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Background: Healthcare-associated infections (HAIs) are a major global threat to patient safety. Systematic surveillance is crucial for understanding HAI rates and antimicrobial resistance trends and to guide infection prevention and control (IPC) activities based on local epidemiology. In India, no standardized national HAI surveillance system was in place before 2017. Methods: Public and private hospitals from across 21 states in India were recruited to participate in an HAI surveillance network. Baseline assessments followed by trainings ensured that basic microbiology and IPC implementation capacity existed at all sites. Standardized surveillance protocols for central-line–associated bloodstream infections (CLABSIs) and catheter-associated urinary tract infections (CAUTIs) were modified from the NHSN for the Indian context. IPC nurses were trained to implement surveillance protocols. Data were reported through a locally developed web portal. Standardized external data quality checks were performed to assure data quality. Results: Between May 2017 and April 2019, 109 ICUs from 37 hospitals (29 public and 8 private) enrolled in the network, of which 33 were teaching hospitals with >500 beds. The network recorded 679,109 patient days, 212,081 central-line days, and 387,092 urinary catheter days. Overall, 4,301 bloodstream infection (BSI) events and 1,402 urinary tract infection (UTI) events were reported. The network CLABSI rate was 9.4 per 1,000 central-line days and the CAUTI rate was 3.4 per 1,000 catheter days. The central-line utilization ratio was 0.31 and the urinary catheter utilization ratio was 0.57. Moreover, 3,542 (73%) of 4,742 pathogens reported from BSIs and 868 (53%) of 1,644 pathogens reported from UTIs were gram negative. Also, 1,680 (26.3%) of all 6,386 pathogens reported were Enterobacteriaceae. Of 1,486 Enterobacteriaceae with complete antibiotic susceptibility testing data reported, 832 (57%) were carbapenem resistant. Of 951 Enterobacteriaceae subjected to colistin broth microdilution testing, 62 (7%) were colistin resistant. The surveillance platform identified 2 separate hospital-level HAI outbreaks; one caused by colistin-resistant K. pneumoniae and another due to Burkholderia cepacia. Phased expansion of surveillance to additional hospitals continues. Conclusions: HAI surveillance was successfully implemented across a national network of diverse hospitals using modified NHSN protocols. Surveillance data are being used to understand HAI burden and trends at the facility and national levels, to inform public policy, and to direct efforts to implement effective hospital IPC activities. This network approach to HAI surveillance may provide lessons to other countries or contexts with limited surveillance capacity.
Periodic mesoporous materials possess high surface to volume ratio and nano-scale sized pores, making them potential candidates for heterogeneous catalysis, ion exchange, gas sensing and other applications. In this study, we use in situ small angle x-ray scattering (SAXS) and molecular dynamics (MD) simulations to investigate the mechanical and hydrothermal stability properties of periodic mesoporous SBA-15 silica and SBA-15 type aluminosilica (Al-SBA-15) to extreme conditions. The mesoporous SBA-15 silica and Al-SBA-15 aluminosilica possess amorphous frameworks and have similar pore size distribution (pore size ∼9-10 nm). The in situ SAXS measurements were made at the B1 beamline, at the Cornell High Energy Synchrotron Source (CHESS). The mesoporous SBA-15 silica and Al-SBA-15 aluminosilica specimens were loaded in a diamond anvil cell (DAC) for pressure measurements, and, separately, with water in the DAC for hydrothermal measurements to high P-T conditions (to 255 °C and ∼ 114 MPa). Analyses of the pressure-dependent SAXS data show that the mesoporous Al-SBA-15 aluminosilica is substantially more mechanically stable than the SBA-15 silica. Hydrothermal measurements show a small net swelling of the framework at elevated P-T conditions, due to dissolution of water into the pore walls. Under elevated P-T conditions, the Al-SBA-15 aluminosilica shows significantly greater hydrothermal stability than the SBA-15 silica. Our MD simulations show that the bulk modulus value of periodic mesoporous SBA-15 silica varies exponentially with percentage porosity. Molecular dynamics simulations are being made in order to better understand how the pore architecture and the chemical composition of the host structure govern the stability properties of the mesoporous materials.
For exploring the prospect of higher-k dielectric phase engineering on a high
mobility substrate, films of Hf1-xZrxO2 with
varying x-values (0 ≤ x ≤ 1) were deposited on
Al2O3 passivated Ge substrates using atomic layer
deposition (ALD) with a cyclic deposit-anneal-deposit-anneal (DADA) scheme. The
evolution of monoclinic to higher-k tetragonal structure with increasing
ZrO2 concentration was probed by grazing incident x-ray
diffraction and partial reciprocal space maps using the highly brilliant
synchrotron x-ray source at the Cornell High Energy Synchrotron Source (CHESS).
A primarily amorphous/nano-crystalline matrix of the asdeposited films changed
to randomly aligned grains of nanocrystalline MO2 (M=Hf, Zr)
after post deposition annealing at 800 °C for 200 seconds. In contrast,
the DADA films annealed for same thermal budget showed high degree of preferred
orientation along certain crystallographic directions. With increasing
ZrO2 content, the structure of the films changed from a monoclinic to
a tetragonal phase. A lower amount of ZrO2 (x = 0.33) was
required for stabilizing the tetragonal phase in films grown on
Al2O3 passivated Ge substrate as compared to similar
films grown on a Si substrate via the same DADA process (x ≥
Nanostructured anatase TiO2 is a promising material for gas sensing and photocatalysis. In order to modify its catalytic properties, the lanthanide (Ln) ions Eu3+, Gd3+, Nd3+ and Yb3+ were precipitated on the surface of TiO2 nanoparticles (NPs) by hydrothermal treatment. Results from Raman spectroscopy and X-ray diffraction (XRD) measurements show that the anatase structure of the TiO2 nanoparticles was preserved after hydrothermal treatment. SEM and TEM show a heterogeneous distribution in size and a nanocrystallite morphology of the TiO2 NPs (∼ 14 nm in size) and EDX confirmed the presence of the Ln-ion surface doping after hydrothermal treatment. An increase in photoluminescence (PL) was observed for the Ln-surface-doped TiO2 NPs when measurements were made in forming gas (5% H2 + 95% Ar) at 520 °C. In contrast, the PL measurements made at room temperature did not show any noticeable difference in forming gas or in ambient air. Our temperature-dependent PL results obtained in different gas environments are consistent with modification of oxygen-vacancies and hole-defects due to a combination of hydrothermal treatment and surface Ln-doping.
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