排序方式: 共有186条查询结果,搜索用时 15 毫秒
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152.
Karthik Nuthalapati Raviraj Vankayala Chi-Shiun Chiang Kuo Chu Hwang 《Particle & Particle Systems Characterization》2020,37(5):2000001
Development of simple, robust, and noninvasive therapeutic approaches to treat cancers and improve survival rates is a grand challenge in clinical biomedicine. In particular, the sizes and shape of the nanomaterials play a vital role in dictating their biodistribution and clearance pathways. It remains elusive how the size and shape of a nanomaterial affect its therapeutic efficacy in cancer diagnosis and treatments. To tackle the above problem, the effects of size and shape of Cu2(OH)PO4 nanostructures (nanosheets and quantum dots) on the photodynamic therapy (PDT) in destroying malignant drug-resistant lung tumors and on combating the tumor hypoxia problem are investigated and compared. The photocatalytic mechanism of Cu2(OH)PO4 nanostructures mainly involves the generation of reactive oxygen species (ROS), such as hydroxyl radical (·OH) and singlet oxygen (1O2). Under an oxygen deprivation condition, Cu2(OH)PO4 nanosheets still can generate OH radicals to kill cancer cells upon near-infrared (NIR) light irradiation. Overall, in vitro and in vivo experiments show that Cu2(OH)PO4 nanosheets can overcome tumor hypoxia problems and effectively mediate dual modal PDT and photothermal therapeutic (PTT) effects on destruction of NCI-H23 lung tumors in mice using ultralow doses (350 mW cm−2) of NIR (915 nm) light. 相似文献
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154.
Synthesis of Dithiocarbamates Containing Disulfide Linkage Using Cyclic Trithiocarbonate and Amines under Solvent–Catalyst Free Condition 下载免费PDF全文
Nand Lal Amit Sarswat Lalit Kumar Karthik Nandikonda Santosh Jangir Veenu Bala Vishnu Lal Sharma 《Journal of heterocyclic chemistry》2015,52(1):156-162
A green and facile synthesis of dithiocarbamate derivatives containing disulfide linkage by the ring opening reaction of trithiocarbonate with amines under solvent and catalyst‐free condition with excellent yields is being reported. Environmental benignity, easy work up, smaller reaction time, and lack of column chromatography are the significant features of this protocol. The cyclic trithiocarbonate ( 1 ) has been used as a starting material for the first time to synthesize compounds of biological interest ( 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h , 3i , 3j , 3k , 3l , 3m , 3n , 3o , 3p , 3q ). 相似文献
155.
A highly regio- and stereoselective method has been developed for the synthesis of spiro[furo[3,4-c]chromene-1,3′-indoline]-2′,4(9bH)-dione derivatives via a three component reaction of cyclic diazoamide and aldehyde with methyl 2-oxo-2H-chromene-3-carboxylate, 3-acetyl-2H-chromen-2-one and 3-benzoyl-2H-chromen-2-one using 3 mol % of Rh2(OAc)4. Similarly, acyclic diazoesters also undergo smooth coupling with carbonyl compounds and 3-substituted coumarin in the presence of 1 mol % of Rh2(OAc)4 to afford a novel series of tetrahydro-1H-furo[3,4-c]chromene-1-carboxylates in 78–88% yield with high regio- and stereo-selectivity for the first time. 相似文献
156.
Potentiostatic Electrochemical Preparation of Bismuth Nanoribbons and its Application in Biologically Poisoning Lead and Cadmium Heavy Metal Ions Detection 下载免费PDF全文
Rajkumar Devasenathipathy Raj Karthik Shen‐Ming Chen Veerappan Mani V. S. Vasantha M. Ajmal Ali Mohamed S. Elshikh Bih‐Show Lou Fahad M. A. Al‐Hemaid 《Electroanalysis》2015,27(10):2341-2346
A simple and elegant electrochemical potentiostatic method has been described for the preparation of highly stable and electrocatalytically active bismuth nanoribbons (BiNRs). The average length and width of the BiNRs were of 100±50 nm and 10±5 µm, respectively. Here, disodium ethylene diamine tetraacetate was employed as a scaffold for the growth of BiNRs. The formation of BiNRs was confirmed by surface morphological, elemental and cyclic voltammetric analyses. The BiNRs exhibited excellent electrocatalytic ability in detecting biologically poisoning heavy metal ions such as lead and cadmium. The described BiNRs based sensor presents good linear dependence on lead and cadmium ions in the concentration range of 1–50 µg/L for both metal ions with a detection limit of 0.104 µg/L for lead and 0.145 µg/L for cadmium. 相似文献
157.
Relationship between electrophilicity index, Hammett constant and nucleus-independent chemical shift
M. Elango R. Parthasarathi G. Karthik Narayanan A. Md. Sabeelullah U. Sarkar N. S. Venkatasubramaniyan V. Subramanian P. K. Chattaraj 《Journal of Chemical Sciences》2005,117(1):61-65
Inter-relationships between the electrophilicity index (Ω), Hammett constant (óp
@#@) and nucleusindependent chemical shift (NICS (1) — NICS value one ?ngstrom above the ring centre) have been investigated for
a series of meta- and para-substituted benzoic acids. Good linear relationships between Hammett constant vs electrophilicity
and Hammett constant vs NICS (1) values have been observed. However, the variation of NICS (1) against CO shows only a low
correlation coefficient. 相似文献
158.
Adéla Zemanová Olga Semenova Ale? Kroupa Jan V?e?t’ál Karthik Chandrasekaran Klaus W. Richter Herbert Ipser 《Monatshefte für Chemie / Chemical Monthly》2005,29(5):1931-1937
Phase equilibria in the Ag–In–Pd system were determined at 700°C based on experimental results for 21 alloys. A ternary compound
T1 (with the approximate composition AgInPd2) was identified by XRD analysis. These data were compared with the results of a CALPHAD-type prediction, based on binary
thermodynamic data only and a symmetrical Redlich–Kister–Muggianu model. The experimental results will serve as a basis for refined thermodynamic modeling of the different phases in this
ternary system. 相似文献
159.
N. Sankara Subramanian B. Santhi T. Sornakumar G. Karthik Subbaraj C. Vinoth G. Murugan 《Ionics》2004,10(3-4):273-282
Undoped and antimony doped tin oxide thin films of different thicknesses were prepared on mineral glass substrate by spray
pyrolysis method via sol-gel route. Both the films show good transmittance in the visible region. Band gap energy of both
films lies between 3 to 3.5 eV. X-ray diffraction studies of undoped and antimony doped tin oxide thin films for various annealing
temperature show polycrystalline tetragonal structure of SnO2 with preferred orientation of (110) and (101), respectively and from the XRD data, grain size were also evaluated. AFM images
of Undoped and antimony doped tin oxide thin films annealed at 375 °C depict the film thickness and indicate uniform surface
pattern without dark pits and with strains of some ups exceeding the specified limit. The prepared films were tested in a
specially developed test rig for Liquefied Petroleum Gas detection at different operating temperatures. The response characteristics
of the films for LPG detection show maximum sensitivity and minimum response time at the operating temperature 400 °C. Studies
indicate that antimony doped tin oxide thin film are one among the suitable candidates for LPG detection with a detection
sensitivity and response time (t90) of 11 and 140 seconds, respectively.
Paper presented at the 2nd International Conference on Ionic Devices, Anna University, Chennai, India, Nov. 28–30, 2003. 相似文献
160.
Vishwas Akavaram Kush Kumar Shreya Sriram Saisrinath Narra Akshant Kumawat Santosh Kumar Meena Karthik Pushpavanam 《Macromolecular bioscience》2023,23(11):2300091
Counterfeited biomedical products result in significant economic losses and pose a public health hazard for over a million people yearly. Hydrogels, a class of biomedical products, are being investigated as alternatives to conventional biomedical products and are equally susceptible to counterfeiting. Here, a biocompatible, physically unclonable function (BPUF) to verify the authenticity of therapeutically relevant hydrogels are developed. The principle of BPUF relies on the self-assembly of tyrosine into fibril-like structures which are incorporated into therapeutically relevant hydrogels resulting in their random dispersion. This unclonable arrangement leads to distinctive optical micrographs captured using an optical microscope. These optical micrographs are transformed into a unique security code through cryptographic techniques which are then used to authenticate the hydrogel. The temporal stability of the BPUFs are demonstrated and additionally, exploit the dissolution propensity of the structures upon exposure to an adulterant to identify the tampering of the hydrogel. Finally, a platform to demonstrate the translational potential of this technology in validating and detecting tampering of therapeutically relevant hydrogels is developed. The potential of BPUFs to combat hydrogel counterfeiting is exemplified by its simplicity in production, ease of use, biocompatibility, and cost-effectiveness. 相似文献