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431.
F Clavel F Brun-Vézinet D Guétard S Chamaret A Laurent C Rouzioux M Rey C Katlama F Rey J L Champelinaud 《Comptes rendus de l'Académie des sciences. Série III, Sciences de la vie》1986,302(13):485-488
A second retrovirus, named LAV-II, has been isolated from two West-African patients with AIDS. By its genomic sequences and its proteins, this virus is different from the LAV-I/HTLV-III, isolated from U.S.A., Europe and Central Africa. It differs also from STLV-III, isolated from Rhesus Macaques with AIDS, but displays an antigenic relationship with the latter virus, at the level of its external envelope protein. The tropism of LAV-II for T4 lymphocytes and the induction of cytopathic effect in infected cells are similar to those of LAV-I. 相似文献
432.
Radovan Borojevic Alvaro N. A. Monteiro Solange A. Vinhas Gilberto B. Domont Paulo A. S. Mourão Hervé Emonard Gabriel Grimaldi Jr. Jean-Alexis Grimaud 《In vitro cellular & developmental biology. Plant》1985,21(7):382-390
Summary A continuous murine cell line (GRX) was obtained from fibrotic granulomas induced in C3H/HeN mice liver by experimental infection
withSchistosoma mansoni. This anchorage-dependent line produces composite connective tissue/extracellular matrix, displays morphological characteristics
of myofibroblasts, and can, under appropriate conditions, accumulate fat droplets. GRX cells produce viral particles of retrovirus
type. We consider GRX cell line to be representative of liver connective tissue cells, responsible for fibroplasia in liver
fibrotic and granulomatous reactions.
This research was supported by Centre National de la Recherche Scientifique, France; Financiadora de Estudos e Projetos (FINEP),
Brasil; and Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brasil. 相似文献
433.
In this paper, we present an original model of the atria, based on our hypothesis that atrial cells have features of pacemaker
cells, characterized by their normally longer intrinsic cycle lengths and different type of connection (stronger) than the,
sino-atrial (SA) node pacemaker cells. The atrium is simulated by a two-dimensional array of pacemaker cells (25 × 25), composed
of a region of SA node pacemaker cells (11 × 11) surrounded by atrial pacemaker cells. All pacemakers cells are characterized
by only the most relevant functional properties, those which play the most direct role in the determination of the cardiac
rate and in the mechanism of arrhythmias. These properties are: the intrinsic cycle length, τ, an `internal' feature of each
pacemaker cell, and the phase-response curve (PRC), an `overall collective' function. The PRC embodies the interactions of
each pacemaker cell with its neighboring cells, and thus represents the type of connection (strong, weak, etc.) of the pacemaker
cell with its surroundings. In our model, the SA node region differs from the atrial region by cycle length distribution and
PRCs. We studied the spatial interaction between SA node pacemaker cells and atrial pacemaker cells as a function of the regional
variation of cells properties and as a function of the “electrical” coupling between cells (the PRC), in the SA node region,
in the atrial region, and in a border zone between them. We investigated the influence of those parameters on the activation
pattern, on the conduction time of the array, and on a pseudo-ECG signal. This study demonstrates that by representing the
atrial cells as a population of `pacemaker-like' cells, similar to the SA node pacemaker cells, but differing markedly in
their cycle lengths and cell-to-cell interaction (PRC), we can create a global picture of the atrial system by applying a
simple physical-mathematical model. This approach enables us to explore physiological phenomena related to the genesis and
maintenance of atrial activity. It also reveals the conditions which predispose to atrial arrhythmias and conduction disturbances
(e.g. tachycardia, pacemaker shift, re-entry, fibrillation). In particular, it yields insight into the mechanism of transition
from normal atrial activity to the disordered state of atrial fibrillation. Therefore, this study suggests a new way of looking
at the development of cardiac arrhythmias of atrial origin.
Received: 8 September 1997 / Accepted in revised form: 6 October 1998 相似文献
434.
Gladys Len De Pinto Maritza Martínez Solange Ortega Neida Villavicencio Lisbeth Borjas 《Biochemical Systematics and Ecology》1993,21(8):795-797
Analytical data are presented for the polysaccharide of six gum specimens from Acacia tortuosa, a tropical American Gummiferae species. These data show that the gums were basically similar but differed in the sugar composition reported for most Acacia gum exudates studied so far. The presence of traces of xylose (<1%) and the absence of rhamnose in the gum specimens studied was very unusual. 相似文献
435.
Osvaldo A. Sant'Anna Solange Massa Denise Mouton Yolande Bouthillier Jean-Claude Mevel Olga M. Ibanez Ruth Vassao Marcelo de Franco Raquel Bellinati Maria Siqueira Guido Biozzi 《FEMS microbiology letters》1989,47(8-9):465-472
Abstract Susceptibility to Salmonella typhimurium infection was compared in H (high Ab responder) and L (low Ab responder) mice obtained by several selective breeding experiments (Selections I, II, III, IV and IV A) [10,19,22]. H mice were always much more susceptible to infection than their L mice counterparts within a continuous LD 50 variation range. In three of the selections (I, II and IV A) the low responsiveness character is known to result mainly from rapid Ag degradation in L mice macrophages. It was hypothesized that resistance to multiplication of intracellular pathogens could be related to an increased catabolic activity towards Ag. This was actually demonstrated, in F2 segregant hybrids of selection IV A, by the significant inverse correlation between capacity for Ab production and resistance to infection. 相似文献
436.
Denise Bohrer Paulo Cícero do Nascimento Regina Binotto Solange Cristina Pomblum 《Journal of trace elements in medicine and biology》2001,15(2-3)
The presence of aluminium (Al) in pharmaceutical products used parenterally as sodium and potassium chlorides, glucose, heparin and albumin were investigated with respect to their storage in glass containers. As glasses can have aluminium in their composition, the aluminium may be released from the glass into the solution. The action of the substances above mentioned were investigated storing their solutions in glass and plastic containers, and measuring the aluminium in solution at determined time intervals. The aluminium present in the commercial pharmaceutical products, stored in both plastic and glass containers were also measured. All glass containers were analysed to determine their aluminium content. The aluminium determinations were done by atomic absorption spectrometry. The results showed that aluminium is present in all analysed glasses in a percentage of 0.6 to 3%. Although all substances already have a residual aluminium contamination, the major contribution comes from the glass containers in which their solutions were stored. The contamination arising from glass depends too much on the nature of the substance. While the salts extracted about 400 μg Al/l in 60 days, glucose extracted 150 μg Al/l, and albumin and heparin about 500 μg Al/l in the same time interval. Commercial solutions of glucose contain about 10 μg Al/l when stored in polyethylene and from 350 to 1000 μg Al/l when in glass ampules. Considering all commercial products, solutions stored in plastic containers contained no more than 20 μg Al/l whereas in glass the aluminium contamination reached 1000 μg/l, and in all of them the aluminium increases with the age of the product. 相似文献
437.
da Silva Júnior EN de Souza MC Fernandes MC Menna-Barreto RF Pinto Mdo C de Assis Lopes F de Simone CA Andrade CK Pinto AV Ferreira VF de Castro SL 《Bioorganic & medicinal chemistry》2008,16(9):5030-5038
New naphthoquinone derivatives were synthesized and assayed against bloodstream trypomastigote forms of Trypanosoma cruzi, the etiological agent of Chagas’ disease. The compounds were rationalized based on hybrid drugs and appear as important compounds against this parasite. From nor-lapachol were prepared five substituted ortho-naphthofuranquinones, a non-substituted para-naphthofuranquinone, a new oxyrane and an azide and from -lapachone a new non-substituted para-naphthofuranquinone. Other five substituted ortho-naphthofuranquinones recently designed as cytotoxic, were also evaluated. The most active compounds were the ortho naphthofuranquinones 3-(4-methoxyphenylamino)-2,3-dihydro-2,2-dimethylnaphtho[1,2-b]furan-4,5-dione and 3-(3-nitrophenylamino)-2,3-dihydro-2,2-dimethylnaphtho[1,2-b]furan-4,5-dione with trypanocidal activity higher than that of benznidazole, the standard drug. The compounds were rationalized based on hybrid drugs and appear as important compounds against T. cruzi. The trypanocidal activity of these substances endowed with redox properties representing a good starting point for a medicinal chemistry program aiming the chemotherapy of Chagas’ disease. 相似文献
438.
Bohrer D Dessuy MB Kaizer R do Nascimento PC Schetinger MR Morsch VM de Carvalho LM Garcia SC 《Analytical biochemistry》2008,377(2):120-127
Four different procedures for the determination of aluminum in tissues by atomic absorption spectrometry (AAS) were investigated. They consisted of conventional acid digestion carried out before and after sample drying, associated or not with fat extraction. Drying was carried out in a conventional oven at 65 °C for 24 h. For fat extraction, different solvents and solvent mixtures were investigated considering both extraction yield and sample adequacy for further AAS measurement. Acid digestion was carried out with pure HNO3 or with its mixture with HClO4. After digestion, aluminum was measured by graphite furnace atomic absorption spectrometry. Tissues were collected from Al-exposed and nonexposed mice. The results indicated that drying the sample prior to digestion is advantageous as the amount of acid necessary can be significantly reduced. This procedure does not contribute to increase the aluminum level in the samples providing that careful measures to avoid contamination are taken, as the same procedures carried out without taking any precautions to avoid contamination produced imprecise results. Finally, aluminum was not found in the fatty fraction of any sample, even in exposed mice, demonstrating that aluminum does not accumulate in this part of the tissues. 相似文献
439.
Greice Lubini Juliana M. Fachinetto Haywood D. LaughinghouseIV Juçara T. Paranhos Antonio C. F. Silva Solange B. Tedesco 《Biologia》2008,63(5):647-651
Some species of Psychotria (Rubiaceae) are important in herbal medicine, where their extracts are used internally for infections of the female reproductive
system, bronchitis, gastrointestinal disturbances, skin irritations, tumors, ulcers, and eye disturbances. The antiproliferative
and genotoxic effects of Psychotria myriantha Mull. Arg. and P. leiocarpa Cham. et Schlecht infusions on the Allium cepa L. cell cycle were evaluated. The teas were prepared by infusing the leaves in distilled water, in two concentrations: 1.13
mg/mL and 6.78 mg/mL. Three groups of four bulbs were used for each Psychotria species. After the bulbs rooted in distilled water, they were transferred to the teas for 24 hours, except for the control
that stayed in water. The rootlets were then collected, fixed in ethanol-acetic acid (3:1) for 24 hours, and stored in 70%
ethanol. For each group of bulbs, 4000 cells were analyzed, calculating the mitotic indexes, submitting them to statistic
analysis, using the χ
2 test (p = 0.05). The results showed a decrease in mitotic index with an increase in tea concentration in both species. In P. leiocarpa, the mitotic index values differed significantly between the control and concentration of 6.78 mg/mL (χ
2 = 9.863). For P. myriantha, the values referring to the mitotic index differed greatly between the control and the treatments (χ
2 = 124.8). With this study, it was determined that P. myriantha and P. leiocarpa infusions possess antiproliferative effects on the A. cepa cell cycle, and teas of P. myriantha also have genotoxic activity. 相似文献
440.
The ALDH21 gene found in lower plants and some vascular plants codes for a NADP+‐dependent succinic semialdehyde dehydrogenase
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Martina Kopečná Armelle Vigouroux Jan Vilím Radka Končitíková Pierre Briozzo Eva Hájková Lenka Jašková Klaus von Schwartzenberg Marek Šebela Solange Moréra David Kopečný 《The Plant journal : for cell and molecular biology》2017,92(2):229-243
Lower plant species including some green algae, non‐vascular plants (bryophytes) as well as the oldest vascular plants (lycopods) and ferns (monilophytes) possess a unique aldehyde dehydrogenase (ALDH) gene named ALDH21, which is upregulated during dehydration. However, the gene is absent in flowering plants. Here, we show that ALDH21 from the moss Physcomitrella patens codes for a tetrameric NADP+‐dependent succinic semialdehyde dehydrogenase (SSALDH), which converts succinic semialdehyde, an intermediate of the γ‐aminobutyric acid (GABA) shunt pathway, into succinate in the cytosol. NAD+ is a very poor coenzyme for ALDH21 unlike for mitochondrial SSALDHs (ALDH5), which are the closest related ALDH members. Structural comparison between the apoform and the coenzyme complex reveal that NADP+ binding induces a conformational change of the loop carrying Arg‐228, which seals the NADP+ in the coenzyme cavity via its 2′‐phosphate and α‐phosphate groups. The crystal structure with the bound product succinate shows that its carboxylate group establishes salt bridges with both Arg‐121 and Arg‐457, and a hydrogen bond with Tyr‐296. While both arginine residues are pre‐formed for substrate/product binding, Tyr‐296 moves by more than 1 Å. Both R121A and R457A variants are almost inactive, demonstrating a key role of each arginine in catalysis. Our study implies that bryophytes but presumably also some green algae, lycopods and ferns, which carry both ALDH21 and ALDH5 genes, can oxidize SSAL to succinate in both cytosol and mitochondria, indicating a more diverse GABA shunt pathway compared with higher plants carrying only the mitochondrial ALDH5. 相似文献