Molybdenum disulfide (MoS2) is being studied for a wide range of applications including lithium-ion batteries and hydrogen evolution reaction catalysts. In this paper, we present a single-step ...nonthermal plasma-enhanced chemical vapor deposition (PECVD) process for the production of two-dimensional MoS2. This method provides an alternative route to established CVD and plasma synthesis routes. The approach presented here synthesizes films in only a few minutes using elemental sulfur (S8) and molybdenum pentachloride (MoCl5) as precursors. Deposition utilizes a nonthermal inductively coupled plasma reactor and temperatures around 500 °C. Film growth characteristics and nucleation are studied as a function of precursor concentrations, argon flow rate, plasma power, and deposition time. Few-layer two-dimensional (MoS2) films were formed at low precursor concentrations. Films with nanoparticle-like features were formed when the precursor concentration was high. Noncontinuous nonstoichiometric films were found at low plasma power, while high plasma power led to continuous films with good stoichiometry. The vacancies and defects in these films may provide active sites for hydrogen evolution.
Gamma alumina (γ-Al2O3) is widely used as a catalyst and catalytic support due to its high specific surface area and porosity. However, synthesis of γ-Al2O3 nanocrystals is often a complicated ...process requiring high temperatures or additional post-synthetic steps. Here, we report a single-step synthesis of size-controlled and monodisperse, facetted γ-Al2O3 nanocrystals in an inductively coupled nonthermal plasma reactor using trimethylaluminum and oxygen as precursors. Under optimized conditions, we observed phase-pure, cuboctahedral γ-Al2O3 nanocrystals with defined surface facets. Nuclear magnetic resonance studies revealed that nanocrystal surfaces are populated with AlO6, AlO5 and AlO4 units with clusters of hydroxyl groups. Nanocrystal size tuning was achieved by varying the total reactor pressure yielding particles as small as 3.5 nm, below the predicted thermodynamic stability limit for γ-Al2O3.
Background:
Lipocalin 2 (LCN2) may be involved in the immunopathogenesis of multiple sclerosis (MS) and might further impact on iron homoeostasis. Brain iron accumulates in MS; however, the ...association to iron-related proteins is still unsolved.
Objective:
To investigate cerebrospinal fluid (CSF) and serum LCN2, transferrin (Trf) and ferritin in early MS in relation to disease evolution and longitudinal brain iron accumulation.
Methods:
We analysed CSF and serum LCN2 by enzyme-linked immunosorbent assay (ELISA) and Trf and ferritin by nephelometry in 55 patients (45 clinically isolated syndrome (CIS), 10 MS, median clinical follow-up 4.8 years) and 63 controls. In patients, we assessed sub-cortical grey matter iron by 3T magnetic resonance imaging (MRI) R2* relaxometry (median imaging follow-up 2.2 years).
Results:
Compared to controls serum (p < 0.01), CSF (p < 0.001) LCN2 and CSF Trf (p < 0.001) levels were reduced in the patients. CSF LCN2 correlated with CSF Trf (r = 0.5, p < 0.001). In clinically stable patients, CSF LCN2 levels correlated with basal ganglia iron accumulation (r = 0.5, p < 0.05). In CIS, higher CSF LCN2 levels were associated with conversion to clinically definite MS (p < 0.05).
Conclusion:
We demonstrate altered LCN2 regulation in early MS and provide first evidence for this to be possibly linked to both clinical MS activity and iron accumulation in the basal ganglia.
The Infectious Diseases Working Party of the European Blood and Marrow Transplant Group conducted a survey to obtain information about the frequency, presentation, and treatment of mycobacterial ...infection (MBI) in stem cell transplant (SCT) recipients. Among 29 centers, MBI was diagnosed in 0.79% of 1513 allogeneic and 0.23% of 3012 autologous SCT recipients during 1994-1998 a median of 160 days after transplantation. The mean interval between first symptoms and diagnosis was 29 days and was still longer for patients with atypical MBI or recipients of corticosteroid therapy. The prevalence of MBI was highest among those who received matched unrelated or mismatched STCs from related donors. Of 31 patients, 20 had tuberculosis, 8 had atypical MBI, and 3 had diagnoses based on histological findings only. Five patients (16%) died, all of whom had received an allogeneic SCT. Because of the increased numbers of unmatched donors and transplantation programs in countries with a high prevalence of tuberculosis, constant vigilance is required to early detect MBI in SCT recipients.
Perceiving three-dimensional video imagery appropriately in a display requires matching parameters throughout the imaging pathway, such as inter-aperture distance at the stereoscopic camera side with ...parallax shifting at the display side. In addition, many tradeoffs and compromises are often made at different points in the imaging pathway, leading to common perceptual distortions. Some of these may be simple two-dimensional image distortions such as display surface noise, while others are three-dimensional distortions, such as global geometric scene distortions and localized depth errors around edges. There is an increasing use of various forms of signal processing to modify the images, either for compensation of distortions due to system limitations, display constraints, formatting and compression for efficient transmission, or making depth range adjustments dependent on the display viewing conditions. Perceptual issues are critical to the design of the entire imaging pathway and this paper will highlight some of those due to stereoscopic signal processing.
Summary
Objective
The goal of this study was to examine if breastfeeding duration by gestational diabetes mellitus status impacted the prevalence of obesity in offspring.
Methods
Data were obtained ...from a 2011 phone survey with caregivers of low‐income children (2–4 years) participating in the Women, Infants and Children programme in Los Angeles County. The final sample included 2295 children, 84% Hispanic and 48% female. Chi‐square and binary logistic regression were used to assess gestational diabetes status and breastfeeding duration on the prevalence of obesity, with the following a priori covariates: child's ethnicity, birth weight, age in months and sex.
Results
Breastfeeding and gestational diabetes were significantly associated with obesity prevalence (P < 0.01). Using gestational diabetes mellitus and no breastfeeding as the referent category, gestational diabetes mellitus offspring who were breastfed ≥12 months had a 72% decrease in obesity prevalence (adjusted odds ratio = 0.28, confidence interval 0.89–0.03, P = 0.05).
Conclusions
These findings suggest that > 12 months of breastfeeding duration in the gestational diabetes mellitus group and any duration of breastfeeding in the non‐gestational diabetes mellitus mothers is needed to reduce obesity levels in a primarily Hispanic population.
Summary
Background
Bronchial asthma is characterized by chronic airway inflammation and airway remodelling which occurs in both proximal and distal airways. These changes are associated with ...development of airway hyper‐responsiveness and airflow limitation.
Objective
This study was aimed to analyse whether chronic inhalative allergen challenges in mice lead to morphological and physiological changes comparable with this phenotype.
Methods
For this purpose, BALB/c mice were systemically sensitized to ovalbumin (OVA) followed by aerosol allergen challenges on 2 consecutive days per week for 12 weeks.
Results
In chronically challenged mice, tissue inflammation in proximal as well as distal airways was observed with a predominance of lymphocytes within the cellular infiltrate. In contrast, inflammation in the airway lumen decreased over time. These changes were associated by a shift in bronchoalveolar lavage–cytokine levels from IL‐4, IL‐5 and TNF‐α production (during the acute phase) towards markedly increased levels of TGF‐β during the chronic phase. Goblet cell hyperplasia and subepithelial fibrosis occurred throughout the airway tree. In terms of lung function, chronically challenged mice developed persistent bronchial hyper‐responsiveness and progressive airflow limitation. Six weeks after OVA aerosol discontinuation, airway inflammation still persisted although lung function was normalized.
Conclusion
These data indicate that our model of chronic aerosol allergen challenges leads to a phenotype of experimental asthma with participation of distal airways and persistence of inflammation thereby resembling many morphological and physiological aspects of human bronchial asthma.
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•O2 treatment of Mo2C catalysts suppresses metallic/alkaline catalytic activity.•O2 co-feed reversibly alters Brønsted acid site density on Mo2C by a factor of ∼30.•O∗–Mo2C Brønsted ...acid sites dehydrate IPA with a rate-determining step of β-hydrogen scission.•Bulk 2–5nm orthorhombic β-Mo2C crystallites were not affected by O2 exposure.
Acid site densities could be reversibly tuned by a factor of ∼30 using an O2 co-feed, which reversibly creates Brønsted acid sites on the carbide surface without altering the bulk crystal structure of 2–5nm Mo2C crystallites. Unimolecular isopropanol (IPA) dehydration at 415K, a probe reaction, occurred on Brønsted acid sites of these oxygen-modified carbides with an intrinsic activation energy of 93±1.3kJmole−1 via an E2 elimination mechanism with a kinetically-relevant step of β-hydrogen scission. Site densities were estimated via in situ 2,6-di-tert-butylpyridine (DTBP) titration and used to calculate a turnover frequency (TOF) of 0.1s−1, which was independent of site density. Oxygen co-processing allows for facile in situ tunability of acidic and metallic sites on highly oxophilic metal carbides.
Forty-one cases of toxoplasmosis were diagnosed in 15 European transplantation centers in patients who had undergone allogeneic hematopoietic stem cell transplantation (HSCT) from 1994 through 1998. ...Most patients (39 94%) were seropositive for Toxoplasma gondii before they underwent transplantation, and 30 (73%) had developed moderate to severe acute graft-versus-host disease before they developed toxoplasmosis. Thirty-five (85%) patients had Toxoplasma disease with evidence of organ involvement, whereas 6 (15%) patients had Toxoplasma infection, as defined by fever and a positive polymerase chain reaction (PCR) finding for T. gondii in blood. Nine patients were diagnosed at autopsy. Thirty patients (73%) had not received antimicrobial prophylaxis with anti-Toxoplasma activity after undergoing transplantation. The median day of onset of disease after HSCT was 64. Twenty-two (63%) patients died from toxoplasmosis, and 23 (66%) received adequate anti-Toxoplasma therapy for ⩾3 days. Among these 23 patients, 11 (48%) showed a complete response and 3 (13%) showed improvement. In univariate and multivariate analyses, having received adequate therapy and experiencing late infection (>63 days after HSCT) were associated with a lower risk of dying from toxoplasmosis. Toxoplasmosis after HSCT is a severe infection with a high mortality rate even when diagnosed soon after HSCT, and PCR may help establish the diagnosis earlier.
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