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41.
Sperm DNA integrity is a fundamental prerequisite in fertilization and embryo development. Among DNA integrity tests, the Comet assay is an accurate and sensitive test for the detection of sperm oxidative damage. The aim of this work was to evaluate sperm oxidative damage using the Comet assay and to study the correlation between Comet and routine assays for the evaluation of semen quality. Dogs were divided in two groups: group A (n = 6), comprising dogs with abnormal spermiogram, that is astheno‐, terato‐ or oligoasthenoteratozoospermic (OAT); and group B (n = 8), comprising normospermic dogs. The distribution of sperm oxidative damage was significantly different between the two groups (= .001): group A—median: 31.55%, interquartile range (IQR): 30.18–38.01; group B—median: 0.90%, IQR: 0.65–1.96. The correlation between oxidative damage and abnormal morphology was high (= .846; < .001). There was a negative correlation between progressive motility and oxidative damage (= ?.792; = .001). Basal and oxidative DNA damage of spermatozoa are increased in dogs with non‐normospermic semen. In conclusion, and considering the elevated correlation with classical tests of sperm quality, the Comet assay has ample potential for clinical and research purposes in dogs.  相似文献   
42.
实验利用透射电镜技术和扫描电镜技术对冷冻/解冻后的塔里木马鹿精子的超微结构进行了观察。结果表明:电镜下观察,塔里木马鹿精子头部呈扁平的卵圆形,长约5.95μm。颈部很短且不明显,长约0.45μm,宽为0.62μm。尾部中段横切面近圆形,直径约为0.58μm,轴丝为9×2+2型;线粒体鞘螺旋段为64~70转。尾部末段仅见质膜包围,9束微管和1对中央微管,形成9+2微管结构。冷冻/解冻后塔里木马鹿部分精子结构发生了变化,一些精子肿胀、质膜皱褶、扭曲,部分质膜损坏或溃散;顶体轻度肿胀,顶体外膜凸凹不平,形成突起。冷冻对头部破坏程度较小。  相似文献   
43.
用猪冷冻精子进行体外受精和单精子胞浆内注射(ICSI),并研究添加L-半胱氨酸及不同成熟培养法对猪ICSI胚胎发育的影响。结果表明:用猪冷冻精子生产的ICSI胚胎卵裂率及囊胚发育率分别为68.3%和11.4%,均低于用冷冻精子进行体外受精(IVF)所获得的卵裂率和囊胚发育率(分别为76.9%和19.2%,P<0.05)。在培养液中添加1.71mmol·L~(-1) L-半胱氨酸培养3 h,无论是卵裂率、桑椹胚发育率,还是囊胚发育率,均未得到明显改善(P>0.05);采用含0.4%BSA的NCSU-23培养液进行猪卵母细胞成熟培养,ICSI胚胎卵裂率虽明显高,但各组所获胚胎发育率均无显著差异(P>0.05),表明所用卵母细胞的成熟方法并未对ICSI胚胎发育产生明显的影响;用颗粒细胞或卵丘细胞共培养ICSI胚胎后,卵裂率有明显提高(P<0.05),但各组囊胚发育率无统计学差异。  相似文献   
44.
性别控制技术在家畜育种中的应用   总被引:2,自引:2,他引:0  
家畜性别控制是当今生物学领域的重大研究课题之一。近年来,性别控制技术的研究取得了可喜的进展。作者综述了国内外家畜性别控制的生物学机制、途径、方法及存在的问题和发展前景,为性别控制技术在家畜实际生产中的广泛应用提供理论基础。  相似文献   
45.
Spermatozoa are unique cells because of their morphological and physiological characteristics. They are produced during the process called spermatogenesis. Spermatogenesis consists of three phases: spermatocytogenesis, spermiogenesis and spermiation, during which spermatozoa undergo several changes. Spermatogenesis takes place within the seminiferous tubules containing two types of cells—the germ cells and the Sertoli cells—that alongside the Leydig cells, which play an important role when it comes to normal fertility. Everything is regulated by the hypothalamic–pituitary–gonadal axis and specific hormones due to multi-hormonal feedback systems. Spermatozoa possess morphological and physiological features, which are sometimes completely different from what is observed in various somatic cells. What is more, canine spermatozoa have specific characteristics making them special compared to the spermatozoa of other mammalian species. The metabolic energy production, which is crucial for the appropriate functioning of spermatozoa, can be fuelled by different metabolic pathways utilizing different chemical substrates. Inseparable from the oxidative phosphorylation process is the production of reactive oxygen species, which are both essential and toxic to spermatozoa. Furthermore, epididymis is a very important structure, responsible for the transport and maturation of spermatozoa, which are then stored in the last segment of epididymis—the epididymal cauda. Moreover, the retrieval of spermatozoa from the epididymides is crucial for the development of assisted reproduction techniques and sperm cryopreservation methods. The information gained from the research on domestic dogs might be transferred to their wild relatives, especially those species categorized as endangered.  相似文献   
46.
This study investigated the effect of pentoxifylline (PTX) and Basal Medium Eagle (BME) on frozen–thawed goat spermatozoa. Immediately after initial examination of ejaculated semen, samples were pooled and reexamined for quality. Then, samples were divided into eight equal aliquots and diluted with a basic tris-extender containing PTX (3, 6, 9 mM) and BME (5 mM) to reach a final concentration of 25 × 109 and frozen. After 24 hr, the samples were individually thawed at 37°C for 30 s and evaluated for different characteristics. Obtained post-thaw results from Computer-Assisted Sperm Analysis indicate using of 3 and 6 mM PTX led significantly to an improvement in total motility, progressive motility and velocity characteristics of spermatozoa, except the beat/cross frequency (BCF) which indicated statistically no differences (p > .05) among control and treatments. Diluents prepared with BME (5 mM) and PTX alone (3 and 6 mM) improved significantly the membrane integrity–functionality, acrosome integrity and also hyaluronidase activity. Regarding recovery rate, the results showed significantly (p < .05) higher values for diluents containing 3 and 6 mM PTX compared to other groups. Malondialdehyde concentration exhibited also a significant difference (p < .05) in diluents supplemented with 5 mM BME, 3, 6 and 9 mM PTX, and mixture of 3 mM PTX and 5 mM BME which illustrate a similarity for active mitochondria, apoptotic-like and dead spermatozoa. Finally, the ratio of sperm chromatin dispersion stained spermatozoa presented significant differences (p < .05) among treatments in which the diluents added PTX alone demonstrated significantly lower values than control and extenders containing the mixtures of BME and PTX. In conclusion, the observation in this study indicates using of 3 and 6 mM PTX and BME alone may improve significantly (p < .05) the quality of cryopreserved goat spermatozoa.  相似文献   
47.
Although useful spermatozoa cryopreservation techniques have been established, long-term equilibration seems to be required before freezing the spermatozoa of many species, including dogs. The fertility of cryopreserved dog spermatozoa from five males for a reduced equilibration period (0, 30, 60, 120 and 180 min) in a skim milk (SM)-based extender containing raffinose was evaluated in the present study. When the sperm was diluted with the extender at room temperature (RT) and cryopreserved without equilibration, the proportion of total motile spermatozoa (TMS) after thawing was lower (27%) than when the sperm was equilibrated for 30 min (33%), 60 min (32%), 120 min (44%; p < .05) or 180 min (29%). The proportion of TMS increased as the equilibration time increased and peaked at 120 min. Acrosome integrity was significantly lower in the cryopreserved spermatozoa that had not undergone the initial equilibration than in the equilibrated spermatozoa (p < .05). The normal rate of acrosomes increased with the extension of the first equilibration and peaked at 120 min. When frozen–thawed spermatozoa that had been diluted at RT and subjected to an initial equilibration lasting 60 or 180 min were transcervically inseminated into recipients, there were no differences in the delivery rate, litter size or breeding efficiency. In the cryopreservation of canine spermatozoa using a SM-based extender, even if the initial equilibration time was shortened to 60 min, the results were comparable to those obtained when the conventional method (with an initial equilibration time of 180 min) was used.  相似文献   
48.
The aim of this study was to analyse the reproductive aspects of male bats of three common species of the Phyllostomidae family: Artibeus lituratus, Platyrrhinus lineatus and Sturnira lilium, during dry and rainy months in a specific area of the Cerrado biome. Body weight was significantly higher during the dry months for S. lilium. The gonadosomatic index (GSI) and testicular weight were not significantly different between dry and rainy periods. The tubular parameters were significantly bigger in A. lituratus than in the other two species during both periods. No difference in the tubular/interstitial ratio was observed in any of the species during both periods. In both periods, all sperm cells and germ cell developmental stages were visible on seminiferous tubules whereas sperm cells were observed in epididymides of all sampled animals. The percentage of morphologically normal sperm was low (35%–60%), with no difference between periods. Spermatozoa from A. lituratus presented a leaf-shaped head, while the head was round-shaped in the other two species. In conclusion, our data suggest that males from the three studied species did not present reproductive latency during the most critical weather periods (dry and rainy months) in the metropolitan region of Brasilia, Brazil.  相似文献   
49.
中华乌塘鳢精子的生物学特性及其超低温保存   总被引:19,自引:1,他引:18  
江世贵 《水产学报》2000,24(2):119-122
对中华乌塘鳢精子激活的生理生态学进行了研究,探讨了中华乌塘鳢精子超低温保存方法,中华乌塘鳢精子激活的适宜盐度为5-15;其精子的激活不仅与激活溶溶盐度有关,而且与激活溶液的离子成份有关,激活溶液中K^+的存在一定程度上对精子的活动有抑帛和;中华乌塘鳢精子对PH的适应性强,在PH5.5-9.5范围内,激活率均在709%以上,尤以中性及弱酸性条件下的激活率最高,在PH6.0时精子活力最好。使用筛选出的  相似文献   
50.
黑龙江茴鱼(Thymallus arcticus grubei Dybowski)精子活力的观察   总被引:5,自引:2,他引:3  
用BSS和水两种激活剂对黑龙江茴鱼精子活力进行测定,并在4℃和14℃(室温)条件下,对精原液和用ASP稀释的精液分别进行保存试验.试验结果显示,用BSS和水均可激活黑龙江茴鱼精子,其精子活率分别可达100%和98%.14℃条件下,用BSS激活黑龙江茴鱼精子平均寿命为72.1s,A级(快速)运动时间平均为14.1s;用水激活精子平均寿命为67.2s,A级运动时间平均为12.5s.不同温度保存的精子寿命和快速运动时间也有显著差异:精原液4℃保存2h后精子失去A级运动,其激活率在70%以上,保存6h后激活率小于20%;精原液14℃保存1.5h后精子失去A级运动,其激活率大于70%,4h后激活率小于20%.经ASP(pH分别为7.0、7.8、8.0、8.5、9.0)稀释的精液,在4℃和14℃条件下,BSS和water对精子的激活率均小于20%,且精子均呈现C、D级运动,1.5h后各保存组激活率为0.试验结果表明,BSS对黑龙江茴鱼的精子有良好的激活效果;精原液4℃保存效果好于14℃,在4℃保存条件下2h以内使用,可以得到理想的结果;精液不宜用ASP稀释保存.  相似文献   
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