Buried interface molecular hybrid for inverted perovskite solar cells.

Perovskite solar cells with an inverted architecture provide a key pathway for commercializing this emerging photovoltaic technology because of the better power conversion efficiency and operational stability compared with the normal device structure. Specifically, power conversion efficiencies of the inverted perovskite solar cells have exceeded 25% owing to the development of improved self-assembled molecules1-5 and passivation strategies6-8. However, poor wettability and agglomeration of self-assembled molecules9-12 cause interfacial losses, impeding further improvement in the power conversion efficiency and stability. Here we report a molecular hybrid at the buried interface in inverted perovskite solar cells that co-assembled the popular self-assembled molecule [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphonic acid (Me-4PACz) with the multiple aromatic carboxylic acid 4,4',4″-nitrilotribenzoic acid (NA) to improve the heterojunction interface. The molecular hybrid of Me-4PACz with NA could substantially improve the interfacial characteristics. The resulting inverted perovskite solar cells demonstrated a record certified steady-state efficiency of 26.54%. Crucially, this strategy aligns seamlessly with large-scale manufacturing, achieving one of the highest certified power conversion efficiencies for inverted mini-modules at 22.74% (aperture area 11.1 cm2). Our device also maintained 96.1% of its initial power conversion efficiency after more than 2,400 h of 1-sun operation in ambient air.

High Performance Inverted RbCsFAPbI3 Perovskite Solar Cells Based on Interface Engineering and Defects Passivation.

Lead halide-based perovskites solar cells (PSCs) are intriguing candidates for photovoltaic technology due to their high efficiency, low cost, and simple fabrication processes. Currently, PSCs with efficiencies of >25% are mainly based on methylammonium (MA)-free and bromide (Br) free, formamide lead iodide (FAPbI3 )-based perovskites, because MA is thermally unstable due to its volatile nature and Br incorporation will induce blue shift in the absorption spectrum. Therefore, MA-free, Br-free formamidine-based perovskites are drawing huge research attention in recent years. The hole transporting layer (HTL) is crucial in fabricating highly efficient and stable inverted p-i-n structured PSCs by enhancing charge extraction, lowering interfacial recombination, and altering band alignment, etc. Here, this work employs a NiOx /PTAA bi-layer HTL combined with GuHCl (guanidinium hydrochloride) additive engineering and PEAI (phenylethylammonium iodide) passivation strategy to optimize the charge carrier dynamics and tune defects chemistry in the MA-free, Br-free RbCsFAPbI3 -based perovskite absorber, which boosts the device efficiency up to 22.78%. Additionally, the device retains 95% of its initial performance under continuous 1 sun equivalent LED light illumination at 45 °C for up to 500 h.

Parvimonas micra Bacteremia: A Rare Complication After Esophagogastroduodenoscopy for Upper Gastrointestinal Bleeding.

Parvimonas micra bacteremia is rarely encountered in clinical practice. When it is, patients usually have underlying periodontal disease or colorectal carcinoma. To the best of our knowledge, this is the first case of P. micra bacteremia in a patient without the predisposing risk factors listed above. We postulate that this occurred because of translocation across an interrupted gut-blood barrier in the setting of an acute upper gastrointestinal bleed. We present this case to highlight the importance of identifying and treating P. micra bacteremia because it can prevent commonly encountered sequelae of untreated bacteremia and improve outcomes.

Autologous Gastrointestinal Graft-vs-Host Disease in a Patient With Multiple Myeloma and Hematopoietic Stem Cell Transplantation.

Graft-vs-host disease (GVHD) of the gastrointestinal (GI) tract is notably a serious complication of allogeneic hematopoietic stem cell transplant (HSCT). However, GI GVHD has rarely been reported in autologous HSCT, and the pathophysiology remains unclear. Diagnosing GVHD after autologous HSCT requires a high level of clinical suspicion, given its nonspecific clinical presentation and endoscopic findings necessitating a histological diagnosis for confirmation. We present a case of autologous GVHD involving the GI tract in a patient with multiple myeloma who responded well to corticosteroids, highlighting the importance of early identification of this rare entity to initiate therapy and improve outcomes.

Suppressed Phase Segregation with Small A-Site and Large X-Site Incorporation for Photostable Wide-Bandgap Perovskite Solar Cells.

Wide-bandgap (WBG) perovskite solar cells (PSCs) have been widely used as the top cell of tandem solar cells. However, photoinduced phase segregation and high open-circuit voltage loss pose significant obstacles to the development of WBG PSCs. Here, a two-step small-size A-site and large-size X-site incorporation strategy is reported to modulate the lattice distortion and improve the film quality of WBG formamidinium-methylammonium (FAMA) perovskite films for photostable PSCs based on two-step deposition method. First, CsI with content of 0-20% is introduced to tune the lattice distortion and film quality of FAMA perovskite with a bandgap of 1.70 eV. Then, 4% RbI is incorporated to further modulate the perovskite growth and lattice distortion, leading to the suppression of photoinduced phase segregation in the resultant RbCsFAMA quadruple cation perovskites. As a result, the 20%CsI/4%RbI-doped device obtains a promising efficiency of 20.6%, and the corresponding perovskite film shows good photothermal stability. Even without encapsulation, the device can maintain 92% of its initial efficiency after 1000 h of continuous operation under 1 sun equivalent white light-emitting diode illumination.

Primary Gastrointestinal T-cell Lymphoma Presenting as Spontaneous Perforation Peritonitis.

Primary T-cell non-Hodgkin lymphoma (NHL) of the gastrointestinal tract (GIT) is a rare, poorly-characterized clinical entity. A well-known complication of intestinal NHL is perforation due to chemotherapy, but perforation as a presenting sign of GIT lymphoma is extremely rare. Here we present a case of spontaneous intestinal perforation secondary to primary intestinal T-cell lymphoma and highlight the importance of early recognition of this uncommon cause of perforation as a crucial step to ensure expedited hematology referral and initiation of appropriate treatment.

"Eat more protein, build more muscle": A grounded theory study of muscle-building behaviors among Canadian adolescents and young adults.

Unique risk factors for the development of muscle dissatisfaction and engagement in muscle-building behaviors have been described by theoretical frameworks and supported by empirical research. What remains unknown are the unique processes, including catalysts and facilitators, which underpin engagement in muscle-building behaviors. Therefore, this study used a grounded theory methodology to elucidate the process of engagement in muscle-building behaviors. Thirty-three individual semi-structured interviews with Canadian adolescents and young adults ages 16-30 years were conducted. Transcripts were analyzed using initial and focused coding to identify themes that explained the grounded theory. The core theme underpinning the grounded theory was balancing aesthetic, health, and functional goals in relation to participants' engagement in muscle-building behaviors. Participants described experiences that encompassed several unique phases of muscle-building engagement, including the initiation phase, beginner phase, preservation phase, and intensification phase. Participants also described unique methods of gathering information on muscle-building behaviors, and their own analysis and decision-making processes driving their behaviors. Findings from this study extend prior theory and research by conceptualizing a novel process theory of engagement in muscle-building behaviors among adolescent and young adults, resulting in important implications for research and practice.

Associations between social media use, fitness- and weight-related online content, and use of legal appearance- and performance-enhancing drugs and substances.

Prior research has documented the connection between social media use and engaging with fitspiration with body dissatisfaction, disordered eating behaviors, and various health risk behaviors (e.g., substance use). However, gaps remain in the knowledge base on whether social media use and engaging with fitness- and weight-related online content are associated with the use of legal appearance- and performance-enhancing drugs and substances (APEDS; e.g., whey protein), which was the aim of this study. Data from participants ages 16-30 years in Canadian Study of Adolescent Health Behaviors (N = 2731) were analyzed. Multiple modified Poisson regression analyses were conducted to determine the associations between hours per day of social media use and any engagement with fitness- and weight-related online content in the past 30 days and use of 10 different legal APEDS in the past 30 days. Greater time on social media was significantly associated with use of energy drinks and pre-workout drinks or powders in the past 30 days. Engaging with fitness- and weight-related online content was significantly associated with the use of caffeine, creatine monohydrate, pre-workout drinks or powders, probiotics, protein bars, and whey protein powders or shakes in the past 30 days. These findings expand prior research on the correlates of social media use and engagement with fitness- and weight-related online content among young people and have important implications for healthcare and public health professionals, as well as technology companies.

Prognostic value of normal exercise Tc-99m Sestamibi myocardial perfusion imaging in Karachi, Pakistan.

OBJECTIVE: To ascertain the hard event rate in local population with normal myocardial perfusion. METHODS: The study, which was conducted from August 2006 to January 2007, included 300 patients with normal exercise myocardial perfusion scan (MPS). Patients were categorized according to their pre-test probabilities for CAD. Patients with low pre-test probability for CAD were 136 and ranked in group A, while group B constituted 164 patients who had intermediate to high pre-test probability. RESULTS: During a follow-up of mean duration of 27 +/- 3 months, an overall hard cardiac event rate of 1.02% was noted. However, a statistically non-significant difference between the survival rates of low and high pre-test probability groups was also observed. CONCLUSION: The study demonstrated good prognosis for patients with normal exercise myocardial perfusion scan.

Knowledge and practice of healthy lifestyle and dietary habits in medical and non-medical students of Karachi, Pakistan.

OBJECTIVE: To objectively compare the differences in knowledge and practices regarding healthy lifestyle among medical and non-medical students of Karachi along with assessment of any perceived barriers. METHODS: This cross-sectional study included 350 students between ages 17-24 years from 6 private universities of Karachi--three medical and three non-medical Institutions. A self-reported questionnaire was employed to assess attitude and barriers to healthy practices among the simple random selection of students. RESULTS: On a 10-point scale, the average knowledge score of students on general and clinical nutritional knowledge was 5.7 +/- 1.51 and 4.4 +/- 1.77, respectively and the difference was statistically significant (p < 0.01). Conversely the diet and lifestyle score (85-point scale) among medical (41.3) and non medical students (40.8) was not significant (p = 0.646). There was no difference between the perception of medical and non-medical students regarding 'work-related stress' in their life. 'Lack of time' was cited as the most important reason for skipping meals and as a barrier to exercising regularly among both groups. CONCLUSION: The knowledge, attitudes and practices of medical students in Karachi suggest that superior knowledge about healthy lifestyle does not necessarily result into better practices.

Synthesis of ZnO/Fe3O4/rGO nanocomposites and evaluation of antibacterial activities towards E. coli and S. aureus.

Antibacterial activity of nanoparticles (NPs) and nanocomposites (NCs) has received wide spread attention in biomedical applications. In this direction, the authors prepared zinc oxide (ZnO), iron oxide (Fe3O4), and their composite including reduced graphene oxide (rGO) by hydrothermal method. The structural and microstructural properties of the synthesised NPs and NCs were investigated by XRD, FT-IR, UV-Vis, TGA, and TEM analysis. PEG-coated ZnO and Fe3O4 form in hexagonal wurtzite and inverse spinel structures, respectively. ZnO forms in rod-shaped (aspect ratio of ∼3) morphology, whereas well-dispersed spherical-shaped morphology of ∼10 nm is observed in Fe3O4 NPs. The ZnO/Fe3O4 composite possesses a homogeneous distribution of above two phases and shows a very good colloidal stability in aqueous solvent. These synthesised particles exhibited varying antibacterial activity against gram-positive strain Staphylococcus aureus (S. aureus) and gram-negative strain Escherichia coli (E. coli). The nanocomposite exhibits a better cidal effect on E. coli when compared to S. aureus when treated with 1 mg/ml concentration. Further, the addition of rGO has intensified the anti-bacterial effect to a much higher extent due to synergistic influence of individual components.

Nickel Toxicity Induced Changes in Nutrient Dynamics and Antioxidant Profiling in Two Maize (Zea mays L.) Hybrids.

Abstract: Nickel (Ni) is among the essential micronutrient heavy metals utilized by plants. However, an elevated level of Ni causes serious concerns for plants' physiology and their survival. This study evaluated the mechanisms influencing the growth, physiology, and nutrient dynamics in two commercial maize hybrids (Syngenta and Pioneer) exposed to Ni treatments in hydroponics nutrient solution (NS). Seedlings were raised in plastic trays with quartz sand, and subsequently transferred to Hoagland's NS at the two leaves stage. After three days of transplantation, Ni levels of 0, 20, and 40 mg L-1 were maintained in the nutrient solution. After 30 days of Ni treatments, seedlings were harvested and different growth, physiological, and nutrient concentrations were determined. The results showed that with increasing Ni concentration, the growth of maize hybrids was significantly reduced, and the maize hybrid, Pioneer, showed significantly higher growth than that of Syngenta at all levels of Ni. Higher growth in Pioneer is ascribed to elevated levels of antioxidant enzymes (SOD, CAT, GR, APX, and POX), lower damage to cellular membranes (i.e., higher MSI and lower MDA), and higher tissue nutrient concentrations (N, P, K, Ca, Mg, Fe, Mn, Zn, and Cu). Furthermore, the maize hybrids showed a difference in nutrient translocation from root to shoot which could be one of the factors responsible for differential response of these hybrids against Ni treatments.

HIV risk in Karachi and Lahore, Pakistan: an emerging epidemic in injecting and commercial sex networks.

The objective of this study was to measure HIV prevalence and risk behaviour in injecting drug users (IDUs), male sex workers (MSWs), Hijras (transgenders), female sex workers (FSWs) and male truckers in Karachi and Lahore, Pakistan. The design was a linked-anonymous cross-sectional study of individuals identified at key venues or through peer referral. Approximately 400 respondents in each group (200 for Hijras) responded to a standardized questionnaire and were tested for HIV antibodies at each site. In Karachi, 23% of IDUs and 4% of MSWs were HIV positive, and HIV-positive individuals were identified in all risk groups in at least one city. Two-thirds of all IDUs used a shared needle in the previous week, and unprotected commercial sex activity with men and women was high. The HIV epidemic has entered IDU and male and female commercial sex networks in Karachi and Lahore. Targeted intervention services must be scaled up and risk group surveillance intensified.

Quantitative evaluation of salivary gland dysfunction after radioiodine therapy using salivary gland scintigraphy.

AIM: The most frequent non-thyroidal complication of high-dose (131)I therapy for thyroid carcinoma is salivary gland dysfunction, which may be transient or permanent. In this study, we assessed radioiodine-induced permanent salivary gland dysfunction using quantitative salivary gland scintigraphy. METHODS: Salivary scintigraphy was performed with (99m)Tc-pertechnetate on 50 thyroid carcinoma patients who had been given radioiodine for thyroid ablation; 20 normal subjects were imaged as the control population. Dynamic scintigraphy was performed and time-activity curves for four major salivary glands were generated. The glandular functional parameters maximum secretion, time at maximum count and uptake ratio of the parotid and submandibular glands were calculated. Correlation of the administered dose and subjective symptoms with findings of salivary gland scintigraphy was evaluated. RESULTS: The maximum secretion and uptake ratio were decreased in 46% and 42% of patients who received radioiodine therapy, respectively. Salivary gland dysfunction correlated well with the administered dose. The parotid glands were more affected than the submandibular glands. Fifty-two per cent of patients were symptomatic, 69.23% of whom showed salivary gland dysfunction. CONCLUSION: Parenchymal damage to the salivary glands induced by radioactive iodine treatment can be evaluated by salivary gland scintigraphy. The impairment was worse in parotid glands and increased with the total dose. The maximum secretion and uptake ratio were found to be sufficiently sensitive to distinguish the severity of the damage.