Impact of Pregrown SiOx on the Carrier Selectivity and Thermal Stability of Molybdenum-Oxide-Passivated Contact for Si Solar Cells.

Thin SiOx interlayers are often formed naturally during the deposition of transition metal oxides on silicon surfaces due to interfacial reaction. The SiOx layer, often only several atomic layers thick, becomes the interface between the Si and deposited metal oxide and can therefore influence the electrical properties and thermal stability of the deposited stack. This work explores the potential benefits of controlling the properties of the SiOx interlayer by the introduction of pregrown high-quality SiOx which also inhibits the formation of low-quality SiOx from the metal-oxide deposition process. This work demonstrates that a high-quality pregrown SiOx can reduce the interfacial reaction and results in a more stoichiometric MoOx with improved surface passivation and thermal stability linked to its lower Dit. Detailed experimental data on carrier selectivity, carrier transport efficiency, annealing stability up to 250 °C, and in-depth material analysis are presented.

Stroke Mortality Outcomes in Uganda.

BACKGROUND AND PURPOSE: Stroke outcome data in Uganda is lacking. The objective of this study was to capture 30-day mortality outcomes in patients presenting with acute and subacute stroke to Mbarara Regional Referral Hospital (MRRH) in Uganda. METHODS: A prospective study enrolling consecutive adults presenting to MRRH with abrupt onset of focal neurologic deficits suspicious for stroke, from August 2014 to March 2015. All patients had head computed tomography (CT) confirmation of ischemic or hemorrhagic stroke. Data was collected on mortality, morbidity, risk factors, and imaging characteristics. RESULTS: Investigators screened 134 potential subjects and enrolled 108 patients. Sixty-two percent had ischemic and 38% hemorrhagic stroke. The mean age of all patients was 62.5 (SD 17.4), and 52% were female. More patients had hypertension in the hemorrhagic stroke group than in the ischemic stroke group (53% vs. 32%, p = 0.0376). Thirty-day mortality was 38.1% (p = 0.0472), and significant risk factors were National Institutes of Health Stroke Scale (NIHSS) score, female sex, anemia, and HIV infection. A one unit increase of the NIHSS on admission increased the risk of death at 30 days by 6%. Patients with hemorrhagic stroke had statistically higher NIHSS scores (p = 0.0408) on admission compared to patients with ischemic stroke, and also had statistically higher Modified Rankin Scale (mRS) scores at discharge (p = 0.0063), and mRS score change from baseline (p = 0.04). CONCLUSIONS: Our study highlights an overall 30-day stroke mortality of 38.1% in southwestern Uganda, and identifies NIHSS at admission, female sex, anemia, and HIV infection as predictors of mortality.

Acute Ischemic Stroke as a Result of Paradoxical Embolus in a Patient with Renal Cell Carcinoma, Intravenous Tumor Thrombus Extension, and Patent Foramen Ovale.

INTRODUCTION: Patent foramen ovale is a common congenital cardiac abnormality. An association with acute ischemic stroke is well described. Extension of renal cell carcinoma (RCC) into the adjacent veins is common. Surgical resection is felt to be an effective approach to treatment, even in the setting of extensive venous involvement. CASE REPORT: A 55-year-old woman with recently diagnosed right renal mass and cavoatrial tumor thrombus was transferred to our facility for surgical resection. She subsequently underwent open radical right nephrectomy, regional lymph node dissection, inferior vena cava and right atrial tumor thrombectomy, and resection of the infrahepatic vena cava. An intraoperative transesophageal echocardiogram confirmed the absence of tumor thrombus from the inferior vena cava and right atrium and also identified a patent foramen ovale (PFO). Upon weaning sedation, she was noted to be agitated and have left hemiplegia. Her National Institutes of Health Stroke Scale (NIHSS) was 30 and Glasgow Coma Scale (GCS) 6. The computerized tomography scan of head revealed extensive hypoattenuation right in the middle and left posterior cerebral artery territories. There was associated cerebral edema and 5-mm midline shift. In the setting of devastating neurological injury, her family elected to transition to comfort care and the patient died on the postoperative day 7. CONCLUSIONS: This is the first reported case of intraoperative paradoxical embolism in the setting of RCC with cavoatrial extension and PFO. The presence of PFO may be a risk factor for severe cerebrovascular complications in the surgical management of RCC with venous involvement.

A comparison of the Full Outline of Unresponsiveness (FOUR) and Glasgow Coma Scale (GCS) Scores in Predicting Mortality Among Patients with Reduced Level of Consciousness in Uganda.

BACKGROUND: Reduced level of consciousness (LOC) is a common cause of presentation among acutely ill adults in sub-Saharan Africa and is associated with high rates of mortality. Although the Full Outline of Unresponsiveness (FOUR) score is often used in clinical practice, its utility in predicting mortality has not been assessed in the region. METHODS: We prospectively enrolled adults presenting with reduced LOC to Mbarara Regional Referral Hospital in Uganda. We recorded clinical and laboratory data and performed the FOUR and Glasgow Coma Scale (GCS) scores at admission. We used survival analysis, fit Cox proportional hazards regression models to assess the predictive properties of the two scores, and compared their performance using area under the receiver operating characteristic curve (AUROC). RESULTS: We enrolled 359 patients, mean (SD) age was 51 (22.2) years, and 58% (210/359) were male. The median (interquartile range) admission FOUR and GCS scores were 13.0 (3.0-16.0) and 10.0 (3.0-14.0), respectively. Subjects with the FOUR score of 0-11 had a 2.6-fold higher hazard of 30-day mortality (HR 2.6, 95% CI 1.9-3.6, p < 0.001) compared to those with the score of 12-16. Those with the GCS score of 3-8 had a 2.7-fold higher hazard of 30-day mortality (HR 2.7, 95% CI 2.0-3.8, p < 0.001) compared to those with the score of 9-15. The AUROC (95% CI) for the FOUR score and GCS score was 0.68 (0.62-0.73) and 0.67 (0.62-0.73), respectively (p = 0.825). CONCLUSIONS: The FOUR score is comparable to the GCS score in predicting mortality in Uganda. Our findings support the introduction of the FOUR score in guiding the management of patients with reduced LOC in sub-Saharan Africa.

Effect of Empiric Anti-Mycobacterium tuberculosis Therapy on Survival Among Human Immunodeficiency Virus-Infected Adults Admitted With Sepsis to a Regional Referral Hospital in Uganda.

BACKGROUND: Mycobacterium tuberculosis is the leading cause of bloodstream infection among human immunodeficiency virus (HIV)-infected patients with sepsis in sub-Saharan Africa and is associated with high mortality rates. METHODS: We conducted a retrospective study of HIV-infected adults with sepsis at the Mbarara Regional Referral Hospital in Uganda to measure the proportion who received antituberculosis therapy and to determine the relationship between antituberculosis therapy and 28-day survival. RESULTS: Of the 149 patients evaluated, 74 (50%) had severe sepsis and 48 (32%) died. Of the 55 patients (37%) who received antituberculosis therapy, 19 (35%) died, compared with 29 of 94 (31%) who did not receive such therapy (odds ratio, 1.34; 95% confidence interval [CI], .56-3.18; P = .64). The 28-day survival rates did not differ significantly between these 2 groups (log-rank test, P = .21). Among the 74 patients with severe sepsis, 9 of 26 (35%) who received antituberculosis therapy died, versus 23 of 48 (48%) who did not receive such therapy (odds ratio, 0.58; 95% CI, .21-1.52; P = .27). In patients with severe sepsis, antituberculosis therapy was associated with an improved 28-day survival rate (log-rank test P = .01), and with a reduced mortality rate in a Cox proportional hazards model (hazard ratio, 0.32; 95% CI, .13-.80; P = .03). CONCLUSIONS: Empiric antituberculosis therapy was associated with improved survival rates among patients with severe sepsis, but not among all patients with sepsis.

Validation of the Intracerebral Hemorrhage Score in Uganda.

Background and Purpose- Rates of intracerebral hemorrhage (ICH) are estimated to be highest globally in sub-Saharan Africa. However, outcomes of ICH are poorly described and standard prognostic markers for ICH have not been validated in the region. Methods- We enrolled consecutive patients with computed tomography-confirmed ICH at a referral hospital in southwestern Uganda. We recorded demographic, clinical, and radiographic features of ICH, and calculated ICH scores. We fit Poisson regression models with robust variance estimation to determine predictors of case fatality at 30 days. Results- We enrolled 73 individuals presenting with computed tomography-confirmed ICH (mean age 60 years, 45% [33/73] female, and 14% [10/73] HIV-positive). The median ICH score was 2 (interquartile range, 1-3; range, 0-5). Case fatality at 30 days was 44% (32/73; 95% CI, 33%-57%). The 30-day case fatality increased with increasing ICH score of 0, 1, and 5 from 17%, 23%, to 100%, respectively. In multivariable-adjusted models, ICH score was associated with case fatality (adjusted relative risk, 1.48; 95% CI, 1.23-1.78), as were HIV infection (adjusted relative risk, 1.92; 95% CI, 1.07-3.43) and female sex (adjusted relative risk, 2.17; 95% CI, 1.32-3.59). The ICH score moderately improved with the addition of a point each for female sex and HIV serostatus (0.81 versus 0.73). Conclusions- ICH score at admission is a strong prognostic indicator of 30-day case fatality in Uganda. Our results support its role in guiding the care of patients presenting with ICH in the region.

Stroke in Human Immunodeficiency Virus-infected Individuals in Sub-Saharan Africa (SSA): A Systematic Review.

BACKGROUND: Human immunodeficiency virus (HIV) infection is associated with worse outcomes after stroke, but this association is less well-described in sub-Saharan Africa (SSA). We reviewed literature on stroke among people living with HIV (PLWH) in SSA. METHODS: We systematically reviewed published literature for original clinical stroke studies conducted in SSA that included PLWH. We included studies that reported data on presenting characteristics, risk factors, and/or outcomes after stroke. RESULTS: Seventeen studies (N = 478) met inclusion criteria. At the time of stroke presentation, PLWH had a median age ranging from 32 to 43 years. Subjects had low CD4 counts (median CD4, 108-225 cells/µl), and most were antiretroviral therapy-naïve. Fever, seizures, and concurrent opportunistic infections were common at presentation. Ischemic stroke accounted for up to 96% of strokes, which were mostly located in the anterior circulation territory. In studies comparing PLWH with HIV-uninfected individuals, PLWH had more frequent coagulopathy, greater stroke severity, (72% versus 36% National Institutes of Health Stroke Scale >13, P = .02), longer hospital length of stay (30.5 versus <10 days), and a higher 30-day mortality rate (23% versus 10.5%, P = .007). CONCLUSION: Stroke in PLWH in SSA occurs at a young age, in those with advanced disease, and is associated with worse outcomes than in HIV-uninfected comparators. Stroke in young individuals in the region should prompt HIV testing, and ongoing efforts to promote early antiretroviral therapy initiation might also help decrease stroke incidence, morbidity, and mortality in the region.

Vitamin D Receptor ApaI (rs7975232) Polymorphism Confers Decreased Risk of Pulmonary Tuberculosis in Overall and African Population, but not in Asians: Evidence from a Meta-analysis.

GOALS: The involvement of the VDR ApaI gene polymorphism in the development of pulmonary tuberculosis (PTB) has been reported by numerous published studies and yielded inconsistent results. The present meta-analysis evaluated the association of VDR ApaI polymorphism and risk of PTB occurrence. PROCEDURES: PubMed (Medline), EMBASE and Google Scholar web-databases were searched and a meta-analysis was performed by calculating the pooled odds ratios (ORs) and 95% confidence intervals (95% CIs). RESULTS: This meta-analysis included a total of 14 eligible studies comprising of 1958 confirmed PTB cases and 2938 controls. We observed decreased risk of PTB in allelic (a vs. A: p=0.003; OR=0.873, 95% CI=0.798 to 0.955), homozygous (aa vs. AA: p=0.006; OR=0.761, 95% CI=0.626 to 0.924), dominant (aa+Aa vs. AA: p=0.039; OR=0.874, 95% CI=0.769 to 0.993) and recessive (aa vs. AA+Aa: p=0.025; OR=0.819, 95% CI=0.688 to 0.975) genetic models. During subgroup analysis, allele (a vs. A: p=0.005; OR=0.846, 95% CI=0.753 to 0.951), homozygous (aa vs. AA: p=0.002; OR=0.662, 95% CI=0.513 to 0.854) and recessive genetic models (aa vs. AA+Aa: p=0.003; OR=0.709, 95% CI=0.566 to 0.889) demonstrated decreased PTB risk in African population. However, no significant association was observed in Asian population. CONCLUSION: In conclusion, VDR ApaI polymorphism is significantly associated with decreased risk of PTB for in overall and African population, but not in Asians.

Improved Self-cleaning Properties of an Efficient and Easy to Scale up TiO2 Thin Films Prepared by Adsorptive Self-Assembly.

Transparent titania coatings have self-cleaning and anti-reflection properties (AR) that are of great importance to minimize soiling effect on photovoltaic modules. In this work, TiO2 nanocolloids prepared by polyol reduction method were successfully used as coating thin films onto borosilicate glass substrates via adsorptive self-assembly process. The nanocolloids were characterized by transmission electron microscopy and x-ray diffraction. The average particle size was around 2.6 nm. The films which have an average thickness of 76.2 nm and refractive index of 1.51 showed distinctive anti soiling properties under desert environment. The film surface topography, uniformity, wettability, thickness and refractive index were characterized using x-ray diffraction, atomic force microscopy, scanning electron microscopy, water contact angle measurements and ellipsometry. The self-cleaning properties were investigated by optical microscopy and UV-Vis spectroscopy. The optical images show 56% reduction of dust deposition rate over the coated surfaces compared with bare glass substrates after 7 days of soiling. The transmission optical spectra of these films collected at normal incidence angle show high anti-reflection properties with the coated substrates having transmission loss of less than 6% compared to bare clean glass.

Structural and physical properties of the dust particles in Qatar and their influence on the PV panel performance.

Recently, extensive R&D has been conducted, both by industry and academia, to significantly raise the conversion efficiency of commercial photovoltaic (PV) modules. The installation of PV systems aimed at optimizing solar energy yield is primarily dictated by its geographic location and installation design to maximize solar exposure. However, even when these characteristics have been addressed appropriately, there are other factors that adversely affect the performance of PV systems, namely the temperature-induced voltage decrease leading to a PV power loss, and the dust accumulation (soiling). The latter is the lesser acknowledged factor that significantly influences the performance of PV installations especially in the Middle East region. In this paper we report on the investigation of the structural and physical properties of the desert-dust particles in the State of Qatar. The dust particles were collected directly from the PV panels installed in desert environment and characterized by different techniques, including scanning electron, optical and atomic force microscopies, X-ray diffraction, energy-dispersive, UV-Vis, micro-Raman and Fourier transform infrared spectroscopy. The vibrating sample magnetometry analyses were also conducted to study the magnetic properties of the dust particles. The influence of the dust accumulation on the PV panel performance was also presented and discussed.

A simple prognostic index based on admission vital signs data among patients with sepsis in a resource-limited setting.

INTRODUCTION: In sub-Saharan Africa, vital signs are a feasible option for monitoring critically ill patients. We assessed how admission vital signs data predict in-hospital mortality among patients with sepsis. In particular, we assessed whether vital signs data can be incorporated into a prognostic index with reduced segmentation in the values of included variables. METHODS: Subjects were patients with sepsis hospitalized in Uganda, who participated in two cohort studies. Using restricted cubic splines of admission vital signs data, we predicted probability of in-hospital death in the development cohort and used this information to construct a simple prognostic index. We assessed the performance of the index in a validation cohort and compared its performance to that of the Modified Early Warning Score (MEWS). RESULTS: We included 317 patients (167 in the development cohort and 150 in the validation cohort). Based on how vital signs predicted mortality, we created a prognostic index giving a score of 1 for: respiratory rates ≥30 cycles/minute; pulse rates ≥100 beats/minute; mean arterial pressures ≥110/<70 mmHg; temperatures ≥38.6/<35.6°C; and presence of altered mental state defined as Glasgow coma score ≤14; 0 for all other values. The proposed index (maximum score = 5) predicted mortality comparably to MEWS. Patients scoring ≥3 on the index were 3.4-fold (95% confidence interval (CI) 1.6 to 7.3, P = 0.001) and 2.3-fold (95% CI 1.1 to 4.7, P = 0.031) as likely to die in hospital as those scoring 0 to 2 in the development and validation cohorts respectively; those scoring ≥5 on MEWS were 2.5-fold (95% CI 1.2 to 5.3, P = 0.017) and 1.8-fold (95% CI 0.74 to 4.2, P = 0.204) as likely to die as those scoring 0 to 4 in the development and validation cohorts respectively. CONCLUSION: Among patients with sepsis, a prognostic index incorporating admission vital signs data with reduced segmentation in the values of included variables adequately predicted mortality. Such an index may be more easily implemented when triaging acutely-ill patients. Future studies using a similar approach may develop indexes that can be used to monitor treatment among acutely-ill patients, especially in resource-limited settings.