Synergistic Approach toward Erbium-Passivated Triple-Anion Organic-Free Perovskite Solar Cells with Excellent Performance for Agrivoltaics Application.

All-inorganic perovskite solar cells (IPSCs) have gained massive attention due to their less instability against common degradation factors (light, heat, and moisture) than their organic-inorganic hybrid counterparts. Inorganic perovskites bear a general formula of CsPbX3 (X = Cl, I, Br). The mixed halide CsPbIBr2 perovskite possesses an intermediate band gap of 2.03 eV with enhanced stability, which is still available for photovoltaic applications and the research focus of this work. We present a synergistic approach of pre-heated solution dropping with inorganic additive inclusion to deposit the organic-free triple anion CsPbIBr2 PSC. Erbium (Er)-passivated triple-anion CsI(PbBr2)0.97(ErCl3)0.03 IPSCs with inorganic carrier selective layers (CTLs), that is, organic-free, are fabricated with enhanced carrier diffusion length and crystalline grain size while lessening the grain boundaries near perovskite active layer (PAL)-bulk/carrier selective interfaces. As a result, the trap-state densities within the perovskite bulk were suppressed with stabilized CTL/PAL interfaces for smooth and enhanced carrier transportation. Therefore, for the first time, we contradict the common belief of VOC loss due to halide segregation, as a nice VOC of about 1.34 V is achieved for an organic-free IPSC through enriching initial radiative efficiency, even when halide segregation is present. The optimized organic-free IPSC yielded a power conversion efficiency of 11.61% and a stabilized power output of 10.72%, which provides the potential opportunity to integrate into agrivoltaics (AgV) projects.

Surface Modification of Magnetic Iron Oxide Nanoparticles.

Functionalized iron oxide nanoparticles (IONPs) are of great interest due to wide range applications, especially in nanomedicine. However, they face challenges preventing their further applications such as rapid agglomeration, oxidation, etc. Appropriate surface modification of IONPs can conquer these barriers with improved physicochemical properties. This review summarizes recent advances in the surface modification of IONPs with small organic molecules, polymers and inorganic materials. The preparation methods, mechanisms and applications of surface-modified IONPs with different materials are discussed. Finally, the technical barriers of IONPs and their limitations in practical applications are pointed out, and the development trends and prospects are discussed.

The aggregation of Fe3+ and their d-d radiative transitions in ZnSe:Fe3+ nanobelts by CVD growth.

Transition metal (TM) doped II-VI semiconductors have attracted great attention due to their luminescence and diluted magnetism. In this study, the Fe3+-doped ZnSe nanobelts (NBs) were grown by a facile CVD method. The surface morphology observed via SEM is smooth and clean and the elemental composition measured via EDS confirms that the Fe3+ ions were incorporated into ZnSe NBs successfully. The micro-Raman scattering spectra demonstrate that the as-prepared NBs have the zinc blende structure. Furthermore, the Raman spectra of the Fe3+-doped NBs were compared with those of pure and Fe2+-doped reference samples. The former with a higher signal-to-noise ratio, an enhanced 2LO mode, a stronger LO mode redshift and a larger intensity ratio of LO/TO mode as well as the lower acoustic phonon modes confirms the better crystallization and the stronger electron-phonon coupling on Fe3+-incorporation. The emission of single Fe3+ ion, assigned to the 4T1 → 6A1 transition, was observed at about 570 nm. Moreover, increasing the doping concentration of Fe3+ ions caused the formation of different Fe-Fe coupled pairs in the lattice, which emitted light at about 530-555 nm for an antiferromagnetic-coupled pair, possibly due to the stacking faults and at about 620-670 nm for a ferromagnetic-coupled pair.

Mammographic breast density: Predictive value for pathological response to neoadjuvant chemotherapy in breast cancer patients.

BACKGROUND: This study aims to evaluate the relation between mammographic breast density (BD) and pathological response to neoadjuvant chemotherapy. METHODS: In this retrospective study, 241 breast cancer patients who received neoadjuvant chemotherapy were included. BD was assessed in mammograms already performed at diagnosis. Pathological complete response (pCR) and pathological stage were correlated with BD, tumour phenotype and other clinico-pathological factors. RESULTS: Patients with low BD had better pCR compared to those with high density (30.5% vs 19.5% respectively, OR = 1.8, 95% CI = 0.98-3.3, p = 0.056) which was more pronounced after adjustment with body mass index (BMI) (OR = 2.4, 95% CI = 1.2-4.8, p = 0.011). HER2-positive disease (32.5% vs. 18.4%, OR = 2.2, 95% = 1.2-4.0, p = 0.01), lower BMI (OR = 1.1, 95% CI = 1.03-1.15, p = 0.004) and lower clinical stage (p = 0.002) were significant predictors of pCR in univariate analysis. In multivariate analysis, low BD (OR = 2.7, 95% CI = 1.3-5.5, p = 0.006) and lower BMI (OR = 1.1, 95% CI = 1.03-1.17, p = 0.003) were independent predictors of better pCR, while early clinical stage (I, II) was of borderline significance (OR = 2.6, 95% CI = 0.99-6.7, p = 0.052). High BD (OR = 1.8, 95% CI = 1.1-3.2, p = 0.03), advanced clinical stage (III) (OR = 1.5, 95% CI = 1.03-2.1, p = 0.03) and higher BMI (OR = 1.06, 95% CI = 1.02-1.11, p = 0.006) were significant predictors of advanced pathological stage. CONCLUSION: Low mammographic BD, low BMI and early clinical stage were associated with improved pCR rate and lower pathological stage after neoadjuvant chemotherapy. BD had more pronounced association with response to chemotherapy after adjustment with BMI.

Efficacy of combined metformin-clomiphene citrate in comparison with clomiphene citrate alone in infertile women with polycystic ovarian syndrome (PCOS).

BACKGROUND: Polycystic ovary syndrome (PCOS) is the most common endocrinopathy in women and is associated with the reproductive and metabolic disorders. OBJECTIVES: To compare the ovulation and conception rates after the treatment with Clomiphene Citrate (CC) alone and in combination with metformin in infertile patients presented with polycystic ovarian syndrome (PCOS). MATERIAL & METHODS: This randomized controlled trial of independent cases and controls was conducted in the Department of Obstetrics and Gynecology, Hera General Hospital, Makkah, Saudi Arabia, during 2008. The 42 subjects diagnosed as PCOS were divided into group A and B (21 subjects in each) for the management with CC + metformin and CC alone, respectively. Group A received 500mg of metformin continuously, three times a day from the first cycle, for 6 months or until the pregnancy was confirmed. In both groups, CC was started with a dose of 50 mg from day-2 until day-6 of the menstrual cycle. The dose of CC was increased to 100 mg in the second and 150 mg in the third cycle, and then 150 mg remained for the rest of three cycles. With ovulation, the dose of CC was unaltered in both groups. Data were analyzed by using SPSS version 16. RESULTS: More than 50% of the females in both groups had a body mass index of >25. Group A achieved a higher rate of regular cycles, ovulation success, and conception than group B (71.4% vs. 38.1%; p=0.03), (76.2% vs. 38.1%; p=0.021) and (66.6% vs. 28.6%, p=0.01), respectively. CONCLUSION: Management with metformin + CC increased the ovulation and conception rates.

Physicians' Belief about Organ Donation.

BACKGROUND: Several studies have suggested that knowledge, attitudes and determinants concerning organ donation are influenced by many factors including gender, educational level, occupation, sociodemographic status, income level, culture and religion. OBJECTIVE: To highlight the awareness of cardiopulmonary and brain death (CD and BD) among the physicians and their belief about the organ donation. METHODS: In a cross-sectional study, 15% of 1700 physicians working under the auspices of Ministry of Health in Makkah region, were selected randomly from two hospitals of Makkah city, i.e., Alnoor Specialist Hospital and King Abdalaziz Hospital. A self-administered questionnaire with dichotomous answers was distributed to them. RESULTS: Out of 185 respondents, 174 (94.1%) identified the right definition of BD and CD and 155 (83.3%) agreed organ donation. The difference among physicians to differentiate CD from BD was not significant (p=0.2). CONCLUSION: Physicians had enough knowledge to differentiate CD from BD; most of them are highly positive regarding the concept of organ donation.

Prevalence of intestinal parasites and bacteria among food handlers in a tertiary care hospital.

OBJECTIVES: The aim of this work is to determine the prevalence of intestinal parasites and bacteria among the food handlers. MATERIALS AND METHODS: Two hundred food-handlers were subjected to a cross-sectional study working in the kitchen of a tertiary care hospital, i.e., Alnoor Specialist Hospital, Makkah, Saudi Arabia from February 2 to 27, 2009. The stool samples were examined for intestinal parasites following direct microscopic examination, formol ether concentration (Ritchie), and staining with modified acid fast staining techniques. For enteropathogenic bacteria samples were inoculated onto MacConkey's agar, deoxycholate citrate agar, xylose lysine deoxycholate agar as per the World Health Organization protocol. Fingernail materials were examined microscopically for enteropathogenic bacteria and parasites. RESULTS: The majority (80%) of the food-handlers were young adults aged from 22 to 42 years. No intestinal parasites were detected from fingernail contents. Forty six (23%) stool specimens were positive for intestinal para¬sites. Giardia lamblia 18 (9%) was most frequent among the 10 different types of detected intestinal parasites followed by Entamoeba histolytica 9 (4.5%). No pathogenic bacteria were detected in all stool samples, whereas finger nails showed isolation of microorganisms as coagulase-negative staphylococci 79 (39.5%), followed by Staphylococcus aureus 35 (17.5%). CONCLUSION: The findings emphasized the importance of food handlers as potential sources of infections and suggested health institutions for appropriate hygienic and sanitary control measures.

The epidemiology of stroke in Pakistan: past, present, and future.

Stroke is a major public health problem in developing countries of South Asia. In this paper, we review the epidemiology of stroke in Pakistan. Most of the available data are based on hospital-centred case series addressing established stroke risk factors, stroke-related mortality and disability, functional status, and case fatality rates. There are limited population-based data regarding the prevalence of established stroke risk factors in the general population, and no epidemiologic studies have been conducted to specifically identify potential stroke risk factors unique to the region. The limited data that are available from Pakistan indicate that stroke epidemiology differs between Pakistan and Western populations - in Pakistan first stroke occurs at a younger age, particularly among women, and there is a higher proportion of haemorrhagic strokes. Besides the established stroke risk factors (e.g. hypertension, smoking, and diabetes) some potentially unique stroke risk factors related to life style and dietary habits such as huqqa smoking, use of dalda and desi ghee, and orally consumed forms of tobacco, may exist in Pakistan, and warrant further investigation. The shortage of trained stroke epidemiologists is a major limiting factor to the conduct of epidemiological stroke studies in Pakistan. Epidemiologic data are essential to guide health policy development aimed at decreasing the mortality and morbidity from stroke in Pakistan. To facilitate this process, medical professionals in Pakistan could participate in the World Health Organization's STEPwise approach to stroke surveillance, which provides a framework for data collection and comparison between and within populations.

Using EBSD and TEM-Kikuchi patterns to study local crystallography at the domain boundaries of lead zirconate titanate.

Reliable EBSD mapping of 90 degree domains in a tetragonal ferroelectric perovskite has been achieved for the first time, together with reliable automated orientation determination from TEM-Kikuchi patterns. This has been used to determine misorientation angles at 90 degree domain boundaries and thus local c/a ratios. The sources of orientation noise/error and their effects on the misorientation angle data have been thoroughly analyzed and it is found that this gives a cosine distribution of misorientation angles about the mean with a characteristic width related to the width of the orientation noise distribution. In most cases, a good agreement is found between local c/a ratios and global measurements by X-ray diffraction, but some clear discrepancies have also been found suggesting that real local variations are present, perhaps as a consequence of compositional inhomogeneities.

EBSD characterization of carbide-carbide boundaries in WC-Co composites.

A sample of WC-6wt%Co was investigated for grain boundary character distribution and occurrence of coincidence site lattice (CSL) boundaries on a statistical basis. For this purpose orientation measurements of the grains were carried out using electron back-scattered diffraction (EBSD). The dominant misorientation relationships were determined by complementary EBSD data representation tools such as orientation maps, misorientation angle distribution histograms and the sectioned three-dimensional misorientation space. It was found that the grain boundary character distribution of the material is nearly random and the CSL boundaries are not present in statistically significant amounts. It was also found that the amount of binder phase does not play a role in the formation of special boundaries. The paper focuses on the methodology of characterizing grain boundaries in a hexagonal material using EBSD.