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141.
ABSTRACT: INTRODUCTION: Cowden syndrome is a rare cancer predisposition syndrome inherited in an autosomaldominantfashion. The syndrome is characterized by hamartomatous polyps that affectmultiple organs: skin, mucous membranes, thyroid, breast, gastrointestinal tract,endometrium and brain. It is also associated with an increased risk of developing malignancyin many tissues but especially breast, thyroid and endometrium. CASE PRESENTATION: We present the case of a 30-year-old Tunisian woman with mental retardation who presentedto our facility with rectal hamartomatous polyps. Her medical history included fibrocysticdisease of the breast over the last three years. A physical examination revealed macrocephaly,hyperkeratotic papules on the mid-facial skin, palmoplantar keratosis and oral mucosalpapillomatosis. A breast examination revealed nodular breast tissue bilaterally and a diffusethyroid goiter. Our patient was clinically euthyroid. A total thyroidectomy was performed. Ahistopathologic examination revealed thyroid papillary carcinoma. A gastrointestinalevaluation revealed esophageal and gastric polyps. Biopsies showed hyperplastic andadenomatous lesions associated with Helicobacter pylori. A final diagnosis of Cowdensyndrome was made according to the syndrome testing criteria adapted by the US NationalComprehensive Cancer Network. A prophylactic bilateral mastectomy was proposed butrefused by our patient. Our patient was kept under surveillance for breast and colorectalmalignancies. CONCLUSIONS: Early and accurate diagnosis of Cowden syndrome is essential because it is a cancerpredisposition syndrome that carries an increased risk for developing malignancy in manytissues, especially breast and thyroid. For this reason, education regarding the signs andsymptoms of cancer is important. All patients must be screened for malignancies and optionsfor prophylactic mastectomy should be discussed. Guidelines for cancer screening includingsurveillance and management plans for these patients should be distinguished from those ofthe general population, and may lead to a more timely diagnosis and treatment of cancersassociated with this syndrome.  相似文献   
142.
This study aimed to determine the probiotic potential of 100 strains of Lactic Acid Bacteria (LAB) isolated from different intestinal segments of indigenous poultry in Tunisia. The strains were submitted to a battery of standard tests and criteria commonly used for determining their probiotic properties and attributes. The findings revealed that 19 of the isolates exhibited antimicrobial activity against 4 pathogenic bacteria, and that 4 (TN1, TN8, TN7, and TN13) showed good resistance to pH 3 and 5% bovine bile. Three isolates, namely TN1, TN8, and TN13, showed sensitivity to several antibiotics and were, therefore, selected for further enzymatic activity assays. Two isolates, namely TN1 and TN8, showed high efficacy of adhesion to chicken enterocytes. The cytokines released after stimulation by the two isolates showed high anti-inflammatory profiles, with an increased rate of Interleukin-10 (IL-10) production for the TN8 strain. Showing the highest performance, TN8 was submitted to 16S rRNA gene sequencing, which revealed that the strain was of the species Lactobacillus plantarum. Overall, the findings indicate that the Lactobacilli from poultry intestine has a number of promising properties that make it candidate for application as a probiotic additive in poultry industry.  相似文献   
143.
The ultrastructural organization of the spermatozoon of the digenean Hypocreadium caputvadum (Lepocreadioidea: Lepocreadiidae) is described. Live digeneans were collected from Balistes capriscus (Teleostei: Balistidae) from the Gulf of Gabès, Tunisia (Eastern Mediterranean Sea). The mature spermatozoon of H. caputvadum shows several ultrastructural characters such as two axonemes of different lengths exhibiting the classical 9 + “1” trepaxonematan pattern, a nucleus, two mitochondria, granules of glycogen, external ornamentation of the plasma membrane and two bundles of parallel cortical microtubules. Moreover, in the anterior extremity, the second axoneme is partly surrounded by a discontinuous and submembranous layer of electron-dense material. Our study provides new data on the spermatozoon of H. caputvadum in order to improve the understanding of phylogenetic relationships in the Digenea, particularly in the superfamily Lepocreadioidea. In this context, the electron-dense material surrounding one of the axonemes in the anterior spermatozoon extremity constitutes the unique distinguishing ultrastructural character of lepocreadioideans, and it is present in spermatozoa of lepocreadiids, aephnidiogenids and gyliauchenids.  相似文献   
144.
Conventionally, Lepus capensis is considered to range across large parts of Africa, the Middle East, Central and Far East Asia. However, a recent morphological study restricts cape hares tentatively to a small range in the Western Cape Region of South Africa and groups all other L. capensis-type hares from South Africa into a new species: L. centralis. Here, we studied molecular relationships among L. capensis-type hares from South Africa. Phenotypically and morphologically the individuals matched either the newly described L. capensis or L. centralis. We examined 66 hares for allelic variation at 13 microsatellite loci and for sequence variation of the hypervariable domain 1 of the mitochondrial control region. All tree-generating analyses of the currently obtained sequences and all South African cape hare sequences downloaded from GenBank revealed monophyly when compared to sequences of various other Lepus species. A network analysis indicated close evolutionary relationships between hares of the “L. capensis-phenotype” and the “L. centralis-phenotype” (according to Palacios et al. 2008) from the southwest of the Western Cape, relative to their pronounced evolutionary divergence from all other more central, northern, and north-eastern L. capensis-type hares. F-statistics, a Bayesian admixture STRUCTURE model, as well as a principal coordinate analysis of microsatellite data indicated close genetic relationships among all South African L. capensis-type hares studied presently. A coalescence model-based migration analysis for microsatellite alleles indicated gene flow between most of the considered subspecies of cape hare, including L. capensis capensis and L. capensis centralis, theoretically sufficient to balance stochastic drift effects. Concordantly, AMOVA models revealed only little effects of partitioning microsatellite variation into the two suggested morpho-species “L. capensis” and “L. centralis”. Under an “Interbreeding Species Concept” (e.g. a strict or relaxed Biological Species Concept), the current molecular data demonstrate conspecificity of the two proposed morpho-species “L. capensis” and “L. centralis”. Based on the present molecular data the differentiation of subspecies of cape hares from southern Africa is discussed.  相似文献   
145.
Genetic transformation of a biological oxygen demand (BOD)-sensing yeast, Trichosporon cutaneum IFO 10466 was carried out using a plasmid shuttle vector, pAN 7–1, between Escherichia coli and Aspergillus niger and Aspergillus nidulans. The hygromycin B-resistant transformants were obtained with the plasmid by using the spheroplasts. The transformation frequency was up to 70 colonies per g of plasmid DNA. Southern-blot analysis and transformation test of E. coli using DNA extracts from hygromycin B-resistant transformants of IFO 10466 indicated that pAN 7–1 existed independently in the cells without integration into the chromosome. These results suggest that pAN 7–1 has potential availability for introduction and expression of the external gene such as a bioluminescence gene, lux or luc, to create a luminous yeast for BOD sensing. © Rapid Science Ltd. 1998  相似文献   
146.
Samraoui (J Insect Conserv.  https://doi.org/10.1007/s10841-017-9966-2, 2017) claims that he shows evidence that our conservation plan of Urothemis edwardsii has failed and that natural dispersal was the only cause of the recent rapid range expansion of the species in Northeast Algeria. Here, we show that his analysis is biased, many of his arguments are erroneous and strongly contradictory, many key studies are dismissed, and the few data used as evidence to refute our conclusions rather confirm them. We also provide data to prove that our conservation plan did not cause any harm to the source population by comparing exuviae-based estimation of population size in 2012 and 2016. We discuss the need for future monitoring and management and highlight that the recommendations of Samraoui (J Insect Conserv, 2017) are misleading, and thus are unlikely to bring us closer to an effective long-term conservation of the species in the region. Beyond our criticism, we explain why we should not dismiss the direct and indirect implications of final instar larvae translocation in successful colonization of odonates in particular, which could also be applied to aquatic insects in general.  相似文献   
147.
Glucose transport by mixed ruminal bacteria from a cow.   总被引:1,自引:1,他引:0       下载免费PDF全文
H Kajikawa  M Amari    S Masaki 《Applied microbiology》1997,63(5):1847-1851
The glucose transport of mixed ruminal bacteria harvested from a holstein cow fed 5.0 kg of Italian ryegrass and 1.5 kg of flaked corn a day was investigated. The Eadie-Hofstee plot characterized two transport systems: a high-affinity, low-velocity system and a low-affinity, high-velocity system. The former system (K(m) = 16 microM; Vmax = 2.2 nmol/min/mg of protein) is considered dominant under this feeding condition based on the glucose concentration in the rumen (< 1 mM). In light of the facts that the protonophore SF6847 and the lipophilic triphenylmethyl phosphonium ion had no effect on the high-affinity system and an artificially generated proton gradient and electrical potential across the cell membrane did not increase glucose transport, a proton motive force is not be involved in the system. On the other hand, from the facts that chlorhexidine inhibited about 90% of the high-affinity system while iodoacetate showed no significant effect, and a high phosphoenolpyruvate-dependent phosphorylation of glucose was actually shown, the phosphoenolpyruvate-dependent phosphotransferase system is considered the main system in the high-affinity system. Moreover, as shown by the facts that harmaline inhibited about 30% of the high-affinity system and the artificially generated sodium gradient across the cell membrane significantly stimulated glucose transport, this system also includes sodium symport to some degree. The high-affinity system was sensitive to a decrease in pH (< 6.5) and was inhibited by the presence of sucrose, mannose, and fructose.  相似文献   
148.
Topographic connections are found in many parts of the vertebrate nervous systems, known for example as retinotopy. The self-organizing ability of Hebb type modifiable synapses plays an important role in forming, at least in refining, the topographic connections. We present a mathematical analysis of a revised version of the Willshaw-Malburg model of topographic formation, solving the equations of synaptic self-organization coupled with the field equation of neural excitations. The equilibrium solutions are obtained and their stability is studied. It is proved that two cases exist depending on parameters. In one case, the smooth topographic organization is obtained as a stable equilibrium of the equations. In the other case, this solution becomes unstable, and instead the topographic organization with columnar microstructures appears. This might explain the columnar structures in the cerebrum. The theory is confirmed by computer simulated experiments.  相似文献   
149.
The aims of this study were to investigate the effects of water deficit and recovery on growth, photosynthesis and water relations in four Medicago laciniata populations from saharian (Ml-90), inferior arid (Ml-204), superior arid (Ml-306) and semi-arid (Ml-376) Tunisian regions. After 28 d of sowing with ample irrigation, the plants were subjected to 4 water regimes: optimal irrigation (100% of field capacity, FC), moderate drought (75% FC), severe drought (35% FC) and rewatering (plants submitted to 35% FC during 7 d, afterwards the plants were rewatered to 100% FC). Harvest was carried out after 28 d of treatments. The drought tolerance in M. laciniata populations was found to be increased particularly with increasing temperatures of collection site of the population. The Ml-204 and Ml-90 populations used mainly physiological strategies for survival under moderate water shortage. Higher severe drought tolerance in both signaled populations would be related to their lower photosynthesis metabolic impairment, relatively higher leaf RWC and greater osmotic potential decrease. The results suggest that plants with low values of leaf features are likely to maintain higher leaf RWC under sever drought. The largest decrease of osmotic potential was found associated with the solute accumulations such as proline and K+.  相似文献   
150.
This study examined the effects of Ramadan fasting on anaerobic performances and their diurnal fluctuations. In a balanced and randomized study design, 12 subjects were measured for maximal power (Pmax; force-velocity test), peak power (Ppeak), and mean power (Pmean) with the Wingate test at 07:00, 17:00, and 21:00 h on four different occasions: one week before Ramadan (BR), the second week of Ramadan (SWR), the fourth week of Ramadan (ER), and two weeks after Ramadan (AR). There was an interval of 28 h between any two successive tests. Oral temperature was measured before each test. Under each condition, the results showed a time-of-day effect on oral temperature. Analysis of variance revealed a significant (Ramadan×time-of-day of test) interaction effect on Pmax. This variable improved significantly from morning to evening before Ramadan (1.1±0.2 W · kg-1), during the second week of Ramadan (0.6±0.2 W · kg-1), and two weeks after the end of Ramadan (0.9±0.2 W · kg-1). However, daily fluctuations disappeared during the fourth week of Ramadan. For Ppeak and Pmean, there was no significant Ramadan×test-time interaction. These variables improved significantly from morning to evening before Ramadan ([1±0.3 W · kg-1] for Ppeak and [1.7±1.6 W · kg-1] for Pmean) and in the second week of Ramadan ([0.9±0.6 W · kg-1] for Ppeak and [1.7±1.5 W · kg-1] for Pmean). However, they were not affected by time-of-day in the fourth week of Ramadan. Considering the effect of Ramadan on anaerobic performances, in comparison with before Ramadan, no significant difference was observed during Ramadan at 07:00 h. The variables were significantly lower in the second week of Ramadan and in the fourth week of Ramadan at 17:00 h and 21:00 h. Pmean was not affected during the second week of Ramadan. In conclusion, the time-of-day effect on anaerobic power variables tends to disappear during Ramadan. In comparison with the period before Ramadan, anaerobic performances were unaffected in the morning but impaired in the evening during Ramadan.  相似文献   
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