96 research outputs found

    Modeling and simulation of architectured iron-based SMA materials

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    ASME Conference on Smart Materials, Adaptive Structures and Intelligent Systems (SMASIS 2017), Snowbird, UT, SEP 18-20, 2017International audienceThe paper presents results of finite element analysis of architectured iron-based shape memory alloy (SMA) samples consisting of bulk SMA and void combined to different proportions and according to different geometric patterns. The finite element simulation uses a constitutive model for iron-based SMAs that was recently developed by the authors in order to account for the behavior of the bulk material. The simulation of the architectured SMA is then carried out using a unit cell method to simplify calculations and reduce computation time. For each unit cell, periodic boundary conditions are assumed and enforced. The validity of this assumption is demonstrated by comparing the average behavior of one unit cell to that of a considerably larger sample comprising multiple such cells. The averaging procedure used is implemented numerically, by calculating volume averages of mechanical fields such as stress and strain over each finite element model considered as a combination of mesh elements

    Aorto-Uni-Iliac Stent Grafts with and without Crossover Femorofemoral Bypass for Treatment of Abdominal Aortic Aneurysms: A Parallel Observational Comparative Study

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    We investigated the safety and efficacy of primary aorto-uni-iliac (AUI) endovascular aortic repair (EVAR) without fem-fem crossover in patients with abdominal aortic aneurysm (AAA) and concomitant aortoiliac occlusive disease. 537 EVARs were implemented between 2002 and 2015 in University Hospital Galway, a tertiary referral center for aortic surgery and EVAR. We executed a parallel observational comparative study between 34 patients with AUI with femorofemoral crossover (group A) and six patients treated with AUI but without the crossover (group B). Group B patients presented with infrarenal AAAs with associated total occlusion of one iliac axis and high comorbidities. Technical success was 97% (n=33) in group A and 85% (n=5) in group B (P=0.31). Primary and assisted clinical success at 24 months were 88% (n=30) and 12% (n=4), respectively, in group A, and 85% (n=5) and 15% (n=1), respectively, in group B (P=0.125). Reintervention rate was 10% (n=3) in group A and 0% in group B (P=0.084). No incidence of postoperative critical lower limb ischemia or amputations occurred in the follow-up period. AUI without crossover bypass is a viable option in selected cases

    Optic nerve head perfusion changes in eyes with proliferative diabetic retinopathy treated with intravitreal ranibizumab or photocoagulation: a randomized controlled trial

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    Background: Proliferative diabetic retinopathy (PDR) is a serious sight-threatening disease, and half of the patients with high-risk PDR can develop legal blindness within 5 years, if left untreated. This study was aimed at comparing panretinal photocoagulation (PRP) and intravitreal ranibizumab injections in terms of radial peripapillary capillary (RPC) density on optical coherence tomography angiography (OCTA) in patients with treatment-naive PDR.  Methods: This open-label, prospective, randomized clinical trial included 50 patients with treatment-naive PDR with optic disc neovascularization and randomized them into two groups: group 1, with patients undergoing two sessions of PRP 2 weeks apart, and group 2, with patients received three intravitreal ranibizumab injections (0.5 mg) 1 month apart for 3 consecutive months. Patients underwent a full ophthalmological examination, including best-corrected distance visual acuity (BCDVA) measurement in the logarithm of minimal angle of resolution (logMAR) notation and OCTA before intervention and monthly after the last laser session or the first intravitreal ranibizumab injection for 3 months of follow-up. Visual field (VF) was tested at the beginning and end of 3 months.   Results: Forty-two (84%) eyes completed the 3-month follow-up, including 22 eyes in the PRP group (88%) and 20 (80%) eyes in the ranibizumab group. The two groups were comparable in terms of demographic characteristics, diabetes duration, baseline BCDVA, glycated hemoglobin level, OCTA parameters, VF indices, and intraocular pressure (all P > 0.05). The RPC density change from baseline to the 3-month follow-up was significantly lower in the PRP group than in the ranibizumab group (mean difference in RPC density change: - 3.61%; 95% confidence interval: - 5.57% to - 1.60%; P = 0.001). The median (interquartile range) logMAR change from baseline to the 3-month follow-up (0.0 [0.2]) was significantly higher in the PRP group than in the ranibizumab group (- 0.15 [0.3]; P < 0.05). The median changes in central foveal thickness from baseline to the 3-month follow-up differed significantly between the two groups (P = 0.001). Conclusions: In eyes with PDR and neovascularization of the disc RPC density on OCTA increased in the ranibizumab group and decreased in the PRP group. Visual acuity gain was higher in the ranibizumab group than in the PRP group. Future multicenter trials addressing our limitations are required to verify the findings of this study

    Recent Progress in Lipid Nanoparticles for Cancer Theranostics: Opportunity and Challenges

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    Cancer is one of the major leading causes of mortality in the world. The implication of nanotherapeutics in cancer has garnered splendid attention owing to their capability to efficiently address various difficulties associated with conventional drug delivery systems such as non-specific biodistribution, poor efficacy, and the possibility of occurrence of multi-drug resistance. Amongst a plethora of nanocarriers for drugs, this review emphasized lipidic nanocarrier systems for delivering anticancer therapeutics because of their biocompatibility, safety, high drug loading and capability to simultaneously carrying imaging agent and ligands as well. Furthermore, to date, the lack of interaction between diagnosis and treatment has hampered the efforts of the nanotherapeutic approach alone to deal with cancer effectively. Therefore, a novel paradigm with concomitant imaging (with contrasting agents), targeting (with biomarkers), and anticancer agent being delivered in one lipidic nanocarrier system (as cancer theranostics) seems to be very promising in overcoming various hurdles in effective cancer treatment. The major obstacles that are supposed to be addressed by employing lipidic theranostic nanomedicine include nanomedicine reach to tumor cells, drug internalization in cancer cells for therapeutic intervention, off-site drug distribution, and uptake via the host immune system. A comprehensive account of recent research updates in the field of lipidic nanocarrier loaded with therapeutic and diagnostic agents is covered in the present article. Nevertheless, there are notable hurdles in the clinical translation of the lipidic theranostic nanomedicines, which are also highlighted in the present review along with plausible countermeasures.Peer reviewedFinal Published versio

    Revival of Endovascular Visual Assessment of Anastomotic Patency in Coronary Artery Bypass Graft Surgery

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    Background : Coronary artery bypass graft surgery (CABG) is considered the most performed cardiac surgery nowadays. The outcome of CABG surgery has been linked to several aspects. Above all is graft patency which is a crucial element contributing to success of the surgery. Early graft failure following CABG has been recorded in up to 12% of grafts (left IMA 7%; saphenous vein graft 8%). Objectives: The aim of the present study was to determine the efficacy and feasibility of the endovascular visualization to detect anastomotic errors. Patients and methods: The study included 40 patients who presented with CAD and were candidates for coronary artery bypass grafting (CABG). All anastomoses were assessed using 1.9 mm telescope and endovascular visualisation score was recorded followed by routine assessment of grafts quality using transient time flow meter. Results: In this prospective cross-sectional study, we included a total of forty patients who underwent CABG which enabled intraoperative assessment of the quality of 70 venous grafts. There is a statistically significant correlation between the endovascular visual score and the mean flow across the OM and RCA grafts. For the Diagonal grafts , the correlation was less evident due to the small sample number. Conclusion: Coronary angioscopy is a simple and safe procedure and provides clinically relevant information. It provides immediate control of anastomotic quality and it can assist in the assessment of the native coronary artery. Together with transient time flowmeter, it provides a new alternative for the quality control of CABG surgery

    Yellow fever outbreak in Kenya:A review

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    Yellow fever (YF) is a viral acute hemorrhagic illness caused by infected mosquitoes of the flavivirus family. The first yellow fever outbreak in Kenya was in 1992. Similar outbreaks were recorded in the western part of the country in 1993, 1995, and 2011, particularly in the Rift Valley province of Kenya. In early 2022, the viral acute illness resurfaced and hit Kenya. On January 12, 2022, the first case was discovered, with over 14 patients suffering from fever, jaundice, and joint and muscle pains. On March 4, 2022, a yellow fever outbreak re-emerged in Kenya, affecting 11 wards in Isiolo County. The fatality rate recorded was 11.3% (six deaths), with Chari accounting for 39.6% of the total 21 cases, Cherab 14 (26.4%), and 5 Garba Tulla (9.4%). This has the potential to further endanger the nation's economic growth while also negatively impacting people's daily lives in a part of the world that is already dealing with the catastrophic impacts of the coronavirus pandemic. However, there is no curative therapy for yellow fever. The only options for curbing its spread are through vaccination and preventive measures. Hence, Kenya's government must take responsibility for requiring vaccination of its citizens, implement an active national disease surveillance protocol, and set up anti-yellow fever campaigns in the country

    Cytotoxicity–Associated gene (CagA) Producing Helicobacter pylori Increased Risk of Developing Colorectal Carcinoma in Iraqi Patients.

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    Infection with Helicobacter pylori, particularly with strains positive for cytotoxicity– associated gene (CagA) gene, increases the risk of gastric adenocarcinoma and it may be associated with carcinogenesis in extra gastric target organ. The aim of this study to explore the possible association between CagA positive H. pylori and colorectal carcinoma and determine the association with clinico-pathological features. Paraffin embedded tumor specimens from (49) patients with colorectal adenocarcinoma and (30) healthy control were assessed by in situ hybridization for the expression of H. pylori CagA mRNA. Statistical analysis of H. pylori CagA positive expression revealed highly significant difference in colorectal carcinoma patients than in control group. There was no relationship between H. pylori CagA positive expression and range of clinicopathological features. Among patients infected with H. pylori CagA positive is associated with increased risk for colonic cancer

    Application of a gene modular approach for clinical phenotype genotype association and sepsis prediction using machine learning in meningococcal sepsis

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    Sepsis is a major global health concern causing high morbidity and mortality rates. Our study utilized a Meningococcal Septic Shock (MSS) temporal dataset to investigate the correlation between gene expression (GE) changes and clinical features. The research used Weighted Gene Co-expression Network Analysis (WGCNA) to establish links between gene expression and clinical parameters in infants admitted to the Pediatric Critical Care Unit with MSS. Additionally, various machine learning (ML) algorithms, including Support Vector Machine (SVM), Naive Bayes, K-Nearest Neighbors (KNN), Decision Tree, Random Forest, and Artificial Neural Network (ANN) were implemented to predict sepsis survival. The findings revealed a transition in gene function pathways from nuclear to cytoplasmic to extracellular, corresponding with Pediatric Logistic Organ Dysfunction score (PELOD) readings at 0, 24, and 48 h. ANN was the most accurate of the six ML models applied for survival prediction. This study successfully correlated PELOD with transcriptomic data, mapping enriched GE modules in acute sepsis. By integrating network analysis methods to identify key gene modules and using machine learning for sepsis prognosis, this study offers valuable insights for precision-based treatment strategies in future research. The observed temporal-spatial pattern of cellular recovery in sepsis could prove useful in guiding clinical management and therapeutic interventions

    Advancing the Understanding of Clinical Sepsis Using Gene Expression-Driven Machine Learning to Improve Patient Outcomes

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    Sepsis remains a major challenge that necessitates improved approaches to enhance patient outcomes. This study explored the potential of Machine Learning (ML) techniques to bridge the gap between clinical data and gene expression information to better predict and understand sepsis. We discuss the application of ML algorithms, including neural networks, deep learning, and ensemble methods, to address key evidence gaps and overcome the challenges in sepsis research. The lack of a clear definition of sepsis is highlighted as a major hurdle, but ML models offer a workaround by focusing on endpoint prediction. We emphasize the significance of gene transcript information and its use in ML models to provide insights into sepsis pathophysiology and biomarker identification. Temporal analysis and integration of gene expression data further enhance the accuracy and predictive capabilities of ML models for sepsis. Although challenges such as interpretability and bias exist, ML research offers exciting prospects for addressing critical clinical problems, improving sepsis management, and advancing precision medicine approaches. Collaborative efforts between clinicians and data scientists are essential for the successful implementation and translation of ML models into clinical practice. ML has the potential to revolutionize our understanding of sepsis and significantly improve patient outcomes. Further research and collaboration between clinicians and data scientists are needed to fully understand the potential of ML in sepsis management

    Soluble egg antigen of Schistosoma Haematobium induces HCV replication in PBMC from patients with chronic HCV infection

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    BACKGROUND: This study was conducted to examine, in vitro , the effect of soluble egg antigen (SEA) of S. haematobium on intracellular HCV RNA load in peripheral mononuclear cells (PBMC) as well as on cell proliferation in patients with chronic HCV infection. METHODS: PBMC from 26 patients with chronic HCV infection were cultured for 72 hours in presence and absence of 50 μg SEA/ml medium. Intracellular HCV RNA quantification of plus and minus strands was assessed before and after stimulation. PBMC from five healthy subjects were cultured for 7 days, flow cytometric analysis of DNA content was used to assess the mitogenic effect of SEA on PBMC proliferation compared to phytoheamaglutinine (PHA). RESULTS: Quantification of the intracellular viral load showed increased copy number/cell of both or either viral strands after induction with SEA in 18 of 26 patients (69.2%) thus indicating stimulation of viral replication. Flow cytometric analysis showed that mean ± S.D. of percent values of cell proliferation was induced from 3.2 ± 1.5% in un-stimulated cells to 16.7 ± 2.5 % and 16.84 ± 1.7 % in cells stimulated with PHA and SEA respectively. CONCLUSION: the present study supports earlier reports on SEA proliferative activity on PBMC and provides a strong evidence that the higher morbidity observed in patients co-infected with schistosomiasis and HCV is related, at least in part, to direct stimulation of viral replication by SEA
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