90 research outputs found

    Rheology Of Cement Paste Containning Chemical Admixtures

    Get PDF
    Understanding the Rheology of cement and water is a not a simple task since, thebehaviour of complicated system varies with time and there is still a great deal of work to bedone before, it is properly understood. In this study, we used a new simple and cheaptechnique to evaluate flow properties of cement paste .This technique is based on dropping aneedle from a constant height. The penetration depth is measured at different circumstances,different w/c ratios, different types of super plasticizer, and different percentage of admixturefor two types of cement types of cements OPC type V (CEMEX) and OPC type I (HELWAN)were considered in this study. Also, effect of retempering on penetration depth were alsoconsidered. Finally effect of variation of needle drop height was also considered. Thepenetration depth technique proved to be effective in monitoring the effect ofsuperplasticizer/cement ratio percentage, effect of time, manual remixing after 30 minutesand needle drop height on the rheological behavior of different types of cement paste, whichfurther proves the effectiveness of this method in evaluation of cement paste Rheology

    Encapsulation of Essential Oils and Their Use in Food Applications

    Get PDF
    Due to the modern lifestyle and consumers’ interests, demands toward healthy foods and nutraceuticals were increased, among them essential oils (EOs) characterized by different biological activities. However, the use of EOs in foods and pharmaceuticals may be limited due to the hydrophobicity nature in addition to the instability and cause of degradation upon exposure to environmental conditions, e.g., oxygen, temperature, and light. Therefore, encapsulation in various colloidal systems such as microcapsules, nanospheres, nanoemulsions, liposomes, and molecular inclusion complexes, seem to be the solution for such issues. New trends in food packaging have also been focused on exploiting capsulated bioactive EOs constituents for extending foods’ shelf life due to their potent antimicrobial agents and the great activity against pathological bacteria. Micro and nanoencapsulation of EOs may affect their biological activities based on the technique used. In the current chapter, different subjects have been discussed, like techniques used for the encapsulation of EOs, potential applications in food, and their behaviors/trends after encapsulation

    Clinical and Radiographic Predictors of Successful Coronary Angiography Through Right Radial Artery Access

    Get PDF
    Background: One of the limitations of the right radial access approach is complex vessel anatomy, such as subclavian tortuosity. Several clinical predictors have been proposed for tortuosities, such as older age, female sex and hypertension. In this study, we hypothesised that chest radiography would add predictive value to the traditional predictors. Methods: This prospective blinded study included patients who underwent transradial access coronary angiography. They were classified into four groups according to difficulty: Group I, Group II, Group III and Group IV. Different groups were compared according to clinical and radiographic characteristics. Results: The study included 108 patients (54, 27, 17 and 10 patients in Groups I, II, III and IV, respectively). The rate of crossover to transfemoral access was 9.26%. Age, hypertension and female sex were associated with a greater difficulty and failure rates. Regarding radiographic parameters, a higher failure rate was associated with a higher diameter of the aortic knuckle (Group IV, 4.09 ± 1.32 cm versus Groups I, II and III combined, 3.26 ± 0.98 cm; p=0.015) and the width of the mediastinum (Group IV, 8.96 ± 2.88 cm versus Groups I, II and III combined, 7.28 ± 1.78 cm; p=0.009). The cut-off value for prominent aortic knuckle was 3.55 cm (sensitivity 70% and specificity 67.35%) and the width of mediastinum was 6.59 cm (sensitivity 90% and specificity 42.86%). Conclusion: Radiographic prominent aortic knuckle and wide mediastinum are valuable clinical parameters and useful predictors for transradial access failure caused by tortuosity of the right subclavian/brachiocephalic arteries or aorta

    Minimally Invasive Approach in Surgical Management of Renal Neoplasms National Cancer Institute Experience

    Get PDF
    BACKGROUND: Minimally invasive nephrectomy is considered a technically challenging procedure requiring a long learning curve to reach acceptable warm ischemia time and perioperative complications. These minimally invasive techniques result in a shorter hospital stay and less post-operative pain. AIM: This study aims to demonstrate the National Cancer Institute experience regarding the benefits of laparoscopic and robot-assisted nephrectomy over open technique. METHODS: This is a retrospective descriptive cohort study including 62 patients with renal masses treated with nephrectomy whether partial, total or radical, 26 cases were treated by minimally invasive techniques (8 robotic and 18 laparoscopic), while 36 cases were treated by open technique. Inclusion criteria were patients between 20 and 70 years with renal neoplasm without renal vein thrombosis, with tumor stage T1 or T2 N0 M0. Exclusion criteria were patients with medical comorbidities that preclude surgical management or minimally invasive techniques and patients refusing surgery in general. RESULTS: Minimally invasive nephrectomy resulted in shorter hospital stay (mean hospital stay was 2.2 days for the minimally invasive group and 3.6 days for the open group) and less post-operative pain than open technique (p < 0.001 and = 0.002, respectively), while open technique resulted in shorter operation time (p = 0.039, mean operation time 147.8 min compared to 184.8 in the minimally invasive group). CONCLUSION: Minimally invasive nephrectomy (laparoscopic and robotic) resulted in less post-operative pain and shorter hospital stay compared to open technique despite consuming longer operation time which may be decreased by improving the learning curve of operating surgeons

    The use of latissimus dorsi mini-flap in partial breast reconstruction

    Get PDF
    Introduction: The cosmetic drawbacks of breast conserving surgery are asymmetry, nipple or skin retraction, and volume loss with unsatisfactory cosmetic outcome. The principle of Latissimus dorsi mini-flap (LDMF) is to use part of the Latissimus dorsi (LD) muscle as volume replacement to large breast defect up to 20 -30 % of the breast volume. Purpose: To evaluate (LDMF) as a volume replacement to large breast defect after wide local excision in different breast quadrants and the benefit of using this procedure regarding the cosmetic outcomes, patient satisfaction, procedure-related complications. Materials and Methods: The study was carried out at the National Cancer Institute, Cairo University, Egypt, from September 2017 to December 2018. Fifteen patients were selected. Wide local excision with post-resection defects of 20%-30% of breast volume were done. An inferolateral incision was done for both tumor resection and LDMF harvesting without any back scar. The patients were scheduled for regular follow up. Results: All the resection margins were negative. Mean Operative time was 176.6 minutes, the mean hospital stay was 2.47 days. The mean score for sensory preservation was 7.66. The mean of visual analogue score VAS was 8.33 with a score range from 8 to 9. The mean of the surgeon evaluation was 8.53. The median ranged from 8 to 9. Conclusion: LDMF makes BCS possible to a group of patients who are classically required mastectomy. It is particularly benefical to patients that responds poorly to neoadjuvant chemotherapy or with wide spreading DCIS

    Diagnostic value of portal venous pulsatility index in patients with high-risk nonalcoholic fatty liver disease

    Get PDF
    Background: As commonest form among liver diseases, nonalcoholic fatty liver disease (NAFLD) presents no symptoms. It is possible to use regular ultrasound scanning, which are always available in medical care centers everywhere, to quickly and quantitatively assess portal vein pulsatility. Objective: To evaluate the value of the portal venous pulsatility index for noninvasively diagnosing nonalcoholic fatty liver disease who are at high risk.Patients and Methods: The trial was a comparative cross-sectional trial involving 145 NAFLD patients, conducted in Radiodiagnosis Department, Faculty of Medicine, Zagazig University Hospitals. Abdominal ultrasound fibroscan, and Doppler US examinations of portal venous system were done to all patients.Results: Basal lab features, triphasic right hepatic vein flow pattern, and Doppler flow characteristics differed significantly between the two groups. Except for the BARD score, there was a high statistically significant difference between the two groups for venous pulsatility index values as well as all clinical risk scores. VPI, NAFLD-FS, and FIB-4 odds ratios all showed high significant differences between the two groups. Optimism-Corrected ROC AUC of VPI +NAFLD FS was 0.89, VPI + FIB-4 was 0.90, VPI+BARD score was 0.86 and VPI + APRI was 0.85. There was a high significant difference regarding VPI +NAFLD FS & VPI + FIB-4.Conclusion: High-risk NAFLD can be predicted using VPI and this could improve the effectiveness of frequently used clinical predictor tools

    Role of static fluid MR urography in detecting post urinary diversion complications

    Get PDF
    Aim of work: The aim of the study was to assess the diagnostic performance of static MR urography in detection of post cystectomy complications & the ability of static fluid MR urography in visualization of urinary tract segments.Material & methods: We prospectively reviewed 21 MR urograms with urinary diversion. The most common surgical procedures included Ileal conduit & Ileocecal neobladder diversion.Material & methods: Magnetic resonance urography examinations were performed with 1.5-T MR scanners. T2 weighted (static fluid) MR urography techniques were done, in addition to conventional T1- and T2-weighted axial and coronal sequences. Urinary tract was divided in different parts: pelvicalyceal systems, upper, mid and lower ureteric segments & the reservoir or conduit Imaging features of the urinary collecting systems were evaluated for their visualization and complications detection.Results: T2-weighted MR urography could demonstrate 95% of urinary tract segments & together with conventional MR sequences all urinary tract segments can be visualized. Urinary diversion related complications were encountered included in 15 patients (71.4%) & no urological complications were seen in 6 patients (28.6%).Conclusion: Comprehensive T2-weighted MR urography is an effective imaging method for the visualization of the urinary system and detection of early and late postoperative complications in patients with urinary diversion.Keywords: MR urography, Urinary diversion, Cancer bladde

    Ultrasound-Guided Erector Spinae Plane Block: A Comparative Study to Assess its Analgesic Efficacy in Pediatric Patients Undergoing Aortic Coarctation Repair

    Get PDF
    Background: Effective postoperative analgesia is an important aspect of both anesthetic practice and postoperative outcomes. Thoracotomy for the repair of coarctation of the aorta is a painful surgical procedure; inadequate postoperative analgesia may result in postoperative respiratory complications with the possible prolonged need for oxygen therapy. In addition, paradoxical hypertension is a well-recognized complication of repair. We hypothesize that erector spinae plane block (ESPB) by providing adequate analgesia and blocking sympathetic stimulation may reduce opioid consumption, accelerate weaning of oxygen therapy, and reduce the incidence of early postoperative paradoxical hypertension. Material and methods: Open-labeled randomized controlled trial carried out on 40 patients divided into two groups. Group (B) received ESPB before the skin incision and group (C), the control group received no block. Results: Patients who received ESPB had significantly less intraoperative fentanyl consumption than the control group (P-value<0.001), and significantly less postoperative fentanyl consumption by 50% than the control group in the first 12 hours 2.025 ±0.273 μg/kg and 4.05 ±0.527 μg/kg respectively (P-value<0.001). while there was no statistically significant difference between both groups regarding the incidence of postoperative vasodilator infusion for paradoxical hypertension (P-value=0.054), the pediatric anesthesia emergence delirium (PAED) (P-value=0.06) nor the time to wean oxygen supply (P-value=0.49).  Conclusion: Erector spinae plane block effectively reduces postoperative pain in pediatric patients undergoing repair of coarctation of the aorta. However, it did not significantly accelerate weaning from oxygen therapy nor reduce the incidence of vasodilator use for postprocedural hypertension

    Application of machine learning algorithms to evaluate the influence of various parameters on the flexural strength of ultra-high-performance concrete

    Get PDF
    The effect of various parameters on the flexural strength (FS) of ultra-high-performance concrete (UHPC) is an intricate mechanism due to the involvement of several inter-dependent raw ingredients. In this digital era, novel artificial intelligence (AI) approaches, especially machine learning (ML) techniques, are gaining popularity for predicting the properties of concrete composites due to their better precision than typical regression models. In addition, the developed ML models in the literature for FS of UHPC are minimal, with limited input parameters. Hence, this research aims to predict the FS of UHPC considering extensive input parameters (21) and evaluate each their effect on its strength by applying advanced ML approaches. Consequently, this paper involves the application of ML approaches, i.e., Support Vector Machine (SVM), Multi-Layer Perceptron (MLP), and Gradient Boosting (GB), to predict the FS of UHPC. The GB approach is more effective in predicting the FS of UHPC precisely than the SVM and MLP algorithms, as evident from the outcomes of the current study. The ensembled GB model determination coefficient (R2) is 0.91, higher than individual SVM with 0.75 and individual MLP with 0.71. Moreover, the precision of applied models is validated by employing the k-fold cross-validation technique. The validity of algorithms is ensured by statistical means, i.e., mean absolute error and root mean square errors. The exploration of input parameters (raw materials) impact on FS of UHPC is also made with the help of SHAP analysis. It is revealed from the SHAP analysis that the steel fiber content feature has the highest influence on the FS of UHPC
    • …
    corecore