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排序方式: 共有215条查询结果,搜索用时 62 毫秒
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Anja Hartmann Kathrin Becker Ulf Karsten Daniel Remias Markus Ganzera 《Marine drugs》2015,13(10):6291-6305
Mycosporine-like amino acids (MAAs), a group of small secondary metabolites found in algae, cyanobacteria, lichens and fungi, have become ecologically and pharmacologically relevant because of their pronounced UV-absorbing and photo-protective potential. Their analytical characterization is generally achieved by reversed phase HPLC and the compounds are often quantified based on molar extinction coefficients. As an alternative approach, in our study a fully validated hydrophilic interaction liquid chromatography (HILIC) method is presented. It enables the precise quantification of several analytes with adequate retention times in a single run, and can be coupled directly to MS. Excellent linear correlation coefficients (R2 > 0.9991) were obtained, with limit of detection (LOD) values ranging from 0.16 to 0.43 µg/mL. Furthermore, the assay was found to be accurate (recovery rates from 89.8% to 104.1%) and precise (intra-day precision: 5.6%, inter-day precision ≤6.6%). Several algae were assayed for their content of known MAAs like porphyra-334, shinorine, and palythine. Liquid chromatography-mass spectrometry (LC-MS) data indicated a novel compound in some of them, which could be isolated from the marine species Catenella repens and structurally elucidated by nuclear magnetic resonance spectroscopy (NMR) as (E)-3-hydroxy-2-((5-hydroxy-5-(hydroxymethyl)-2-methoxy-3-((2-sulfoethyl)amino)cyclohex-2-en-1-ylidene)amino) propanoic acid, a novel MAA called catenelline. 相似文献
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The porcine immune system differs in many aspects from that of humans and mice. Morphological differences in the lymphatic system (e.g. lymph nodes, Peyer's patches), and phenotypic differences in immune cells have been observed as well as functional differences in immune cell populations. Indeed, even the prenatal development of the embryonic piglet proceeds in a principally different way. However, it remains unclear to what extent these differences might contribute to the predisposition to and outcomes of bacterial infections, in particular those with zoonotic potential. In the following article we will review some of the peculiarities of the porcine immune system and consider possible implications for the course of infections in swine, with an emphasis on Salmonella serovars. 相似文献
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Florian Frers Maren Hellige Sandra Franke Christina Puff Uta Delling Karsten Feige 《Equine Veterinary Education》2023,35(2):e98-e104
A 7-year-old plains zebra (Equus quagga) mare was presented to the Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Germany as an emergency. The owner reported that the mare was unable to stand after a suspected traumatic episode at the home yard. The mare was transported in lateral recumbency in a trailer. Clinical examination revealed tachycardia (up to 102 beats/min), tachypnoea (28 breaths/min), mild fever (38.7°C) and clinical dehydration with elastic skin and dry and red mucous membranes. Neurological examination showed paraplegia with complete loss of nociception of the mid-thoracic region and caudal to it. In contrast, examination of the thoracic limbs revealed marked extensor rigidity and hyperaesthesia resulting in an enhanced acute response to minimal touch of the neck and shoulder region. Lateral radiographs of the thoracic vertebral column led to the diagnosis of a complete fracture of the vertebral body of the 7th thoracic (T) vertebra with suspected traumatic compression of the spinal cord. Post-mortem examination confirmed the diagnosis. Gross pathology revealed a complete comminuted fracture of T7 with marked compression of the spinal cord. This is the first report describing the clinical, radiological and pathological findings of a fracture of a thoracic vertebra leading to a Schiff-Sherrington syndrome in a zebra (Equus quagga). 相似文献
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Nöckler K Kutzer P Reif S Rosenberger N Draeger A Bahn P Göllner C Erlbeck C 《Berliner und Münchener tier?rztliche Wochenschrift》2003,116(9-10):368-372
Brucella (B.) canis was isolated from ejaculate of a 4-year old Korthals-Griffon male dog after occurrence of epididymitis and orchitis. Despite several trials of therapy with different antibiotics relapes occurred, with B. canis being isolated from ejaculate, blood and urine samples, respectively. Bacteriological examinations were added by serological testing over a period of about 1.5 years. During the study SAT serum titre steadily dropped from 1:200 to 1:50. By CFT, B. canis antibodies were detectable at the beginning with a titre of 1:320 and to the end of the study with titres between 1:80 and 1:160. 相似文献
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Agreement of high definition oscillometry with direct arterial blood pressure measurement at different blood pressure ranges in horses under general anaesthesia 下载免费PDF全文
ObjectiveTo determine the agreement of high definition oscillometry (HDO) with direct arterial blood pressure measurements in normotensive, hypotensive and hypertensive horses during general anaesthesia.Study designExperimental study.AnimalsSeven healthy warmblood horses, aged 3–11 years, weighing 470–565 kg.MethodsMeasurements from a HDO device with the cuff placed around the base of the tail were compared with pressures measured invasively from the facial artery. High blood pressures were induced by intravenous (IV) administration of dobutamine (5 μg kg−1 minute−1) over ten minutes followed by norepinephrine (0.1 mg kg−1 IV) and low pressures by increasing the inspired fraction of isoflurane and administration of nitroglycerine (0.05 mg kg−1 IV). For analysis three pressure levels were determined: high (MAP>110 mmHg), normal (60 mmHg
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Tocopherols (alpha, beta, gamma, and delta) and Trolox were found to deactivate triplet-excited riboflavin in homogeneous aqueous solution (7:3 v/v tert-butanol/water) with second-order reaction rates close to diffusion control [k2 between 4.8 x 10(8) (delta-tocopherol) and 6.2 x 10(8) L mol(-1) s(-1) (Trolox) at 24.0 +/- 0.2 degrees C] as determined by laser flash photolysis transient absorption spectroscopy. In aqueous buffer (pH 6.4) the rate constant for Trolox was 2.6 x 10(9) L mol(-1) s1 and comparable to the rate constant found for ascorbate (2.0 x 10(9) L mol(-1) s(-1)). The deactivation rate constant was found to be inferior in heterogeneous systems as shown for alpha-tocopherol and Trolox in aqueous Tween-20 emulsion (approximately by a factor of 4 compared to 7:3 v/v tert-butanol/water). Neither beta-carotene (7:3 v/v tert-butanol/water and Tween-20 emulsion), lycopene (7:3 v/v tert-butanol/water), nor crocin (aqueous buffer at pH 6.4, 7:3 v/v tert-butanol/water, and Tween-20 emulsion) showed any quenching on the triplet excited state of riboflavin. Therefore, all carotenoids seem to reduce the formation of triplet-excited riboflavin through an inner-filter effect. Activation parameters were based on the temperature dependence of the triplet-excited deactivation between 15 and 35 degrees C, and the isokinetic behavior, which was found to include purine derivatives previously studied, confirms a common deactivation mechanism with a bimolecular diffusion-controlled encounter with electron (or hydrogen atom) transfer as rate-determining step. DeltaH for deactivation by ascorbic acid, Trolox, and homologue tocopherols (ranging from 18 kJ mol(-1) for Trolox in Tween-20 emulsion to 184 kJ mol(-1) for ascorbic acid in aqueous buffer at pH 6.4) showed a linear dependence on DeltaS (ranging from -19 J mol(-1) K(-1) for Trolox in aqueous buffer at pH 6.4 to +550 J mol(-1) K(-1) for ascorbic acid in aqueous buffer pH 6.4). Among photooxidation products from the chemical quenching, lumicrome, alpha-tocopherol quinones and epoxyquinones, and alpha-tocopherol dimers were identified by ESI-QqTOF-MS. 相似文献