Investigation of Instabilities in a Folded-Waveguide Sheet-Beam TWT

Particle-in-cell (PIC) simulation was used for analyzing the instabilities due to zero-drive oscillations in a 220-GHz folded-waveguide (FW) traveling-wave tube. The equivalent circuit analysis based on the transmission line approach was used for the parametric design of the FW structures (FWSs) with circular and rectangular (horizontal and vertical) beam holes. Experimental validations with reference to the dispersion and interaction impedance characteristics were carried out on a scaled model of the slow wave structure in the Ku band. The oscillations observed in various configurations of the FWS were subsequently analyzed using the Brillouin diagram. The FWS with horizontal-rectangular beam hole was found to have a better immunity to instability compared to the other two configurations. © 1963-2012 IEEE

Incidence and risk factors of post-molar gestational trophoblastic neoplasia: a prospective study

Background: Gestational trophoblastic disease (GTD) is a group of disorders arising from abnormal trophoblastic cells. Gestational trophoblastic neoplasia (GTN) is a malignant counterpart of GTD. In the earlier era, morbidity and mortality associated with GTD was very high, 90-95% presenting with metastatic GTN in 1980’s. Methods: This is a prospective study to analyze the incidence and to identify the risk factors of post-molar GTN and to evaluate the role of Beta-hCG level as a predictive factor of post-molar GTN, conducted in the department of Obstetrics and Gynecology, Institute of Maternal and Child Health (IMCH), Government Medical College, Kozhikode, on patients attending the vesicular mole(VM) clinic. Group A (remission group - was diagnosed after 6 months of follow-up with undetectable Beta-hCG values) and Group B (post-molar GTN). The two groups were compared for identifying risk factors. Results: There were 79 cases of molar pregnancy registered in VM clinic with an incidence of 4.87/1000 deliveries. Of the 79 patients with GTD, 17 were diagnosed to have GTN during follow-up with an incidence of 21.51% of GTD. Incidence of post-molar GTN were significantly more among patients with history of previous molar pregnancy. The median Beta-hCG level at 2 weeks post-evacuation and the ratio of Beta-hCG levels at 1week to 2 weeks post-evacuation was found to be highly predictive of post-molar GTN. Conclusions: Incidence of GTD was higher compared to international studies. The ratio of post-evacuation Beta-hCG at 1 week to Beta-hCG at 2 weeks is the most reliable predictor of post-molar GTN.

DACLATASVIR DIHYDROCHLORIDE MICROSPHERES, PROCESS PARAMETERS FOR ENHANCED PERMEABILITY AND LIVER TARGETING

Objectives: Daclatasavir dihydrochloride (DCLD) is used to treat hepatitis C. DCLD can be used to patients with all stages of compensated liver disease including cirrhosis. The aim of the present study was to develop DCLD microspheres to improve the permeation and maximum accumulation in the liver and in vitro evaluation. Methods: DCLD microspheres were prepared with chitosan polymer using emulsion crosslinking technique. Twelve formulations were prepared, that is, F1-F12. The microspheres were evaluated for morphology, particle size, encapsulation efficiency, % yield, and permeability. FTIR studies were conducted on optimized formulation to check the drug-excipient compatibility. Results: The particle size of microspheres was in the range of 11.50±0.08 μm to 98.50±0.05 μm. Encapsulation efficiency of the formulations was observed in the range 47.8–69.2%. The ex vivo permeation studies revealed that 83.3±0.1% of drug was diffused from microspheres in 60 min, whereas from pure drug 49±0.7% of drug was diffused in 60 min. Conclusion: DCLD microspheres were shown good permeability when compared to pure drug which will improve the absorption

Application of Biosorption for Removal of Heavy Metals from Wastewater

Fresh water accounts for 3% of water resources on the Earth. Human and industrial activities produce and discharge wastes containing heavy metals into the water resources making them unavailable and threatening human health and the ecosystem. Conventional methods for the removal of metal ions such as chemical precipitation and membrane filtration are extremely expensive when treating large amounts of water, inefficient at low concentrations of metal (incomplete metal removal) and generate large quantities of sludge and other toxic products that require careful disposal. Biosorption and bioaccumulation are ecofriendly alternatives. These alternative methods have advantages over conventional methods. Abundant natural materials like microbial biomass, agro-wastes, and industrial byproducts have been suggested as potential biosorbents for heavy metal removal due to the presence of metal-binding functional groups. Biosorption is influenced by various process parameters such as pH, temperature, initial concentration of the metal ions, biosorbent dose, and speed of agitation. Also, the biomass can be modified by physical and chemical treatment before use. The process can be made economical by regenerating and reusing the biosorbent after removing the heavy metals. Various bioreactors can be used in biosorption for the removal of metal ions from large volumes of water or effluents. The recent developments and the future scope for biosorption as a wastewater treatment option are discussed

RASPBERRY PI BASED WEARABLE RFID TAG DESIGN FOR MEDICAL CARE

With the upcoming aging society and emerging of some newly discovered chronic diseases, the demand of hospital nursing for elderly patients had been significantly increased. It is a critical issue for health worker to provide a comprehensive, proactive health care in hospital, especially for those disabled patients who are unable to speak or behave themselves. This study proposes an innovative wearable RFID tag which embedded body temperature monitoring sensor, and equipped with automatic identification and localization, real-time emergency notification for healthcare workers. Additionally operating with the intelligent backend system architecture this system can also provide immediate physician advice in case if emergency situation happens without doctors near the side. The result of the study provides a ubiquitous medical care throughout whole hospital, and the newly invented tag may bring a significant change to normal health care process especially in patient care

Comparative analysis of structural variations due to genome shuffling of Bacillus subtilis VS15 for improved cellulase production

Cellulose is one of the most abundant and renewable biomass products used for the production of bioethanol. Cellulose can be efficiently hydrolyzed by Bacillus subtilis VS15, a strain isolate obtained from decomposing logs. A genome shuffling approach was implemented to improve the cellulase activity of Bacillus subtilis VS15. Mutant strains were created using ethyl methyl sulfonate (EMS), N-Methyl-N′ nitro-N-nitrosoguanidine (NTG), and ultraviolet light (UV) followed by recursive protoplast fusion. After two rounds of shuffling, the mutants Gb2, Gc8, and Gd7 were produced that had an increase in cellulase activity of 128%, 148%, and 167%, respectively, in comparison to the wild type VS15. The genetic diversity of the shuffled strain Gd7 and wild type VS15 was compared at whole genome level. Genomic-level comparisons identified a set of eight genes, consisting of cellulase and regulatory genes, of interest for further analyses. Various genes were identified with insertions and deletions that may be involved in improved celluase production in Gd7.. Strain Gd7 maintained the capability of hydrolyzing wheatbran to glucose and converting glucose to ethanol by fermentation with Saccharomyces cerevisiae of the wild type VS17. This ability was further confirmed by the acidified potassium dichromate (K2Cr2O7) method

Response surface methodology-artificial neural network based optimization and strain improvement of cellulase production by Streptomyces sp.

ABSTRACT Thirty seven different colonies were isolated from decomposing logs of textile industries. From among these, a thermotolerant, grampositive, filamentous soil bacteria Streptomyces durhamensis vs15 was selected and screened for cellulase production. The strain showed clear zone formation on CMC agar plate after Gram’s iodine staining.  Streptomyces durhamensis vs15 was further confirmed for cellulase production by estimating the reducing sugars through dinitrosalicylic acid (DNS) method. The activity was enhanced by sequential mutagenesis using three mutagens of ultraviolet irradiation (UV), N methyl-N’-nitro-N-nitrosoguanidine (NTG) and Ethyl methane sulphonate (EMS). After mutagenesis, the cellulase activity of GC23 (mutant) was improved to 1.86 fold compared to the wild strain (vs15). Optimal conditions for the production of cellulase by the GC 23 strain were evaluated using Response Surface Methodology (RSM) and Artificial Neural Network (ANN). Effect of pH, temperature, duration of incubation, , and substrate concentration on cellulase production were evaluated. Optimal conditions for the production of cellulase enzyme using Carboxy Methyl Cellulase as a substrate are 55 oC of temperature, pH of 5.0 and incubation for 40 h. The cellulase activity of the mutant Streptomyces durhamensis GC23 was further optimised to 2 fold of the activity of the wild type by RSM and ANN