3,910 research outputs found

    Preliminary toxicological evaluations of Polypeptide-K isolated from Momordica Charantia in laboratory rats.

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    This study examined the toxicological effects and safety of polypeptide k isolated from the seeds of Momordica charantia in laboratory rats. 30 male Sprague Dawley rats (12 weeks old, bodyweight 180-200 g) were randomly divided into 3 groups (1000 mg/kg, 500 mg and 0 mg/kg). Rats were acclimatized to laboratory conditions for 7 days and at day 8 rats were dosed orally with polypeptide k (in 2% DMSO/normal saline) and the controls received the dosed vehicle only. Rats were then observed for 72 hours before sacrificed. Rats were anaesthetized by pentobarbital (50 mg/kg ip) and 2-3.0 mL of blood was taken by cardiac puncture and rats were scarified by anaesthetic overdose. Immediately, organs (heart, lungs, liver, kidneys) were weigh and taken for histology. Organ sections were then evaluated by a histopathologist. Serum samples were assayed for liver functions (ALT and γ-GT) and kidney functions (BUN and creatinine). All rats showed normal behavior after the dosing and no statistical changes were observed in al blood parameters and organ weight. Histological examinations revealed normal organ structures. In conclusion, dosing of rats up to 1000 mg/kg did not have any effects on the rat behavior, liver or kidney functions nor histology of the selected organs

    Compact microstrip bandpass filter with sharp passband skirts using square spiral resonators and embedded-resonators

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    The aim of this paper is to produce and develop a new four-pole microstrip bandpass filter (BPF) structure for high selectivity applications. The microstrip BPF is designed using Chebychev lowpass prototype with passband ripple of 0.05 dB and bandwidth of 120 MHz, which operates at center frequency of 2.3 GHz. This filter is designed by using square spiral resonator structures and embedded-resonator topology with the same fundamental frequency to make it more compact; furthermore, it has high quality performance in terms of the frequency responses. The size of the compact microstrip filter is 24.74 × 21.20 mm2. The proposed filter was designed, fabricated and tested. The measured results show that the minimum passband insertion loss is 2.65 dB, while the measured return loss is better than -11 dB in the passband. Very good agreement between the simulated and measured results was observed

    Bio-based liquid fuels as a source of renewable energy: A review

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    Limited availability of fossil fuels and their associated environmental impact during combustion remains the primary basis for exploring alternative energy sources such as bio-based liquid fuels. Several feedstocks have been used to produce biofuels for different applications with their own pros and cons. For instance, production of bio-fuels using human food chain raw materials such as corn, soy, peanut, and sugarcane are receiving increased criticism due to the competing demands of the same sources for human consumption as food. However, the non-food biomass in the form of agricultural wastes, municipal wastes, waste vegetable oil, and microbial sources are abundantly available that can be utilized as feedstock for production of biofuels. Because of this reason, most biofuels have been produced using the feedstocks that do not affect the food chain. Thus, in this work, the feedstocks of different generation biofuels and their potential yield and associated greenhouse gas emissions, production technologies are critically surveyed. Moreover, the application of biofuels for different purposes are analyzed and compared with their corresponding conventional fuels. The survey also points out the recent issues and challenges of biofuels with their resolution. The future research directions are suggested to sustain biofuel production

    Recent trends in biodiesel production from commonly used animal fats

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    Changes in climate due to the enormous amount of carbon dioxide emissions have really encouraged the development of energy sources that are renewable, sustainable, and eco-friendly. The development of alternative energy sources can also be attributed to the rapid decrease in resources of fossil energy. Biodiesel has gained significant interest in recent years due to its fossil fuel–like properties and sustainable and eco-friendly characteristics. However, most biodiesels are expensive because of the high cost of feedstock largely based on edible vegetable oil sources. The use of animal fats waste as cost effective feedstock in biodiesel production has gained considerable attention in recent years. Although, most studies regarding the use of animal wastes as feedstock in biodiesel production are still in the early stages, the advantages of this type of feedstock have been highlighted in the literature. However, most studies have not focus on the recent advances in the use of animal fats waste. The studies on the use of novel approach have been reported in isolation. Therefore, this current study attempts to highlight recent developments of the most commonly used animal fats waste in the production of biodiesel. In addition, emphasis was given to the most appropriate production technique, catalyst, energy requirement, and optimum reaction conditions

    Naso-Maxillary extramedullary plasmacytoma: A case report

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    We report an early case of extramedullary, right maxillary sinus and nasal, plasmacytoma. The patient was a 27 years old female who presented with nasal bleeding and a nasal mass. Imaging studies showed opacities in the nasal cavity and the maxillary sinus but there was no bone involvement.  A biopsy from the nasal mass showed a plasmacytoma. She was investigated to rule out systemic disease. The investigations included; serum electrophoresis, urine analysis for Bence Jones proteins, bone marrow aspirates study and radiological skeletal survey. The results of all investigations were negative. After complete excision of the tumour endoscopically the patient was treated with adjuvant radiotherapy. She remained well, without recurrence or spread of the tumour at 4 years follow up. CTscans pre and postoperatively as well as H&E and Immunohistochemistry slides are presented. To our knowledge, this is the first case to be reported in Sudan.                                                                   &nbsp

    U-shaped inductively coupled feed RFID tag antenna for gain enhancement

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    An inductively coupled feed novel technique is proposed to enhance the performance of RFID tag antennas. The applied feeding concept comprises of two opposing symmetrical U-shaped structures to feed a radiating body. It is a simple alternative to effectively match between the antenna impedance with the chip impedance from the flexible augmentation of equivalent inductance to the radiating body. The proposed feeding method offers better expectation of performance among antenna size, impedance, and gain at the size of 50 × 70 × 1.6 mm3. The peak gain of the proposed tag antenna is 2.5 dBi at its operating frequency, which is higher among conventional tag antennas. Measured results indicate that this tag antenna has a good impedance matching characteristic at 904-937 MHz (power reflection coefficient better than -3 dB). The comparison between the simulation and measurement results verified the proposed technique capability to improve overall performance of the tag antennas

    Embedded 3D Printing of Novel Bespoke Soft Dosage Form Concept for Pediatrics

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    Embedded three-dimensional printing (e-3DP) is an emerging method for additive manufacturing where semi-solid materials are extruded within a solidifying liquid matrix. Here, we present the first example of employing e-3DP in the pharmaceutical field and demonstrate the fabrication of bespoke chewable dosage forms with dual drug loading for potential use in pediatrics. LegoTM-like chewable bricks made of edible soft material (gelatin-based matrix) were produced by directly extruding novel printing patterns of model drug ink (embedded phase) into a liquid gelatin-based matrix (embedding phase) at an elevated temperature (70 °C) to then solidify at room temperature. Dose titration of the two model drugs (paracetamol and ibuprofen) was possible by using specially designed printing patterns of the embedded phase to produce varying doses. A linearity [R2 = 0.9804 (paracetamol) and 0.9976 (ibuprofen)] was achieved between percentage of completion of printing patterns and achieved doses using a multi-step method. The impact of embedded phase rheological behavior, the printing speed and the needle size of the embedded phase were examined. Owning to their appearance, modular nature, ease of personalizing dose and geometry, and tailoring and potential inclusion of various materials, this new dosage form concept holds a substantial promise for novel dosage forms in pediatrics

    Development of new all-optical signal regeneration technique

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    All-optical signal regeneration have been the active research area since last decade due to evolution of nonlinear optical signal processing. Existing all-optical signal regeneration techniques are agitated in producing low Bit Error Rate (BER) of 10-10 at below than -10 dBm power received. In this paper, a new all-optical signal regeneration technique is developed by using phase sensitive amplification and designed optical phase locked signal mechanism. The developed all-optical signal regeneration technique is tested for different 10 Gb/s Differential Phase Shift Keying degraded signals. It is determined that the designed all-optical signal regeneration technique is able to provide signal regeneration with noise mitigation for degraded signals. It is analyzed that overall, for all degraded test signals, average BER of 10-13 is achieved at received power of -14 dBm. The designed technique will be helpful to enhance the performance of existing signal regeneration systems in the presence of severe noise by providing minimum BER at low received power

    Investigation of the stability of cerium oxide in diesel fuel for nano-enhanced fuel formulation

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    Abstract. Enhancing fuels through nano-addition has become a prospect in keeping both renewable and non-renewable fuels as energy sources for the transportation sector. One of the challenges when using nanofluids in a specific system is the fluid’s ability to be stable for a longer period. Undesired settlement of nanoparticles can cause damage to the system operating within its limits due to contamination, therefore stability study has paramount importance in the nano-enhanced fuel introduction in internal combustion engines. checking nanofluid stabilization consider a challenge since it takes time and it has tendency to aggregate in certain time, therefore UV vis device was a perfect tool to investigate the stability of the nano fuel. Three-step method using UV-Vis spectral absorbency device was selected to measure the nanofluid and ensure the stability of the solution daily. Cerium oxides consider one of the challenging nano additives to blend with fuel. To measure its stability, it was observed that when the nanofluid fuel was mixed with nanoparticles in quantities estimated at 25, 50, and 75 ppm, the nano fuel solution showed a high stability capacity in the first days, which indicate revealed that blending at high speeds followed by ultrasonication in an ultrasonic homogenizer for 40 minutes increases the stability of the mixes. The nano fluid fuel was gradually decreasing during the next following 8 days, but all of the blended fuel remains stable for percentage above 80 percent that UV-Vis 3 step method is trustable for investigating the stability of the nano enhanced fuel
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