Investigating the Effect of Carbon Nanotube Diameter and Wall Number in Carbon Nanotube/Silicon Heterojunction Solar Cells

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).Suspensions of single-walled, double-walled and multi-walled carbon nanotubes (CNTs) were generated in the same solvent at similar concentrations. Films were fabricated from these suspensions and used in carbon nanotube/silicon heterojunction solar cells and their properties were compared with reference to the number of walls in the nanotube samples. It was found that single-walled nanotubes generally produced more favorable results; however, the double and multi-walled nanotube films used in this study yielded cells with higher open circuit voltages. It was also determined that post fabrication treatments applied to the nanotube films have a lesser effect on multi-walled nanotubes than on the other two types

High performance ternary solar cells based on P3HT:PCBM and ZnPc-hybrids

Single walled carbon nanotubes (SWCNTs) and reduced graphene oxide (rGO) covalently and non-covalently functionalised by zinc phthalocyanine (ZnPc) were added to P3HT:PCBM blend in order to investigate the effects of these hybrid materials on P3HT:PCBM organic solar cell performance. Adding a small amount of these hybrids to P3HT:PCBM blend does not significantly alter the absorption spectra of the latter nor its structure. ZnPc–rGO and ZnPc–SWCNT hybrid features have appeared on the P3HT:PCBM surface morphology as verified by SEM and AFM images. However these hybrid materials have caused significant effects on the electrical properties of the studied blends. An increase of about two orders of magnitudes has been observed in the electrical conductivity. Space charge limited conduction theory was employed to investigate the charge carriers' mobility whereas a thermionic emission model was used to evaluate the recombination rate based on an estimated diode ideality factor. Solar cell devices based on P3HT:PCBM:ZnPc–SWCNTs-co bonded have demonstrated best device performance with PCE of 5.3%, Jsc of 12.6 mA cm−2, Voc of 0.62 V and FF of 68%. A reference device based on bare P3HT:PCBM blend has exhibited PCE of just under 3.5%, Jsc of 9.3 mA cm−2, Voc of 0.62 V and FF of 60%

Occupational Therapy Goal Achievement for People with Stroke: A Retrospective Study

Background/Aims. The process of occupational therapy services starts with assessing the occupational performance problems, setting goals, and implementing various intervention strategies to achieve the goals. The aim of this study was to assess the extent of achieving occupational therapy goals for people with stroke and categorize the goals according to the aspects of the domain of occupational therapy. Methods. A cross-sectional retrospective study design was used. People with stroke receiving rehabilitation services at King Abdulaziz Medical City (KAMC) were the target of this study. Data about the extent of achieving occupational therapy goals were collected using the Goal Attainment Scaling (GAS). Results. Of the 100 medical records of people with stroke included in this study, only 30% of the goals were functional. Only 54% of the goals were achieved. No association was found between the number of achieved goals and variables such as age, gender, type of stroke, and stroke hemisphere/side. Conclusion. People with stroke included in this study have not shown significant progress toward achieving their therapy goals. As for clinical practice, this study could guide therapists in the future to improve the process of achieving their patients’ goals

Use of carbon nanotubes (CNTs) with polymers in solar cells

There is a clear need to make energy cheap, readily accessible and green, while ensuring its production does not contribute to further climate change. Of all the options available, photovoltaics offer the highest probability of delivering a meaningful and sustainable change in the way society produces its energy. One approach to the development of such photovoltaics involves the use of polymers. These systems offer the advantages of cheap production, flexibility (and hence a range of deployment opportunities) and tunability of light absorption. However, there are issues with polymer-based photovoltaic systems and one significant effort to improve these systems has involved the use of carbon nanotubes (CNTs). This review will focus on those efforts. CNTs have been used in virtually every component of the devices to help charge conduction, improve electrode flexibility and in some cases as active light absorbing materials

Tenofovir in the treatment of naïve and refractory chronic Hepatitis B: A single center experience in Saudi Arabia

Background/Aims: Tenofovir disoproxil fumarate (TDF) is a nucleotide analog used in the treatment of chronic hepatitis B (CHB) infection. This study evaluated the efficacy of TDF in achieving undetectable HBV DNA after 48 weeks of treatment in a Saudi cohort of CHB patients. Patients and Methods: This retrospective study included patients treated at a tertiary care center in Saudi Arabia from January 2009 to December 2012. Of the 68 eligible patients, 51 were treatment naïve and 17 were treatment-refractory. Twenty-three patients tested positive for HBeAg. The remaining 45 patients were HBeAg-negative. Results: The mean HBV DNA viral load decreased from 95 million IU/mL at baseline to 263 IU/mL after 48 weeks of treatment (P < 0.001). Overall, 62% of patients achieved a complete virological response (CVR) and 37% a partial virological response (PVR). Respective CVR and PVR rates according to subgroup were: HBeAg-positive (21.7% and 78.3%) and HBeAg-negative (84.4% and 15.6%). At 48 weeks, HBV DNA was undetectable in 66.7% of treatment-naÏve and 53% of treatment-refractory patients (P = 0.3). Seroconversion occurred in 13 (57%) of HBeAg-positive patients. Two (3%) of the HBeAg-negative patients lost HBsAg at follow up. Mean alanine aminotransferase decreased significantly from 134 U/L before treatment to 37 U/L at 48 weeks (P < 0.001). Significant adverse events were not encountered during the study period. Conclusion: Forty-eight weeks of treatment with TDF reduced HBV DNA to undetectable levels in more than half of our patients regardless of whether they were treatment-naïve or refractory. HBeAg-negative (vs positive) patients experienced a better response rate

Multiple Sclerosis Diagnosis Using Machine Learning and Deep Learning: Challenges and Opportunities

Multiple Sclerosis (MS) is a disease that impacts the central nervous system (CNS), which can lead to brain, spinal cord, and optic nerve problems. A total of 2.8 million are estimated to suffer from MS. Globally, a new case of MS is reported every five minutes. In this review, we discuss the proposed approaches to diagnosing MS using machine learning (ML) published between 2011 and 2022. Numerous models have been developed using different types of data, including magnetic resonance imaging (MRI) and clinical data. We identified the methods that achieved the best results in diagnosing MS. The most implemented approaches are SVM, RF, and CNN. Moreover, we discussed the challenges and opportunities in MS diagnosis to improve AI systems to enable researchers and practitioners to enhance their approaches and improve the automated diagnosis of MS. The challenges faced by automated MS diagnosis include difficulty distinguishing the disease from other diseases showing similar symptoms, protecting the confidentiality of the patients&rsquo; data, achieving reliable ML models that are also easily understood by non-experts, and the difficulty of collecting a large reliable dataset. Moreover, we discussed several opportunities in the field such as the implementation of secure platforms, employing better AI solutions, developing better disease prognosis systems, combining more than one data type for better MS prediction and using OCT data for diagnosis, utilizing larger, multi-center datasets to improve the reliability of the developed models, and commercialization

Implication of MAPK, Lipocalin-2, and Fas in the protective action of liposomal resveratrol against isoproterenol-induced kidney injury

Background and Objective: Isoproterenol (ISO) is a non-selective β-adrenergic receptor agonist. It can be used to treat bradycardia and cardiogenic shock. Despite its usefulness, the overstimulation of β-receptors by ISO can cause “cardiorenal syndrome,” a term used to describe heart and kidney damage. Resveratrol (RES), a natural polyphenol, has marked anti-inflammatory and antioxidant activities. The present work was designed to study the protective efficacy of liposomal resveratrol (L-RES) against ISO-induced kidney injury. Materials and Methods: The kidney injury was induced in rats by administering ISO (50 mg/kg, s.c.) twice a week for 2 weeks. RES and L-RES were administered at a dose (20 mg/kg/ day, p.o.) along with ISO for 2 weeks. Inflammatory and apoptotic biomarkers were analyzed, which were validated using histochemical analysis. Results: ISO caused renal dysfunction, which manifested as elevated urea, creatinine and uric acid, besides cystatin c and MAPK protein overexpression. In addition, ISO induced gene expression of Fas and lipocalin-2 and provoked genomic DNA fragmentation in renal tissues as compared with the control group. Histological examination confirmed morphological alterations of the kidney tissues obtained from the ISO group. Concurrent treatment of either RES or L-RES with ISO significantly ameliorated kidney damage as demonstrated by the improvement of all measured parameters with the best results for L-RES. The histopathological findings were correlated with the above biochemical parameters. Conclusion: L-RES could be a promising approach for the prevention of kidney injury induced by ISO, most likely via the downregulation of MAPK, cystatin c, Fas, and lipocalin-2

Causes and outcomes of ICU hospitalisations in patients with pulmonary arterial hypertension

Rationale Pulmonary arterial hypertension (PAH) is a rare disease characterised by limited survival despite remarkable improvements in therapy. The causes, clinical burden and outcomes of patients admitted to the intensive care unit (ICU) remain poorly characterised. The aim of this study was to describe patient characteristics, causes of ICU hospitalisation, and risk factors for ICU and 1-year mortality. Methods Data from patients enrolled in the Johns Hopkins Pulmonary Hypertension Registry were analysed for the period between January 2010 and December 2020. Clinical, functional, haemodynamic and laboratory data were collected. Measurements and main results 102 adult patients with 155 consecutive ICU hospitalisations were included. The leading causes for admission were right heart failure (RHF, 53.3%), infection (17.4%) and arrhythmia (11.0%). ICU mortality was 27.1%. Mortality risk factors included Na <136 mEq·mL−1 (OR: 3.10, 95% CI: 1.41–6.82), elevated pro-B-type natriuretic peptide (proBNP) (OR: 1.75, 95% CI: 1.03–2.98), hyperbilirubinaemia (OR: 1.40, 95% CI: 1.09–1.80), hyperlactaemia (OR: 1.42, 95% CI: 1.05–1.93), and need for vasopressors/inotropes (OR: 5.29, 95% CI: 2.28–12.28), mechanical ventilation (OR: 3.76, 95% CI: 1.63–8.76) and renal replacement therapy (OR: 5.57, 95% CI: 1.25–24.76). Mortality rates at 3, 6 and 12 months were 17.5%, 27.6% and 39.0%, respectively. Connective tissue disease-associated PAH has lower 1-year survival compared to idiopathic PAH (51.4% versus 79.8%, log-rank test p=0.019). Conclusions RHF is the most common cause for ICU admission. In-hospital and 1-year mortality remain exceedingly high despite improved ICU care. Recognising specific risk factors on admission can help identifying patients at risk for poor outcomes