851 research outputs found
Effect of Hydrogen on Pristine Amorphous V2O5 Thin Film
Sequentially deposited layer by layer up to five vanadium oxide film is deposited on glass and silica substrates at 300 k by vacuum thermal evaporation technique. The deposited samples subjected to reduction process in the preparation situe by hydrogen gas at 473k for 10 minutes and 573 k for 10, 20 minutes. The XRD investigation of the samples demonstrates that the pristine sample is amorphous while those reduced are crystalline. The existed phases in virgin samples are educated by Raman spectroscopy which indicates the single V2O5 phase. The different phases in the reduced sample are identified by analyzing their XRD patterns. The electrical resistance of the reduced samples is measured as a function of temperature during heating and cooling cycles. The transition temperature from semiconducting to metal state is defined by the derivative of dR/d
CaracterizaciĂłn de aceite de semilla de girasol extraĂdo enzimáticamente asĂ como de los residuos proteĂnicos
Sunflower seed oil was enzymatically extracted with six different enzymes: cellulase, hemicellulase, animal proteinase, acid proteinase, pectinase and pectinex under the following conditions: substrate concentration in phosphate buffer (0.5M, pH 5) 30%, enzyme concentration 2% (E/S), temperature 50°C and time 3 hours. The obtained oils were analyzed for physicochemical properties and fatty acid profiles. The protein residues were analyzed for amino acid compositions.
The results showed that the enzymatic extraction with cellulase or hemicellulase could maintain good oil quality of the extracted oils as their levels of linoleic and oleic acids recorded similar values to those of the control oil extracted with organic solvents. Also the level of iodine value was in the same level of control. On the other hand, the use of proteases in the enzymatic extraction of sunflower seed oil caused some reductions in the levels of the unsaturated fatty acids as well as the iodine value. The pectinases showed a similar trend to that of the proteinase with the least recovery of linoleic acid among the different oils under study.
Similarly, the use of cellulases did not change the amino acid composition of the protein residue as compared to the control, in the contrary to the extraction with the proteinases which caused reduction of some amino acids from the protein residues especially lysine, leucine, iso-leucine, alanine, arginine and aspartic. In that respect the use of pectinases behaved similar to cellulases.Aceite de semilla de girasol fue extraĂdo enzimáticamente con seis enzimas diferentes: celulasa, hemicelulasa, proteinasa animal, proteinase acida, pectinasa y pectinex bajo las condiciones siguientes: concentraciĂłn de sustrato en tampĂłn fosfato (0,5M, pH 5) 30%, concentraciĂłn enzimática 2% (E/S), temperatura 50°C y tiempo 3 horas. Los aceites obtenidos fueron analizados por sus propiedades fisicoquĂmicas y perfiles de ácidos grasos.
Los residuos proteĂnicos fueron analizados por sus composiciones en aminoácidos. Los resultados mostraron que la extracciĂłn enzimática con celulasa o hemicelulasa podĂan proporcionar buena calidad en los aceites, ya que sus niveles de ácidos linoleico y oleico registraron valores similares a los del aceite control extraĂdo con disolventes orgánicos. TambiĂ©n el valor de Ăndice de iodo fue similar al del control. Por otro lado, el uso de proteasas en la extracciĂłn enzimática de aceite de semilla de girasol causĂł algunas reducciones en los niveles de ácidos grasos insaturados, asĂ como en el Ăndice de iodo. Las pectinasas mostraron una tendencia similar a la de las proteinases con la menor obtenciĂłn de ácido linoleico entre los diferentes aceites en estudio.
Del mismo modo, el uso de celulasas no cambiĂł la composiciĂłn de aminoácidos del residuo proteĂnico comparado con el control, por el contrario la extracciĂłn con proteinasas causĂł una disminuciĂłn de algunos aminoácidos, especialmente lisina, leucina, isoleucina, alanina, arginina y aspártico. A este respecto, el uso de pectinasa se portĂł de manera análoga al de celulasas
Bone Mineral Density Changes in Patients with Recent-Onset Rheumatoid Arthritis
Background Osteoporosis and related fragility fractures are one of the most common complications seen in patients with rheumatoid arthritis (RA) and dramatically affect quality of life. Objective To evaluate changes in bone mineral density in patients with recent onset rheumatoid arthritis (< 1 year) and its correlation if any with a modified DAS-28 score and simple erosion narrowing score (SENS). Methods This study included 30 patients with recent-onset rheumatoid arthritis fulfilling the new American College of Rheumatology/European League Against Rheumatism diagnostic criteria for rheumatoid arthritis and 20 healthy volunteers as controls. All were subjected to a complete blood count, erythrocyte sedimentation rate, C-reactive protein, liver function tests, renal function tests, rheumatoid factor, and plain x-rays of the hands and feet. Dual-energy x-ray absorptiometry DEXA was used to measure bone mineral density (BMD) of the left proximal femur, lumbar spine (L1–L4), and lower distal radius at the time of recruitment. Results In the RA patients, 13.3% had osteoporosis, 50% had osteopenia, and 36.7% had normal BMD. The most common site of osteoporosis was the lumbar spine (four patients, 13.3%) followed by the femur (two patients, 6.6%), and forearm (only one patient, 3.3%). There was a significantly higher percentage of osteoporosis among RA males than females and the difference was statistically significant ( P = 0.009). Osteoporosis was more common in patients treated with corticosteroids and disease modifying antirheumatic drugs (DMARDs) than in patients treated with only nonsteroidal anti-inflammatory drugs ( P = 0.004). Higher disease activity (DAS-28) was found in RA patients with osteoporosis compared to RA patients with normal BMD or osteopenia, but the difference was not statistically significant. Osteoporotic RA patients were found to have a higher SENS score for radiological damage than nonosteoporotic ones. Conclusion BMD changes do occur in patients with early RA, and are not necessarily correlated with disease activity (DAS-28). However, a significant negative correlation was found between BMD and the score of radiological damage (SENS). Dual energy x-ray absorptiometry is an important investigation to assess BMD in early RA patients
A new cell primo-culture method for freshwater benthic diatom communities
A new cell primo-culture method was developed for the benthic diatom community isolated from biofilm sampled in rivers. The approach comprised three steps: (1) scraping biofilm from river pebbles, (2) diatom isolation
from biofilm, and (3) diatom community culture. With a view to designing a method able to stimulate the growth of diatoms, to limit the development of other microorganisms, and to maintain in culture a community similar to the original natural one, different factors were tested in step 3:
cell culture medium (Chu No 10 vs Freshwater “WC” medium modified), cell culture vessel, and time of culture. The results showed that using Chu No 10 medium in an Erlenmeyer flask for cell culture was the optimal method,
producing enough biomass for ecotoxicological tests as well as minimising development of other microorganisms. After 96 h of culture, communities differed from the original communities sampled in the two rivers studied.
Species tolerant of eutrophic or saprobic conditions were favoured during culture. This method of diatom community culture affords the opportunity to assess, in vitro, the effects of different chemicals or effluents (water samples andindustrial effluents) on diatom communities, as well as on diatom cells, from a wide range of perspectives
Temperature and Field Dependence of the Energy Gap of MgB2/Pb planar junction
We have constructed MgB2/Pb planar junctions for both temperature and field
dependence studies. Our results show that the small gap is a true bulk property
of MgB2 superconductor, not due to surface effects. The temperature dependence
of the energy gap manifests a nearly BCS-like behavior. Analysis of the effect
of magnetic field on junctions suggests that the energy gap of MgB2 depends
non-linearly on the magnetic field. Moreover, MgB2 has an upper critical field
of 15 T, in agreement with some reported Hc2 from transport measurements.Comment: 5 pages, 5 figures. Submitted to Phys. Rev.
Schistosomiasis and Urinary Bladder Cancer in North Western Tanzania: A Retrospective Review of 185 Patients.
Worldwide, cancers of the urinary bladder are well known to be associated with environmental chemical carcinogens such as smoking and occupational exposure to polycyclic aromatic hydrocarbons. These cancers are typically transitional cell carcinoma (urothelial carcinoma). In areas where schistosomiasis is endemic there is a high incidence of squamous cell carcinoma of the urinary bladder. Schistosomiasis causes chronic granulomatous cystitis leading to squamous metaplasia of transitional epithelium, and subsequently development of squamous cell carcinoma. The western part of Tanzania on the shores of Lake Victoria is such an endemic area. This study was done to document the burden of urinary bladder cancer associated with schistosomiasis in this region. This was a descriptive retrospective study of histologically confirmed cases of urinary bladder cancer seen at the Department of Pathology Bugando Medical Centre (BMC) over a period of 10 years. Data were retrieved from the records of the Departments of Pathology, Medical Records and Surgery. Data were analyzed by the use of contingency tables. A total of 185 patients were diagnosed with cancer of the urinary bladder during the study period, where as 90 (48.6%) were males and 95 (51.4) were females. The mean age at diagnosis was 54.3 years. Squamous cell carcinoma was the most frequent histological type (55.1%), followed by conventional transitional cell carcinoma (40.5%). Eighty three of all cancer cases (44.9%) were found to have schistosomal eggs. Schistosomiasis was commonly associated with squamous cancers compared to non squamous cancers. Most of the cancers associated with schistosomiasis had invaded the muscularis propria of the urinary bladder at the time of diagnosis (p<0.001) and such cancers were frequent below 50 years of age with a significant statistical difference (p<0.001). Poorly differentiated tumors were more frequent in females than males with a significant statistical difference (p=0.006). The majority of urinary bladder cancers seen in the Lake Region were squamous cell carcinoma associated with schistosomiasis. These cancers showed an aggressive behavior and were commonly seen in the younger age groups. Effective control of schistosomiasis in this region should significantly reduce the burden of urinary bladder cancer
Cell arrest and cell death in mammalian preimplantation development
The causes, modes, biological role and prospective significance of cell death in preimplantation development in humans and other mammals are still poorly understood. Early bovine embryos represent a very attractive experimental model for the investigation of this fundamental and important issue.
To obtain reference data on the temporal and spatial occurrence of cell death in early bovine embryogenesis, three-dimensionally preserved embryos of different ages and stages of development up to hatched blastocysts were examined in toto by confocal laser scanning microscopy. In parallel, transcript abundance profiles for selected apoptosis-related genes were analyzed by real-time reverse transcriptase-polymerase chain reaction. Our study documents that in vitro as well as in vivo, the first four cleavage cycles are prone to a high failure rate including different types of permanent cell cycle arrest and subsequent non-apoptotic blastomere death. In vitro produced and in vivo derived blastocysts showed a significant incidence of cell death in the inner cell mass (ICM), but only in part with morphological features of apoptosis. Importantly, transcripts for CASP3, CASP9, CASP8 and FAS/FASLG were not detectable or found at very low abundances.
In vitro and in vivo, errors and failures of the first and the next three cleavage divisions frequently cause immediate embryo death or lead to aberrant subsequent development, and are the main source of developmental heterogeneity. A substantial occurrence of cell death in the ICM even in fast developing blastocysts strongly suggests a regular developmentally controlled elimination of cells, while the nature and mechanisms of ICM cell death are unclear. Morphological findings as well as transcript levels measured for important apoptosis-related genes are in conflict with the view that classical caspase-mediated apoptosis is the major cause of cell death in early bovine development
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