55 research outputs found

    Co-Production of Cellulase and Xylanase Enzymes By Thermophilic Bacillus subtilis 276NS

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    Co-production of thermostable extracellular cellulase and xylanase was investigated using bacterial soil isolate. To evaluate the effect of culture conditions on the c-oproduction of both enzymes by Bacillus subtilis 276NS (GenBank accession number JF801740), a Plackett-Burman fractional factorial design was applied. Among the tested variables, yeast extract, sucrose and incubation time were the most significant variables increased cellulase and xylanase productions. Both of xylan and CMC (Carboxymethyl Cellulose) induced the xylanse enzyme production. A near-optimum medium formulation was obtained which increased the cellulase and xylanase enzymes 5.7- and 1.08 –fold higher than the yield obtained with the basal medium, respectively. Thereafter, the response surface methodology was adopted to acquire the best process conditions among the selected variables (xylan, CMC and Yeast Extract (YE)) required for improving xylanase yield. The optimal combinations of the major medium constituents for xylanase production evaluated using non-linear optimization algorithm of EXCEL-solver, was as follows (g/L): D-sucrose, 10; xylan, 10.367, CMC, 10.535; (NH4)2SO4, 1.0; YE, 1.71; Tween-80, 0.4 and FeSO4, 0.25 mg/L, at pH 8.0, temperature 35◦C and incubation time 24h under shaking. The predicted optimum thermostable xylanase activity was 360 U/ml, which was around 4-times the activity with the basal medium

    UTILIZING WASTE HEAT FROM THE REFRIGERATION CYCLE BY USING A TWO-STAGE HEAT EXCHANGER

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    Refrigeration, and air conditioning systems are designed to transport heat from internal spaces or products and discard it into the surrounding. Refutation of heat might happen in a straight line to the air, as in the case of most conventional units of air-source, or to water flowing from a cooling tower. This heat is of a "low-grade diversity", it still signifies wasted energy. According to the viewpoint of energy conservation, it would be necessary to regain this heat in a serviceable form. In this research, a practical study aims to collect the heat emitted from the cooling condenser by 35% and exploit it in heating hot water for domestic purposes, in addition to other uses, including reducing the consumption of electrical energy as a result of exploiting and collecting waste heat, from cooling devices using a system consisting of two types of helical heat exchangers and two stages. The first stage consists of a tube-in-tube helical exchanger and the second stage includes a tube-in-shell heat exchanger using R410A refrigerant. The EES engineering equation solving program was used to solve the numerical equations that are used to solve problems related to thermodynamics, due to its high accuracy in solving equations, extracting values and graphs, and calculating the performance coefficient of the COP to obtain better efficiency for the work of the system, as it was found that the higher the temperature. As a result of increasing the flow rate of deionized water, the percentage of performance coefficient of COP has increased

    Syntheses, Structures and Biological Activity of Some Schiff Base Metal Complexes

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    اربع معقدات قاعدة شف ثنائية النواة جديدة [(MCl2)2L] = M} Fe (1), (2) Co, Cu (3), Sn (4) { ليكاند = 1,4-ثنائي فنيلين (ميثان دايين) ثنائي(ايثان ثنائي امين). حضرت بطريقة التفاعل المباشر بين اليكاند وعدد من هاليدات الفلزات. الصيغ التركيبية للمركبات اثبتت من خلال عدد من التقنيات الطيفية مكيف الاشعة تحت الحمراء وطيف الرنين النووي المغناطيسي وطيف الكتلة. حددت الفعالية الحيوية للمركبات تجاه عدد من العزلات البكتيرية السالبة والموجبة الغرام مثل العصية القولونية, الزوائف, العصيات, المكورات العنقودية, المسبحات العنقودية.Four new binuclear Schiff base metal complexes [(MCl2)2L] {M = Fe 1, Co 2, Cu 3, Sn 4, L = N,N’-1,4-Phenylenebis (methanylylidene) bis (ethane-1,2-diamine)} have been synthesized using direct reaction between proligand (L) and the corresponding metal chloride (FeCl2, CoCl2, CuCl2 and SnCl2). The structures of the complexes have been conclusively determined by a set of spectroscopic techniques (FT-IR, 1H-NMR, and mass spectra). Finally, the biological properties of the complexes have been investigated with a comparative approach against different species of bacteria (E. coli G-, Pseudomonas G-, Bacillus G+, Staphylococcus G+, and Streptococcus G+)

    Characterization of an isolated lactase enzyme produced by Bacillus licheniformis ALSZ2 as a potential pharmaceutical supplement for lactose intolerance

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    IntroductionLactose intolerance is a widespread problem that affects people of many different races all over the world. The following pharmacological supplements can improve the lives of those who suffer from this issue.MethodsThis work focused on lactase producer isolation and statistical design (Plackett–Burman, and BOX–Behnken) to maximize the effectiveness of environmental factors. A lactase-producing bacterium was chosen from a discovery of 100 strains in soil that had previously been polluted with dairy products. Plackett-Burman investigated fifteen variables.ResultsThe most critical variables that lead to increased lactase synthesis are glucose, peptone, and magnesium sulfate (MgSO4). The ideal process conditions for the creation of lactase yield among the stated variables were then determined using a BOX-Benken design. To establish a polynomial quadratic relationship between the three variables and lactase activity, the Box–Behnken design level was used. The EXCEL-solver nonlinear optimization technique was used to predict the best form for lactase production. The ideal temperature and pH levels have been determined, both before and after the lactase purification process, to achieve the highest performance of isolated lactase.ConclusionAccording to this study, Bacillus licheniformis is a perfect supply of the lactase enzyme (β -Galactosidase), It can be used as a product to assist people who have health issues due to lactose intolerance

    Regularized multiframe super-resolution image reconstruction using linear and nonlinear filters

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    The primary goal of the multiframe super-resolution image reconstruction is to produce an image with a higher resolution by integrating information extracted from a set of corresponding images with low resolution, which is used in various fields. However, super-resolution image reconstruction approaches are typically affected by annoying restorative artifacts, including blurring, noise, and staircasing effect. Accordingly, it is always difficult to balance between smoothness and edge preservation. In this paper, we intend to enhance the efficiency of multiframe super-resolution image reconstruction in order to optimize both analysis and human interpretation processes by improving the pictorial information and enhancing the automatic machine perception. As a result, we propose new approaches that firstly rely on estimating the initial high-resolution image through preprocessing of the reference low-resolution image based on median, mean, Lucy-Richardson, and Wiener filters. )is preprocessing stage is used to overcome the degradation present in the reference low-resolution image, which is a suitable kernel for producing the initial high-resolution image to be used in the reconstruction phase of the final image. then, L2 norm is employed for the data-fidelity term to minimize the residual among the predicted high-resolution image and the observed low-resolution images. Finally, bilateral total variation prior model is utilized to restrict the minimization function to a stable state of the generated HR image. )e experimental results of the synthetic data indicate that the proposed approaches have enhanced efficiency visually and quantitatively compared to other existing approaches

    Efficacy and safety of empagliflozin in type 2 diabetes mellitus Saudi patients as add-on to antidiabetic therapy: a prospective, open-label, observational study

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    The Saudi Food and Drug Authority (SFDA) approved sodium-glucose cotransporter-2 (SGLT2) inhibitors in 2018. The efficacy and safety of empagliflozin (EMPA) have been confirmed in the U.S., Europe, and Japan for patients with type 2 diabetes mellitus (T2DM); however, analogous evidence is lacking for Saudi T2DM patients. Therefore, the current study aimed to assess the efficacy and safety of EMPA in Saudi patients (n = 256) with T2DM. This is a 12-week prospective, open-label, observational study. Adult Saudi patients with T2DM who had not been treated with EMPA before enrolment were eligible. The exclusion criteria included T2DM patients less than 18 years of age, adults with type one diabetes, pregnant women, paediatric population. The results related to efficacy included a significant decrease in haemoglobin A1c (HbA1c) (adjusted mean difference −0.93% [95% confidence interval (CI) −0.32, −1.54]), significant improvements in fasting plasma glucose (FPG) (−2.28 mmol/L [95% CI −2.81, −1.75]), and a reduction in body weight (−0.874 kg [95% CI −4.36, −6.10]) following the administration of 25 mg of EMPA once daily as an add-on to ongoing antidiabetic therapy after 12 weeks. The primary safety endpoints were the change in the mean blood pressure (BP) values, which indicated significantly reduced systolic and diastolic BP (−3.85 mmHg [95% CI −6.81, −0.88] and −0.06 mmHg [95% CI −0.81, −0.88], respectively) and pulse rate (−1.18 [95% CI −0.79, −3.15]). In addition, kidney function was improved, with a significant reduction in the urine albumin/creatinine ratio (UACR) (−1.76 mg/g [95% CI −1.07, −34.25]) and a significant increase in the estimated glomerular filtration rate (eGFR) (3.54 mL/min/1.73 m2 [95% CI 2.78, 9.87]). Furthermore, EMPA reduced aminotransferases (ALT) in a pattern (reduction in ALT > AST). The adjusted mean difference in the change in ALT was −2.36 U/L [95% CI −1.031, −3.69], while it was −1.26 U/L [95% CI −0.3811, −2.357] for AST and −1.98 U/L [95% CI −0.44, −3.49] for GGT. Moreover, in the EMPA group, serum high-density lipoprotein (HDL) significantly increased (0.29 mmol/L [95% CI 0.74, 0.15]), whereas a nonsignificant increase was seen in low-density lipoprotein (LDL) (0.01 mmol/L [95% CI 0.19, 0.18]) along with a significant reduction in plasma triglyceride (TG) levels (−0.43 mmol/L [95% CI −0.31, −1.17]). Empagliflozin once daily is an efficacious and tolerable strategy for treating Saudi patients with insufficiently controlled T2DM as an add-on to ongoing antidiabetic therapy

    Association of Spermatogenic Failure with the b2/b3 Partial AZFc Deletion

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    Infertility affects around 1 in 10 men and in most cases the cause is unknown. The Y chromosome plays an important role in spermatogenesis and specific deletions of this chromosome, the AZF deletions, are associated with spermatogenic failure. Recently partial AZF deletions have been described but their association with spermatogenic failure is unclear. Here we screened a total of 339 men with idiopathic spermatogenic failure, and 256 normozoospermic ancestry-matched men for chromosome microdeletions including AZFa, AZFb, AZFc, and the AZFc partial deletions (gr/gr, b1/b3 and b2/b3)

    Multinational prospective cohort study of rates and risk factors for ventilator-associated pneumonia over 24 years in 42 countries of Asia, Africa, Eastern Europe, Latin America, and the Middle East: Findings of the International Nosocomial Infection Control Consortium (INICC)

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    Objective: Rates of ventilator-associated pneumonia (VAP) in low- and middle-income countries (LMIC) are several times above those of high-income countries. The objective of this study was to identify risk factors (RFs) for VAP cases in ICUs of LMICs. Design: Prospective cohort study. Setting: This study was conducted across 743 ICUs of 282 hospitals in 144 cities in 42 Asian, African, European, Latin American, and Middle Eastern countries. Participants: The study included patients admitted to ICUs across 24 years. Results: In total, 289,643 patients were followed during 1,951,405 patient days and acquired 8,236 VAPs. We analyzed 10 independent variables. Multiple logistic regression identified the following independent VAP RFs: male sex (adjusted odds ratio [aOR], 1.22; 95% confidence interval [CI], 1.16-1.28; P <.0001); longer length of stay (LOS), which increased the risk 7% per day (aOR, 1.07; 95% CI, 1.07-1.08; P <.0001); mechanical ventilation (MV) utilization ratio (aOR, 1.27; 95% CI, 1.23-1.31; P <.0001); continuous positive airway pressure (CPAP), which was associated with the highest risk (aOR, 13.38; 95% CI, 11.57-15.48; P <.0001)Revisión por pare

    Global Retinoblastoma Presentation and Analysis by National Income Level.

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    Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4%) were female. Most patients (n = 3685 [84.7%]) were from low- and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 [62.8%]), followed by strabismus (n = 429 [10.2%]) and proptosis (n = 309 [7.4%]). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 [95% CI, 12.94-24.80], and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 [95% CI, 4.30-7.68]). Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs
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