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31.
Hela Mahmoudi Rym Kaddour Jun Huang Nawel Nasri Baâtour Olfa Sabah M’Rah Abdelali Hannoufa Mokhtar Lachaâl Zeineb Ouerghi 《Acta Physiologiae Plantarum》2011,33(5):1613-1622
Salt stress perturbs a multitude of physiological processes such as photosynthesis and growth. To understand the biochemical
changes associated with physiological and cellular adaptations to salinity, two lettuce varieties (Verte and Romaine) were
grown in a hydroponics culture system supplemented with 0, 100 or 200 mM NaCl. Verte displayed better growth under 100 mM
NaCl compared to Romaine, but both genotypes registered relatively similar reductions in growth under 200 mM NaCl treatment.
Both varieties showed differences in net photosynthetic activity in the absence of salt and 8 days after salt treatment. These
differences diminished subsequently under prolonged salt stress (14 days). Verte showed enhanced leaf proline and restricted
total cations especially Na+, lesser malondialdehyde (MDA) formation and lignification in the roots under 100 mM NaCl salinity. Membrane damage estimated
by electrolyte leakage increased with elevated salt concentrations in roots of both varieties, but Verte had significantly
lower electrolyte leakage relative to Romaine under 100 mM NaCl. Moreover, Verte also accumulated greater levels of carotenoids
under increasing NaCl concentrations compared to Romaine. Taken together, these findings suggest that the greater tolerance
of Verte to 100 mM NaCl is related to the more restricted accumulation of total cations and toxic Na+ in the roots and enhanced levels of antioxidative metabolites in root and leaf tissue. 相似文献
32.
33.
Afef Bahlous Asma Krir Mehdi Mrad Mouna Bouksila Safa Kalai Osman Kilani Kateb Elhem Cheour El Hela Sahli Nizar Laadhari 《Journal of Medical Biochemistry》2022,41(2):168
BackgroundVitamin D deficiency is one of the most common medical conditions worldwide. In Tunisia, several studies evaluated Vitamin D status, but this was concerning specific populations (pregnant women, obese or diabetic patients and children with asthma). The only study that evaluated Vitamin D status in a healthy Tunisian population was conducted by Meddeb and associeties in 2002. The update of data available, based on the currently recommended limits, is necessary. This study aimed to estimate the prevalence of hypovitaminosis D in a healthy Tunisian population, and correlate the values with potential risk factors.MethodsIt was conducted on 209 Tunisian healthy subjects. Data collected included clinical characteristics and dietary intakes. We measured 25-hydroxyvitamin D (25(OH)D), parathyroid hormone (PTH), glycemia, creatinine, calcium, phosphorus, and alkaline phosphatase concentrations. Hypovitaminosis D was retained for 25(OH)D concentrations <75 nmol/L. Vitamin D deficiency was defined by 25(OH)D concentrations <25 nmol/L.ResultsThe prevalence of hypovitaminosis D and vitamin D deficiency were respectively 92.3% and 47.6%. The main factors that were significantly associated with low vitamin D levels in our multivariate analysis were veiling, living in rural areas and sunscreen use. However, sex, age, socioeconomic level, phototype, solar exposure score, smoking and bone mass index, were not statistically associated with hypovitaminosis D. The study of relationship between vitamin D status and serum PTH levels showed a significative and negative correlation (P < 0.005).ConclusionsGiven the high prevalence of vitamin D, an adapted health policy is essential. A widespread vitamin D supplementation and food fortification seems to be necessary in Tunisia. 相似文献
34.
Mueller C Hutter P Sahli R Bretz A Toutoungi LN Péter O 《FEMS microbiology letters》2000,191(2):199-203
Borrelia garinii is one of the three major Borreliae responsible for Lyme borreliosis in Europe. We have characterized a protein of B. garinii (VS102) and a genomic fragment from the gene encoding this protein was cloned. The DNA sequence of the fragment showed high homology with a known gene of B. burgdorferi sensu stricto. The protein encoded by this gene in B. burgdorferi sensu stricto is a phosphocarrier protein (histidine-containing protein). A mutation T to G polymorphism at codon 57 was found to be specific to B. garinii. A PCR-based approach that allows the rapid detection of this mutation made it possible to specifically discriminate B. garinii from other B. burgdorferi genospecies with high sensitivity and specificity. 相似文献
35.
Bechr Hamrita Hela Ben Nasr Sallouha Gabbouj Noureddine Bouaouina Lotfi Chouchane Karim Chahed 《Molecular biology reports》2011,38(3):1637-1643
Apolipoprotein A1 (ApoA1) is the major apoprotein constituent of high-density lipoprotein that can play important roles in
tumor invasion and metastasis. In the current report, we evaluated the role of the functional ApoA1 polymorphisms (−75 G/A
and +83 C/T) as genetic markers for breast cancer susceptibility and prognosis. We used the polymerase chain reaction and
restriction enzyme digestion (RFLP-PCR) to characterize the variations of the ApoA1 gene in 295 unrelated Tunisian patients
with breast carcinoma and 197 healthy control subjects. No association was found between the +83 C/T genetic variation in
ApoA1 gene and the risk of breast cancer occurrence. The presence of the (+83) T allele appeared however to be associated
with an increased risk of lymph node metastasis occurrence (OR = 2.94; P = 0.01). Furthermore, a positive association was found between ApoA1 −75 A allele carriers and breast cancer risk (OR = 1.57;
P = 0.02). Regarding prognostic indicators, a significant association was found between ApoA1 (−75) A allele carriers and the
premenopausal status of breast cancer patients (OR = 1.73; P = 0.03). Additionally, the presence of the −75 A allele was correlated with the oestrogen receptor status among premenopausal
women (OR = 2.45; P = 0.02). This is the first report on the studies of ApoA1 single nucleotide polymorphisms (SNPs) in breast carcinomas. Our
data suggest that these genetic variations of ApoA1 may represent a marker for the increased risk of breast cancer. 相似文献
36.
L Romdhane R Kefi H Azaiez N Ben Halim K Dellagi S Abdelhak 《Orphanet journal of rare diseases》2012,7(1):52
ABSTRACT: Background Tunisia is a North African country of 10 million inhabitants. The native background population is Berber. However, throughout its history, Tunisia has been the site of invasions and migratory waves of allogenic populations and ethnic groups such as Phoenicians, Romans, Vandals, Arabs, Ottomans and French. Like neighbouring and Middle Eastern countries, the Tunisian population shows a relatively high rate of consanguinity and endogamy that favor expression of recessive genetic disorders at relatively high rates. Many factors could contribute to the recurrence of monogenic morbid trait expression. Among them, founder mutations that arise in one ancestral individual and diffuse through generations in isolated communities. Method We report here on founder mutations in the Tunisian population by a systematic review of all available data from PubMed, other sources of the scientific literature as well as unpublished data from our research laboratory. Results We identified two different classes of founder mutations. The first includes founder mutations so far reported only among Tunisians that are responsible for 30 genetic diseases. The second group represents founder haplotypes described in 51 inherited conditions that occur among Tunisians and are also shared with other North African and Middle Eastern countries. Several heavily disabilitating diseases are caused by recessive founder mutations. They include, among others, neuromuscular diseases such as congenital muscular dystrophy and spastic paraglegia and also severe genodermatoses such as dystrophic epidermolysis bullosa and xeroderma pigmentosa. Conclusion This report provides informations on founder mutations for 73 genetic diseases either specific to Tunisians or shared by other populations. Taking into account the relatively high number and frequency of genetic diseases in the region and the limited resources, screening for these founder mutations should provide a rapid and cost effective tool for molecular diagnosis. Indeed, our report should help designing appropriate measures for carrier screening, better evaluation of diseases burden and setting up of preventive measures at the regional level. 相似文献
37.
Amel?Soltani Hela?Louati Amel?Hanachi Fida?Ben Salem Naceur?Essid Patricia?Aissa Ezzeddine?MahmoudiEmail author Hamouda?Beyrem 《Biologia》2012,67(2):377-383
A microcosm experiment was used to examine the response of nematode in terms of density and diversity at different levels
of permethrin contamination. The sediments were contaminated with three permethrin concentrations [P1: low (5 mg kg−1), P2: medium (25 mg kg−1) and P3: high (250 mg kg−1)] and the effects were evaluated after 30 days. The results from univariate and multivariate analyses showed significant
differences between nematode assemblages from uncontaminated control and those from permethrin treatments. All univariate
indices changed significantly at all the levels of permethrin contamination. In fact, the total nematode abundance (I), Shannon-Weaner index (H′), species richness (d), evenness (J′) and number of species (S) decreased significantly in all the contaminated microcosms. In addition, the results from multivariate analyses of the species
abundance data demonstrated that permethrin affects the responses of nematode species. These significant modifications in
nematode community structures with response to permethrin contamination were the consequences of a different specific tolerance
to this pesticide. Thus, Araeolaimus bioculatus, Calomicrolaimus honestus, Oncholaimus campylocercoides and Theristus pertenuis characterized by increased abundances in all treated replicates, appeared to be “permethrin-resistant” species. Daptonema trabeculosum was eliminated in all the doses tested and seemed to be a very sensitive species to permethrin contamination. 相似文献
38.
Seasonal water quality of shallow and eutrophic Lake Pamvotis, Greece: implications for restoration 总被引:6,自引:2,他引:4
José R. Romero Iphigenia Kagalou Jörg Imberger Dimitra Hela Melina Kotti Aristides Bartzokas Triantafyllos Albanis Nicholaos Evmirides Spiros Karkabounas Joannis Papagiannis Amalia Bithava 《Hydrobiologia》2002,474(1-3):91-105
Lake Pamvotis is a moderately sized (22 km2) shallow (z
avg=4 m) lake with a polymictic stratification regime located in northwest Greece. The lake has undergone cultural eutrophication over the past 40 years and is currently eutrophic (annual averages of FRP=0.07 mg P l-1, TP=0.11 mg P l-1, NH4
+=0.25 mg N l-1, NO3
–=0.56 mg N l-1). FRP and NH4
+ levels are correlated to external loading from streams during the winter and spring, and to internal loading during multi-day periods of summer stratification. Algal blooms occurred in summer (July–August green algae, August–September blue-green algae), autumn (October blue-green algae and diatoms), and winter (February diatoms), but not in the spring (March–June). The phytoplankton underwent brief periods of N- and P-limitation, though persistent low transparency (secchi depth of 60–80 cm) also suggests periods of light limitation. Rotifers counts were highest from mid-summer to early autumn whereas copepods were high in the spring and cladocerans were low in the summer. Removal of industrial and sewage point sources a decade ago resulted in a decrease in FRP. A phosphorus mass balance identified further reductions in external loading from the predominately agricultural catchment will decrease FRP levels further. The commercial fishery and lake hatchery also provides opportunities to control algal biomass through biomanipulation measures. 相似文献
39.
Conner JK Karoly K Stewart C Koelling VA Sahli HF Shaw FH 《The American naturalist》2011,178(4):429-441
Genetic correlations are the most commonly studied of all potential constraints on adaptive evolution. We present a comprehensive test of constraints caused by genetic correlation, comparing empirical results to predictions from theory. The additive genetic correlation between the filament and the corolla tube in wild radish flowers is very high in magnitude, is estimated with good precision (0.85 ± 0.06), and is caused by pleiotropy. Thus, evolutionary changes in the relative lengths of these two traits should be constrained. Still, artificial selection produced rapid evolution of these traits in opposite directions, so that in one replicate relative to controls, the difference between them increased by six standard deviations in only nine generations. This would result in a 54% increase in relative fitness on the basis of a previous estimate of natural selection in this population, and it would produce the phenotypes found in the most extreme species in the family Brassicaceae in less than 100 generations. These responses were within theoretical expectations and were much slower than if the genetic correlation was zero; thus, there was evidence for constraint. These results, coupled with comparable results from other species, show that evolution can be rapid despite the constraints caused by genetic correlations. 相似文献
40.
Jaïdane H Gharbi J Lobert PE Caloone D Lucas B Sané F Idziorek T Romond MB Aouni M Hober D 《Microbiology and immunology》2008,52(1):40-46
Infection of primary cultures of total splenic and thymic cells from BALB/c and C3H/HeN mice with CVB4 E2 and JVB strains has been investigated. The presence of positive-strand viral RNA within cells was determined by semi-nested RT-PCR, and viral replication was attested by detection of intracellular negative-strand viral RNA and by release of infectious particles in culture supernatants. Viral replication occurred with both CVB4 strains to an extent dependent on the genetic background of the host. No interferon-alpha production was detected in the supernatants of CVB4-infected cultures using biological titration. Together these results suggest that infection of splenic and thymic cells can play a role in virus dissemination, and therefore in the pathophysiology of CVB4 infections. 相似文献