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81.
Maggi L Catellani PL Fisicaro E Santi P Zani F Massimo G Colombo P 《AAPS PharmSciTech》2000,1(3):94-101
The aim of this work was to find a drying procedure for moist sucralfate gel capable of producing dried sucralfate gel that
retains the original gel properties of bioadhesion, rheology, and micromeritics. Spray-drying and microwave-drying procedures
were employed. Mannitol was used as a gel-protective substance during the drying processes. The spray drying of moist sucralfate
gel gave rise to a powder whose water suspensions showed significantly reduced viscosity. The bioadhesion of spray-dried sucralfate
gel was strongly reduced by drying. When mannitol was used as a gel protector, the spray-dried sucralfate in part maintained
the original bioadhesion of moist sucralfate gel. The preparation of a dried sucralfate gel retaining the bioadhesion characteristics,
avoiding the use of mannitol, was made possible using the microwavedrying procedure. The microwave-dried product possesses
a granular morphology suitable for direct compression because it is a free flowing and strongly coherent granular powder. 相似文献
82.
83.
Ricardo Barra Juan Carlos Colombo Gabriela Eguren Nadia Gamboa Wilson F. Jardim 《Neurochemical research》2000,25(1):1-1
Dedication
Special Issue Dedicated to Dr. Héctor S. Barra 相似文献84.
85.
Multiple AGAMOUS homologs from cucumber and petunia differ in their ability to induce reproductive organ fate. 总被引:9,自引:0,他引:9
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M M Kater L Colombo J Franken M Busscher S Masiero M M Van Lookeren Campagne G C Angenent 《The Plant cell》1998,10(2):171-182
The C function in Arabidopsis, which specifies stamen and carpel identity, is represented by a single gene called AGAMOUS (AG). From both petunia and cucumber, two MADS box genes have been isolated. Both share a high degree of amino acid sequence identity with the Arabidopsis AG protein. Their roles in specifying stamen and carpel identity have been studied by ectopic expression in petunia, resulting in plants with different floral phenotypes. Cucumber MADS box gene 1 (CUM1) induced severe homeotic transformations of sepals into carpelloid structures and petals into stamens, which is similar to ectopic AG expression in Arabidopsis plants. Overexpression of the other cucumber AG homolog, CUM10, resulted in plants with partial transformations of the petals into antheroid structures, indicating that CUM10 is also able to promote floral organ identity. From the two petunia AG homologs pMADS3 and Floral Binding Protein gene 6 (FBP6), only pMADS3 was able to induce homeotic transformations of sepals and petals. Ectopic expression of both pMADS3 and FBP6, as occurrs in the petunia homeotic mutant blind, phenocopies the pMADS3 single overexpresser plants, indicating that there is no additive effect of concerted expression. This study demonstrates that in petunia and cucumber, multiple AG homologs exist, although they differ in their ability to induce reproductive organ fate. 相似文献
86.
Involvement of distinct G-proteins, Gpa2 and Ras, in glucose- and intracellular acidification-induced cAMP signalling in the yeast Saccharomyces cerevisiae. 总被引:10,自引:0,他引:10
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S Colombo P Ma L Cauwenberg J Winderickx M Crauwels A Teunissen D Nauwelaers J H de Winde M F Gorwa D Colavizza J M Thevelein 《The EMBO journal》1998,17(12):3326-3341
Adenylate cyclase activity in Saccharomyces cerevisiae is dependent on Ras proteins. Both addition of glucose to glucose-deprived (derepressed) cells and intracellular acidification trigger an increase in the cAMP level in vivo. We show that intracellular acidification, but not glucose, causes an increase in the GTP/GDP ratio on the Ras proteins independent of Cdc25 and Sdc25. Deletion of the GTPase-activating proteins Ira1 and Ira2, or expression of the RAS2(val19) allele, causes an enhanced GTP/GDP basal ratio and abolishes the intracellular acidification-induced increase. In the ira1Delta ira2Delta strain, intracellular acidification still triggers a cAMP increase. Glucose also did not cause an increase in the GTP/GDP ratio in a strain with reduced feedback inhibition of cAMP synthesis. Further investigation indicated that feedback inhibition by cAPK on cAMP synthesis acts independently of changes in the GTP/GDP ratio on Ras. Stimulation by glucose was dependent on the Galpha-protein Gpa2, whose deletion confers the typical phenotype associated with a reduced cAMP level: higher heat resistance, a higher level of trehalose and glycogen and elevated expression of STRE-controlled genes. However, the typical fluctuation in these characteristics during diauxic growth on glucose was still present. Overexpression of Ras2(val19) inhibited both the acidification- and glucose-induced cAMP increase even in a protein kinase A-attenuated strain. Our results suggest that intracellular acidification stimulates cAMP synthesis in vivo at least through activation of the Ras proteins, while glucose acts through the Gpa2 protein. Interaction of Ras2(val19) with adenylate cyclase apparently prevents its activation by both agonists. 相似文献
87.
P. Risé S. Ghezzi C. Manzoni C. Colombo C. Galli 《Prostaglandins, leukotrienes, and essential fatty acids》2009,80(1):71-75
BackgroundStatins enhance the synthesis of long-chain polyunsaturated fatty acids (LC-PUFAs) from their precursors both in vitro and in vivo. In particular, an increased conversion of linoleic acid (LA) and of alpha-linolenic acid to their derivatives is observed in cultured cells. On the contrary, cigarette smoke (CS) negatively and dose-dependently affects the LC-PUFA production.AimTo evaluate the effects of CS alone or with simvastatin, on [1-14C] LA metabolism in THP-1 cells.ResultsCS inhibits LA conversion; after co-incubation, simvastatin nullifies the effects of CS, maintaining LA conversion comparable to controls. However, at the highest CS concentration, simvastatin is unable to counteract the effects of CS. Changes of LA conversion reflect the modulation of desaturase activities by simvastatin and CS.ConclusionCS decreases PUFA conversion and its effects are modulated by the opposite effect of statins. It can be speculated that statin treatments in smoking patients may provide some beneficial effects on PUFA metabolism in addition to lowering cholesterol levels. 相似文献
88.
Luiza Helena Urso Pitassi Pedro Paulo Vissotto de Paiva Diniz Diana Gerardi Scorpio Marina Rovani Drummond Bruno Grosselli Lania Maria Lourdes Barjas-Castro Rovilson Gilioli Silvia Colombo Stanley Sowy Edward B. Breitschwerdt William L. Nicholson Paulo Eduardo Neves Ferreira Velho 《PLoS neglected tropical diseases》2015,9(1)
Bartonella species are blood-borne, re-emerging organisms, capable of causing prolonged infection with diverse disease manifestations, from asymptomatic bacteremia to chronic debilitating disease and death. This pathogen can survive for over a month in stored blood. However, its prevalence among blood donors is unknown, and screening of blood supplies for this pathogen is not routinely performed. We investigated Bartonella spp. prevalence in 500 blood donors from Campinas, Brazil, based on a cross-sectional design. Blood samples were inoculated into an enrichment liquid growth medium and sub-inoculated onto blood agar. Liquid culture samples and Gram-negative isolates were tested using a genus specific ITS PCR with amplicons sequenced for species identification. Bartonella henselae and Bartonella quintana antibodies were assayed by indirect immunofluorescence. B. henselae was isolated from six donors (1.2%). Sixteen donors (3.2%) were Bartonella-PCR positive after culture in liquid or on solid media, with 15 donors infected with B. henselae and one donor infected with Bartonella clarridgeiae. Antibodies against B. henselae or B. quintana were found in 16% and 32% of 500 blood donors, respectively. Serology was not associated with infection, with only three of 16 Bartonella-infected subjects seropositive for B. henselae or B. quintana. Bartonella DNA was present in the bloodstream of approximately one out of 30 donors from a major blood bank in South America. Negative serology does not rule out Bartonella spp. infection in healthy subjects. Using a combination of liquid and solid cultures, PCR, and DNA sequencing, this study documents for the first time that Bartonella spp. bacteremia occurs in asymptomatic blood donors. Our findings support further evaluation of Bartonella spp. transmission which can occur through blood transfusions. 相似文献
89.
Airoldi C Zona C Sironi E Colombo L Messa M Aurilia D Gregori M Masserini M Salmona M Nicotra F La Ferla B 《Journal of biotechnology》2010,156(4):317-324
Curcumin derivatives with high chemical stability, improved solubility and carrying a functionalized appendage for the linkage to other entities, have been synthesized in a straightforward manner. All compounds retained Curcumin ability to bind Aβ peptide oligomers without inducing their aggregation. Moreover all Curcumin derivatives were able to stain very efficiently Aβ deposits. 相似文献
90.
Bastian Dislich Alessio Colombo Ulrike Zeitschel Joachim W Ellwart Elisabeth Kremmer Steffen Roßner Stefan F Lichtenthaler 《The EMBO journal》2010,29(17):3020-3032
The amyloid precursor protein (APP) undergoes constitutive shedding by a protease activity called α‐secretase. This is considered an important mechanism preventing the generation of the Alzheimer's disease amyloid‐β peptide (Aβ). α‐Secretase appears to be a metalloprotease of the ADAM family, but its identity remains to be established. Using a novel α‐secretase‐cleavage site‐specific antibody, we found that RNAi‐mediated knockdown of ADAM10, but surprisingly not of ADAM9 or 17, completely suppressed APP α‐secretase cleavage in different cell lines and in primary murine neurons. Other proteases were not able to compensate for this loss of α‐cleavage. This finding was further confirmed by mass‐spectrometric detection of APP‐cleavage fragments. Surprisingly, in different cell lines, the reduction of α‐secretase cleavage was not paralleled by a corresponding increase in the Aβ‐generating β‐secretase cleavage, revealing that both proteases do not always compete for APP as a substrate. Instead, our data suggest a novel pathway for APP processing, in which ADAM10 can partially compete with γ‐secretase for the cleavage of a C‐terminal APP fragment generated by β‐secretase. We conclude that ADAM10 is the physiologically relevant, constitutive α‐secretase of APP. 相似文献