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61.
Abstract An new water-soluble Pd(II) complex, 2,2'-bipyridin n-butyl dithiocarbamato Pd(II) nitrate has been synthesized. The Pd(II) complex has been characterized by elemental analysis and conductivity measurements as well as spectroscopic methods such as infrared, 1H NMR, and ultraviolet-visible. The interaction between this new design Pd(II)-complex, an anti-tumor component, with carrier proteins of β-lactoglobulin-A and -B (BLG-A and -B) were studied at different temperatures of 27, 37, 42, and 47 °C by fluorescence spectroscopy and far-UV circular dichroism (CD) spectrophotometric techniques. A strong fluorescence quenching interaction of Pd(II) complex with BLG-A and -B was observed at different temperatures. The binding parameters were evaluated by fluorescence quenching method. The thermodynamic parameters, including ΔH°, ΔS°, and ΔG° were calculated by fluorescence quenching method indicated that the electrostatic and hydrophobic forces might play a major role in the interactions of Pd(II) complex with BLG-A and -B, respectively. The distances between donors (Trps of the BLG-A and -B) and acceptor (Pd(II) complex) were obtained according to the fluorescence resonance energy transfer (FRET). Far-UV CD studies showed that the Pd(II) complex did not represent any significant changes in the secondary structures of BLG- A and -B. The difference in the interaction properties observed for BLG-A and -B with Pd(II) complex is related to the difference in the amino acid sequences between these two variants.  相似文献   
62.
Successful clinical experience of using cisplatin and its derivatives in cancer therapy has encouraged scientists to synthesize new metal complexes with the aim of interacting with special targets such as proteins In this regard, biological effects of [Pt(FIP)(Phen)](NO3)2 compound which contains a novel phen-imidazole ligand, FIP, was investigated on bovine liver catalase (BLC) structure and function. Various spectroscopic methods such as UV–visible, fluorescence, and circular dichroism (CD) were applied at two temperatures 25 and 37°C for kinetics and structural studies. As a consequence, the enzymatic activity decreased slightly with increasing the platinum compound’s concentration up to 30 μM and then remained constant at near 80% after this concentration. On the other hand, the fluorescence quenching measurements revealed that despite slight changes in activity, catalase experiences notable alterations in three-dimensional environment around the chromophores of the enzyme structure with increasing platinum complex concentration. Moreover, quenching data showed that BLC has two binding sites for Pt complex and hydrogen bonding interactions play a major role in the binding process. Furthermore, CD spectroscopy data showed that Pt(II) complex induces significant decrease in α-helix content of the secondary structure of BLC, but notable increase in random coil proportion accompanying a slight decrease in β-sheet content. All in all, hydrogen bonding interactions which are mainly involved in the binding process of the novel phen-imidazole compound to BLC significantly alter the protein structure but slightly change its function. This might be a promising outcome for chemotherapists and medicinal chemists to investigate in vivo properties of this novel metal complex with significant binding tendency to a macromolecule in the low concentrations without decreasing its intrinsic function.  相似文献   
63.
IntroductionN-palmitoylethanolamine (PEA) is an endogenous fatty acid amide belonging to the family of the N-acylethanolamines (NAEs). Recently, several studies demonstrated that PEA is an important analgesic, antiinflammatory, and neuroprotective mediator. The aim of this study was to investigate the effect of co-ultramicronized PEA + luteolin formulation on the modulation of the inflammatory response in mice subjected to collagen-induced arthritis (CIA).MethodsCIA was induced by an intradermally injection of 100 μl of the emulsion (containing 100 μg of bovine type II collagen (CII)) and complete Freund adjuvant (CFA) at the base of the tail. On day 21, a second injection of CII in CFA was administered. Mice subjected to CIA were administered PEA (10 mg/kg 10% ethanol, intraperitoneally (i.p.)) or co-ultramicronized PEA + luteolin (1 mg/kg, i.p.) every 24 hours, starting from day 25 to 35.ResultsMice developed erosive hind-paw arthritis when immunized with CII in CFA. Macroscopic clinical evidence of CIA first appeared as periarticular erythema and edema in the hindpaws. The incidence of CIA was 100% by day 28 in the CII-challenged mice, and the severity of CIA progressed over a 35-day period with a resorption of bone. The histopathology of CIA included erosion of the cartilage at the joint. Treatment with PEA or PEA + luteolin ameliorated the clinical signs at days 26 to 35 and improved histologic status in the joint and paw. The degree of oxidative and nitrosative damage was significantly reduced in PEA + luteolin-treated mice, as indicated by nitrotyrosine and malondialdehyde (MDA) levels. Plasma levels of the proinflammatory cytokines and chemokines were significantly reduced by PEA + luteolin treatment.ConclusionsWe demonstrated that PEA co-ultramicronized with luteolin exerts an antiinflammatory effect during chronic inflammation and ameliorates CIA.  相似文献   
64.
Leveillula on monocotyledonous plants have been recorded as L. taurica by several authors, whereas the fungus on Allium has been described as an independent species, namely L. allii, by some authors. We sequenced ca 600 bp of the rDNA ITS region for two Leveillula specimens from Allium and Polianthes (both from monocotyledons) and compared them with several already published sequences from Leveillula isolates from dicotyledons. Pair-wise percentages of sequence divergences were calculated for all Leveillula isolates. The ITS sequence of the Polianthes isolate was identical to L. taurica on Helianthus and Vicia. The sequence of the Allium isolate was 99.5 % identical to L. taurica on Euphorbia, Haplophylum, Peganum, etc. These results suggest close relationships between monocot and dicot pathogenic Leveillula species. The identity between two monocot isolates was 98.4 %. Phylogenetic analysis revealed that the two monocot isolates do not group into a clade together. This result suggests that Leveillula acquired parasitism to monocots at least twice independently.  相似文献   
65.
The full‐length nucleotide sequence of the Iranian isolate of Eggplant mottled dwarf virus (EMDV), a phytorhabdovirus, was determined using the random polymerase chain reaction method (rPCR) followed by PCR with specific primers to fill in the gaps. The negative‐sense RNA genome of the Iranian isolate of EMDV contains 13154 nucleotides and seven open‐reading frames (ORFs) in the order 3′‐leader‐N‐X‐P‐Y‐M‐G‐L‐trailer‐5′. These ORFs encode the nucleocapsid, X protein (of unknown function), phosphoprotein, Y protein (putative movement protein), matrix protein, glycoprotein and RNA‐dependent RNA polymerase, respectively. EMDV has a 199 nt 3′ leader RNA and a 151 nt 5′ trailer, and the ORFs are separated by conserved intergenic sequences. Phylogenetic analyses indicate that EMDV is most closely related to Potato yellow dwarf virus, which has a distinctly different geographical distribution.  相似文献   
66.

Introduction

The purpose of this study was to evaluate the effects of L-4F, an apolipoprotein A-1 mimetic peptide, alone or with pravastatin, in apoE-/-Fas-/-C57BL/6 mice that spontaneously develop immunoglobulin G (IgG) autoantibodies, glomerulonephritis, osteopenia, and atherosclerotic lesions on a normal chow diet.

Methods

Female mice, starting at eight to nine weeks of age, were treated for 27 weeks with 1) pravastatin, 2) L-4F, 3) L-4F plus pravastatin, or 4) vehicle control, followed by disease phenotype assessment.

Results

In preliminary studies, dysfunctional, proinflammatory high-density lipoproteins (piHDL) were decreased six hours after a single L-4F, but not scrambled L-4F, injection in eight- to nine-week old mice. After 35 weeks, L-4F-treated mice, in the absence/presence of pravastatin, had significantly smaller lymph nodes and glomerular tufts (PL, LP < 0.05), lower serum levels of IgG antibodies to double stranded DNA (dsDNA) (PL < 0.05) and oxidized phospholipids (oxPLs) (PL, LP < 0.005), and elevated total and vertebral bone mineral density (PL, LP < 0.01) compared to vehicle controls. Although all treatment groups presented larger aortic root lesions compared to vehicle controls, enlarged atheromas in combination treatment mice had significantly less infiltrated CD68+ macrophages (PLP < 0.01), significantly increased mean α-actin stained area (PLP < 0.05), and significantly lower levels of circulating markers for atherosclerosis progression, CCL19 (PL, LP < 0.0005) and VCAM-1 (PL < 0.0002).

Conclusions

L-4F treatment, alone or with pravastatin, significantly reduced IgG anti-dsDNA and IgG anti-oxPLs, proteinuria, glomerulonephritis, and osteopenia in a murine lupus model of accelerated atherosclerosis. Despite enlarged aortic lesions, increased smooth muscle content, decreased macrophage infiltration, and decreased pro-atherogenic chemokines in L-4F plus pravastatin treated mice suggest protective mechanisms not only on lupus-like disease, but also on potential plaque remodeling in a murine model of systemic lupus erythematosus (SLE) and accelerated atherosclerosis.  相似文献   
67.
Tamoxifen is an antagonist of the estrogen receptor and currently used for the treatment of breast cancer. The current treatment of cutaneous leishmaniasis with pentavalent antimony compounds is not satisfactory. Therefore, in this study, due to its antileishmanial activity, effects of tamoxifen on the growth of promastigotes and amastigotes of Leishmania major Iranian strain were evaluated in vitro. Promastigotes and amastigotes were treated with different concentrations (1, 5, 10, 20, and 50 μg/ml) and time periods (24, 48, and 72 hr) of tamoxifen. After tamoxifen treatment, MTT assay (3-[4,5-dimethylthiazol-2-yl]-2,5 biphenyl tetrazolium bromide assay) was used to determine the percentage of live parasites and Graph Pad Prism software to calculate IC50. Flow cytometry was applied to investigate the induction of tamoxifen-induced apoptosis in promastigotes. The half maximal inhibitory concentration (IC50) of tamoxifen on promastigotes was 2.6 μg/ml after 24 hr treatment. Flow cytometry analysis showed that tamoxifen induced early and late apoptosis in Leishmania promastigotes. While after 48 hr in control group the apoptosis was 2.0%, the 50 µg/L concentration of tamoxifen increased it to 59.7%. Based on the in vitro antileishmanial effect, tamoxifen might be used for leishmaniasis treatment; however, further researches on in vivo effects of tamoxifen in animal models are needed.  相似文献   
68.
库车种子植物区系垂直分布格局分析   总被引:1,自引:0,他引:1  
该研究通过野外植被调查及相关文献资料查阅,探讨了库车山区种子植物区系的垂直分布格局特征及其对海拔变化的响应。结果表明:该区种子植物约有78科376属960种。其中,裸子植物3科3属9种,被子植物75科373属951种。植物科、属、种总数随着海拔的升高呈现先增加后降低的单峰分布结构。其中科总数在海拔1 600~1 800 m处为最高峰,属总数在海拔1 800~1 900 m处呈现最高峰;物种总数在海拔1 900~2 000 m处呈现最高峰,有478种(隶属59科,230属)。种子植物区系地理成分分析中,库车山区植物区系垂直海拔梯度上不管是科级水平还是属级水平种类成分都以温带分布型占优势。在垂直分布梯度上,温带分布科最高点出现在海拔1 800~1 900 m(含20科),从海拔2 800~2 900 m开始,随着海拔梯度升高呈现下降趋势,到海拔3 600~3 700 m时为最低点(含6科);温带分布属峰值出现在海拔1 900~2 000 m,随着海拔的升高呈现下降趋势。该研究结果对该区植物种质资源和生态系统多样性,植物资源的引种驯化、栽培和合理利用具有重要意义。  相似文献   
69.
在伊朗, 麦扁盾蝽Eurygaster integriceps是小麦和大麦上的主要害虫。新烟碱类杀虫剂是一类具有较强活性的杀虫剂, 对刺吸式口器害虫具有良好的效果。本研究应用触杀和熏蒸两种生测方法测定了4种新烟碱类杀虫剂(噻虫嗪、吡虫啉、呋虫胺和啶虫咪)对麦扁盾蝽3龄若虫和成虫的毒效。触杀法生测结果显示, 各杀虫剂对麦扁盾蝽没有强烈的触杀活性, 但是在高浓度下(5 000 mg/L a. i.), 可见较高的死亡率。熏蒸法生测结果显示, 所有杀虫剂对麦扁盾蝽的若虫和成虫均有较好的毒性。结果提示应用熏蒸方法可能是治理这一重要害虫的新方法。  相似文献   
70.
Abstract

Assessing the amount of released K from minerals in bacterial liquid culture is the main process for screening and isolation of efficient potassium releasing bacteria (KRB). This study was aimed to determine the amount of released K in solution phase or supernatant (SK) as well as microbial biomass K (MBK). Therefore, 20 different bacterial isolates belonging to the 10 bacterial genera (Beijerinckia, Klebsiella, Azotobacter, Pseudomonas, Agrobacterium, Rhizobium, Sphingomonas, Citrobacter, Microbacterium, and Achromobacter) were individually used to inoculate Aleksandrov medium in presence of biotite or muscovite. Our results from in-vitro experiments revealed that the MBK (K in pellet) is more important than in SK. Although some genera such as Azotobacter and Citrobacter released more SK (16?mg/l from biotite and 12.77?mg/l from muscovite, respectively), the Klebsiella isolates with the highest MBK could release an average of 90?mg/l total K. This study indicated that the assimilated K in microbial cells is the main part of K dissolution from minerals. Due to the fast turnover of nutrients in bacterial biomass, it can be concluded that both SK and MBK could be available for plants. It seems that the finding of this research should be considered in the isolation of KRB.

Highlights

  • This study reports, assessment of soluble and biomass K in the culture medium is a reliable tool for estimation of K releasing efficiency of bacteria

  • Our results from in vitro experiments revealed that the assimilated K in microbial cells is the main part of K dissolved from minerals.

  • Although some genera such as Azotobacter released more K in solution phase, the Klebsiella isolates with the highest biomass K could release more total K

  相似文献   
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