155 research outputs found
Performance Trade-offs in Layouts For Relief Centers
At a disaster affected region, relief centers distribute critical supplies and aid to the affected victims. Unlike traditional distribution centers, relief centers experience significant ‘crowd effects’ due to the sudden influx of victims in a confined space. Using knowledge from studies on pedestrian traffic flow, specialized state dependent queuing models are developed to model the flow of victims along the walkways setup at a relief center. The underlying queuing network model is analyzed to derive expressions for the average times that victims experience before they receive the service at the relief center. The research shows that crowd density effects lead to significant increase in congestion and queuing delays underscoring the importance of developing specialized queuing models that assess the impact of congestion effects on alternative layouts of relief centers
Enhanced photoelectrochemical response of 1D TiO₂ by atmospheric pressure plasma surface modification
In this paper we demonstrate the use of atmospheric pressure plasma jet (APPJ) to functionalize the surface of hydrothermally synthesized vertically aligned TiO2 nanorods (TNRs) for photo electrochemical (PEC) application. The TNRs functionalized with the atmospheric pressure He-plasma showed relatively higher crystallinity, improved light absorption, and change in the morphology with additional surface area, leading to an enhanced photocurrent density than that of the untreated. Achieving the PEC performance on par with the best in the literature, this APPJ treatment is shown to be a promising technique to obtain better functionality with TNR kind of materials and many other nano-micro systems for various applications such as PEC hydrogen generation
ANALYTICAL METHOD DEVELOPMENT AND VALIDATION FOR DIPYRIDAMOLE
A sensitive, specific, precise and cost effective High Performance Liquid Chromatographic method of analysis for dipyridamole in presence of its degradation products is developed and validated. The method employed Targa C8 column i.e., (250 X 4.6 mm 5 μm particle size) column as stationary phase. The mobile phase consists of acetonitrile and pH3.0 buffer in the ratio of 35:65 %. It is pumped through the chromatographic system at a flow rate of 1.2 ml/min. The UV detector is operated at 282 nm. This system was found to give good resolution between dipyridamole and its degradation products. Method was validated as per ICH guideline
PREPARATION, SOLID STATE CHARACTERISATION OF PACLITAXEL AND NARINGEN COCRYSTALS WITH IMPROVED SOLUBILITY
Objective: The objective of the present study is to prepare a better form of paclitaxel cocrystal with improved solubility. Paclitaxel (PTX) is a class-4 drug; this drug has low aqueous solubility and high affinity for P-gp. Available formulation are IV based and using our research work with advantages of co-crystal technology towards the enhancement of paclitaxel solubility and thereby its bioavailability (1) and also to improve the patient compliance.
Methods: Naringen was selected based on their chemical nature and its ability to inhibit P-gp, solvent assisted grinding method used to prepare the cocrystals, and prepared cocrystals were subjected to solid state characterization to determine the crystal structure of the cocrystals, as this can provide significant new insights into how the drug and coformer interact, and thereby provide an excellent crystal engineering guide to new cocrystals, potentially with improved properties. Instruments like Fourier transform infrared spectroscopy(FTIR), differential scanning calorimetry, X-ray powder diffraction will be used to determine their stability and any phase transformations (including decomposition) which they might undergo as a function of temperature.
Results: Principle involved in the formation of cocrystal is hydrogen bonding between C=O and N-H group of drug and COOH groups of coformers, which is confirmed by FTIR data and DSC experiments were carried out to study the melting point and heat of enthalpy of the cocrystals. Results clearly shows that the melting point of the cocrystals was increased which confirms the formation of cocrystals. The drug and formation of cocrystals are explained by the X-ray powder diffraction patterns. The PXRD patterns of the pure drug showed sharp, well-defined peaks(spectrum attached) and cocrystals PXRD patterns shows that there is a significant difference in the entire diffraction pattern, changes in peak locations with respect to pure drug indicates a change in the arrangement of molecules, hence confirms the development of new crystalline phase.
Conclusion: The results obtained from the above experiments clearly shows the formation of cocrystals with improved solubility
Organ-specific adaptive signaling pathway activation in metastatic breast cancer cells
Breast cancer metastasizes to bone, visceral organs, and/or brain depending on the subtype, which may involve activation of a host organ-specific signaling network in metastatic cells. To test this possibility, we determined gene expression patterns in MDA-MB-231 cells and its mammary fat pad tumor (TMD-231), lung-metastasis (LMD-231), bone-metastasis (BMD-231), adrenal-metastasis (ADMD-231) and brain-metastasis (231-BR) variants. When gene expression between metastases was compared, 231-BR cells showed the highest gene expression difference followed by ADMD-231, LMD-231, and BMD-231 cells. Neuronal transmembrane proteins SLITRK2, TMEM47, and LYPD1 were specifically overexpressed in 231-BR cells. Pathway-analyses revealed activation of signaling networks that would enable cancer cells to adapt to organs of metastasis such as drug detoxification/oxidative stress response/semaphorin neuronal pathway in 231-BR, Notch/orphan nuclear receptor signals involved in steroidogenesis in ADMD-231, acute phase response in LMD-231, and cytokine/hematopoietic stem cell signaling in BMD-231 cells. Only NF-κB signaling pathway activation was common to all except BMD-231 cells. We confirmed NF-κB activation in 231-BR and in a brain metastatic variant of 4T1 cells (4T1-BR). Dimethylaminoparthenolide inhibited NF-κB activity, LYPD1 expression, and proliferation of 231-BR and 4T1-BR cells. Thus, transcriptome change enabling adaptation to host organs is likely one of the mechanisms associated with organ-specific metastasis and could potentially be targeted therapeutically
Current status of viral diseases affecting black pepper and cardamom
Black pepper and cardamom are the important spice crops grown in India and other countries. Viruses are one of the major yield limiting factors in both these spice crops. Viral diseases spread at a faster rate in these spices, as they are vegetatively propagated. Lack of sensitive detection methods has led to the widespread distribution of viral diseases in all black pepper and cardamom growing regions. The viruses infecting these two spice crops have now been identified; characterized and sensitive diagnostics have been developed. Integration of various approaches like use of resistant varieties, virus-free planting materials, vector control and cultural methods are required for the management of viral diseases. Rejuvenation of viral disease affected black pepper plantations through proper soil and plant health management were proved to be successful. The present review deals with characterization, diagnosis and management of viral diseases affecting black pepper and cardamom
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The role of potential vorticity anomalies in the Somali Jet on Indian summer monsoon intraseasonal variability
The climate of the Indian subcontinent is dominated by rainfall arising from the Indian summer monsoon (ISM) during the summer season (June to September). Intraseasonal variability during the monsoon is characterized by periods of heavy rainfall interspersed by drier periods, known as active and break events respectively. Understanding and predicting such events is of vital importance for forecasting human impacts such as water resources. The Somali Jet is a key regional feature of this circulation. In the present study, we find that the spatial structure of Somali Jet potential vorticity (PV) anomalies varies considerably during active and break periods. Analysis of these anomalies shows a mechanism whereby sea surface temperature (SST) anomalies propagate north/northwestwards through the Arabian Sea, caused by a positive feedback loop joining anomalies in SST, convection, modification of PV by diabatic heating and mixing in the atmospheric boundary layer, wind stress curl, and upwelling processes. The feedback mechanism is consistent with observed coupled ocean-atmosphere system variability timescales of approximately 20 days. This research suggests that better understanding and prediction of monsoon subseasonal variability in the South Asian monsoon may be gained by analysis of the day-to-day dynamical evolution of PV in the Somali Jet
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The interaction of moist convection and mid-level dry air in the advance of the onset of the Indian monsoon
The advance of the onset of the Indian monsoon is here explained in terms of a balance between the low-level monsoon flow and an over-running intrusion of mid-tropospheric dry air. The monsoon advances, over a period of about 6 weeks, from the south of the country to the northwest. Given that the low-level monsoon winds are westerly or southwesterly, and the midlevel winds northwesterly, the monsoon onset propagates upwind relative to midlevel flow, and perpendicular to the low-level flow, and is not directly caused by moisture flux toward the northwest. Lacking a conceptual model for the advance means that it has been hard to understand and correct known biases in weather and climate prediction models.
The mid-level northwesterlies form a wedge of dry air that is deep in the far northwest of India and over-runs the monsoon flow. The dry layer is moistened from below by shallow cumulus and congestus clouds, so that the profile becomes much closer to moist adiabatic, and the dry layer is much shallower in the vertical, toward the southeast of India. The profiles associated with this dry air show how the most favourable environment for deep convection occurs in the south, and onset occurs here first.
As the onset advances across India, the advection of moisture from the Arabian Sea becomes stronger, and the mid-level dry air is increasingly moistened from below. This increased moistening makes the wedge of dry air shallower throughout its horizontal extent, and forces the northern limit of moist convection to move toward the northwest. Wetting of the land surface by rainfall will further reinforce the north-westward progression, by sustaining the supply of boundary layer moisture and shallow cumulus. The local advance of the monsoon onset is coincident with weakening of the mid-level northwesterlies, and therefore weakened mid-level dry advection
Spintronics: Fundamentals and applications
Spintronics, or spin electronics, involves the study of active control and
manipulation of spin degrees of freedom in solid-state systems. This article
reviews the current status of this subject, including both recent advances and
well-established results. The primary focus is on the basic physical principles
underlying the generation of carrier spin polarization, spin dynamics, and
spin-polarized transport in semiconductors and metals. Spin transport differs
from charge transport in that spin is a nonconserved quantity in solids due to
spin-orbit and hyperfine coupling. The authors discuss in detail spin
decoherence mechanisms in metals and semiconductors. Various theories of spin
injection and spin-polarized transport are applied to hybrid structures
relevant to spin-based devices and fundamental studies of materials properties.
Experimental work is reviewed with the emphasis on projected applications, in
which external electric and magnetic fields and illumination by light will be
used to control spin and charge dynamics to create new functionalities not
feasible or ineffective with conventional electronics.Comment: invited review, 36 figures, 900+ references; minor stylistic changes
from the published versio
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