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51.
Muhammad Zubair Asghar Aurangzeb Khan Shakeel Ahmad Imran Ali Khan Fazal Masud Kundi 《PloS one》2015,10(10)
The exponential increase in the explosion of Web-based user generated reviews has resulted in the emergence of Opinion Mining (OM) applications for analyzing the users’ opinions toward products, services, and policies. The polarity lexicons often play a pivotal role in the OM, indicating the positivity and negativity of a term along with the numeric score. However, the commonly available domain independent lexicons are not an optimal choice for all of the domains within the OM applications. The aforementioned is due to the fact that the polarity of a term changes from one domain to other and such lexicons do not contain the correct polarity of a term for every domain. In this work, we focus on the problem of adapting a domain dependent polarity lexicon from set of labeled user reviews and domain independent lexicon to propose a unified learning framework based on the information theory concepts that can assign the terms with correct polarity (+ive, -ive) scores. The benchmarking on three datasets (car, hotel, and drug reviews) shows that our approach improves the performance of the polarity classification by achieving higher accuracy. Moreover, using the derived domain dependent lexicon changed the polarity of terms, and the experimental results show that our approach is more effective than the base line methods. 相似文献
52.
Aenasius bambawalei (Hymenoptera: Encyrtidae) is a koinobiont nymphal endoparasitoid of cotton mealybug, Phenacoccus solenopsis (Hemiptera: Pseudocccidae). Functional analysis of the venom of the wasp was performed by artificial microinjections of both crude and treated venom (heat and proteinase) of the wasp containing 0.3 and 0.5 μl in non-parasitized and synchronized adult hosts (mealybugs) and the mortality data were recorded 24, 48, 72 and 96 hours post injecton while mealybugs receiving saline injections were acted as control. The main effects for artificially envenomated mealybugs were observed on their mortality and survival. The biological activity of crude venom was also evaluated by heat and protease treatment. Here, we demonstrate that maximum mortality (82 ± 2.0%) was achieved by microinjections containing higher volume (0.5 μl) of crude venom while lower mortality (68 ± 4.0%) was achieved with lower volume of venom (0.3 μl). On the other hand, heat and proteinase K treated venom did not show any significant effect on mortality of the host insect. Our findings suggest that bioactive components of the crude venom are proteins which lost their activity upon heat and protease treatment. This basic information regarding the functional role of the venom of A. bambawalei serves as a starting point for comprehensive analysis of the role of the venom of the parasitoid on the regulation processes in its host. 相似文献
53.
Riaz Ur Rehman Muhammad Fayyaz Chaudhary Khalid Mahmood Khawar Gang Lu Abdul Mannan Muhammad Zia 《Biologia》2014,69(3):341-349
Present study describes rapid in vitro propagation of Caralluma tuberculata, a traditional medicinal plant, and antioxidant potential of calli and plants extracts. The highest callus induction rate (93.3%) with maximum weight of calli 5.2 g was achieved from shoot tip explants on MS medium supplemented with 9.04 μM 2,4-D and 4.44 μM BA. The maximum shoot induction rate (71.1%) with mean number of shoots 3.66 ± 1.53 and 4.6 cm average shoot length was observed on 13.32 μM BA, 4.52 μM 2,4-D and 2.89 μM GA3 appended in MS medium. The developed shoots were best rooted in the presence of 5.07 μM IAA with 3.0 ± 0.15 roots per plantlet. The plants were successfully acclimatized under in vivo conditions. The plants and calli extracts exhibited good antioxidant activities, however, plant extract activities were more pronounced. The phenolic compounds in plant and calli extracts were 0.16% and 0.057%, respectively. While the flavonoids were 0.092% in plant and 0.039% in calli extract. Total Phenolics, flavonoids; DPPH radical scavenging activity and reducing power potential distributed among different fractions depending upon polarity of the solvent. The highest DPPH scavenging activity and reducing power was exhibited by water fractions; 4.95 mg/mL and 0.729 OD at 10 mg/mL, respectively. The micropropagation protocol can be successfully used for large-scale multiplication and conservation of germplasm of this threatened plant. Furthermore, antioxidant value describes importance of this valuable plant as food and medicine. 相似文献
54.
Iain D. Hay Zahid U. Rehman Bernd H. A. Rehm 《Applied and environmental microbiology》2010,76(6):1806-1812
The ubiquitous opportunistic human pathogen Pseudomonas aeruginosa secretes a viscous extracellular polysaccharide, called alginate, as a virulence factor during chronic infection of patients with cystic fibrosis. In the present study, it was demonstrated that the outer membrane protein AlgE is required for the production of alginate in P. aeruginosa. An isogenic marker-free algE deletion mutant was constructed. This strain was incapable of producing alginate but did secrete alginate degradation products, indicating that polymerization occurs but that the alginate chain is subsequently degraded during transit through the periplasm. Alginate production was restored by introducing the algE gene. The membrane topology of the outer membrane protein AlgE was assessed by site-specific insertions of FLAG epitopes into predicted extracellular loop regions.Pseudomonas aeruginosa is an ubiquitous opportunistic human pathogen responsible for chronic infections of the lungs of patients with cystic fibrosis (CF), in whom it is the leading cause of mortality and morbidity (9). The establishment of a chronic infection in the lungs of patients with CF coincides with the switch of P. aeruginosa to a stable mucoid variant, producing copious amounts of the exopolysaccharide alginate; this is typically a poor prognostic indicator for these patients (24, 31). Alginate is a linear unbranched exopolysaccharide consisting of 1,4-linked monomers of β-d-mannuronic acid and its C-5 epimer, α-l-guluronic acid, which is known to be produced by only two bacterial genera, Pseudomonas and Azotobacter (34). The switch to a mucoid phenotype coincides with the appearance of a 54-kDa protein in the outer membrane; this protein has been identified and has been designated AlgE (13, 31).The genes encoding the alginate biosynthesis machinery are located within a 12-gene operon (algD-alg8-alg44-algK-algE-algG-algX-algL-algI-algJ-algF-algA). AlgA and AlgD, along with AlgC (not encoded in the operon), are involved in precursor synthesis (34). Alg8 is the catalytic subunit of the alginate polymerase located at the inner membrane (35). AlgG is a C-5 mannuronan epimerase (19). AlgK contains four putative Sel1-like repeats, similar to the tetratricopeptide repeat motif often found in adaptor proteins involved in the assembly of multiprotein complexes (3, 10). AlgX shows little homology to any known protein, and its role is unclear (14). Knockout mutants of AlgK, AlgG, and AlgX have nonmucoid phenotypes, although they produce short alginate fragments, due to the activity of the alginate lyase (AlgL), which degrades the nascent alginate (1, 14, 19-21, 36). AlgF, AlgI, and AlgJ are involved in acetylation of alginate, but they are not ultimately required for its production (12). The membrane-anchored protein, Alg44, is required for polymerization and has a PilZ domain for the binding of c-di-GMP, a secondary messenger essential for alginate production (16, 25, 33). The periplasmic C terminus of Alg44 shares homology with the membrane fusion proteins involved in the bridging of the periplasm in multidrug efflux pumps (11, 43). The periplasmic alginate lyase, AlgL, appears to be required for the translocation of intact alginate across the periplasm (1, 26). AlgE is an outer membrane, anion-selective channel protein through which alginate is presumably secreted (30). A protein complex or scaffold through which the alginate chain can pass and be modified and which spans the periplasm bridging the polymerase located (Alg8) at the outer membrane pore (AlgE) has been proposed (21). Indeed, it has been demonstrated that both the inner and the outer membranes are required for the in vitro polymerization of alginate (35).The requirement of AlgE for the biosynthesis of alginate in P. aeruginosa was first observed by complementation of an alginate-negative mutant derived by chemical mutagenesis with a DNA fragment containing algE (8) Secondary structure predictions suggested that AlgE forms an 18-stranded β barrel with extended extracellular loops. Several of these loops show high densities of charged amino acids, suggesting a functional role in the translocation of the anionic alginate polymer (29, 30). Preliminary analysis of AlgE crystals has been reported (48).In this study, the role of AlgE in alginate biosynthesis was investigated and the membrane topology of AlgE was assessed by site-directed insertion mutagenesis. 相似文献
55.
Kaimian Li Wenli Zhu Kang Zeng Zhenwen Zhang Jianqiu Ye Wenjun Ou Samrina Rehman Bruria Heuer Songbi Chen 《Proteome science》2010,8(1):10
Background
Proteomics is increasingly becoming an important tool for the study of many different aspects of plant functions, such as investigating the molecular processes underlying in plant physiology, development, differentiation and their interaction with the environments. To investigate the cassava (Manihot esculenta Crantz) proteome, we extracted proteins from somatic embryos, plantlets and tuberous roots of cultivar SC8 and separated them by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). 相似文献56.
Biosurfactant production by Pseudomonas aeruginosa EBN-8 mutant was studied in shake flasks on separate wastes from canola, soybean and corn oil refineries. Of the substrates
tested, canola oil refinery waste (COD=20 g l−1) supplemented with sodium nitrate (at COD/N=20) showed the best microbial growth (4.50 g l−1) and rhamnolipid production (8.50 g l−1), at 10 d of incubation with the specific growth rate of 0.316 h−1 and specific product yield of 0.597 g g−1 h. Its cell-free supernatant showed the critical micelle dilution (CMD) of 150 and surface tension (ST) of 28.5 mN m−1. 相似文献
57.
Ott SJ El Mokhtari NE Rehman A Rosenstiel P Hellmig S Kühbacher T Lins M Simon R Schreiber S 《Environmental microbiology》2007,9(12):3035-3045
Bacterial DNA has been found in coronary plaques and it has therefore been concluded that bacteria may play a role as trigger factors in the chronic inflammatory process underlying coronary atherosclerosis. However, the microbial spectrum is complex and it is not known whether microorganisms other than bacteria are involved in coronary disease. Fungal 18S rDNA signatures were systematically investigated in atherosclerotic tissue obtained through catheter-based atherectomy of 38 patients and controls (unaffected coronary arteries) using clone libraries, denaturating gradient gel analysis (DGGE), in situ hybridization and fluorescence in situ hybridization (FISH). Fungal DNA was found in 35 of 38 (92.11%) coronary heart disease patients by either polymerase chain reaction (PCR) with universal primers or in situ hybridization analysis (n = 5), but not in any control sample. In a clone library with more than 350 sequenced clones from pooled patient DNA, an overall richness of 19 different fungal phylotypes could be observed. Fungal profiles of coronary heart disease patients obtained by DGGE analysis showed a median richness of fungal species of 5 (range from 2 to 9) with a high interindividual variability (mean similarity 18.83%). For the first time, the presence of fungal components in atherosclerotic plaques has been demonstrated. Coronary atheromatous plaques harbour diverse and variable fungal communities suggesting a polymicrobial contribution to the chronic inflammatory aetiology. 相似文献
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60.
Aysha H Khan Muniba Aban Jamal Raza Naeem ul Haq Abdul Jabbar Tariq Moatter 《BMC endocrine disorders》2011,11(1):1-6