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31.

Introduction  

The aim of this study was to investigate whether serum biomarker levels of C2C, C1,2C, CS846, and CPII can predict the long-term course of disease activity and radiographic progression early in the disease course of rheumatoid arthritis (RA).  相似文献   
32.
Regulation by PRL of aromatase (P450arom) mRNA and protein and estradiol (E) biosynthesis was examined in granulosa cells during early stages of luteinization in vitro and in vivo. PRL caused a dose-dependent (10-1000 ng/ml) decrease in P450arom mRNA and E biosynthesis (greater than 99%) in luteinized rat granulosa cells in vitro, even when the cells were cultured in the presence of insulin and hydrocortisone (hormones known to synergize with PRL to induce proteins in mammary tissue) or in the presence of forskolin (a nonhormonal stimulator of cAMP). PRL also prevented the marked increases in aromatase mRNA and E biosynthesis stimulated by FSH and forskolin in nonluteinized preovulatory granulosa cells in culture. These effects of PRL on granulosa cells in culture were specific for aromatase and were not observed for other proteins, such as cholesterol side-chain cleavage cytochrome P450 (P450scc) and alpha 2-macroglobulin. PRL also decreased P450arom mRNA and protein during the early stages of luteinization in vivo. PRL administered to rats beginning day 1 postovulation to mimic hormone release during pseudopregnancy reduced the progressive increase in P450arom mRNA occurring in corpora lutea on days 3-4 in ovulated rats not treated with PRL. CB 154, a dopamine agonist that inhibits pituitary release of PRL, caused P450arom mRNA and protein to decrease 50% if given to pregnant rats on days 8-10 of gestation, but increased P450arom mRNA and protein if given to pregnant rats on days 10-12 of gestation. These diverse effects of PRL in pregnancy suggest that placental factors may modify the response of luteal cells to PRL during gestation.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
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34.
We present a theory of the origin and evolution of infant-directed song, a form of music found in many cultures. After examining the ancestral ecology of parent-infant relations, we propose that infant-directed song arose in an evolutionary arms race between parents and infants, stemming from the dynamics of parent-offspring conflict. We describe testable predictions that follow from this theory, consider some existing evidence for them, and entertain the possibility that infant-directed song could form the basis for the development of other, more complex forms of music.  相似文献   
35.
Background: The frizzled (fz) gene of Drosophila encodes the founding member of the large family of receptors for the Wnt family of signaling molecules. It was originally studied in the adult epidermis, where it plays a key role in the generation of tissue polarity. Mutations in components of the fz signal transduction pathway disrupt tissue polarity; on the wing, hairs normally point distally but their polarity is altered by these mutations.Results: We devised a method to induce a gradient of fz expression with the highest levels near the distal wing tip. The result was a large area of proximally pointing hairs in this region. This reversal of polarity was seen when fz expression was induced just before the start of hair morphogenesis when polarity is established, suggesting that the gradient of Fz protein acted fairly directly to reverse hair polarity. A similar induction of the dishevelled (dsh) gene, which acts cell autonomously and functions downstream of fz in the generation of tissue polarity, resulted in a distinct tissue polarity phenotype, but no reversal of polarity; this argues that fz signaling was required for polarity reversal. Furthermore, the finding that functional dsh was required for the reversal of polarity argues that the reversal requires normal fz signal transduction.Conclusions: The data suggest that cells sense the level of Fz protein on neighboring cells and use this information in order to polarize themselves. A polarizing signal is transmitted from cells with higher Fz levels to cells with lower levels. Our observations enable us to propose a general mechanism to explain how Wnts polarize target cells.  相似文献   
36.
Summary A new, fully computerized method for the measurement and analysis of dinoflagellate bioluminescence has been developed and applied to the spontaneous light emission ofGonyaulax polyedra. This light emission consists of a low-level steady glow, and occasional superimposed flashes. The instrumentation distinguishes the two components and records them separately; both exhibit circadian rhythmicity. In this paper we describe the method in detail, and show results for flashing and glow measured under light: dark cycles and under constant light of different intensities. Under constant dim light at 19°C, both rhythms exhibit two peaks during a circadian cycle; the minor ones occur approximately nine hours before the major ones. Under these conditions the major flashing peak occurs early during the subjective night, and the major glow peak at the end, about nine hours later. However, the relative phase angle between glow and flashing peaks varies with light intensity, being as little as 220 min (3.7 h) in the dark under light-dark entrained conditions, to as much as 700 min (11.7 h) in dim light under free-running conditions. The ambient light intensity also affects differentially the amount of light emitted in the two modes of spontaneous luminescence. These results suggest that the controls for the two processes must at some point diverge.  相似文献   
37.
Sans résuméI. Analyse électrocapillaire des matières colorantes. Rev. gén. Mat. Col. 1926 Vol. 30 pp 34–45II. Phénomènes électrocapillaires et le problème du cancer. Arch. Med. Exper. 1926 Vol. I p 381III. Phénomènes électrocapillaires et l'antagonismes microbiens. Bol. Istituto Sier. Milano 1927 Vol. VI p 313.  相似文献   
38.

Background

Potential biomarkers to aid diagnosis and therapy need to be identified for Amyotrophic Lateral Sclerosis, a progressive motor neuronal degenerative disorder. The present study was designed to identify the factor(s) which are differentially expressed in the cerebrospinal fluid (CSF) of patients with sporadic amyotrophic lateral sclerosis (SALS; ALS-CSF), and could be associated with the pathogenesis of this disease.

Results

Quantitative mass spectrometry of ALS-CSF and control-CSF (from orthopaedic surgical patients undergoing spinal anaesthesia) samples showed upregulation of 31 proteins in the ALS-CSF, amongst which a ten-fold increase in the levels of chitotriosidase-1 (CHIT-1) was seen compared to the controls. A seventeen-fold increase in the CHIT-1 levels was detected by ELISA, while a ten-fold elevated enzyme activity was also observed. Both these results confirmed the finding of LC-MS/MS. CHIT-1 was found to be expressed by the Iba-1 immunopositive microglia.

Conclusion

Elevated CHIT-1 levels in the ALS-CSF suggest a definitive role for the enzyme in the disease pathogenesis. Its synthesis and release from microglia into the CSF may be an aligned event of neurodegeneration. Thus, high levels of CHIT-1 signify enhanced microglial activity which may exacerbate the process of neurodegeneration. In view of the multifold increase observed in ALS-CSF, it can serve as a potential CSF biomarker for the diagnosis of SALS.  相似文献   
39.
Comparison of Methods for Tuberculosis Bacteriology   总被引:6,自引:2,他引:6       下载免费PDF全文
To improve efficiency of isolation of tubercle bacilli from clinical specimens, the following recommendations are presented. (i) Employ multiple specimens consisting of a combination of morning sputums for the early detection of positives, along with 24-hr sputum pools for the greatest total yield of positives. (ii) When timing is rigorously controlled, Zephiran-trisodium phosphate and sodium hydroxide-acetylcysteine are comparable, but if timing cannot rigidly be controlled, employ the Zephiran-trisodium phosphate digestion procedure to allow the greatest freedom in exposure time with the lowest kill rate to tubercle bacilli. (iii) Employ both an agar medium incubated in 5% CO2, for the early detection of positives as well as positives in the presence of contaminants, and an egg medium, preferably with CO2, to increase the yield of positives.  相似文献   
40.

Background  

Parkinson's disease (PD) is the second most common neurodegenerative disorder. One of the most widely used techniques to diagnose PD is a Single Photon Emission Computer Tomography (SPECT) scan to visualise the integrity of the dopaminergic pathways in the brain. Despite this there remains some discussion on the value of SPECT in the differential diagnosis of PD. We did a meta-analysis of all the existing literature on the diagnostic accuracy of both pre- and post-synaptic SPECT imaging in the differential diagnosis of PD.  相似文献   
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