In-hospital outcomes of premature infants with severe bronchopulmonary dysplasia

To characterize in-hospital outcomes of premature infants diagnosed with severe bronchopulmonary dysplasia

The Effect of Cyclooxygenase-2 Expression on Tumor Volume Response in Patients Treated with Radiotherapy for Uterine Cervical Cancer

We investigated the correlation between Cyclooxygenase-2 (COX-2) expression and the tumor response in patients with cervical cancer that were treated with curative radiotherapy (RT). Fifty-seven patients with squamous cell carcinoma were treated with concurrent radiochemotherapy (CRCT, n=29) or RT alone (n=28). The response of each patient was evaluated by three serial Magnetic Resonance Imaging examinations: before the start of RT, at four weeks after the start of RT (mid-RT) and at four weeks after the completion of RT (post-RT). Forty-three patients had positive COX-2 expression. The COX-2 negative patients achieved a higher rate of complete response (CR) at mid-RT than did the COX-2 positive patients (28.6% vs. 7.0%, P=0.054), but not at post-RT (64.3% vs. 69.8%). The initial tumor volume was a significant predictor of CR at mid-RT (P=0.003) and post-RT (P=0.004). The multivariate analysis showed that the initial tumor volume (at mid-RT and post-RT) and CRCT (at post-RT) were significant predictors of CR; however, the COX-2 expression was not. In conclusion, the COX-2 expression status has no significant correlation with the tumor response. Further studies on the changes in COX-2 expression levels during RT may be helpful for determination of its role in the tumor response to treatment and patient prognosis

A systematic study on Pt based, subnanometer-sized alloy cluster catalysts for alkane dehydrogenation: effects of intermetallic interaction

Platinum-based bimetallic nanoparticles are analyzed by the application of density functional theory to a series of tetrahedral Pt3X cluster models, with element X taken from the P-block, preferably group 14, or from the D-block around group 10. Almost identical cluster geometries allow a systematic investigation of electronic effects induced by different elements X. Choosing the propane-to-propene conversion as the desired dehydrogenation reaction, we provide estimates for the activity and selectivity of the various catalysts based on transition state theory. No significant Brønsted-Evans-Polanyi-relation could be found for the given reaction. A new descriptor, derived from an energy decomposition analysis, captures the effect of element X on the rate-determining step of the first hydrogen abstraction. Higher activities than obtained for pure Pt4 clusters are predicted for Pt alloys containing Ir, Sn, Ge and Si, with Pt3Ir showing particularly high selectivity

Manufacture of liposomes - a review

A brief introduction to liposomes and the methods of their preparation is presented. Various laboratory-scale and large-scale methods of preparation of liposomes are reviewed. They include some of the recent techniques like the 'bubble' method, microencapsulation, microfluidization, LLC method, ethanol injection, freon injection and detergent dialysis and the traditional methods like hydration, sonication and reverse phase evaporation. This paper also discusses the crucial problems like stability and quality control in the commercialization of liposomes and the methods (such as lyophilization and the various characterization techniques like electron microscopy and gel permeation chromatography) to overcome them, Also discussed is the mechanism of vesicle formation

Improving the Energy Efficiency of a Clock Synchronization Protocol for WSNs using a TDMA-based MAC Protocol

Clock synchronization protocols in wireless sensor networks (WSNs) provide a uniform notion of time which is required by both system as well as application level programs of WSNs. Since nodes have limited energy, it is required that the energy consumed by the clock synchronization protocols is as minimum as possible. Synchronous clock synchronization protocols execute their clock synchronization process at each node, roughly during the same real-time interval, called synchronization phase. The energy consumed by these protocols depends on the duration of the synchronization phase and how frequently the synchronization phase is executed. Hence, to minimize the energy consumption by each node, the duration of synchronization phase should be as small as possible, and the interval between consecutive synchronization phases as large as possible. Due to different drift rates of the clocks, the synchronization phases at different nodes drift apart and special techniques are required to keep them in sync. Keeping synchronization phases at neighbouring nodes in sync helps to reduce the synchronization phase. In this paper, we propose a novel technique using TDMA-based MAC protocol to keep the synchronization phases at neighbouring nodes in sync much more tightly than the existing techniques. We have applied the technique in the improved weighted-average based clock synchronization (IWICS) protocol to reduce the synchronization phase considerably and the modified TDMA-based IWICS protocol is named TIWICS protocol. This reduction in energy consumption is achieved without reducing the synchronization accuracy. Simulation results obtained using Castalia network simulator and the experimental results obtained using a testbed of WSN consisting of a few TelosB motes confirm the effectiveness of the approach