323 research outputs found

    Aktivnost arginaze u ovarijskim strukturama krava švicarske smeđe pasmine i njezinih križanaca.

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    Arginase is the last enzyme of the urea cycle. It catalyses the hydrolysis of L-arginine to L-ornitine and urea. The aim of this study was to investigate the presence of arginase activity in ovarian structures such as: Graaf follicles, GF (Medium and Large size, M- and L-size), Corpus Haemorrhagicum (CH), and various types of Corpus Luteum (CL) such as: cyclic CL (CCL), 2-4 month pregnancy CL (2-4 MCL) and 4-7 month pregnancy CL (4-7 MCL). Ovarian tissues of 62 cows (7-10 years old and Brown Swiss or its cross-breeds), collected from a local slaughterhouse, were used as material. The materials were divided into 6 experimental groups, as follows: MGF group (n = 7), LGF group (n = 21), CH group (n = 7), CCL group (n = 6), 2-4 MCL group (n = 9) and 4-7 MCL group (n = 12). Arginase activities were measured as 0.056 ± 0.017, 0.100 ± 0.016, 2.517 ± 0.521, 0.827 ± 0.190, 0.674 ± 0.106 and 0.833 ± 0.093 U/mg protein in all groups, respectively. Arginase activity in the CH group was significantly higher than that in the CCL, 2-4 MCL and 4-7 MCL groups (P<0.001). The lowest enzyme activity was in the MGF and LGF groups. Hence, it was concluded that the arginase enzyme might play a crucial role in cell division, proliferation and differentiation in the ovarian tissues (especially the CH) of mature cows.Arginaza je posljednji enzim u ciklusu ureje koji katalizira hidrolizu L-arginina u L-ornitin i ureju. Cilj istraživanja bio je utvrditi prisutnost aktivnosti arginaze u ovarijskim strukturama kao što su Graafovi folikuli, GF (srednje veliki - M i veliki - L), corpus haemorrhagicum (CH) i različiti tipovi corpus luteum (CL) kao što su ciklični (CCL), 2-4 mjeseca graviditetni (2-4 MCL) i 4-7 mjeseci graviditetni (4-7 MCL). Tkiva ovarija od 62 krave (švicarske smeđe pasmine i križanaca u dobi od 7 do 10 godina) prikupljena su u lokalnoj klaonici. Materijali su bili podijeljeni u 6 pokusnih skupina kako slijedi: MGF skupina (n = 7), LGF skupina (n = 21), CH skupina (n = 7), CCL skupina (n = 6), 2-4 MCL skupina (n = 9) i 4-7 MCL skupina (n = 12). Slijedom navedenih skupina, aktivnost arginaze bila je 0,056 ± 0,017, 0,100 ± 0,016, 2,517 ± 0,521, 0,827 ± 0,190, 0,674 ± 0,106 i 0,833 ± 0,093 U/mg. Aktivnost arginaze u CH skupini bila je signifikantno viša u odnosu na skupine CCL, 2-4 MCL i 4-7 MCL (P<0,001). Najniža aktivnost enzima bila je u skupinama MGF i LGF. Zaključeno je o mogućoj ključnoj ulozi aktivnosti enzima arginaze u diobi stanica, proliferaciji i diferencijaciji ovarijskih tkiva (osobito CH) kod odraslih krava

    Demonstration of the histopathological and immunohistochemical effects of a novel hemostatic agent, ankaferd blood stopper, on vascular tissue in a rat aortic bleeding model

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    Background: Ankaferd Blood Stopper®(ABS) is a folkloric medicinal plant extract used as a hemostatic agent in traditional Turkish medicine. This experimental study investigated the histopathological and immunohistochemical effects of ABS on vascular tissue in a rat model of aortic bleeding.Methods: Four groups of 11 Wistar albino rats were used. The abdominal aortas of the rats were wounded; an ABS-soaked tampon was applied to rats in Groups 1 and 3, and a plain gauze tampon was applied to rats in Groups 2 and 4 until the bleeding stopped. The bleeding time was recorded. Immediately following sacrificing, the arteriotomy sites from Groups 1 and 2 were removed. The abdominal incisions in Groups 3 and 4 were closed following hemostasis. On Day 7 of the study, Group 3 and 4 rats were sacrificed and the abdominal aorta arteriotomy sites were removed for histopathological and immunohistochemical evaluation.Results: The mean bleeding time in 15 animals in Groups 2 and 4 was 4.9 ± 0.6 s, and in 22 animals in Groups 1 and 3 was 3.1 ± 0.6 s. Distal aortic occlusion was not observed on either Day 1 or 7 in any group. Significantly more widespread and dense endothelial nitric oxide synthase (eNOS) staining was observed in Group 1 animals than Group 2. On Days 1 and 7 after application of ABS, histopathological changes, consisting of necrosis, inflammation, and endothelial cell loss, in the rat abdominal aortas did not differ between Groups 1 and 2. The basophilic discoloration in the ABS group on the operation day was a result of a foreign body reaction and hemosiderin-loaded histiocyte accumulation, which occurred on Day 7.Conclusions: In this study, hemostasis was successfully achieved with ABS in rat abdominal aortas. No histopathological change was found in the rat abdominal aortas between the ABS and control groups on Days 1 and 7. Further studies on the long-term effects of foreign body reactions and hemosiderin-loaded histiocyte accumulation are required. © 2010 Kandemir et al; licensee BioMed Central Ltd

    Intrinsic Spin-Orbit Interaction in Graphene

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    In graphene, we report the first theoretical demonstration of how the intrinsic spin orbit interaction can be deduced from the theory and how it can be controlled by tuning a uniform magnetic field, and/or by changing the strength of a long range Coulomb like impurity (adatom), as well as gap parameter. In the impurity context, we find that intrinsic spin-orbit interaction energy may be enhanced by increasing the strength of magnetic field and/or by decreasing the band gap mass term. Additionally, it may be strongly enhanced by increasing the impurity strength. Furthermore, from the proposal of Kane and Mele [Phys. Rev. Lett. 95, 226801 (2005)], it was discussed that the pristine graphene has a quantized spin Hall effect regime where the Rashba type spin orbit interaction term is smaller than that of intrinsic one. Our analysis suggest the nonexistence of such a regime in the ground state of flat graphene

    Optimizing the use of pressurized bladders for the assembly of HL-LHC MQXFB magnets

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    The use of pressurized bladders for stress control of superconducting magnets was firstly proposed at Lawrence Berkeley National Laboratory (LBNL) in the early 2000s. Since then, the so-called bladders and keys procedure has become one of the reference techniques for the assembly of high-field accelerator magnets and demonstrators. Exploiting the advantages of this method is today of critical importance for Nb3Sn-based accelerator magnets, whose production requires the preservation of tight stress targets in the superconducting coils to limit the effects of the strain sensitivity and brittleness of the conductor. The present manuscript reports on the results of an experimental campaign focused on the optimization of the bladders and keys assembly process in the MQXFB quadrupoles. These 7.2 m long magnets shall be among the first Nb3Sn cryomagnets to be installed in a particle accelerator as a part of the High Luminosity upgrade of the LHC. One of the main practical implications of the bladders technique, especially important when applied to long magnets like MQXFB, is that to insert the loading keys, the opening of a certain clearance in the support structure is required. The procedure used so far for MQXF magnets involved an overstress in the coils during bladder inflation. The work presented here shows that such an overshoot can be eliminated thanks to additional bladders properly positioned in the structure. This optimized method was validated in a short model magnet and in a full-length mechanical model, becoming the new baseline for the series production at CERN. Furthermore, the results are supported by numerical predictions using Finite Element models

    Preventing seismic pounding of adjacent structures using viscous wall damper device

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    Today, a number of researchers are broadly studying the effective implementation of supplemental seismic energy dissipation systems to improve seismic behavior of structures during earthquakes. The current article studies the impacts of employing Viscous Wall Damper devices to couple two adjacent structures on seismic response of the new system. An exclusive finite element algorithm capable of modeling and analyzing structures equipped with special damper systems was used in order to perform a nonlinear time history analysis subjected to seismic excitation. Two ten-story RC framed structures are modeled adjacently in 11 different cases, each representing existence or damping coefficient of the Viscous Wall Damper device. A parametric study has been conducted in each case to assess the effectiveness of implementing Viscous Wall Damper devices on improving seismic behavior of the coupled structure. The considered metrics include rotation and displacement amplitude, plastic hinge formation, and induced element forces. It has been proved that the proposed damper system substantially diminishes and dissipates induced seismic response of the system. Also, it is indicated that the extent to which Viscous Wall Damper device contributes in mitigating seismic responses is highly correlated with the damping coefficient

    Levels of selected minerals, nitric oxide, and vitamins in aborted Sakis sheep raised under semitropical conditions

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    The serum levels of calcium, phosphorus, magnesium, copper, zinc and iron and of nitric oxide, retinol, and β-carotene were determined in Sakiz ewes that had experienced an abortion and in healthy controls. Ten healthy and 25 aborted Sakiz sheep were selected from Afyon zone in western Turkey. Their ages ranged between 2 and 4 years weighing between 40 and 60 kg at the time of experiment. All of the abortions occurred in October. The concentrations of retinol, β-carotene, phosphorus, and zinc were significantly lower and those of calcium and nitric oxide were increased in aborted ewes relative to healthy controls. The serum levels of iron, copper, and magnesium were not significantly different among the two groups. In conclusion, abortion is an important problem in commercially important species of ruminants in many regions in the tropics including of western Turkey. Deficiencies of retinol, β-carotene, phosphorus and zinc, and the increase of calcium and nitric oxide concentration may play an important role in the etiology of abortion in ewes. Prophylactic measures such as vitamin and mineral supplementation may be of help to prevent or reduce the incidence of abortion in sheep
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