Immobilized Research Articles

Тест-система для определения сульфидов в водах на основе вискозы с иммобилизованным хлоридом кадмия

Тест-система для определения сульфидов в водах на основе вискозы с иммобилизованным хлоридом кадмия

Electrical evaluation of DNA immobilized between triangular-shaped electrodes

Electrical evaluation of DNA immobilized between triangular-shaped electrodes

Immobilization of Thrombin to Alginate Gel and in vitro Application of Immobilized Thrombin

Immobilization of Thrombin to Alginate Gel and in vitro Application of Immobilized Thrombin

Active exercise on immobilization-induced contractured rat knees develops arthrogenic joint contracture with pathological changes.

This study investigated the effects of treadmill walking during remobilization on range of motion (ROM) and histopathology in rat knee joints, which were immobilized for 3 wk in a flexed position. After fixator removal, rats were divided into a no-intervention (RM) group and a group forced to walk on a treadmill daily at 12 m/min for 60 min (WALK group). Passive knee extension ROMs were measured before (m-ROM) and after (a-ROM) knee flexor myotomy on the first and last day of a 7-day remobilization period, with m-ROM mainly reflecting myogenic factors and a-ROM reflecting arthrogenic factors. Knee joints were histologically analyzed and gene expression of inflammatory or fibrosis-related mediators in the posterior joint capsule were examined. m-ROM and a-ROM restrictions were established after immobilization. m-ROM significantly increased following the remobilization period both in RM and WALK groups compared with that of immobilized (IM) group. Conversely, a-ROM decreased following the remobilization period in both RM and WALK groups compared with that of IM group. Importantly, a-ROM was smaller in the WALK group than the RM group. Remobilization without intervention induced inflammatory and fibrotic reactions in the posterior joint capsule after 1 and 7 days. Treadmill walking promoted these reactions and also increased the expression of fibrosis-related TGF-β1 and collagen type I and III genes. While free movement after immobilization improved myogenic contracture, arthrogenic contracture worsened. Treadmill walking further aggravated arthrogenic contracture through amplified inflammatory and fibrotic reactions. Thus active exercise immediately after immobilization may not improve immobilization-induced joint contracture. NEW & NOTEWORTHY In clinical practice, it is widely accepted that facilitation of joint movements is effective in improving immobilization-induced joint contracture. However, whether active exercises improve arthrogenic contracture is not known. In this study, we revealed that treadmill walking further promoted remobilization-induced progression of arthrogenic contracture. To our knowledge, this is the first study demonstrating no favorable effect of active exercise on immobilization-induced arthrogenic contracture.

Photodegradation of Methylcyclohexane in Two Phases with Modified-titania Immobilized on Pumice

Photodegradation of Methylcyclohexane in Two Phases with Modified-titania Immobilized on Pumice

Enhanced Bio-Immobilization of Pb Contaminated Soil by Immobilized Bacteria with Biochar as Carrier

Enhanced Bio-Immobilization of Pb Contaminated Soil by Immobilized Bacteria with Biochar as Carrier

Septicemia Poisoning Detection at Vascular by Copper Immobilized Macro Probe

Septicemia Poisoning Detection at Vascular by Copper Immobilized Macro Probe

Prophylactic Effects of Propranolol versus the Standard Therapy on a New Model of Disuse Osteoporosis in Rats.

Disuse by bed rest, limb immobilization, or space flight causes rapid bone loss by arresting bone formation and accelerating bone resorption. Propranolol (a non-selective β-adrenergic antagonist) has been shown to improve bone properties by increasing bone formation and decreasing bone resorption in an ovariectomy-induced rat model. However, no studies have yet compared the osteoprotective properties of propranolol with well-accepted therapeutic interventions for the treatment and prevention of immobilization/disuse osteoporosis. To clarify this, we investigated the effects of propranolol compared with zoledronic acid and alfacalcidol in a new animal model of immobilization/disuse osteoporosis. Three-month-old male Wistar rats were divided into five groups with six animals in each group: (1) immobilized (IMM) control; (2) normal control; (3) IMM + zoledronic acid (50 μg/kg, intravenous single dose); (4) IMM + alfacalcidol (0.5 μg/kg, per oral daily); (5) IMM + propranolol (0.1 mg/kg, subcutaneously 5 days/week) for 10 weeks. In groups 1 and 3–5, the right hindlimb was immobilized. At the end of treatment, the femurs were removed and tested for bone porosity, bone mechanical properties, and cortical microarchitecture. Treatment with propranolol induced greater reductions in the bone porosity of the right femur and improved the mechanical properties of the femoral mid-shaft femur in comparison to the IMM control. Moreover, treatment with propranolol also improved the microarchitecture of cortical bones when compared with the IMM control, as indicated by scanning electron microscopy. The anti-osteoporotic property of propranolol was comparable with zoledronic acid and alfacalcidol. This study shows that the bone resorption induced by immobilization/disuse in rats can be suppressed by treatment with propranolol.

Muscle wasting in collagen-induced arthritis and disuse atrophy

The mechanisms of muscle wasting and decreased mobility have a major functional effect in rheumatoid arthritis, but they have been poorly studied. The objective of our study is to describe muscular involvement and the pathways in an experimental model of arthritis compared to the pathways in disuse atrophy. Female Wistar rats were separated into three groups: control (CO), collagen-induced arthritis (CIA), and immobilized (IM). Spontaneous locomotion and weight were evaluated weekly. The gastrocnemius muscle was evaluated by histology and immunoblotting to measure the expression of myostatin (a negative regulator), LC3 (autophagy), MuRF-1 (proteasome-mediated proteolysis), MyoD, and myogenin (satellite-cell activation). The significance level was set at P < 0.05, and histological analysis of joints confirmed the severity of the arthropathy. There was a significant difference in spontaneous locomotion in the CIA group. Animal body weight, gastrocnemius muscle weight, and relative muscle weight decreased 20%, 30%, and 20%, respectively, in the CIA rats. Inflammatory infiltration and swelling were present in the gastrocnemius muscles of the CIA rats. The mean cross-sectional area was reduced by 30% in the CIA group and by 60% in the IM group. The expressions of myostatin and LC3 between the groups were similar. There was increased expression of MuRF-1 in the IM (1.9-fold) and CIA (3.1-fold) groups and of myogenin in the muscles of the CIA animals (1.7-fold), while MyoD expression was decreased in the IM (20%) rats. This study demonstrated that the development of experimental arthritis is associated with decreased mobility, body weight, and muscle loss. Both IM and CIA animal models presented muscle atrophy, but while proteolysis and the regeneration pathways were activated in the CIA model, there was no activation of regeneration in the IM model. We can assume that muscle atrophy in experimental arthritis is associated with the disease itself and not simply with decreased mobility.

Immunomagnetic Separation and Impedance Measurement for Rapid Detection of Avian Influenza Virus

A method for specific and rapid detection of H5 subtype avian influenza virus was developed based on immunomagnetic separation coupled with impedance measurement.The biotin-labeled anti-H5 monoclonal antibodies were immobilized onto the streptavidin-coated magnetic nanobeads to separate and concentrate avian influenza virus H5N1.Impedance measurement was performed by the gold interdigitated array microelectrodes.Impedance magnitude increased with the increase of the concentration of H5N1 virus in the sample solution at the frequency of 100 kHz.The effects of antibody concentration,immunoreaction time and magnetic separation time were investigated and the optimized conditions were 0.25 g/L antibody,60 min immunoreaction time and 3 min magnetic separation time.A linear relationship between the logarithmic value of concentration of H5N1 virus and the value of impedance signal was found in pure virus sample with concentration range of 21-24 HA unit per 50 μL and in swab sample with concentration of 20-24 HA unit per 50 μL.The detection limits in pure virus sample and swab sample were 0.5 HA unit per 50 μL and 2 HA unit per 50 μL,respectively.

Selective Biocatalytic Acylation Studies on 5′-O-(4,4′-Dimethoxytrityl)-2′,3′-Secouridine: An Efficient Synthesis of UNA Monomer

Lipozyme® TL IM (Theremomyces lanuginosus lipase immobilized on silica) in toluene catalyzes the acylation of the 2 ′-OH over the 3 ′-OH group in 5 ′-O-(4,4 ′-dimethoxytrityl)-2 ′,3 ′-secouridine (5 ′-O-DMT-2 ′,3 ′-secouridine) in a highly selective fashion in moderate to almost quantitative yields. The turn over during benzoyl transfer reactions mediated by vinyl benzoate or benzoic anhydride was faster than in acyl transfer reactions with vinyl acetate or C1 to C5 acid anhydrides; except in the case of butanoic anhydride. The 2 ′-O-benzoyl-5 ′-O-DMT-2 ′,3 ′-secouridine obtained by Lipozyme® TL IM catalyzed benzoylation of 5 ′-O-DMT-2 ′,3 ′-secouridine was successfully converted into its 3 ′-O-phosphoramidite derivative in satisfactory yield, which is a building block for the preparation of oligonucleotides containing the uracil monomer of UNA (unlocked nucleic acid).

ChemInform Abstract: Biofilms and Their Engineered Counterparts: A New Generation of Immobilized Biocatalysts

AbstractReview: 41 refs.

147. In Vitro and In Vivo Delivery of Surface Immobilized AAV-2/9 to Arterial Cells

147. In Vitro and In Vivo Delivery of Surface Immobilized AAV-2/9 to Arterial Cells

Homologue expression of a fungal endo-1,4--D-xylanase using submerged and solid substrate fermentations

The xyn5 gene, which encodes an endo-β-1,4-xylanase (Xyn5), in Aspergillus nigerGS1 was cloned into an expression cassette under the control of constitutive glyceraldhehyde-3-phosphate dehydrogenase gene promoter. The expression system was designed to produce the recombinant enzyme containing a six-histidine peptide fused to the carboxyl end of the protein. The efficiency of Xyn5 production under submerged (SmF) and solid-state (SSF) fermentation was investigated using the homologous co-transformed A. niger AB4.1. A productivity of 17.1 U/(l·h) was estimated for SSF and 3.2 U/(l·h) for SmF calculated at peak value of enzyme titers. Recombinant Xyn5 obtained by SSF on polyurethane fiber, was purified 5.1-fold by anion exchange and immobilized metal affinity chromatography, with 35.7% recovery. The purified recombinant enzyme showed an apparent molecular weight of 30 kDa and optimal activity (522 U/mg protein) at pH 5.5 and 50°C. Key words: Aspergillus niger GS1, xylanolytic activity, solid-state fermentation, homologue expression, polyurethane fiber.

Optical resolution of n-butyl d- and l-lactates using immobilized lipase catalyst

n-Butyl D- and L-lactates (BuDLa and BuLLa) were incubated with immobilized lipase. (1)H-NMR showed that BuDLa reacted to oligomers, while BuLLa did not react. A mixture containing 90.4% of BuLLa and 9.6% of BuDLa was incubated with the enzyme for 72 h, then distilled. The purity of BuLLa increased to 98.6%.

Biocatalytic preparation of alkyl esters of citrus flavanone glucoside prunin in organic media

The biocatalytic preparation of alkyl esters of prunin, a flavanone glucoside derivative of citric flavonoid naringin, was performed in organic media using two commercial immobilized lipases: Novozym 435 ( Candida antarctica lipase B immobilized on an acrylic resin) and Lipozyme RM IM ( Rhizomucor miehei lipase immobilized on an anion exchange resin). The influence of several reaction parameters on the performance and regioselectivity of the biocatalytic process was investigated using four solvents (acetone, acetonitrile, tetrahydrofurane and t-butanol) and vinyl laurate as a donor. The biocatalytic modification of prunin was strongly dependant on the solvent, the molar ratio of the substrates, the enzyme and the chain length of the donor. The acylation was highly regioselective, obtaining 6″-O-acyl monoesters except when the donor was vinyl acetate in which case a diester seemed to be formed. Novozym 435 proved to be a more efficient biocatalyst than Lipozyme RM IM. In acetone and acetonitrile, derivatives with a 100% conversion yield were synthesized after only 6 h of reaction at 50 °C. The modified derivatives preserved the antiradical activity of the flavanone glucoside and their solubility notably increased in the hydrophobic medium 1-octanol.

Fluorescence Characterization of Immobilized Enzymes

not Available.

Immobilized imidazole and pyridine as coordinating ligands for ligninolytic peroxidase-like metalloporphines

Immobilized imidazole and pyridine as coordinating ligands for ligninolytic peroxidase-like metalloporphines

Fabrication and Characterization of Heteropolyacid Immobilized Membranes

not Available.

Liquid-phase oxidation of benzene and phenol on MCM-41 mesoporous molecular sieves modified with iron and cobalt compounds

Nanostructured (I) Fe2O3 and Co3O4 stabilized in the mesopores of an MCM-41 sieve and immobilized (II) FeCl2, Fe(acac)3, and FePc on the surface of an MCM-41 sieve functionalized with 3-aminopropyltriethoxysilane (3-APTES) were synthesized and examined. The materials were characterized by elemental analysis, H2 -TPR, X-ray diffraction analysis, IR and electronic absorption spectroscopy, as well as by low-temperature N2 adsorption. The catalytic activity was evaluated in the reaction of liquid-phase oxidation of benzene and phenol with hydrogen peroxide. Catalysts I showed a low activity in benzene oxidation, whereas catalysts II were active in the oxidation of phenol.