2,219 research outputs found
Seasonal variation of the water quality parameters and its influences in the mahanadi estuary and near coastal environment, east coast of India
The distributions of water quality parameters viz. temp, salinity, dissolved oxygen (DO), biochemical oxygen demand (BOD), total suspended substances (TSS), nutrients NO 2-N, NO 3-N, NH 4-N, PO 4-P, SiO 4-Si, total nitrogen (TN), total phosphorous (TP) and Chlorophyll-a (Chl-a) were studied in the Mahanadi river and costal environment of Paradip in two different seasons i.e. post-monsoon and summer during 2006-2007. Results of nutrient concentrations were exhibited higher indicates that large inputs possibly from two major fertilizer plants, municipal sewage from Paradip town and agricultural runoff. In the estuary most of the nutrients showed higher values (NO 3 7.23 μmol/l, NH 4 6.32 μmol/l, PO 4 16.03 μmol/l and SiO 4 15.32 μmol/l) during post-monsoon as compared to the costal stations. The PO 4 TN, TP and SiO 4-Si showed a well-defined pattern of distribution with higher concentration in estuarine water of Mahanadi estuary during summer
In-vitro Release Study of Carvedilol Phosphate Matrix Tablets Prepared with Hydroxypropyl Methylcellulose
Purpose: To evaluate the effect of two molecular weight grades of hydroxypropyl methylcellulose on the release characteristics of carvedilol phosphate matrix tablets.Methods: Matrix tablets containing carvedilol phosphate were prepared from 27 formulations in three batch series coded A, B and C, each containing 9 formulations. Each batch incorporated different ratios of two molecular weight grades of hydroxypropyl methylcellulose (Methocel® K4M CR and K15M CR) used as release retarding agents. Microcrystalline cellulose (Avicel PH 101), starch (Sta-Rx 1500) and lactose monohydrate were used as diluents in the formulations while the effect of sodium lauryl sulphate (wetting agent) was studied for some of the formulations. The tablets were characterized for carvedilol phosphate release in both simulated gastric and intestinal fluids. The data were subjected to different models in order to determine their release kinetics and mechanisms.Results: All the batches released more than 50 % of their carvedilol content in 12 h when Methocel® K4M CR and K15M CR constituted 18 % and 15 % of the matrix, respectively. Avicel® PH 101 decreased while Starch 1500 and lactose monohydrate increased drug release. Drug release mechanism was predominantly diffusion.Conclusion: By using varying combinations of two molecular weight grades of hydroxypropyl methylcellulose as the matrix, controlled or sustained release carvedilol tablets of varying release characteristics can be prepared
Environmental quality assessment of Treis Island, Nicobar, India
The physico-chemical, biological and microbiological parameters of surface seawater was studied at Tries Island during a survey in 2009. The physico-chemical parameters like silicate and inorganic phosphate concentration varied significantly from 3.53 to 4.22 and 0.05 to 0.09 μmol/L, respectively at Tries Island. The zooplankton population density ranged from 4696 to 8207 Nos./m3 and the dominant group was Copepod. The zooplankton biomass also varied significantly from 0.31 to 0.72 ml/m3. The phytoplankton density and species number also varied significantly from 1020 to 1220 Nos. /L and 25 to 31 numbers, respectively. Soleniae dominated in coastal waters of Treis Island. Chlorophyll-a, and phaeophytin concentration varied between 0.12 to 0.24 and 0.06 to 0.27 mg/m3, respectively. The chlorophyll-a concentration variation was significant. Apart from that noise level, soil and plant diversity were also investigated. Soil parameters indicated its fertile nature which is being utilized for horticulture by tribal community living in the neighbouring islands. The present study gives an account of the existing environmental quality in and around the island, providing a baseline scenario to assess the environmental impacts due to developments in the future. This study also provides comparison between populated and unpopulated coastal bay/marine ecosystems
Bacteria in cancer therapy: a novel experimental strategy
Resistance to conventional anticancer therapies in patients with advanced solid tumors has prompted the need of alternative cancer therapies. Moreover, the success of novel cancer therapies depends on their selectivity for cancer cells with limited toxicity to normal tissues. Several decades after Coley's work a variety of natural and genetically modified non-pathogenic bacterial species are being explored as potential antitumor agents, either to provide direct tumoricidal effects or to deliver tumoricidal molecules. Live, attenuated or genetically modified non-pathogenic bacterial species are capable of multiplying selectively in tumors and inhibiting their growth. Due to their selectivity for tumor tissues, these bacteria and their spores also serve as ideal vectors for delivering therapeutic proteins to tumors. Bacterial toxins too have emerged as promising cancer treatment strategy. The most potential and promising strategy is bacteria based gene-directed enzyme prodrug therapy. Although it has shown successful results in vivo yet further investigation about the targeting mechanisms of the bacteria are required to make it a complete therapeutic approach in cancer treatment
Household Transmission of Rotavirus in a Community with Rotavirus Vaccination in Quininde, Ecuador
Background: We studied the transmission of rotavirus infection in households in peri-urban Ecuador in the vaccination era.
Methods: Stool samples were collected from household contacts of child rotavirus cases, diarrhea controls and healthy controls following presentation of the index child to health facilities. Rotavirus infection status of contacts was determined by RT-qPCR. We examined factors associated with transmissibility (index-case characteristics) and susceptibility (householdcontact
characteristics).
Results: Amongst cases, diarrhea controls and healthy control household contacts, infection attack rates (iAR) were 55%, 8% and 2%, (n = 137, 130, 137) respectively. iARs were higher from index cases with vomiting, and amongst siblings. Disease ARs were higher when the index child was ,18 months and had vomiting, with household contact ,10 years and those sharing a room with the index case being more susceptible. We found no evidence of asymptomatic infections leading to disease transmission.
Conclusion: Transmission rates of rotavirus are high in households with an infected child, while background infections are rare. We have identified factors associated with transmission (vomiting/young age of index case) and susceptibility (young age/sharing a room/being a sibling of the index case). Vaccination may lead to indirect benefits by averting episodes or reducing symptoms in vaccinees
Higher Dimensional Cylindrical or Kasner Type Electrovacuum Solutions
We consider a D dimensional Kasner type diagonal spacetime where metric
functions depend only on a single coordinate and electromagnetic field shares
the symmetries of spacetime. These solutions can describe static cylindrical or
cosmological Einstein-Maxwell vacuum spacetimes. We mainly focus on
electrovacuum solutions and four different types of solutions are obtained in
which one of them has no four dimensional counterpart. We also consider the
properties of the general solution corresponding to the exterior field of a
charged line mass and discuss its several properties. Although it resembles the
same form with four dimensional one, there is a difference on the range of the
solutions for fixed signs of the parameters. General magnetic field vacuum
solution are also briefly discussed, which reduces to Bonnor-Melvin magnetic
universe for a special choice of the parameters. The Kasner forms of the
general solution are also presented for the cylindrical or cosmological cases.Comment: 16 pages, Revtex. Text and references are extended, Published versio
Scalar-field Pressure in Induced Gravity with Higgs Potential and Dark Matter
A model of induced gravity with a Higgs potential is investigated in detail
in view of the pressure components related to the scalar-field excitations. The
physical consequences emerging as an artifact due to the presence of these
pressure terms are analysed in terms of the constraints parting from energy
density, solar-relativistic effects and galactic dynamics along with the dark
matter halos.Comment: 26 pages, 3 figures, Minor revision, Published in JHE
Lessons to be learnt from Leishmania studies
Leishmaniasis is a disease caused by infection with the protozoan parasite Leishmania, which is responsible for three main types of disease: cutaneous leishmaniasis, visceral leishmaniasis and mucocutaneous leishmaniasis based to the site of infection for the particular species. This presents a major challenge to successful drug treatment, as a drug must not only reach antileishmanial concentrations in infected macrophages, the parasites' host cell, but also reach infected cells in locations specific to the type of disease. In this paper we discuss how studies using Leishmania have contributed to our knowledge on how drug delivery systems can be used to improve drug efficacy and delivery
Role of radiosynovectomy in the treatment of rheumatoid arthritis and hemophilic arthropathies
Radiosynovectomy is a novel method of treatment for several acute and chronic inflammatory joint disorders. A small amount of a beta-emitting radionuclide is injected into the affected joint delivering a radiation dose of 70 to 100 Gy to the synovia. The proliferative tissue is destroyed, secretion of fluid and accumulation of inflammation causing cellular compounds stops and the joint surfaces become fibrosed, providing long term symptom relief. The radionuclides are injected in colloidal form so that they remain in the synovium and are not transported by lymphatic vessels causing radiation exposure to other organs. Complete reduction of knee joint swelling has been seen in above 40% and pain relief in 88% of patients. Wrist, elbow, shoulder, ankle and hip joints showed significant improvement in 50-60% and restoration of normal function and long term pain relief has been achieved in about 70% of small finger joints. In hemophilic arthropathies complete cessation of bleeding in about 60% and improved mobility in 75% of patients has been reported
Development of Photonic Crystal Fiber Based Gas/ Chemical Sensors
The development of highly-sensitive and miniaturized sensors that capable of
real-time analytes detection is highly desirable. Nowadays, toxic or colorless
gas detection, air pollution monitoring, harmful chemical, pressure, strain,
humidity, and temperature sensors based on photonic crystal fiber (PCF) are
increasing rapidly due to its compact structure, fast response and efficient
light controlling capabilities. The propagating light through the PCF can be
controlled by varying the structural parameters and core-cladding materials, as
a result, evanescent field can be enhanced significantly which is the main
component of the PCF based gas/chemical sensors. The aim of this chapter is to
(1) describe the principle operation of PCF based gas/ chemical sensors, (2)
discuss the important PCF properties for optical sensors, (3) extensively
discuss the different types of microstructured optical fiber based gas/
chemical sensors, (4) study the effects of different core-cladding shapes, and
fiber background materials on sensing performance, and (5) highlight the main
challenges of PCF based gas/ chemical sensors and possible solutions
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