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101.
SHIDOW TORISU MAKOTO WASHIZU DAISUKE HASEGAWA HIROMITSU ORIMA 《Veterinary radiology & ultrasound》2005,46(6):447-451
Animals with a portosystemic shunt (PSS) often have neurologic abnormalities. Diagnostic imaging, including brain magnetic resonance (MR) imaging, is not performed routinely in these animals. In this study, brain MR images were obtained in 13 dogs and three cats with a PSS, and in 15 dogs and five cats that were neurologically normal and used as controls. All animals with a PSS had widened sulci. In addition, 10 out of 13 dogs with a PSS and one out of three cats with a PSS had hyperintense focal areas in the lentiform nuclei on T1-weighted (T1W) images, which did not enhance after intravenous gadolinium. Following surgical correction of the PSS, MR imaging examinations were repeated in one dog and one cat. The hyperintensity of the lentiform nuclei had decreased. This study indicates that MR imaging findings of widened sulci and hyperintensity of the lentiform nuclei on T1W images may be found in dogs and cats with a PSS. 相似文献
102.
Rachel C. Murray Michael C. Schramme Sue J. Dyson Marion V. Branch Tony S. Blunden 《Veterinary radiology & ultrasound》2006,47(1):1-16
Palmar foot pain is a common cause of lameness. Magnetic resonance imaging (MRI) has the potential to detect damage in all tissues of the equine foot, but an understanding of the differences in magnetic resonance (MR) images between feet from horses with and without palmar foot pain is required. This study aimed to describe MR findings in feet from horses with no history of foot-related lameness, and to compare these with MR findings in horses with lameness improved by palmar digital local analgesia. Thirty-four limbs from horses euthanized with a clinical diagnosis of navicular syndrome (ameness >2 months duration, positive response to palmar digital nerve blocks and absence of other forelimb problems) (Group L), and 25 feet from age-matched horses with no history of foot pain (Group N) were examined. For each anatomic structure, MR signal intensity and homogeneity, size, definition of margins, and relationships with other structures were described. Alterations in MR signal intensity and homogeneity were graded as mild, moderate, or severe and compared between Groups L and N. Results revealed that there were significant differences in MR images between Groups N and L. Multiple moderate-severe MR signal changes were present in 91% of limbs from Group L and moderate (none were graded severe) in 27% of limbs from Group N. In most Group L limbs, more than three structures and frequently six to eight structures were abnormal. Concomitant abnormalities involved most frequently the deep digital flexor tendon, distal sesamoidean impar ligament, navicular bone, collateral sesamoidean ligament, and navicular bursa (with significant associations in severity grade between these structures), sometimes with involvement of the distal interphalangeal joint and/or its collateral ligaments. It was concluded that findings on MR images were different between horses with and without foot pain, and that pain localized to the foot was associated with MR changes in a variety of structures, indicating that damage to several structures may occur concurrently and that MR imaging was useful for evaluation of foot pain. 相似文献
103.
SIMON R. PLATT J. FRASER MCCONNELL MARK BESTBIER 《Veterinary radiology & ultrasound》2006,47(1):78-82
A 4-year-old neutered female terrier-cross was evaluated for an acute onset of paraplegia. Utilizing magnetic resonance (MR) imaging, the cause of the neurologic deficits was determined to be a lumbar intervertebral disc extrusion. The MR study additionally demonstrated parenchymal hyperintensity on T2-weighted images and similarly located diffuse hypointensity on gradient echo images, cranial and caudal to the compressive extradural lesion. Hemorrhagic myelomalacia was suspected based on these MR characteristics, which was subsequently confirmed surgically and histopathologically. 相似文献
104.
FERDINAND VON PRAUN KASPAR MATIASEK VERA GREVEL MICHAELE ALEF THOMAS FLEGEL 《Veterinary radiology & ultrasound》2006,47(3):260-264
Two young adult Yorkshire terriers had neurologic signs consistent with forebrain and brainstem involvement or forebrain involvement alone. On magnetic resonance imaging studies there were asymmetric bilateral lesions mainly in the cerebral cortex, and in the diencephalon. These areas were hyperintense on T2-weighted and FLAIR images, but hypointense or isointense on T1-weighted images. Lesions had a varying degree of contrast enhancement. Areas which were isointense on T1-weighted images had no contrast enhancement or only foci of contrast enhancement. Lesions with hypointensity in T1-weighted images had no enhancement or more frequently ring-like enhancement around the lesion. Necrotizing encephalitis was confirmed pathohistologically in both dogs. The degree of contrast enhancement appeared to be related to the degree of lymphohistiocytic inflammation on histologic examination. 相似文献
105.
Andrew J. Brown MA VetMB DACVECC MRCVS Amy J. Alwood DVM Steven G. Cole DVM DACVECC 《Journal of Veterinary Emergency and Critical Care》2007,17(2):164-169
Objective: To describe a case of atrioventricular block and syncope secondary to systemic hypertension in a dog with malignant pheochromocytoma. Case Summary: A 13‐year‐old spayed female mixed‐breed dog presented following an acute onset of collapse. The dog was hypertensive and had paradoxical high‐grade second‐degree atrioventricular block with concurrent syncope. Initial emergent therapy included a nitroprusside infusion for the systemic hypertension and vagolytic therapy for the bradyarrhythmia. A left adrenal mass was seen on abdominal ultrasound and was further characterized by MRI. Following medical stabilization with phenoxybenzamine and propantheline, a left adrenalectomy was performed. Histological diagnosis was consistent with a malignant pheochromocytoma. Following tumor removal there has been no further hypertension, atrioventricular block or syncope. Unique information provided: This is the first documented case of a malignant pheochromocytoma presenting as syncope secondary to hypertension induced atrioventricular block. 相似文献
106.
SUSAN KRAFT E. J. EHRHART DAVID GALL LISA KLOPP PATRICK GAVIN RUSS TUCKER ROD BAGLEY HEGE KIPPENES CONSTANCE DEHAAN VINCE PEDROIA BETH PARTINGTON NATASHA OLBY 《Veterinary radiology & ultrasound》2007,48(1):1-7
Magnetic resonance imaging (MRI) examinations from 18 dogs with a histologically confirmed peripheral nerve sheath tumor (PNST) of the brachial plexus were assessed retrospectively. Almost half (8/18) had a diffuse thickening of the brachial plexus nerve(s), six of which extended into the vertebral canal. The other 10/18 dogs had a nodule or mass in the axilla (1.2-338 cm3). Seven of those 10 masses also had diffuse nerve sheath thickening, three of which extended into the vertebral canal. The majority of tumors were hyperintense to muscle on T2-weighted images and isointense on T1-weighted images. Eight of 18 PNSTs had only minimal to mild contrast enhancement and many (13/18) enhanced heterogeneously following gadolinium DTPA administration. Transverse plane images with a large enough field of view (FOV) to include both axillae and the vertebral canal were essential, allowing in-slice comparison to detect lesions by asymmetry of structures. Higher resolution, smaller FOV, multiplanar examination of the cervicothoracic spine was important for appreciating nerve root and foraminal involvement. Short tau inversion recovery, T2-weighted, pre and postcontrast T1-weighted pulse sequences were all useful. Contrast enhancement was critical to detecting subtle diffuse nerve sheath involvement or small isointense nodules, and for accurately identifying the full extent of disease. Some canine brachial plexus tumors can be challenging to detect, requiring a rigorous multiplanar multi-pulse sequence MRI examination. 相似文献
107.
108.
Gencheng Zhang Yanqing Wang Hongmei Zhang Shuhe Tang Weihua Tao 《Pesticide biochemistry and physiology》2007,87(1):23-29
The interaction between herbicide paraquat and human serum albumin (HSA) was investigated by fluorescence and UV/Vis absorption spectroscopy. Paraquat can strongly quench the intrinsic fluorescence of HSA by static quenching and nonradiative energy transferring; The hydrophobic and electrostatic interactions play a major role in stabilizing the complex. The binding site number n and apparent binding constant KA, corresponding thermodynamic parameters ΔG, ΔH, ΔS at different temperatures, were calculated. The distance r between donor (HSA) and acceptor (paraquat) was obtained according to fluorescence resonance energy transfer. The effect of paraquat on the conformation of HSA was analyzed using synchronous fluorescence spectroscopy. 相似文献
109.
THE DURAL TAIL SIGN IN THE DIAGNOSIS OF MENINGIOMAS 总被引:3,自引:0,他引:3
John P. Graham MVB MSc Susan M. Newell DVM MS Andra K. Voges DVM Gregory D. Roberts DVM MS Jay M. Harrison MS 《Veterinary radiology & ultrasound》1998,39(4):297-302
In humans the dural tail is a sign seen on contrast enhanced T1 weighted magnetic resonance images. This finding is considered specific for meningioma. The purpose of this study was to determine how often the dural tail occurs in cats and dogs and whether it is a specific sign for meningiomas in these species. MR examinations for eighteen dogs and four cats with proven diagnoses were reviewed. Diagnoses included ten meningiomas (seven dogs and three cats), three gliomas, two pituitary tumors, single examples of two other tumor types and five patients with mass lesions due to inflammatory disease. Contrast enhanced T1 weighted images were evaluated independently by three of the authors for the presence of a dural tail, without knowledge of the diagnoses. The results were compared to the diagnosis for each patient and the performance of individual reviewers compared. When their results were averaged, the reviewers reported the presence of a dural tail in 6 of 10 (60%) meningiomas, although detection varied between observers from 40% to 80%. Each reviewer had one false positive result, two reported a dural tail with a chromophobe adenocarcinoma and one with a toxoplasma meningoencephalitis. When a dural tail is seen an associated mass is most likely a meningioma. It is uncertain whether the dural tail represents neoplastic infiltration beyond the margins of the meningioma. This should be considered when planning treatment. 相似文献
110.
Debra K. Baird DVM John T. Hathcock DVM MS Steven A. Kincaid DVM MS PhD Paul F. Rumph DVM MS John Kammermann MS William R. Widmer DVM MS Denise Visco PhD Donald Sweet MD 《Veterinary radiology & ultrasound》1998,39(3):167-173
Six healthy adult male mongrel dogs underwent cranial cruciate ligament transection in the left stifle. Survey radiography of both stifles and low-field (0.064 T) MRI of the left stifle were performed preoperatively and at 2, 6, and 12 weeks postoperatively. Focal changes in signal intensity were seen with MRI in the subchondral bone of the medial tibial condyle at 2 and 6 weeks postoperatively. At 12 weeks postoperative, a cyst-like lesion was detected using MRI in the subchondral bone of the medial tibial condyle in 4 of 6 dogs and a less defined lesion at this site in the remaining 2 dogs. The cyst-like lesion was spherical in shape and showed typical characteristics of fluid with low signal intensity on T1-weighted images, high signal intensity on T2-weighted images and high signal intensity on inversion recovery images. The lesion was seen in the subchondral bone of the caudal medial and/or middle region of the tibial plateau slightly cranial to the insertion of the caudal cruciate ligament. No subchondral cysts were seen in the tibia on radiographs. Histopathologically, the tibia was characterized by a loose myxomatous phase of early subchondral cyst formation. 相似文献