48,793 research outputs found
A Comparative study on Ferro-fluid Lubricated Porous Journal Bearing
This research considered hydrodynamic theory on ferro-fluid flow models such as R. E. Rosensweig model and Jenkins model for axially undefined journal bearing with porous attached at the inner surface (i.e. on the journal). In this study, the variable external magnetic field is assumed. The expressions of (non-dimensional) pressure and load-carrying capacity are obtained. The values of load capacity for both models are calculated for various parameters like porous thickness, slip velocity, squeeze velocity, permeability, and eccentricity. Also, calculated load capacity by cons idering porous structure models like the globular sphere model and capillary fissures model. Based on the obtained results, the globular sphere model gives much better performance for load capacity rather than the capillary fissures model. From the study, it is suggested that to design the journal bearing, globular sphere model of porous structure should be preferred over the capillary fissures model. Also, for the better performance of the journal bearing, the choice of fluid-flow model depends on the values of parameters
Changes in murine anorectum signaling across the life course
Background: Increasing age is associated with an increase in the incidence of chronic constipation and fecal impaction. The contribution of the natural aging process to these conditions is not fully understood. This study examined the effects of increasing age on the function of the murine anorectum.Methods: The effects of increasing age on cholinergic, nitrergic, and purinergic signaling pathways in the murine anorectum were examined using classical organ bath assays to examine tissue function and electrochemical sensing to determine age‐related changes in nitric oxide and acetylcholine release.Key Results: Nitrergic relaxation increased between 3 and 6 months, peaked at 12 months and declined in the 18 and 24 months groups. These changes were in part explained by an age‐related decrease in nitric oxide (NO) release. Cholinergic signaling was maintained with age by an increase in acetylcholine (ACh) release and a compensatory decrease in cholinesterase activity. Age‐related changes in purinergic relaxation were qualitatively similar to nitrergic relaxation although the relaxations were much smaller. Increasing age did not alter the response of the anorectum smooth muscle to exogenously applied ACh, ATP, sodium nitroprusside or KCl. Similarly, there was no change in basal tension developed by the anorectum.Conclusions and Inferences: The decrease in nitrergic signaling with increasing age may contribute to the age‐related fecal impaction and constipation previously described in this model by partially obstructing defecation
MULTIPLE UNIT PELLET SYSTEM (MUPS) BASED FAST DISINTEGRATING DELAYED-RELEASE TABLETS FOR PANTOPRAZOLE DELIVERY
Objective: The rationale for the study was to develop multiple unit pellet system (MUPS) of delayed release pantoprazole with desired physical properties and unaltered drug release profile from pellets even after compression into a fast disintegrating tablet.Methods: In the presented study, delayed release pellets of pantoprazole were developed by two methods, i.e. extrusion-spheronization and drug layering techniques, coated using enteric polymer and subsequently compressed in to tablet. In drug layering technique, pantoprazole was loaded on Celphere®102 (microcrystalline cellulose spheres) as well as on Suglet® (sugar spheres) in fluid bed processor. Acid resistant polymer Eudragit ND 30D was subsequently coated on each type of drug loaded pellets. Suitable tableting excipients were prepared such as soft pellets, Ceolus® (fibrous grade of microcrystalline cellulose) granules, Ludipress® (compressible lactose composition), Avicel® PH 200 and different combination of them. Various factors like property of pellets to be compressed, coating level, the composition of tableting excipient and ratio of drug-loaded pellets to tableting excipients were identified and optimized.Results: MUPS with delayed releasing pellets of pantoprazole proved to provide sufficient hardness, rapid disintegration property, and unaltered release profile after compression. Delayed release pantoprazole pellets prepared by drug layering on celphere® 102 followed by coating with Eudragit® NE 30D showed better compressibility to withstand the drug release properties. The combination of Ceolus® granules and Ludipress (in 1:1 ratio) was found to be suitable tableting excipient that helped compression of pellets without rupturing polymeric coat. Pellets to excipients ratio at 1:3 was found optimum.Conclusion: Compaction behaviour of pantoprazole delayed-release pellets without loss of original delayed release profile was achieved by formulating as MUPS based tablet of pantoprazole delayed release pellets using celephere® 102 was developed which was found suitable for desired release profile and physical properties
Overview of pulsed electric field (pef) preservation on food products
The rise in consumer demand for nutritious food options combined with a desire for a more natural taste has prompted the creation of novel gentle food preservation processes as alternatives to traditional methods like heat treatment. New Methods like high hydrostatic pressure and pulsed electric fields (PEFs), have emerged as no thermal pasteurization methods. These methods aim to effectively reduce microbial content while maintaining the quality of the food product. Pulsed electric field processing is particularly suitable for decontaminating heat-sensitive foods. Furthermore, it presents no environmental risks and has shown no indications of toxicity [1]
Broadband study of blazar 1ES 1959+650 during flaring state in 2016
Aim : The nearby TeV blazar 1ES 1959+650 (z=0.047) was reported to be in
flaring state during June - July 2016 by Fermi-LAT, FACT, MAGIC and VERITAS
collaborations. We studied the spectral energy distributions (SEDs) in
different states of the flare during MJD 57530 - 57589 using simultaneous
multiwaveband data to understand the possible broadband emission scenario
during the flare. Methods : The UV/optical and X-ray data from UVOT and XRT
respectively on board Swift and high energy -ray data from Fermi-LAT
are used to generate multiwaveband lightcurves as well as to obtain high flux
states and quiescent state SEDs. The correlation and lag between different
energy bands is quantified using discrete correlation function. The synchrotron
self Compton (SSC) model was used to reproduce the observed SEDs during flaring
and quiescent states of the source. Results : A decent correlation is seen
between X-ray and high energy -ray fluxes. The spectral hardening with
increase in the flux is seen in X-ray band. The powerlaw index vs flux plot in
-ray band indicates the different emission regions for 0.1 - 3 GeV and
3-300 GeV energy photons. Two zone SSC model satisfactorily fits the observed
broadband SEDs. The inner zone is mainly responsible for producing synchrotron
peak and high energy -ray part of the SED in all states. The second
zone is mainly required to produce less variable optical/UV and low energy
-ray emission. Conclusions : Conventional single zone SSC model does
not satisfactorily explain broadband emission during observation period
considered. There is an indication of two emission zones in the jet which are
responsible for producing broadband emission from optical to high energy
-rays.Comment: 11 pages, 12 figures, Accepted in A&
Spirulina: nutritional and therapeutic review
The current environmental conditions deteriorations, mental and physical stress, changes in the diet have been serious risk factors for the humans, increased the death rate and civilization diseases. These are the obvious reasons
why new progressive trends are being extensively developed in modern medicine, pharmacology and biotechnology and more effective harmless medicaments are being sought for to treat and prevent various diseases. One of the trends in biotechnology is associated with Blue green microalgae Spirulina platensis which have been widely employed as food and feed additives in agriculture, food industry, pharmaceuticals, perfume making, medicine and science [1]
Natural remedies to combat aberrant hallmark signatures including altered glycosylation in oral carcinoma
Background: Tobacco associated oral cancers remain a major concern in India with higher incidence and mortality making it an Indian-centric burning issue. To combat this dreadful disease, we investigated effects of certain natural compounds on the hallmark signatures including glycosylation transcripts levels in oral carcinoma.
Methods: The tongue carcinoma cells- SAS cells were treated with tobacco compounds, natural compounds and Cisplatin. RNA was isolated from the cells and converted to cDNA. RT-qPCR was performed to evaluate expression levels of various genes.
Results: The treatment of tobacco compounds resulted in similar pattern of altered makers (ST3GAL1, NEU3, FUT5, FUT6, MMP2, BCL2) as observed in tobacco habituated patients. The treatment of Curcumin resulted in down regulation of FUT8 and MMP2 which are known to have a significant association with disease progression and metastasis. Furthermore, Curcumin treatment also resulted in up regulation of the good prognostic glycosylation transcript marker i.e. FUT3 showing its protective effect against the tumor invasion and metastasis. Butein treatment resulted in the down regulation of the worst prognostic indicators i.e. FUT8 and MMP2 in a dose dependent manner. Piceatannol treatment showed better protective effects via down regulation of the markers related to the aggressive disease progression (ST3GAL2, FUT5, FUT8, MMP2, VEGFC).
Conclusion: The study provides novel approach of targeting aberrant hallmark signatures including glycosylation with natural compounds which may open the possibility of promising therapeutic strategies using natural compounds alone or in combination with other conventional therapies to alleviate the present scenario of this dreadful disease in India
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