403 research outputs found

    Report of Bufo tihamicus karyotype from Saudi Arabia

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    This study gives a description of the Karyotype of the Tihama toad Bufo tihamicus from Saudi Arabia. Samples of males and females of Bufo tihamicus Parker were collected from Gazan Province of Kingdom of Saudi Arabia. The karyotype consists of a diploid number 2n = 22 and the fundamental number NF = 44 in both of the sexes. No heteromorphism in relation to sex chromosome pair was found.Keywords: Amphibian, karyotype, chromosome, Bufo tihamicusAfrican Journal of Biotechnology Vol. 12(16), pp. 2120-212

    Anti-diabetic properties of Securinega virosa (Euphorbiaceae) leaf extract

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    This study was undertaken to evaluate the hypoglycemic effect of methanol extract of securinega virosa leaves on blood levels of streptozocin-induced diabetes rats. Three doses of the extract (100, 300 and 600 mg/kg) were administered intraperitoneally. After 2 h of extract administration there was no significant change in the blood glucose levels in all the three doses of the extract. Also after 4, 8 and 24 h of extract administration there was a significant (p < 0.05 - 0.001) decrease in the blood glucose levelsin all the three doses of the extract. The preliminary phytochemical screening revealed the presence of reducing sugars, cardiac glycosides, resin, tannins, saponins, glycosides, flavonoids, glycerin carbohydrate, anthraquine and steroids. The median lethal dose (LD50) in rats was calculated to be 1264.9 mg/kg body weight

    The march of pluripotent stem cells in cardiovascular regenerative medicine

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    Cardiovascular disease (CVD) continues to be the leading cause of global morbidity and mortality. Heart failure remains a major contributor to this mortality. Despite major therapeutic advances over the past decades, a better understanding of molecular and cellular mechanisms of CVD as well as improved therapeutic strategies for the management or treatment of heart failure are increasingly needed. Loss of myocardium is a major driver of heart failure. An attractive approach that appears to provide promising results in reducing cardiac degeneration is stem cell therapy (SCT). In this review, we describe different types of stem cells, including embryonic and adult stem cells, and we provide a detailed discussion of the properties of induced pluripotent stem cells (iPSCs). We also present and critically discuss the key methods used for converting somatic cells to pluripotent cells and iPSCs to cardiomyocytes (CMs), along with their advantages and limitations. Integrating and non-integrating reprogramming methods as well as characterization of iPSCs and iPSC-derived CMs are discussed. Furthermore, we critically present various methods of differentiating iPSCs to CMs. The value of iPSC-CMs in regenerative medicine as well as myocardial disease modeling and cardiac regeneration are emphasized

    Microbiome diversity in African American, European American, and Egyptian colorectal cancer patients

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    Purpose: Although there is an established role for microbiome dysbiosis in the pathobiology of colorectal cancer (CRC), CRC patients of various race/ethnicities demonstrate distinct clinical behaviors. Thus, we investigated microbiome dysbiosis in Egyptian, African American (AA), and European American (EA) CRC patients. Patients and methods: CRCs and their corresponding normal tissues from Egyptian (n = 17) patients of the Alexandria University Hospital, Egypt, and tissues from AA (n = 18) and EA (n = 19) patients at the University of Alabama at Birmingham were collected. DNA was isolated from frozen tissues, and the microbiome composition was analyzed by 16S rRNA sequencing. Differential microbial abundance, diversity, and metabolic pathways were identified using linear discriminant analysis (LDA) effect size analyses. Additionally, we compared these profiles with our previously published microbiome data derived from Kenyan CRC patients. Results:Differential microbiome analysis of CRCs across all racial/ethnic groups showed dysbiosis. There were high abundances of Herbaspirillum and Staphylococcus in CRCs of Egyptians, Leptotrichia in CRCs of AAs, Flexspiria and Streptococcus in CRCs of EAs, and Akkermansia muciniphila and Prevotella nigrescens in CRCs of Kenyans (LDA score \u3e4, adj. p-value Conclusions: Our findings showed altered mucosa-associated microbiome profiles of CRCs and their metabolic pathways across racial/ethnic groups. These findings provide a basis for future studies to link racial/ethnic microbiome differences with distinct clinical behaviors in CRC

    Generalized nonreciprocity in an optomechanical circuit via synthetic magnetism and reservoir engineering

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    Synthetic magnetism has been used to control charge neutral excitations for applications ranging from classical beam steering to quantum simulation. In optomechanics, radiation-pressure-induced parametric coupling between optical (photon) and mechanical (phonon) excitations may be used to break time-reversal symmetry, providing the prerequisite for synthetic magnetism. Here we design and fabricate a silicon optomechanical circuit with both optical and mechanical connectivity between two optomechanical cavities. Driving the two cavities with phase-correlated laser light results in a synthetic magnetic flux, which in combination with dissipative coupling to the mechanical bath, leads to nonreciprocal transport of photons with 35dB of isolation. Additionally, optical pumping with blue-detuned light manifests as a particle non-conserving interaction between photons and phonons, resulting in directional optical amplification of 12dB in the isolator through direction. These results indicate the feasibility of utilizing optomechanical circuits to create a more general class of nonreciprocal optical devices, and further, to enable novel topological phases for both light and sound on a microchip.Comment: 18 pages, 8 figures, 4 appendice

    Medical students' perceptions of complementary and alternative medicine therapies: A pre- and post-exposure survey in Majmaah University, Saudi Arabia

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    Background: Evidently, Complementary and Alternative Medicine (CAM) is increasingly a recognized medical practice that efficiently uses multiple treatment therapies and techniques in promoting the health  and wellbeing of people as well as preventing and managing a variety of human disorders. Research in CAM, which courses exposure to diverse healthcare professionals, is important from many perspectives including improvement in teaching skills of faculty, enhancing capacity building, and  innovative curriculum development. This pre- and post-design crosssectional study aimed to assess perceptions, training needs, personal usage, use in office practice, and knowledge of two batches of medical students toward CAM therapies in Majmaah University, Saudi Arabia.Materials and Methods: The second year medical students of the first (year 2012-13) and second (year 2013-2014) batch [n=26 &amp; 39, respectively] were selected for this study. A reliable 16-item  self-administered questionnaire was distributed among all students for answering before and after the 48-hour specific 19 CAM therapies course, in terms of CAM therapies are clearly conventional or  alternative, training needs, effectiveness, personal use, use in practice, management of two clinical cases by CAM or conventional therapies, and views about which evidence based approach strongly support individual CAM modalities.Results: Medical students' knowledge and perceptions of CAM therapies significantly improved across some sub-items of CAM questionnaire with a positive trend in the rest of its items including their views about CAM therapies, need for further training, personal use of therapies and advising patients regarding CAM practices strongly supported by randomized clinical controlled trials and published case studies.Conclusion: CAM course tends to have positive impact on the knowledge and perceptions of medical students, in addition to need for further training, and personal use and use of CAM therapies in practice in line with strong evidence-based data regarding therapeutic efficacy. The preliminary results of this study call for further research in specific CAM modalities with a larger sample in academic settings across the nation. Key words: Medical students; Complementary and Alternative Medicine; CAM course; CAM therapies; pre-post design study; Saudi Arabia

    Concurrent system programming with effect handlers

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    © Springer International Publishing AG, part of Springer Nature 2018. Algebraic effects and their handlers have been steadily gaining attention as a programming language feature for composably expressing user-defined computational effects. While several prototype implementations of languages incorporating algebraic effects exist, Multicore OCaml incorporates effect handlers as the primary means of expressing concurrency in the language. In this paper, we make the observation that effect handlers can elegantly express particularly difficult programs that combine system programming and concurrency without compromising performance. Our experimental results on a highly concurrent and scalable web server demonstrate that effect handlers perform on par with highly optimised monadic concurrency libraries, while retaining the simplicity of direct-style code

    MR thermometry characterization of a hyperthermia ultrasound array designed using the k-space computational method

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    BACKGROUND: Ultrasound induced hyperthermia is a useful adjuvant to radiation therapy in the treatment of prostate cancer. A uniform thermal dose (43°C for 30 minutes) is required within the targeted cancerous volume for effective therapy. This requires specific ultrasound phased array design and appropriate thermometry method. Inhomogeneous, acoustical, three-dimensional (3D) prostate models and economical computational methods provide necessary tools to predict the appropriate shape of hyperthermia phased arrays for better focusing. This research utilizes the k-space computational method and a 3D human prostate model to design an intracavitary ultrasound probe for hyperthermia treatment of prostate cancer. Evaluation of the probe includes ex vivo and in vivo controlled hyperthermia experiments using the noninvasive magnetic resonance imaging (MRI) thermometry. METHODS: A 3D acoustical prostate model was created using photographic data from the Visible Human Project(®). The k-space computational method was used on this coarse grid and inhomogeneous tissue model to simulate the steady state pressure wavefield of the designed phased array using the linear acoustic wave equation. To ensure the uniformity and spread of the pressure in the length of the array, and the focusing capability in the width of the array, the equally-sized elements of the 4 × 20 elements phased array were 1 × 14 mm. A probe was constructed according to the design in simulation using lead zerconate titanate (PZT-8) ceramic and a Delrin(® )plastic housing. Noninvasive MRI thermometry and a switching feedback controller were used to accomplish ex vivo and in vivo hyperthermia evaluations of the probe. RESULTS: Both exposimetry and k-space simulation results demonstrated acceptable agreement within 9%. With a desired temperature plateau of 43.0°C, ex vivo and in vivo controlled hyperthermia experiments showed that the MRI temperature at the steady state was 42.9 ± 0.38°C and 43.1 ± 0.80°C, respectively, for 20 minutes of heating. CONCLUSION: Unlike conventional computational methods, the k-space method provides a powerful tool to predict pressure wavefield in large scale, 3D, inhomogeneous and coarse grid tissue models. Noninvasive MRI thermometry supports the efficacy of this probe and the feedback controller in an in vivo hyperthermia treatment of canine prostate

    Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015

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    SummaryBackground The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. Methods We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors—the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI). Findings Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57·8% (95% CI 56·6–58·8) of global deaths and 41·2% (39·8–42·8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211·8 million [192·7 million to 231·1 million] global DALYs), smoking (148·6 million [134·2 million to 163·1 million]), high fasting plasma glucose (143·1 million [125·1 million to 163·5 million]), high BMI (120·1 million [83·8 million to 158·4 million]), childhood undernutrition (113·3 million [103·9 million to 123·4 million]), ambient particulate matter (103·1 million [90·8 million to 115·1 million]), high total cholesterol (88·7 million [74·6 million to 105·7 million]), household air pollution (85·6 million [66·7 million to 106·1 million]), alcohol use (85·0 million [77·2 million to 93·0 million]), and diets high in sodium (83·0 million [49·3 million to 127·5 million]). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa. Interpretation Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden. Funding Bill & Melinda Gates Foundation
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