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71.
Hydrodistilled oil obtained from the stem bark of Myrica esculenta Buch. Ham. ex D. Don (yield 0.3%) was analysed by capillary GC and GC-MS. The volatile oil consisted mainly of n-hexadecanol (25.2%), eudesmol acetate (21.9%), palmitic acid (11.6%), cis-β-caryophyllene (8.7%), n-pentadecanol (7.7%) and n-octadecanol (7.6%). The oil was found to be a potential antimicrobial agent against Bacillus pumilus, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Aspergillus niger and Saccharomyces cerevisiae. The essential oil exhibited significant topical anti-inflammatory activity compared to standard drug in Swiss albino mice ear. 相似文献
72.
A finite collection C of k‐sets, where is called a k‐clique if every two k‐sets (called lines) in C have a nonempty intersection and a k‐clique is a called a maximal k‐clique if and C is maximal with respect to this property. That is, every two lines in C have a nonempty intersection and there does not exist A such that , and for all . An elementary example of a maximal k‐clique is furnished by the family of all the k‐subsets of a ‐set. This k‐clique will be called the binomial k‐clique. This paper is intended to give some combinatorial characterizations of the binomial k‐clique as a maximal k‐clique. The techniques developed are then used to provide a large number of examples of mutually nonisomorphic maximal k‐cliques for a fixed value of k. 相似文献
73.
In this paper we present a graph-theoretic polynomial algorithm which has positive probability of finding a Hamiltonian path in a given graph, if there is one; if the algorithm fails, it can be rerun with a randomly chosen starting solution, and there is again a positive probability it will find an answer. If there is no Hamiltonian path, the algorithm will always terminate with failure. We call this a Successful Algorithm because it has high (close to 1) empirical probability of success and it works in polynomial time. Some basic theoretical results concerning spanning arborescences of a graph are given. The concept of a ramification index is defined and it is shown that ramification index of a Hamiltonian path is zero. The algorithm starts with finding any spanning arborescence and by suitable pivots it endeavors to reduce the ramification index to zero. Probabilistic properties of the algorithm are discussed. Computational experience with graphs up to 30 000 nodes is included. 相似文献
74.
Sanjay?Awasthi Kerri?L?Hallene Vince?Fazio Sharad?S?Singhal Luca?Cucullo Yogesh?C?Awasthi Gabriele?Dini Damir?JanigroEmail author 《BMC neuroscience》2005,6(1):61
Background
Permeability of the blood-brain barrier is one of the factors determining the bioavailability of therapeutic drugs and resistance to chemically different antiepileptic drugs is a consequence of decreased intracerebral accumulation. The ABC transporters, particularly P-glycoprotein, are known to play a role in antiepileptic drug extrusion, but are not by themselves sufficient to fully explain the phenomenon of drug-resistant epilepsy. Proteomic analyses of membrane protein differentially expressed in epileptic foci brain tissue revealed the frequently increased expression of RLIP76/RALBP1, a recently described non-ABC multi-specific transporter. Because of a significant overlap in substrates between P-glycoprotein and RLIP76, present studies were carried out to determine the potential role of RLIP76 in AED transport in the brain. 相似文献75.
Ghanshyam R. Jadhav Vijay J. Medhane Dattatray G. Deshmukh Sharad S. Gaikwad 《Journal of heterocyclic chemistry》2021,58(9):1775-1783
Chromenopyridines are an important class of compound because of their diverse biological activities. In the present work, we have developed convenient route for the synthesis of chromeno[4,3-b] pyridine derivatives ( 3a – e , 5a – e , and 7a – d ) by Friedlander condensation of 4-amino-2-oxo-2H-chromene-3-carbaldehyde with various active methylene compounds. We have used mixed metal oxide catalyst such as nanomaterial Zinc titanate. The reaction was carried out for various solvent systems, also we have altered the concentration of the catalyst. The 2-propanol/water solvent system and 5 mol% catalyst concentration are best as far as yield and rate of reaction are concerned. The structures of the synthesized compounds were confirmed by 1H NMR, 13C NMR, mass spectra, and elemental analysis. 相似文献
76.
Dr. Sharad S. Amin Dr. Kieran D. Jones Dr. Alexander J. Kibler Dr. Heather A. Damian Dr. Jamie M. Cameron Dr. Kevin S. Butler Dr. Stephen P. Argent Max Winslow Dr. David Robinson Dr. Nicholas J. Mitchell Prof. Hon Wai Lam Dr. Graham N. Newton 《Angewandte Chemie (International ed. in English)》2023,62(23):e202302446
Herein, we report the synthesis and characterization of a new class of hybrid Wells–Dawson polyoxometalate (POM) containing a diphosphoryl group (P2O6X) of the general formula [P2W17O57(P2O6X)]6− (X=O, NH, or CR1R2). Modifying the bridging unit X was found to impact the redox potentials of the POM. The ease with which a range of α-functionalized diphosphonic acids (X=CR1R2) can be prepared provides possibilities to access diverse functionalized hybrid POMs. Compared to existing phosphonate hybrid Wells–Dawson POMs, diphosphoryl-substituted POMs offer a wider tunable redox window and enhanced hydrolytic stability. This study provides a basis for the rational design and synthesis of next-generation hybrid Wells–Dawson POMs. 相似文献
77.
Elizabeth Hampson Jamie M. Cameron Sharad Amin Joungman Kyo Julie A. Watts Hiroki Oshio Graham N. Newton 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(50):18449-18453
Access to asymmetrically functionalized polyoxometalates is a grand challenge as it could lead to new molecular nanomaterials with multiple or modular functionality. Now, a simple one‐pot synthetic approach to the isolation of an asymmetrically functionalized organic–inorganic hybrid Wells–Dawson polyoxometalate in good yield is presented. The cluster bears two organophosphonate moieties with contrasting physical properties: a chelating metal‐binding group, and a long aliphatic chain that facilitates solvent‐dependent self‐assembly into soft nanostructures. The orthogonal properties of the modular system are effectively demonstrated by controlled assembly of POM‐based redox‐active nanoparticles. This simple, high‐yielding synthetic method is a promising new approach to the preparation of multi‐functional hybrid metal oxide clusters, supermolecular systems, and soft‐nanomaterials. 相似文献
78.
Due to continuous cutting tool usage, tool supervision is essential for improving the metal cutting industry. In the metal removal process tool, supervision is carried out either by an operator or online tool supervision. Tool supervision helps to understand tool condition, dimensional accuracy, and surface superiority. For downtime in the metal cutting industry, the main reasons are tool breakage and excessive wear, so it is necessary to supervise tool which gives better tool life and enhance productivity. This paper presents different conventional and artificial intelligence techniques for tool supervision in the processing procedures that have been depicted in writing. 相似文献
79.
Gurmeet Kaur Manpreet Kaur Lakhvir Sharad Manisha Bansal 《Journal of heterocyclic chemistry》2020,57(1):225-237
Antibiotics such as norfloxacin and ciprofloxacin are used to treat numerous bacterial infections. The present research work involves the molecular prediction, synthesis, characterization and in vitro antimicrobial activities of molecular hybrids of norfloxacin and ciprofloxacin. First set of compounds involve the substitutions of various amines at third position of ciprofloxacin and norfloxacin. On the other hand, second set of molecular hybrids include the substitution of different amines at seventh position along with linker (─COCH2─). These synthesized compounds were identified by TLC technique and well characterized by various spectroscopic techniques such as IR, NMR, and ESI-MS. Molecular prediction of these newly synthesized compounds have been carried out using the SwissADME, ADMETLab software. Their cytotoxicity parameters have also been studied using Osiris software. It was observed that almost all these molecular hybrids suitable for their drug likeness properties. Further, these newly synthesized compounds were subjected to study their antimicrobial activities in vitro. The third substituted as well as most of seventh substituted molecular hybrids have shown 10-folds increase in their antibacterial activity as compared to the standard drug ciprofloxacin. Some of these compounds have also shown their potency when subjected to study their cytotoxicity test against Escherichia coli AB 1157, proficient to prepare damage in DNA. 相似文献
80.
Rao AV Bhagat SD Hirashima H Pajonk GM 《Journal of colloid and interface science》2006,300(1):279-285
The experimental results on the synthesis of flexible and superhydrophobic silica aerogels using methyltrimethoxysilane (MTMS) precursor by a two-step (acid-base) sol-gel process followed by the supercritical drying, are reported. The effects of various sol-gel parameters on the flexibility of the aerogels have been investigated. The aerogels of different densities were obtained by varying the molar ratio of MeOH/MTMS (S) from 14 to 35, with lower densities for larger S values. It has been observed that the Young's modulus (Y) decreased from 14.11 x 10(4) to 3.43 x 10(4) N/m(2) with the decrease in the density of the aerogels from 100 to 40 kg/m(3). Simultaneously, the aerogels are superhydrophobic with a contact angle as high as 164 degrees . The superhydrophobic aerogels are thermally stable up to a temperature of 530 K, above which they become hydrophilic. The aerogels have been characterized by bulk density, percentage volume shrinkage, and porosity measurements. The microstructures of the aerogels have been studied using the transmission electron microscopy (TEM). The Young's modulus of the aerogels has been determined by an uniaxial compression test. The variation of physical properties of the aerogels has been explained by taking into consideration the hydrolysis, condensation reactions, the resulting colloidal clusters and their network formation. 相似文献