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921.
Cerda-Molina AL Hernández-López L Páez-Ponce DL Rojas-Maya S Mondragón-Ceballos R 《Theriogenology》2006,66(8):1985-1993
A number of studies in free-ranging and captive spider monkeys (Ateles spp.) have shown that this genus is able to reproduce throughout the entire year. Nonetheless, it is still controversial whether births, and therefore conceptions, tend to be more frequent during certain seasons. In the present study, we monitored changes in fecal 17beta-estradiol and progesterone for approximately 1 years in five female black-handed spider monkeys (Ateles geoffroyi) kept in captivity in Mexico City. The objective was to determine whether hormone concentrations and menstrual cycles of summer and autumn accounted for a greater chance of conception than those of winter and spring, consistent with birth patterns previously reported. We collected fecal samples from the five monkeys almost daily for 1 year (March 2004 to February 2005) and used radioimmunoassay of fecal extracts to determine concentrations of 17beta-estradiol and progesterone. Concurrently, menstrual cycle phases were determined by cytological evaluation of vaginal swabs. Periovulatory 17beta-estradiol concentrations were significantly higher in autumn than in winter, spring or summer. Moreover, as evidenced by progesterone peaks, most of the summer-autumn menstrual cycles were ovulatory; in contrast, most of the winter and spring cycles were anovulatory. In conclusion, our data supported the notion that, although not a strictly seasonal reproducer, the black-handed spider monkey is more likely to conceive at the end of the rainy season and throughout autumn. 相似文献
922.
Ricardo Bisquert Andrés Planells-Cárcel Elena Valera-García José Manuel Guillamón Sara Muñiz-Calvo 《Microbial biotechnology》2022,15(5):1499-1510
Hydroxytyrosol (HT) is one of the most powerful dietary antioxidants with numerous applications in different areas, including cosmetics, nutraceuticals and food. In the present work, heterologous hydroxylase complex HpaBC from Escherichia coli was integrated into the Saccharomyces cerevisiae genome in multiple copies. HT productivity was increased by redirecting the metabolic flux towards tyrosol synthesis to avoid exogenous tyrosol or tyrosine supplementation. After evaluating the potential of our selected strain as an HT producer from glucose, we adjusted the medium composition for HT production. The combination of the selected modifications in our engineered strain, combined with culture conditions optimization, resulted in a titre of approximately 375 mg l−1 of HT obtained from shake-flask fermentation using a minimal synthetic-defined medium with 160 g l−1 glucose as the sole carbon source. To the best of our knowledge, this is the highest HT concentration produced by an engineered S. cerevisiae strain. 相似文献
923.
Laguna de Cuyutlán, in the state of Colima, Mexico, is the only large coastal wetland in a span of roughly 1150 km. Despite this, the study of its birds has been largely neglected. Between 2003 and 2006 we assessed the waterbirds nesting in the middle portion of Laguna Cuyutlán, a large tropical coastal lagoon, through field visits. We documented the nesting of 15 species of non-Laridae waterbirds: Neotropic Cormorant (Phalacrocorax brasilianus), Tricolored Egret (Egretta tricolor), Snowy Egret (Egretta thula), Little Blue Heron (Egretta caerulea), Great Egret (Ardea alba), Cattle Egret (Bubulcus ibis), Black-crowned Night-heron (Nycticorax nycticorax), Yellow-crowned Night-heron (Nyctanassa violacea), Green Heron (Butorides virescens), Roseate Spoonbill (Platalea ajaja), White Ibis (Eudocimus albus), Black-bellied Whistling-duck (Dendrocygna autumnalis), Clapper Rail (Rallus longirostris), Snowy Plover (Charadrius alexandrinus), and Black-necked Stilt (Himantopus mexicanus). These add to six species of Laridae known to nest in that area: Laughing Gulls (Larus atricilla), Royal Terns (Thalasseus maximus), Gull-billed Terns (Gelochelidon nilotica), Forster's Terns (S. forsteri), Least Terns (Sternula antillarum), and Black Skimmer (Rynchops niger), and to at least 57 species using it during the non-breeding season. With such bird assemblages, Laguna Cuyutlán is an important site for waterbirds, which should be given conservation status. 相似文献
924.
Valery A. Isidorov Paweł Lech Anna Żółciak Magdalena Rusak Lech Szczepaniak 《Trees - Structure and Function》2008,22(4):531-542
An investigation was carried out of the composition of metabolites in pine seedlings tissues at the initial stages of the
infectious process caused by pathogenic fungi Armillaria ostoyae, which causes a root rot of trees and degradation of forest resources. With the help of successive extraction with organic
solvents of different polarity, more than 190 metabolites were extracted from the needles and roots of the seedlings and then
identified by GC–MS method. The composition of the extracts from control plants and those inoculated with Armillaria ostoyae were compared. It was established that part of secondary metabolites (glucosamines and free amino acids, carbohydrates raffinose
and trehalose) were present only in the tissues of inoculated plants. Possible roles of some of these compounds appearing
in the roots of seedlings infected with the fungus are also discussed in the paper. 相似文献
925.
Doleviczényi Z Vizi ES Gacsályi I Pallagi K Volk B Hársing LG Halmos G Lendvai B Zelles T 《Neurochemical research》2008,33(11):2364-2372
In humans, serotonin (5-HT) has been implicated in numerous physiological and pathological processes in the peripheral auditory
system. Dopamine (DA), another transmitter of the lateral olivocochlear (LOC) efferents making synapses on cochlear nerve
dendrites, controls auditory nerve activation and protects the sensory nerve against overactivation. Using in vitro microvolume
superfusion techniques we tested 5-HT6 and 5-HT7 receptor antagonists whether they can influence dopamine (DA) release from the guinea-pig cochlea in control and in ischemic
conditions using currently available and new 5-HT6 and 5-HT7 antagonists and mixed antagonists, which were synthesized and characterized for the current study. While the 5-HT7 antagonist SB-258719 was ineffective, SB-271046, which blocks the 5-HT6 receptor, caused a significant increase in cochlear DA release what is contradictory with the excitatory nature of this type
of receptor. Moreover, the mixed 5-HT6/7 antagonist EGIS-12233 induced an even more pronounced increase in the resting DA release. To understand why the block of
an excitatory receptor results in an increase instead of a decrease in function, we investigated the possible involvement
of an indirect neural mechanism through an inhibitory system. In the presence of the GABAA receptor blocker bicuculline, EGIS-12233 failed to increase the release of DA, suggesting that the serotonin receptor modulation
of DA release from the lateral olivocochlear efferents in the cochlea was produced indirectly by decreasing the GABAergic
inhibitory tone on dopaminergic nerve endings. The mixed 5-HT7/D4 receptor antagonist EGIS-11983 significantly increased both the stimulation-evoked and the resting DA release, while the
selective D4 blocker L-741,741 alone had no significant effect. Ischemia, simulated by oxygen and glucose deprivation from
the perfusion solution had no action on the effect of the drugs. Drugs that can increase the release of DA from LOC terminals
in the cochlea may have a role in the treatment of sensorineural hearing loss. 相似文献
926.
Cinco-Moroyoqui FJ Díaz-Malváez FI Alanís-Villa A Barrón-Hoyos JM Cárdenas-López JL Cortez-Rocha MO Wong-Corral FJ 《Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology》2008,150(2):153-160
Three isoamylases of Rhyzopertha dominica (termed RdA70, RdA79, and RdA90 according to their relative mobility in gel electrophoresis) were isolated by ammonium sulfate fractionation and hydrophobic interaction chromatography. RdA70 and RdA79 showed an optimal pH of 7.0, whereas for RdA90 the optimal pH was 6.5. The three isoamylases remained stable at 50 °C for 1 h, but at 60 °C, all lost 50% of their activity in 20 min and were completely inactivated in 1 h. RdA70 and RdA79 were inhibited by albumin extracts from wheat samples varying widely in amylase inhibitory activity; however, RdA90 was highly resistant to inhibition. β-Mercaptoethanol up to 30 mM increased the activity of the three isoamylases by 2.5-fold. The action pattern of the three isoamylases was typical of endoamylases; however, differences were observed on the hydrolytic efficiency rates measured as Vmax/Km ratio on starch, amylopectin, and amylose. The hydrolyzing action of RdA90 on starch and amylopectin (Vmax/Km = 90.4 ± 2.3 and 78.9 ± 6.6, respectively) was less efficient than that on amylose (Vmax/Km = 214 ± 23.2). RdA79 efficiently hydrolyzed both amylopectin and amylose (Vmax/Km = 260.6 ± 12.9 and 326.5 ± 9.4, respectively). RdA70 hydrolyzed starch and amylose at similar rates (Vmax/Km = 202.9 ± 5.5 and 215.9 ± 6.2, respectively), but amylopectin was a poor substrate (Vmax/Km = 124.2 ± 7.4). The overall results suggest that RdA70 and RdA79 appear to belong to a group of saccharifying isoamylases that breaks down long fragments of oligosaccharide chains produced by the hydrolytic action of RdA90. The simultaneous action of the three isoamylases on starch, aside from the high resistance of RdA90 to wheat amylase inhibitors, might allow R. dominica to feed and reproduce successfully on the wheat kernel. 相似文献
927.
Six sandy beaches on the North West coast of Spain, exposed to different wave action, were sampled in order to study the macroinfauna
community and the biopolymeric fraction (proteins, lipids and carbohydrates) of sedimentary organic matter. According to McLachlan’s
rating system (1980), three of them were classified as sheltered and the other three as exposed beaches. Sampling was carried
out during August 2004 at three tidal levels: high, medium and low. Macroinfauna community and organic matter concentrations
were found to be significantly different when sheltered and exposed beaches were compared. Macroinfauna diversity (H′), abundances
and biomass became increasingly enriched along a gradient from exposed to sheltered beaches. Macroinfauna mean abundance was
found higher in sheltered (ranked from 1535 ± 358 to 15062 ± 5771 ind m−2) than in exposed beaches (from 150 ± 41 to 5518 ± 1986 ind m−2). Macroinfauna biomass ranged from 3.2 to 14.7 g m−2 and species richness from 25 to 27 in sheltered localities; while in exposed beaches, biomass ranged from 0.2 to 2.3 g m−2 and the number of species from 5 to 14. The biopolymeric carbon concentration (BPC) was significantly higher in sheltered
(from 84.7 ± 44.7 to 163.3 ± 34.8) than in exposed (from 30.3 ± 7.5 to 78.7 ± 12.3) beaches. The low hydrodynamic conditions
of sheltered beaches favoured the settlement of organic rich fine sediments, being supported by the higher protein to carbohydrate
ratio found in the exposed (from 23.5 ± 0.9 to 32.7 ± 4.4), rather than in the sheltered localities (from 6.2 ± 0.7 to 13.6).
Mean macroinfauna abundances were higher at medium and low tidal levels in both sheltered and exposed beaches. Crustacea was
found to be the main group inhabiting the upper part of both types of beaches, dominating all tidal levels of exposed sandy
beaches. Mollusca and Polychaeta groups were dominant in sheltered beaches at the medium and lower levels. There was a significant
negative relationship between the BPC and the beach face slope; thus, BPC decreased as the intertidal slope increased. It
seems that exposed sandy beaches are mainly physically controlled, whereas hospitable sheltered beaches let other factors,
such as biochemical compounds, enrich the benthic fauna scenery.
Electronic Supplementary Material Supplementary material is available in the online version of this article at and is accessible for authorized users
Handling editors: K. Martens 相似文献
928.
Rezessy-Szabó JM Nguyen QD Hoschke A Braet C Hajós G Claeyssens M 《Biochimica et biophysica acta》2007,1770(1):55-62
High levels of an extracellular alpha-galactosidase are produced by the thermophilic fungus Thermomyces lanuginosus CBS 395.62/b when grown in submerse culture and induced by sucrose. The enzyme was purified 114-fold from the culture supernatant by (NH(4))(2)SO(4) fractionation, and by chromatographical steps including Sepharose CL-6B gel filtration, DEAE-Sepharose FF anion-exchange, Q-Sepharose FF anion-exchange and Superose 12 gel filtration. The purified enzyme exhibits apparent homogeneity as judged by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and iso-electric focusing (IEF). The native molecular weight of the monomeric alpha-galactosidase is 93 kDa with an isoelectric point of 3.9. The enzyme displays a pH and temperature optimum of 5-5.5 and 65 degrees C, respectively. The purified enzyme retains more than 90% of its activity at 45 degrees C in a pH range from 5.5 to 9.0. The enzyme proves to be a glycoprotein and its carbohydrate content is 5.3%. Kinetic parameters were determined for the substrates p-nitrophenyl-alpha-galactopyranoside, raffinose and stachyose and very similar K(m) values of 1.13 mM, 1.61 mM and 1.17 mM were found. Mn(++) ions activates enzyme activity, whereas inhibitory effects can be observed with Ca(++), Zn(++) and Hg(++). Five min incubation at 65 degrees with 10 mM Ag(+) results in complete inactivation of the purified alpha-galactosidase. Amino acid sequence alignment of N-terminal sequence data allows the alpha-galactosidase from Thermomyces lanuginosus to be classified in glycosyl hydrolase family 36. 相似文献
929.
Sousa AF Andrade PZ Pirzgalska RM Galhoz TM Azevedo AM da Silva CL Aires-Barros MR Cabral JM 《Biotechnology letters》2011,33(12):2373-2377
A novel cell separation process based on immunoaffinity aqueous two phase systems is presented to isolate and purify CD34+ stem/progenitor cells directly from the whole umbilical cord blood (UCB). A system, composed of polyethylene glycol and dextran,
was evaluated for the selective recovery of CD34+ cells from UCB. A monoclonal antibody against the CD34 surface antigen was used for the direct partitioning of CD34+ cells in UCB to the PEG-rich phase. The initial population of CD34+ cells (0.2% of the initial sample) was enriched to values up to 42% in a single partitioning step, while the majority of
contaminant cells were partitioned to the dextran-rich phase (1.37 × 10−2 < KP < 2.76 × 10−2). This novel selection method allowed a recovery yield of 95% of CD34+ cells with a purification factor of 245 and is expected to pave a new way to purify hematopoietic stem/progenitor cells for
use in a variety of clinical settings. 相似文献
930.
Harpacticoida (Crustacea: Copepoda) of the South China Sea: faunistic and biogeographical analysis 总被引:1,自引:0,他引:1
Based on original and on published databases, a compendium of the Harpacticoida of the South China Sea is presented, and the distributional range of species is discussed. Up to now, a total of 77 harpacticoid species belonging to 57 genera and 19 families have been recorded in this region. Twenty of these species, collected in Nha-Trang Bay (Vietnam), have not hitherto been described. The most speciose families are the Miraciidae (20 species) and the Laophontidae (9 species). Thirteen families were represented by one to three species only and six families by four to seven species. A brief comparison is presented between the harpacticoid fauna of the South China Sea, the Philippine Islands, the inner Malayan Archipelago (Java, Flores, Banda, and Celebes Seas), New Guinea, the Yellow Sea, and the Andaman and Nicobar Islands. The overall similarity between the species lists of these areas was observed to be extremely low (average value of Simpson index is 0.15 ± 0.08). The lists of planktonic species from the different areas showed the highest similarity. The lowest similarity (highest endemism) was observed between the lists of interstitial species. It is likely that one of the factors determining the differences between the faunas is the poor knowledge about the composition and distribution of benthic harpacticoids in tropical latitudes. 相似文献