187 research outputs found

    Reaction of nitrilimines and nitrile oxides with hydrazines, hydrazones and oximes

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    This review article discusses the reaction of nitrilimines and nitrile oxides with hydrazines, hydrazones, and oximes. Three reaction modes were observed. The article mainly covers our work published over the last fifteen years, in which interesting heterocyles such as oxadiazoles, triazoles, and tetrazines were synthesized and fully characterized. View Full-Text Keywords

    The role of three different contrast-enhanced, abbreviated MRI protocols as a screening tool of hepatocellular carcinoma in patients with chronic hepatitis C virus infection

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    Purpose: Our study aims to assess the role and diagnostic performance of 3 different contrast-enhanced, abbreviated magnetic resonance imaging (MRI) protocols as a screening tool of hepatocellular carcinoma (HCC). Material and methods: Our retrospective study included 80 patients who were screened for HCC: 47 patients revealed 138 focal hepatic lesions. MRI examinations were performed including full CE-MRI protocols. The MRI was done on a 1.5 T machine. Then 3 different abbreviated contrast-enhanced MRI protocols were analysed separately. The standard dynamic contrast MRI and abbreviated protocols were evaluated following the LI-RADS 2018 lexicon diagnostic features. Results: A considerable overall kappa (k) agreement between the abbreviated 1, 2, and 3 protocols on LI-RADS classification was noted with k = 0.865. There was almost perfect agreement between all abbreviated protocols and full standard protocol on LI-RADS classification, with k = 0.890. As regards the k agreement on LI-RADS classification, there was a considerable highest agreement between the abbreviated 1 protocol and the full standard protocol, with k = 0.980. The abbreviated 1 and 2 protocols showed high diagnostic performance on LI-RADS classification of lesions, with 100% sensitivity, specificity, PPV, NPV, and accuracy, while the abbreviated 3 protocol showed a lesser but comparable sensitivity 96.9%, NPV 99.4, and accuracy 99.4%. Conclusions: Abbreviated contrast-enhanced MRI protocols can be used as a screening tool for the detection of HCC, with high sensitivity, specificity, PPV, NPV, and accuracy close to the full protocol. There was a considerable highest agreement between the abbreviated 1 protocol and the full standard protocol. Subsequently, this protocol can be used as a standard protocol for screening high-risk patients

    Developing Intensity-Duration-Frequency (IDF) Curves From Satellite-Based Precipitation: Methodology and Evaluation

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    Given the continuous advancement in the retrieval of precipitation from satellites, it is important to develop methods that incorporate satellite-based precipitation data sets in the design and planning of infrastructure. This is because in many regions around the world, in situ rainfall observations are sparse and have insufficient record length. A handful of studies examined the use of satellite-based precipitation to develop intensity-duration-frequency (IDF) curves; however, they have mostly focused on small spatial domains and relied on combining satellite-based with ground-based precipitation data sets. In this study, we explore this issue by providing a methodological framework with the potential to be applied in ungauged regions. This framework is based on accounting for the characteristics of satellite-based precipitation products, namely, adjustment of bias and transformation of areal to point rainfall. The latter method is based on previous studies on the reverse transformation (point to areal) commonly used to obtain catchment-scale IDF curves. The paper proceeds by applying this framework to develop IDF curves over the contiguous United States (CONUS); the data set used is Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks – Climate Data Record (PERSIANN-CDR). IDFs are then evaluated against National Oceanic and Atmospheric Administration (NOAA) Atlas 14 to provide a quantitative estimate of their accuracy. Results show that median errors are in the range of (17–22%), (6–12%), and (3–8%) for one-day, two-day and three-day IDFs, respectively, and return periods in the range (2–100) years. Furthermore, a considerable percentage of satellite-based IDFs lie within the confidence interval of NOAA Atlas 14

    Sufficiency and Efficiency of Field Training for Radiology Students During Internship Experience in Najran University, Saudi Arabia

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    Purpose: The study was design to evaluate the effectiveness and adequacy of the internship period employing quantitative study descriptive survey approach.   Theoretical framework: Internship is requirement of every student of radiology program of Radiological Sciences patch for the award of bachelor's degree at Najran University, Saudi Arabia. The competency level would demonstrate influence the sufficiency and efficiency of clinical training during internship period which represent six months after completing nine levels of radiology program.   Design\Methodology\Approach: The survey was distributed to the tow levels of the last year of radiological sciences which composed of 81 male and female students which gathered seventy-seven (77) participants. Data collected through a questionnaire and summarized as percentages, frequencies, means and standard deviations using SPSS version 20.0.   Findings: The study revealed un adequacy of the internship period and showed low efficiency due to its short duration.   Research, Practical, Social Implication:The research construct and variables are identified the effectiveness and adequacy of the internship period.this  study will be the modele of internship with a new qualitative change related to a period of time acceptable to students, similar to other universities.   Originality/Value: The originality and value in this study are the framework conceptance and questionnaire that prepared and proved for evaluating the effectiveness and adequacy of the internship period for student of radiology program.   Conclusion: In general internship period must be efficient and adequate to enhance sufficiency and efficiency experience by intern trainees

    Support through patient internet-communities: Lived experience of Russian in vitro fertilization patients

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    The article is concerned with the life experiences of infertile women going through infertility treatment and their need for social and psychological support, which they try to find in their immediate social environment. The Internet has become one place where everyone can find “people like oneself.” The best support is received from these people who are in the same life situation and are able and willing to share their lived experiences with each other. Communication via the Internet and the formation of a virtual community of patients has both positive and negative aspects, all of which are examined in the article. On the one hand, it creates a psychologically favorable atmosphere and might potentially increase the success rate of IVF treatment. On the other, this leads to the seclusion of patients within the circle of “similar people” and sometimes to negative attitudes towards people outside the circle. The article is based on the author's “netnography” research of a virtual community of Russian In-Vitro Fertilization (IVF)1 patients

    Synthesis, docking and evaluation of novel fused pyrimidine compounds as possible lead compounds with antibacterial and antitumor activities

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    Reaction of a series of hydrazonoyl chlorides with substituted aminopyrimidines afforded good selectivity in most cases leading either to formation of new imidazo[1,2-a]pyrimidine derivatives, or regioisomeric hydrazonamide adducts. The compounds were evaluated for antibacterial and anticancer activities. Screening against 'E. Coli', 'P. aeruginosa', 'S. aureus', 'S. epidermidis', 'B. subtilis' and 'K. rhizophila' did identify several different compound types with MIC of 0.1-0.4 mg/mL. Anticancer evaluation against a HeLa cell line identified one imidazo[1,2-a]pyrimidine lead. An 'in silico' target fishing analysis suggest three possible high value protein targets, Tankyrase-2 (Tank-2), Cyclin-dependent kinase (CDK2) and Epidermal growth factor tyrosine kinase receptor (EGFR), with modelling fit against co-crystallized known ligands. This provides a new structural family lead for further investigation of molecular targets and potential SAR activity development

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

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    Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

    B7-H4 Treatment of T Cells Inhibits ERK, JNK, p38, and AKT Activation

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    B7-H4 is a newly identified B7 homolog that plays an important role in maintaining T-cell homeostasis by inhibiting T-cell proliferation and lymphokine-secretion. In this study, we investigated the signal transduction pathways inhibited by B7-H4 engagement in mouse T cells. We found that treatment of CD3+ T cells with a B7-H4.Ig fusion protein inhibits anti-CD3 elicited T-cell receptor (TCR)/CD28 signaling events, including phosphorylation of the MAP kinases, ERK, p38, and JNK. B7-H4.Ig treatment also inhibited the phosphorylation of AKT kinase and impaired its kinase activity as assessed by the phosphorylation of its endogenous substrate GSK-3. Expression of IL-2 is also reduced by B7-H4. In contrast, the phosphorylation state of the TCR proximal tyrosine kinases ZAP70 and lymphocyte-specific protein tyrosine kinase (LCK) are not affected by B7-H4 ligation. These results indicate that B7-H4 inhibits T-cell proliferation and IL-2 production through interfering with activation of ERK, JNK, and AKT, but not of ZAP70 or LCK
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