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91.
Bee venom (BV) is a biotoxin with biologically active peptides which have cell lysis and hemolytic activity properties. These properties can be affected under different storage conditions or during the production process. In present study, we investigated effects of a number of physicochemical factors, including temperature, pH, UV radiation, ultrasound waves and storage time on hemolytic activity of BV. Maximum absorption and melting temperature of BV solution were obtained as 280 nm and ~70 °C, respectively. Cell hemolysis 50 (CH50) -concentration of BV that can lyse 50% of red blood cells- was determined as 0.94 μg/ml at ambient temperature. CH50 was shown not to be importantly varied at temperature up to 60 °C, pH value 2 to 13 and under UV/ ultrasound radiation. Storage at ?20, 6 and 25 °C for 6 months made about 2.5, 35 and 1000 times increase in CH50. From the results, it may be concluded that BV is a relatively resistant hemolytic agent and can be used in a variety of laboratory research and product manufacturing methods.  相似文献   
92.
Unlike most praying mantises that have a single region of auditory sensitivity, species in the genus Creobroter have equally sensitive hearing at 2–4 and at 25–50 kHz and and are relatively insensitivity at 10–15 kHz — they have a W-shaped audiogram. Ultrasonic sensitivity originates from an auditory organ in the ventral midline of the metathorax that closely resembles the ear of other mantises. Ablation experiments demonstrate that low frequency sensitivity derives from a serially homologous mesothoracic auditory organ. Extracellular recordings suggest that these two ears operate largely, if not entirely, independently of one another in the thorax. The low frequency response has a longer latency, more action potentials per stimulus, and different patterns of change with increasing SPL than the high frequency response. Separate interneurons mediate responses in the two frequency ranges, but our evidence suggests that they are two serially homologous sets of cells. Neither auditory organ shows any physiological evidence of directional sensitivity. Ultrasound triggers a set of behaviors in flying hymenopodid mantises much like those in other mantises, but the behavioral significance of low frequency hearing in these animals is still unknown.Abbreviations SPL sound pressure level - dB SPL sound pressure level re: 20 Pa - HF high frequency - LF low frequency  相似文献   
93.
Material properties of tissue in vivo present an opportunity for clinical analysis of healing progression and pathologies as well as provide an excellent research tool yielding quantified data for longitudinal and cross population studies. Echogenicity is a material?s ability to reflect sound and, using ultrasound, it has been shown to increase with tendon tension in vitro, though this non-invasive measurement technique for determining mechanical properties has not been tested in vivo. The aim of this study was to establish if echogenicity, seen by the increase in image brightness, could be correlated to stress within a tissue. 18 Achilles tendons were imaged in the sagittal and transverse planes while producing a series of isometric contractions starting from rest and producing the torque equivalent of 0.5, 1.0, 1.5, and 2.0× body weights. Manual tracing identified the tendon in each of the images. The cross-sectional area determined from the transverse plane images in conjunction with the tendon force yielded the tendon stress. The echogenicity of the tendon was determined from the mean brightness change from rest to each of the contraction cases, measured from the sagittal plane images. A weak correlation existed between the echogenicity and stress (R=0.25) but it was found that there was no significant change in axial area during contraction (p=0.683) establishing the tendon as incompressible. Echogenicity proved to be non-functional for measuring the mechanical properties of the Achilles tendon due to the additional factors included with in vivo testing e.g. tendon twist and multi-axial loading.  相似文献   
94.
《Journal of biomechanics》2014,47(16):3813-3819
Acoustoelastic (AE) ultrasound image analysis is a promising non-invasive approach that uses load-dependent echo intensity changes to characterize stiffness of tendinous tissue. The purpose of this study was to investigate whether AE can detect localized changes in tendon stiffness due to partial and full-thickness tendon tears. Ovine infraspinatus tendons with different levels of damage (Intact, 33%, 66% and full thickness cuts initiated on the articular and bursal sides) were cyclically loaded in a mechanical testing system while cine ultrasound images were recorded. The load-induced changes in echo intensity on the bursal and articular side of the tendon were determined. Consistent with AE theory, the undamaged tendons exhibited an increase in echo intensity with tendon loading, reflecting the strain-stiffening behavior of the tissue. In the intact condition, the articular region demonstrated a significantly greater increase in echo intensity during loading than the bursal region. Cuts initiated on the bursal side resulted in a progressive decrease in echo intensity of the adjacent tissue, likely reflecting the reduced load transmission through that region. However, image intensity information was less sensitive for identifying load transmission changes that result from partial thickness cuts initiated on the articular side. We conclude that AE approaches may be useful to quantitatively assess load-dependent changes in tendon stiffness, and that disruption of AE behavior may be indicative of substantial tendon damage.  相似文献   
95.
The development of hemorrhagic anovulatory follicles (HAF) involves luteinization and hemorrhage of the follicle. This is observed on ultrasound as an increase in the echogenicity of the granulosa layer and formation of echoic particles in the antrum. The inhibition of prostaglandin synthesis with flunixin meglumine (FM) during the periovulatory period induces ovulatory failure with development of luteinized unruptured follicles (LUF). These two types of anovulatory follicles appear to share similar ultrasound features but they have not been compared critically. The following endpoints: follicle diameter, follicular contents score, interval from hCG administration to beginning of follicular hemorrhage, interval from hemorrhage to organization of follicular contents, and cycle length were studied and compared in mares with HAF (n = 11) and LUF (n = 13). The objective of this study was to elucidate whether these two unruptured follicles have a consistent clinical pattern of development and therefore can be considered as part of the same anovulatory syndrome. None of the endpoints analyzed differed significantly between HAF and LUF. However, there was a greater individual variation in HAF as compared with LUF in regards to interval from hCG to hemorrhage, follicular diameter at the administration of hCG, and beginning of hemorrhage. In conclusion, HAF share a similar cascade of ultrasound characteristics with the experimentally induced LUF. This finding may provide new insights in elucidating the pathogenesis of HAF.  相似文献   
96.
Parvalbumins beta (β-PRVBs) are considered the major fish allergens. A new strategy for the rapid and direct detection of these allergens in any foodstuff is presented in this work. The proposed methodology is based on the purification of β-PRVBs by treatment with heat, the use of accelerated in-solution trypsin digestion under an ultrasonic field provided by High-Intensity Focused Ultrasound (HIFU) and the monitoring of only nineteen β-PRVB peptide biomarkers by Selected MS/MS Ion Monitoring (SMIM) in a linear ion trap (LIT) mass spectrometer. The present strategy allows the direct detection of the presence of fish β-PRVBs in any food product in less than 2 hours.  相似文献   
97.

Background

The superficial vein of the resting limb constricts sympathetically during exercise. Central command is the one of the neural mechanisms that controls the cardiovascular response to exercise. However, it is not clear whether central command contributes to venous vessel response during exercise. Tendon vibration during static elbow flexion causes primary muscle spindle afferents, such that a lower central command is required to achieve a given force without altering muscle force. The purpose of this study was therefore to investigate whether a reduction in central command during static exercise with tendon vibration influences the superficial venous vessel response in the resting limb.

Methods

Eleven subjects performed static elbow flexion at 35% of maximal voluntary contraction with (EX + VIB) and without (EX) vibration of the biceps brachii tendon. The heart rate, mean arterial pressure, and rating of perceived exertion (RPE) in overall and exercising muscle were measured. The cross-sectional area (CSAvein) and blood velocity of the basilic vein in the resting upper arm were assessed by ultrasound, and blood flow (BFvein) was calculated using both variables.

Results

Muscle tension during exercise was similar between EX and EX + VIB. However, RPEs at EX + VIB were lower than those at EX (P <0.05). Increases in heart rate and mean arterial pressure during exercise at EX + VIB were also lower than those at EX (P <0.05). CSAvein in the resting limb at EX decreased during exercise from baseline (P <0.05), but CSAvein at EX + VIB did not change during exercise. CSAvein during exercise at EX was smaller than that at EX + VIB (P <0.05). However, BFvein did not change during the protocol under either condition. The decreases in circulatory response and RPEs during EX + VIB, despite identical muscle tension, showed that activation of central command was less during EX + VIB than during EX. Abolishment of the decrease in CSAvein during exercise at EX + VIB may thus have been caused by a lower level of central command at EX + VIB rather than EX.

Conclusion

Diminished central command induced by tendon vibration may attenuate the superficial venous vessel response of the resting limb during sustained static arm exercise.  相似文献   
98.
Fetal growth during pregnancy has previously been studied in the domesticated guinea pig (Cavia aperea f. porcellus) after dissecting pregnant females, but there are no studies describing the fetal growth in their wild progenitor, the wild guinea pig (C aperea). In this study, 50 pregnancies of wild guinea pig sows were investigated using modern ultrasound technique. The two most common fetal growth parameters (biparietal diameter [BPD] and crown-rump-length [CRL]) and uterine position were measured. Data revealed similar fetal growth patterns in the wild guinea pig and domesticated guinea pig in the investigated gestation period, although they differ in reproductive milestones such as gestation length (average duration of pregnancy 68 days), average birth weight, and litter mass. In this study, pregnancy lasted on average 60.2 days with a variance of less than a day (0.96 days). The measured fetal growth parameters are strongly correlated with each (R = 0.91; P < 0.001) other and with gestational age (BPD regression equation y = 0.04x − 0.29; P < 0.001 and CRL regression equation y = 0.17x − 2.21; P < 0.01). Furthermore, fetuses in the most frequent uterine positions did not differ in their growth parameters and were not influenced by the mother ID. Our results imply that ultrasound measurement of a single fetal growth parameter is sufficient to reliably estimate gestational age in the wild guinea pig.  相似文献   
99.
For the prevention of excess sludge production from a membrane bioreactor (MBR), an ultrasonic cell disintegration process was incorporated. The results of this study showed that excess sludge production could be prevented using an ultrasound hybrid (MBR-US) system at an organic loading of around 0.91 kg BOD5/m3 per day. Under the same organic loading rate, the mixed liquor suspended solid (MLSS) of MBR-US system was maintained at 7000–8000 mg/l while the MLSS of a conventional MBR increased from 7000 to 13,700 mg/l during the experimental period. While sludge production was completely prevented, the effluent quality of the MBR-US system slightly deteriorated. The additional organic loading caused by disintegrated sludge return was considered to be a reason. With sonication the volume of the average particle size of the sludge in the aeration tank decreased from 132 to 95 μm. In the MBR-US system, around 25–30% of total phosphorus removal was achieved without sludge removal from the aeration tank.  相似文献   
100.
目的:比较超声引导介入治疗盆腔脓肿、输卵管积脓、输卵管积液、包裹性积液及宫颈囊肿的,临床效果,了解超声引导介入治疗常见的妇科囊性炎症包块的临床价值。方法:选取我院妇科门诊2007年1月~2011年3月收治的常见妇科囊性炎症包块共108例,其中盆腔脓肿11例、输卵管积脓19例、输卵管积液43例、盆腔包裹性积液31例、宫颈囊肿4例,给予超声实时引导抽囊液、甲硝唑冲洗治疗,治疗后3个月内复查超声评价和比较疗效。结果:盆腔脓肿、输卵管积脓、盆腔包裹性积液包块均明显缩小(12/43)或消失(29/43),治疗有效率100%;输卵管积液包块治疗有效率95%(41/43),宫颈囊肿均痊愈。各组间比较无统计学差异(P〉O.05)。结论:超声引导介入治疗对输卵管积脓、盆腔脓肿、盆腔包裹性积液均有显著的疗效,且治疗效果无差异,值得推广应用,代替传统的非必要的手术治疗。  相似文献   
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