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71.
Gideon Y. Stein Gabriel Herscovici Roman Korenfeld Shlomi Matetzky Shmuel Gottlieb Danny Alon Natalie Gevrielov-Yusim Zaza Iakobishvili Shmuel Fuchs 《PloS one》2014,9(1)
Background
Type-II MI is defined as myocardial infarction (MI) secondary to ischemia due to either increased oxygen demand or decreased supply. This categorization has been used for the last five years, yet, little is known about patient characteristics and clinical outcomes. In the current work we assessed the epidemiology, causes, management and outcomes of type II MI patients.Methods
A comparative analysis was performed between patients with type-I and type-II MI who participated in two prospective national Acute Coronary Syndrome Israeli Surveys (ACSIS) performed in 2008 and 2010.Results
The surveys included 2818 patients with acute MI of whom 127 (4.5%) had type-II MI. The main causes of type-II MI were anemia (31%), sepsis (24%), and arrhythmia (17%). Patients with type-II MI tended to be older (75.6±12 vs. 63.8±13, p<0.0001), female majority (43.3% vs. 22.3%, p<0.0001), had more frequently impaired functional level (45.7% vs. 17%, p<0.0001) and a higher GRACE risk score (150±32 vs. 110±35, p<0.0001). Patients with type-II MI were significantly less often referred for coronary interventions (36% vs. 89%, p<0.0001) and less frequently prescribed guideline-directed medical therapy. Mortality rates were substantially higher among patients with type-II MI both at thirty-day (13.6% vs. 4.9%, p<0.0001) and at one-year (23.9% vs. 8.6%, p<0.0001) follow-ups.Conclusions
Patients with type-II compared to type-I MI have distinct demographics, increased prevalence of multiple comorbidities, a high-risk cardiovascular profile and an overall worse outcome. The complex medical condition of this cohort imposes a great therapeutic challenge and specific guidelines with recommended medical treatment and invasive strategies are warranted. 相似文献72.
73.
The geography of snake reproductive mode: a global analysis of the evolution of snake viviparity 下载免费PDF全文
74.
Nitric oxide (NO) is a critical biological mediator involved in numerous diseases. However, the short lifetime of this molecule in biological conditions can make its study in situ complicated. Here, we review some recent results on the role of NO in angiogenesis, obtained using a biocompatible microelectrode array. This simple system allowed for the quick and easy quantification of NO released from cells grown directly on the surface of the sensor. We have used this technology to demonstrate that angiogenin induces NO release, and to partially elucidate its intracellular transduction pathway. 相似文献
75.
Irradiation of puparia in Mediterranean fruit fly, Ceratitis capitata (Wiedemann), sterile insect release programs can negatively affect adult fly performance. Emergence, survivorship, lure attraction, and mating competition tests were performed on irradiated and unirradiated Mediterranean fruit flies in Hawaii. Unirradiated flies of the Vienna-7 (tsl) strain had higher emergence, flight ability, and survivorship compared with irradiated flies. In general, unirradiated flies were more responsive to trimedlure, but this effect was not consistent for all strains at every age. Laboratory strains, of both unirradiated and irradiated flies, responded to trimedlure at a younger age than wild flies, which may be a result of inadvertent selection for decreased development time in laboratory-reared flies. Mating competition tests with irradiated and unirradiated flies showed no significant differences. Costs associated with the irradiation process and the development of alternative control techniques are discussed. 相似文献
76.
77.
It has been known for some time that bicarbonate reverses the inhibition, by formate under HCO3
--depletion conditions, of electron transport in thylakoid membranes. It has been shown that the major effect is on the electron acceptor side of photosystem II, at the site of plastoquinone reduction. After presenting a historical introduction, and a minireview of the bicarbonate effect, we present a hypothesis on how HCO3
- functions in vivo as (a) a proton donor to the plastoquinone reductase site in the D1-D2 protein; and (b) a ligand to Fe2+ in the QA-Fe-QB complex that keeps the D1-D2 proteins in their proper functional conformation. They key points of the hypothesis are: (1) HCO3
- forms a salt bridge between Fe2+ and the D2 protein. The carboxyl group of HCO3
- is a bidentate ligand to Fe2+, while the hydroxyl group H-bonds to a protein residue. (2) A second HCO3
- is involved in protonating a histidine near the QB site to stabilize the negative charge on QB. HCO3
- provides a rapidly available source of H+ for this purpose. (3) After donation of a H+, CO3
2- is replaced by another HCO3
-. The high pKa of CO3
2- ensures rapid reprotonation from the bulk phase. (4) An intramembrane pool of HCO3
- is in equilibrium with a large number of low affinity sites. This pool is a H+ buffering domain functionally connecting the external bulk phase with the quinones. The low affinity sites buffer the intrathylakoid [HCO3
-] against fluctuations in the intracellular CO2. (5) Low pH and high ionic strength are suggested to disrupt the HCO3
- salt bridge between Fe2+ and D2. The resulting conformational change exposes the intramembrane HCO3
- pool and low affinity sites to the bulk phase.Two contrasting hypotheses for the action of formate are: (a) it functions to remove bicarbonate, and the low electron transport left in such samples is due to the left-over (or endogenous) bicarbonate in the system; or (b) bicarbonate is less of an inhibitor and so appears to relieve the inhibition by formate. Hypothesis (a) implies that HCO3
- is an essential requirement for electron transport through the plastoquinones (bound plastoquinones QA and QB and the plastoquinone pool) of photosystem II. Hypothesis (b) implies that HCO3
- does not play any significant role in vivo. Our conclusion is that hypothesis (a) is correct and HCO3
- is an essential requirement for electron transport on the electron acceptor side of PS II. This is based on several observations: (i) since HCO3
-, not CO2, is the active species involved (Blubaugh and Govindjee 1986), the calculated concentration of this species (220 M at pH 8, pH of the stroma) is much higher than the calculated dissociation constant (Kd) of 35–60 M; thus, the likelihood of bound HCO3
- in ambient air is high; (ii) studies on HCO3
- effect in thylakoid samples with different chlorophyll concentrations suggest that the left-over (or endogenous) electron flow in bicarbonate-depleted chloroplasts is due to left-over (or endogenous) HCO3
- remaining bound to the system (Blubaugh 1987).Abbreviations DCMU
3-(3,4-dichlorophenyl)-1, 1-dimethylurea (common name: diuron)
- PSII
photosystem II
- QA
first plastoquinone electron acceptor of PSII
- QB
second plastoquinone acceptor of PS II 相似文献
78.
Laurel R. Yohe Paúl M. Velazco Danny Rojas Beth E. Gerstner Nancy B. Simmons Liliana M. Dávalos 《Biology letters》2015,11(11)
The earliest record of plant visiting in bats dates to the Middle Miocene of La Venta, the world''s most diverse tropical palaeocommunity. Palynephyllum antimaster is known from molars that indicate nectarivory. Skull length, an important indicator of key traits such as body size, bite force and trophic specialization, remains unknown. We developed Bayesian models to infer skull length based on dental measurements. These models account for variation within and between species, variation between clades, and phylogenetic error structure. Models relating skull length to trophic level for nectarivorous bats were then used to infer the diet of the fossil. The skull length estimate for Palynephyllum places it among the larger lonchophylline bats. The inferred diet suggests Palynephyllum fed on nectar and insects, similar to its living relatives. Omnivory has persisted since the mid-Miocene. This is the first study to corroborate with fossil data that highly specialized nectarivory in bats requires an omnivorous transition. 相似文献
79.
Qihong Zou Bin-Ke Yuan Hong Gu Dongqiang Liu Danny J. J. Wang Jia-Hong Gao Yihong Yang Yu-Feng Zang 《PloS one》2015,10(3)
Resting-state fMRI studies have increasingly focused on multi-contrast techniques, such as BOLD and ASL imaging. However, these techniques may reveal different aspects of brain activity (e.g., static vs. dynamic), and little is known about the similarity or disparity of these techniques in detecting resting-state brain activity. It is therefore important to assess the static and dynamic characteristics of these fMRI techniques to guide future applications. Here we acquired fMRI data while subjects were in eyes-closed (EC) and eyes-open (EO) states, using both ASL and BOLD techniques, at two research centers (NIDA and HNU). Static brain activity was calculated as voxel-wise mean cerebral blood flow (CBF) using ASL, i.e., CBF-mean, while dynamic activity was measured by the amplitude of low frequency fluctuations (ALFF) of BOLD, i.e., BOLD-ALFF, at both NIDA and HNU, and CBF, i.e., CBF-ALFF, at NIDA. We showed that mean CBF was lower under EC than EO in the primary visual cortex, while BOLD-ALFF was higher under EC in the primary somatosensory cortices extending to the primary auditory cortices and lower in the lateral occipital area. Interestingly, mean CBF and BOLD-ALFF results overlapped at the visual cortex to a very small degree. Importantly, these findings were largely replicated by the HNU dataset. State differences found by CBF-ALFF were located in the primary auditory cortices, which were generally a subset of BOLD-ALFF and showed no spatial overlap with CBF-mean. In conclusion, static brain activity measured by mean CBF and dynamic brain activity measured by BOLD- and CBF-ALFF may reflect different aspects of resting-state brain activity and a combination of ASL and BOLD may provide complementary information on the biophysical and physiological processes of the brain. 相似文献
80.
Sara A. DiVall Danny Herrera Bonnie Sklar Sheng Wu Fredric Wondisford Sally Radovick Andrew Wolfe 《PloS one》2015,10(3)
Infertility associated with obesity is characterized by abnormal hormone release from reproductive tissues in the hypothalamus, pituitary, and ovary. These tissues maintain insulin sensitivity upon peripheral insulin resistance. Insulin receptor signaling may play a role in the dysregulation of gonadotropin-releasing hormone (GnRH) secretion in obesity, but the interdependence of hormone secretion in the reproductive axis and the multi-hormone and tissue dysfunction in obesity hinders investigations of putative contributing factors to the disrupted GnRH secretion. To determine the role of GnRH insulin receptor signaling in the dysregulation of GnRH secretion in obesity, we created murine models of diet-induced obesity (DIO) with and without intact insulin signaling in the GnRH neuron. Obese control female mice were infertile with higher luteinizing hormone levels and higher GnRH pulse amplitude and total pulsatile secretion compared to lean control mice. In contrast, DIO mice with a GnRH specific knockout of insulin receptor had improved fertility, luteinizing hormone levels approaching lean mice, and GnRH pulse amplitude and total secretion similar to lean mice. Pituitary responsiveness was similar between genotypes. These results suggest that in the obese state, insulin receptor signaling in GnRH neurons increases GnRH pulsatile secretion and consequent LH secretion, contributing to reproductive dysfunction. 相似文献