113 research outputs found

    Novel epoxy activated hydrogels for solving lactose intolerance

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    "Lactose intolerance" is a medical problem for almost 70% of the world population. Milk and dairy products contain 5-10% w/v lactose. Hydrolysis of lactose by immobilized lactase is an industrial solution. In this work, we succeeded to increase the lactase loading capacity to more than 3-fold to 36.3 U/g gel using epoxy activated hydrogels compared to 11 U/g gel using aldehyde activated carrageenan. The hydrogel's mode of interaction was proven by FTIR, DSC, and TGA. The high activity of the epoxy group was regarded to its ability to attach to the enzyme's -SH, -NH, and -OH groups, whereas the aldehyde group could only bind to the enzyme's -NH2 group. The optimum conditions for immobilization such as epoxy chain length and enzyme concentration have been studied. Furthermore, the optimum enzyme conditions were also deliberated and showed better stability for the immobilized enzyme and the Michaelis constants, Km and Vmax, were doubled. Results revealed also that both free and immobilized enzymes reached their maximum rate of lactose conversion after 2 h, albeit, the aldehyde activated hydrogel could only reach 63% of the free enzyme. In brief, the epoxy activated hydrogels are more efficient in immobilizing more enzymes than the aldehyde activated hydrogel

    Cutting-edge biotechnological advancement in islet delivery using pancreatic and cellular approaches.

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    There are approximately 1 billion prediabetic people worldwide, and the global cost for diabetes mellitus (DM) is estimated to be $825 billion. In regard to Type 1 DM, transplanting a whole pancreas or its islets has gained the attention of researchers in the last few decades. Recent studies showed that islet transplantation (ILT) containing insulin-producing β cells is the most notable advancement cure for Type 1 DM. However, this procedure has been hindered by shortage and lack of sufficient islet donors and the need for long-term immunosuppression of any potential graft rejection. The strategy of encapsulation may avoid the rejection of stem-cell-derived allogeneic islets or xenogeneic islets. This review article describes various biotechnology features in encapsulation-of-islet-cell therapy for humans, including the use of bile acids

    Modeling and Analysis of Pavement-Vehicle Interaction Dynamics for Pavement Distress Prediction

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    Increased road traffic combined with heavy vehicle loads lead to deterioration and distress of pavements and consequently reduces the life span of the paved roads. As a result, large amounts of financial and labor resources are spent every year to improve and maintain road infrastructures around the world. Traditionally, vehicle and pavement dynamics are treated as two separate areas of research. However, they are strongly coupled together through their contact points. Thus, one of the major concerns is to develop a more reliable dynamic pavement-vehicle interaction model to investigate and evaluate accurately both vehicle and pavement responses, and also to examine the pavement distress due to the severity of traffic loads. One of the most important distress modes in pavements is fatigue cracking. Despite the fact that there have been considerable efforts in recent years in fatigue performance evaluation and the design of flexible pavements, there is still a need for further studies in predicting fatigue cracking in terms of damage distribution considering the uncertainty and variability associated with the input parameters of pavement-vehicle interaction and traffic load repetitions. The main objective of this research study is to carry out an in-depth investigation of the dynamics of the pavement-vehicle interaction and the effect of coupling action on system response, as well as fatigue study of the pavement due to repeated traffic loads. The response of the pavement-vehicle coupled system supported by a linear visco-elastic foundation has been investigated. The vehicle is modeled as a two-degree-of-freedom quarter-vehicle model, and the pavement-foundation system is described by a simply supported Euler-Bernoulli beam resting on Pasternak foundation, while the tire is coupled to the flexible pavement with a single point contact. Galerkin method has been utilized to develop the governing differential equations of motion. Direct numerical integration approach based on implicit Newmark linear average acceleration technique has been used to solve the governing differential equations in order to evaluate the response of the coupled system. Results have been validated with previous research work and also compared with those of conventional uncoupled system. The effects of different parameters such as vehicle speed, road roughness, soil stiffness and suspension damping on the responses are then investigated. For the fatigue study of flexible pavements, a methodology, for modeling pavement damage and predicting fatigue cracking of flexible pavements is presented. The methodology is based on the combination of deterministic method and stochastic approach using Palmgren-Miner’s hypothesis in which Poisson process is employed to characterize the actual repetitions of traffic load. Different models are then presented to estimate the fatigue life of the pavement surface layer. The results are compared and discussed

    Clinical and Histologic Evaluation of Using Block Xenograft Combined With Leukocyte-Platelet Rich Fibrin (L-PRF) Versus Intraoral Autogenous Bone Block Graft With L-PRF in Treating Localized Ridge Defects: A Randomized Clinical Trial

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    Background: Augmentation of vertical bone defects remains the corner stone in periodontal tissue engineering. The amount and quality of alveolar bone available in all dimensions affects the success of dental implants for restoration of edentulous areas. Adequate and healthy bone supports the degree of osseointegration which in turn affects the long-term success of oral implants. The primary aim of the study was to histologically evaluate autogenous block grafts versus synthetic block grafts for the treatment of atrophic vertical and horizontal bony defects (Siebert Class III) in the anterior esthetic zone of the mouth. The secondary aim was to clinically and radiographically evaluate the outcomes of the procedure. Methods: This was a randomized controlled clinical study with a statistically determined sample size of 10 patients per group and a total of 20 patients in both groups. Patients with vertical and horizontal bone loss were enrolled from the Department of Oral Medicine, Periodontology, and Oral Diagnosis of Ain Shams University and Misr International University. Bone augmentation procedures were performed using two techniques: autogenous bone block graft and xenograft bone block graft both with leukocyte-platelet rich fibrin (L-PRF). Results: Both autogenous and xenograft blocks in conjunction with L-PRF had a significant effect on vertical bone augmentation in cases of atrophic ridges in the esthetic region. Conclusion: Both autogenous and xenograft bone blocks in conjunction with L-PRF have a significant effect on vertical bone augmentation in cases of atrophic ridges in the esthetic region

    Sildenafil citrate for the management of asymmetrical intrauterine growth restriction and its effect on umbilical artery Doppler

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    Background: Asymmetrical intrauterine growth restriction IUGR occurs when there is uteroplacental insufficiency. Sildenafil citrate phosphodiasterase-5 inhibito is a potent vasodilator, which selectively inhibits phosphodiesterase-5 and, as a consequence, enhances the action of cyclic guanosine monophosphate which is the second messenger of NO. Hence, the trial was used for improving uteroplacental perfusion through enhancing vasodilatation of myometrial small arteries boosting flow within uteroplacental bed. The aim was to evaluate the efficacy of adding sildenafil citrate to low dose aspirin in treatment of asymmetrical IUGR through its effect on uteroplacental blood flow guided by Doppler ultrasound.Methods: Our study was a prospective double-blinded, randomized, controlled trial. Recruitment of participating women was from the obstetric outpatient clinic of Aswan university hospital. 100 patients included in the study and randomized in two groups. The first group was 50 patients assigned sildenafil with low dose aspirin and the second group was 50 patients assigned placebo with low dose aspirin.Results: As regard the outcomes, the study demonstrated that using of SC and LDA were effective in increasing estimated fetal weight and in improvement of umbilical artery umbilical artery Doppler (UAD) indices RI and PI for pregnancy complicated with IUGR compared with the control group.Conclusions: Sildenafil citrate is a promising treatment for IUGR fetuses with prolongation of pregnancy and improvement of fetal birth weight, umblical Doppler indices UDI, decreases days needed in PCU

    Immobilization of halophilic Aspergillus awamori EM66 exochitinase on grafted k-carrageenan-alginate beads

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    A novel extreme halophilic exochitinase enzyme was produced by honey isolate Aspergillus awamori EM66. The enzyme was immobilized successfully on k-carrageenan-alginate gel carrier (CA) with 93 % immobilization yield. The immobilization process significantly improved the enzyme specific activity 2.6-fold compared to the free form. The significant factors influencing the immobilization process such as enzyme protein concentration and loading time were studied. Distinguishable characteristics of optimum pH and temperature, stability at different temperatures and NaCl tolerance for free and immobilized enzyme were studied. The immobilization process improved optimum temperature from 35 to 45 °C. The immobilized enzyme retained 76.70 % of its activity after 2 h at 75 °C compared to complete loss of activity for the free enzyme. The reusability test proved the durability of the CA gel beads for 28 cycles without losing its activity

    Sexual Dysfunction in Jordanian Diabetic Women

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    OBJECTIVE—To estimate the prevalence of female sexual dysfunction (FSD) in diabetic and nondiabetic Jordanian women

    Investigating the Unexpected Behavior for the Release Kinetics of Brilliant Blue Encapsulated into Calcium Alginate Beads

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    This work is focused on investigating the unexpected behavior for the release kinetics of brilliant blue (BB) encapsulated into calcium alginate beads. By increasing the alginate concentration from 1-3% (w/v), the release of BB over time was found to follow two different behaviors. For the first two hours, the order was 1% > 2% > 3%, after which it was as follow: 1% > 3% > 2%. The unanticipated increase in BB release using 3% (w/v) alginate beads after two hours over that of 2% (w/v) alginate was examined by the swelling and bursting tests. The results were showing clear evidences by data and image the unusual behavior of 3% (w/v) alginate beads at two hours of swelling. This unexpected behavior for the 3% (w/v) alginate beads might be due to the higher osmotic pressure inside the beads. Overall, 2% (w/v) calcium alginate beads were considered to be the optimum formulation showing an excellent carrier for targeting drugs to the intestine, where the swelling of the beads were 60 % in the acidic medium, it was 5000 % in the alkaline medium

    Neuroprotective effect of ranolazine improves behavioral discrepancies in a rat model of scopolamine-induced dementia

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    BackgroundRanolazine (Rn), an antianginal agent, acts in the central nervous system and has been used as a potential treatment agent for pain and epileptic disorders. Alzheimer’s disease (AD) is one of the most prevalent neurodegenerative diseases and the leading factor in dementia in the elderly.AimWe examined the impact of Rn on scopolamine (Sco)-induced dementia in rats.MethodsThirty-two albino male rats were divided into four groups: control, Rn, Sco, and Rn + Sco.ResultsA significant decrease in the escape latency in the Morris water maze test after pre-treatment with Rn explained better learning and memory in rats. Additionally, Rn significantly upregulated the activities of the antioxidant enzymes in the treated group compared to the Sco group but substantially reduced acetylcholinesterase activity levels in the hippocampus. Moreover, Rn dramatically reduced interleukin-1 β (IL-1β) and IL-6 and upregulated the gene expression of brain-derived neurotrophic factor (BDNF). Furthermore, in the Sco group, the hippocampal tissue’s immunohistochemical reaction of Tau and glial factor activating protein (GFAP) was significantly increased in addition to the upregulation of the Caspase-3 gene expression, which was markedly improved by pre-treatment with Rn. The majority of pyramidal neurons had large vesicular nuclei with prominent nucleoli and appeared to be more or less normal, reflecting the all-beneficial effects of Rn when the hippocampal tissue was examined under a microscope.ConclusionOur findings indicated that Rn, through its antioxidative, anti-inflammatory, and anti-apoptotic effects, as well as the control of the expression of GFAP, BDNF, and Tau proteins, has a novel neuroprotective impact against scopolamine-induced dementia in rats

    Single-Step Production of a Recyclable Nanobiocatalyst for Organophosphate Pesticides Biodegradation Using Functionalized Bacterial Magnetosomes

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    Enzymes are versatile catalysts in laboratories and on an industrial scale; improving their immobilization would be beneficial to broadening their applicability and ensuring their (re)use. Lipid-coated nano-magnets produced by magnetotactic bacteria are suitable for a universally applicable single-step method of enzyme immobilization. By genetically functionalizing the membrane surrounding these magnetite particles with a phosphohydrolase, we engineered an easy-to-purify, robust and recyclable biocatalyst to degrade ethyl-paraoxon, a commonly used pesticide. For this, we genetically fused the opd gene from Flavobacterium sp. ATCC 27551 encoding a paraoxonase to mamC, an abundant protein of the magnetosome membrane in Magnetospirillum magneticum AMB-1. The MamC protein acts as an anchor for the paraoxonase to the magnetosome surface, thus producing magnetic nanoparticles displaying phosphohydrolase activity. Magnetosomes functionalized with Opd were easily recovered from genetically modified AMB-1 cells: after cellular disruption with a French press, the magnetic nanoparticles are purified using a commercially available magnetic separation system. The catalytic properties of the immobilized Opd were measured on ethyl-paraoxon hydrolysis: they are comparable with the purified enzyme, with Km (and kcat) values of 58 µM (and 178 s−1) and 43 µM (and 314 s−1) for the immobilized and purified enzyme respectively. The Opd, a metalloenzyme requiring a zinc cofactor, is thus properly matured in AMB-1. The recycling of the functionalized magnetosomes was investigated and their catalytic activity proved to be stable over repeated use for pesticide degradation. In this study, we demonstrate the easy production of functionalized magnetic nanoparticles with suitably genetically modified magnetotactic bacteria that are efficient as a reusable nanobiocatalyst for pesticides bioremediation in contaminated effluents
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