13 research outputs found

    Nuclear Shape Transition, Triaxiality and Energy Staggering of gamma Band States for Even-Even Xenon Isotopic Chain

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    The positive-parity states of even-even Xe nuclei are investigated within the framework of modified O(6) limit of the interacting boson model (IBM1). The effective three-body interaction [QQQ] where Q is the IBM O(6) quadrupole operator is introduced to exhibit the triaxiality nature. The shape of nuclear surface is described by the deformation parameters beta, gamma by using the intrinsic coherent state. The potential energy surfaces (PES) of the transition U(5)-Triaxiality-O(6) are calculated and analyzed and the critical phase transition points are identified. For each nucleus a fitting procedure is adopted to get the best model parameters by fitting some selected calculated energy levels and B(E2)transition rates ratios with experimental ones. These ratios are analyzed because they serve as effective order parameters in the shape phase transition. The nuclei in Xe isotopic chain evolve from spherical vibrator U(5) to gamma-soft rotor O(6) by increasing the boson number from N=3 (heavy isotope 132Xe) to N=10 (light isotope 120Xe) and the isotope 126Xe represent the critical nucleus. The nucleus 128Xe has triaxial nature. To deal with high spin states in gamma band in 118- 128Xe isotopic chain to investigate and exhibit the odd-even spin energy staggering, we introduce the two parameters collective nuclear softness rotor model (CNS2). Three different staggering indices depending on the dipole transitions linking the two families of spins and the quadrupole transitions within each spin family are considered. Strong odd-even spin energy staggering has been seen. As a link between the IBM and CNS2 models we observed that the energy difference between the gamma-band and ground state band normalized to decreases with increasing the mass numberComment: 20 pages,4 tables, 7 figures and 59 reference

    MORPHOLOGICAL CHARACTERIZATION, POLLEN GRAIN FERTILITY AND SOME CHEMICAL CHARACTERS OF SELECTED MANDARIN (Citrus Spp.) VARIETIES

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    The present research aimed to characterize physical and morphological features of thirteen varieties of mandarin as one of the National Gene Bank and Genetic Resources (NGBGR) objectives in Egypt which include also, collection, conserva-tion, characterization, and evaluation of agricul-tural genetic resources. The present study investi-gates the morphological characterization, pollen grain fertility and sterility as well as fruit chemical characterization (vitamin C, PH, T.S.S and acidi-ty) of 13 mandarin varieties (Citrus sp.).Including Balady, Malawy, Chine mandarin, Clementine, Celiopatra, Centra, Satsuma, Tangerine Dancy, El-Shorbagee, Sonbol, Sayed Marri, Abd El-Razik and Aswan. The Physical and morphological char-acterization descriptors revealed differences among varieties. Characterization of tree shape resulted in eight obloid varieties and five were spheroids. Leaf lamina shape morphological char-acteristic studies showed one elliptic variety, three ovate and 9 lanceolate. Fruit shape studies indicat-ed that five varieties were pyriforum, five obloid and three were spheroid. Fruit apex shape demon-strated that seven varieties were depressed, while six were truncate. Differences in flavedo (skin) color among varieties revealed that seven were orange; two were dark orange and one variety for each of (light orange, green yellow, dark yellow and yellow). As to the color of the pulp (flesh), results indicated that two varieties were yellow, 10 were orange and one was orange-red. The average number of carples per fruit ranged 10-14 carple in 9 varieties and from 5-9 carple in four varieties. The average number of seeds per fruit revealed that five varieties had ten to nineteen seeds; three varieties hold 20-50 seeds and two varieties con-tained five to nine seeds, one variety included one to four seeds, while two varieties had no seeds. Other morphological studies are investigated and will be presented. Fruit chemical characterization disclosed that Malawy had the highest vitamin C concentration (44.82 mg/100 ml) whereas both of Celiopatra and Satsuma showed the lowest con-centration (15.0 and 14.0 mg/100 ml, respective-ly).The greatest pH was determined in Abd El-Razik (pH 3.91) variety in contrast to the more acidity (pH 3.12-3.77) found in El-Shorbagee and Chine mandarin juice, respectively. The best total soluble solids were determined in the Abd El-Razik (15.1%), whereas the least ones were found in Satsuma (9.13%). Chine mandarin recorded the highest titratable acidity of 3.88% in contrast to 0.67 % for Sonbol. Studies of pollen grain fertility showed that Celiopatra and Sayed Marri varieties gave the highest pollen fertility (99.84%and 99.44% respectively). Contrarily, the highest pol-len sterility was found in Clementine variety (8.41%)

    Fortunella margarita Transcriptional Reprogramming Triggered by Xanthomonas citri subsp. citri

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    <p>Abstract</p> <p>Background</p> <p>Citrus canker disease caused by the bacterial pathogen <it>Xanthomonas citri </it>subsp. <it>citri (</it>Xcc) <it>has </it>become endemic in areas where high temperature, rain, humidity, and windy conditions provide a favourable environment for the dissemination of the bacterium. Xcc is pathogenic on many commercial citrus varieties but appears to elicit an incompatible reaction on the citrus relative <it>Fortunella margarita </it>Swing (kumquat), in the form of a very distinct delayed necrotic response. We have developed subtractive libraries enriched in sequences expressed in kumquat leaves during both early and late stages of the disease. The isolated differentially expressed transcripts were subsequently sequenced. Our results demonstrate how the use of microarray expression profiling can help assign roles to previously uncharacterized genes and elucidate plant pathogenesis-response related mechanisms. This can be considered to be a case study in a citrus relative where high throughput technologies were utilized to understand defence mechanisms in <it>Fortunella </it>and citrus at the molecular level.</p> <p>Results</p> <p><b>cDNAs from sequenced kumquat libraries (ESTs) made from subtracted RNA populations, healthy vs. infected, were used to make this microarray</b>. Of 2054 selected genes on a customized array, 317 were differentially expressed (P < 0.05) in Xcc challenged kumquat plants compared to mock-inoculated ones. This study identified components of the incompatible interaction such as reactive oxygen species (ROS) and programmed cell death (PCD). Common defence mechanisms and a number of resistance genes were also identified. In addition, there were a considerable number of differentially regulated genes that had no homologues in the databases. This could be an indication of either a specialized set of genes employed by kumquat in response to canker disease or new defence mechanisms in citrus.</p> <p>Conclusion</p> <p>Functional categorization of kumquat Xcc-responsive genes revealed an enhanced defence-related metabolism as well as a number of resistant response-specific genes in the kumquat transcriptome in response to Xcc inoculation. Gene expression profile(s) were analyzed to assemble a comprehensive and inclusive image of the molecular interaction in the kumquat/Xcc system. This was done in order to elucidate molecular mechanisms associated with the development of the hypersensitive response phenotype in kumquat leaves. These data will be used to perform comparisons among citrus species to evaluate means to enhance the host immune responses against bacterial diseases.</p

    Seroprevalence of SARS-CoV-2 (COVID-19) among Healthcare Workers in Saudi Arabia: Comparing Case and Control Hospitals

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    Healthcare workers (HCWs) stand at the frontline for fighting coronavirus disease 2019 (COVID-19) pandemic. This puts them at higher risk of acquiring the infection than other individuals in the community. Defining immunity status among health care workers is therefore of interest since it helps to mitigate the exposure risk. This study was conducted between May 20th and 30th, 2020. Eighty-five hospitals across Kingdom of Saudi Arabia were divided into 2 groups: COVID-19 referral hospitals are those to which RT-PCR-confirmed COVID-19 patients were admitted or referred for management (Case-hospitals). COVID-19 nonaffected hospitals where no COVID-19 patients had been admitted or managed and no HCW outbreak (Control hospitals). Next, seroprevalence of severe acute respiratory syndrome coronavirus 2 among HCWs was evaluated; there were 12,621 HCWs from the 85 hospitals. There were 61 case-hospitals with 9379 (74.3%) observations, and 24 control-hospitals with 3242 (25.7%) observations. The overall positivity rate by the immunoassay was 299 (2.36%) with a significant difference between the case-hospital (2.9%) and the control-group (0.8%) (P value <0.001). There was a wide variation in the positivity rate between regions and/or cities in Saudi Arabia, ranging from 0% to 6.31%. Of the serology positive samples, 100 samples were further tested using the SAS2pp neutralization assay; 92 (92%) samples showed neutralization activity. The seropositivity rate in Kingdom of Saudi Arabia is low and varies across different regions with higher positivity in case-hospitals than control-hospitals. The lack of neutralizing antibodies (NAb) in 8% of the tested samples could mean that assay is a more sensitive assay or that neutralization assay has a lower detection limits; or possibly that some samples had cross-reaction to spike protein of other coronaviruses in the assay, but these were not specific to neutralize severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

    Survival implications vs. complications: unraveling the impact of vitamin D adjunctive use in critically ill patients with COVID-19—A multicenter cohort study

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    BackgroundDespite insufficient evidence, vitamin D has been used as adjunctive therapy in critically ill patients with COVID-19. This study evaluates the effectiveness and safety of vitamin D as an adjunctive therapy in critically ill COVID-19 patients.MethodsA multicenter retrospective cohort study that included all adult COVID-19 patients admitted to the intensive care units (ICUs) between March 2020 and July 2021. Patients were categorized into two groups based on their vitamin D use throughout their ICU stay (control vs. vitamin D). The primary endpoint was in-hospital mortality. Secondary outcomes were the length of stay (LOS), mechanical ventilation (MV) duration, and ICU-acquired complications. Propensity score (PS) matching (1:1) was used based on the predefined criteria. Multivariable logistic, Cox proportional hazards, and negative binomial regression analyses were employed as appropriate.ResultsA total of 1,435 patients were included in the study. Vitamin D was initiated in 177 patients (12.3%), whereas 1,258 patients did not receive it. A total of 288 patients were matched (1:1) using PS. The in-hospital mortality showed no difference between patients who received vitamin D and the control group (HR 1.22, 95% CI 0.87–1.71; p = 0.26). However, MV duration and ICU LOS were longer in the vitamin D group (beta coefficient 0.24 (95% CI 0.00–0.47), p = 0.05 and beta coefficient 0.16 (95% CI −0.01 to 0.33), p = 0.07, respectively). As an exploratory outcome, patients who received vitamin D were more likely to develop major bleeding than those who did not [OR 3.48 (95% CI 1.10, 10.94), p = 0.03].ConclusionThe use of vitamin D as adjunctive therapy in COVID-19 critically ill patients was not associated with survival benefits but was linked with longer MV duration, ICU LOS, and higher odds of major bleeding

    Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

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    Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10&nbsp;years; 78.2% included were male with a median age of 37&nbsp;years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

    Attitudes and barriers towards conducting research amongst primary care physicians in Bahrain: a cross-sectional study

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    Abstract Background Research in primary care is essential for disease diagnosis, management and prevention in relation to the individuals, families and the community. This research aims to study the attitude of primary care physicians towards conducting research in Bahrain and to identify the main barriers encountered during research. Methods A cross-sectional study was conducted amongst 200 randomly selected primary care physicians registered in Ministry of Health affiliated primary healthcare centers in Bahrain. A self-administered validated questionnaire was adopted and used for data collection. Research data was analyzed using the Statistical Package for Social Sciences (SPSS) version 23. Results Primary care physicians had a positive attitude towards conducting research with a total mean score (SD) of 4.47(0.65) (on a scale from 1 to 5 with higher scores indicating more positive attitudes). The total mean score (SD) for barriers encountered by physicians during research was 3.34 (0.80). Insufficient research allotted time (76.5%), insufficient financial support (63%), lack of financial incentives (51%) and lack of statistical support (50%) were major barriers. Physicians designation and board certificate were significantly associated with attitudes and barriers towards research (P-value < 0.05). Conclusion The majority or primary care physicians had positive attitudes towards conducting research. The major difficulties faced by physicians in conducting research are: Insufficient research allotted time, lack of financial incentives and inadequate statistical support. The study addressed a gap in building research capacity which should be embraced by many institutions through partnership and collaboration

    Photodegradation of Carbol Fuchsin Dye Using an Fe2&minus;xCuxZr2&minus;xWxO7 Photocatalyst under Visible-Light Irradiation

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    Fe2&minus;xCuxZr2&minus;xWxO7 (x: 0, 0.05, 0.015) nanoparticles were synthesized following the Pechini method and characterized via X-ray diffraction (XRD), transmission electron microscopy (TEM), and diffuse reflectance spectroscopy (DRS) measurements to be used as photocatalysts in colored water remediation. All of the prepared materials were crystallized in a cubic fluorite phase as the major phase. The band gap was reduced upon doping with W6+ and Cu2+ from 1.96 eV to 1.47 eV for Fe1.85Cu0.15Zr1.85W0.15O7. Carbol fuchsin (CF) dye was used to determine the photocatalytic degradation efficiency of the prepared catalysts. Degradation efficiency was directly proportional to the dopant&rsquo;s concentration. Complete removal of 20 mg/L CF was achieved under optimal conditions (pH 9, and catalyst loading of 1.5 g/L) using Fe1.85Cu0.15Zr1.85W0.15O7. The degradation rate followed pseudo-first-order kinetics. The reusability for photocatalysts was tested five times, decreasing its efficiency by 4% after the fifth cycle, which indicates that the prepared Fe1.85Cu0.15Zr1.85W0.15O7 photocatalyst is a promising novel photocatalyst due to its superior efficiency in dye photodegradation
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