Helwan University
  • Cairo, Cairo, Egypt
Recent publications
Background Infection in arteriovenous fistula (AVF) is a common complication in patients with end-stage renal disease (ESRD) requiring dialysis. The standard management includes ligation of the AVF to prevent the progression of septicemia. Till now, there is limited evidence on the effectiveness and possibility of salvage of infected AVFs. Aim To evaluate the effectiveness and safety of salvage of infected mature autogenous AVF. Methods This prospective study was conducted at the Fayoum University Hospital from September 2015 to April 2023. We included patients with dysfunctional and functioning infected AVF. Patients with infected synthetic grafts and immature infected AVFs were excluded. We aimed to excise the infected part of the vein wall and surrounding tissues to restore fistula patent and functioning after direct vein repair. We followed-up with all patients for 1 year and examined the repaired AVFs for patency and the possibility of re-infection. Tissue cultures were obtained to identify the commonest responsible organism and the recommended antibiotics. Results A total of 46 patients with infected AVFs were included. At the end of the follow-up period, 11 patients were ligated, and 35 underwent AVF salvage procedures. 19 cases experienced some complications: 5 cases had hematoma required surgical intervention, 2 cases had hematoma managed conservatively, 2 patients had wound dehiscence, 3 patients required hybrid angioplasty for acute failed AVF, and 7 cases required angioplasty for failing AVF. Conclusion When performed correctly and with expert hands, salvage of infected mature AVFs seems possible with excellent efficacy and high patency for up to 1 year.
Background The purpose of this research was to inspect the tumor landscapes, surgical particulars, and survival distribution of patients of gastric gastrointestinal stromal tumors (GIST) that were surgically removed at the National Cancer Institute, Cairo University. Materials and methods Patients who submitted an application to our clinic and were ultimately diagnosed with gastric GIST were included in this retrospective analysis. Patients’ ages and sexes were recorded, as well as their original tumor sites, histological features, staging, treatments received, treatment methods, and survival rates. Results There were a total of 23 patients, with a female to male ratio of 1 : 3, who had a diagnosis of gastric GIST. They averaged 56 years of age. Tumor sizes, on average was 11.2 cm. In 18 (78.3%) cases, the tumor was located at the distal end, whereas in 5 (21.7%) cases it was located at the proximal end. 19 patients underwent first surgery, whereas only 5 got neoadjuvant treatment focused on the primary tumor. 17 (73.9%) individuals (73.9%) had sleeve gastrectomy, making it the most prevalent operation. 7 days was the typical duration of stay in the hospital. Two patients showed postoperative gastric leakage; the first was treated conservatively, while the second was treated surgically and resulted in a total gastrectomy. With regard to risk categorization, 10 (43.5%) patients had tumors with a high level of risk, 9 (39.1%) had tumors with an intermediate risk, whereas just 4 (17.4%) had tumors with a low risk (Table 3). 16 (69.6%) patients received supplemental targeted treatment. The median duration of patient follow-up was 42.6 months, and all patients were tracked. The cumulative overall survival at 5 years was 82.1%, while the cumulative disease-free survival was 65.4%. Conclusion For individuals who need their gastric GIST removed, extensive local resection that preserves the stomach yields excellent functional and oncological results.
Background Pancreatic fistula remains the most dangerous complication after pancreatoduodenectomy (PD). This study aimed to identify the operative risk factors for clinically relevant-postoperative pancreatic fistula (CR-POPF) after PD. Methods This prospective multicenter cohort study investigated the association between CR-POPF and operative risk factors in 107 patients who underwent PD at three tertiary centers from August 2017 to July 2022. Results The incidence of CR-POPF was 26.2%. With univariate analysis, soft pancreatic texture, pancreatic duct diameter (≤3 mm), right-sided pancreatic transection, absorbable suture, pancreatico-enteric anastomosis invagination technique, non-stented pancreatic drainage, internal pancreatic drainage, long anastomotic time (>40 min), and R1 resection margin were risk factors for CR-POPF. Multivariate analysis identified four independents risk factors for CR-POPF: (1) soft pancreatic texture (OR 0.219; 95% CI 0.061–0.792; P <0.021), (2) small main pancreatic duct diameter (OR 0.280; 95% CI 0.086–0.910; P <0.034), (3) right-sided pancreatic transection (OR 0.168; 95% CI 0.032–0.881; P <0.035), and (4) non-stented pancreatic drainage (OR 3.771; 95% CI 1.147–12.401; P <0.029). Conclusion The incidence of CR-POPF after PD is reduced significantly by left-sided pancreatic transection and pancreatic drainage. Soft pancreatic texture and small main pancreatic duct diameter are independent risk factors for CR-POPF, and clinically postoperative prophylactic measures should be implemented as soon as possible.
Objective This study aimed to investigate the combined effect of CYP3A5*3, CYP3A4*22, and POR*28 genetic polymorphisms on tacrolimus and cyclosporine dose requirements. Methods One hundred thirty renal transplant patients placed on either tacrolimus or cyclosporine were recruited, where the effect of CYP3A5*3, CYP3A4*22, and POR*28 genetic polymorphisms on their dose requirements were studied at days 14, 30, and 90 post-transplantations. Results The POR*28 allele frequency in the studied population was 29.61%. The tacrolimus dose-adjusted trough concentration ratio (C0/D) was significantly lower in the fast metabolizers group ( CYP3A5*1/POR*28(CT/TT ) carriers) than in the poor metabolizers group ( CYP3A5*3/*3/CYP3A4*22 carriers) throughout the study (14, 30, and 90 days) ( P = 0.001, <0.001, and 0.003, respectively). Meanwhile, there was no significant effect of this gene combination on cyclosporine C0/D. Conclusion Combining the CYP3A5*3, POR*28 , and CYP3A4*22 genotypes can have a significant effect on early tacrolimus dose requirements determination and adjustments. However, it does not have such influence on cyclosporine dose requirements.
In recent years, there has been a significant increase in the amount of healthcare data generated by patients, healthcare providers, and medical researchers. This data is often sensitive and contains personally identifiable information, making it critical to protect patient privacy while still enabling the sharing of data for research and healthcare purposes. In this chapter, we review recent advances in healthcare data privacy techniques, the privacy breaches from the unique identification of an individual or single/multiple attributes disclosure to the behavioral advertising privacy breaches. We will discuss the strengths and limitations of each approach and provide examples of how they have been applied in healthcare contexts. We also examine the ethical and legal considerations surrounding healthcare data privacy and the challenges of implementing these techniques in practice. Finally, we explore future directions for healthcare data privacy research.
Design codes disagree on the design of Concrete filled steel tubes (CFST). Thus, in this current study, a comparison between the main international design codes for the design of CFST is presented. The considered codes include: AIJ 1997, AISC, EC4, ECP (ECP 205-2007 in Design of steel structures. National research center for housing and construction, Cairo, Egypt). Concluding remarks are outlined and discussed.
Background : Neglected non-united lateral humeral condyle fractures in pediatrics are a probable cause of cubitus valgus deformity which is a disabling complication. The ideal management for this condition is still debatable. This study aimed to evaluate the reconstruction of a non-united lateral humerus condylar fracture complicated by cubitus valgus using a tricortical iliac crest graft in pediatric patients. Patients and methods : Twenty children suffering from cubitus valgus as a complication after a non-united fracture of the lateral humeral condyle were included in this study. They were managed by open reduction, screw fixation, and reconstruction by an autologous tricortical iliac bone graft. We compared the preoperative and postoperative range of motion of the elbow, alignment, and elbow function using the Mayo elbow performance index. Results : There was a statistically significant improvement in the elbow range of motion postoperatively, and there was a highly significant improvement regarding the elbow alignment and function. Conclusion : Open reduction, screw fixation, and reconstruction by the autologous tricortical iliac bone graft is an effective technique for the management of cubitus valgus due to neglected non-united lateral humeral condyle fractures in pediatrics.
Due to the exceptional property portfolio and technological applications of phase change materials, mostly chalcogens related to IV-VI and V2-VI3 families, which are in turn related to pnictogens (group V or 15) and chalcogens (group VI or 16), the nature of the unconventional chemical bonding in these materials has been debated for almost 70 years. This unconventional bond, which has been quoted in the literature as resonant, hypervalent, electron-rich multicenter, three-center-four-electron (3c-4e), and metavalent, is believed to be responsible for the exceptional properties of phase change materials. In the last decade, two bonding models, the metavalent and the electron-rich multicenter models, have competed to explain the nature of this unconventional bond, which we have here renamed as metavalent multicenter bond (MMB) for the sake of clarity. In this comprehensive work, we address the nature of MMB and propose that MMB is an electron-deficient multicenter bond (EDMB), related to the threecenter-two-electron (3c-2e) bond. For that purpose, we explore the pressure-induced mechanism of MMB formation in the some of the simplest possible systems, pnictogens (As, Sb, Bi) and chalcogens (Se, Te, Po), with density-functional theory calculations. In the way, we find that polonium is the only element among chalcogens and pnictogens with crystalline α and β structures already exhibiting MMBs at RP. We find that the mechanism of MMB formation in pnictogens (chalcogens) is comprised of three (two) stages, is similar to that of the EDMB formation in B2H6, in some Zintl phases, intermetallics, and cluster compounds, and in atomic/polymeric nitrogen and hydrogen at high pressures. On the other hand, the mechanism of EDMB formation is completely different from that of the 3c-4e bond formation in molecules. Finally, we propose the simplest geometries of EDMBs that can be found in solids along one, two, and three dimensions and comment on the validity of the doublet/octet rules in the hypercoordinated multicenter units with EDMBs.
Utilizing nanoparticles with a size of less than 100 nm, nanotechnology present an unheard of chance to create concentrated supplies of nutrients with increased absorption rates, effective use, and minimal losses. By encapsulating plant nutrients in nanoparticles, using a thin layer of nanomaterials to coat nutrients of plant, and distributing as nanosized emulsions, nanofertilizers are created. In plant leaves, nanopores and stomatal apertures enable the uptake of nanomaterials and their penetration inside leaves, increasing nutrient utilization efficiency (NUE). Through plasmodesmata, which are 50–60 nm-wide nanoscale passageways between cells, nutrients from nanofertilizers are transported and delivered to cells more efficiently. Field crops had higher yields (6–17%) and better nutritional quality thanks to nanofertilizers’ higher NUE and noticeably lower nutrient losses. Since the last few decades, nanotechnology has been widely applied in the global agricultural system. However, because of its toxicity and potentially harmful effects on both the environment and human health, it is still difficult to use nanotechnology in fertilizers. However, the use of nanoparticles as a tool may be advantageous for crops that are essential to agriculture. They have shown a variety of impacts on absorption, translocation, and morphological and physiological changes in different plant sections. The several agriculturally grown crops’ responses to different nanoparticles were dose-dependent and might differ from species to species. The uncontrolled deposition of metal-based nanoparticles in terrestrial ecosystems, particularly in agricultural systems, has significantly endangered the variety of beneficial microbial communities, including soil bacteria and fungi.
Dye-sensitized solar cells (DSSCs) are low-cost solar energy conversion devices with variable color and transparency advantages. DSSCs' potential power efficiency output, even in diffuse light conditions with consistent performance, allows them to be used in building-integrated photovoltaics (BIPV) window applications. Significantly, the development of bifacial DSSCs is getting significant scientific consideration. Triiodide/iodide (I 3 – /I – ) redox couple-mediated DSSCs require highly effective and stable electrocatalysts for I 3 ⁻ reduction to overcome their performance constraints. However, the commonly employed platinum (Pt) cathodes have restrictions on high price and unfavorable durability. Here, we report platinum nanoparticles (Pt NPs) incorporated into multiwalled carbon nanotubes (MWCNT) composites with lower Pt content as an efficient bifacial counter electrode (CE) material for DSSC applications. Pt NPs were homogenously decorated over the MWCNT surfaces using a simple polyol method at relatively low temperatures. CEs fabricated using Pt/MWCNT composites exhibited excellent transparency and power conversion efficiencies (PCE) of 6.92% and 6.09% for front and rear illumination. The results are expected to bring significant advances in bifacial DSSCs for real-world window applications.
Coccidiosis is the most prevalent disease-causing widespread economic loss among farm and domestic animals. Currently, several drugs are available for the control of this disease but resistance has been confirmed for all of them. There is an urgent need, therefore, for the identification of new sources as alternative treatments to control coccidiosis. The present work aimed to study the effect of the Persea americana extract (PAE) as an anti-coccidial, anti-oxidant, and anti-apoptotic modulator during murine intestinal Eimeria papillata infection. A total of 25 male mice were divided into five groups, as follows: Group1: Non-infected-non-treated (negative control), Group2: Non-infected-treated group with PAE (500 mg/kg b.w). Group3: Infected-non-treated (positive control), Group4: Infected-treated group with PAE (500 mg/kg b.w.), and Group5: Infected-treated group with Amprolium (120 mg/kg b.w.). Groups (3–5) were orally inoculated with 1 × 103 sporulated E. papillata oocysts. After 60 min of infection, groups (4 and 5) were treated for 5 consecutive days with the recommended doses of PAE and amprolium. The fact that PAE has an anti-coccidial efficacy against intestinal E. papillata infection in mice has been clarified by the reduction of fecal oocyst output on the 5th day post-infection by about 85.41%. Moreover, there is a significant reduction in the size of each parasite stage in the jejunal tissues of the infected-treated group with PAE. PAE counteracted the E. papillata-induced loss of glutathione peroxidase (GPx), superoxide dismutase (SOD), and total antioxidant capacity (TCA). E. papillata infection also induced an increase in the apoptotic cells expressed by caspase-3 which modulated after PAE treatment. Moreover, the mRNA expression of the goblet cell response gene, mucin (MUC2), was upregulated from 0.50 to 1.20-fold after treatment with PAE. Based on our results, PAE is a promising medicinal plant with anti-coccidial, anti-oxidant, and anti-apoptotic activities and could be used as a food additive.
The coefficients of uniformity Christiansen's uniformity coefficient (CU) and distribution uniformity (DU) are an important parameter for designing irrigation systems, and are an accurate measure for water lose. In this study, three machine learning algorithms Random forest (RF), extreme gradient boosting (XGB) and random forest-extreme gradient boosting (XGB-RF) were developed to predict the water distribution uniformity based on operating pressure, heights of sprinkler, discharge, nozzle diameter, wind speed, humidity, highest and lowest temperature for three different impact sprinklers (KA-4, FOX and 2520) for square and triangular system layout based on four scenarios (input combinations). The main findings were; the highest CU value was 86.7% in the square system of 2520 sprinkler under 200 kPa, 0.5 m height and 0.855 m³/h (Nozzle 2.5 mm). Meanwhile, in the triangular system, it was 87.3% under the same pressure and discharge and 1 m height. For applied machine learning, the highest values of R² were 0.796, 0.825 and 0.929 in RF, XGB and XGB-RF respectively in the first scenario for CU. Moreover, for the DU, the highest values of R² were 0.701, 0.479 and 0.826 in RF, XGB and XGB-RF respectively in the first scenario. The obtained results revealed that the sprinkler height had the lowest impact on modeling of the water distribution uniformity.
This study uses Monte Carlo simulations to study the emergence of polarization plateaus and hysteresis cycles within fullerene-like systems. To explore the dielectric properties of the system, we also applied the Blume-Capel Ising model, which considered critical, coercive and saturation fields. Temperature, ferrielectric parameter, and crystal field all influenced the system's behavior. Multi-state memory devices, spintronics, and materials characterization can benefit from the discovery of multiple loops and polarization plateaus.
Background Traumatic retroclival hematomas (RCHs) are infrequent occurrences among the pediatric population. The existing body of research pertaining to these hematomas primarily consists of case reports or small case series, which do not provide adequate guidance for managing this condition. Objective This study aims to present a report on four cases of RCHs. Additionally, we aim to conduct a systematic review to consolidate the existing literature on pediatric RCHs. Methods The authors conducted a systematic review in accordance with the PRISMA and CARE guidelines. A multivariate logistic regression model was developed to evaluate the potential impact of various clinical variables on clinical outcomes. The study also documented four of our cases, one of which was a rare occurrence of spontaneous subdural RCH. Results A total of 62 traumatic RCHs have been documented in the literature. We documented three cases of traumatic RCHs and one case of spontaneous RCH. A systematic analysis of 65 traumatic RCHs was performed. Of trauma cases, 64.6% demonstrated craniocervical junction instability with 83.3% ligamentous involvement. Thirty-five patients were males. 50.7% were aged between 5 and 9 years. Cranial nerve palsies occurred in 29 patients (27 had abducent palsy), 26 of which resolved within 6 months of trauma. 23.5% underwent surgery, and 76.5% were conservatively managed. Surgeries targeted hematomas, hydrocephalus, or craniocervical instability. Approaches to hematomas included transclival and far/extreme lateral suboccipital approaches. Clinical outcome was good in 75.4% and intermediate or poor in 24.6%. Logistic regression suggested an association between craniocervical junction injuries and poor or intermediate outcomes (OR 4.88, 95% CI (1.17, 27.19), p = 0.04). Conclusion Pediatric RCHs are mostly traumatic and extradural. Children between 5 and 9 years old are most vulnerable. Craniocervical junction injuries, mainly ligamentous, are common in RCHs and are associated with intermediate or poor outcomes. Cervical MRI could be important in cases of trauma to rule out ligamentous injuries of the craniocervical junction. The small size of RCHs should not exempt the careful assessment of craniocervical junction instability. Cranial nerve palsies are common and usually resolve within 6 months. Conservative treatment is typical unless brainstem compression, hydrocephalus, or craniocervical junction instability exists.
Membrane trafficking is a physiological process encompassing different pathways involved in transporting cellular products across cell membranes to specific cell locations via encapsulated vesicles. This process is required for cells to mature and function properly, allowing them to adapt to their surroundings. The retromer complex is a complex composed of nexin proteins and peptides that play a vital role in the endosomal pathway of membrane trafficking. In humans, any interference in normal membrane trafficking or retromer complex can cause profound changes such as those seen in neurodegenerative disorders such as Alzheimer's and Parkinson's. Several studies have explored the potential causative mechanisms in developing both disease processes; however, the role of retromer trafficking in their pathogenesis is becoming increasingly significant with promising therapeutic applications. This manuscript describes the processes involved in membrane transport and the roles of the retromer in the onset and progression of Alzheimer's and Parkinson's. Moreover, we will also explore how these aberrant mechanisms may serve as possible avenues for treatment development in both diseases and the prospect of its future application.
In this work, an inspection of the entropy generation of ternary nanofluids inside an irregular peristaltic channel resulting from heat transfer and fluid viscosity in addition to the combined effects of electric and magnetic fields is conducted. The flow is supposed to be subject to a combination of external forces such as an electric field, a magnetic field, thermal radiation, and Joule heating due to the Lorentz force. This model is a representation of the heat transfer processes of heat exchangers and some types of solar cells. Variation in channel width is an effective factor that has not been addressed by many researchers before, these assumptions are simulated by a set of nonlinear partial differential equations due to the dual effect of electric and magnetic forces and under the influence of special boundary conditions. This set of equations has been converted to non‐dimensional equations and then solved analytically to study the behavior of velocities, heat transfer, and the rate of entropy generation inside the channel under the influence of important embedded parameters. Some notable results have been reached, such as a clear growth of the entropy generation system by using more than one type of nanoparticle as a result of the improvement that occurs in the thermal and magnetic conductivity of the fluid, in addition to the increase in viscosity. The irreversibility resulting from friction and the electric and magnetic fields clearly rises in the middle and diminishes at the walls compared to the irreversibility resulting from thermal transfer.
Macro Group is the largest player in Egypt’s fast-growing cosmeceutical industry founded in 2002, and Macro has about 149 stock-keeping units (“SKUs”) with a 31.4% market share in 2022. The macro group has three-ampoule products for hair, namely, Atrakta, Verdex, and Solodex with an expected forecast of 134,655 FG in 2023 and it’s expected to reach 261,000 FG in 2027. 188 working days per year in 2023 are required to manufacture the forecasted units and 365 working days to manufacture 2027 forecasted units. Through observing the production line of Atrakta, it has been noticed that the production line could be enhanced to increase the production rate, and hence, meet market demands efficiently. Therefore, this paper aims to study and investigate the Atrakta hair ampoules production line to reach the optimum line productivity and to commit to market needs. Studying the Atrakta hair ampules production line is conducted through interviews, production line observation, data collection, and modeling and simulation of the production line. Two scenarios recommending improvements to the production lines are proposed and simulated. The two scenarios differ mainly in the probability distribution of probabilistic inputs. Simulating the system with the recommended improvements for the two scenarios shows similar results of increased productivity. Simulation results of improved systems show an increase of 300% in daily production from 720 FG per day to 2176 FG per day. According to Atrakta's results, the Macro group decided to implement the same recommended improvements on the similar process of Verdex and Solodex ampoules to reach 2176 FG. The required working days to reach forecasted units in 2023 decreased from 188 to 67 days and also decreased from 365 to 132 days in 2027. ArticleHighlights The primary pack items are decreased, and secondary pack of ampoules SKUs has been changed to avoid bottlenecks. The change of primary and secondary pack plays a significant role in increasing the productivity 3 times for the non-sterile ampoules production unit. The increasing of production capacity decreased the required working days in 2023 till 2027.
Institution pages aggregate content on ResearchGate related to an institution. The members listed on this page have self-identified as being affiliated with this institution. Publications listed on this page were identified by our algorithms as relating to this institution. This page was not created or approved by the institution. If you represent an institution and have questions about these pages or wish to report inaccurate content, you can contact us here.
7,602 members
Ola El-Habit
  • Department of Zoology and Entomology
Hatem El-mezayen
  • Department of Biochemistry
Ahmed M. Abd el haleem
  • Department of Electronics, Communications and Computer Engineering
Sameh Soror
  • Department of Biochemistry
Mohamed_kotb Kotb-El-Sayed
  • Department of Biochemistry & Molecular Biology
Ain Helwan, 11795, Cairo, Cairo, Egypt
+2 01226388519