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901.
Comparative analyses of the complete genome sequences of Pierce's disease and citrus variegated chlorosis strains of Xylella fastidiosa 总被引:5,自引:0,他引:5
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Van Sluys MA de Oliveira MC Monteiro-Vitorello CB Miyaki CY Furlan LR Camargo LE da Silva AC Moon DH Takita MA Lemos EG Machado MA Ferro MI da Silva FR Goldman MH Goldman GH Lemos MV El-Dorry H Tsai SM Carrer H Carraro DM de Oliveira RC Nunes LR Siqueira WJ Coutinho LL Kimura ET Ferro ES Harakava R Kuramae EE Marino CL Giglioti E Abreu IL Alves LM do Amaral AM Baia GS Blanco SR Brito MS Cannavan FS Celestino AV da Cunha AF Fenille RC Ferro JA Formighieri EF Kishi LT Leoni SG Oliveira AR Rosa VE 《Journal of bacteriology》2003,185(3):1018-1026
Xylella fastidiosa is a xylem-dwelling, insect-transmitted, gamma-proteobacterium that causes diseases in many plants, including grapevine, citrus, periwinkle, almond, oleander, and coffee. X. fastidiosa has an unusually broad host range, has an extensive geographical distribution throughout the American continent, and induces diverse disease phenotypes. Previous molecular analyses indicated three distinct groups of X. fastidiosa isolates that were expected to be genetically divergent. Here we report the genome sequence of X. fastidiosa (Temecula strain), isolated from a naturally infected grapevine with Pierce's disease (PD) in a wine-grape-growing region of California. Comparative analyses with a previously sequenced X. fastidiosa strain responsible for citrus variegated chlorosis (CVC) revealed that 98% of the PD X. fastidiosa Temecula genes are shared with the CVC X. fastidiosa strain 9a5c genes. Furthermore, the average amino acid identity of the open reading frames in the strains is 95.7%. Genomic differences are limited to phage-associated chromosomal rearrangements and deletions that also account for the strain-specific genes present in each genome. Genomic islands, one in each genome, were identified, and their presence in other X. fastidiosa strains was analyzed. We conclude that these two organisms have identical metabolic functions and are likely to use a common set of genes in plant colonization and pathogenesis, permitting convergence of functional genomic strategies. 相似文献
902.
Felipe Gazos-Lopes Rafael Dias Mesquita Lívia Silva-Cardoso Raquel Senna Alan Barbosa Silveira Willy Jablonka Cecília Oliveira Cudischevitch Alan Brito Carneiro Ednildo Alcantara Machado Luize G. Lima Robson Queiroz Monteiro Roberto Henrique Nussenzveig Evelize Folly Alexandre Romeiro Jorick Vanbeselaere Lucia Mendon?a-Previato José Osvaldo Previato Jesus G. Valenzuela José Marcos Chaves Ribeiro Georgia Correa Atella Mário Alberto Cardoso Silva-Neto 《PloS one》2012,7(10)
Background
Rhodnius prolixus is a blood-sucking bug vector of Trypanosoma cruzi and T. rangeli. T. cruzi is transmitted by vector feces deposited close to the wound produced by insect mouthparts, whereas T. rangeli invades salivary glands and is inoculated into the host skin. Bug saliva contains a set of nitric oxide-binding proteins, called nitrophorins, which deliver NO to host vessels and ensure vasodilation and blood feeding. NO is generated by nitric oxide synthases (NOS) present in the epithelium of bug salivary glands. Thus, T. rangeli is in close contact with NO while in the salivary glands.Methodology/Principal Findings
Here we show by immunohistochemical, biochemical and molecular techniques that inositolphosphate-containing glycolipids from trypanosomatids downregulate NO synthesis in the salivary glands of R. prolixus. Injecting insects with T. rangeli-derived glycoinositolphospholipids (Tr GIPL) or T. cruzi-derived glycoinositolphospholipids (Tc GIPL) specifically decreased NO production. Salivary gland treatment with Tc GIPL blocks NO production without greatly affecting NOS mRNA levels. NOS protein is virtually absent from either Tr GIPL- or Tc GIPL-treated salivary glands. Evaluation of NO synthesis by using a fluorescent NO probe showed that T. rangeli-infected or Tc GIPL-treated glands do not show extensive labeling. The same effect is readily obtained by treatment of salivary glands with the classical protein tyrosine phosphatase (PTP) inhibitor, sodium orthovanadate (SO). This suggests that parasite GIPLs induce the inhibition of a salivary gland PTP. GIPLs specifically suppressed NO production and did not affect other anti-hemostatic properties of saliva, such as the anti-clotting and anti-platelet activities.Conclusions/Significance
Taken together, these data suggest that trypanosomatids have overcome NO generation using their surface GIPLs. Therefore, these molecules ensure parasite survival and may ultimately enhance parasite transmission. 相似文献903.
Leticia Ribeiro Oliveira Thais Kataoka Homma Renata Reis Woloszynek Vinícius Nahime Brito Carlos Alberto Longui 《Andrologie》2016,26(1):13
Background
The evaluation of prepubertal gonadal Leydig cells secretion requires gonadotropin stimulation. Urinary hCG (human chorionic gonadotropin) is currently unavailable in many countries, however, recombinant hCG (rhCG) can be used. Our aim was to evaluate rhCG-stimulated testicular hormones in a group of patients with cryptorchidism.Methods
We evaluated 31 prepubertal boys (age range, 0.75–9.0 years) presenting with unilateral (n?=?24) or bilateral (n?=?7) cryptorchidism. Patients with other genital abnormalities, previous use of hCG or testosterone or previous surgeries were excluded. Blood samples were obtained at baseline and 7 days after a single subcutaneous dose of rhCG (Ovidrel® 250 mcg) to measure the testosterone, DHT (dihydrotestosterone), AMH (anti-Mullerian hormone), and inhibin B levels.Results
rhCG stimulation significantly increased testosterone levels from 10 ng/dl to 247.8?±?135.8 ng/dl, increased DHT levels from 4.6?±?0.8 to 32.3?±?18.0 ng/dl, and increased the T/DHT ratio from 2.2?±?0.4 to 8.0?±?3.5. There was also a significant increase in inhibin B (from 105.8?±?65.2 to 132.4?±?56.1 pg/ml; p?<?0.05) and AMH levels (from 109.4?±?52.6 to 152.9?±?65.2 ng/ml; p?<?0.01) after the rhCG stimulation.Conclusions
In this cohort, hormonal responses can be elicited after the rhCG stimulation test, suggesting that rhCG is a promising stimulation test to replace the urinary hCG test during the evaluation of gonadal Leydig cells function. The clinical applicability and adequate performance of rhCG testing must be investigated in future studies.904.
Martina Proietti Onori Linda M. C. Koene Carmen B. Schfer Mark Nellist Marcel de Brito van Velze Zhenyu Gao Ype Elgersma Geeske M. van Woerden 《PLoS biology》2021,19(5)
Hyperactivation of the mammalian target of rapamycin (mTOR) pathway can cause malformation of cortical development (MCD) with associated epilepsy and intellectual disability (ID) through a yet unknown mechanism. Here, we made use of the recently identified dominant-active mutation in Ras Homolog Enriched in Brain 1 (RHEB), RHEBp.P37L, to gain insight in the mechanism underlying the epilepsy caused by hyperactivation of the mTOR pathway. Focal expression of RHEBp.P37L in mouse somatosensory cortex (SScx) results in an MCD-like phenotype, with increased mTOR signaling, ectopic localization of neurons, and reliable generalized seizures. We show that in this model, the mTOR-dependent seizures are caused by enhanced axonal connectivity, causing hyperexcitability of distally connected neurons. Indeed, blocking axonal vesicle release from the RHEBp.P37L neurons alone completely stopped the seizures and normalized the hyperexcitability of the distally connected neurons. These results provide new evidence of the extent of anatomical and physiological abnormalities caused by mTOR hyperactivity, beyond local malformations, which can lead to generalized epilepsy.Hyperactivation of the mTOR pathway can cause cortical malformations and epilepsy. This study reveals that these effects can be uncoupled and that mTOR hyperactivity in a limited set of neurons induces hyperexcitability in non-targeted, healthy neurons, suggesting that it is actually these changes that may underlie mTOR-driven epileptogenesis. 相似文献
905.
906.
Alejandro O Luquetti Suelene Brito do Nascimento Tavares Liliane da Rocha Siriano Rozangela Amaral de Oliveira Dayse Elizabeth Campos Cicilio Alves de Morais Enio Chaves de Oliveira 《Memórias do Instituto Oswaldo Cruz》2015,110(3):369-376
Transmission of Trypanosoma cruzi during pregnancy is estimated to
occur in less than 20% of infected mothers; however, the etiopathogenesis is not
completely understood. The Centre for Studies on Chagas Disease provides confirmation
of T. cruzi infection for individuals living in central Brazil.
In this retrospective hospital-based study, all requests for diagnosis of T.
cruzi infection in individuals less than 21 years old from 1994-2014 were
searched. We end with 1,211 individuals and their respective infected mothers.
Congenital transmission of infection was confirmed in 24 individuals (2%) in central
Brazil, an area where the main T. cruzi lineage circulating in
humans is TcII. This low prevalence of congenital Chagas disease is discussed in
relation to recent findings in the south region of Brazil, where TcV is the main
lineage and congenital transmission has a higher prevalence (approximately 5%),
similar to frequencies reported in Argentina, Paraguay and Bolivia. This is the first
report to show geographical differences in the rates of congenital transmission
of T. cruzi and the relationship between the prevalence of
congenital transmission and the type of Tc prevalent in each region. 相似文献
907.
908.
The occurrence of the fish Cephalopholis taeniops (Serranidae: Epinephelinae) has been recorded for the first time in the Canary Islands (eastern subtropical Atlantic). Repeated observations of adult stages of the species (??30?cm total length) inside oil platforms coming from the Gulf of Guinea greatly suggest an introduction related to the transport of ballast water in these structures, and show their importance in the dispersal of adult stages of large-sized species of littoral fish. Oil platforms constitute one special case in the introduction of marine species in the context of ballast water transport. This poorly known phenomenon may greatly favour marine species invasion, and might have significant repercussions in many regions -especially in the current climate change context- as well as explaining some surprising cases of occurrence of expatriated adult individuals of certain species. 相似文献
909.
Alexsander Augusto da Silveira Jackeline Santana Paula Andrade Ana Carla Peixoto Guissoni Adeliane Castro da Costa Arthur de Carvalho e Silva Heloisa Garcia da Silva Pedro Brito Guilherme Rocha Lino de Souza Kátia Flávia Fernandes 《Biotechnology progress》2021,37(5):e3182
Aedes aegypti is a mosquito vector of arboviruses such as dengue, chikungunya, zika and yellow fever that cause important public health diseases. The incidence and gravity of these diseases justifies the search for effective measures to reduce the presence of this vector in the environment. Bioinsecticides are an effective alternative method for insect control, with added ecological benefits such as biodegradability. The current study demonstrates that a chitinolytic enzyme complex produced by the fungus Trichoderma asperellum can disrupt cuticle formation in the L3 larvae phase of A. aegypti, suggesting such biolarvicidal action could be used for mosquito control. T. asperellum was exposed to chitin from different sources. This induction of cell wall degrading enzymes, including chitinase, N-acetylglucosaminidase and β-1,3-glucanase. Groups of 20 L3 larvae of A. aegypti were exposed to varying concentrations of chitinolytic enzymes induced with commercial chitin (CWDE) and larvae cell wall degrading enzymes (L-CWDE). After 72 h of exposure to the CWDE, 100% of larvae were killed. The same percent mortality was observed after 48 h of exposure to L-CWDE at half the CWDE enzyme mixture concentration. Exoskeleton deterioration was further observed by scanning and electron microscopy. Our findings indicate that L-CWDE produced by T. asperellum reflect chitinolytic enzymes with greater specificity for L3 larval biomolecules. This specificity is characterized by the high percentage of mortality compared with CWDE treatments and also by abrupt changes in patterns of the cellular structures visualized by scanning and transmission electron microscopy. These mixtures of chitinolytic enzymes could be candidates, as adjuvant or synergistic molecules, to replace conventional chemical insecticides currently in use. 相似文献
910.
Seminal coagulation and sperm quality in different social contexts in captive tufted capuchin monkeys (Sapajus apella)
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