The biology and predatory potential of notonectid bug, Enithares indica (Fabr) against mosquito larvae

An 18-year-old white male developed severe hepatic veno-occlusive disease (VOD) during an autologous bone marrow transplant for primary refractory nodular sclerosing Hodgkin's disease. As a result of VOD-induced hepatic dysfunction, coagulation studies revealed depression of vitamin K dependent procoagulant factor VII. Intravenous recombinant tissue plasminogen activator 20 mg over h on 4 consecutive days and continuous heparin infusion (1000 unit bolus followed by 150 units/kg/day) resulted in rapid reversal of the VOD syndrome. During treatment, procoagulant factors II, VII, IX and X levels increased indicating the return of hepatic synthesizing capacity. Factor V levels, which were elevated pre-therapy, also rose dramatically. Plasma antigen levels of protein C, a natural anticoagulant, remained severely depressed. No clinical evidence of bleeding and only minimal systemic fibrinolysis was noted. Despite concerns regarding the use of lytic therapy in a thrombocytopenic post-BMT patient, serial measurements of coagulation parameters during severe VOD suggested that low dose rt-PA improved portions of the systemic hemostatic profile.     

Characterizing bubble dynamics created by high-intensity focused ultrasound for the delivery of antibacterial nanoparticles into a dental hard tissue

Hig hintensity focused ultrasound (HIFU) has been applied for drug delivery in various disease conditions. Delivery of antibacterial-nanoparticles into dental hard tissues may open up new avenues in the treatment of dental infections. However, the basic mechanism of bubble dynamics, its characterization, and working parameters for effective delivery of nanoparticles, warrants further understanding. This study was conducted to highlight the basic concept of HIFU and the associated bubble dynamics for the delivery of nanoparticles. Characterization experiments to deliver micro-scale particles into simulated tubular channels, activity of ultrasonic bubbles, and pressure measurement inside the HIFU system were conducted. Subsequently, experiments were carried out to test the ability of HIFU to deliver nanoparticles into human dentine using field emission scanning electron micrographs (FESEM) and elemental dispersive X-ray analysis (EDX). The characterization experiments showed that the bubbles collapsing at the opening of tubular channels were able to propel particles along their whole length. The pressure measured showed sufficient negative and positive pressure suggesting that the bubble grew to a certain size before collapsing, thus enabling the particles to be pushed. The FESEM and EDX analysis highlighted the ability of HIFU to deliver nanoparticles deep within the dentinal tubules. This study highlighted the characteristics and the mechanism involved of the bubbles generated by the HIFU and their capability to deliver nanoparticles.     

Fatigue crack propagation model and size effect in concrete using dimensional analysis

It is well known that fatigue in concrete causes excessive deformations and cracking leading to structural failures. Due to quasi-brittle nature of concrete and formation of a fracture process zone, the rate of fatigue crack growth depends on a number of parameters, such as, the tensile strength, fracture toughness, loading ratio and most importantly the structural size. In this work, an analytical model is proposed for estimating the fatigue crack growth in concrete by using the concepts of dimensional analysis and including the above parameters. Knowing the governed and the governing parameters of the physical problem and by using the concepts of self-similarity, a relationship is obtained between different parameters involved. It is shown that the proposed fatigue law is able to capture the size effect in plain concrete and agrees well with different experimental results. Through a sensitivity analysis, it is shown that the structural size plays a dominant role followed by loading ratio and the initial crack length in fatigue crack propagation.