Aim: Assess performance of broth microdilution (BMD) as well as agar dilution methods for antimicrobial susceptibility testing of Staphylococci using tetrazolium salt. Methods and Results: Minimum inhibitory concentration (MIC) of eight antimicrobials; vancomycin (VA), linezolid, oxacillin, gentamicin (CN), tetracycline, ciprofloxacin, erythromycin and clindamycin was investigated for 80 isolates of Staphylococci by BMD with the addition of dimethyl thiazole diphenyl tetrazolium bromide (MTT), agar dilution with the addition of MTT and triphenyl tetrazolium chloride at the standard bacterial concentration together with addition of MTT at an experimental bacterial concentration. BMD (MTT) showed the highest agreement in comparison with the standard BMD. Conclusions: Colorimetric BMD was rapid and easy to interpret. Colorimetric agar dilution (MTT) was less tedious than BMD. Significance and Impact of the Study: Colorimetric antibiotic susceptibility is a good option to provide rapid reliable results for critically ill patients. In addition, agar dilution (MTT) helps to investigate outbreaks of methicillinresistant Staphylococcus aureus (MRSA), VISA or VRSA. BMD (MTT) can be performed routinely to detect VA MIC in MRSA blood stream infections and hospital acquired pneumonia, where, high VA MIC is associated with a higher mortality rate.

During the past few years, high-strength concrete (HSC) has been increased interest amongst civil and structural engineers. On the Other hand, several varieties of fiberreinforced concretes are now utilized in the building sector for a variety of purposes. This paper discusses the influence of using steel fiber on the compressive strength and splitting strength of high strength concrete with Nano-silica (NS) and/or silica fume (SF). The experimental effort consists of casting and testing 16 distinct mixes. All of the mixes have the same cement content, and some have the same water content and aggregate content, but they differ in factors such as the quantity of NS, SF, and steel fiber. The mixes have been categorized into three main groups. In group one, the impact of adding 3% SF and/or 2% NS was investigated. In group two, the effect of adding 10% SF and the sources of type F admixtures was studied. In group three, two subgroups to study the effect of adding 5% SF, as well as the effect of w/c ratio were considered. As a results, it is established that the average compressive strength of mixes containing fibers to the compressive strength of samples without fibers at 7, 28 and 56 days is 1.04, 1.0 and 1.12, respectively. The average ratio of splitting strength to compressive strength at 28 days is around 7.22%.

Background: Laparoscopic cholecystectomy is the gold standard treatment for symptomatic gallstones. Conversion to an open procedure is necessary in 5-10% of patients.The aim of work: The present study was to illustrate the incidence of conversion of laparoscopic cholecystectomy to open cholecystectomy & to validate the efficacy of "CLOC" (Conversion from Laparoscopic to open cholecystectomy) risk scoring system on the patients included in the study.Patients and methods: The present observational prospective study was conducted in EL-Demerdash Teaching Hospital (January 2019-January 2020). The study included (100) symptomatic cholelithiasis patients. Patients were divided into two groups, firstly those who completed laparoscopic cholecystectomy and secondly those who were converted into open cholecystectomy. Preoperative variables included patient demographics, indications for surgery, ASA grade, admission type, ultrasound findings and preoperative endoscopic retrograde cholangiopancreatography (ERCP). Validation of the "CLOC" scoring system was applied to all patients. Operative data were gathered prospectively, and the difficulty of the procedure was graded using the Nassar scale (grades 1-4).Results: (24%) of patients recorded difficult total score; open surgery was conducted in (5%). There was statistically significant relation between CLOC risk scoring level and age (p<0.001); indication (p=0.002); ASA (p=0.002); gallbladder wall thickness. (p<0.001) and preoperative ERCP patients (p=0.003). There was statistically significant increase in difficulty in male compared to female. (p=0.019). There was actual conversion according to groups with 'high risk scoring >7 and conversions in the' low risk >6 easy' group below. (p=0.042); highly statistically significant increase of mean in difficult group compared to essay group (p<0.001). The difficult group complications rate was higher than the easy group (75% versus 10.5%); gallbladder rupture was mostly reported in (37.5% and 2.6%) of difficult group and easy group cases, respectively. Receiver operating characteristics (ROC) curve sensitivity was 92%; specificity was 98.7%. Age, gender, indication, ASA, gallbladder wall and Pre-Operative ERCP have a significant effect on the difficulty. Conclusion:The present study could conclude that parameters as older age, male gender, cholecystitis, ASA, thick wall GB, preoperative ERCP are predictors for difficult LC. Meanwhile these