185 research outputs found
Micorwave Energy Aided Mineral Comminution
Mineral liberation during beneficiation is essentially through comminution. However, the fact that the major slice (up to 50 percent) in the pie for total energy requirements during beneficiation is occupied by comminution, dictates us to look into various possi-bilities to render comminution more energy-efficient.
In the early 1900s, efforts for reduction in the crushing and grinding energies based on the concept, 'thermally assisted liberation' (T A L) were made but could not be commercially exploited. With the advent of microwave energy and applications in different commercial operat-ions based on its property of heat generation in materials encouraged it in utilizing as an aid during comminution. Microwave energy heats individual phases in an ore matrix to different heat levels as per individual microwave absorption characteristics. Exposure to microwave energy over discrete time intervals prior to comminution results in development of micro fractures due to differential heating. Weakening of interspatial bonding in the ore matrix helps in lesser energy requirements. Numerous studies on microwave energy applications in the field of mineral processing and extractive metallurgy are under-taken in many parts of the world in recent years
Etfect of biostimulants on the growth and biomass of secondary nursery seedlings of cardamom
A nursery experiment was undertaken at the Indian Cardamom Research Institute, Myladumpara to understand the effectofbios tim ulants on the growth and biomass of secondary nursery cardamom s<ledlings. Five biostimulants at different concentrations were sprayed at 30- day intervals for a period of 120 days. The results indicated that biostimulants such as vipul (a tricontanol- containing commercial product), Ergostim (N-acetyl thiazolidne-4-carboxylic acid & folic acid - containing commercial product), pure folic acid, low levels ofsimazine and 2,4-D significantly increased the growth and dry matter production. The results suggest, that application ofbiostimulants not only reduces the nursery period but also helps in getting vigorous seedlings for better establishment in the field.
 
Salmonella Pathogenesis and Processing of Secreted Effectors by Caspase-3
The enteric pathogen Salmonella enterica serovar Typhimurium causes food poisoning resulting in gastroenteritis. The S. Typhimurium effector Salmonella invasion protein A (SipA) promotes gastroenteritis by functional motifs that trigger either mechanisms of inflammation or bacterial entry. During infection of intestinal epithelial cells, SipA was found to be responsible for the early activation of caspase-3, an enzyme that is required for SipA cleavage at a specific recognition motif that divided the protein into its two functional domains and activated SipA in a manner necessary for pathogenicity. Other caspase-3 cleavage sites identified in S. Typhimurium appeared to be restricted to secreted effector proteins, which indicates that this may be a general strategy used by this pathogen for processing of its secreted effectors
Sensitivity of Livestock Production to Climatic Variability Under Indian Drylands and Future Perspective
The livestock production system is considered equally sensitive to climate change as that of core agriculture system and at the same time livestock itself is also contributing to the phenomenon. The present paper attempts to analyze the sensitivity of livestock productivity in rainfed regions to climatic variability, significance of climate change with respect to Indian livestock and mitigation options and leverage points in such a scenario. The sensitively of livestock productivity was examined by using district level data of milk productivity of cow as well as buffalo for the year 1992 and 1997 for 100 districts which was regressed on important weather variables. The analysis shows that weather variables like rainfall and temperature do significantly influence the milk productivity of animals in rainfed regions. Increased climatic variability due to changing climate is likely to negatively influence the livestock productivity. Based on analysis and stakeholders consultation the paper suggests appropriate adaptation strategies particularly focusing on mitigating feed scarcity situations arising due to climatic variability
SIMULTANEOUS ESTIMATION OF DESLORATADINE AND MONTELUKAST IN BULK AND PHARMACEUTICAL FORMULATIONS BY RP-HPLC
A new, simple, precise, accurate and reproducible RP-HPLC method for Simultaneous estimation of Desloratadine and Montelukast in bulk and pharmaceutical formulations. Separation of Desloratadine and Montelukast was successfully achieved on a ECLEPSE XDB C8 (4.6 x 150mm, 5 mm, Make: Waters) or equivalent in an isocratic mode utilizing K2HPO4 buffer (pH: 8.6) Methanol (60:40%v/v) at a flow rate of 0.8 mL/min and elute was monitored at 261 nm, with a retention time of 2.485 and 3.800 minutes for Desloratadine and Montelukast. The method was validated and the response was found to be linear in the drug concentration range of 50 ”g/mL to 150 ”g/mL for Desloratadine and 50 ”g/mL to 150 ”g/mL for Montelukast. The LOD and LOQ for Desloratadine were found to be 2.759, 9.195 respectivly. The LOD and LOQ for Montelukast were found to be 2.9091, 9.6970 respectively. This method was found to be good percentage recovery for Desloratadine and Montelukast were found to be 100.00% and 100.00% respectively indicates that the proposed method is highly accurate. The specificity of the method shows good correlation between retention times of standard with the sample so, the method specifically determines the analyte in the sample without interference from excipients of tablet dosage forms. The method was extensively validated according to ICH guidelines for Linearity, Range, Accuacy, Precesion, Specificity and Robustness
Engineering a new loop-free shortest paths routing algorithm
International audienceWe present LFR (Loop Free Routing), a new loop-free distance vector routing algorithm, which is able to update the shortest paths of a distributed network with n nodes in fully dynamic scenarios. If Phi is the total number of nodes affected by a set of updates to the network, and phi is the maximum number of destinations for which a node is affected, then LFR requires O(Phi*Delta) messages and O(n + phi*Delta) space per node, where Delta is the maximum degree of the nodes of the network. We experimentally compare LFR with DUAL, one of the most popular loop-free distance vector algorithms, which is part of CISCO's EIGRP protocol and requires O(Phi*Delta) messages and Î(n*Delta) space per node. The experiments are based on both real-world and artificial instances and show that LFR is always the best choice in terms of memory require- ments, while in terms of messages LFR outperforms DUAL on real-world instances, whereas DUAL is the best choice on artificial instances
Catalysis in flow: Operando study of Pd catalyst speciation and leaching
A custom-made plug flow reactor was designed and constructed to examine the behaviour of Pd catalysts during Suzuki-Miyaura cross-coupling reactions. Spatial-temporal resolution of catalyst activation, deactivation and leaching processes can be obtained by single-pass experiments. Subsequent deployment of the flow reactor in a XAS beam line revealed speciation of Pd along the catalyst bed
Necrotrophism Is a Quorum-Sensing-Regulated Lifestyle in Bacillus thuringiensis
How pathogenic bacteria infect and kill their host is currently widely investigated. In comparison, the fate of pathogens after the death of their host receives less attention. We studied Bacillus thuringiensis (Bt) infection of an insect host, and show that NprR, a quorum sensor, is active after death of the insect and allows Bt to survive in the cadavers as vegetative cells. Transcriptomic analysis revealed that NprR regulates at least 41 genes, including many encoding degradative enzymes or proteins involved in the synthesis of a nonribosomal peptide named kurstakin. These degradative enzymes are essential in vitro to degrade several substrates and are specifically expressed after host death suggesting that Bt has an active necrotrophic lifestyle in the cadaver. We show that kurstakin is essential for Bt survival during necrotrophic development. It is required for swarming mobility and biofilm formation, presumably through a pore forming activity. A nprR deficient mutant does not develop necrotrophically and does not sporulate efficiently in the cadaver. We report that necrotrophism is a highly regulated mechanism essential for the Bt infectious cycle, contributing to spore spreading
Priprava i vrednovanje ĆĄumeÄih plutajuÄih tableta tizanidin hidroklorida
Tizanidine hydrochloride is an orally administered prokinetic agent that facilitates or restores motility throughout the length of the gastrointestinal tract. The objective of the present investigation was to develop effervescent floating matrix tablets of tizanidine hydrochloride for prolongation of gastric residence time in order to overcome its low bioavailability (3440 %) and short biological half life (4.2 h). Tablets were prepared by the direct compression method, using different viscosity grades of hydroxypropyl methylcellulose (HPMC K4M, K15M and K100M). Tablets were evaluated for various physical parameters and floating properties. Further, tablets were studied for in vitro drug release characteristics in 12 hours. Drug release from effervescent floating matrix tablets was sustained over 12 h with buoyant properties. DSC study revealed that there is no drug excipient interaction. Based on the release kinetics, all formulations best fitted the Higuchi, first-order model and non-Fickian as the mechanism of drug release. Optimized formulation (F9) was selected based on the similarity factor (f2) (74.2), dissolution efficiency at 2, 6 and 8 h, and t50 (5.4 h) and was used in radiographic studies by incorporating BaSO4. In vivo X-ray studies in human volunteers showed that the mean gastric residence time was 6.2 ± 0.2 h.Tizanidin hidroklorid je prokinetiÄki agens za peroralnu primjenu koji olakĆĄava ili obnavlja mobilnost kroz gastrointestinalni trakt. Cilj rada bio je razvoj ĆĄumeÄih plutajuÄih matriksnih tableta tizanidin hidroklorida za produljenje zadrĆŸavanja u ĆŸelucu u svrhu poboljĆĄanja niske bioraspoloĆŸivosti (3440 %) i produljenja vremena poluĆŸivota (4,2 h). Tablete su pripravljene metodom izravne kompresije, koristeÄi hidroksipropil metilcelulozu razliÄite viskoznosti (HPMCK4M, K15M i K100M). OdreÄeni su razliÄiti fizikalni parametri. OslobaÄanje ljekovite tvari in vitro bilo je polagano tijekom 12 sati, a tablete su imale svojstvo plutanja. Prema DSC ispitivanja nema interakcije s pomoÄnim tvarima. KinetiÄka ispitivanja pokazuju da oslobaÄanje iz svih pripravaka slijedi Higuchijev model, kinetiku prvog reda i ne-Fickov zakon. Na temelju faktora sliÄnosti (f2) (74,2), oslobaÄanja ljekovite tvari nakon 2, 6 i 8 h, te vremena poluĆŸivota t50 (5,4 h) izabrana je optimirana formulacija (F9) i upotrebljena u radiografiÄkim ispitivanjima koja ukljuÄuju BaSO4. In vivo ispitivanja rendgenskim zrakama na dobrovoljcima pokazala su da je srednje vrijeme zadrĆŸavanja u ĆŸelucu bilo 6,2 ± 0,2 h
Downregulation of uPAR and Cathepsin B Induces Apoptosis via Regulation of Bcl-2 and Bax and Inhibition of the PI3K/Akt Pathway in Gliomas
Glioma is the most commonly diagnosed primary brain tumor and is characterized by invasive and infiltrative behavior. uPAR and cathepsin B are known to be overexpressed in high-grade gliomas and are strongly correlated with invasive cancer phenotypes.In the present study, we observed that simultaneous downregulation of uPAR and cathepsin B induces upregulation of some pro-apoptotic genes and suppression of anti-apoptotic genes in human glioma cells. uPAR and cathepsin B (pCU)-downregulated cells exhibited decreases in the Bcl-2/Bax ratio and initiated the collapse of mitochondrial membrane potential. We also observed that the broad caspase inhibitor, Z-Asp-2, 6-dichlorobenzoylmethylketone rescued pCU-induced apoptosis in U251 cells but not in 5310 cells. Immunoblot analysis of caspase-9 immunoprecipitates for Apaf-1 showed that uPAR and cathepsin B knockdown activated apoptosome complex formation in U251 cells. Downregulation of uPAR and cathepsin B also retarded nuclear translocation and interfered with DNA binding activity of CREB in both U251 and 5310 cells. Further western blotting analysis demonstrated that downregulation of uPAR and cathepsin B significantly decreased expression of the signaling molecules p-PDGFR-ÎČ, p-PI3K and p-Akt. An increase in the number of TUNEL-positive cells, increased Bax expression, and decreased Bcl-2 expression in nude mice brain tumor sections and brain tissue lysates confirm our in vitro results.In conclusion, RNAi-mediated downregulation of uPAR and cathepsin B initiates caspase-dependent mitochondrial apoptosis in U251 cells and caspase-independent mitochondrial apoptosis in 5310 cells. Thus, targeting uPAR and cathepsin B-mediated signaling using siRNA may serve as a novel therapeutic strategy for the treatment of gliomas
- âŠ