carriage decreased overall, 16.1-9.6% (p-trend \u3c0.001); vaccinated (all 3 doses of PCV10 received) 11.3-8.1% (p-trend 0.031) and unvaccinated (no PCV10 dose received) 17.4-10.3% (p-trend 0.003) with a decline in serotypes 6B, 9V/9A and 19F. Immunization increased from 41.0% to 68.4% (p-trend 0.001). Direct effect of vaccine was 32.8% (95% CI 14.7-47.0%) and indirect effect 44.6%(95% CI 40.6-48.6%). Factors associated with decreased VT colonization were education 1-5 years (aOR 0.7, 95%CI 0.6-1.0), history of difficulty breathing (aOR 0.7, 95%CI 0.5-1.0), exposure to smoke (aOR 0.8, 95% CI 0.6-1.0), child fully immunized (aOR 0.7, 95%CI 0.5-1.0) and enrolled in 3rd (aOR 0.6, 95%CI 0.4-0.8) and 4th (aOR 0.6, 95%CI 0.5-0.9) year of the study whereas history of runny nose (aOR 1.5, 95% CI 1.2-1.9) was positively associated.Conclusions: Decrease in VT pneumococcal carriage in vaccinated and unvaccinated children indicates herd immunity. Sustained increase in vaccine coverage and close long-term surveillance is warranted