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21.
Crude steam distillate from Ocimum gratissimum sprayed onto infection courts on detached cocoa pods moments after inoculation with Phytophthora palmivora completely inhibited the pathogen and blackpod lesion development on 75% of the infection courts. Disease suppression obtained with the extract was comparable to that obtained with a 2% Kocide 101 suspension. In the field, the O. gratissimum extract also suppressed lesion development although to a significantly lower (P = 0.05) extent in comparison with Kocide 101. Blackpod lesion expansion rates of 3.80, 3.56, 2.71 and 0.78 cm/day, respectively, were associated with pods treated in the field with C. citratus extract, tap water, O. gratissimum extract and 2% Kocide 101. The extract from Cymbopogon citratus was also ineffective on detached pods. Sporangia of P. palmivora from sporu-lating blackpod lesions on both detached and non-detached pods lost their infectivity within 1 h of treatment with the O. gratissimum extract. This effect was superior to that obtained with Kocide 101. Fungitoxicity of the extract on pods, however, was lost within 3 h of application. Thus, despite its in vivo effectiveness as an eradicant, the O. gratissimum extract, in its present form, has limited utility as a protectant fungicide. 相似文献
22.
Mayrel Palestino-Domínguez Alejandro Escobedo-Calvario Soraya Salas-Silva Moises Vergara-Mendoza Veronica Souza-Arroyo Roberto Lazzarini Roxana Miranda-Labra Leticia Bucio-Ortiz María Concepción Gutiérrez-Ruiz Luis E. Gomez-Quiroz 《Journal of biochemical and molecular toxicology》2023,37(4):e23302
Alcohol-induced pancreas damage remains as one of the main risk factors for pancreatitis development. This disorder is poorly understood, particularly the effect of acetaldehyde, the primary alcohol metabolite, in the endocrine pancreas. Hepatocyte growth factor (HGF) is a protective protein in many tissues, displaying antioxidant, antiapoptotic, and proliferative responses. In the present work, we were focused on characterizing the response induced by HGF and its protective mechanism in the RINm5F pancreatic cell line treated with ethanol and acetaldehyde. RINm5F cells were treated with ethanol or acetaldehyde for 12 h in the presence or not of HGF (50 ng/ml). Cells under HGF treatment decreased the content of reactive oxygen species and lipid peroxidation induced by both toxics, improving cell viability. This effect was correlated to an improvement in insulin expression impaired by ethanol and acetaldehyde. Using a specific inhibitor of Erk1/2 abrogated the effects elicited by the growth factor. In conclusion, the work provides mechanistic evidence of the HGF-induced-protective response to the alcohol-induced damage in the main cellular component of the endocrine pancreas. 相似文献
23.
Binding of [125I]calmodulin was characterized in highly purified synaptic plasma membrane (SPM) prepared from rat brain. By Scatchard analysis, the Ca2+-dependent membrane binding of [125I]calmodulin was found to have a Bmax of 284 pmol/mg protein and an apparent affinity with a Kd of 131 nM. Kinetic analysis indicates that at 37°C, the dissociation of [125I]calmodulinmembrane complexes follows first-order reaction and consists of two components: a dissociation constant (k) of 3.7×10–1 min–1 and a half-time (t1/2) of 1.8 min for the fast component, and a k of 4.8×10–2 min–1 and a t1/2 of 14.5 min for the slow component. At 0°C, substantial dissociation still occurred, with a k of 4.5×10–2 min–1 and a t1/2 of 15.3 min for the fast component, and a k of 5.5×10–3 min–1 and a t1/2 of 125.5 min for the slow component. These data on binding affinity and dissociation kinetics are consistent with the notion that SPM can readily and rapidly associated and dissociate calmodulin. In Arrhenius analysis of temperature effects, [125I]calmodulin binding to SPM exhibits a biphasic function, with the transition temperature (Td) estimated to be 23.8°C, suggesting that binding is influenced by lipid phase transition of the membrane. The binding of [125I]calmodulin to the synaptic membrane was found to be increased by corticosterone (10–7–10–6 M), a steroid hormone, and decreased by ethanol (50–200 mM), a centrally acting drug. Our data on the characteristics of calmodulin binding to the SPM provide groundwork for future studies on physiological and pharmacological regulation of calmodulin translocation to and from the plasma membrane in synaptic terminals.Abbreviations used CaM
calmodulin
- SPM
synaptic plasma membrane
- ATPase
adenosine triphosphatase
- Tris
tris(hydroxymethyl)aminomethane
- EGTA
ethylene-bis(oxyethylenenitrilo)tetraacetic acid
- SDS
sodium dodecyl sulfate
- TFP
trifluoperazine
- Kd
dissociation constant
- Bmax
maximum binding
- k
first-order rate constant
- t1/2
half-time
- Td
transition temperature 相似文献
24.
Maria E. Alvarez Alberto L. Rosa Esteban D. Temporini Adrian Wolstenholrne Graciela Panzetta Luis Patrito Hugo J.F. Maccioni 《Gene》1993,130(2):253-258
The fungus Neurospora crassa harbors large amounts of cytoplasmic filaments which are homopolymers of a 59-kDa polypeptide (P59Nc). We have used molecular cloning, sequencing and enzyme activity measurement strategies to demonstrate that these filaments are made of pyruvate decarboxylase (PDC, EC 4.1.1.1), which is the key enzyme in the glycolytic-fermentative pathway of ethanol production in fungi, and in certain plants and bacteria. Immunofluorescence analyses of 8–10-nm filaments, as well as quantitative Northern blot studies of P59Nc mRNA and measurements of PDC activity, showed that the presence and abundance of PDC filaments depends on the metabolic growth conditions of the cells. These findings may be of relevance to the biology of ethanol production by fungi, and may shed light on the nature and variable presence of filament bundles described in fungal cells. 相似文献
25.
The online photoreaction of the rose bengal photosensitized luminol–copper (II) chemiluminescence (CL) system was used for the determination of β-nicotinamide adenine dinucleotide (NADH) and ethanol (EtOH) in pharmaceutical formulations combined with a flow injection technique. NADH can significantly enhance the CL emission of the reaction. For EtOH, alcohol dehydrogenase in soluble form was utilized in the presence of nicotinamide adenine dinucleotide resulting in NADH production. The limit of detection (3σ blank, 𝑛 = 3) of 4.0 × 10−8 and 2.17 × 10−5 M, and linear range 1.3 × 10−7 to 2.5 × 10−5 M (R2 = 0.9998, n = 6) and 0.11–2.17 × 10−3 M (R2 = 0.9996, n = 6) were obtained for NADH and EtOH respectively. The injection rate was 100 h−1 with a relative standard deviation (n = 3) of 1.5–4.8% in the range studied for both analytes. The procedure was satisfactorily applied to pharmaceutical formulations with recoveries in the range 91.6 ± 3.0% to 110 ± 2.0% for NADH and 88 ± 3.0% to 95.4 ± 4.0% for EtOH. The results obtained were very consistent and did not differ considerably from the reported approaches at a 95% confidence limit. The possible mechanism of the CL reaction is also explained briefly. 相似文献
26.
Phenolic compounds were present in greater amounts in non‐infected petioles of genotypes of Hevea brasiliensis that are resistant to Phytophthora leaf disease than in genotypes that are susceptible. Phenolic compounds extracted from petioles of either susceptible (PB86) or resistant (RRIC100) genotypes, before or after infection with Phytophthora meadii, had anti‐fungal properties. Artificially infected petioles of PB86 had phenolic acids, triterpenoids or flavonoids, whereas healthy petioles contained only triterpenoids or flavonoids. However, healthy or infected petioles of RRIC100 contained only trace amounts of the above compounds and of vanillin (3‐methoxy‐4‐hydroxybenzaldehyde). Vanillin and umbelliferone (7‐hydroxycoumarin) were shown to suppress zoospore germination of P. meadii on glass slides and to inhibit its growth in pea broth and V‐8 juice agar. Vanillin was slightly more active than umbelliferone. Resistance of RRIC100 to Phytophthora was suspected as being related to the polymerisation of phenolic compounds to form lignin, which may suppress further spread of the pathogen's mycelium into healthy tissues. Formation of lignin from phenolic aldehydes as a barrier to disease spread may be a critical factor in resistance. 相似文献
27.
An optimized soy-based medium was developed for ethanol production byEscherichia coli KO11. The medium consists of mineral salts, vitamins, crude enzymatic hydrolysate of soy and fermentable sugar. Ethanol produced after 24 h was used as an endpoint in bioassays to optimize hydrolysate preparation. Although longer fermentation times were required with soy medium than with LB medium, similar final ethanol concentrations were achieved (44–45 g ethanol L–1 from 100 g glucose L–1). The cost of materials for soy medium (excluding sugar) was estimated to be $0.003 L–1 broth, $0.006 L–1 ethanol. 相似文献
28.
外源DNA或染色质在非洲爪蟾卵提取物中可以诱导细胞核样结构的重建。重建核除不具有核仁样结构外,在其它形态结构上与真核细胞核十分相似。前人的工作表明在重建核中具有核仁前体结构。但可能是由于缺少活性核仁组织者的缘故,这些核仁前体不能相互融合形成新生核仁。那么活性核仁组织者在重建核中是否能发挥其功能呢?为了研究这一问题,我们提取纯化了四膜虫的大核与大核的周边核仁。进一步去除大核的核被膜,并将去除核被膜的大核与大核核仁分别加入非洲爪赡卵非细胞体系中。通过电镜超薄切片观察,我们发现无论是与大核染色质相连的周边核仁还是分离纯化的核仁结构在非洲爪赡卵非细胞体系中都不能保持其原有结构特征,而是发生了典型核重建变化,并且在诱导形成的重建核中也看不到核仁样结构。这些结果说明具有活性的核仁组织者在加入非洲爪蟾卵提取物后既不能继续保持其原有的RNA转录功能也不能诱导新的核仁的出现。 相似文献
29.
K. Sudha Rani M. V. Swamy D. Sunitha D. Haritha G. Seenayya 《World journal of microbiology & biotechnology》1996,12(1):57-60
Two Clostridium thermocellum strains were improved for ethanol tolerance, to 5% (v/v), by gradual adaptation and mutation. The best mutant gave an ethanol yield of 0.37 g/g substrate, with a growth yield 1.5 times more than its parent. Accumulation of acids and reducing sugars by the mutant strain with 5% (v/v) ethanol was lower than that of the parent strain with 1.5% (v/v) ethanol. 相似文献
30.
O. Sergent I. Morel P. Cogrel M. Chevanne N. Pasdeloup P. Brissot G. Lescoat P. Cillard J. Cillard 《Biological trace element research》1995,47(1-3):185-192
Ethanol-induced lipid peroxidation was studied in primary rat hepatocyte cultures supplemented with ethanol at the concentration
of 50 mM. Lipid peroxidation was assessed by two indices: (1) conjugated dienes by second-derivative UV spectroscopy in lipid extract
of hepatocytes (intracellular content), and (2) free malondialdehyde (MDA) by HPLC-UV detection and quantitation for the incubation
medium (extracellular content). In cultures supplemented with ethanol, free MDA increased significantly in culture media,
whereas no elevation of conjugated diene level was observed in the corresponding hepatocytes. The cellular pool of low-mol-wt
(LMW) iron was also evaluated in the hepatocytes using an electron spin resonance procedure. An early increase of intracellular
LMW iron (≤1 hr) was observed in ethanol-supplemented cultures; it was inhibited by 4-methylpyrazole, an inhibitor of alcohol
dehydrogenase, whereas α-tocopherol, which prevented lipid peroxidation, did not inhibit the increase of LMW iron. Therefore,
the LMW iron elevation was the result of ethanol metabolism and was not secondarily induced by lipid hydroperoxides. Thus,
ethanol caused lipid peroxidation in rat hepatocytes as shown by the increase of free MDA, although no conjugated diene elevation
was detected. During ethanol metabolism, an increase in cellular LMW iron was observed that could enhance conjugated diene
degradation. 相似文献