QT Interval and QT Dispersion in Patients Undergoing Hemodialysis: Revisiting the Old Theory

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Characterization of immobilized alkaline cyclodextringlycosyltransferase from a newly isolated Bacillus agaradhaerens KSU-A11

Alkaliphilic bacteria were isolated from soil and water samples obtained from Egyptian soda lakes (Wadi Natrun area, Egypt). Screening for cyclodextrin glycosyltransferase (CGTase)-producing alkaliphilic bacteria resulted in isolation of 10 positive strains. Strain KSU-A11 was selected as the best CGTase producer (2.1 U/ml). 16S rDNA sequence analysis identified the KSU-A11strain as Bacillus agaradhaerens. CGTase was partially purified using starch adsorption technique. The partially purified CGTase was immobilized on chitin by covalent binding tecnique using cross linking reaction with high immobilization yield (85%). The properties of the free and immobilized CGTase were determined. The optimum pH of the immobilized enzyme was slightly higher than that of the free enzyme at pH 10 and 10.5, respectively. In addition, both free and immobilized enzyme retained 94 to 100% of its initial activity over a wide pH range (pH 6.0 to 11.0). The enzymatic activity of both free and immobilized CGTase was highest at temperature 50°C; however, the relative activities of the immobilized CGTase were slightly higher than those of the free enzyme. Furthermore, investigation of thermostability of the enzyme indicated that the immobilization process of CGTase on chitin significantly protected the enzyme against thermo-inactivation. Kinetic parameters, Km and Vmax, values for free and immobilized enzymes were estimated and while there was no change in the Vmax value (83.3 μmol/min. mg) for both free and immobilized CGTase, the Km of the enzyme increased from 14.28 to 20 mg/ml upon immobilization. The immobilization of the enzyme showed high operational stability by retaining almost 50% of the initial activity after nine uses.Key words: Cyclodextrin glycosyltransferase, Bacillus agaradhaerens, immobilization, chitin, alkaliphiles

Development Of Health Care Systems in Subareas of KSA Using GIS Concept

The present study was directed to show how Geographical Information Systems (GIS) can be used to support health planning and demanding on a micro-scale and explore the possibilities of using GIS for health care services in hospitals in Saudi Arabia subareas. The first part of this work explained the issues that affect a local health care planning and monitoring of catchment area and facilities management. Each one of these issues was covered using several GIS functions including network analysis and spatial data analysis. The second part defined GIS and its possible application in the health care field. In this section, the relevant GIS functions have also been explained. In response, alternative sources were used, such as Google Earth, printed maps and information gathered on the ground by GPS. The third part discussed the creation and implementation of GIS application models, which was made for a local health care center in Makah AlMokaramah region and Taif city in Saudi Arabia. All the produced models can be applied in any private or public hospital in Makkahh region and Taif city. They can be used to build a spatial decision making support system for hospitals in Taif region and serves five local health services neighborhoods named as Tarabah, AlKhurma, Rania, Zulam and Al-Moya. The most important results of this research were the determination of geographic locations of healthcare institutions, identifying ways and distances to reach the nearest access roads to these institutions. As well as being able to extract administrative regions on a large number of population, hospitals, health centers, number of beds, number of doctors and number of nurses. One of the recommendations of this research the need of using GIS and GPS (Global Positional System) to determine the locations of health institutions on a number of sites

Designing and Implementing of Electronic Health Record System in Ksa using Sql & Asp.Net

Electronic health record (EHR) rapid progress for reporting electronic data storage that employs uniform data standards will enable health care organizations to respond more quickly to federal state, and private reporting requirements, including those that support patient safety and disease surveillance. An examination of many hospitals that recently implemented in King Saudi Arabia (KSA). A little of electronic health record (EHR) system finds that clinical and administrative leaders built EHR adoption into their strategic plans to integrate, inpatient and outpatient care system and a provide  continuum of coordinated services. Using Relational Data Base Management Systems (RDBMS) with eXtend Marker Language (XML) Systems and ASP.NET as web based system. Successful implementation depended on: strong leadership, full involvement of clinical staff in design and implementation, mandatory staff training, and strict adherence to timeline and budget. The EHR systems facilitate patient safety and quality development through; use of checklists, alerts, and predictive tools embedded clinical guidelines that promote standardized, evidence-based practices electronic prescribing and test-ordering that reduces errors and redundancy and discrete data fields that foster use of performance dashboards and compliance reports. The proposed system will be developed using ASP.NET as a technology of web based system. In this paper; most of the services, enjoyed on the Web are provided by web database applications and using .net technology. Such as, Web-based email, online shopping, forums and bulletin boards, corporate web sites, and sports and news portals are all database-driven. The main goals in this work, building a modern web site of electronic health record system in KSA hospitals. Keywords: XML, RDBMS, EHR , EMR, EPR, GIS, PH

A Systematic Design of a Compact Wideband Hybrid Directional Coupler Based on Printed RGW Technology

Printed ridge gap waveguide (PRGW) is considered among the state of art guiding technologies due to its low signal distortion and low loss at Millimeter Wave (mmWave) spectrum, which motivates the research community to use this guiding structure as a host technology for various passive microwave and mmWave components. One of the most important passive components used in antenna beam-switching networks is the quadrature hybrid directional coupler providing signal power division with 90° phase shift. A featured design of a broadband and compact PRGW hybrid coupler is propose in this paper. A novel design methodology, based on mode analysis, is introduced to design the objective coupler. The proposed design is suitable for mmWave applications with small electrical dimensions ( 1.2λo×1.2λo ), low loss, and wide bandwidth. The proposed hybrid coupler is fabricated on Roger/RT 6002 substrate material of thickness 0.762 mm. The measured results highlight that the coupler can provide a good return loss with a bandwidth of 26.5% at 30 GHz and isolation beyond 15 dB. The measured phase difference between the coupler output ports is equal 90∘± 5∘ through the interested operating bandwidth. A clear agreement between the simulated and the measured results over the assigned operating bandwidth has been illustrated

Immobilization of cyclodextrin glucanotransferase on aminopropyl-functionalized silica-coated superparamagnetic nanoparticles

Background: Cyclodextrin glycosyltransferase (CGTase) from Amphibacillus sp. NPST-10 was successfully covalently immobilized on aminopropyl-functionalized silica coated superparamagnetic nanoparticles; and the properties of immobilized enzyme were investigated. The synthesis process included preparing of core magnetic magnetite (Fe3O4) nanoparticles using solvothermal synthesis; followed by coating of Fe3O4 nanoparticles with dense amino-functionalized silica (NH2-SiO2) layer using in situ functionalization method. The structure of synthesized Fe3O4@NH2-SiO2 nanoparticles was characterized using TEM, XRD, and FT-IR analysis. Fe3O4@NH2-SiO2 nanoparticles were further activated by gluteraaldehyde as bifunctional cross linker, and the activated nanoparticles were used for CGTase immobilization by covalent attachment. Results: Magnetite nanoparticles was successfully synthesized and coated with and amino functionalized silica layer (Fe3O4/NH2-SiO2), with particle size of 50-70 nm. The silica coated magnetite nanoparticles showed with saturation magnetization of 65 emug-1, and can be quickly recovered from the bulk solution using an external magnet within 10 sec. The activated support was effective for CGTase immobilization, which was confirmed by comparison of FT-IR spectra of free and immobilized enzyme. The applied approach for support preparation, activation, and optimization of immobilization conditions, led to high yields of CGTase immobilization (92.3%), activity recovery (73%), and loading efficiency (95.2%); which is one of the highest so far reported for CGTase. Immobilized enzyme showed shift in the optimal temperature from 50 to 55\ubaC, and significant enhancement in the thermal stability compared with free enzyme. The optimum pH for enzyme activity was pH 8 and pH 7.5 for free and immobilized CGTase, respectively, with slight improvement of pH stability of immobilized enzyme. Furthermore, kinetic studies revealed that immobilized CGTase had higher affinity toward substrate; with km values of 1.18 \ub1 0.05 mg/ml and 1.75 \ub1 0.07 mg/ml for immobilized and free CGTase, respectively. Immobilized CGTase retained 87% and 67 of its initial activity after 5 and 10 repeated batches reaction, indicating that immobilized CGTase on Fe3O4/NH2-SiO2 had good durability and magnetic recovery. Conclusion: The improvement in kinetic and stability parameters of immobilized CGTase makes the proposed method a suitable candidate for industrial applications of CGTase. To best of our knowledge, this is the first report about CGTase immobilization on silica coated magnetite nanoparticles

Cyclodextrin glucanotransferase immobilization onto functionalized magnetic double mesoporous core\u2013shell silica nanospheres

Background: Cyclodextrin glucanotransferase (CGTase) from Amphibacillus sp. NPST-10 was covalently immobilized onto amino-functionalized magnetic double mesoporous core\u2013shell silica nanospheres (mag@d-SiO2@m-SiO2-NH2), and the properties of the immobilized enzyme were investigated. The synthesis process of the nanospheres included preparing core magnetic magnetite (Fe3O4) nanoparticles, coating the Fe3O4 with a dense silica layer, followed by further coating with functionalized or non-functionalized mesoporous silica shell. The structure of the synthesized nanospheres was characterized using TEM, XRD, and FT-IR analyses. CGTase was immobilized onto the functionalized and non-functionalized nanospheres by covalent attachment and physical adsorption. Results: The results indicated that the enzyme immobilization by covalent attachment onto the activated mag@d-SiO2@m-SiO2-NH2, prepared using anionic surfactant, showed highest immobilization yield (98.1%), loading efficiency (96.2%), and loading capacity 58 \u3bcg protein [CGTase]/mg [nanoparticles]) which were among the highest yields reported so far for CGTase. Compared with the free enzyme, the immobilized CGTase demonstrated a shift in the optimal temperature from 50\ub0C to 50\u201355\ub0C, and showed a significant enhancement in the enzyme thermal stability. The optimum pH values for the activity of the free and immobilized CGTase were pH 8 and pH 8.5, respectively, and there was a significant improvement in pH stability of the immobilized enzyme. Moreover, the immobilized CGTase exhibited good operational stability, retaining 56% of the initial activity after reutilizations of ten successive cycles. Conclusion: The enhancement of CGTase properties upon immobilization suggested that the applied nano-structured carriers and immobilization protocol are promising approach for industrial bioprocess for production of cyclodextrins using immobilized CGTase

Isolation and characterization of novel potent Cr(VI) reducing alkaliphilic Amphibacillus sp. KSUCr3 from hypersaline soda lakes

A strain KSUCr3 with extremely high Cr(VI)-reducing ability under alkaline conditions was isolated from hypersaline soda lakes and identified as Amphibacillus sp. on the basis of 16S rRNA gene sequence analysis. The results showed that Amphibacillus sp. strain KSUCr3 was tolerance to very high Cr(VI) concentration (75 mM) in addition to high tolerance to other heavy metals including Ni2+ (100 mM), Mo2+ (75 mM), Co2+ (5 mM), Mn2+ (100 mM), Zn2+ (2 mM), Cu2+ (2 mM) and Pb (75 mM). Strain KSUCr3 was shown to be of a high efficiency in detoxifying chromate, as it could rapidly reduce 5 mM of Cr(VI) to a non detectable level over 24 hrs. In addition, strain KSUCr3 could reduce Cr(VI) efficiently over a wide range of initial Cr(VI) concentrations (1-10 mM) in alkaline medium under aerobic conditions without significant effect on the bacterial growth. Addition of glucose, NaCl and Na2CO3 to the culture medium caused a dramatic increase in Cr(VI)-reduction by Amphibacillus sp. strain KSUCr3. The maximum chromate removal was exhibited in alkaline medium containing 1.5% Na2CO3, 0.8% glucose, and 1.2% NaCl, at incubation temperature of 40\ub0C and shaking of 100 rpm. Under optimum Cr(VI) reduction conditions, Cr(VI) reduction rate reached 237 \u3bcMh1 which is one of the highest Cr(VI) reduction rate, under alkaline conditions and high salt concentration, compared to other microorganisms that has been reported so far. Furthermore, the presence of other metals, such as Ni2+, Co2+, Cu2+ and Mn2+ slightly stimulated Cr(VI)-reduction ability by the strain KSUCr3.The isolate, Amphibacillus sp. strain KSUCr3, exhibited an ability to repeatedly reduce hexavalent chromium without any amendment of nutrients, suggesting its potential application in continuous bioremediation of Cr(VI). The results also revealed the possible isolation of potent heavy metals resistant bacteria from extreme environment such as hypersaline soda lakes

Effects of substrates and reaction conditions on production of cyclodextrins using cyclodextrin glucanotransferase from newly isolated Bacillus agaradhaerens KSU-A11

The effects of reaction conditions on cyclodextrins (CDs) production by CGTase from newly isolated Bacillus agaradhaerens KSU-A11 is reported. Among six types of starch tested, potato starch gave highest starch conversion into CDs. In addition, CDs yield was about three fold higher when using gelatinized potato starch in comparison to raw starch. The total CDs production was increased with increasing pH, showing maximum starch conversion at pH 10. Furthermore, the proportion of \u3b3-CD was relatively higher under slightly acidic-neutral conditions than at alkaline pH with a maximum proportion of 35.6% at pH 7 compared to 7.6% at pH 10. Maximum starch conversion into CDs was seen at reaction temperature of 55\ub0C. Lower reaction temperature led to higher proportion of \u3b3-CD with maximum percentage at 35\ub0C. Cyclization reaction was significantly promoted in the presence CaCl2 (10 mM), while in the presence of ethyl alcohol there was significant decrease in CD production particularly at high concentration. f-CD was the major product up to 1 hr reaction period with traces of \u3b1-CD and no detectable \u3b3-CD. However, as the reaction proceed, \u3b3-CD started to be synthesised and \u3b1-CD concentration increased up to 4 hrs, where the CDs ratios were 0.27:0.65:0.07 for \u3b1-CD: f-CD:\u3b3-CD, respectively. In addition, optimum CGTase/starch ratio was obtained at 80 U/g starch, showing highest starch conversion into CDs. All the parameters involved have been shown to affect the products yield and/or specificity of B. agaradhaerens KSU-A11 CGTase

Production of extracellular alkaline protease by new halotolerant alkaliphilic Bacillus sp. NPST-AK15 isolated from hyper saline soda lakes

Background: Alkaline proteases are among the most important classes of industrial hydrolytic enzymes. The industrial demand for alkaline proteases with favorable properties continues to enhance the search for new enzymes. The present study focused on isolation of new alkaline producing alkaliphilic bacteria from hyper saline soda lakes and optimization of the enzyme production. Results: A new potent alkaline protease producing halotolerant alkaliphilic isolate NPST-AK15 was isolated from hyper saline soda lakes, which affiliated to Bacillus sp. based on 16S rRNA gene analysis. Organic nitrogen supported enzyme production showing maximum yield using yeast extract, and as a carbon source, fructose gave maximum protease production. NPST-AK15 can grow over a broad range of NaCl concentrations (0\u201320%), showing maximal growth and enzyme production at 0\u20135%, indicated the halotolerant nature of this bacterium. Ba and Ca enhanced enzyme production by 1.6 and 1.3 fold respectively. The optimum temperature and pH for both enzyme production and cell growth were at 40\ub0C and pH 11, respectively. Alkaline protease secretion was coherent with the growth pattern, started at beginning of the exponential phase and reached maximal in mid stationary phase (36 h). Conclusions: A newhalotolerant alkaliphilic alkaline protease producing Bacillus sp.NPST-AK15 was isolated from soda lakes. Optimization of various fermentation parameters resulted in an increase of enzyme yield by 22.8 fold, indicating the significance of optimization of the fermentation parameters to obtain commercial yield of the enzyme. NPST-AK15 and its extracellular alkaline protease with salt tolerance signify their potential applicability in the laundry industry and other applications