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51.
1. This study provides evidence that a heliophilic butterfly, the Glanville fritillary (Melitaea cinxia) has adapted differently to environmental variation across latitudes and elevations. 2. In cool air, basking M. cinxia orient themselves perpendicular to the sun's rays to gain heat and take off. During flight, solar heating is reduced because orientation perpendicular to the sun is no longer possible and convective cooling occurs. Consequently, M. cinxia have been shown to suffer net heat loss in flight, even in full sunshine. When flight duration is restricted in this way, the takeoff temperature becomes an important thermal adaptation. 3. Using a thermal imaging camera, takeoff temperatures were measured in experimental butterflies. Butterflies from the northern range limit in Finland took flight at slightly hotter temperatures than butterflies from the southern limit in Spain, and much hotter than butterflies from the elevational limit (1900–2300 m) in the French Alps. Butterflies from low‐elevation populations in southern France also took off much hotter than did the nearby Alpine population. 4. These results suggest that the influence of elevation is different from that of latitude in more respects than ambient temperature. Values of solar irradiance in the butterflies' flight season in each region show that insects from the coolest habitats, Finland and the Alps, experienced similar solar irradiance during basking, but that Finns experienced much lower irradiance in flight. This difference may have favored Finnish butterflies evolving higher takeoff temperatures than Alpine butterflies that also flew in cool air but benefited from more intense radiant energy after takeoff. 相似文献
52.
Melvin L. Myers Henry P. Cole Gregory A. Ibendahl Walter B. Stephens Susan C. Westneat 《人类与生态风险评估》2013,19(4):959-971
Tractors are used in pond culture of catfish for a variety of mobile tasks, including placing aerators into ponds, mowing, spreading feed into ponds, and transporting equipment (e.g., seining reels), as well as for the stationary task of using the tractor's power-take-offs to operate aerators in the ponds. The mobile tasks place the tractor operator at risk of injury in the event of an overturn, and rollover protective structures (ROPS) are a proven intervention to mitigate injury in a tractor overturn. A 2008 survey was conducted among 96 participants in Mississippi (USA) to determine the hours of tractor use for these tasks. This article reports on exposures to tractor-related tasks conducted on catfish farms as identified in this survey. Annual exposure to potential tractor overturns was calculated based on the hours of mobile operation. The overall annual exposure to potential tractor overturns on the catfish farms participating in the survey was 7322 h per farm and 837 h per tractor on these farms. Findings show a prevalence of 88.2% of ROPS-equipped tractors on farms surveyed and a seasonal variation in exposure to each of the tasks, culminating in an annual estimate of exposure by task. 相似文献
53.
Oxidative stress initiates, accompanies and contributes to the development of several human diseases and injuries, including ocular diseases. Reactive oxygen species (ROS) can generate oxidative stress via excessive ROS production and/or decreased physiologically occurring antioxidants. To replace these weakened antioxidants, substances with effective antioxidant properties are needed in order to suppress oxidative stress and enable healing. Molecular hydrogen (H2) is very suitable for this purpose due to its unique properties. H2 is the only antioxidant that crosses the blood–brain and blood-ocular barriers. It quickly penetrates through tissue due to its small molecular size and effectively removes ROS, mainly hydroxyl radicals and peroxynitrite. Apart from its antioxidant effects, H2 also displays anti-inflammatory, antiapoptotic, cytoprotective and mitohormetic properties. A significant advantage of H2 is its nontoxicity, even when applied at high concentrations. In this review, we present the results of studies utilising H2 in the treatment of ocular diseases involving oxidative stress. These results, obtained in experimental animals as well as in human clinical studies, show that the suppression of oxidative stress by H2 treatment leads to the prevention or improvement of ocular diseases. In severe degenerative diseases, H2 slows disease progression. 相似文献
54.
目的:总结儿童胸腔内巨大肿瘤的临床特点与外科治疗方式。方法:回顾性分析12例儿童胸腔内巨大肿瘤患儿的临床、病理学资料,外科处理过程,并对治疗效果进行随访。结果:4例前纵隔肿瘤中2例为梭形细胞瘤,另2例来源于胸腺,分别为良性畸胎瘤和恶性神经鞘瘤,肿瘤均被完整切除;5例后纵隔肿瘤均作肿块切除,最终病理结果4例为神经母细胞瘤,1例为神经节细胞瘤;2例术前诊断为肺肿瘤的患者中,1例作了右全肺切除,1例作右肺中下叶切除,病理报告均为胸膜肺母细胞瘤;1例术前诊断为胸腔内巨大肿块患儿行肿块切除后病理报告为间叶性软骨肉瘤。结论:手术指征、手术径路的把握及术后管理决定了胸腔内巨大肿瘤患儿的治疗效果。 相似文献
55.
Eguchi M Miyazaki T Masatsuji-Kato E Tsuzuki T Oribe T Miwa N 《Molecular and cellular biochemistry》2003,252(1-2):17-23
To search a regimen for prevention of post-ischemic reperfusional (I/R) injuries, I/R in the liver was induced by 30-min clamping and subsequent unfastening of the portal vein of a rat, which underwent previous intravenous administration with ascorbic acid (Asc) of 1 mg/kg or the autooxidation-resistant pro-vitamin C, 2-O-alpha-D-glucosylated Asc (Asc2G) or 2-O-phosphorylated Asc (Asc2P) of 1 mg Asc equivalent/kg from the viewpoint of utilization of antioxidants that can promptly scavenge I/R-derived reactive oxygen species. The administration with Asc, Asc2P or Asc2G prevented some features of hepatic I/R injuries such as release of hepatic marker enzymes GOT and GPT into the blood vessel, cellular degenerative symptoms including vacuolation and cell fragmentation, and nuclear DNA strand cleavage as detected by TUNEL staining. The preventive effects on I/R injuries were in the order: Asc2G > Asc2P >> Asc. This order of preventive degrees of three anti-oxidants is partly attributable to proper efficiency of conversion to vitamin C and stability in blood stream; Asc2P was moderately converted to a free monoanion form of Asc in human serum, but, in rat serum, so efficiently converted to Asc as to undergo the resultant oxidative decomposition before reaching the liver, whereas Asc2G underwent scarce conversion to Asc in human serum but moderate conversion in rat serum, suggesting that Asc2P might be less cytoprotective against I/R injury than Asc2G in the rat liver in a way different from the human liver. In contrast Asc was so susceptible to autooxidation as to be rapidly decomposed in either rat or human serum. The concentrations of ascorbyl radicals (AscR) in serum were unchanged during I/R for sham-operated rats, but appreciably diminished time-dependently for I/R-operated rats as shown by ESR spectra. A marked increase in serum AscR occurred in rats receiving Asc, Asc2G or Asc2P, but it was time-dependently restored down to the pre-ischemic level of AscR in I/R-operated rats more rapidly than in sham-operated rats. Thus, hepatic I/R injuries were shown to be prevented more markedly by Asc2G or Asc2P than by Asc, which is attributable to efficiencies of both vitamin C conversion and subsequent AscR retention. 相似文献
56.
57.
Actinomycosis in fine needle aspiration cytology 总被引:2,自引:0,他引:2
D. K. DAS 《Cytopathology》1994,5(4):243-250
Four cases of actinomycosis were diagnosed by fine needle aspiration (FNA) cytology and eight more cases were detected during a review of FNA smears reported as inflammatory. the age of these 12 cases ranged from 20 to 61 years with a median of 35 years. the male to female ratio was 3:1. the common regions of involvement were cervicofacial in seven cases (58.3%), thoracic in three (25.0%) and abdominal in two (16.7%). Four of the seven cervicofacial cases presented with intra-oral masses; the thoracic lesions were pulmonary in location, and the abdominal lesions presented as bowel masses. the possibility of actinomycosis was not considered clinically in any case. the main reason for missed cytodiagnosis in two thirds of the cases appeared to be observer error. It is suggested that when the aspiration smear from a mass is found to be an inflammatory exudate rich in neutrophils, special efforts must be made to look for this microorganism. 相似文献
58.
John HA Laffling AJ Marrs J Baird A Jat PS Holdstock NB Rossdale PD 《Cell biology and toxicology》2000,16(1):63-74
To enable direct testing of a range of potential toxins or pathogens that might be involved in grass sickness, equine thoracic
sympathetic chain ganglion cell lines were established from primary cell cultures by retroviral-mediated transduction of the
temperature-sensitive mutant of the establishment oncogene encoding SV40 large T antigen. Morphological and behavioral features,
temperature dependence, and immunocytochemical characteristics of the cell lines were investigated. The majority of cells
were noradrenergic neurons in which dopamine-β-hydroxylase, the enzyme that catalyzes norepinephrine synthesis, and neuropeptide
Y coexisted.
Cells treated with plasma from grass sickness cases that had previously been shown to induce autonomic nervous system damage
when injected into normal horses showed significantly decreased mitochondrial function after 1 day. After 3 days exposure
most cells showed severe degeneration in contrast to those treated with normal plasma. Liver and lung cell lines were also
susceptible to plasma, suggesting that the toxin is not specifically neurotoxic.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
59.
Abstract. 1. Most lepidopteran larvae use all of their legs (thoracic legs and abdominal prolegs) when walking on solid substrates. When caterpillars involuntarily or intentionally drop from the tree canopy, they can regain their original position by climbing silk lifelines spun out from the head spinnerets. However, the taxonomic distribution of this climbing behaviour in the Lepidoptera is unknown.
2. Here, lifeline-climbing behaviour is reported in 13 lepidopteran species belonging to different taxa (five superfamilies and six families: Zygaenidae, Drepanidae, Geometridae, Lymantriidae, Noctuidae, and Nymphalidae). Caterpillars usually used only the three pairs of thoracic legs to climb lifelines, although they use different methods to walk on solid substrates, according to their taxonomic grouping and number of prolegs.
3. Results suggest that lifeline-climbing behaviour using only the thoracic legs is common among various lepidopteran taxa. The majority of species (12 of 13) climbed lifelines by alternating movement of the left and right set of thoracic legs, aided by side-to-side body movements. Only one of the 13 species, the geometrid Naxa seriaria (Motschulsky), climbed lifelines by drawing them down with its thoracic legs, aided by abdominal looping movements. While side-to-side movement of the abdomen was previously reported in lifeline climbing, this is the first report of the use of looping movements. 相似文献
2. Here, lifeline-climbing behaviour is reported in 13 lepidopteran species belonging to different taxa (five superfamilies and six families: Zygaenidae, Drepanidae, Geometridae, Lymantriidae, Noctuidae, and Nymphalidae). Caterpillars usually used only the three pairs of thoracic legs to climb lifelines, although they use different methods to walk on solid substrates, according to their taxonomic grouping and number of prolegs.
3. Results suggest that lifeline-climbing behaviour using only the thoracic legs is common among various lepidopteran taxa. The majority of species (12 of 13) climbed lifelines by alternating movement of the left and right set of thoracic legs, aided by side-to-side body movements. Only one of the 13 species, the geometrid Naxa seriaria (Motschulsky), climbed lifelines by drawing them down with its thoracic legs, aided by abdominal looping movements. While side-to-side movement of the abdomen was previously reported in lifeline climbing, this is the first report of the use of looping movements. 相似文献
60.
Preliminary study of the effects of caspase inhibitors on vasospasm in dog penetrating arteries 总被引:14,自引:0,他引:14
This preliminary study was undertaken to explore the possible protective effect of caspase inhibitors Z-VDVAD-FMK and Z-DEVD-FMK in apoptosis and vasospasm in penetrating arteries during cerebral vasospasm. Experimental subarachnoid hemorrhage (SAH) was induced in 16 dogs by an intracisternal injection of autologous arterial blood (0.4 ml/kg) on Day 0 and Day 2. The dogs were then randomly divided into four groups: control-SAH, vehicle-control, and two treatment groups. In the treatment groups, caspase inhibitors (10 microM) were intracisternally injected each day beginning on Day 2 until Day 6. Effects of the inhibitors were analyzed utilizing angiography, the clinical status of the dogs (activity, appetite, and neurological deficits), and transmission electron microscopy of the penetrating arteries. All the dogs were sacrificed on Day 7. In control-SAH and vehicle-control groups, severe angiographic vasospasm, poor clinical status, and penetrating vasospasm were registered in all the dogs. In the treatment groups, all the dogs developed angiographic vasospasm and vasospasm in penetrating arteries, however, with benign clinical statues. The occurrence of apoptosis in endothelial cells was reduced by caspase-2 but not by caspase-3 inhibitor. Caspase inhibitors failed to prevent vasospasm either in major or in penetrating arteries. The improvement of clinical scores by the caspase inhibitors may be related to their protection of the endothelial cells. Further investigations using more rigorous clinical scoring system and quantitative information on the degree of apoptosis in the vessels, as well as in the brain parenchyma are recommended. 相似文献