Velocity-slip boundary conditions and shape factor effects on MHD hybrid nanofluid flow via converging/diverging channels

DATA AVAILABILITY : No data was used for the research described in the article.The most important objective of this research-work is to investigate the impacts of velocity-slip boundary conditions and shape factor of solid nanoparticles on the hydrodynamic behavior of the nonlinear problem of MHD Jeffery–Hamel hybrid nanofluid flow where the mixture H2O C2H6O2 (50% 50%) was utilized as a base fluid. Using appropriate velocity transformations, the basic partial differential equations arising from mathematical modeling are transformed into non-linear ordinary differential equations. Afterwards, the determined nonlinear equation was numerically solved utilizing Runge-Kutta-Fehlberg 4th–5th order approach featuring shooting technique and analytically with the help of Duan–Rach Approach (DRA). The impact of active factors like Reynolds number, channel half-angle, Hartman number, base fluids nature, hybrid nanoparticles, velocity-slip boundary conditions, shape and Geometry of solid nanoparticles on hybrid nanofluid velocity and skin friction coefficient are visualized and investigated. The minimal local skin friction is found to be obtainable with the nanoparticles of Platelet form and second-order slip model where a reduction of 70% is gained compared to the local skin friction coefficient with spherical nanoparticles when the Hartmann number is higher. Results obtained also reveal that a higher reduction of 69% in local skin friction coefficient intensity is observed for both hybrid phase (Al2O3 Cu) and mixture base fluid (H2O C2H6O2) with second-order slip boundary condition model when Knudsen number Kn = 0,08. A comparison was made between the results obtained from this investigation in particular cases and the results obtained via the HAM-based Mathematica package for validation. Also, the obtained analytical DRA data are compared with numerical RKF45 data and the ones represented in the literature. The comparison revealed that the results match perfectly which justifies applicability, validity, and the higher exactness of the adopted Duan-Rach approach.http://www.elsevier.com/locate/jmmmam2024Mechanical and Aeronautical EngineeringSDG-09: Industry, innovation and infrastructur

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

Assessment of Healthcare Service Provision to Pediatric Patients With Chronic Diseases During the COVID-19 Lockdown

Background: The Coronavirus disease 2019(COVID-19) pandemic’s impact on essential health services is of great concern. The most important step in managing any patient with chronic disease is compliance with follow-up visits. Aim: This study aims to assess healthcare services during the period of the COVID-19 pandemic lockdown regarding chronic patient visits and care, as well as to assess patient satisfaction with the provision of healthcare services during the lockdown period. Methods: a cross-sectional study was performed at Cairo University Specialized Children Hospital, Egypt, through an interview questionnaire with the caregivers of chronic patients about the health care services throughout the COVID-19 pandemic from December 2020 to July 2021. Results:  More than 60% were satisfied with the healthcare service provision during the COVID-19 pandemic lockdown. Satisfaction toward medical sub-specialties was significantly higher than that of surgical ones. Patients who attended for follow-up markedly decreased during the lockdown.   Conclusion: During the COVID-19 pandemic, healthcare service provision was negatively affected. Follow-up of chronic patients and continued medical care were challenging points

Synthesis and in-vitro anti-proliferative with antimicrobial activity of new coumarin containing heterocycles hybrids

Abstract A series of new coumarin-N-heterocyclic hybrids, coumarin-quinolines 7a–e, coumarin-acridines 10b,c and coumarin-neocryptolepines 13b,c were synthesized and evaluated for their anticancer and antimicrobial activities. The structures of all synthesized hybrids were confirmed by FT-IR, 1H-NMR, 13C-NMR, and MS spectrometry. The anti-proliferative activity of hybrids 7a–e, 10c and 13c were bio-evaluated using MTT-assay against colon (CaCo-2), lung (A549), breast (MDA-MB-231), and hepatocellular carcinoma (HepG-2) human cancer cell lines using doxorubicin as a reference drug. The results demonstrated that, all hybrids displayed moderate to good anti-proliferative activity against the cell lines. The most active hybrids were 7a–d and 10c against CaCo-2 cancer cell line with IC50: 57.1, 52.78, 57.29, 51.95 and 56.74 µM, and selectivity index 1.38, 1.76, 2.6, 1.96 and 0.77; respectively. While, 7a,d were potent against A549 cancer cell line with IC50: 51.72, 54.8 µM and selectivity index 1.5, 0.67; respectively. Moreover, 7c showed the most potency against MDA-MB-231 cancer cell line with IC50: 50.96 µM and selectivity index 2.20. Interestingly, docking results revealed that binding energy of the current compounds showed marked affinity values ranging from -6.54 to -5.56 kcal with interactions with the reported key amino acid SER 79. Furthermore, the antimicrobial activity of the synthesized hybrids 7a–e, 10b,c, 13b and 13c were evaluated against Gram‐positive and Gram‐negative bacterial and fungal strains. The hybrids 10b, 13b, 10c, and 13c exhibited broad-spectrum antibacterial activity against E.coli, S. mutans, and S. aureus with MIC from 3.2 to 66 µM, this hybrids also displayed antifungal activity against C. albicans with MIC values ranging from 0.0011 to 29.5 µM. In-silico investigation of the pharmacokinetic properties indicated that tested hybrids had high GI absorption, low Blood Brain Barrier (BBB) permeability in addition to cell membrane penetrability

Non‐classical monocytes frequency and serum vitamin D3 levels are linked to diabetic foot ulcer associated with peripheral artery disease

Abstract Aims/Introduction Peripheral artery disease (PAD) serves as a risk factor for diabetic foot ulcers (DFUs). PAD pathology involves atherosclerosis and impaired immunity. Non‐classical monocytes are believed to have an anti‐inflammatory role. 1,25‐Dihydroxy vitamin D (vitamin D3) is claimed to have immune‐modulating and lipid‐regulating roles. Vitamin D receptor is expressed on monocytes. We aimed to investigate if circulating non‐classical monocytes and vitamin D3 were implicated in DFUs associated with PAD. Materials and Methods There were two groups of DFU patients: group 1 (n = 40) included patients with first‐degree DFUs not associated with PAD, and group 2 (n = 50) included patients with DFU with PAD. The monocyte phenotypes were detected using flow cytometry. Vitamin D3 was assessed by enzyme‐linked immunosorbent assay. Results DFU patients with PAD showed a significant reduction in the frequency of non‐classical monocytes and vitamin D3 levels, when compared with DFU patients without PAD. The percentage of non‐classical monocytes positively correlated with vitamin D3 level (r = 0.4, P < 0.01) and high‐density lipoprotein (r = 0.5, P < 0.001), whereas it was negatively correlated with cholesterol (r = −0.5, P < 0.001). Vitamin D3 was negatively correlated with triglyceride/high‐density lipoprotein (r = −0.4, P < 0.01). Regression analysis showed that a high vitamin D3 serum level was a protective factor against PAD occurrence. Conclusions Non‐classical monocytes frequency and vitamin D3 levels were significantly reduced in DFU patients with PAD. Non‐classical monocytes frequency was associated with vitamin D3 in DFUs patients, and both parameters were linked to lipid profile. Vitamin D3 upregulation was a risk‐reducing factor for PAD occurrence

Biomedical Promise of Aspergillus Flavus-Biosynthesized Selenium Nanoparticles: A Green Synthesis Approach to Antiviral, Anticancer, Anti-Biofilm, and Antibacterial Applications

This study utilized Aspergillus flavus to produce selenium nanoparticles (Se-NPs) in an environmentally friendly and ecologically sustainable manner, targeting several medicinal applications. These biosynthesized Se-NPs were meticulously characterized using X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, transmission electron microscope (TEM), and UV–visible spectroscopy (UV), revealing their spherical shape and size ranging between 28 and 78 nm. We conducted further testing of Se-NPs to evaluate their potential for biological applications, including antiviral, anticancer, antibacterial, antioxidant, and antibiofilm activities. The results indicate that biosynthesized Se-NPs could be effective against various pathogens, including Salmonella typhimurium (ATCC 14028), Bacillus pumilus (ATCC 14884), Staphylococcus aureus (ATCC 6538), Clostridium sporogenes (ATCC 19404), Escherichia coli (ATCC 8739), and Bacillus subtilis (ATCC 6633). Additionally, the biosynthesized Se-NPs exhibited anticancer activity against three cell lines: pancreatic carcinoma (PANC1), cervical cancer (Hela), and colorectal adenocarcinoma (Caco-2), with IC50 values of 177, 208, and 216 μg/mL, respectively. The nanoparticles demonstrated antiviral activity against HSV-1 and HAV, achieving inhibition rates of 66.4% and 15.1%, respectively, at the maximum non-toxic concentration, while also displaying antibiofilm and antioxidant properties. In conclusion, the biosynthesized Se-NPs by A. flavus present a promising avenue for various biomedical applications with safe usage

Phytochemical Analysis of <i>Centaurea calcitrapa</i> L. Aerial Flowering Parts Serial Solvent Extracts and Its Antibacterial and Antioxidant Activities

To evaluate the phytochemical composition, antibacterial, and antioxidant activity of successive extracts of Centaurea calcitrapa L. (C. calcitrapa) aerial flowering parts, they were assessed in vitro. Using a spectrophotometer, the sample absorbance at 517 nm was used to quantify the scavenging activity. The negative control was DPPH. In the current study, the diffusion using agar wells technique was adapted to measure antimicrobial activity. Phytochemical analysis was performed using the recommended standard procedures. The methanol extract of C. calcitrapa exhibited high levels of total phenolic acids expressed as gallic acid (GA), measured as (97.25 ± 0.73 mg GAE/g) content compared to the chloroform, acetyl acetate, and aqueous extracts (27.42 ± 0.29, 64.25 ± 0.96, and 17.25 ± 0.73 mg GAE/g), respectively. Additionally, the methanol extract had a higher total tannin (27.52 ± 0.53 mg TAE/g) content compared to the chloroform, ethyl acetate, and aqueous extracts (12.02 ± 0.55, 26.01 ± 0.81, and 7.35 ± 0.56 mg TAE/g), respectively, while the aqueous extract contains a lower percentage of flavonoids (141.10 ± 1.31 mg RTE/g) compared to the higher content achieved by the methanol extract (425.93 ± 1.27 mg RTE/g). The hydroxyl groups of the flavonoid and the phenolic compounds found in C. calcitrapa are essentially scavenging free radicals. Radical scavenging activity was highest in the methanol extract (IC50 = 2.82 μg/mL), aqueous extract (IC50 = 8.03 μg/mL), ethyl acetate extract (IC50 = 4.79 μg/mL), and chloroform extract (IC50 = 6.33 μg/mL), as compared to the standard scavenging activity (IC50 = 2.52 μg/mL). The antibacterial properties of C. calcitrapa against Gram-negative bacterial strains Klebsiella pneumoniae, Escherichia coli, Enterobacter aerogenes, and Acinetobacter baumanii, in addition to Gram-positive strains Staphylococcus haemolyticus, Enterococcus faecalis, and Staphylococcus aureus, revealed inhibition zone diameter. The findings of this investigation establish that the aerial flowering parts of C. calcitrapa have substantial antibacterial action against human infections, and the plant can serve as a significant antioxidant that can be employed to prevent and treat severe degenerative diseases brought on by oxidative stress. qPCR showed that C. calcitrapa extracts elevate both SOD1 and SOD2 (cellular oxidation markers) with remarkable folds (1.8-fold for SOD1 and SOD2) with ethyl acetate plant extract against ascorbic acid as a control. This result reflects that C. calcitrapa extracts have remarkable antioxidant activity

Global economic burden of unmet surgical need for appendicitis

Background There is a substantial gap in provision of adequate surgical care in many low- and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US $92 492 million using approach 1 and$73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was $95 004 million using approach 1 and$75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially

Global economic burden of unmet surgical need for appendicitis

Background There is a substantial gap in provision of adequate surgical care in many low- and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US $92 492 million using approach 1 and$73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was $95 004 million using approach 1 and$75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially