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681.
Dominance of individual plant species is more important than diversity in explaining plant biomass in the forest understorey 总被引:2,自引:0,他引:2 下载免费PDF全文
682.
Study of bioaerosols and site influence in the La Plata area (Argentina) using conventional and DNA (fingerprint) based methods 总被引:1,自引:0,他引:1
The present study approaches the characterization of seasonal samples of bioaerosols taken during 2005–2006 in rural, urban,
industrial, coastal and residential sites within La Plata area, Buenos Aires, Argentina. Culturable airborne fungal and bacterial
communities were collected on DG18 agar and R2 Agar plates respectively, using a single-stage SKC sampling device. Fungal
genera were identified based on their micro- and macro-morphological characteristics. Bacterial populations were analyzed
by denaturing gradient gel electrophoresis (DGGE) of PCR 16SrDNA bacterial amplification. Geometric mean concentration of
bacteria and fungi ranged from 10 to 103 CFU m−3 and were comparable with those from other reports. No differences were observed among sites for fungi and Cladosporium sp. was predominant, with 85.7% of total concentration counts; secondary genera that contributed were Alternaria (6.7%), Penicillium (1.8%), Aspergillus (1.3%), Epicoccum (1.0%) and the group of yeasts (1.9%). The dominance of Cladosporium in all sites suggests that the most abundant fungal aerosol was neither significantly affected nor primarily generated by
any anthropogenic area source more than the natural ambience present in the La Plata area. With regard to bacteria, the results
showed on several occasions differences in concentration among sites during sampling events, but these differences were not
observed when the community structure was analyzed by means of DGGE. Bacterial DGGE banding profiles from all sites revealed
the existence of a relatively diversified, culture-based airborne community. Construction of similarity dendrograms exposed
a distribution of site samples in which replicates intra-site equalled those encountered among sites, rendering substantial
inference of site distinction unfeasible. 相似文献
683.
This study evaluates the effectiveness of three different molecular techniques, repetitive extragenic palindromic PCR (REP-PCR), enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR) and the random amplified polymorphic DNA (RAPD-PCR) for rapid typing of Photobacterium damselae ssp. piscicida strains isolated from different species of marine fish and geographic areas. The results obtained by the three methods showed that RAPD and ERIC-PCR were more discriminative for suitable rapid typing of Ph. damselae ssp. piscicida than REP-PCR. The analysis of DNA banding patterns generated by both molecular methods (RAPD and ERIC-PCR) clearly separated the strains into two main groups that strongly correlated with their geographic origin. Moreover, the REP-PCR analysis was less reproducible than the RAPD and ERIC-PCR methods and does not allow the establishment of genetic groups. RAPD and ERIC-PCR constitute valuable tools for molecular typing of Ph. damselae ssp. piscicida strains, which can be used in epidemiological studies of photobacteriosis infections. 相似文献
684.
A recombinant functional variant of the olive pollen allergen Ole e 10 expressed in baculovirus system 总被引:2,自引:0,他引:2
Barral P Serrano AG Batanero E Pérez-Gil J Villalba M Rodríguez R 《Journal of biotechnology》2006,121(3):402-409
Pollens have been reported as important sources of antigens causing type-I allergy and, among them, olive pollen has high clinical relevance in Mediterranean countries. The most recently described olive allergen, Ole e 10, is involved in cross-reactivity phenomena and related to asthma induction in allergic patients. These immunologic features make this allergen a good candidate to be included in diagnosis and therapy of protocols of allergic diseases. Since the availability of Ole e 10 from the olive pollen is limited, the allergen has been efficiently expressed in the baculovirus/insect cell system. The Ole e 10-cDNA inserted into the transfer vector pBacPAK8 allowed the expression of the recombinant protein in cultured Sf21 cells. Recombinant Ole e 10 (rOle e 10) was purified from the culture after dialysis and three chromatographic steps. Mass spectrometry, Edman degradation, IgE- and IgG-binding analyses were employed to characterize the recombinant allergen, which showed molecular and immunological equivalence with the natural protein. Affinity gel electrophoresis in presence of laminarin (1,3-beta-glucan) revealed that rOle e 10 retains identical carbohydrate-binding capacity than the natural allergen. In conclusion, the recombinant expression of Ole e 10 in baculovirus/insect cell system produces a homogeneous and biologically active allergen that could be useful for clinical and scientific purposes. 相似文献
685.
Life cycle assessment (LCA) is a promising tool in the pursuit of sustainable mining. However, the accounting methodologies used in LCA for abiotic resource depletion still have some shortcomings and need to be improved. In this article a new thermodynamic approach is presented for the evaluation of the depletion of nonfuel minerals. The method is based on quantifying the exergy costs required to replace the extracted minerals with current available technologies, from a completely degraded state in what we term “Thanatia” to the conditions currently found in nature. Thanatia is an estimated reference model of a commercial end of the planet, where all resources have been extracted and dispersed, and all fossil fuels have been burned. Mineral deposits constitute an exergy bonus that nature gives us for free by providing minerals in a concentrated state and not dispersed in the crust. The exergy replacement costs provide a measure of the bonus lost through extraction. This approach allows performing an LCA by including a new stage in the analysis: namely the grave to cradle path. The methodology is explained through the case study of nickel depletion. 相似文献
686.
Litterfall and leaf decomposition rates were measured in Choui Island, 45 km downstream from the confluence of the Paraná and Paraguay rivers. The material was collected biweekly from April 1985 through September 1986. Decomposition was measured in situ by the litter bag technique.Annual litterfall of Tessaria integrifolia gallery forest measured in the period April 1985 to March 1986 was 8.15 t ha-1. Leaf litterfall was seasonal, i.e. significantly less leaf litter was shed during the high water phase than during the low water phase. The half life of the T. integrifolia litter over 38 days of decomposition was 20 days. At the beginning of the experiment, 15 and 38 days subsamples of remaining detritus were analyzed in order to determine changes in the nutrient content. After 38 days of incubation, the order of nutrient disappearance was Ca > K > N > Mg > Na > P.The number of invertebrates per g remaining litter of Tessaria integrifolia increased between incubations days 7 and 31. Collector-gatherers were more abundant after 38 days incubation; there were no shredders colonizing the leaf litter bags. 相似文献
687.
Hariri S Steinau M Rinas A Gargano JW Ludema C Unger ER Carter AL Grant KL Bamberg M McDermott JE Markowitz LE Brewer NT Smith JS 《PloS one》2012,7(3):e34044
Background
HPV typing using formalin fixed paraffin embedded (FFPE) cervical tissue is used to evaluate HPV vaccine impact, but DNA yield and quality in FFPE specimens can negatively affect test results. This study aimed to evaluate 2 commercial assays for HPV detection and typing using FFPE cervical specimens.Methods
Four large North Carolina pathology laboratories provided FFPE specimens from 299 women ages18 and older diagnosed with cervical disease from 2001 to 2006. For each woman, one diagnostic block was selected and unstained serial sections were prepared for DNA typing. Extracts from samples with residual lesion were used to detect and type HPV using parallel and serial testing algorithms with the Linear Array and LiPA HPV genotyping assays.Findings
LA and LiPA concordance was 0.61 for detecting any high-risk (HR) and 0.20 for detecting any low-risk (LR) types, with significant differences in marginal proportions for HPV16, 51, 52, and any HR types. Discordant results were most often LiPA-positive, LA-negative. The parallel algorithm yielded the highest prevalence of any HPV type (95.7%). HR type prevalence was similar using parallel (93.1%) and serial (92.1%) approaches. HPV16, 33, and 52 prevalence was slightly lower using the serial algorithm, but the median number of HR types per woman (1) did not differ by algorithm. Using the serial algorithm, HPV DNA was detected in >85% of invasive and >95% of pre-invasive lesions. The most common type was HPV16, followed by 52, 18, 31, 33, and 35; HPV16/18 was detected in 56.5% of specimens. Multiple HPV types were more common in lower grade lesions.Conclusions
We developed an efficient algorithm for testing and reporting results of two commercial assays for HPV detection and typing in FFPE specimens, and describe HPV type distribution in pre-invasive and invasive cervical lesions in a state-based sample prior to HPV vaccine introduction. 相似文献688.
Duncan J. Campbell Jithendra B. Somaratne Alicia J. Jenkins David L. Prior Michael Yii James F. Kenny Andrew E. Newcomb Casper G. Schalkwijk Mary Jane Black Darren J. Kelly 《PloS one》2012,7(11)
Background
Heart failure is associated with abnormalities of myocardial structure, and plasma levels of the advanced glycation end-product (AGE) Nε-(carboxymethyl)lysine (CML) correlate with the severity and prognosis of heart failure. Aging is associated with diastolic dysfunction and increased risk of heart failure, and we investigated the hypothesis that diastolic dysfunction of aging humans is associated with altered myocardial structure and plasma AGE levels.Methods
We performed histological analysis of non-ischemic left ventricular myocardial biopsies and measured plasma levels of the AGEs CML and low molecular weight fluorophores (LMWFs) in 26 men undergoing coronary artery bypass graft surgery who had transthoracic echocardiography before surgery. None had previous cardiac surgery, myocardial infarction, atrial fibrillation, or heart failure.Results
The patients were aged 43–78 years and increasing age was associated with echocardiographic indices of diastolic dysfunction, with higher mitral Doppler flow velocity A wave (r = 0.50, P = 0.02), lower mitral E/A wave ratio (r = 0.64, P = 0.001), longer mitral valve deceleration time (r = 0.42, P = 0.03) and lower early diastolic peak velocity of the mitral septal annulus, e’ (r = 0.55, P = 0.008). However, neither mitral E/A ratio nor mitral septal e’ was correlated with myocardial total, interstitial or perivascular fibrosis (picrosirius red), immunostaining for collagens I and III, CML, and receptor for AGEs (RAGE), cardiomyocyte width, capillary length density, diffusion radius or arteriolar dimensions. Plasma AGE levels were not associated with age. However, plasma CML levels were associated with E/A ratio (r = 0.44, P = 0.04) and e’ (r = 0.51, P = 0.02) and LMWF levels were associated with E/A ratio (r = 0.49, P = 0.02). Moreover, the mitral E/A ratio remained correlated with plasma LMWF levels in all patients (P = 0.04) and the mitral septal e’ remained correlated with plasma CML levels in non-diabetic patients (P = 0.007) when age was a covariate.Conclusions
Diastolic dysfunction of aging was independent of myocardial structure but was associated with plasma AGE levels. 相似文献689.
ICC pacing mechanisms in intact mouse intestine differ from those in cultured or dissected intestine
Boddy G Bong A Cho W Daniel EE 《American journal of physiology. Gastrointestinal and liver physiology》2004,286(4):G653-G662
Pacing of mouse intestine is driven by spontaneous activity of a network of interstitial cells of Cajal in the myenteric plexus (ICC-MP). So far, highly dissected circular muscle (CM) strips from control and mutant mice lacking ICC-MP and isolated, cultured ICC from newborn control mice were used to analyze its properties. Using intact circular and longitudinal segments of intestine, we recently reported that there were both significant similarities and differences between pacing studied in segments and from isolated, dissected tissues. Here, we report additional similarities and differences in our model from those in highly reduced systems. Similar to cultured or dissected intestine, blockade of sarcoplasmic-endoplasmic reticulum Ca(2+) pumps with thapsigargin or cyclopiazonic acid reduced pacing frequency, but thapsigargin was less effective than in isolated, cultured ICC. Moreover, inhibition of inositol 1,4,5-trisphosphate (IP(3)) receptors with xestospongin C, a putative inhibitor of IP(3) receptors, failed to affect pacing but successfully blocked increased pacing frequency by phorbol ester. 2-Aminoethoxy-diphenylborate, a putative blocker of IP(3)-mediated calcium release, caused a significant decrease in the amplitude and frequency of contractions. The mitochondrial uncoupler carbonyl cyanide p-trifluormethoxyphenylhydrazone blocked pacing and KCl-induced contractions at a concentration of 1 microM. The cyclic nucleotide agonists sodium nitroprusside (SNP), forskolin, and 8-bromo-cGMP inhibited pacing in CM. In longitudinal muscle (LM), SNP and forskolin had little effect on pacing. Furthermore, dibutyryl-cAMP did not affect pacing in CM or LM. These results suggest that pacing in intact intestine is under partly similar regulatory control as in more reduced systems. However, pacing in intact intestine is not affected by xestospongin C, which abolishes pacing in isolated, cultured ICC and exhibits attenuated responses to thapsigargin. Also, major differences between LM and CM suggest a separate pacemaker may drive LM. 相似文献
690.
Pavani K. Ram Margaret A. DiVita Kaniz Khatun-e-Jannat Manoshi Islam Kimberly Krytus Emily Cercone Badrul Munir Sohel Makhdum Ahmed Abid Mahmud Quaiyum Rahman Mustafizur Rahman Jihnhee Yu W. Abdullah Brooks Eduardo Azziz-Baumgartner Alicia M. Fry Stephen P. Luby 《PloS one》2015,10(6)