Advanced gearbox technology

An advanced 13,000 HP, counterrotating (CR) gearbox was designed and successfully tested to provide a technology base for future designs of geared propfan propulsion systems for both commercial and military aircraft. The advanced technology CR gearbox was designed for high efficiency, low weight, long life, and improved maintainability. The differential planetary CR gearbox features double helical gears, double row cylindrical roller bearings integral with planet gears, tapered roller prop support bearings, and a flexible ring gear and diaphragm to provide load sharing. A new Allison propfan back-to-back gearbox test facility was constructed. Extensive rotating and stationary instrumentation was used to measure temperature, strain, vibration, deflection and efficiency under representative flight operating conditions. The tests verified smooth, efficient gearbox operation. The highly-instrumented advanced CR gearbox was successfully tested to design speed and power (13,000 HP), and to a 115 percent overspeed condition. Measured CR gearbox efficiency was 99.3 percent at the design point based on heat loss to the oil. Tests demonstrated low vibration characteristics of double helical gearing, proper gear tooth load sharing, low stress levels, and the high load capacity of the prop tapered roller bearings. Applied external prop loads did not significantly affect gearbox temperature, vibration, or stress levels. Gearbox hardware was in excellent condition after the tests with no indication of distress

Analysis of coupled shear wall tall buildings

Abstract unavailable please refer to PD

Literature review of the mechanisms of acute kidney injury secondary to acute liver injury

People exposed to liver ischaemia reperfusion (IR) injury often develop acute kidney injury and the combination is associated with significant morbidity and mortality. Molecular mediators released by the liver in response to IR injury are the likely cause of acute kidney injury (AKI) in this setting, but the mediators have not yet been identified. Identifying the mechanism of injury will allow the identification of therapeutic targets which may modulate both liver IR injury and AKI following liver IR injury

The role of preoperative computed tomography in surgical planning of intertrochanteric femur fractures fixation

Background: A precise preoperative evaluation of stability of intertrochanteric fractures is crucial for surgical planning. Three dimensional CT scanning is a useful tool for understanding the exact type of fracture pattern.  Methods: A prospective study included 40 patients with intertrochanteric femoral fractures. They were classified into stable and unstable intertrochanteric fractures according to the X-ray based AO/OTA classification and according to Nakano 3D-CT classification and both classifications were correlated. The patients were operated on using dynamic hip screw (DHS) and were assessed radiologically and clinically by Harris hip score (HHS) after 6 months. Results: There was significant statistical difference (p=0.031) and relation (p<0.001) between X-ray based AO/OTA classification and 3D-CT classification. Six cases from the 24 cases with stable pattern in AO/OTA system have unstable patterns in the 3D-CT (25%) and their percent from the 22 unstable patterns in 3D-CT is 27.27% and their percent from the total number of patients in the study is 15%.  Conclusions: The superolateral support in the form of the greater trochanter which affects the lateral wall thickness is as important as the posteromedial lesser fragment in assessing the stability of the fracture pattern.

Ethoxyquin Inhibits the Progression of Murine Ehrlich Ascites Carcinoma through the Inhibition of Autophagy and LDH

Cancer cells exhibit an increased glycolysis rate for ATP generation (the Warburg effect) to sustain an increased proliferation rate. In tumor cells, the oxidation of pyruvate in the Krebs cycle is substituted by lactate production, catalyzed by LDH. In this study, we use ethoxyquin (EQ) as a novel inhibitor to target LDH in murine Ehrlich ascites carcinoma (EAC) and as a combination therapy to improve the therapeutic efficacy of the conventional chemotherapy drug, cisplatin (CIS). We investigated the anti-tumor effect of EQ on EAC-bearing mice and checked whether EQ can sustain the anti-tumor potential of CIS and whether it influences LDH activity. Treatment with EQ had evident anti-tumor effects on EAC as revealed by the remarkable decrease in the expression of the anti-apoptotic gene Bcl-2 and by a significant increase in the expression of apoptotic genes (BAX and caspase-3). EQ also caused a significant decrease in the autophagic activity of EAC cells, as shown by a reduction in the fluorescence intensity of the autophagosome marker. Additionally, EQ restored the altered hematological and biochemical parameters and improved the disrupted hepatic tissues of EAC-bearing mice. Co-administration of EQ and CIS showed the highest anti-tumor effect against EAC. Collectively, our findings propose EQ as a novel inhibitor of LDH in cancer cells and as a combinatory drug to increase the efficacy of cisplatin. Further studies are required to validate this therapeutic strategy in different cancer models and preclinical trials

Effect of oxytocin infusion versus tranexamic acid on reducing blood loss during hysteroscopic myomectomy: a randomized controlled trial

Background: Women undergoing hysteroscopic myomectomy are prone to significant blood loss and hematological disturbances. Oxytocin is a uterotonic drug, used mainly in obstetric practice. Tranexamic acid is a haemostatic drug that has been used to reduce blood loss after trauma and in many surgeries. The aim of our study was to compare the safety and efficacy of oxytocin versus tranexamic acid in reducing perioperative blood loss during hysteroscopic myomectomy.Methods: This study included 60 patients scheduled for hysteroscopic myomectomy allocated into 2 groups: group A: received 10 mg/kg of tranexamic acid slowly intravenous after induction of anesthesia, while group B: received infusion of 10 IU of oxytocin at a rate of 400 mIU/min throughout the procedure. Preoperative and postoperative hemoglobin and hematocrit levels, need for blood transfusion, duration of operation, complications and medications adverse effects were recorded.Results: The 2 groups were comparable in terms of the mean difference between preoperative and postoperative hemoglobin a hematocrit levels, operative time, operative complication and medications’ adverse effects. No patients needed blood component transfusion in either group.Conclusions: It can be concluded that tranexamic acid and oxytocin are equally effective in reducing blood loss and transfusion requirements during hysteroscopic myomectomy with comparable good safety profiles. Both of them can be used according to availability and surgeon preferences