首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   186篇
  免费   0篇
林业   9篇
农学   9篇
  12篇
综合类   19篇
农作物   2篇
水产渔业   10篇
畜牧兽医   99篇
园艺   1篇
植物保护   25篇
  2013年   2篇
  2011年   6篇
  2010年   7篇
  2009年   8篇
  2008年   4篇
  2006年   1篇
  2005年   2篇
  1998年   3篇
  1997年   11篇
  1996年   5篇
  1995年   10篇
  1994年   6篇
  1993年   6篇
  1992年   10篇
  1991年   8篇
  1990年   10篇
  1989年   2篇
  1988年   6篇
  1987年   2篇
  1986年   9篇
  1985年   7篇
  1984年   4篇
  1983年   2篇
  1982年   1篇
  1981年   4篇
  1980年   2篇
  1979年   2篇
  1978年   1篇
  1977年   2篇
  1976年   2篇
  1975年   3篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1966年   2篇
  1963年   1篇
  1962年   2篇
  1960年   2篇
  1959年   3篇
  1958年   5篇
  1957年   4篇
  1956年   4篇
  1955年   1篇
  1954年   3篇
  1953年   3篇
  1952年   1篇
  1951年   1篇
  1948年   1篇
  1946年   2篇
排序方式: 共有186条查询结果,搜索用时 15 毫秒
81.
Objective— To characterize the behavior of horses recovering in the Anderson Sling Suspension System after 4 hours of desflurane anesthesia and postdesflurane intravenous (IV) administration of propofol and xylazine. Study Design— Experimental study. Animals— Healthy horses (n=6), mean±SEM age 12.3±1.8 years; mean weight 556±27 kg. Methods— Each horse was anesthetized with xylazine, diazepam, and ketamine IV and anesthesia was maintained with desflurane in O2. At the end of 4 hours of desflurane, each horse was positioned in the sling suspension system and administered propofol–xylazine IV. Recovery events were quantitatively and qualitatively assessed. Venous blood was obtained before and after anesthesia for biochemical and propofol analyses. Results— Anesthetic induction and maintenance were without incident. Apnea commonly accompanied propofol administration. All horses had consistent recovery behavior characterized by a smooth, careful, atraumatic return to a standing posture. Conclusions— Results of this study support careful, selective clinical use of desflurane, propofol–xylazine, and the Anderson Sling Suspension System to atraumatically transition horses with high anesthetic recovery risk to a wakeful standing posture. Clinical Relevance— Technique choices to facilitate individualized, atraumatic recovery of horses from general anesthesia are desirable. Use of IV propofol and xylazine to transition horses from desflurane anesthesia during sling recovery to standing posture may facilitate improved recovery management of high‐injury risk equine patients requiring general anesthesia.  相似文献   
82.
Objective — To determine if intra-articular anesthesia of the distal interphalangeal joint could alleviate lameness associated with the navicular bursa in horses.
Study Design — Experimental investigation.
Animals — Six clinically normal horses.
Methods — Lameness was induced in each horse by injecting either the left or right front navicular bursa with 5 mg of amphotericin-B. Forty-eight hours later each horse was videotaped walking and trotting before, and 5, 30, and 60 minutes after injecting the distal interphalangeal joint of the treated limb with 5 mL of 2% mepivacaine hydrochloride. All video recordings were then rerecorded onto master tapes in a random sequence. Four clinicians, unaware of the animal identity related to observation time or limb treated, independently viewed these tapes and graded the lamenesses.
Results — There was a significant reduction in lameness 5 and 30 minutes after anesthetic was injected into the distal interphalangeal joint. Lameness scores 60 minutes after anesthetic administration were not significantly different than baseline values. Gross pathological examination confirmed marked inflammation of the treated navicular bursae and normal appearance of the distal interphalangeal joints.
Conclusions — Intra-articular anesthesia of the distal interphalangeal joint can alleviate lameness associated with the navicular bursa.
Clinical Relevance — Intra-articular anesthesia of the distal interphalangeal joint is not specific only for lameness originating in the distal interphalangeal joint.  相似文献   
83.
Summary. Granulated compound fertilizers were tested as solid carriers for a variety of herbicides known to be active when applied as liquids.
Pasture and cereal experiments with 2,4-D and MCPA as fertilizer additives indicated considerable loss of herbicidal activity in comparison with spray formulations.
Residual herbicides such as TCA, propham and diuron retained their activity when added to fertilizer for application to root crops. The most effective of the herbicides used as fertilizer additives were TCA and propham, both of which gave good control of Avena fatua in sugar beet, and a mixture of chlorpropham and diuron gave promising results as a general weed control treatment in carrots.
It is concluded that the addition of these or similar herbicides to fertilizer granules may have advantages over conventional spray formulations for those crops which require broadcast pre-sowing applications of herbicides and fertilizer. For such crops the use of a granular fertilizer as the carrier instead of inert material could also have advantages over conventional granular herbicides, particularly by reducing transport and application costs.  相似文献   
84.
Pores in soil, especially in cracking clays, interconnect in more or less complex patterns. The complexity of the pattern can be represented by its connectivity. The connectivity of a network of cracks is the number of loops in it, and the number of loops per unit volume of soil is the connectivity density (Gv) .
The patterns of cracks wider than 60 μm were exposed in parallel sections 50 μm apart, photographed and skeletonized. Loops were tracked from one section to another and counted. Other loops completed in three dimensions but not apparent in horizontal sections were recognized and added to the count. The counts were linearly related to the number of sections examined, and by regression analysis stable and precise estimates of Gv were obtained for the clay subsoils of Windsor and Swanwick soil series from as few as eight sections. The connectivity density of the crack pattern in the Windsor subsoil was approximately 300 cm−3 and that of the Swanwick series about 195 cm−3.  相似文献   
85.
86.
87.
88.
A model simulating acute-compressive spinal cord trauma at the second lumbar spinal cord segment (100 g, 300 seconds) was used to evaluate the efficacy of a vehicle control, methylprednisolone sodium succinate (MPSS), and a 21-aminosteroid compound (U74389G). Dogs were allocated into one of five treatment groups (A to E) using ultrasonographic determination of spinal cord diameters to ensure even distribution of spinal cord diameters among the treatment groups. Initial dosages of the vehicle control (A), methylprednisolone (30 mg/kg of body weight) (B), or U74389G (30 mg/kg, 3 mg/kg, or 10 mg/kg of body weight) (C, D, or E, respectively) were administered intravenously 30 minutes after trauma. Dosages were reduced by one-half for 2 and 6 hour treatments. Then every 4 hours for 42 hours, dosages were reduced one-third and one-sixth from the original dose of methylprednisolone and U74389G, respectively. Neurological examinations were performed daily for 21 days. Histopathological examination of the traumatized spinal cord showed malacic and degenerative lesions. Although significant differences in some portions of the neurological and histopathologic examinations were observed, clinical efficacy for MPSS and U74389G could not be established in this model.  相似文献   
89.
Abstract Skin biopsy specimens from 107 dogs with endocrine skin disorders were examined for the presence of melanin granules in the sebaceous glands or ducts (sebaceous gland melanosis). Nineteen of these cases (17.8%) had sebaceous gland melanosis. Skin biopsy specimens from 71 dogs with follicular dysplasia were similarly examined and 27 (38.0%) had sebaceous gland melanosis. Sebaceous gland melanosis alone cannot be used to differentiate histologically follicular dysplasia and endocrine skin disorders. Résumé— Des biopsies cutanées provenant de 107 chiens présentant des troubles cutanés associés à une dysendocrinie ont été examinées pour la rechereche de granules de mélanine dans les glandes sébacées ou dans leurs canaux (mélanose des glandes sébacées). Dix neuf de ces cas (17,8%) présentaient une mélanose des glandes sébacées. Des biopsies provenant de 71 chiens à dysplasic folliculaire ont été examinées de la même manière et 27 (38%) de ces cas présentaient également une mélanose des glandes sébacées. La mélanose des glandes sébacées seule ne peut être utilisée pour différencier histopathologiquement les dysplasies folliculaires des lésions cutanées associées à une dysendocrinie. [Bagladi, M.S., Scott, D.W., Miller, W.H. Sebaceous gland melanosis in dogs with endocrine skin disease or follicular dysplasia: A retrospective study (Mélanose des glandes sébacées chez des chiens présentant une dysendocrinic à expression cutanée et chez des chiens présentant une dysplasie folliculaire). Veterinary Dermatology 1996; 7 : 85–90.] Resumen Se examinó la presencia de gránules de melanina en las glándulas sebáceas (melanosis de glándulas sebáceas) en muestras de biopsia cutánea de 107 perros con desequilibrios endocrinos cutáneos. Diecinueve de estos casos (17.8%) mostraban melanosis de glándulas sebáceas. Las muestras de biopsia cutánea de 71 perros con displasia folicular se examinaron de forma similar y 27 (38.0%) mostraban melanosis de glándulas sebáccas. La melanosis de glándulas sebáceas en sí no puede utilizarse para diferenciar histológicamente entre la displasia folicular y los desequilibrios endocrinos. [Bagladi, M.S., Scott, D.W., Miller, W.H. Sebaceous gland melanosis in dogs with endocrine skin disease or follicular dysplasia: A retrospective study (Melanosis glandulas sebaceas en perros con enfermedad endocrina o dysplasia folicular: estudio retrospectivo). Veterinary Dermatology 1996; 7 : 85–90.] Zusammenfassung— Es wurden Hautbiopsien von 107 Hunden mit endokrinen Hauterkrankungen auf das Vorkommen von Melaningranula in den Talgdrüsen oder -ausführungsgängen (Talgdrüsenmelanose) untersucht. 19 dieser Fälle (17,8%) zeigten Talgdrüsenmelanose. Die Hautbiopsien von 71 Hunden mit follikulärer Dysplasie wurden auf ähnliche Weise untersucht, 27 davon (38,0%) wiesen ebenfalls Talgdrüsenmelanose auf. Talgdrüsenmelanose allein kann nicht dazu verwendet werden, um histologisch follikuläre Dysplasie und endokrine Hauterkrankungen zu unterscheiden. [Bagladi, M. S., Scott, D. W., Miller, W. H. Sebaceous gland melanosis in dogs with endocrine skin disease of follicular dysplasia: a retrospective study (Talgdrüsenmelanose bei Hunden mit endokrinen Hauterkrankungen oder follikulärer Dysplasie: eine retrospektive Studie). Veterinary Dermatology 1996; 7 : 85–90.]  相似文献   
90.
Abstract— In a retrospective postmortem survey of laboratory woodchucks (Marmota monax), four neoplastic and one hyperplastic skin lesions were identified. These included two lipomas and single cases each of squamous cell carcinoma, apocrine gland adenoma and sebaceous gland hyperplasia. Three animals were male, the other two female. Animals ranged from 2 to 7 years of age. Four animals were negative for markers of woodchuck hepatitis virus (WHV). The other, a 7-year-old female with an axillary lipoma, was a chronic carrier. Four neoplasms were discrete masses; the digital squamous cell carcinoma was more extensive, infiltrative and interfered with prehension. The low incidence of skin tumours (0.8 per cent) parallels that described in other laboratory rodent species. Résumé— Une étude rétrospective portant sur des autopsies de marmottes de laboratoire (Marmota monax) a permis la mise en évidence de 4 lésions néoplasiques et d'une lésion hyperplasique de la peau. Il s'agissait de deux lipomes ainsi que de cas isolés d'épthélioma spinocellulaire, d'adénome apocrine et d'hyperplasie sébacée. Trois animaux étaient des mäles et deux, des femelles. L'äge variait de 2 à 7 ans. Quatre animaux étaient négatifs au marqueur de l'hépatite virale de la marmotte (WHV). Le cinquième, une femelle de 7 ans présentant un lipome axillaire, était un porteur chronique. Quatre des néoplasies étaient des masses discrètes; l'épithélioma spinocellulaire du doigt était plus extensif, infiltrant et gênait la préhension. La faible incidence des tumeurs cutanées (0,8%) est identique à celle que l'on décrit chez d'autres rongeurs de laboratoire. Zusammenfassung— In einer retrospektiven postmortalen Untersuchung von Labor-Murmeltieren (Marmota monax) wurden vier neoplastische und eine hyperplastische Hautveränderung festgestellt. Darunter waren zwei Lipome und einzelne Fälle von jeweils einem Plattenepithelkazinom, einem apokrinen Adenom und einer Talgdrüsenhyperplasie. Drei Tiere waren männlich, die beiden anderen weiblich. Das Alter der Tiere lag zwischen 2 und 7 Jahren. Vier der Tiere reagierten negativ auf Murmeltier-Hepatitis-Virus-Marker (WHV). Ein weiteres 7 Jahre altes weibliches Tier mit einem Lipom im Achselbereich war chronischer Träger. Vier der Neubildungen stellten diskrete Massen dar; das Plattenepithelkarzinom im Fußbereich war ausgedehnter, infiltrativ wachsend und beeinträchtigte die Greifbewegungen. Das geringe Vorkommen von Hauttumoren (0,8%) entspricht demjenigen, das bei anderen Nagern beschrieben wurde. Resumen En un estudio retrospectivo postmortem de marmotas de laboratio (Marmota monax) se identificaron cuatro lesiones neoplásicas cutáneas y una lesión cutánea de tipo hiperplásico. Entre estas se encontraban dos lipomas y casos individuales de carcinoma de células escamosas, adenoma de glándulas apocrinas e hiperplasia de glándulas sebáceas. Tres animales eran machos y los dos restantes eran hembras. La edad de los animales oscilaba entre los dos y los siete años. Cuatro animales fueron negativos para maracadores del virus de la hepatitis de la marmota. El otor, una hembra de 7 años de edad con un lipoma axilar, era un portador crónico. Cuatro neoplasias eran masas bien delimitadas mientras que el carcinoma de células escamosas digital era aprehensión. Esta baja incidencia de neoplasias cutánea en la marmota (0,8%) es semejante a la descrita en otros roedores de laboratorio.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号