130 research outputs found
Evaluation of acute toxicity and anti-inflammatory effects of Baccharoides schimperi (DC.) in experimental animals
Background: Steroidal and non-steroidal anti-inflammatory drugs are most commonly used to treat inflammation, and shown to have severe side effects. In this study, we aimed at evaluating the anti-inflammatory and acute toxicity effects of Baccharoides schimperi (DC.) in order to get new anti-inflammatory agents of natural origin.Materials and methods: The aerial part of the plant was dried under shade, ground and extracted with 96% alcohol (BSE). It was further fractionated in sequence to n-hexane (BSH), chloroform (BSC) and methanol (BSM) soluble fractions. Acute toxicity was evaluated by oral administration of plant and hind paw induced-edema method in rats was used for the anti-inflammatory evaluation.Results: The BSE was found safe up to the dose level of 3 g/kg b.w. and showed LD50 value 7.250 g/kg body weight (b.w.) in mice. BSE showed significant anti-inflammatory effect (62.91%) at 500 mg/kg b.w. Further the n-hexane, chloroform and methanol fractions of BSE were tested for antiinflammatory activity. The n-hexane fraction (BSH) exhibits significant activity (64.87%) at 400 mg/kg b.w. The methanol fraction (BSM) showed dose dependent activity, highest activity (60.42%) was observed at higher dose 400 of mg/kg b.w. In chloroform fraction (BSC) no significant activitywas observed.Conclusion: The results of the study revealed that the plant is safe to the experimental model and recommended as a potential source of antiinflammatory agent.Key words: Acute toxicity, anti-inflammatory activity, Baccharoide schimperi (DC.
EVALUATION OF ACUTE TOXICITY AND ANTI-INFLAMMATORY EFFECTS OF BACCHAROIDES SCHIMPERI (DC.) IN EXPERIMENTAL ANIMALS
Background: Steroidal and non-steroidal anti-inflammatory drugs are most commonly used to treat inflammation, and shown to have severe side effects. In this study, we aimed at evaluating the anti-inflammatory and acute toxicity effects of Baccharoides schimperi (DC.) in order to get new anti-inflammatory agents of natural origin.
Materials and methods: The aerial part of the plant was dried under shade, ground and extracted with 96% alcohol (BSE). It was further fractionated in sequence to n-hexane (BSH), chloroform (BSC) and methanol (BSM) soluble fractions.
Acute toxicity was evaluated by oral administration of plant and hind paw induced-edema method in rats was used for the anti-inflammatory evaluation.
Results: The BSE was found safe up to the dose level of 3 g/kg b.w. and showed LD50 value 7.250 g/kg body weight (b.w.) in mice. BSE showed significant anti-inflammatory effect (62.91%) at 500 mg/kg b.w. Further the n-hexane, chloroform and methanol fractions of BSE were tested for anti-inflammatory activity. The n-hexane fraction (BSH) exhibits significant activity (64.87%) at 400 mg/kg b.w. The methanol fraction (BSM) showed dose dependent activity, highest activity (60.42%) was observed at higher dose 400 of mg/kg b.w. In chloroform fraction (BSC) no significant activity was observed.
Conclusion: The results of the study revealed that the plant is safe to the experimental model and recommended as a potential source of anti-inflammatory agent
Mushroom-Like EBG to Improve Patch Antenna Performance For C-Band Satellite Application
In order to suppress the surface waves excitation that are caused by thick substrate in a patch antenna, a mushroom-like EBG (Electromagnetic Band Gap) structure is used. Such structures enhance its characteristics of gain, directivity, bandwidth and efficiency. Firstly, we determined frequency band gap characteristics of mushroom like EBG unit cell value by using CST software with 3mm (0.06λo) for covering 6 GHz. The periodic arrangement of such mushroom-like EBG structures was not limited by any interconnecting microstrip lines. Four columns of EBGs shifted inwards to antenna edges by 0.3mm (0.06λo) or a gap of its design around the patch from the left and right sides. Different configurations were also examined in order to get the better improvement in antenna performance. The final design of this mushroom-like shifted periodic structure shows an effective increase in the directivity by 77%, gain by 108%, bandwidth by 29% and the efficiency by 20% for the antenna. This structure has diversified application possibility for wireless and satellite communications
Serine Protease Variants Encoded by Echis ocellatus Venom Gland cDNA: Cloning and Sequencing Analysis
Envenoming by Echis saw-scaled viper is the leading cause of death and morbidity in Africa due to snake bite. Despite its medical importance, there have been few investigations into the toxin composition of the venom of this viper. Here, we report the cloning of cDNA sequences encoding four groups or isoforms of the haemostasis-disruptive Serine protease proteins (SPs) from the venom glands of Echis ocellatus. All these SP sequences encoded the cysteine residues scaffold that form the 6-disulphide bonds responsible for the characteristic tertiary structure of venom serine proteases. All the Echis ocellatus EoSP groups showed varying degrees of sequence similarity to published viper venom SPs. However, these groups also showed marked intercluster sequence conservation across them which were significantly different from that of previously published viper SPs. Because viper venom SPs exhibit a high degree of sequence similarity and yet exert profoundly different effects on the mammalian haemostatic system, no attempt was made to assign functionality to the new Echis ocellatus EoSPs on the basis of sequence alone. The extraordinary level of interspecific and intergeneric sequence conservation exhibited by the Echis ocellatus EoSPs and analogous serine proteases from other viper species leads us to speculate that antibodies to representative molecules should neutralise (that we will exploit, by epidermal DNA immunization) the biological function of this important group of venom toxins in vipers that are distributed throughout Africa, the Middle East, and the Indian subcontinent
Enhancement of boresight radiation for leaky wave antenna array
An array of half-width microstrip leaky-wave antennas (HW-MLWAs) of two uniform elements was designed to obtain maximum boresight radiation. Achieve this, two uniform of HW-MLWAs are placed at 180◦ and fed by a probe located at the center between the elements, two uniforms of HW-MLWAs, loaded terminated by 50Ω lumped element. Two beams from two branches individual merge to form the resultant directive beam. The simulation represents the susceptibility of the proposed array of uniform HW-MLWAs to the radiation broadside direction effectively. The predict bandwidth matched of the array is 582 MHz (4.18–4.76 GHz). The direction of its main beam in boresight happens over a wide 13%, relatively (4.18-4.76 GHz) band. The proposed peak gain at the boresight direction of the array is 9.91 dBi
Novel design of triple-bands EBG
This paper presents a novel design for a triple band electromagnetic band gap (EBG) structures that provides three band gaps, with operating frequency of below 10 GHz, while the ordinary mushroom like EBG structure gives only one band gap. Complexity reduction (reduce the number of unit cells and Vias) was achieved by replacing each four cells of the Mushroom like EBG by the one of double slotted type EBG (DSTEBG) or triple side slotted EBG (TSSEBG). The Mushroom like EBG was further modified by increasing its size and inserting the slots to gain more capacitance and inductance which resulted into triple band stop.The new designs wer compared with bandwidths expressed by other EBGs and -20 dB cut-off frequencies. The size of EBG element and the gap between EBG elements, and slot width were investigated to analyse their effect on the transmission response. The structures were designed from 2.54 mm Rogers RT/Duroid 6010 substrate with relative permittivity of 10.2 and loss tangent of 0.0023. Among the investigated EBGs, the single band mushroom like EBG and the triple band of the TSSEBG demonstrated better bandwidth and lower resonance frequency performance, whereas the DSTEBG showed larger bandwidth for the first and third band. The proposed EBGs could be useful in the antenna design and other microwave circuits
Electronically controlled radiation pattern leaky wave antenna array for (C band) application
This paper provides an insight of a new, leaky-wave antenna (LWA) array. It holds the ability to digitally steer its beam at a fixed frequency by utilizing only two state of bias voltage. This is done with acceptable impedance matching while scanning and very little gain variation. Investigation is carried out on LWAs’ control radiation pattern in steps at a fixed frequency via PIN diodes switches. This study also presents a novel half-width microstrip LWA (HWMLWA) array. The antenna is made up of the following basic structures: two elements and reconfigurable control cell with each being comprised of two diodes and two triangle patches. A double gap capacitor in each unit cell is independently disconnected or connected via PIN diode switch to achieve fixed-frequency control radiation pattern. The reactance profile at the microstrip’s free edge and thus the main beam direction is changed once the control-cell states are changed. The main beam may be directed by the antenna between 61o and 19o at 4.2 GHz. C band achieved the measured peak gain of the antenna of 15 dBi at 4.2 GHz beam scanning range
Side lobe reduction in array antenna by using novel design of EBG
A novel design of EBG is used to replace the mushroom like EBG for surrounding the array patch antenna. In order to improve its radiation performances, Electromagnetic band stop for reducing the surface waves effects is presented. The novel design of Triple Side Slotted EBG (TSSEBG) showed an improvement in the antenna efficiency, directivity and gain as compared to the reference antenna without using EBG, due to reduce the surface waves effects which leads to decrease the side lobes. TSSEBG has been introduced by some modifications in conventional mushroom-like EBG structure. Reducing the complexity was achieved by reducing the number of unit cells and vias, in case of used TSSEBG instead of mushroom like EBG. Additionally, the TSSEBG provided triple band gap compared with mushroom like EBG structure which had only one band gap frequency at 6 GHz. The placement of TSSEBG is a flexible structure which provides a good choice in the antenna applications. The simulation results of array patch antenna with and without mushroom like EBG and TSSEBG are arranged in Table 1. This structure has vast applications in satellite communications
Trends of Coagulation Parameters in Human Immunodeficiency Virus Patients
Background and Objectives: HIV disease is recognized to cause inconsistencies in coagulation via various pathways during infection. Some studies have indicated that HIV-infected patients are prone to developing thrombocytopenia, thrombosis, or autoantibodies that may cause difficulties in diagnosis. This study is intended to measure the trend of coagulation parameters in Sudanese patients with HIV. Materials and Methods: A cross-sectional study was carried out in patients with HIV admitted to the Sudan National AIDS Program (SNAP) from January 2018 to December 2019. Prothrombin time (PT), partial thromboplastin time (PTT), thrombin time (TT), D-dimer (DD), hemoglobin (HB), total lymphocyte count (TLC), platelet count (PLT), and a disintegrin and metalloproteinase with thrombospondin type 1 motif, member 13 (ADAMTS13), were evaluated among HIV Sudanese patients. Results: Out of the 44 HIV patients included, 6 (13.6%) were found to have thrombotic thrombocytopenic purpura-like events and 12 (27.2%) had antiphospholipid antibodies, of whom 8 (66.6%) showed anticardiolipin antibody (1gG (75%) and IgM (25%)) and 4 showed lupus anticoagulants. The HB, TLC, and PLT values were found to be significantly lower in HIV patients than in control (p = 0.000, 0.000, and 0.050, respectively). The PT and ADAMTS13 values showed no significant difference between HIV patients and control (p = 0.613 and 0.266, respectively). The PTT, TT, and DD values were found to be augmented in HIV patients versus the control (p = 0.000). Conclusions: Thrombotic thrombocytopenic purpura-like events among HIV Sudanese patients were explored. In addition, antiphospholipid antibodies were strikingly seen in these patients. Additional research is anticipated to confirm these diagnoses
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