Static and Dynamic Studies of Gasoline in View of its Octane Number and its Toxic Effect

Gasoline come primarily from petroleum cuts, it is the preferred liquid fuel in our lives. Two gasoline samples of octane numbers 91 and 95 from Saudi Arabia petrol stations were studied. This study was achieved at three different temperatures 20oC, 30oC and 50oC representing the change in temperatures of the different seasons of the year. Both the evaporated gases of light aromatic hydrocarbons (BTEX) of gasoline samples inside the tank were subjected to analyze qualitatively and quantitatively via capillary gas chromatography. The detailed hydrocarbon composition and the octane number of the studied gasoline samples were determined using detailed hydrocarbon analyzer. The idea of research is indicating the impact of light aromatic compounds in gasoline on the toxic effect of human and environment on the one hand, and on octane number of gasoline on the other hand. Although the value of octane number will be reduced but this will have a positive impact on the environment as a way to produce clean fuel

Evaluation of the Antibiotic Resistance Pattern at the Medical Services Administration Hospital in Khartoum, Sudan, 2021

The number of antibiotics available is limited and does not cover the growing antibiotic resistance challenge. Misuse and overuse of antibiotics act as factors that help in improving and increasing the problem of resistance to those currently being prescribed by doctors. The study was carried out at the Medical Services Administration Hospital (MSAH) in Khartoum, Sudan to investigate the antibiotic resistance pattern for the period between Dec. 2020 and Jan. 2022. The results showed that, in a total of different clinical samples that were collected and processed, a total number of 980 organisms were isolated. The result indicated that 345 out of the total isolates (35.20%) were Klebsiella pneumonia, 326 (33.27%) Escherichia coli, 154 (15.71%) Pseudomonas aeruginosa, 130 (13.27%) Proteus mirabilis, and 25 (2.55%) Staphylococcus aureus. The results showed that K. pneumonia was quite resistant to piperacillin, cefuroxime, and azithromycin. The amikacin, imipenem, and meropenem antibiotics showed significant activity against K. pneumonia. The isolates of E. coli showed significant resistance to azithromycin and were more sensitive to imipenem and meropenem. P. aeruginosa was resistant to penicillin, amoxicillin/clavulanic acid, and azithromycin in a big way, but it was very sensitive to cefuroxime, the drug used to treat strep throat infections. P. mirabilis was found to be resistant to nalidixic acid, nitrofurantoin, amoxicillin/clavulanic acid, and azithromycin. It showed good sensitivity to amikacin, imipenem, and meropenem. It was clear that S. aureus was resistant to cefuroxime, ceftriaxone, nitrofurantoin, and norfloxacin, while tests showed that it was sensitive to imipenem

Biofunctional molecules from Citrullus colocynthis: An HPLC/MS analysis in correlation to antimicrobial and anticancer activities

Background: Citrullus colocynthis belongs to Family Cucurbitaceae. It grows widely in Egypt and Sudan and it has been used in folk medicine of Sudan and many other African countries as anti inflammatory, anti diabetic, and antioxidant agent. Objectives: To evaluate the antibacterial, antifungal, antiviral, anticancer activities of ethanolic crude extracts of the fruits, leaves, seeds and roots of this plant, as well as identifying them HPLC/MS. Materials and Methods: Dried fruits, seeds, leaves and roots of C. colocynthis were powdered and passed through a 40- mesh, then, the powders were extracted with 95% ethanol in a soxhlet apparatus. The residues were dried under reduced pressure in rotary evaporator. Crude extract from different plant parts were evaluated biologically and phytochemically. Results: All extracts showed good antifungal activities with inhibition zone ranges between 15.1 ± 0.32 to 25.6 ± 0.16 mm. In terms of plant organ, fruits were the most active. In term of fungal strain Aspergillus fumigatus and Geotricum candidum were the most sensitive. Against tested Gram +ve, all extracts showed good activities except roots, while antibacterial activity against Gram –ve showed that the fruits extract have good activity as it was the sole extract with activity against Pseudomonas aeruginosa. Test for antiviral activities showed moderate to weak inhibitions of cytopathic effect (CPE). Anticancer activities of different crude extracts showed that fruits had significant antitumor activities against all tested cell lines, the IC50 values were 24.6, 16, 18.5 and 19.7 µg /ml for HCT-116, MCF-7, Hep-G2 and Caco-2 respectively. Seeds extract was only active on HCT-116 and Hep G2 with IC50 =21.2 µg/ml for HCT-116 and 22.4 µg/ml for Hep G2. Leaves extract was only active against Hep G2 cancer cell line with IC50 19.7 µg/ml. Roots extract show weak antitumor activity on tested cell lines (IC50 values > 30µg/ml). HPLC/MS qualitative and quantitative analysis of different organs extracts revealed the presence of 21 compounds identified as fourteen cucurbitacins, three flavonoids, three tannins, and one sterol. The presence of cucurbitacins can explain most of the biological activities. Conclusion: The biological activities of colocynth different parts are due to the presence of secondary metabolites mainly cucurbitacins in addition to flavonoids and tannins.  These activities prove the use of this plant in folk medicine and deserve much more future exploration targeting their discovery in unexplored sources and their derivatives for improving their anticancer and antimicrobial abilities. Keywords: Citrullus colocynthis, crude extracts, antifungal, antibacterial, antiviral, anticancer, HPLC/M

The value of computed tomography-urography in predicting the postoperative outcome of antenatally diagnosed pelviureteric junction obstruction

Background The natural course of pelviureteric junction (PUJ) obstruction is  variable. Of those who require surgical intervention, there is no definite reliable  preoperative predictor of the likely postoperative outcome. We evaluated the value of preoperative computed tomography (CT)-urography in predicting the  postoperative outcome.Patients and methods Ten newborns with antenatally diagnosed PUJ obstruction  were evaluated after delivery with an abdominal ultrasound, and those with a renal pelvis measuring more than 3 cm in diameter were subjected to preoperative CT-urography. The kidney size, renal pelvis size, and renal parenchyma thickness were measured and documented. All underwent open surgical Anderson-Hynes dismembered pyeloplasty. The outcome was correlated to the preoperative renal parenchymal thickness as measured by means of preoperative CT-urography.Results Ten newborns (seven male and three female) with PUJ obstruction were  operated on. Their ages at surgery ranged from 8 days to 4 months (mean= 1.75 months). Eight had PUJ obstruction on the right side and two had PUJ obstruction on the left side. The mean renal pelvis size on the affected side was 4.9 cm (3.6–6.3 cm). The mean renal parenchymal thickness was 0.57cm (0.25–1.3 cm). Four patients had a renal parenchymal thickness less than 0.5 cm, and these patients showed poor results on followup isotope scan compared with those who had a renalparenchymal thickness of more than 0.5 cm [mean= 14.9% (12–19.6%)] compared with a mean of 44.2% (33–54%).Conclusion This is a preliminary report and the number of patients in our study is small to make definite conclusions, and further studies in this regard are important. We believe that renal parenchymal thickness as measured by means of preoperative CT-urography is an important predictor of the final outcome in patients with  antenatally diagnosed hydronephrosis. Those who had a renal parenchymal thickness of 0.5 cm or less showed poor results on followup isotope scan compared with those who had a renal parenchymal thickness of more than 0.5 cm.Keywords: outcome, pelviureteric junction obstruction, pyeloplast

Call Blocking Probabilities Reduction of Channel Assignment in Mobile Communication Systems

In wireless mobile communication systems, the radio spectrum is limited resource. However, efficient use of such limited spectrum becomes more important when the two, three or more cells in the network become hot - spot. The use of available channels has been shown to improve the system capacity. The role of channel assignment scheme is to allocate channels to cells in such way as to minimize call-blocking probability or call dropping probability and also maximize the quality of service. Different channel allocation schemes are in use for mobile communication systems, of which the Hybrid channel allocation (HCA) a combination of Fixed and Dynamic channel allocation schemes (FCA and DCA respectively) was effective. In this paper, the performance of three different channel allocation schemes FCA, DCA and HCA will be analytically compared and the results are presented

A prospective, randomized therapeutic trial for schistosomal specific nephropathy

A prospective, randomized therapeutic trial for schistosomal specific nephropathy. In this work 26 patients with schistosomal specific nephropathy were randomly distributed among three groups. Group I cases were given anti-schistosomal drugs (oxamniquine and praziquantel), group II cases were given anti-schistosomal drugs plus prednisolone, and group III cases were given anti-schistosomal drugs plus cyclosporine. The schistosomal specificity of kidney lesions was assessed by detecting the schistosomal specific antigens (CAA and CCA) and antibodies deposited in the renal glomeruli of these patients. Patients who had another etiologic cause which may explain their kidney disease were not admitted to this study. After initiation of the treatment, patients were followed up every other week in the outpatient clinic for 12 months. Follow-up showed complete remission of proteinuria in two cases in group II (duration of remission was 4 and 8 months) and in one case in group III (duration of remission was 6 months) but in none in group I. Partial remission was observed in one case in group I, in three cases in group II and in one case in group HI. During the observation period, improvement in kidney function was observed in two cases in group II but deterioration in kidney function was observed in one case in group I and in one other case in group III. We conclude that in patients with schistosomal nephropathy, none of the tried therapeutic regimens produce regression of the disease if given to patients with established disease

Comparative Study of Sensorless Control Methods of PMSM Drives

Recently, permanent magnet synchronous motors (PMSMs) are increasingly used in high performance variable speed drives of many industrial applications. This is because the PMSM has many features, like high efficiency, compactness, high torque to inertia ratio, rapid dynamic response, simple modeling and control, and maintenance-free operation. In most applications, the presence of such a position sensor presents several disadvantages, such as reduced reliability, susceptibility to noise, additional cost and weight and increased complexity of the drive system. For these reasons, the development of alternative indirect methods for speed and position control becomes an important research topic. Many advantages of sensorless control such as reduced hardware complexity, low cost, reduced size, cable elimination, increased noise immunity, increased reliability and decreased maintenance. The key problem in sensorless vector control of ac drives is the accurate dynamic estimation of the stator flux vector over a wide speed range using only terminal variables (currents and voltages). The difficulty comprises state estimation at very low speeds where the fundamental excitation is low and the observer performance tends to be poor. The reasons are the observer sensitivity to model parameter variations, unmodeled nonlinearities and disturbances, limited accuracy of acquisition signals, drifts, and dc offsets. Poor speed estimation at low speed is attributed to data acquisition errors, voltage distortion due the PWM inverter and stator resistance drop which degrading the performance of sensorless drive. Moreover, the noises of system and measurements are considered other main problems. This paper presents a comprehensive study of the different methods of speed and position estimations for sensorless PMSM drives. A deep insight of the advantages and disadvantages of each method is investigated. Furthermore, the difficulties faced sensorless PMSM drives at low speeds as well as the reasons are highly demonstrated. Keywords: permanent magnet, synchronous motor, sensorless control, speed estimation, position estimation, parameter adaptation

Acute vascular rejection after kidney transplantation outcome and effect of different therapeutic modalities

Background: Steroid resistant acute vascular rejection (AVR) is a great obstacle in successful renal transplantation (KTx). The aim of this work was to evaluate the outcome of histologically confirmed acute vascular rejection - which occurred in severe aggressive form in 39 patients following kidney transplantation as well as to study the outcome of therapy. These cases were chosen from 1000 renal allograft recipients who underwent kidney transplantation in the period between March, 1976 and April 1997 in Urology-Nephrology Center, Mansoura, Egypt.Methods: Statistical analysis of risk factors leading to AVR was carried out. The outcome of different rescue therapies used for AVR as well as graft survival functions were also analyzed.Results: Survival analysis for grafts with AVR revealed 60%, 53%, 30 %, 0% graft survival at 1, 2, 5, 10 yrs respectively after Tx. A statistically significant difference was found in comparison to patients who only experienced acute cellular rejection (90%, 84%, 71%, 46% graft survival at 1, 2, 5, 10 years post- KTx respectively) or patients who passed without rejection in their post-transplantation follow up (95%, 91.3%, 83.3%, 65.5% graft survival at 1, 2, 5, 10 yrs respectively). No statistically significant difference on the overall graft survival between the different modalities of therapy was noted. Steroid pulses + plasma exchange were given for 14 patients with AVR, whereas ATG, MAB ± plasma exchange were added to steroid resistant cases (25 patients). Logistic regression analysis of these data showed that prior blood transfusion, donor-recipient consanguinity, retransplantation are the most significant variables related to occurrence of AVR after kidney transplantation. At last follow up, 14 patients 35.9%) were living with functioning grafts, 16 patients (41%) were living on dialysis, 5 patients died with functioning grafts (12.8%) and 4 patients (10.25%) died with failed grafts.In conclusion: AVR remains a major obstacle for renal transplantation as it markedly impaired graft survival and responded poorly to therapy. Prior blood transfusion decreased the incidence of AVR whereas retransplantation and unrelated donation account significantly to the occurrence of AVR after renal Tx