Chemical Kinetic Method for Active-Site Quantification in Fe-N-C Catalysts and Correlation with Molecular Probe and Spectroscopic Site-Counting Methods.

Mononuclear Fe ions ligated by nitrogen (FeNx) dispersed on nitrogen-doped carbon (Fe-N-C) serve as active centers for electrocatalytic O2 reduction and thermocatalytic aerobic oxidations. Despite their promise as replacements for precious metals in a variety of practical applications, such as fuel cells, the discovery of new Fe-N-C catalysts has relied primarily on empirical approaches. In this context, the development of quantitative structure-reactivity relationships and benchmarking of catalysts prepared by different synthetic routes and by different laboratories would be facilitated by the broader adoption of methods to quantify atomically dispersed FeNx active centers. In this study, we develop a kinetic probe reaction method that uses the aerobic oxidation of a model hydroquinone substrate to quantify the density of FeNx centers in Fe-N-C catalysts. The kinetic method is compared with low-temperature Mössbauer spectroscopy, CO pulse chemisorption, and electrochemical reductive stripping of NO derived from NO2- on a suite of Fe-N-C catalysts prepared by diverse routes and featuring either the exclusive presence of Fe as FeNx sites or the coexistence of aggregated Fe species in addition to FeNx. The FeNx site densities derived from the kinetic method correlate well with those obtained from CO pulse chemisorption and Mössbauer spectroscopy. The broad survey of Fe-N-C materials also reveals the presence of outliers and challenges associated with each site quantification approach. The kinetic method developed here does not require pretreatments that may alter active-site distributions or specialized equipment beyond reaction vessels and standard analytical instrumentation.

Level of knowledge and quality of life among Saudi caregivers of Parkinson's disease patients: A study from a tertiary hospital in Riyadh, Saudi Arabia.

Purpose: We aimed to assess the family caregivers' level of knowledge and attitudes about Parkison's disease (PD), identify factors affecting their knowledge, evaluate their quality of life (QoL) and factors influencing it and to define the effect of PD on activities of daily living (ADLs) of PD patients. Method: We developed and validated a questionnaire to assess the level of knowledge and attitudes of family caregivers toward PD, effects of PD on caregivers' QoL as well as its effects on activities of daily living (ADLs) of patients from the caregivers' perspective. A scoring system was utilized and SPSS was used to evaluate the differences in responses between the groups; p < 0.05 indicated statistical significance. Results: 69 caregivers and their corresponding patients were included in the study. Family caregivers had a low level of knowledge, as reflected by a mean score of 3.45 out of 8. However, 62.3% were aware of all medications used by their patients. Additionally, the level of knowledge was associated with caregivers' gender as 57.1% of the female caregivers had medium PD knowledge scores while 58.5% of the male had low scores (p = 0.038). The level of knowledge was also associated with daily caregiving hours as only 44.5% of caregivers whom spending 0-5 h/day had medium and high knowledge scores while greater proportions with same scoring levels were found among those providing care > 5 h/day (75.0% in > 5-10 hrs; 52.4% in > 10-24 hrs; p = 0.024). Most caregivers confirmed their QoL had declined, yet the male caregivers had better QoL than females (p = 0.026). Longer caregiving time was associated with decline (p = 0.016) and severe effect on QoL of caregivers (p = 0.04). Conclusion: Caregivers of PD patients had a low level of knowledge. Female caregivers had significantly higher level of PD knowledge than their male counterparts. Low level of PD knowledge was significantly associated with shorter caregiving time per day. Longer caregiving time was significantly associated with a decline in caregivers' QoL. Increasing awareness and knowledge among caregivers is necessary to ensure better treatment outcomes and improve the QoL of both caregivers and patients.

Prevalence of post-COVID symptoms of obsessive-compulsive disorder in Saudi Arabia.

OBJECTIVES: To determine the prevalence of Obsessive-Compulsive Disorder (OCD) symptoms in patients who have survived COVID-19. METHODS: The study used an observational cross-sectional design between July and October 2021. The target population was adult patients who had confirmed COVID-19 infection prior to joining the study, OCD symptoms were assessed using the Arabic OCD scale created by Abohendy and colleagues, which included 83 questions covering 12 different domains and was administired online. RESULTS: A total of 356 patients were included in the analysis. Approximately 9.0% and 1.7% of the patients had a history of psychiatric disease and OCD diagnosis (respectively). The total symptom score was 32.8%. The most frequently reported domains were rumination of ideas (55.5%), re-checking compulsions (37.0%), and slowness (34.0%), while the least frequently reported domains included obsessive impulses (26.3%), obsessive images (26.5%), and religious compulsions (26.8%). Unlike other domains, the purity and cleanliness compulsions scores were significantly higher than the scale reference population. A higher total symptom score was observed in psychiatric patients (p=0.004) and, to a lesser extent, in OCD patients (p=0.250). CONCLUSION: Overall, OCD symptoms, including cleanliness and fear of disease obsessions, tend to be higher in psychiatric and OCD patients, these findings are valuable for future studies.

Molecular Catalyst Synthesis Strategies to Prepare Atomically Dispersed Fe-N-C Heterogeneous Catalysts.

We report a strategy to integrate atomically dispersed iron within a heterogeneous nitrogen-doped carbon (N-C) support, inspired by routes for metalation of molecular macrocyclic iron complexes. The N-C support, derived from pyrolysis of a ZIF-8 metal-organic framework, is metalated via solution-phase reaction with FeCl2 and tributyl amine, as a Brønsted base, at 150 °C. Fe active sites are characterized by 57Fe Mössbauer spectroscopy and aberration-corrected scanning transmission electron microscopy. The site density can be increased by selective removal of Zn2+ ions from the N-C support prior to metalation, resembling the transmetalation strategy commonly employed for the preparation of molecular Fe-macrocycles. The utility of this approach is validated by the higher catalytic rates (per total Fe) of these materials relative to established Fe-N-C catalysts, benchmarked using an aerobic oxidation reaction.

Zeolite NPO-Type Azolate Frameworks.

Three-membered rings (3-rings) are an important structural motif in zeolite chemistry, but their formation remains serendipitous in reticular chemistry when designing zeolitic imidazolate frameworks (ZIFs). Herein, we report a design principle for constructing four new ZIFs, termed ZIF-1001 to -1004, from tetrahedral ZnII centers (T), benzotriazolate (bTZ), and different functionalized benzimidazolates (RbIM) that adopt a new zeolite NPO-type topology built from 3-rings. Two factors were critical for this discovery: i) incorporating the bTZ linker within the structures formed 3-rings due to a ∠(T-bTZ-T) angle of 120-130° reminiscent of the ∠(Ge-O-Ge) angle (130°) observed in germanate zeolite-type structures having 3-rings; and ii) RbIM guided the coordination chemistry of bTZ to bind preferentially in an imidazolate-type mode. This series' ability to selectively capture CO2 from high-humidity flue gas and trap ethane from tail gas during shale gas extraction was demonstrated.

High dose vs. low dose oxytocin for labor augmentation: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVES: To compare the safety and efficacy between high dose and low dose oxytocin administration for labor augmentation. METHODS: We searched for the available studies during March 2020 in PubMed, Cochrane Library, Scopus, and ISI Web of science. All randomized clinical trials (RCTs) that assessed safety and efficacy of high dose vs. low dose oxytocin for labor augmentation were considered. The extracted data were entered into RevMan software. Dichotomous and continuous data were pooled as odds ratio (OR) and mean difference (MD) respectively, with the corresponding 95% confidence intervals (CI). Our main outcomes were cesarean delivery rate, spontaneous vaginal delivery rate, uterine hyperstimulation and tachysystole, and labor duration from oxytocin infusion. RESULTS: Eight RCTs with 3,154 patients were included. High dose oxytocin did not reduce cesarean delivery rate compared to low dose oxytocin (OR=0.76, 95% CI [0.52, 1.10], p=0.15). After solving the reported heterogeneity, high dose oxytocin did not increase the rate of spontaneous vaginal deliveries vs. low dose oxytocin (OR=1.06, 95% CI [0.84, 1.32], p=0.64). Low dose oxytocin was linked to a significant decline in uterine hyperstimulation and tachysystole (p>0.001). A reduction in labor duration was found in high dose oxytocin group over low oxytocin regimen (MD=-1.02 h, 95% CI [-1.77, -0.27], p=0.008). CONCLUSIONS: We found no advantages for high dose oxytocin over low dose oxytocin in labor augmentation except in reducing labor duration. Low dose oxytocin is safer as it decreases the incidence of uterine hyperstimulation and tachysystole. More trials are needed to confirm our findings.

Case study-based systematic review of literature on lymphoma-associated cardiac tamponade.

This study aimed to compile all the relevant studies of patients presenting with pericardial tamponade before or after diagnosis of lymphoma, describe the clinical presentations of patients with lymphoma and cardiac tamponade, and assess the difference in overall survival based on the timing of cardiac tamponade diagnosis. A comprehensive search strategy was conducted in the following databases: PubMed and Cochrane Library, using the following keywords: Lymphoma AND Cardiac Tamponade. The criteria for eligibility included cases with a confirmed diagnosis of lymphoma and cardiac tamponade, human studies, and publications in English language. The statistical analysis was performed using IBM Statistical Package for Social Sciences (SPSS) version 20. We included 48 research articles (n = 52 cases) with adequate reporting of measured outcomes. The median age of the patients was 52 (9-94) years. Only 6 patients were noted to have primary cardiac lymphoma, while the majority of cases were considered to have secondary cardiac lymphoma (88.5%). According to the data on the type of lymphoma reported through cytology and immunohistochemistry, 49 patients were diagnosed with non-Hodgkin lymphoma, and of these cases the most common subtype was large B-cell lymphoma (42.9%). Overall, the average duration of illness was 14 ± 23 days. A total of 13 patients had distant heart sounds, 12 cases were noted to be hypotensive, and 13 subjects were found to have increased jugular venous pressure. Our retrospective study demonstrated that most patients presented with pericardial tamponade after lymphoma diagnosis, and those were mostly secondary cardiac lymphoma of the non-Hodgkin type with large B-cell as the most common subtype. Dyspnoea, oedema, and constitutional symptoms were the most common presenting signs. The median overall survival of patients with lymphoma and cardiac tamponade is 4 months, with no significant difference in mortality in the presentation timing before and after the diagnosis of lymphoma.

Efficacy and Safety of Intravenous Tramadol versus Intravenous Paracetamol for Relief of Acute Pain of Primary Dysmenorrhea: A Randomized Controlled Trial.

INTRODUCTION: Many pharmaceutical, surgical, and complementary medical interventions are used for primary dysmenorrhea treatment. However, no consensus has been reached about the most effective intervention. OBJECTIVE: To compare the efficacy and safety of IV tramadol versus IV paracetamol in relieving acute pain of primary dysmenorrhea. METHODS: This randomized controlled trial was conducted in a tertiary referral hospital and included 100 patients between 18 and 35 years old diagnosed with primary dysmenorrhea. Patients received either 1-g paracetamol or 100-mg tramadol in 100-mL normal saline as an IV infusion over 10 min. Pain intensity was measured by using a visual analog scale at 15, 30, 60 min, and 2 h. We recorded drug side effects and requirements for rescue analgesics. RESULTS: Pain scores were significantly lower in the tramadol group compared with the paracetamol group at 15, 30, 60 min, and 2 h (p < 0.001). Fewer patients in the tramadol group needed rescue analgesics compared with the paracetamol group (p = 0.04). No significant differences were reported in side effects between both groups. CONCLUSIONS: IV tramadol is superior to IV paracetamol in relieving acute pain of primary dysmenorrhea with a comparable side effect profile.

Electrocatalytic CO2 Reduction: From Homogeneous Catalysts to Heterogeneous-Based Reticular Chemistry.

CO2, emitted mainly from fossil fuel combustion, is one of the major greenhouse gases. CO2 could be converted into more valuable chemical feedstocks including CO, HCOOH, HCHO, CH3OH, or CH4. To reduce CO2, catalysts were designed and their unique characteristics were utilized based on types of reaction processes, including catalytic hydrogenation, complex metal hydrides, photocatalysis, biological reduction, and electrochemical reduction. Indeed, the electroreduction method has received much consideration lately due to the simple operation, as well as environmentally friendly procedures that need to be optimized by both of the catalysts and the electrochemical process. In the past few decades, we have witnessed an explosion in development in materials science-especially in regards to the porous crystalline materials based on the strong covalent bond of the organic linkers containing light elements (Covalent organic frameworks, COFs), as well as the hybrid materials that possess organic backbones and inorganic metal-oxo clusters (Metal-organic frameworks, MOFs). Owing to the large surface area and high active site density that belong to these tailorable structures, MOFs and COFs can be applied to many practical applications, such as gas storage and separation, drug release, sensing, and catalysis. Beyond those applications, which have been abundantly studied since the 1990s, CO2 reduction catalyzed by reticular and extended structures of MOFs or COFs has been more recently turned to the next step of state-of-the-art application. In this perspective, we highlight the achievement of homogeneous catalysts used for CO2 electrochemical conversion and contrast it with the advances in new porous catalyst-based reticular chemistry. We then discuss the role of new catalytic systems designed in light of reticular chemistry in the heterogeneous-catalyzed reduction of CO2.

Biliverdin Reductase A Attenuates Hepatic Steatosis by Inhibition of Glycogen Synthase Kinase (GSK) 3ß Phosphorylation of Serine 73 of Peroxisome Proliferator-activated Receptor (PPAR) α.

Non-alcoholic fatty liver disease is the most rapidly growing form of liver disease and if left untreated can result in non-alcoholic steatohepatitis, ultimately resulting in liver cirrhosis and failure. Biliverdin reductase A (BVRA) is a multifunctioning protein primarily responsible for the reduction of biliverdin to bilirubin. Also, BVRA functions as a kinase and transcription factor, regulating several cellular functions. We report here that liver BVRA protects against hepatic steatosis by inhibiting glycogen synthase kinase 3ß (GSK3ß) by enhancing serine 9 phosphorylation, which inhibits its activity. We show that GSK3ß phosphorylates serine 73 (Ser(P)73) of the peroxisome proliferator-activated receptor α (PPARα), which in turn increased ubiquitination and protein turnover, as well as decreased activity. Interestingly, liver-specific BVRA KO mice had increased GSK3ß activity and Ser(P)73 of PPARα, which resulted in decreased PPARα protein and activity. Furthermore, the liver-specific BVRA KO mice exhibited increased plasma glucose and insulin levels and decreased glycogen storage, which may be due to the manifestation of hepatic steatosis observed in the mice. These findings reveal a novel BVRA-GSKß-PPARα axis that regulates hepatic lipid metabolism and may provide unique targets for the treatment of non-alcoholic fatty liver disease.

Dual-degree MBBS-PhD programs in Saudi Arabia: A call for implementation.

Engaging medical students in scholarly research activities and producing clinically competent and research-oriented medical workforces are essential demands, particularly in developing countries. Dual-degree MD-PhD programs offer simultaneous rigorous education in medicine and research, and train its graduates (physician-scientists) to successfully catalyze translational research evolutions. Literature fundamentally identifies dual-degree MD-PhD programs as the single most important, well-established, popular and influential programs toward commencing physician-scientist professions. While the physician-scientist population is alarmingly vanishing in the West with ongoing efforts to reverse this undesired trend, such population is largely nonexisting, unfortunately to start with, in Saudi Arabia. This is simply because no single dual-degree MBBS-PhD program is yet established in Saudi Arabia. Herein, we call on the Saudi Higher Education bodies to implement dual-degree MBBS-PhD programs with anticipated generation of competent physician-scientists in Saudi Arabia. To the best of our knowledge, this is the first ever report to call for such innovative implementation.

Assessment of first-year medical students' perceptions of teaching and learning through team-based learning sessions.

Team-based learning (TBL) is an emerging teaching and learning strategy being employed in medical schools. The College of Medicine at Alfaisal University has adopted a TBL approach as an instructional method for first-year medical students. The aim of the present study was to describe the TBL method employed at Alfaisal University College of Medicine and to assess first-year medical students' perceptions of this learning modality for the anatomy- and physiology-based blocks/courses in organ systems form of curriculum. A five-point Likert scale questionnaire was structured based on Kirkpatrick's theory and assessed three major domains: reaction, learning, and behavior. Confirmatory factor analysis (CFA) and Cronbach's α-coefficient tests were used to assess the validity and reliability of the construct, respectively. CFA showed an adequate validity of the survey and Cronbach's α revealed an acceptable internal uniformity (0.69). A total of 185 respondents rated reaction, learning, and behavior toward introduction of TBL as 3.53 ± 1.01, 3.59 ± 1.12, and 3.57 ± 1.12, respectively. Excellent students rated TBL highly in all major domains compared with borderline students (reaction, behavior, and learning domains with P values of <0.049, <0.035, and <0.031, respectively). Students who had prior teamwork experience rated TBL higher in terms of their learning experience compared with those who were rarely involved in team work. This study demonstrated that Alfaisal University first-year medical students perceived TBL positively as a teaching and learning strategy for functional anatomy, and prior involvement in teamwork and academic performance correlates with higher ratings of TBL.

Research-oriented series: a portal into the culture of biomedical research for junior medical students at Alfaisal University in Saudi Arabia.

Student contributions to research have been shown to effectively reflect on their communication and critical thinking skills. Short-term research courses offer opportunities for medical students to advance their research experience in subsequent high-demanding long-term research opportunities. The purpose of the present study was to describe the development, implementation, and evaluation of a research-oriented series (ROS) on undergraduate students at Alfaisal University in Saudi Arabia. The ROS was designed to comprise eight sessions. Each session addressed core principles and the practice of research concepts and was based on theoretical morning sessions supplemented by afternoon practical sessions delivered by experienced senior medical students and faculty members. Students were assessed comprehensively by the end of the ROS. The series was conducted twice, and 35 students were involved each time. A total of 70 enrolled students (35 men and 35 women) with grade point averages of >3.5 and <3.5 were asked to fill out an anonymous, online, self-administered questionnaire assessing their perception of knowledge, skills, and confidence after attending the ROS and evaluating their senior peers. Ninety percent of the medical students responded to the online survey and rated the ROS highly in improving their research knowledge, skills, and confidence. Male students reported significant gains compared with their female peers (P<0.05). Grade point averages did not play a role in student gains after attending the ROS. Qualitative responses were in support of three recurring themes favoring the unique learning environment in the ROS. In conclusion, the ROS offers a short-term systematic approach to fundamental steps and concepts of biomedical research.

The interplay between academic performance and quality of life among preclinical students.

BACKGROUND: The high academic performance of medical students greatly influences their professional competence in long term career. Meanwhile, medical students greatly demand procuring a good quality of life that can help them sustain their medical career. This study examines validity and reliability of the tool among preclinical students and testifies the influence of their scholastic performance along with gender and academic year on their quality of life. METHODS: A cross sectional study was conducted by distributing World Health Organization Quality of Life, WHOQOL-BREF, survey among medical students of year one to three at Alfaisal University. For validity, item discriminate validity(IDV) and confirmatory factor analysis were measured and for reliability, Cronbach's α test and internal item consistency(IIC) were examined. The association of GPA, gender and academic year with all major domains was drawn using Pearson's correlation, independent samples t-test and one-way ANOVA, respectively. RESULTS: A total of 335 preclinical students have responded to this questionnaire. The construct has demonstrated an adequate validity and good reliability. The high academic performance of students positively correlated with physical (r = 0.23, p < 0.001), psychological health (r = 0.29, p < 0.001), social relations (r = 0.11, p = 0.03) and environment (r = 0.23, p < 0.001). Male student scored higher than female peers in physical and psychological health. DISCUSSION: This study has identified a direct relationship between the academic performance of preclinical students and their quality of life. CONCLUSION: The WHOQOL-BREF is a valid and reliable tool among preclinical students and the positive direction of high academic performance with greater QOL suggests that academic achievers procure higher satisfaction and poor achievers need a special attention for the improvement of their quality of life.

Effect of tidal volume on extravascular lung water content during one-lung ventilation for video-assisted thoracoscopic surgery: a randomised, controlled trial.

BACKGROUND: The use of low tidal volume during one-lung ventilation (OLV) has been shown to attenuate the incidence of acute lung injury after thoracic surgery. OBJECTIVE: To test the effect of tidal volume during OLV for video-assisted thoracoscopic surgery on the extravascular lung water content index (EVLWI). DESIGN: A randomised, double-blind, controlled study. SETTING: Single university hospital. PARTICIPANTS: Thirty-nine patients scheduled for elective video-assisted thoracoscopic surgery. INTERVENTIONS: Patients were randomly assigned to one of three groups (n = 13 per group) to ventilate the dependent lung with a tidal volume of 4, 6 or 8 ml  kg(-1) predicted body weight with I:E ratio of 1:2.5 and PEEP of 5 cm H2O. MAIN OUTCOME MEASURES: The primary outcomes were perioperative changes in EVLWI and EVLWI to intrathoracic blood volume index (ITBVI) ratio. Secondary outcomes included haemodynamics, oxygenation indices, incidences of postoperative acute lung injury, atelectasis, pneumonia, morbidity and 30-day mortality. RESULTS: A tidal volume of 4 compared with 6 and 8 ml  kg(-1) after 45 min of OLV resulted in an EVLWI of 4.1 [95% confidence interval (CI) 3.5 to 4.7] compared with 7.7 (95% CI 6.7 to 8.6) and 8.6 (95% CI 7.5 to 9.7) ml  kg(-1), respectively (P < 0.003). EVLWI/ITBVI ratios were 0.57 (95% CI 0.46 to 0.68) compared with 0.90 (95% CI 0.75 to 1.05) and 1.00 (95% CI 0.80 to 1.21), respectively (P < 0.05). The incidences of postoperative acute lung injury, atelectasis, pneumonia, morbidity, hospitalisation and 30-day mortality were similar in the three groups. CONCLUSION: The use of a tidal volume of 4 ml kg during OLV was associated with less lung water content than with larger tidal volumes of 6 to 8 ml kg(-1), although no patient developed acute lung injury. Further studies are required to address the usefulness of EVLWI as a marker for the development of postoperative acute lung injury after the use of a low tidal volume during OLV in patients undergoing pulmonary resection. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT01762709.

Undergraduate research: an innovative student-centered committee from the Kingdom of Saudi Arabia.

INTRODUCTION: Concern has been expressed in recent times whether medical schools have adapted sufficiently to cater for the increasing demand of physician-scientists. Studies have shown that research involvement at the undergraduate level is vital to accommodate this growing need. Enhanced communication skills, improved problem-solving abilities and better future employment opportunities are among the other many benefits of undergraduate research (UR). Herein, we report projects run by a unique student driven undergraduate research committee (URC) at Alfaisal University, Riyadh, Saudi Arabia aimed at providing the future generation of physicians training opportunities for pursuing a research intensive career. METHODS: The article describes the unique structure of the URC and provides an in-depth description of the various programs and activities used in promoting students' research activities. We analyzed students' perception of URC activities via a questionnaire and analyzed research-output of the first graduating batches through their publication record. RESULTS: Overall, more than 60% of the graduating students were involved in the various research programs offered by the URC and around 50% published in peer-reviewed journals with an average impact factor of 2.4. CONCLUSIONS: Research involvement by medical students is an essential need of the twenty-first century and models like URC could provide crucial platform for research training to the new generation of physician-scientists.

The summer premedical program for matriculating medical students: a student-led initiative.

The freshman academic year is one of the most difficult years that a medical student experiences in his/her academic life at a medical school. Freshmen are frequently faced with several challenges, such as adaptation to a new academic environment and its associated different methods of teaching, learning, skills, and assessment. The aim of this study was to describe a 4-wk innovative summer premedical program developed by senior medical students at the College of Medicine, Alfaisal University, in an attempt to improve/smooth the experience(s) of prospective freshmen. This report describes the objectives/strategies/methodologies used to tackle the top three identified freshman challenges, namely, 1) advancement of the academic/scholastic/educational background, 2) the development of college-required skills to succeed and excel in the freshman year, and 3) adaption to the college environment. At the end of the program, a survey was conducted to evaluate the effectiveness of the summer premedical program. Seventy-two students attended this program over the past three summers from 2010 to 2012, and twenty-nine students answered the survey with a response rate of 74.1%. Overall, >90% of the survey respondents reported an improvement in their understanding of basic medical science, integration, presentation skills, medical terminology, and junior-senior relationships. Furthermore, the survey highlighted the need for more focus on skills such as time management, participation in large-group discussions, and use of electronic resources, as >50% of respondents reported no improvement in these areas. In conclusion, this is the first report, to our knowledge, that describes a program developed by senior medical students to improve the experience of freshmen.

Disability attitudes in healthcare scale: translation and cross-cultural validation into Arabic using various medical samples.

PURPOSE: Cross-cultural adaptation of the Disability Attitudes in Health Care Scale (DAHCS) into Arabic to assess the attitude toward people with disabilities. The objective of this study was to: firstly, translate and cross-culturally adapt the DAHCS into Arabic and secondly, assess its psychometric properties. Further, the goal was to investigate bachelor medical students' and doctors' attitude toward people with disabilities and highlight the need to establish the scale's reliability and validity by employing various samples. METHODS: A convenience sample of 201 medical students and 105 doctors was used. Arabic DAHCS factors were extracted and confirmed by Exploratory Factor Analysis (EFA), and Confirmatory Factor Analysis (CFA). RESULTS: The findings revealed that medical professionals and students hold a positive attitude toward people with disabilities. The Mann-Whitney U and Kruskal-Wallis tests revealed no significant differences in the study's variables. EFA identified four factors. CFA showed a good fit to the model. Also, convergent and discriminant validity were achieved. Cronbach's Alpha and McDonald's Omega values for all factors were satisfactory. However, the study found a low value of Cronbach's Alpha and Omega for the fourth factor. CONCLUSIONS: The DAHCS was cross-culturally adapted into the Arabic language and its validity and reliability were achieved.

The Arabic version of the Disability Attitudes in Health Care Scale (DAHCS) demonstrated sufficient validity and reliability evidence to assess the Arabic-speaking healthcare students' and doctors' perceptions and attitudes towards people with disabilities.Those who educate medical students and provide rehabilitation training may find the DAHC useful.The DAHC is a specific scale to measure the attitude toward people with disabilities compared to other generic scales.

Mechanisms of Melanoma Progression and Treatment Resistance: Role of Cancer Stem-like Cells.

Melanoma is the third most common type of skin cancer, characterized by its heterogeneity and propensity to metastasize to distant organs. Melanoma is a heterogeneous tumor, composed of genetically divergent subpopulations, including a small fraction of melanoma-initiating cancer stem-like cells (CSCs) and many non-cancer stem cells (non-CSCs). CSCs are characterized by their unique surface proteins associated with aberrant signaling pathways with a causal or consequential relationship with tumor progression, drug resistance, and recurrence. Melanomas also harbor significant alterations in functional genes (BRAF, CDKN2A, NRAS, TP53, and NF1). Of these, the most common are the BRAF and NRAS oncogenes, with 50% of melanomas demonstrating the BRAF mutation (BRAFV600E). While the successful targeting of BRAFV600E does improve overall survival, the long-term efficacy of available therapeutic options is limited due to adverse side effects and reduced clinical efficacy. Additionally, drug resistance develops rapidly via mechanisms involving fast feedback re-activation of MAPK signaling pathways. This article updates information relevant to the mechanisms of melanoma progression and resistance and particularly the mechanistic role of CSCs in melanoma progression, drug resistance, and recurrence.