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41.
A mild chitosan/calcium alginate microencapsulation process, as applied to encapsulation of biological macromolecules such as albumin and insulin, was investigated. The microcapsules were derived by adding dropwise a protein-containing sodium alginate mixture into a chitosan–CaCl2 system. The beads containing a high concentration of entrapped bovine serum albumin (BSA) as more than 70% of the initial concentration were achieved via varying chitosan coat. It was observed that approximately 70% of the content is being released into Tris-HCl buffer, pH 7.4 within 24 h and no significant release of BSA was observed during treatment with 0.1M HCl pH 1.2 for 4 h. But the acid-treated beads had released almost all the entrapped protein into Tris-HCl pH 7.4 media within 24 h. Instead of BSA, the insulin preload was found to be very low in the chitosan/calcium alginate system; the release characteristics were similar to that of BSA. From scanning electron microscopic studies, it appears that the chitosan modifies the alginate microspheres and subsequently the protein loading. The results indicate the possibility of modifying the formulation in order to obtain the desired controlled release of bioactive peptides (insulin), for a convenient gastrointestinal tract delivery system. © 1996 John Wiley & Sons, Inc. 相似文献
42.
K.M. Gangotri Om Prakash Regar Chhagan Lal Prashant Kalla Kishna Ram Genwa Rajni Meena 《国际能源研究杂志》1996,20(7):581-585
Photogalvanic effects were studied in a photogalvanic cell containing toluidine blue, glucose and tergitol-7 as a photosensitizer, reductant and surfactant, respectively. The photocurrent and photopotential generated by this system were 70 μA and 315 mV, respectively. The effects of different parameters on the electrical output of the cell were observed. Current/voltage characteristics of the cell have also been studied, and a mechanism has been proposed for the generation of photocurrent in photogalvanic cell. 相似文献
43.
Pavlína Janovsk Emmanuel Normant Hari Miskin Vítzslav Bryja 《International journal of molecular sciences》2020,21(23)
The casein kinase 1 enzymes (CK1) form a family of serine/threonine kinases with seven CK1 isoforms identified in humans. The most important substrates of CK1 kinases are proteins that act in the regulatory nodes essential for tumorigenesis of hematological malignancies. Among those, the most important are the functions of CK1s in the regulation of Wnt pathways, cell proliferation, apoptosis and autophagy. In this review we summarize the recent developments in the understanding of biology and therapeutic potential of the inhibition of CK1 isoforms in the pathogenesis of chronic lymphocytic leukemia (CLL), other non-Hodgkin lymphomas (NHL), myelodysplastic syndrome (MDS), acute myeloid leukemia (AML) and multiple myeloma (MM). CK1δ/ε inhibitors block CLL development in preclinical models via inhibition of WNT-5A/ROR1-driven non-canonical Wnt pathway. While no selective CK1 inhibitors have reached clinical stage to date, one dual PI3Kδ and CK1ε inhibitor, umbralisib, is currently in clinical trials for CLL and NHL patients. In MDS, AML and MM, inhibition of CK1α, acting via activation of p53 pathway, showed promising preclinical activities and the first CK1α inhibitor has now entered the clinical trials. 相似文献
44.
The hydrogenation/dehydrogenation catalytic activity of minerals commonly present in coal was investigated. The extent of reaction undergone by the model hydrogen-transfer system tetralin/1,2-dihydronaphthalene/naphthalene at 400 °C in the presence of these minerals was used to measure the catalytic activity. For the four most active minerals, the order of catalytic activity per gram of mineral, for a given range of particle size, is limonites > pyrites > diaspore > magnetites. The pure chemical analog of the limonites, Fe2O3, was found to have catalytic activity similar to that of the limonites. Heating the minerals at 400 °C before running the reaction was found to decrease these catalytic activities, despite the surface-area increases resulting from the annealing process. The catalytic activity per unit area of mineral was determined and used as an index of the catalytic activity of the reactive sites for these heterogeneous systems. The order of decreasing site catalytic activity for the more active minerals is pyrites > magnetites > diaspore > limonites. The observed mineral/ chemical compound catalytic activities indicate that the more reactive mineral hydrogenation/ dehydrogenation catalytic sites are composed of iron compounds. 相似文献
45.
Satish Kumar Vemuri Satyajit Halder Rajkiran Reddy Banala Hari Krishnreddy Rachamalla Vijaya Madhuri Devraj Chandra Shekar Mallarpu Uttam Kumar Neerudu Ravikiran Bodlapati Sudip Mukherjee Subbaiah Goli Peda Venkata Gurava Reddy Annapareddy Venkata Malarvilli Thakkumalai Kuladip Jana 《International journal of molecular sciences》2022,23(4)
Background: Breast cancer is the most common cancer in women globally, and diagnosing it early and finding potential drug candidates against multi-drug resistant metastatic breast cancers provide the possibilities of better treatment and extending life. Methods: The current study aimed to evaluate the synergistic anti-metastatic activity of Curcumin (Cur) and Paclitaxel (Pacli) individually, the combination of Curcumin–Paclitaxel (CP), and also in conjugation with gold nanoparticles (AuNP–Curcumin (Au-C), AuNP–Paclitaxel (Au-P), and AuNP–Curcumin–Paclitaxel (Au-CP)) in various in vitro and in vivo models. Results: The results from combination treatments of CP and Au-CP demonstrated excellent synergistic cytotoxic effects in triple-negative breast cancer cell lines (MDA MB 231 and 4T1) in in vitro and in vivo mouse models. Detailed mechanistic studies were performed that reveal that the anti-cancer effects were associated with the downregulation of the expression of VEGF, CYCLIN-D1, and STAT-3 genes and upregulation of the apoptotic Caspase-9 gene. The group of mice that received CP combination therapy (with and without gold nanoparticles) showed a significant reduction in the size of tumor when compared to the Pacli alone treatment and control groups. Conclusions: Together, the results suggest that the delivery of gold conjugated Au-CP formulations may help in modulating the outcomes of chemotherapy. The present study is well supported with observations from cell-based assays, molecular and histopathological analyses. 相似文献
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48.
Sree Hari Krishnan Parthasarathi R. Padmanabhan Hema A. Murthy 《International Journal of Speech Technology》2011,14(4):361-368
This paper demonstrates the robustness of group delay based features to additive noise. First, we analytically show the robustness
of group delay based representations. The analysis makes use of the fact that, for minimum-phase signals, the group delay
function can be represented in terms of the cepstral coefficients of the log-magnitude spectrum. Such a representation results
in the speech spectrum dominating over the noise spectrum, both at low and high SNRs. Further, we experimentally demonstrate
the robustness of the representation on a voice activity detection (VAD) task, comparing a group delay based VAD algorithm
with standard VAD methods as well as a magnitude-spectrum based method. 相似文献
49.
Alireza Bahadori Hari B. Vuthaluru 《International Journal of Pressure Vessels and Piping》2009,86(8):550-554
To determine whether any pressure variation in pipeline hydrostatic test is a result of temperature changes or the presence of leaks, the calculation of pressure/temperature changes is required for test sections. In these calculations, bulk modulus and volumetric expansion coefficient of fresh or sea water must be taken into account. In this study, a simple-to-use correlation is developed to predict the bulk modulus and volumetric expansion coefficient of both fresh and sea water as a function of temperature and pressure. The proposed correlation helps to cover the bulk modulus and volumetric expansion coefficient of both fresh and sea water for temperatures less than 50 °C (40 °C for sea water) as well as pressures up to 55,000 kPa (550 bar). The results can be used in follow-up calculations to determine whether any pressure variation in pipeline hydrostatic test is a result of temperature changes or the presence of leaks. The proposed correlation showed promising results with average absolute deviations for volumetric expansion coefficient and bulk modulus of water being around 0.58% and 0.08% respectively. The novel correlation is easy to use and will prove to be of immense value for project engineers to test the critical limits accurately. 相似文献
50.
Nepal, one of the least developed countries, is characterized by low per capita energy consumption and hugely dominated by traditional energy sources. Despite having enormous potential of hydro-electricity, only 50% of the total population has access to grid electricity. Firewood is the primary energy source for domestic purposes in rural environments. Due to geographical remoteness, a scattered consumer, higher costs of supply and maintenance, low consumption and low level of households’ income linking the rural areas to national electricity grid is difficult and implausible. In order to solve the energy problem in rural areas, Nepal’s government has initiated the production and distribution of several renewable energy technologies. Among several renewable technologies, micro-hydropower has been one of the most promising and widely adopted decentralized technologies to distribute electricity in rural areas. This article begins with a general overview of energy situation in Nepal. Present status and perspective of micro-hydro plants have also been discussed. Similarly, the dynamics of the relationship between electricity and socio-economic development has been analyzed by means of a typical rural electrification project in Tangting, Nepal by assessing the impacts of electricity on health, education, environment, and income in the village. The community has greatly benefitted from the arrival of environment friendly and affordable electricity. It has been concluded that the task of providing electricity to more remote and isolated villages is still challenging in Nepal. More systematic and comprehensive study supported by research and development is required to extend micro-hydro based electricity in more remote and poor communities of Nepal. 相似文献