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71.
Alien species are brought into countries world wide on a massive scale for agricultural production, ex situ conservation, landscape aesthetics, gardens, and ecosystem restoration. Unfortunately, some of these species have escaped and adversely impacted on regional as well as global biodiversity conservation and agricultural production. To reduce such risks, it is necessary to implement specific and effective measures. Since various government departments and institutions are involved in the management of alien species, it is difficult to prevent native and agroecosystems from being invaded by invited species. We propose the establishment of a supervision and inspection continuum over intentional species introduction, similar to that which exists in some countries over unintentional species introductions. Namely, a justification of the necessity to import, a risk assessment, assurances as to provision of an adequate containment facility assessment, and a damage-limitation protocol should that need to be invoked. These requirements should be satisfied before an alien species is knowingly imported, and the necessary follow-up supervision is important post- importation.  相似文献   
72.
运用双向聚丙烯酰胺凝胶电泳(2DPAGE)分析未交配小鼠子宫内膜和妊娠第五天(D5)小鼠子宫内膜胚泡黏附时植入位点及其旁组织蛋白质组。差异蛋白质组学显示,等电点(isoelectric point,pI)约7.1、分子量(molecular weight,Mw)约18kDa的蛋白质点在D5小鼠子宫内膜特别是植入位点表达上调。对此蛋白质点用基质辅助激光解析电离飞行时间质谱(matrix-assisted laser desorption/ionization time of flying mass spectrometry,MALDI—TOF—MS)测定其胶内酶解后的肽质量指纹谱(Peptide Mass Fingerprint,PMF),经Mascot:Peptide Mass Fingerprint中SWISS-PROT数据库查询后,鉴定该蛋白质为鼠源性nm23-M2/NDPKB。RT—PCR和免疫组织化学结果也显示D5小鼠子宫内膜nm23-M2/NDPK B mRNA和蛋白表达明显增加。提示nm23-M2/NDPKB参与胚泡着床这一重要生命活动过程。  相似文献   
73.
Among the antimicrobial molecules produced by epithelial cells, DEFB4 is inducible in response to proinflammatory signals such as cytokines and bacterial molecules. Nontypeable Haemophilus influenzae (NTHi) is an important human pathogen that exacerbates chronic obstructive pulmonary disease in adult and causes otitis media and sinusitis in children. Previously, we have demonstrated that DEFB4 effectively kills NTHi and is induced by NTHi via TLR2 signaling. The 5′-flanking region of DEFB4 contains several NF-κB binding motifs, but their NTHi-specific activity remains unclear. In this study, we aimed to elucidate molecular mechanism involved in DEFB4 regulation, focusing on the role of the distal NF-κB binding motif of DEFB4 responding to NTHi. Here, we show that the human middle ear epithelial cells up-regulate DEFB4 expression in response to NTHi via NF-κB activation mediated by IκKα/β−IκBα signaling. Deletion of the distal NF-κB binding motif led to a significant reduction in NTHi-induced DEFB4 up-regulation. A heterologous construct containing the distal NF-κB binding motif was found to increase the promoter activity in response to NTHi, indicating a NTHi-responding enhancer activity of the distal NF-κB binding motif. Furthermore, electrophoretic mobility shift assays and chromatin immunoprecipitation assays showed that the p65 domain of NF-κB binds to the distal NF-κB binding motif in response to NTHi. Taken together, our results suggest that NTHi-induced binding of p65 NF-κB to the distal NF-κB binding motif of DEFB4 enhances NTHi-induced DEFB4 regulation in epithelial cells.  相似文献   
74.
Forest regrowth after cropland abandonment and urban sprawl are two counteracting processes that have influenced carbon (C) sequestration in the southeastern United States in recent decades. In this study, we examined patterns of land-use/land-cover change and their effect on ecosystem C storage in three west Georgia counties (Muscogee, Harris, and Meriwether) that form a rural–urban gradient. Using time series Landsat imagery data including MSS for 1974, TM for 1983 and 1991, and ETM for 2002, we estimate that from 1974 to 2002, urban land use in the area has increased more than 380% (that is, 184 km2). Most newly urbanized land (63%) has been converted from forestland. Conversely, cropland and pasture area has decreased by over 59% (that is, 380 km2). Most of the cropland area was converted to forest. As a result, the net change in forest area was small over the past 29 years. Based on Landsat imagery and agricultural census records, we reconstructed an annual gridded data set of land-cover change for the three counties for the period 1850 to 2002. These data sets were then used as input to the Terrestrial Ecosystem Model (TEM) to simulate land-use effects on C fluxes and storage for the study area. Simulated results suggest that C uptake by forest regrowth (approximately 23.0 g C m−2 y−1) was slightly greater than the amount of C released due to deforestation (approximately 18.4 g C m−2 y−1), thus making the three counties a weak C sink. However, the relative importance of different deforestation processes in this area changed significantly through time. Although agricultural deforestation was generally the most important C-release process, the amount of C release attributable to urbanization has increased over time. Since 1990, urbanization has accounted for 29% of total C loss from the study area. We conclude that balancing urban development and forest protection is critically important for C management and policy making in the southeastern United States.  相似文献   
75.
76.
Guo P  Su Y  Cheng Q  Pan Q  Li H 《Carbohydrate research》2011,(7):986-990
The 1:1 inclusion complex of β-cyclodextrin and p-aminobenzoic acid was prepared and characterized by TG-DTA. The crystal structure of the complex was solved directly from powder X-ray diffraction data using the direct space approach and refined using Rietveld refinement techniques. The complex crystallizes in monoclinic P21 space group, with unit cell parameters a = 20.7890 ?, b = 10.2084 ?, c = 15.1091 ?, β = 110.825°, V = 2997 ?3. The amino group is located at the wide side of the β-cyclodextrin cavity, forming hydrogen bonds with β-cyclodextrin, and the carboxyl group is located at the narrow side. The crystallographic data obtained from powder diffraction data were compared with the single crystallographic data, and the result shows that solving crystal structure of cyclodextrins inclusion complexes of such complexity is accessible to powder diffractionists to some extent.  相似文献   
77.
Trehalose synthase converts glycogen to trehalose   总被引:2,自引:0,他引:2  
Trehalose (alpha,alpha-1,1-glucosyl-glucose) is essential for the growth of mycobacteria, and these organisms have three different pathways that can produce trehalose. One pathway involves the enzyme described in the present study, trehalose synthase (TreS), which interconverts trehalose and maltose. We show that TreS from Mycobacterium smegmatis, as well as recombinant TreS produced in Escherichia coli, has amylase activity in addition to the maltose <--> trehalose interconverting activity (referred to as MTase). Both activities were present in the enzyme purified to apparent homogeneity from extracts of Mycobacterium smegmatis, and also in the recombinant enzyme produced in E. coli from either the M. smegmatis or the Mycobacterium tuberculosis gene. Furthermore, when either purified or recombinant TreS was chromatographed on a Sephacryl S-200 column, both MTase and amylase activities were present in the same fractions across the peak, and the ratio of these two activities remained constant in these fractions. In addition, crystals of TreS also contained both amylase and MTase activities. TreS produced both radioactive maltose and radioactive trehalose when incubated with [(3)H]glycogen, and also converted maltooligosaccharides, such as maltoheptaose, to both maltose and trehalose. The amylase activity was stimulated by addition of Ca(2+), but this cation inhibited the MTase activity. In addition, MTase activity, but not amylase activity, was strongly inhibited, and in a competitive manner, by validoxylamine. On the other hand, amylase, but not MTase activity, was inhibited by the known transition-state amylase inhibitor, acarbose, suggesting the possibility of two different active sites. Our data suggest that TreS represents another pathway for the production of trehalose from glycogen, involving maltose as an intermediate. In addition, the wild-type organism or mutants blocked in other trehalose biosynthetic pathways, but still having active TreS, accumulate 10- to 20-fold more glycogen when grown in high concentrations (> or = 2% or more) of trehalose, but not in glucose or other sugars. Furthermore, trehalose mutants that are missing TreS do not accumulate glycogen in high concentrations of trehalose or other sugars. These data indicate that trehalose and TreS are both involved in the production of glycogen, and that the metabolism of trehalose and glycogen is interconnected.  相似文献   
78.
The angiosomes of the head and neck: anatomic study and clinical applications   总被引:14,自引:0,他引:14  
The angiosome concept was introduced over a decade ago by Taylor and Palmer, whereby the body was considered to be composed anatomically of multiple three-dimensional composite blocks of tissue supplied by particular source arteries. Since then, detailed studies of the forearm and leg have been examined by Taylor and his coworkers. This study focuses on another region--the head and neck. Six fresh head and neck cadaver specimens were examined after infusion with a radio-opaque lead oxide mixture and correlated with over 24 previous body studies. The vascular anatomy of the skin, superficial musculoaponeurotic system (SMAS), muscles, brain, dura, and bone was examined. Each layer was painstakingly removed, photographed, labeled, and mapped to the respective arteries and veins. A radiologic subtraction technique was used to allow successive layers to be compared. This information was then scanned into a computer, analyzed, color coded, and labeled, thereby producing a three-dimensional study of the head and neck region to identify the respective angiosomes. As in previous detailed examinations of the leg and forearm, the angiosomes were found to be connected usually within tissues, such as muscle, skin, specialized organs or glands, rather than between the tissues. The muscles usually had vessels of two or more angiosomes supplying them and fell into three major groups based on the similarity of their arterial supply. In some areas, the midline anastomoses were rich, especially in the integument of the scalp, forehead, and lips. In other regions, the midline vascular connections were poor, especially in the tongue and palate. No fewer than 13 angiosomes of the head and neck, supplied by the branches of the external carotid, internal carotid, and subclavian arteries, have been defined, mapping their three-dimensional territories in the skin, the deep soft tissues, and the bones. Although most angiosomes spanned between skin and bone, three territories, those of the vertebral, lingual, and ascending pharyngeal vessels, were confined to the deep tissues without cutaneous representation. Finally, this study provides additional data for the surgeon to help plan safer incisions and better reconstructive flap procedures. It also gives information that may help explain the etiology and treatment of head and neck arteriovenous vascular malformations.  相似文献   
79.
Eimeria acervulina 3-1E antigen gene and mature chicken interleukin 15 (mChIL-15) gene were cloned into expression vector pcDNA3.1(+) in different forms, produced DNA vaccine pcDNA3.1-3-1E, and pcDNA3.1-3-1E-linker-mChIL-15 co-expressing E. acervulina 3-1E gene and mChIL-15 gene, respectively. The expression of objective gene in vitro was detected by indirect fluorescent antibody technique and immunohistochemistry. The two DNA vaccines were administered by intramuscular leg injection. An animal challenge experiment was carried out to evaluate the immune protective efficacy of the vaccines. The results indicated that DNA vaccines were successfully constructed and the expression of objective gene could be detected in vitro. The animal experimental results showed that both DNA vaccines could provide partial protection against homologous challenge in chickens. The chimeric DNA vaccine, pcDNA3.1-3-1E-linker-mChIL-15, could significantly increase oocyst decrease ratio, reduce the average lesion score in the duodenum, improve body weight gain, and increase anti-coccidial index (ACI) compared to the DNA vaccine pcDNA3.1-3-1E. Taken together, these results demonstrate ChIL-15 enhance the immunogenicity of 3-1E DNA vaccine, and co-expression of cytokine and optimized surface antigen of Eimeria may be a promising method to enhance immunogenicity of DNA vaccines in poultry.  相似文献   
80.
中药柴胡不同采收期的皂甙含量   总被引:4,自引:0,他引:4  
中药柴胡不同采收期的皂甙含量潘泽惠庄体德周雪林林湘(江苏省中国科学院植物研究所,南京210014)(黑龙江双鸭山矿务局师范学校,双鸭山155125)OnseasonalchangesofthetotalsaponinsinChinesetradit...  相似文献   
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