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111.
112.
This paper describes a rapid and sensitive method to determine inorganic phosphate, even in the presence of labile organic phosphate compounds and large quantities of proteins. The method eliminates the use of sodium arsenite, a highly toxic compound, substituting bismuth citrate for it to stabilize the phosphomolybdic acid complex formed during the interaction of inorganic phosphate and molybdate reduced by ascorbic acid. This method has also been adapted to microplates and has been used to determine the activities of Na/K ATPase and alkaline phosphatase of intestinal basolateral and luminal plasma membranes. 相似文献
113.
de Oca Porto RM Fernández AR Brito DM Vidal TC Diaz AL 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2006,830(1):178-183
Danazol (17alpha-pregna-2,4-dien-20-yno [2,3-d]-isoxazol-17beta-ol), is a synthetic derivative of ethisterone, structurally related to stanozolol. For this reason its use as doping agent has been investigated. Danazol (Runch) (200 mg) were orally administered to two healthy male volunteers. Urine samples were collected up to 1-week post-dose. Four new metabolites have been identified in addition to the five previously reported. We propose the monitorization of 6beta-hydroxy-2-hydroxymethyl-1,2-dehydroethisterone and 6beta,16epsilon-dihydroxy-2epsilon-hydroxymethyl-ethisterone by free fraction analysis. In a same way, we proposed to detect the principal isomer of a mono-hydroxylated metabolite of 6beta-hydroxy-2epsilon-hydroxymethylethisterone in the conjugated fraction. We conclude that new metabolites can be included for the detection of danazol abuse since the main metabolite ethisterone is excreted relatively fast in urine. 相似文献
114.
115.
Tattersall GJ de Andrade DV Brito SP Abe AS Milsom WK 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2006,176(2):125-138
In order to study the relative roles of receptors in the upper airways, lungs and systemic circulation in modulating the ventilatory
response of caiman (Caiman latirostris) to inhaled CO2, gas mixtures of varying concentrations of CO2 were administered to animals breathing through an intact respiratory system, via a tracheal cannula by-passing the upper
airways (before and after vagotomy), or via a cannula delivering gas to the upper airways alone. While increasing levels of
hypercarbia led to a progressive increase in tidal volume in animals with intact respiratory systems (Series I), breathing
frequency did not change until the CO2 level reached 7%, at which time it decreased. Despite this, at the higher levels of hypercarbia, the net effect was a large
and progressive increase in total ventilation. There were no associated changes in heart rate or arterial blood pressure.
On return to air, there was an immediate change in breathing pattern; breathing frequency increased above air-breathing values,
roughly to the same maximum level regardless of the level of CO2 the animal had been previously breathing, and tidal volume returned rapidly toward resting (baseline) values. Total ventilation
slowly returned to air breathing values. Administration of CO2 via different routes indicated that inhaled CO2 acted at both upper airway and pulmonary CO2-sensitive receptors to modify breathing pattern without inhibiting breathing overall. Our data suggest that in caiman, high
levels of inspired CO2 promote slow, deep breathing. This will decrease dead-space ventilation and may reduce stratification in the saccular portions
of the lung. 相似文献
116.
Chromoblastomycosis is a chronic and progressive deep mycosis that is usually found in tropical and subtropical areas. Fonsecaea pedrosoi is considered its most frequent etiologic agent and causes a typical granulomatous inflammatory response, whose degree reflects
the immune status of the host. Since macrophages play a fundamental role in the control of the infection, this study aimed
at investigating the production of oxygen reactive specimens, the phagocytic capacity and the production of nitric oxide (NO)
by macrophages employing in vitro assays and an in vivo model of chromoblastomycosis. Our results demonstrated that, during the infection, peritoneal macrophages show an increased
phagocytic capacity and H2O2 production, but also a reduced ability to produce NO. Moreover, F. pedrosoi stimulated H2O2 production in vitro but not the synthesis of NO. The incubation of IFNγ and LPS-stimulated macrophages with melanin, obtained from the fungus,
inhibited NO production. Examination of the liver and spleen of infected animals, at day 30 or 60 following inoculation, showed
a progressive increase in the number and size of granulomas, indicating that macrophages are properly mobilized and activated.
Our data suggest that the inability of the host to clear F. pedrosoi, leading to a chronic disease, is due, at least in part, to the inhibition of NO synthesis by macrophages by fungus-produced
melanin. 相似文献
117.
Jesus LM Abreu PR Almeida MC Brito LC Soares SF de Souza DE Bernardo LC Fonseca AS Bernardo-Filho M 《Acta biologica Hungarica》2006,57(2):191-200
Since ancient times propolis has been employed for many human purposes because to their favourable properties. Blood constituents labeled with technetium-99m (99mTc) have been used in nuclear medicine procedures. Some authors have reported that synthetic or natural drugs can interfere with the labeling of blood constituents with 99mTc. The aim of this work was to evaluate the action of a propolis extract on the labeling of blood elements with 99mTc. Samples of whole blood of male Wistar rats were incubated in sequence with an aqueous propolis extract at different concentrations, stannous chloride and 99mTc, as sodium pertechnetate. Blood samples were centrifuged to separate plasma and blood cells, soluble and insoluble fractions of plasma and blood cells were also separated after precipitation in trichloroacetic acid solution and centrifugation. The radioactivity was counted and the percentage of incorporated radioactivity (%ATI) for each fraction was calculated. The data obtained showed that the aqueous propolis extract used decreased significantly the %ATI in plasma proteins at higher concentration studied. Results suggest that at high concentration the constituents of this extract could alter the labeling of plasma proteins competing with same binding sites of the 99mTc on the plasma proteins or acting as antioxidant compounds. 相似文献
118.
Pierre Neuvial Philippe Hupé Isabel Brito Stéphane Liva élodie Manié Caroline Brennetot Fran?ois Radvanyi Alain Aurias Emmanuel Barillot 《BMC bioinformatics》2006,7(1):264
Background
Array-based comparative genomic hybridization (array-CGH) is a recently developed technique for analyzing changes in DNA copy number. As in all microarray analyses, normalization is required to correct for experimental artifacts while preserving the true biological signal. We investigated various sources of systematic variation in array-CGH data and identified two distinct types of spatial effect of no biological relevance as the predominant experimental artifacts: continuous spatial gradients and local spatial bias. Local spatial bias affects a large proportion of arrays, and has not previously been considered in array-CGH experiments. 相似文献119.
The blood–brain barrier (BBB) is a highly specialized system that controls the exchanges between the blood and the central
nervous system (CNS). This barrier shields the CNS from toxic substances in the blood and provides nutrients to CNS, thus
playing an essential role in the maintenance of homeostasis. The anatomical basis of the BBB is formed by the endothelial
cells of brain microvasculature, with elaborated tight and adherens junctions, which together with pericytes, the basement
membrane, and astrocytes, as well as neurons, microglia and oligodendrocytes form the neurovascular unit. The interaction
between all these components guarantees a proper environment for neural function and a restricted permeability and transport.
Pericytes were initially reported by Rouget in 1873 and since then they have been recognized as an important component of
the BBB, despite the difficulty of their identification. Diverse functions have been assigned to pericytes, including a role
in BBB properties, hemostasis, and angiogenesis, as well as a contractile, immune, and phagocytic function. These cells are
also seen like multipotent cells and so with a great potential for therapy. Here, we review the neurovascular unit composition
and the interplay between the diverse components, addressing pericytes with a particular detail. 相似文献
120.
Gondim DV Costa JL Rocha SS Brito GA Ribeiro Rde A Vale ML 《Canadian journal of physiology and pharmacology》2012,90(4):395-405
This study investigated the antinociceptive and anti-inflammatory effects of electroacupuncture (EA) on zymosan-induced acute arthritis of the rat temporomandibular joint (TMJ). Male Wistar rats were injected with saline or zymosan (control group; 2?mg) into the left TMJ. Low frequency EA (10?Hz, 30?min) was performed at acupoints (LI4, LI11, ST36, ST44) or sham points 2?h after or 1?h before zymosan administration. Mechanical hypernociception was accessed by the electronic Von Frey method after zymosan administration. Rats were sacrificed 6?h after zymosan administration and the joint was removed for histopathological analysis, myeloperoxidase activity assessment, vascular permeability observations, and immunohistochemical verification of inflammatory mediators. The results showed that EA inhibited zymosan-induced hypernociception, compared with the control group and with the sham group (p?< 0.05). The results showed that EA inhibited inflammatory parameters such as neutrophil migration, vascular permeability, and tumour necrosis factor α (TNF-α), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) expression in the TMJ compared with the sham group (p < 0.05). Histopathological analysis showed that EA significantly inhibited edema and periarticular infiltration (p?< 0.05) compared with the control and sham groups. EA at acupoints produced antinociceptive and anti-inflammatory effects on zymosan-induced arthritis in the rat TMJ. 相似文献