全文获取类型
收费全文 | 81篇 |
免费 | 25篇 |
专业分类
林业 | 2篇 |
综合类 | 6篇 |
水产渔业 | 1篇 |
畜牧兽医 | 96篇 |
园艺 | 1篇 |
出版年
2023年 | 4篇 |
2020年 | 4篇 |
2019年 | 2篇 |
2018年 | 7篇 |
2017年 | 8篇 |
2016年 | 7篇 |
2015年 | 4篇 |
2014年 | 7篇 |
2013年 | 5篇 |
2012年 | 4篇 |
2010年 | 1篇 |
2009年 | 5篇 |
2008年 | 2篇 |
2007年 | 2篇 |
2006年 | 1篇 |
2004年 | 2篇 |
2003年 | 6篇 |
2002年 | 2篇 |
2001年 | 4篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 1篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1988年 | 2篇 |
1984年 | 1篇 |
1969年 | 1篇 |
1936年 | 1篇 |
1932年 | 1篇 |
1931年 | 1篇 |
1916年 | 1篇 |
排序方式: 共有106条查询结果,搜索用时 15 毫秒
71.
KATHARINA U. HEDIGER DVM STEPHEN J. FERGUSON DVM PhD PHILIPPE GEDET Dipl. Ing. RE BUSATO DVM MSc PD FRANCK FORTERRE DVM Diplomate ECVS SAMUEL ISLER DVM RETO BARMETTLER DVM JOHANN LANG DVM Diplomate ECVDI 《Veterinary surgery : VS》2009,38(7):874-880
Objective— To determine stiffness and load–displacement curves as a biomechanical response to applied torsion and shear forces in cadaveric canine lumbar and lumbosacral specimens.
Study Design— Biomechanical study.
Animals— Caudal lumbar and lumbosacral functional spine units (FSU) of nonchondrodystrophic large-breed dogs (n=31) with radiographically normal spines.
Methods— FSU from dogs without musculoskeletal disease were tested in torsion in a custom-built spine loading simulator with 6 degrees of freedom, which uses orthogonally mounted electric motors to apply pure axial rotation. For shear tests, specimens were mounted to a custom-made shear-testing device, driven by a servo hydraulic testing machine. Load–displacement curves were recorded for torsion and shear.
Results— Left and right torsion stiffness was not different within each FSU level; however, torsional stiffness of L7-S1 was significantly smaller compared with lumbar FSU (L4-5–L6-7).
Ventral/dorsal stiffness was significantly different from lateral stiffness within an individual FSU level for L5-6, L6-7, and L7-S1 but not for L4-5. When the data from 4 tested shear directions from the same specimen were pooled, level L5-6 was significantly stiffer than L7-S1.
Conclusions— Increased range of motion of the lumbosacral joint is reflected by an overall decreased shear and rotational stiffness at the lumbosacral FSU.
Clinical Relevance— Data from dogs with disc degeneration have to be collected, analyzed, and compared with results from our chondrodystrophic large-breed dogs with radiographically normal spines. 相似文献
Study Design— Biomechanical study.
Animals— Caudal lumbar and lumbosacral functional spine units (FSU) of nonchondrodystrophic large-breed dogs (n=31) with radiographically normal spines.
Methods— FSU from dogs without musculoskeletal disease were tested in torsion in a custom-built spine loading simulator with 6 degrees of freedom, which uses orthogonally mounted electric motors to apply pure axial rotation. For shear tests, specimens were mounted to a custom-made shear-testing device, driven by a servo hydraulic testing machine. Load–displacement curves were recorded for torsion and shear.
Results— Left and right torsion stiffness was not different within each FSU level; however, torsional stiffness of L7-S1 was significantly smaller compared with lumbar FSU (L4-5–L6-7).
Ventral/dorsal stiffness was significantly different from lateral stiffness within an individual FSU level for L5-6, L6-7, and L7-S1 but not for L4-5. When the data from 4 tested shear directions from the same specimen were pooled, level L5-6 was significantly stiffer than L7-S1.
Conclusions— Increased range of motion of the lumbosacral joint is reflected by an overall decreased shear and rotational stiffness at the lumbosacral FSU.
Clinical Relevance— Data from dogs with disc degeneration have to be collected, analyzed, and compared with results from our chondrodystrophic large-breed dogs with radiographically normal spines. 相似文献
72.
73.
74.
75.
GM Alvarez EL Ferretti C Gutnisky GC Dalvit PD Cetica 《Reproduction in domestic animals》2013,48(4):545-553
Glycolytic and pentose phosphate pathway (PPP) activities were modulated in porcine cumulus–oocyte complexes (COCs) during in vitro maturation (IVM) by the addition of inhibitors or stimulators of key enzymes of the pathways to elucidate their relative participation in oocyte maturation. The activities of glycolysis and PPP were evaluated by lactate production per COC and by the brilliant cresyl blue test, respectively. Glucose uptake per COC and the oocyte maturation rate were also evaluated. Lactate production, glucose uptake and the percentage of oocytes reaching metaphase II decreased in a dose‐dependent manner in the presence of the pharmacological (NaF) or the physiological (ATP) inhibitors of glycolysis (p < 0.05). The addition of the physiological stimulator of glycolysis (AMP) caused no effect on lactate production, glucose uptake or the meiotic maturation rate. The pharmacological (6‐AN) and the physiological (NADPH) inhibitors of PPP induced a dose‐dependent decrease in the percentage of oocytes with high PPP activity and in the nuclear maturation rate (p < 0.05). The physiological stimulator of PPP (NADP) caused no effect on the percentage of oocytes with high PPP activity. The glycolytic and PPP activities of porcine COCs and maturational competence of oocytes seem to be closely related events. This study shows for the first time the regulatory effect of ATP and NADPH as physiological inhibitors of glycolysis and PPP in porcine COCs, respectively. Besides, these pathways seem to reach their maximum activities in porcine COCs during IVM because no further increases were achieved by the presence of AMP or NADP. 相似文献
76.
SUMMARY Over a 5-year period (1988–92), von Willebrand factor antigen (vWf:Ag) concentrations were determined on plasma samples from 614 Dobermanns. The vWf:Ag concentration was < 50 canine units (CU)/dL in 373 dogs (61%); these dogs were classified as carriers of the von Willebrand's disease (vWD) gene. In order to identify which dogs were at risk of haemorrhage due to vWD, we determined a cut-off vWf:Ag concentration below which dogs could be considered at risk. This cut-off was chosen in order to minimise the number of dogs genuinely at risk of haemorrhage, being wrongly classified as not at risk. This was done without sacrificing the specificity of the cut-off to any great extent. A vWf:Ag concentration of < 36 CU/dL was empirically chosen as the optimum cut-off concentration. In 282 dogs (76% of the carriers), the vWf:Ag concentration was below this cut-off and these dogs were, thus, classified as being at risk of haemorrhage due to vWD. Haemorrhage attributable to vWD was seen in 107 dogs (29% of the carriers, or 17% of all the dogs). Haemorrhage mostly followed trauma or surgery, but spontaneous genitourinary and gastrointestinal haemorrhages were also frequent. Of these dogs, 92 were of known age, with a median of 3 years, and 102 were of known sex, with 61% being female. In 89 dogs in which the severity of haemorrhage was subjectively assessed, mild and moderate bleeding occurred with similar frequency (48% and 43%, respectively). There were 8 cases of severe haemorrhage, with two deaths. The likelihood of haemorrhage was related to the vWf:Ag concentration: only 8% of 91 dogs with concentrations between 36 and 49 CU/dL had haemorrhage attributable to vWD, but 36% with concentrations < 36 CU/dL did so. Furthermore, dogs with haemorrhage attributable to vWD had significantly (P < 0.001) lower vWf:Ag concentrations (median 12 CU/dL, n = 107) than dogs with no such history (median 30 CU/dL, n = 132). The data indicate that vWD is a significant problem in the Dobermann breed in Australia and we accordingly recommend that steps be taken to reduce its prevalence, such as the establishment of a national testing scheme to determine the vWD status of all dogs used for breeding. 相似文献
77.
78.
K. Fleming MSc E.F. Hessel PD Dr H.F.A. Van den Weghe Prof Dr Ir 《Journal of Equine Veterinary Science》2008,28(7):408-418
Among other factors (eg, feed), bedding material has an important effect on stable air quality with respect to airborne particle formation. This study was designed to establish which material is suited to create an improved stable environment for horses. First, the following materials were analyzed under standardized conditions in a laboratory experiment: wheat straw, dry wood shavings, hemp shives, linen shives, wheat straw pellets, paper cuttings (unprinted newspaper). The second investigation was carried out under in situ conditions in which three of these bedding materials (wheat straw, wood shavings, and straw pellets) were analyzed under practical conditions. In both experiments, airborne particle concentrations were detected online with the gravimetrically measuring analyzer TEOM 1400a (Rupprecht & Patashnick Co., Franklin, MA). In the laboratory experiment, the TEOM was equipped successively with different inlets to measure the particle fractions PM1, PM2.5, PM10, and PM20. During the in situ experiment, only the fraction PM10 was detected. In the laboratory experiment, hemp and linen had the highest generation of airborne particles in all fractions. The lowest particle generation was detected with straw pellets. Results of the in situ investigation supported results of the laboratory experiment with respect to mean particle generation of straw pellets. With an average of 111.2 ± 149.2 μg/m3, it was significantly lower than the mean particle generation of wheat straw with 227.5 ± 280.8 μg/m3. The particle generation of wood shavings had an average of 140.9 ± 141.9 μg/m3 and also was significantly lower than the generation by wheat straw. An activity-correlated variation of particle concentrations was found. In conclusion, taking both experiments into consideration, straw pellets seemed to be suitable for horse stables, to promote an improvement in the stable climate in relation to airborne particle formation. 相似文献
79.
80.