Alignment and phylogenetic analysis of type II DNA topoisomerases

DNA topoisomerases have been evolved to solve the topological problems of DNA during replication, transcription, recombination and segregation. Discovery of several new enzymes and their characterization has necessitated this compilation. This analysis shows the distinct evolutionary relatedness of type II DNA topoisomerases. A striking feature is the absence of a contiguous stretch of about 160 amino acids in one of the subunits of prokaryotic type II enzymes, which might have important implications to their structure and function

Test for the Equality of Partial Correlation Coefficients for Two Populations

A likelihood ratio test for the equality of two partial correlation coefficients based on two independent multinormal samples has been derived. The large sample Z-test for the same problem has also been discussed. The power analysis of the two tests is obtained. It has been found that the approximate likelihood ratio (ALR) test showed consistently better results than Z -test in terms of power. The size of the ALR test is slightly more than the alpha level. The ALR test is recommended strongly for use in practice

Preparation of Undoped and Phosphorus Doped μc-Si:H Films: Effect of Extended Period of Hydrogen Plasma Annealing in Interrupted Growth

Interrupted growth and H-plasma annealing of stacking layers of Si:H film resulted in a significant improvement in material properties towards microcrystallization. Increase of dark conductivity and reduction of optical absorption due to extended period of hydrogen plasma exposure was noted. An associated improvement in the network structure towards crystallinity was observed by Raman, TEM and XRD studies. Highly conducting ( σD ~ 6 × 10-3 s. cm-1) undoped mc-Si:H films have been prepared at significantly low thickness of 650 Å. P-doped mc-Si:H films having conductivity ~ 26.2 S.cm-1 were obtained from very low level of PH3 dilution. Large number of dopants introduce additional defects at the grain boundary and inhibits the crystallization process

Current–voltage characteristics of polar heterostructure junctions

We report calculations that show that a metal–polar semiconductor heterostructure can exhibit highly controllable nonlinear current–voltage characteristics. A change in barrier thickness can alter the characteristics from Schottky-like to ohmic in different bias regimes. The origin of these unusual effects is a large electric field (>106 V/cm)(>106 V/cm) and high sheet charge(∼1013–1014cm−2)(∼1013–1014cm−2) without doping, in the polar heterostructure. Theoretical calculation of the tunneling current density in these systems is done in this work. The results indicate that very interesting nonlinear behavior is shown by these systems, even in the undoped case. The choice of suitable compositions of the materials and thicknesses can be used to tailor devices with desired characteristics. © 2002 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71184/2/JAPIAU-91-5-2989-1.pd

A comparative study of proximal femoral fracture fixation with proximal femoral nail and dynamic hip screw and plating

Background: Trochanteric fractures are one of the commonest injuries sustained predominantly in patients over sixty years of age. They are three to four times more common in women. These usually occur through bone affected by osteoporosis; trivial fall being most common mechanism of injury Approximately 10-30% of patients die within one year of an intertrochanteric fracture.Methods: A prospective study comprising of patients identified for surgical treatment of fracture in the intertrochanteric region of femur admitted to Sri Siddhartha Medical College, Tumkur from 2016 to 2017 where 30 patients with 30 intertrochanteric fractures of femur were selected with equal distribution of 15 dynamic hip screw devices and 15 intramedullary devices.Results: The purpose of the present study is to verify theoretical advantages of intramedullary device over the dynamic hip screw devices and also whether it actually alters the eventual functional outcome of the patient. Excellent results were seen in 2 patients (13.3%) in the DHS group and in 6 patients (40%) in the PFN group. The overall functional outcome of patients treated with the PFN was significantly better than those treated with DHS (p=0.037). However when we compared the stable and unstable fractures separately, we found that there was no significant difference in the outcomes of the stable fractures in the two groups (p=0.198).Conclusions: We conclude that in stable intertrochanteric fractures, both the PFN and DHS have similar outcomes. However, in unstable intertrochanteric fractures the PFN has significantly better outcomes in terms of earlier restoration of walking ability as it is an intramedullary implant which can tolerate higher cylindrical loading when compared to DHS type of implants. In addition, as the PFN requires shorter operative time and smaller incision, it has distinct advantages over DHS even in stable intertrochanteric fractures. Hence, in our opinion, PFN may be the better fixation device for most intertrochanteric fractures

INFLUENCE OF HYDROXYPROPYL-β-CYCLODEXTRIN ON REPAGLINIDE RELEASE FROM SUSTAINED RELEASE BIOADHESIVE BUCCAL TABLETS

Objective: The purpose of this investigation was to study the influence of cyclodextrin complexation on development of sustained release bio-adhesive repaglinide tablets for buccal delivery. Methods: Based on preliminary phase solubility studies, solid complexes prepared by freeze-drying method in 1:1 molar ratio were selected and characterized by Fourier transform infrared spectroscopy to corroborate the fact of complex formation. The sustained release repaglinide tablets were produced by direct compression and this drug or complexed –loaded hydrophilic matrices using HPMC, Sodium CMC and Carbopol as muco-adhesive polymers were assessed for in vitro bioadhesion strength, in vitro release modulation, surface pH, % moisture absorption and ex vivo permeation through porcine buccal membrane. Results: When the drug was incorporated as repaglinide-Hydroxypropyl-β-Cyclodextrin (HP-β-CD) freeze-dried product, total amount of drug permeated from the tablet through epithelium in about 12 hrs, displaying a constant release regimen after a transient period. The effect of HP-β-CD incorporation on the release mechanism was rationalized on the basis of the interplay of different physical phenomena: erosion and swelling of the tablet, drug dissolution, and complex formation. Formulation F10 showed % moisture absorption of 23.46 for 4hrs, surface pH 6.9±0.015, Peak detachment force 3.65±0.18 N, Work of adhesion 1.12±0.10 mJ, and in vitro drug release 98.31% in 6h. The feasibility of buccal administration of repaglinide was assessed by permeation experiments on excised mucosa of pig. The ex vivo permeation studies demonstrated that the matrix tablets containing repaglinide–HP-β-CD (F10) solid complex exhibited significantly higher drug permeation (92.18 % for 12hrs) compared to all of the other formulations tested, which could be attributed to both, the presence of the polymers, and the drug-cyclodextrin complexation. The flux was found to be increased by 1.12-1.37 folds with a permeability coefficient of 0.017-0.018. Conclusion: The results demonstrate that the formulations with inclusion complexes afford high utility as a trans-mucosal drug delivery system for improved drug release and permeability.   KEY WORDS: Repaglinide, Freeze drying, HP-β-CD complexation, Bioadhesion, Ex-vivo permeation, Solubility &nbsp

Probabilistic Performance Index based Contingency Screening for Composite Power System Reliability Evaluation

Composite power system reliability involves assessing the adequacy of generation and transmission system to meet the demand at major system load points. Contingency selection was being the most tedious step in reliability evaluation of large electric systems. Contingency in power system might be a possible event in future which was not predicted with certainty in earlier research. Therefore, uncertainty may be inevitable in power system operation. Deterministic indices may not guarantee the randomness in reliability assessment. In order to account for volatility in contingencies, a new performance index proposed in the current research. Proposed method assimilates the uncertainty in computational procedure. Reliability test systems like Roy Billinton Test System-6 bus system and IEEE-24 bus reliability test systems were used to test the effectiveness of a proposed method

Mesoporous Alumina Supported NiMo Catalysts for Residue Conversion

AbstractMesoporous alumina catalyst supports with high surface area (upto458m2/g) and pore volume (upto1.55cm3/g) have been synthesized through Sol-gel process using non-ionic block copolymers as a template. Nitrogen gas adsorption, FT-IR and transmission electron microscopy were performed to determine the structure of these synthesized materials. Hydroprocessing of vacuum residue with prepared NiMo catalysts supported on mesoporous alumina was conducted in a batch reactor. The hydroprocessing reactions were performed at 400-420˚C with hydrogen pressure of 100bar. High conversions with low coke formation and high quality of liquid products (12.46wt% of naphtha, 31 wt% of middle distillates, 21wt% of VGO and 36wt% of residue) is obtained with the catalyst having large pore diameter and high pore volume