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排序方式: 共有343条查询结果,搜索用时 15 毫秒
1.
Palytoxin, a highly toxic natural product isolated from zoanthids of the genus Palythoa, is accumulated by a wide range of fishes and marine invertebrates used as food in the Indo-Pacific. It is responsible for many incidents of human morbidity and mortality. The toxin is a potent smooth muscle spasmogen. The cause of the contraction of smooth muscle is unclear, but recent work strongly suggests that it is primarily initiated by the release of neurotransmitters from the motor innervation of the smooth muscle. We show here that palytoxin caused the swelling of the muscle cells and some internal organelles of the anococcygeus muscle of the rat, but no substantial structural damage to the tissue. Axons and Schwann cells were also swollen but the most dramatic feature was the depletion of synaptic vesicles from putative release sites in the axons. Some axons were physically damaged following exposure to the toxin, but this was relatively uncommon (<10% of all axons studied). In the majority of axons there was no damage to nerve terminal membranes, but there was damage to mitochondria. The depletion of vesicles involved all types – clear, dense-cored, large and small. Our observations and pharmacological data gathered elsewhere, provide a neuropathological basis for the spasmogenic activity of palytoxin. 相似文献
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Heather J. Zar Michael J. Asmus Eugene G. Weinberg 《Pediatric allergy and immunology》2002,13(3):217-222
Inhaled therapy using a metered‐dose inhaler (MDI) with attached spacer has been increasingly recognized as the optimal method for delivering asthma medication for acute attacks and chronic prophylaxis. However, in developing countries the cost and availability of commercially produced spacers limit the use of MDI‐spacer delivery systems. A 500‐ml plastic bottle has been recently adapted to function as a spacer. This article reviews the current data on the efficacy of this bottle‐spacer and discusses its advantages and limitations. It is concluded that a modified 500‐ml plastic bottle is an effective spacer; modification and use of this device should be incorporated into international guidelines for the management of children with asthma. 相似文献
3.
Perez Alexander Brittain Kirsty Phillips Nicole Stein Dan J. Zar Heather J. Myer Landon Hoare Jacqueline 《AIDS and behavior》2022,26(2):434-442
AIDS and Behavior - The effect of chronic HIV-infection on psychological adjustment, including the impact of HIV-related stigma in perinatally HIV-infected (PHIV+) youth across Africa is largely... 相似文献
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Zar HJ Workman L Isaacs W Munro J Black F Eley B Allen V Boehme CC Zemanay W Nicol MP 《Clinical infectious diseases》2012,55(8):1088-1095
Background.?A rapid diagnosis of pediatric pulmonary tuberculosis (PTB) using Xpert MTB/RIF (Mycobacterium tuberculosis/rifampicin) automated testing on induced sputum (IS) is possible, but the capacity for performing IS is limited. The diagnosis using a nasopharyngeal aspirate (NPA), which can be non-invasively obtained, is desirable. Methods.?Paired specimens (NPA and IS) were tested using smear, liquid culture and Xpert. The diagnostic accuracy of Xpert and smear was compared with culture for different specimens in children with suspected PTB. Results.?There were 535 children [median age 19 months, 117 (21·9%) HIV-infected] who had one IS and one NPA specimen; 396 had two paired specimens. A positive smear, Xpert test or culture occurred in 30 (5.6%), 81 (15.1%) and 87 children (16.3%), respectively. The culture yield was higher from IS (84/87, 96.6%) vs NPA (61/87, 70.1%, P?.001). Amongst children with two paired specimens, 63 culture-confirmed cases occurred [60 (95.2%) IS vs 48 (76.2%) NPA, P?=?.002]. The sensitivity of two Xpert tests was similar for IS and NPAs [(45/63) 71% vs (41/63) 65%, P?=?.444)]; the sensitivity of smear was lower for IS (21/63, 33%) and NPA (16/63, 25%). The incremental yield from a second IS was 9 cases (17.6%) by culture and 9 (25%) by Xpert testing; a second NPA increased the culture yield by 10 (26.3%) and Xpert by 11 (36.7%). Xpert specificity was 99.1% (98.1-100) for IS and 98.2% (96.8-99.6) for NPAs. Xpert testing provided faster results than culture (median 0 vs 15 days, P?.001). Conclusions.?Xpert testing on 2 NPAs is useful in children with suspected PTB, particularly in settings where IS and culture are not feasible. 相似文献
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May Thu Zar Myint Masaki Hada Hirotaka Inoue Tatsuki Marui Takeshi Nishikawa Yuta Nishina Susumu Ichimura Masayoshi Umeno Aung Ko Ko Kyaw Yasuhiko Hayashi 《RSC advances》2018,8(64):36563
As a thermoelectric (TE) material suited to applications for recycling waste-heat into electricity through the Seebeck effect, poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonic acid) (PEDOT:PSS) is of great interest. Our research demonstrates a comprehensive study of different post-treatment methods with nitric acid (HNO3) to enhance the thermoelectric properties of PEDOT:PSS. The optimum conditions are obtained when PEDOT:PSS is treated with HNO3 for 10 min at room temperature followed by passing nitrogen gas (N2) with a pressure of 0.2 MPa. Upon this treatment, PEDOT:PSS changes from semiconductor-like behaviour to metal-like behaviour, with a simultaneous enhancement in the electrical conductivity and Seebeck coefficient at elevated temperature, resulting in an increase in the thermoelectric power factor from 0.0818 to 94.3 μW m−1 K−2 at 150 °C. The improvement in the TE properties is ascribed to the combined effects of phase segregation and conformational change of the PEDOT due to the weakened coulombic attraction between PEDOT and PSS chains by nitric acid as well as the pressure of the N2 gas as a mechanical means.As a thermoelectric (TE) material suited to applications for recycling waste-heat into electricity through the Seebeck effect, poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonic acid) (PEDOT:PSS) is of great interest. 相似文献
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Piotr Orzechowski MD Ryszard Piotrowicz MD PhD Wojciech Zaręba MD PhD Renata Główczyńska MD PhD Dominika Szalewska MD PhD Sławomir Pluta MD PhD Robert Irzmański MD PhD Zbigniew Kalarus MD PhD Maciej Banach MD PhD Grzegorz Opolski MD PhD Michael J. Pencina PhD Ilona Kowalik PhD Ewa Piotrowicz MD PhD FESC 《Annals of noninvasive electrocardiology》2021,26(6):e12887
10.
Woo So-Yeun Wong Chin Piow Win Nwet Nwet Lae Khine Zar Wynn Woo Bokyoung Elsabbagh Sherif Adel Liu Qian Qian Ngwe Hla Morita Hiroyuki 《Journal of natural medicines》2019,73(4):805-813
Journal of Natural Medicines - Jatropha multifida is a medicinal plant that belongs to the Euphorbiaceae family. Our investigation revealed that the chloroform extract of J. multifida stems showed... 相似文献