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111.
Bansal S Gaspari M Raj HG Kumar A Cuda G Verheij E Tyagi YK Ponnan P Rastogi RC Parmar VS 《Applied biochemistry and biotechnology》2008,144(1):37-45
Our earlier investigations identified acetoxy drug: protein transacetylase (TAase), a unique enzyme in the endoplasmic reticulum
(ER) catalyzing the transfer of acetyl groups from polyphenolic acetates (PA) to certain functional proteins. Recently we
have established the identity of TAase with ER protein calreticulin (CR) and subsequently transacetylase function of CR was
termed calreticulin transacetylase (CRTAase). CRTAase was purified and characterized from human placenta. CRTAase catalyzed
the acetylation of a receptor protein nNOS, by a model PA 7, 8-diacetoxy-4-methylcoumarin (DAMC), which was visually confirmed
by using antiacetyl lysine. The aim of this report was to provide tacit proof by providing mass spectrometry evidence for
CRTAase catalyzed acetylation of purified nNOS by DAMC. For this purpose, purified nNOS was incubated with DAMC and CRTAase,
the modified nNOS was analyzed by nanoscale LC-MS/MS, which recorded 11 distinct peptides with a significant score as acetylated
on lysine residues. The distribution was in order: lysines-24, -33, -38, -131, and -229 of the PDZ domain, Lys-245 of the
oxygenase domain, Lys-754 and -856 of FMN binding domain, Lys-989 of connecting domain and Lys-1300, -1321, and -1371 of the
NADPH-binding domain were acetylated. The results documented in this paper highlighted for the first time modification of
nNOS by way of acetylation. Our earlier work recorded the profound activation of platelet NADPH cytochrome P-450 reductase
and the acetylation of the reductase protein by DAMC, which also remarkably enhanced intracellular levels of nitric oxide.
The results reported here coupled with the aforementioned previous observations strongly implicate the possible role of the
acetylation of the reductase domain of nitric oxide synthase (NOS) in the NOS activation. In addition, the acetylation of
nNOS can be expected to potentiate the interaction with CR, eventually leading to the augmented catalytic activity of NOS
and expression of the related biological effects. 相似文献
112.
A relationship between the pressure and temperature of superheated liquid n-hexane and the critical electrostatic field required for inducing nucleation in it is obtained experimentally. This relation is used for the determination of the limit of stability of the liquid. 相似文献
113.
Krupa M. Parmar Zubeen J. Hathi Nishant A. Dafale 《Applied biochemistry and biotechnology》2017,181(3):1007-1029
The spread of multidrug-resistant (MDR) bacteria is an emerging threat to the environment and public wellness. Inappropriate use and indiscriminate release of antibiotics in the environment through un-metabolized form create a scenario for the emergence of virulent pathogens and MDR bugs in the surroundings. Mechanisms underlying the spread of resistance include horizontal and vertical gene transfers causing the transmittance of MDR genes packed in different host, which pass across different food webs. Several controlling agents have been used for combating pathogens; however, the use of lytic bacteriophages proves to be one of the most eco-friendly due to their specificity, killing only target bacteria without damaging the indigenous beneficial flora of the habitat. Phages are part of the natural microflora present in different environmental niches and are remarkably stable in the environment. Diverse range of phage products, such as phage enzymes, phage peptides having antimicrobial properties, and phage cocktails also have been used to eradicate pathogens along with whole phages. Recently, the ability of phages to control pathogens has extended from the different areas of medicine, agriculture, aquaculture, food industry, and into the environment. To avoid the arrival of pre-antibiotic epoch, phage intervention proves to be a potential option to eradicate harmful pathogens generated by the MDR gene flow which are uneasy to cure by conventional treatments. 相似文献
114.
115.
Abstract Polymer dispersed liquid crystal thin films have been deposited on glass substrates by the processes of polymerization and solvent evaporation induced phase separation. The electron and the optical polarization microscopies of the films reveal that PDLC microdroplets formed during the process of phase separation near the top surface of the film remain exposed and respond to shear stress due to air or gas flow on the surface. Optical response of the film to an air flow-induced shear stress input on the free surface has been measured. Director orientation in the droplets changes with the applied shear stress leading to time varying transmitted light intensity. Director dynamics of the droplet for an applied step shear stress has been discussed from free energy considerations. Results on the measurement of light transmission as a function of the gas flow parameter unambiguously demonstrate the potential of these systems for use as boundary layer and gas flow sensors. 相似文献
116.
In a wide search program for new and efficient antimicrobial agents, a series of oxadiazole/azetidinone-incorporated benzimidazoles have been synthesized and evaluated against different Gram-positive and Gram-negative bacteria. Derivatives having long alkyl chain on the oxadiazole/azetidinone moiety with three or more carbon atoms have shown less antibacterial activity. 相似文献
117.
118.
A simple, selective, rapid, and economical reversed phase high performance liquid chromatography(RP-HPLC) method for the determination of doxofylline in the commercial dosage form has been developed and validated. The separation
and quantification were achieved on an HiQ Sil C 18 W column using a mobile phase of acetonitrile: buffer (50: 50), pH 3,
at a flow rate of 1 mL/min with detection of analyte at 272 nm. The separation was achieved within 3.1 ± 0.3 min for doxofylline
sample. The method showed good linearity in the range of 10–80 μg/mL. The intra and inter day RSD ranged from 0.37–0.53%.
The recovery (mean ± S.D.) of low, middle and high concentrations were 100.04 ± 0.80, 100.01 ± 0.20, 100.07 ± 0.30 respectively.
Limit of detection and limit of quantification were 0.03 and 0.1 μg/mL, respectively. 相似文献
119.
Ravi Mosurkal Lynne A. Samuelson Kenneth D. Smith Phillip R. Westmoreland Virinder S. Parmar Fadong Yan 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(11):942-946
Composites of titanium dioxide (TiO2) nanoparticles and biocatalytically synthesized dimethylsiloxane copolyamides were prepared, and their thermal and flame-retardant properties were investigated. The flammability properties such as heat release capacity and total heat release were measured from microscale cumbustion calorimetry (MCC). The thermal degradation temperatures, char yields, and the heat-release capacities of these nanocomposites were significantly improved over the pure polymers. The heat-release capacities of the siloxane copolymer nanocomposites with 20wt% of TiO2 were found to be 167 and 129 J/g K, which is a 35% less than the pure polymers (260 and 194 J/g K, respectively). The SEM/EDAX surface-analysis studies on nanocomposite films and their char revealed that nanocrystalline-TiO2 plays an important role in forming carbonaceous silicate char on the surface as a protective layer. 相似文献
120.
A series of metal complexes of Zn(II) and Hg(II) having the general composition [ML2]X2 with thiosemicarbazide have been prepared and characterized by elemental chemical analysis, molar conductance, and spectral
(IR and mass) studies. The IR spectral data suggest the involvement of sulfur and terminal amino nitrogen in coordination
to central metal ion. On the basis of spectral studies, a tetrahedral geometry has been assigned for the Zn(II) and Hg(II)
complexes. Thiosemicarbazide and its metal complexes have been tested in vitro against a number of microorganisms in order
to assess their antimicrobial properties.
The article is published in the original. 相似文献