30 research outputs found

    Comparative analysis of the efficacy of astigmatic correction after wavefront-guided and wavefront-optimized LASIK in low and moderate myopic eyes

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    AIM: To evaluate and compare the efficacy of the astigmatic correction achieved with laser in situ keratomileusis (LASIK) in eyes with myopic astigmatism using wavefront-guided (WFG) and wavefront-optimized (WFO) ablation profiles. METHODS: Prospective study included 221 eyes undergoing LASIK: 99 and 122 eyes with low and moderate myopic astigmatism (low and moderate myopia groups). Two subgroups were differentiated in each group according to the ablation profile: WFG subgroup, 109 eyes (45/64, low/moderate myopia groups) treated using the Advanced CustomVue platform (Abbott Medical Optics Inc.), and WFO subgroup, 112 eyes (54/58, low/moderate myopia groups) treated using the EX-500 platform (Alcon). Clinical outcomes were evaluated during a 6-month follow-up, including a vector analysis of astigmatic changes. RESULTS: Significantly better postoperative uncorrected visual acuity and efficacy index was found in the WFG subgroups of each group (P≤0.041). Postoperative spherical equivalent and cylinder were significantly higher in WFO subgroups (P≤0.003). In moderate myopia group, a higher percentage of eyes with a postoperative cylinder ≤0.25 D was found in the WFG subgroup (90.6% vs 65.5%, P=0.002). In low and moderate myopia groups, the difference vector was significantly higher in the WFO subgroup compared to WFG (P<0.001). In moderate myopia group, the magnitude (P=0.008) and angle of error (P<0.001) were also significantly higher in the WFO subgroup. Significantly less induction of high order aberrations were found with WFG treatments in both low and moderate myopia groups (P≤0.006). CONCLUSION: A more efficacious correction of myopic astigmatism providing a better visual outcome is achieved with WFG LASIK compared to WFO LASIK.Partially supported by a grant from Abbott Medical Optics

    Bond Strength of Concrete Containing Different Recycled Coarse Aggregates

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    Some of the remnants of construction demolition wastes could be used after recycling as coarse aggregate in concrete industry. Among these wastes are ceramics, shale bricks and hardened concrete. This research was carried out to determine the effect of using such recycled aggregate (RA) as total or partial replacement of the natural dolomite coarse aggregate in concrete mixes on their compressive and bond strength with steel bars. Two types of concrete were investigated in this research which included normal concrete and self-compacted concrete. The main variables taken into consideration wee, the type of concrete, the type and percentage of the recycled aggregate and the age of testing. The consistency of the normal fresh concrete was measured by the slump test. However, the workability and flowability of the self-compacted fresh concrete were measured using slump test, V-funnel test. Out of the experimental test results, equations were predicted which correlated between the concrete compressive strength and bond strength of both the recycled aggregate ordinary concrete and the recycled aggregate self-compacted concrete. These equations were completely different than that of the steel-concrete bond equation of concrete with natural aggregate. Out of this research results, the recycled aggregate concrete could be used in both non structural applications and in some structural applications with special precautions

    Minimally Invasive Approach in Surgical Management of Renal Neoplasms National Cancer Institute Experience

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    BACKGROUND: Minimally invasive nephrectomy is considered a technically challenging procedure requiring a long learning curve to reach acceptable warm ischemia time and perioperative complications. These minimally invasive techniques result in a shorter hospital stay and less post-operative pain. AIM: This study aims to demonstrate the National Cancer Institute experience regarding the benefits of laparoscopic and robot-assisted nephrectomy over open technique. METHODS: This is a retrospective descriptive cohort study including 62 patients with renal masses treated with nephrectomy whether partial, total or radical, 26 cases were treated by minimally invasive techniques (8 robotic and 18 laparoscopic), while 36 cases were treated by open technique. Inclusion criteria were patients between 20 and 70 years with renal neoplasm without renal vein thrombosis, with tumor stage T1 or T2 N0 M0. Exclusion criteria were patients with medical comorbidities that preclude surgical management or minimally invasive techniques and patients refusing surgery in general. RESULTS: Minimally invasive nephrectomy resulted in shorter hospital stay (mean hospital stay was 2.2 days for the minimally invasive group and 3.6 days for the open group) and less post-operative pain than open technique (p &lt; 0.001 and = 0.002, respectively), while open technique resulted in shorter operation time (p = 0.039, mean operation time 147.8 min compared to 184.8 in the minimally invasive group). CONCLUSION: Minimally invasive nephrectomy (laparoscopic and robotic) resulted in less post-operative pain and shorter hospital stay compared to open technique despite consuming longer operation time which may be decreased by improving the learning curve of operating surgeons

    Humoral and cellular immune responses to modified hepatitis B plasmid DNA vaccine in mice

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    Purpose: To evaluate the immunogenicity and types of immune response of a quality-controlled modified recombinant hepatitis B surface antigen (HBsAg) plasmid encoding HBsAg in mice.Methods: The characterized plasmid DNA was used in the immunization of Balb/c mice. Three groups of mice were intramuscularly injected with three different concentrations (50, 25 and 10 μg/100 μL) of the modified plasmid. Humoral immune response was monitored by enzyme-linked immunosorbent assay (ELISA), while cellular immune response was investigated by analysis of spleen cytokine profile (TNFα, IFN γ and IL2) as well as CD69 expression level in CD4 and CD8 positive cells.Results: In general, the activated CD4 cells showing intracellular cytokines were higher than CD8 positive population of cells (p &lt; 0.05). These findings indicate that the vaccine induced both a humoral and cellular immunity. Cytokine profile also showed high levels of TNFα, IFN γ and IL2 and CD69 expression in the group of animals immunized at a dose of 10 μg when compared to control group (p &lt; 0.05).Conclusion: A 10 μg dose intramuscular injection of the modified DNA-based vaccine encoding HBsAg in mice induces both high humoral and cellular immune responses.Keywords: Hepatitis B virus, Plasmid DNA, Vaccine, Spleen cytokines, Humoral and cellular immune response

    Male Oxidative Stress Infertility (MOSI): Proposed Terminology and Clinical Practice Guidelines for Management of Idiopathic Male Infertility

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    Despite advances in the field of male reproductive health, idiopathic male infertility, in which a man has altered semen characteristics without an identifiable cause and there is no female factor infertility, remains a challenging condition to diagnose and manage. Increasing evidence suggests that oxidative stress (OS) plays an independent role in the etiology of male infertility, with 30% to 80% of infertile men having elevated seminal reactive oxygen species levels. OS can negatively affect fertility via a number of pathways, including interference with capacitation and possible damage to sperm membrane and DNA, which may impair the sperm’s potential to fertilize an egg and develop into a healthy embryo. Adequate evaluation of male reproductive potential should therefore include an assessment of sperm OS. We propose the term Male Oxidative Stress Infertility, or MOSI, as a novel descriptor for infertile men with abnormal semen characteristics and OS, including many patients who were previously classified as having idiopathic male infertility. Oxidation-reduction potential (ORP) can be a useful clinical biomarker for the classification of MOSI, as it takes into account the levels of both oxidants and reductants (antioxidants). Current treatment protocols for OS, including the use of antioxidants, are not evidence-based and have the potential for complications and increased healthcare-related expenditures. Utilizing an easy, reproducible, and cost-effective test to measure ORP may provide a more targeted, reliable approach for administering antioxidant therapy while minimizing the risk of antioxidant overdose. With the increasing awareness and understanding of MOSI as a distinct male infertility diagnosis, future research endeavors can facilitate the development of evidence-based treatments that target its underlying cause

    Cohort Profile: Burden of Obstructive Lung Disease (BOLD) study

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    The Burden of Obstructive Lung Disease (BOLD) study was established to assess the prevalence of chronic airflow obstruction, a key characteristic of chronic obstructive pulmonary disease, and its risk factors in adults (≥40 years) from general populations across the world. The baseline study was conducted between 2003 and 2016, in 41 sites across Africa, Asia, Europe, North America, the Caribbean and Oceania, and collected high-quality pre- and post-bronchodilator spirometry from 28 828 participants. The follow-up study was conducted between 2019 and 2021, in 18 sites across Africa, Asia, Europe and the Caribbean. At baseline, there were in these sites 12 502 participants with high-quality spirometry. A total of 6452 were followed up, with 5936 completing the study core questionnaire. Of these, 4044 also provided high-quality pre- and post-bronchodilator spirometry. On both occasions, the core questionnaire covered information on respiratory symptoms, doctor diagnoses, health care use, medication use and ealth status, as well as potential risk factors. Information on occupation, environmental exposures and diet was also collected

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    A comparative study of lifetime reliability of planar MOSFET and FinFET due to BTI for the 16 nm CMOS technology node based on reaction-diffusion model

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    Intensive scaling of Integrated Circuits is a crucial factor for achieving high performance and astronomical packing density. However, this scaling is pushing planar MOSFET to its physical limitations. Nowadays, FinFET emerges as a promising alternative technology for planar MOSFET, due to their better efficiency. Nevertheless, this inevitably leads to a rising concern on the reliability of FinFET as the circuit lifetime reliability cannot be neglected due to this accelerated scaling of Integrated Circuits. This paper is considered as the first work that: 1) detects which CMOS technology, planar MOSFET or FinFET, is more robust against Bias Temperature Instability (BTI) aging degradation for the advanced nodes such as 16 nm; 2) precisely computes the effect of BTI on 16 nm FinFET using an adequate BTI Reaction Diffusion model that takes into consideration the effects of finite oxide thickness, and the influence of polysilicon; 3) investigates the efficiency in terms of power consumption and area for the predominant circuit level techniques that could be implemented to overcome the negative impact of BTI for FinFET technology. This research clearly indicates that FinFET technology is more robust against BTI aging degradation than planar MOSFET as the delay percentage for FinFET technology is lower than planar MOSFET technology by 26%. © 2019 Elsevier Lt

    Evaluation of crestal sinus floor elevation in cases exhibiting an oblique sinus floor with a residual bone height of 4.0–7.0 mm using Densah burs with simultaneous implant placement: a prospective clinical study

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    Abstract Purpose To evaluate the effectiveness of using Densah burs for lifting the maxillary sinus membrane in cases with an oblique sinus floor with a residual bone height of 4–7 mm. Methods The study was conducted on 16 patients, comprising 9 males and 7 females, aged 25–60 years, split into two groups of 8 each: group I with a residual bone height of 4–5.5 mm below the sinus floor and group II with a residual bone height of 5.5–7 mm. Exclusion criteria included smokers, presence of systemic or metabolic conditions that contraindicate implant placement and a local sinus pathology. The study involved the use of Densah burs, using the osseodensification concept to elevate the sinus floor, along with simultaneous dental implant placement. The integrity of the sinus membrane was verified via clinical examination and a confirmatory cone beam computed tomography scan. Results The study revealed that out of the 16 cases, one case had a sinus membrane perforation, confirmed clinically at the time of the operation. The study achieved a mean lift of 4.42 mm and a mean final seating torque of 35.5 N/cm. At the 1-year follow-up, all cases showed clinical success, with no signs of sinus pathology or complications. Conclusions In cases with oblique sinus floors and a residual bone height of 4–7 mm in moderately atrophic posterior maxilla, the osseodensification concept proved to be a safe and effective method for performing sinus lift procedures with simultaneous implantation. Graphical Abstrac

    Design Framework to Overcome Aging Degradation of the 16 nm VLSI Technology Circuits

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