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991.
Amplification of c-erbB-2 and aggressive human breast tumors? 总被引:11,自引:0,他引:11
992.
993.
Squyres SW Arvidson RE Bell JF Brückner J Cabrol NA Calvin W Carr MH Christensen PR Clark BC Crumpler L Marais DJ d'Uston C Economou T Farmer J Farrand W Folkner W Golombek M Gorevan S Grant JA Greeley R Grotzinger J Haskin L Herkenhoff KE Hviid S Johnson J Klingelhöfer G Knoll AH Landis G Lemmon M Li R Madsen MB Malin MC McLennan SM McSween HY Ming DW Moersch J Morris RV Parker T Rice JW Richter L Rieder R Sims M Smith M Smith P Soderblom LA Sullivan R Wänke H Wdowiak T Wolff M Yen A 《Science (New York, N.Y.)》2004,306(5702):1698-1703
The Mars Exploration Rover Opportunity has investigated the landing site in Eagle crater and the nearby plains within Meridiani Planum. The soils consist of fine-grained basaltic sand and a surface lag of hematite-rich spherules, spherule fragments, and other granules. Wind ripples are common. Underlying the thin soil layer, and exposed within small impact craters and troughs, are flat-lying sedimentary rocks. These rocks are finely laminated, are rich in sulfur, and contain abundant sulfate salts. Small-scale cross-lamination in some locations provides evidence for deposition in flowing liquid water. We interpret the rocks to be a mixture of chemical and siliciclastic sediments formed by episodic inundation by shallow surface water, followed by evaporation, exposure, and desiccation. Hematite-rich spherules are embedded in the rock and eroding from them. We interpret these spherules to be concretions formed by postdepositional diagenesis, again involving liquid water. 相似文献
994.
Gellert R Rieder R Anderson RC Brückner J Clark BC Dreibus G Economou T Klingelhöfer G Lugmair GW Ming DW Squyres SW D'Uston C Wänke H Yen A Zipfel J 《Science (New York, N.Y.)》2004,305(5685):829-832
The alpha particle x-ray spectrometer on the Spirit rover determined major and minor elements of soils and rocks in Gusev crater in order to unravel the crustal evolution of planet Mars. The composition of soils is similar to those at previous landing sites, as a result of global mixing and distribution by dust storms. Rocks (fresh surfaces exposed by the rock abrasion tool) resemble volcanic rocks of primitive basaltic composition with low intrinsic potassium contents. High abundance of bromine (up to 170 parts per million) in rocks may indicate the alteration of surfaces formed during a past period of aqueous activity in Gusev crater. 相似文献
995.
Squyres SW Arvidson RE Ruff S Gellert R Morris RV Ming DW Crumpler L Farmer JD Marais DJ Yen A McLennan SM Calvin W Bell JF Clark BC Wang A McCoy TJ Schmidt ME de Souza PA 《Science (New York, N.Y.)》2008,320(5879):1063-1067
Mineral deposits on the martian surface can elucidate ancient environmental conditions on the planet. Opaline silica deposits (as much as 91 weight percent SiO2) have been found in association with volcanic materials by the Mars rover Spirit. The deposits are present both as light-toned soils and as bedrock. We interpret these materials to have formed under hydrothermal conditions and therefore to be strong indicators of a former aqueous environment. This discovery is important for understanding the past habitability of Mars because hydrothermal environments on Earth support thriving microbial ecosystems. 相似文献
996.
Levine JA Lanningham-Foster LM McCrady SK Krizan AC Olson LR Kane PH Jensen MD Clark MM 《Science (New York, N.Y.)》2005,307(5709):584-586
Obesity occurs when energy intake exceeds energy expenditure. Humans expend energy through purposeful exercise and through changes in posture and movement that are associated with the routines of daily life [called nonexercise activity thermogenesis (NEAT)]. To examine NEAT's role in obesity, we recruited 10 lean and 10 mildly obese sedentary volunteers and measured their body postures and movements every half-second for 10 days. Obese individuals were seated, on average, 2 hours longer per day than lean individuals. Posture allocation did not change when the obese individuals lost weight or when lean individuals gained weight, suggesting that it is biologically determined. If obese individuals adopted the NEAT-enhanced behaviors of their lean counterparts, they might expend an additional 350 calories (kcal) per day. 相似文献
997.
McSween HY Arvidson RE Bell JF Blaney D Cabrol NA Christensen PR Clark BC Crisp JA Crumpler LS Des Marais DJ Farmer JD Gellert R Ghosh A Gorevan S Graff T Grant J Haskin LA Herkenhoff KE Johnson JR Jolliff BL Klingelhoefer G Knudson AT McLennan S Milam KA Moersch JE Morris RV Rieder R Ruff SW De Souza PA Squyres SW Wänke H Wang A Wyatt MB Yen A Zipfel J 《Science (New York, N.Y.)》2004,305(5685):842-845
The Spirit landing site in Gusev Crater on Mars contains dark, fine-grained, vesicular rocks interpreted as lavas. Pancam and Mini-Thermal Emission Spectrometer (Mini-TES) spectra suggest that all of these rocks are similar but have variable coatings and dust mantles. Magnified images of brushed and abraded rock surfaces show alteration rinds and veins. Rock interiors contain =25% megacrysts. Chemical analyses of rocks by the Alpha Particle X-ray Spectrometer are consistent with picritic basalts, containing normative olivine, pyroxenes, plagioclase, and accessory FeTi oxides. M?ssbauer, Pancam, and Mini-TES spectra confirm the presence of olivine, magnetite, and probably pyroxene. These basalts extend the known range of rock compositions composing the martian crust. 相似文献
998.
999.
M. Clark K. Thomaseth L. Dirikolu D. C. Ferguson M. Hoenig 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2014,28(1):166-174
Background
Pioglitazone is a thiazolidinedione (TZD) insulin sensitizer approved for use in human type 2 diabetes mellitus. Therapeutic options for diabetes in cats are limited.Objective
To evaluate the effects of pioglitazone in obese cats, which are predisposed to insulin resistance, to assess its potential for future use in feline diabetes mellitus.Animals
A total of 12 obese purpose‐bred research cats (6 neutered males and 6 spayed females, 5–7 years of age, weighing 5.4–9.8 kg).Methods
Randomized, placebo‐controlled 3‐way crossover study. Oral placebo or pioglitazone (Actos™; 1 or 3 mg/kg) was administered daily for 7‐week periods, with IV glucose tolerance testing before and after each period.Results
Three mg/kg pioglitazone significantly improved insulin sensitivity (geometric mean [95% CI] 0.90 [0.64–1.28] to 2.03 [1.49–2.78] min −1pmol−1L; P = .0014 versus change with placebo), reduced insulin area under the curve during IVGTT (geometric mean [range] 27 [9–64] to 18 [6–54] min∙nmol/L; P = .0031 versus change with placebo), and lowered serum triglyceride (geometric mean [range] 71 [29–271] to 48 [27–75] mg/dL; P = .047 versus change with placebo) and cholesterol (geometric mean [range] 187 [133–294] to 162 [107–249] mg/dL; P = .0042 versus change with placebo) concentrations in the obese cats. No adverse effects attributable to pioglitazone were evident in the otherwise healthy obese cats at this dosage and duration.Conclusions and Clinical Importance
Results of this study support a positive effect of pioglitazone on insulin sensitivity and lipid metabolism in obese cats, and suggest that further evaluation of the drug in cats with diabetes mellitus or other metabolic disorders might be warranted. 相似文献1000.