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121.
Jane Vishnevetsky Thomas L. White Jr. Aaron J. Palmateer Moshe Flaishman Yuval Cohen Yigal Elad Margarita Velcheva Uri Hanania Nachman Sahar Oded Dgani Avihai Perl 《Transgenic research》2011,20(1):61-72
The most devastating disease currently threatening to destroy the banana industry worldwide is undoubtedly Sigatoka Leaf spot disease caused by Mycosphaerella fijiensis. In this study, we developed a transformation system for banana and expressed the endochitinase gene ThEn-42 from Trichoderma harzianum together with the grape stilbene synthase (StSy) gene in transgenic banana plants under the control of the 35S promoter and the inducible PR-10 promoter, respectively. The superoxide dismutase gene Cu,Zn-SOD from tomato, under control of the ubiquitin promoter, was added to this cassette to improve scavenging of free radicals generated during fungal attack. A 4-year field trial demonstrated several transgenic banana lines with improved tolerance to Sigatoka. As the genes conferring Sigatoka tolerance may have a wide range of anti-fungal activities we also inoculated the regenerated banana plants with Botrytis cinerea. The best transgenic lines exhibiting Sigatoka tolerance were also found to have tolerance to B. cinerea in laboratory assays. 相似文献
122.
Lachaise F Martin G Drougard C Perl A Vuillaume M Wegnez M Sarasin A Daya-Grosjean L 《Free radical biology & medicine》2001,30(12):1365-1373
123.
Natália H Mendes Fernando AF Melo Adolfo CB Santos José RC Pandolfi Elisabete A Almeida Rosilene F Cardoso Henri Berghs Suzana David Faber K Johansen Lívia G Espanha Sergio RA Leite Clarice QF Leite 《BMC research notes》2011,4(1):269
Background
Tuberculosis is a major health problem in São Paulo, Brazil, which is the most populous and one of the most cosmopolitan cities in South America. To characterize the genetic diversity of Mycobacterium tuberculosis in the population of this city, the genotyping techniques of spoligotyping and MIRU were applied to 93 isolates collected in two consecutive years from 93 different tuberculosis patients residing in São Paulo city and attending the Clemente Ferreira Institute (the reference clinic for the treatment of tuberculosis).Findings
Spoligotyping generated 53 different spoligotype patterns. Fifty-one isolates (54.8%) were grouped into 13 spoligotyping clusters. Seventy- two strains (77.4%) showed spoligotypes described in the international databases (SpolDB4, SITVIT), and 21 (22.6%) showed unidentified patterns. The most frequent spoligotype families were Latin American Mediterranean (LAM) (26 isolates), followed by the T family (24 isolates) and Haarlem (H) (11 isolates), which together accounted for 65.4% of all the isolates. These three families represent the major genotypes found in Africa, Central America, South America and Europe. Six Spoligo-International-types (designated SITs by the database) comprised 51.8% (37/72) of all the identified spoligotypes (SIT53, SIT50, SIT42, SIT60, SIT17 and SIT1). Other SITs found in this study indicated the great genetic diversity of M. tuberculosis, reflecting the remarkable ethnic diversity of São Paulo city inhabitants. The MIRU technique was more discriminatory and did not identify any genetic clusters with 100% similarity among the 93 isolates. The allelic analysis showed that MIRU loci 26, 40, 23 and 10 were the most discriminatory. When MIRU and spoligotyping techniques were combined, all isolates grouped in the 13 spoligotyping clusters were separated.Conclusions
Our data indicated the genomic stability of over 50% of spoligotypes identified in São Paulo and the great genetic diversity of M. tuberculosis isolates in the remaining SITs, reflecting the large ethnic mix of the São Paulo city inhabitants. The results also indicated that in this city, M. tuberculosis isolates acquired drug resistance independently of genotype and that resistance was more dependent on the selective pressure of treatment failure and the environmental circumstances of patients.124.
P Nauš P Perlíková A Bourderioux R Pohl L Slavětínská I Votruba G Bahador G Birkuš T Cihlář M Hocek 《Bioorganic & medicinal chemistry》2012,20(17):5202-5214
A series of novel sugar-modified derivatives of cytostatic 7-hetaryl-7-deazaadenosines (2'-C-methylribonucleosides, 2'-deoxy-2'-fluoroarabinonucleosides, arabinonucleosides and 2'-deoxyribonucleosides) was prepared and screened for biological activity. The synthesis consisted of preparation of the corresponding sugar-modified 7-iodo-7-deazaadenine nucleosides and their aqueous-phase Suzuki-Miyaura cross-coupling reactions with (het)arylboronic acids or Stille couplings with hetarylstannanes in DMF. The synthesis of 7-iodo-7-deazaadenine nucleosides was based on a glycosidation of 6-chloro-7-iodo-7-deazapurine with a suitable sugar synthon or on an interconversion of 2'-OH stereocenter (for arabinonucleosides). Several examples of 2'-C-Me-ribonucleosides showed moderate anti-HCV activities in a replicon assay accompanied by cytotoxicity. Several 7-hetaryl-7-deazaadenine fluoroarabino- and arabinonucleosides exerted moderate micromolar cytostatic effects. The most active was 7-ethynyl-7-deazaadenine fluoroarabinonucleoside which showed submicromolar antiproliferative activity. However, all the sugar-modified derivatives were less active than the parent ribonucleosides. 相似文献
125.
Grapevine bud fruitfulness is determined by the differentiation of uncommitted meristem (UCM) into either tendril or inflorescence.
Since tendril and inflorescence differentiation have long been considered sequential steps in inflorescence development, factors
that control the progression of floral meristem development may regulate the final outcome of UCM differentiation, and thus
affect fruitfulness. A comparison of the expression profiles of the master regulators of floral meristem identity (FMI) during
development of fruitful and non-fruitful buds along the same cane allowed associating the expression of a homolog of terminal flower 1 (TFL1, a negative regulator of FMI) to fruitful buds, and the expression of positive FMI regulators to non-fruitful buds. Combined
with (a) cytokinin-induced upregulation of VvTFL1A expression in cultured tendrils, which accompanied cytokinin-derived tendril
transformation into branched, inflorescence-like structures, (b) positive regulation of VvTFL1A expression by cytokinin, which
was demonstrated in transgenic embryonic culture expressing GUS reporter under the control of VvTFL1A promoter, and (c) a
significantly higher level of active cytokinins in fruitful positions, the data may support the assumption of cytokinin-regulated
VvTFL1A activity’s involvement in the control of inflorescence development. Such activity may delay acquisition of FMI and
allow an extended branching period for the UCM, resulting in the differentiation of inflorescence primordia. 相似文献
126.
Woojin S. Kim Lisa Perl Ji Hyeon Park Jade E. Tandianus Noel W. Dunn 《Current microbiology》2001,43(5):346-350
Different aspects of stress response of Lactobacillus acidophilus were investigated. First, the sublethal and lethal levels of bile, heat, and NaCl stresses were determined. They were 0.05%
and 0.5% (bile), 53°C and 60°C (heat), and 2% and 18% (NaCl), respectively. To evaluate the effect of each stress at log phase,
log-phase cultures were challenged directly with the lethal level of each stress (control) and were compared to log-phase
cultures that were pre-exposed to the sublethal level prior to the exposure at the lethal level (test). Some, if not most,
of the cells were killed in the control cultures against each of the three stresses. However, in the test cultures, the number
of cells that had survived increased significantly. It appears that L. acidophilus is capable of displaying adaptive response to stress. The adaptive response to one stress was also shown to provide cross-protection
against different stresses tested. The effect of each stress on stationary-phase cultures was also investigated. In contrast
to log-phase culture, stationary-phase culture was inherently resistant to stress.
Received: 5 March 2001 / Accepted: 3 April 2001 相似文献
127.
A. F. Perl 《CMAJ》1945,52(6):592-600
128.
A Horowitz Y Lanir F C Yin M Perl I Sheinman R K Strumpf 《Journal of biomechanical engineering》1988,110(3):200-207
A three-dimensional constitutive law is proposed for the myocardium. Its formulation is based on a structural approach in which the total strain energy of the tissue is the sum of the strain energies of its constituents: the muscle fibers, the collagen fibers and the fluid matrix which embeds them. The ensuing material law expresses the specific structural and mechanical properties of the tissue, namely, the spatial orientation of the comprising fibers, their waviness in the unstressed state and their stress-strain behavior when stretched. Having assumed specific functional forms for the distribution of the fibers spatial orientation and waviness, the results of biaxial mechanical tests serve for the estimation of the material constants appearing in the constitutive equations. A very good fit is obtained between the measured and the calculated stresses, indicating the suitability of the proposed model for describing the mechanical behavior of the passive myocardium. Moreover, the results provide general conclusions concerning the structural basis for the tissue overall mechanical properties, the main of which is that the collagen matrix, though comprising a relatively small fraction of the whole tissue volume, is the dominant component accounting for its stiffness. 相似文献
129.
130.