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A complete set of pika taxa, belonging to the subgenus Ochotona, was studied using craniometric and multilocus genetic analyses. We examined 1,007 skulls, covering the entire distribution range of the subgenus, as well as the mitochondrial COI gene and three nuclear introns in 31 specimens, representing nearly all taxa in question. An additional set of 167 COI gene sequences and 357 cytb gene sequences was analysed to enlarge the geographical extent of genetic data and to compare the results with previous publications. We found that the subgenus consists of eight species. One of them, Ochotona morosa, is elevated to the full species rank for the first time. The name of this species is given preliminarily and should be studied additionally. Several cases of interspecies hybridisation were found, which indicates that mitochondrial DNA cannot be used for species identification in this subgenus. Taxon Ochotona qionglaiensis, which was recently described as a separate species, represents a relic mitochondrial lineage of Ochotona thibetana. Another recently described species, Ochotona yarlungensis, is a Nubra pika with its native mitochondrial DNA, firstly found for this species. Intraspecies variation was analysed for several species for the first time. Thus, new subspecies (Ochotona thibetana fengii ssp. n.) was found within O. thibetana.  相似文献   
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Oxygen and glucose biosensors have been designed, fabricated, characterized and optimized for real-time continuous monitoring on a new smart catheter for use in patients with traumatic brain injury (TBI). Oxygen sensors with three-electrode configuration were designed to achieve zero net oxygen consumption. Glucose sensors were based on the use of platinum nanoparticle-enhanced electrodes that were modified with polycation and glucose oxidase immobilized by chitosan matrix. An iridium oxide electrode was developed to work as a biocompatible reference electrode with enhanced durability and stability in the biological solutions. A study of the effect of temperature on oxygen sensor performance, and both temperature and oxygen effects on glucose sensor performance were accomplished to enhance their operative stability and provide useful information for in vivo applications. A new methodology for automatic correction of the temperature and oxygen dependence of biosensor outputs is demonstrated through programmed LabView™ software. In vitro experiments in both physiological and pathophysiological ranges (oxygen: 0–60 mmHg; glucose: 0.1–10 mM; temperature: 25–40 °C) with clinical samples of cerebrospinal fluid obtained from TBI patients have demonstrated stable measurements with enhanced accuracy, indicating the feasibility of the sensors for a real-time continuous in vivo monitoring.  相似文献   
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Minute ring-shaped particles in cultured cells of malignant origin   总被引:3,自引:0,他引:3  
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