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91.
Annabi-Trabelsi Neila Daly-Yahia Mohamed Néjib Belmonte Genuario Aleya Lotfi Ayadi Habib 《Journal of thermal biology》2012
The daily Egg Production Rate (EPR) of the three Acartiidae copepods namely Acartia clausi, Paracartia latisetosa and Paracartia grani in the North Lagoon of Tunis was compared to temperature and food availability every season from March, 2003 to February, 2004 corresponding to the major seasonal peaks of their abundance and over a 20-days period. The daily EPR was evaluated by assuming a direct correlation with chlorophyll a, particulate organic carbon (POC), and some easily extractable macromolecular compounds from the seston, such as proteins, carbohydrates and lipids. The results showed significant differences in EPR between seasons and species. Temperature and salinity negatively affected the fecundity of A. clausi and positively that of P. latisetosa and P. grani. The A. clausi EPR was supported by chlorophyll a and sestonic proteins while that of P. latisetosa and P. grani correlated with POC suggesting that these two taxa feed on microzooplankton and detritus more than on phytoplankton. Overall, EPR data showed potential population recruitment evidently the highest in P. latisetosa in summer, P. grani in autumn and A. clausi in winter. Our results indicate that temperature and food quality are the determining factors of both abundance and reproduction of the copepods under study. 相似文献
92.
Improved enzyme production by bio-pellets of Aspergillus niger: targeted morphology engineering using titanate microparticles 总被引:1,自引:0,他引:1
Driouch H Hänsch R Wucherpfennig T Krull R Wittmann C 《Biotechnology and bioengineering》2012,109(2):462-471
The present study describes the design of bio-pellet morphologies of the industrial working horse Aspergillus niger strains in submerged culture. The novel approach recruits the intended addition of titanate microparticles (TiSiO(4), 8 μm) to the growth medium. As tested for two recombinant strains producing fructofuranosidase and glucoamylase, the enzyme titer by the titanate-enhanced cultures in shake flasks was increased 3.7-fold to 150 U/mL (for fructofuranosidase) and 9.5-fold to 190 U/mL (for glucoamylase) as compared to the control. This could be successfully utilized for improved enzyme production in stirred tank reactors. Stimulated by the particles, the achieved final glucoamylase activity of 1,080 U/mL (fed-batch) and 320 U/mL (batch) was sevenfold higher as compared to the conventional processes. The major reason for the enhanced production was the close association between the titanate particles and the fungal cells. Already below 2.5 g/L the micromaterial was found inside the pellets, including single particles embedded as 50-150 μm particle aggregates in the center resulting in core shell pellets. With increasing titanate levels the pellet size decreased from 1,700 μm (control) to 300 μm. Fluorescence based resolution of GFP expression revealed that the large pellets of the control were only active in a 200 μm surface layer. This matches with the critical penetration depth for nutrients and oxygen typically observed for fungal pellets. The biomass within the titanate derived fungal pellets, however, was completely active. This was due a reduced thickness of the biomass layer via smaller pellets as well as the core shell structure. Moreover, also the created loose inner pellet structure enabled a higher mass transfer and penetration depths for up to 500 μm. The creation of core-shell pellets has not been achieved previously by the addition of microparticles, for example, made of talc or alumina. Due to this, the present work opens further possibilities to use microparticles for tailor-made morphology design of filamentous fungi, especially for pellet based processes which have a long and strong industrial relevance for industrial production. 相似文献
93.
Haymaker CL Guloglu FB Cascio JA Hardaway JC Dhakal M Wan X Hoeman CM Zaghouani S Rowland LM Tartar DM VanMorlan AM Zaghouani H 《Journal of immunology (Baltimore, Md. : 1950)》2012,188(7):3208-3216
The earliest thymic progenitors (ETPs) were recently shown to give rise to both lymphoid and myeloid cells. Whereas the majority of ETPs are derived from IL-7Rα-positive cells and give rise exclusively to T cells, the origin of the myeloid cells remains undefined. In this study, we show both in vitro and in vivo that IL-13Rα1(+) ETPs yield myeloid cells with no potential for maturation into T cells, whereas IL-13Rα1(-) ETPs lack myeloid potential. Moreover, transfer of lineage-negative IL-13Rα1(+) bone marrow stem cells into IL-13Rα1-deficient mice reconstituted thymic IL-13Rα1(+) myeloid ETPs. Myeloid cells or macrophages in the thymus are regarded as phagocytic cells whose function is to clear apoptotic debris generated during T cell development. However, the myeloid cells derived from IL-13Rα1(+) ETPs were found to perform Ag-presenting functions. Thus, IL-13Rα1 defines a new class of myeloid restricted ETPs yielding APCs that could contribute to development of T cells and the control of immunity and autoimmunity. 相似文献
94.
For a given set L of species and a set T of triplets on L, we seek to construct a phylogenetic network which is consistent with T i.e. which represents all triplets of T. The level of a network is defined as the maximum number of hybrid vertices in its biconnected components. When T is dense, there exist polynomial time algorithms to construct level-0,1 and 2 networks (Aho et al., 1981; Jansson, Nguyen and Sung, 2006; Jansson and Sung, 2006; Iersel et al., 2009). For higher levels, partial answers were obtained in the paper by Iersel and Kelk (2008), with a polynomial time algorithm for simple networks. In this paper, we detail the first complete answer for the general case, solving a problem proposed in Jansson and Sung (2006) and Iersel et al. (2009). For any k fixed, it is possible to construct a level-k network having the minimum number of hybrid vertices and consistent with T, if there is any, in time O(T(k+1)n([4k/3]+1)). 相似文献
95.
DB Haque DK Rahman DA Hoque DA Hasan DR Chowdhury DS Khan DM Alam PM Habib PQ Mohammad 《BMC neurology》2012,12(1):82
ABSTRACT: BACKGROUND: To determine the differences of precipitating and relieving factors between migraine and tension type headache METHODS: This is a cross sectional study. We retrospectively reviewed the records of 250 migraine patients and 250 patients diagnosed as tension type headache from the specialized headache clinic in Dept. of Neurology, Dhaka Medical College Hospital. Data were collected through a predesigned questionnaire containing information on age, sex, social status and a predetermined list of precipitating and relieving factors. RESULTS: In this study, the female patients predominated (67%). Most of the patients were within 21--30 years age group (58.6%). About 58% of them belonged to middle class families. The common precipitating factors like stress, anxiety, activity, journey, reading, cold and warm were well distributed among both the migraine and tension type headache (TTH) patients. But significant difference was demonstrated for fatigue (p < 0.05), sleep deprivation (p < 0.05), sunlight (p < 0.01) and food (p < 0.05), which were common among migraineurs. In consideration of relieving factors of pain, different maneuvers were commonly tried by migraineurs and significant difference were observed for both analgesic drug and massage (p < 0.05), which relieved migraine headache. But maneuvers like sleep, rest and posture were used by both groups. CONCLUSION: The most frequent precipitating factors for headache appear to be identical for both migraine and TTH patients. Even though some factors like fatigue, sleep deprivation, sunlight and food significantly precipitate migraine and drug, massage are effective maneuver for relieving pain among migrianeurs. 相似文献
96.
The purpose of this study was to utilize near-infrared (NIR) spectroscopy and near-infrared chemical imaging (NIR-CI) as non-invasive techniques to evaluate the drug loading in letrozole-loaded PLGA nanoparticle formulations prepared by the emulsification–solvent evaporation method. A Plackett–Burman design was applied to evaluate the main effects of amount of drug (X1), amount of polymer (X2), stirring rate (X3), emulsifier concentration (X4), organic to aqueous phase volume ratio (X5), type of organic solvent (X6), and homogenization time (X7) on drug entrapment efficiency. The influence of three different spectral pretreatment methods (multiplicative scatter correction, standard normal variate, and Savitzky–Golay second derivative transformation with third-order polynomial) and two different regression methods (PLS regression and principal component regression (PCR)) on model prediction ability were compared. PLS of spectra that were pretreated with Savitzky–Golay second derivative transformation provided better model prediction than PCR as it revealed better linear correlation (correlation coefficient of 0.991) for both calibration and prediction models. Relatively low values of root mean square errors of calibration (RMSEC = 0.748) and prediction (RMSEP = 0.786) and low standard errors of calibration (SEC = 0.758) and prediction (SEP = 0.589) suggested good predictability for estimation of the loading of letrozole in PLGA nanoparticles. NIR-CI analysis also revealed mutual homogenous distribution of both polymer and drug and was capable of clearly distinguishing the 12 formulations both quantitatively and qualitatively. In conclusion, NIR and NIR-CI could be potentially used to characterize anticancer drug-loaded nanoparticulate matrix.KEY WORDS: imaging, letrozole, nanoparticle, near-infrared, PCR, PLGA, PLS 相似文献
97.
D Coggon G Ntani KT Palmer VE Felli R Harari LH Barrero SA Felknor D Gimeno A Cattrell C Serra M Bonzini E Solidaki E Merisalu RR Habib F Sadeghian M Kadir SS Warnakulasuriya K Matsudaira B Nyantumbu MR Sim H Harcombe K Cox MH Marziale LM Sarquis F Harari R Freire N Harari MV Monroy LA Quintana M Rojas EJ Salazar Vega EC Harris S Vargas-Prada JM Martinez G Delclos FG Benavides M Carugno MM Ferrario AC Pesatori L Chatzi P Bitsios M Kogevinas K Oha T Sirk A Sadeghian RJ Peiris-John N Sathiakumar 《PloS one》2012,7(7):e39820
Background
The CUPID (Cultural and Psychosocial Influences on Disability) study was established to explore the hypothesis that common musculoskeletal disorders (MSDs) and associated disability are importantly influenced by culturally determined health beliefs and expectations. This paper describes the methods of data collection and various characteristics of the study sample.Methods/Principal Findings
A standardised questionnaire covering musculoskeletal symptoms, disability and potential risk factors, was used to collect information from 47 samples of nurses, office workers, and other (mostly manual) workers in 18 countries from six continents. In addition, local investigators provided data on economic aspects of employment for each occupational group. Participation exceeded 80% in 33 of the 47 occupational groups, and after pre-specified exclusions, analysis was based on 12,426 subjects (92 to 1018 per occupational group). As expected, there was high usage of computer keyboards by office workers, while nurses had the highest prevalence of heavy manual lifting in all but one country. There was substantial heterogeneity between occupational groups in economic and psychosocial aspects of work; three- to five-fold variation in awareness of someone outside work with musculoskeletal pain; and more than ten-fold variation in the prevalence of adverse health beliefs about back and arm pain, and in awareness of terms such as “repetitive strain injury” (RSI).Conclusions/Significance
The large differences in psychosocial risk factors (including knowledge and beliefs about MSDs) between occupational groups should allow the study hypothesis to be addressed effectively. 相似文献98.
J Al Suwaidi K Al Habib N Asaad R Singh A Hersi H Al Falaeh S Al Saif A Al-Motarreb W Almahmeed K Sulaiman H Amin J Al-Lawati NQ Al-Sagheer AA Alsheikh-Ali AM Salam 《BMC cardiovascular disorders》2012,12(1):64
ABSTRACT: BACKGROUND: Stroke is a potential complication of acute coronary syndrome (ACS). The aim of this study was to identify the prevalence, risk factors predisposing to stroke, in-hospital and 1-year mortality among patients presenting with ACS in the Middle East. METHODS: For a period of 9 months in 2008 to 2009, 7,930 consecutive ACS patients were enrolled from 65 hospitals in 6 Middle East countries. RESULTS: The prevalence of in-hospital stroke following ACS was 0.70%. Most cases were ST segment elevation MI-related (STEMI) and ischemic stroke in nature. Patients with in-hospital stroke were 5 years older than patients without stroke and were more likely to have hypertension (66% vs. 47.6%, P = 0.001). There were no differences between the two groups in regards to gender, other cardiovascular risk factors, or prior cardiovascular disease. Patients with stroke were more likely to present with atypical symptoms, advanced Killip class and less likely to be treated with evidence-based therapies. Independent predictors of stroke were hypertension, advanced killip class, ACS type --STEMI and cardiogenic shock. Stroke was associated with increased risk of in-hospital (39.3% vs. 4.3%) and one-year mortality (52% vs. 12.3%). CONCLUSION: There is low incidence of in-hospital stroke in Middle-Eastern patients presenting with ACS but with very high in-hospital and one-year mortality rates. Stroke patients were less likely to be appropriately treated with evidence-based therapy. Future work should be focused on reducing the risk and improving the outcome of this devastating complication. 相似文献
99.
Reversal of neuromuscular blockage induced by steroidal neuromuscular blocking agents such as rocuronium can be achieved using
normal dose of sugammadex, which has been shown to be very effective for such reversal. In this study, we determined the effects
of sugammadex on calcineurin immunoreactivity by examining the histopathological and histochemical structure of rat testis
cells after neuromuscular blockage. Moreover, the regional distribution levels of calcineurin immunopositive testes cells
were investigated. Eighteen adult male, Sprague–Dawley rats were divided into one control and two study groups. Study groups
1 and 2 rats received sugammadex at doses of 16 and 96 mg kg−1 i.v., respectively, after rocuronium treatment (mg kg−1 i.v.). The control group received intravenous 0.9% NaCl 1 ml. i.v without any drug. Our study demonstrates that sugammadex
is safe and effective for reversal of rocuronium effects in rats, as well as in other animals and humans. Furthermore, histopathological
examination indicates that high levels of sugammadex–rocuronium complexes accumulate a little in testis tissue. We found that
rocuronium-sugammadex complexes were remained in circulation for a long time resulting in a decrease in interstitial space,
testis size, germ cell numbers and Leydig cell numbers. Calcineurin immunoreactivity was higher in the experimental groups
than the control group due to increase of calcium level. The results suggest that sugammadex–rocuronium complexes are cause
histopathological and immunohistochemical changes in testis interstitial tissues, as well as changes in sperm density and
germ cell number. 相似文献
100.
Yu P Haymaker CL Divekar RD Ellis JS Hardaway J Jain R Tartar DM Hoeman CM Cascio JA Ostermeier A Zaghouani H 《Journal of immunology (Baltimore, Md. : 1950)》2008,181(1):73-80
Lately, it has become clear that regulatory T cells (Tregs) play a major role in the maintenance of peripheral tolerance and control of autoimmunity. Despite these critical functions, the process underlying the development of Tregs remains largely undefined. Herein, altered peptide ligand (APL) variants derived from the proteolipid protein-1 (PLP1) epitope were expressed on immunoglobulins (Igs) and the resulting Ig-APLs were used to deliver the APLs from mother to fetus through the maternal placenta to influence thymic T cell selection. This delivery system was then adapted to the SJL/J mouse, a strain that expresses only the DM20 form of PLP, which lacks the dominant PLP1 epitope in the thymus during fetal and neonatal development. This model, which restores thymic T cell selection for PLP1, was then used to determine whether affinity plays a role in the development of Tregs. The findings show that fetal exposure to low-affinity peptide ligand was unable to drive development of Tregs while variants with higher affinity to the TCR resulted in significant seeding of the periphery with mature, naive Tregs. Thus, contrary to pathogenic T cells, Tregs require avid TCR-ligand interaction to undergo thymic development and maturation. 相似文献