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1.
目的 大量富集三裂叶蟛蜞菊倍半萜内酯A,B(WTA,WTB)。方法 采用气相色谱法测定WTA和WTB,并以WTA和WTB的含量、洗脱率、精制度为考察指标,研究D101大孔树脂吸附WTA和WTB的工艺条件及参数。结果 通过大孔树脂吸附后,WTA和WTB的洗脱率达90%,50%乙醇洗脱部分中WTA和WTB的含量为总固物的4.01%~4.09%。结论 可以采用大孔树脂富集WTA和WTB。 相似文献
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BELIN VINCENT; HODGE THOMAS; PICAUT PHILIPPE; JORDAN ROY; ALGATE CAROL; GOSSELIN SYLVIE; NOHYNEK GERHARD; CAVERO ICILIO 《Toxicological sciences》1996,31(2):259-267
Aprikalim is a potent, specific, and selective opener of ATP-sensitiveK+ (KATP) channels. By virtue of this pharmacological property,aprikalim affords cardioprotection in experimental models ofischemia/reperfusion injury, and, at higher doses, also causesperipheral or coronary vasodilatation. Direct-acting peripheralvasodilators can cause myocardial lesions, particularly in ratsand dogs. However, unexpectedly, aprikalim produced this effectalso in monkeys. Thus, the primary aim of this investigationwas to assess whether in monkeys these myocardial lesions werethe direct or indirect consequence of the vascular effects ofaprikalim. Cyno-mologus monkeys were given the ß-adrenoceptorantagonist nado-lol (2 mg/kg po, twice daily) for 4 consecutivedays. On the third and fourth day of the experiment, they receivedaprikalim (1 mg/kg po). In another series, two monkeys carryingtelemetry transmitters for blood pressure and heart rate measurementswere also given aprikalim or its vehicle. Finally, aprikalim(1 mg/kg po for 2 days) or its vehicle was administered to ratswhich were concurrently treated with the ß-adrenoceptorantagonist atenolol (5 mg/ kg sc) or its vehicle. In cynomologusmonkeys, aprikalim produced focal and multifocal myocardialnecrosis of minimal to moderate intensity in or near the papillarymuscles of the left ventricle. These effects were abrogatedby nadolol. Similarly, necrotic lesions were caused by aprikalimonly in those rats which had not been pretreated with atenolol.In monkeys, aprikalim produced a marked and long-lasting decreasein aortic blood pressure, accompanied by an even more prolongedtachycardia. These results demonstrate that aprikalim can producemyocardial necrosis not only in rats but also in monkeys. Toour knowledge, this is the first time that such adverse effectsare reported for a vasodilator in monkeys. More importantly,these effects were prevented by blocking cardiac ß-adrenoceptors.Thus, the myocardial lesions produced by aprikalim may be attributedto its profound and prolonged hemodynamic effects. 相似文献
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VINCENT J. HYAMS 《Clinical otolaryngology》1978,3(2):117-126
The differential diagnosis of approximately 2000 cases of palatine tonsillar malignancy contained in the Otolaryngic Pathology Registry of the Armed Forces Institute of Pathology are presented to include basic statistics of age, race and sex. These statistics and others from the World English language medical literature are compared and discussed briefly. Pertinent information points out the overwhelming predominance of squamous (epidermoid) carcinoma, the delayed medical attention of patients and hence the advanced clinical state of the disease when first diagnosed, the involvement of cervical lymph nodes in the majority of cases and the causative relationship of alcoholism. A discussion of the various histological types of tonsillar carcinoma suggests a simplification of the current microscopic classification. 相似文献
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Determination of Pacing Capture in Implantable Defibrillators: Benefit of Evoked Response Detection Using RV Coil to Can Vector 总被引:1,自引:1,他引:1
VINCENT SPLETT JANE M. TRUSTY DAVID L. HAYES PAUL A. FRIEDMAN 《Pacing and clinical electrophysiology : PACE》2000,23(11):1645-1650
SPLETT, V., et al. : Determination of Pacing Capture in Implantable Defibrillators: Benefit of Evoked Response Detection Using RV Coil to Can Vector. Automatic detection of capture in ICDs would be useful for ensuring normal pacing function and lead integrity and may increase device longevity. Evoked response detection can be difficult due to postpace polarization. Polarization on the RV coil to can vector, however, should be absent when pacing with a true bipolar lead (pace tip to ring). Polarization on the RV coil to can vector should be low in an integrated bipolar lead due to the large surface area of the coil. Ventricular-paced responses were prospectively recorded in 20 patients during ICD implantation or replacement. Capture and loss of capture responses were noted during threshold searches with electrograms recorded between the RV coil and can. A detector was designed to discriminate between capture and noncapture-paced responses using data from the first 11 patients and validated on the remaining 9. The detector had a sensitivity of 99.9% (detected capture on capture beats), and had a specificity of 100% (detected no capture on noncapture beats) for all lead configurations. There was no measurable polarization with true bipolar leads. In integrated bipolar leads, maximum polarization ranged from 0.0 to 16.7mV. In conclusion, paced evoked responses can be detected in ICDs using the RV coil to can vector using standard pacing waveforms. Special polarization reducing pacing waveforms are not required. These observations could be used to design ICDs with automatic pacing threshold detection. 相似文献
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Variation in the Amount of Hemoglobin S in a Patient with Sickle Cell Trait and Megaloblastic Anemia 总被引:4,自引:0,他引:4
A patient with sickle cell trait and nutritional megaloblastic anemia wasfound to have a much smaller proportion of hemoglobin S during the megaloblastic phase than after recovery. This observation suggests preferential synthesis of hemoglobin A by megaloblastic bone marrow in the presence of theA-S trait. Submitted on July 30, 1962 Accepted on November 9, 1962 相似文献
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Charlotte C. GUPTA Michelle DOMINIAK Katya KOVAC Amy C. REYNOLDS Sally A. FERGUSON Cassie J. HILDITCH Madeline SPRAJCER Grace E. VINCENT 《Industrial health》2022,60(2):91
Due to the unpredictable nature of working time arrangements, on-call workers experience regular disruption to sleep, particularly if woken by calls. Sleep disruption can impact long term physical and mental health, next day performance, and importantly, performance immediately after waking. To reduce the impact of performance impairments upon waking (i.e., reducing sleep inertia), research has investigated strategies to promote alertness (e.g., bright light, caffeine, and exercise). This review puts forth on-call workers who are likely to return to sleep after a call, it is also important to consider the impact of these sleep inertia countermeasures on subsequent sleep. Future research should build on the preliminary evidence base for sleep inertia countermeasures by examining the impact on subsequent sleep. This research is key for both supporting alertness and performance during a call (“switching on”) and for allowing the on-call worker to return to sleep after a call (“switching off”). 相似文献
9.
Determining the Optimal Dose of Adenosine for Unmasking Dormant Pulmonary Vein Conduction Following Atrial Fibrillation Ablation: Electrophysiological and Hemodynamic Assessment. DORMANT‐AF Study 下载免费PDF全文
SANDEEP PRABHU M.B.B.S. VINCENT MACKIN B.Sc. ALEX J.A. MCLELLAN M.B.B.S. Ph.D. TUONG PHAN M.B.B.S. DESMOND MCGLADE M.B.B.S. LIANG‐HAN LING M.B.B.S. Ph.D. KAH Y. PECK M.B.B.S. ALEXANDR VOSKOBOINIK M.B.B.S. BUPESH PATHIK M.B.B.S. F.R.A.C.P. CHRISHAN J. NALLIAH M.B.B.S. GEOFF R. WONG M.B.B.S. SONIA M. AZZOPARDI R.N. GEOFFREY LEE M.B.Ch.B. Ph.D. JUSTIN MARIANI M.B.B.S. Ph.D. ANDREW J. TAYLOR M.B.B.S. Ph.D. JONATHAN M. KALMAN M.B.B.S. Ph.D. F.H.R.S. PETER M. KISTLER M.B.B.S. Ph.D. F.H.R.S. 《Journal of cardiovascular electrophysiology》2017,28(1):13-22
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DOROTHY BRUCK MICHELLE BALL IAN THOMAS VINCENT ROUILLARD 《Journal of sleep research》2009,18(2):196-203
How arousal thresholds vary with different sounds is a critical issue for emergency awakenings, especially as sleepers are dying in fires despite having a working smoke alarm. Previous research shows that the current high-pitched (3000+ Hz) smoke alarm signal is significantly less effective than an alternative signal, the 520 Hz square wave, in all populations tested. However, as the number of sounds tested has been small further research is needed. Here we measured auditory arousal thresholds (AATs) across signals with a range of characteristics to determine the most effective waking signal. Thirty-nine young adults participated over three nights. In Part A, nine signals were presented in stage 4 sleep with ascending decibel levels. Signals were short beeps in the low- to mid-frequency range with different spectral complexities: square waves, pure tones, whoops and white noise. Part B manipulated temporal patterns, inserting silences of 0, 10 and 21 s after each 12 s of beeps. It was found that the low-frequency (400 and 520 Hz) square waves yielded significantly lower AATs than the alternatives. A trend was found across the three temporal manipulations, with a 10 s intervening silence showing some advantage. These findings support earlier research indicating that the best sound for awakening from deep sleep is a low-frequency square wave. It is argued that the signal with the lowest response threshold when awake may be the same as the most arousing signal when asleep, especially where the sleeper processes the signal as meaningful. 相似文献