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排序方式: 共有1931条查询结果,搜索用时 171 毫秒
901.
Ildikó Seres Gabriella Fóris Zsuzsa Varga Béla Kosztáczky Andrea Kassai Zoltán Balogh Péter Fülöp György Paragh 《The Journal of membrane biology》2006,214(1-2):91-98
Angiotensin II (Ang II) is able to induce free radical generation in neutrophils, which is more elevated in neutrophils of
patients with hypercholesterolemia (HC). In addition, the signal processing through angiotensin I (Ang I) receptors is altered.
In present study, we compared the Ang II-triggered free radical generation of neutrophils obtained from patients with relatively
isolated forms of metabolic syndrome (MS) with membrane-bound cholesterol content and membrane fluidity. We determined the
enhancement of Ang II-induced superoxide anion and leukotriene C4 (LTC4) generation, membrane fluidity and cell-bound cholesterol content of neutrophils obtained from 12 control subjects, 11 patients
with obesity (Ob), 10 patients with type 2 diabetes mellitus (t2-DM) and 12 patients with HC. The alteration of signal processing
was studied after preincubation with different inhibiting drugs. Superoxide anion, LTC4 production and membrane rigidity were increased in the following order: control < Ob < t2-DM < HC. Both Ang II-induced superoxide
anion and LTC4 generation were decreased in control cells by pertussis toxin and fluvastatin (Flu), whereas in each patient group, mepacrin,
verapamil and Flu were effective, suggesting alterations in signal pathways, which may be attributed to isoprenylation. The
enhancement of superoxide anion and LTC4 generation correlated significantly with membrane rigidity, independently from the experimental groups and membrane-bound
cholesterol content. Membrane rigidity of neutrophils, obtained from patients with MS, plays a role in Ang II-induced free
radical generation independent of intracellular cholesterol homeostasis. 相似文献
902.
Stefanovits-Bányai E Szentmihályi K Hegedus A Koczka N Váli L Taba G Blázovics A 《Life sciences》2006,78(10):1049-1056
A comparative study was carried out to determine some valuable phytochemical components, macro- and microelement and redox parameters in leaves of male and female Ginkgo biloba trees and in extracts made from them. G. biloba extracts have become more popular as a therapeutic agent in the modern pharmacology in neurodegenerative diseases, in which increased brain metal levels can be observed and free radical reactions are involved. Macro- and microelement components, total phenol content, H-donating activity and reducing power as well as total scavenger capacity were determined in the samples. Well detectable differences were obtained for micro- and macroelement contents between male and female samples, but no toxic elements could be detected in the extracts. Male extracts contained more hazardous metals (e.g. Fe) compared to the female ones, while extracts from female leaves had higher levels of ions, which are known to have beneficial effects in neurodegenerative diseases. The ethanolic extracts of male leaves showed the highest H-donating activity, reducing power and total phenol content, as well as the best total scavenger activity. Ginkgo extracts due to the antioxidant properties may have favourable effects as dietary supplements in several neurodegenerative diseases, but this study draws the attention that critical evaluation is required in view of the potential hazard induced by their metal ion constitution. Our results lead us to the conclusion that although the aqueous extracts of female leaves are characterized by relatively lower antioxidant properties, they may be more eligible for these purposes due to their favourable metal ion constitution. 相似文献
903.
Santini MT Romano R Rainaldi G Indovina P Ferrante A Motta A Indovina PL 《Radiation research》2006,166(5):734-745
The metabolic changes that occur as a function of time in MG-63 osteosarcoma three-dimensional tumor spheroids undergoing radiation-induced apoptosis were studied using high-resolution proton nuclear magnetic resonance ((1)H-NMR) spectroscopy. Specifically, the (1)H-NMR spectra of MG-63 spheroids collected at 24, 48 and 72 h after exposure to 5 Gy of ionizing radiation were compared to the spectra of their respective controls. Small spheroids (about 50-80 microm in diameter) with no hypoxic center were used. Apoptosis was verified by both staining of spheroid DNA with the Hoechst 33258 dye and determination of caspase 3 enzyme activity at the three times examined. The results demonstrate that, as the percentage of apoptosis rises with time after exposure to ionizing radiation, the metabolic changes that take place in MG-63 spheroids follow very precise temporal dynamics. In particular, significant time-related increases in both CH(2) and CH(3) mobile lipids, considered by many authors as markers of apoptosis, were observed. In addition, temporal variations were also observed in choline-containing metabolites, reduced glutathione (GSH), glutamine/glutamate, taurine, alanine, creatine/phosphocreatine and lactate. These data show that in addition to CH(2) and CH(3) lipids, other metabolites can also be extremely useful in a deeper understanding of the temporal dynamics of radiation-induced apoptosis. This comprehension is particularly important in spheroids, a cell model of great complexity that resembles in vivo tumors much more closely than monolayer cultures. Ultimately, it is hoped that such studies can help to evaluate the outcome of radiotherapy protocols more accurately. 相似文献
904.
Michailova P Ilkova J Hankeln T Schmidt ER Selvaggi A Zampicinini G Sella G 《Genetica》2009,135(2):137-148
Structural aberrations, their frequency and distribution as well as distribution of the tandem repetitive minisatellite DNA
clusters of Alu and Hinf elements and two retroelements, the LINE NLRCth1 and the SINE CTRT1, were analyzed in the genome
of the chironomid C. piger Strenzke larvae from a Bulgarian population. A consistent somatic variability in the structure of the polytene chromosomes
was detected, showing that the C. piger genome is more actively rearranging than supposed before. Breakpoints were concentrated in proximal parts of chromosomes
significantly more often than in distal parts. By FISH analysis we could detect only one locus containing Alu elements and
38 Hinf cluster loci which appear to be dispersed equally all over the chromosomes. The retrotransposons NLRCth1 and CTRT1
are present only in a few loci, but highly variant among different individuals. The mean number of NLRCth1 sites per individual
was 18.4 ± 2.09 and of CTRT1 was 54.8 ± 8.42. A third of breakpoint locations were close to or coincide with a locus occupied
by a retroelement (either NLRCth1 or CTRT1). Nineteen percent of breakpoints coincided with Hinf repetitive DNA elements.
Some breakpoints were identical in the two sibling species C. piger and C. riparius Meigen (syn.: C. thummi thummi) and are considered as conserved hot spots of chromosome breakage. 相似文献
905.
The reaction of trans-[RuIII(AsPh3)2Cl3(CH3OH)] (green powder) with 2-thiopyrimidine-1,3, HTPYM, in ethanol, produced red crystals of trans,cis,cis-[RuII(AsPh3)2(N,S-2-thiopyrimidinato)2]. The compound has two TPYM− chelating anions in the equatorial plane, whereas the As atoms occupy the apical positions. It is stable in the solid state but the yellow chloroform solutions turn to green quickly in air atmosphere. The Ru-As, Ru-S and Ru-N bond distances average 2.432(1), 2.440(2) and 2.078(6) Å, respectively. The AsPh3 ligands assume a semi-trefoil C1 arrangement and have C-H?S intra-molecular hydrogen bond type interactions to TPYM− ligands. These latter ligands are also involved in C-H?N and C-H?S interactions that pair two thiobase ligands via an unusual way. Density functional computational studies on [Ru(AsH3)2(N,S-TPYM)2] model molecules show that the cis,cis,trans isomer is more stable than the trans,cis,cis one by some 5 kcal mol−1. 相似文献
906.
Palmieri G Langella E Gogliettino M Saviano M Pocsfalvi G Rossi M 《Molecular bioSystems》2010,6(12):2498-2507
This work describes the identification and characterization of a Sulfolobus solfataricus acylpeptide hydrolase, named APEH(Ss), recognised as a new protease target of the endogenous PEBP inhibitor, SsCEI. APEH is one of the four members of the prolyl oligopeptidase (POP) family, which removes acylated amino acid residues from the N terminus of oligopeptides. APEH(Ss) is a cytosolic homodimeric protein with a molecular mass of 125 kDa. It displays a similar exopeptidase and endopeptidase activity to the homologous enzymes from Aeropyrum pernix and Pyrococcus horikoshii. Herein we demonstrate that SsCEI is the first PEBP protein found to efficiently inhibit APEH from both S. solfataricus and mammalian sources with IC(50) values in the nanomolar range. The 3D model of APEH(Ss) shows the typical structural features of the POP family including an N-terminal β-propeller and a C-terminal α/β hydrolase domain. Moreover, to gain insights into the binding mode of SsCEI toward APEH(Ss), a structural model of the inhibition complex is proposed, suggesting a mechanism of steric blockage on substrate access to the active site or on product release. Like other POP enzymes, APEH may constitute a new therapeutic target for the treatment of a number of pathologies and this study may represent a starting point for further medical research. 相似文献
907.
Lucia Briatore Barbara Salani Gabriella Andraghetti Davide Maggi Gian Franco Adami Nicola Scopinaro Renzo Cordera 《Obesity (Silver Spring, Md.)》2010,18(5):932-936
In subjects with obesity and type 2 diabetes mellitus (T2DM), biliopancreatic diversion (BPD) improves glucose stimulated insulin secretion, whereas the effects on other secretion mechanisms are still unknown. Our objective was to evaluate the early effects of BPD on nonglucose‐stimulated insulin secretion. In 16 morbid obese subjects (9 with T2DM and 7 with normal fasting glucose (NFG)), we measured insulin secretion after glucose‐dependent arginine stimulation test and after intravenous glucose tolerance test (IVGTT) before and 1 month after BPD. After surgery the mean weight lost was 13% in both groups. The acute insulin response during IVGTT was improved in T2DM after BDP (from 55 ± 10 to 277 ± 91 pmol/l, P = 0.03). A reduction of insulin response to arginine was observed in NFG, whereas opposite was found in T2DM. In particular, acute insulin response to arginine at basal glucose concentrations (AIRbasal) was reduced but insulin response at 14 mmol/l of plasma glucose (AIR14) was increased. Therefore, after BPD any statistical difference in AIR14 between NFG and T2DM disappeared (1,032 ± 123 for NFG and 665 ± 236 pmol/l for T2DM, P = ns). The same was observed for SlopeAIR, a measure of glucose potentiation, reduced in T2DM before BPD but increased after surgery, when no statistically significant difference resulted compared with NFG (SlopeAIR after BPD: 78 ± 11 in NFG and 56 ± 18 pmol/l in T2DM, P = ns). In conclusion, in obese T2DM subjects 1 month after BPD we observed a great improvement of both glucose‐ and nonglucose‐stimulated insulin secretions. The mechanisms by which BDP improve insulin secretion are still unknown. 相似文献
908.
Gabriella Gaglio Simon Allen Lee Bowden Mark Bryant Eric R. Morgan 《European Journal of Wildlife Research》2010,56(6):839-844
Seventy-four European hedgehogs (Erinaceus europaeus) that had died in wildlife rehabilitation centres were dissected and their parasite burdens documented. Overall parasite
prevalence was 91%, and a total of six helminth species were isolated: five nematodes (Crenosoma striatum, Eucoleus aerophilus, Capillaria erinacei, Capillaria ovoreticulata and Capillaria spp.), one trematode (Brachylaemus erinacei) and one acanthocephalan (Oliganthorhynchus erinacei). The tick Ixodes hexagonus and flea Archeopsylla erinacei were also collected. The effect of parasite infection on body condition was assessed by correlation of burdens with the residuals
of weight–skeletal length regression. Tick presence was positively related to body condition; for other parasites, no significant
relationship was found. Faecal egg or larval count was closely correlated with adult parasite burden for C. striatum and Capillaria/Eucoleus spp., but not for other species. Coprological analysis should therefore be useful for in vivo studies of nematode parasite
infection in hedgehogs. The epidemiology of parasites in hedgehogs and their possible role in recent population declines are
discussed. 相似文献
909.
Retrotransposon-based molecular markers for grapevine species and cultivars identification 总被引:2,自引:0,他引:2
Claudio D’Onofrio Gabriella De Lorenzis Tommaso Giordani Lucia Natali Andrea Cavallini Giancarlo Scalabrelli 《Tree Genetics & Genomes》2010,6(3):451-466
Insertional polymorphisms of two copia-like (Vine-1, Tvv1) and one gypsy-like (Gret1) retrotransposon found in the grapevine genome were studied in 29 Vitis genotypes (Vitis arizonica, Vitis cinerea, Vitis labrusca, Vitis rupestis, Vitis rotundifolia, Vitis vinifera subsp. sylvestris and 23 V. vinifera subsp. sativa) using inter-retrotransposon amplified polymorphism (IRAP), retrotransposon-microsatellite amplified polymorphism (REMAP)
and sequence-specific amplified polymorphism (SSAP) techniques. IRAP, REMAP and SSAP polymorphisms were compared with amplified
fragment length polymorphism (AFLP), Inter-single sequence repeats (ISSR) and SSR polymorphisms by evaluating the information
content, the number of loci simultaneously analysed per experiment, the effectiveness of the analyses in assessing the relationship
between accessions and the number of loci needed to obtain a coefficient of variation of 10%. The UPGMA dendrograms of each
molecular marker system were compared and the Mantel matrix correspondence test was applied. Furthermore, the corresponding
insertion ages of the transposable elements were estimated for each retrotransposon subfamily analysed. The presence of Gret1, Tvv1 and Vine-1 retrotransposons in all analysed genotypes suggests that copia-like and gypsy-like retrotransposons are widespread in Vitis genus. The results indicate that these retrotransposons were active before Vitis speciation and contributed to Vitis genus evolution. IRAP, REMAP and SSAP markers allow the discrimination of Vitis species and V. vinifera subsp. sativa cultivars with certainty as has been shown with AFLP, ISSR and SSR analyses, but phylogenetic trees obtained by retrotransposon-based
molecular markers polymorphisms show some significant differences in the allocation of the analysed accessions compare to
those obtained by ISSR, AFLP and SSR molecular markers. The phylogenetic tree resulting from REMAP polymorphism appeared the
most representative of the effective relationship between all analysed accessions. 相似文献