Biomimetic Pathways for Assembling Inorganic Thin Films   总被引：3，自引：0，他引：3  

IA Aksay  M Trau  S Manne  I Honma  N Yao  L Zhou  P Fenter  PM Eisenberger  SM Gruner 《Science (New York, N.Y.)》1996,273(5277):892-898

Living organisms construct various forms of laminated nanocomposites through directed nucleation and growth of inorganics at self-assembled organic templates at temperatures below 100°C and in aqueous solutions. Recent research has focused on the use of functionalized organic surfaces to form continuous thin films of single-phase ceramics. Continuous thin films of mesostructured silicates have also been formed on hydrophobic and hydrophilic surfaces through a two-step mechanism. First, under acidic conditions, surfactant micellar structures are self-assembled at the solid/liquid interface, and second, inorganic precursors condense to form an inorganic-organic nanocomposite. Epitaxial coordination of adsorbed surfactant tubules is observed on mica and graphite substrates, whereas a random arrangement is observed on amorphous silica. The ability to process ceramic-organic nanocomposite films by these methods provides new technological opportunities.  相似文献   

The Seismic Structure of the Sun     

DO Gough  AG Kosovichev  J Toomre  E Anderson  HM Antia  S Basu  B Chaboyer  SM Chitre  J Christensen-Dalsgaard  WA Dziembowski  A Eff-Darwich  JR Elliott  PM Giles  PR Goode  JA Guzik  JW Harvey  F Hill  JW Leibacher  MJPFG Monteiro  O Richard  T Sekii  H Shibahashi  M Takata  MJ Thompson  S Vauclair  SV Vorontsov 《Science (New York, N.Y.)》1996,272(5266):1296-1300

Global Oscillation Network Group data reveal that the internal structure of the sun can be well represented by a calibrated standard model. However, immediately beneath the convection zone and at the edge of the energy-generating core, the sound-speed variation is somewhat smoother in the sun than it is in the model. This could be a consequence of chemical inhomogeneity that is too severe in the model, perhaps owing to inaccurate modeling of gravitational settling or to neglected macroscopic motion that may be present in the sun. Accurate knowledge of the sun's structure enables inferences to be made about the physics that controls the sun; for example, through the opacity, the equation of state, or wave motion. Those inferences can then be used elsewhere in astrophysics.  相似文献   

Lateralized cognitive processes and lateralized task control in the human brain     

Stephan KE  Marshall JC  Friston KJ  Rowe JB  Ritzl A  Zilles K  Fink GR 《Science (New York, N.Y.)》2003,301(5631):384-386

The principles underlying human hemispheric specialization are poorly understood. We used functional magnetic resonance imaging of letter and visuospatial decision tasks with identical word stimuli to address two unresolved problems. First, hemispheric specialization depended on the nature of the task rather than on the nature of the stimulus. Second, analysis of frontal candidate regions for cognitive control showed increased coupling between left anterior cingulate cortex (ACC) and left inferior frontal gyrus during letter decisions, whereas right ACC showed enhanced coupling with right parietal areas during visuospatial decisions. Cognitive control is thus localized in the same hemisphere as task execution.  相似文献   

Bottom currents in the hudson canyon     

Keller GH  Lambert D  Rowe G  Staresinic N 《Science (New York, N.Y.)》1973,180(4082):181-183

In-place measurements of the bottom currents in the Hudson Canyon reveal that the current regime is characterized by a pronounced reversal of flow up and down the canyon. Velocities are commonly of the order of 8 to 15 centimeters per second, reaching 27 centimeters per second on occasion in the upper and central portion of the canyon. Although alpha 2.5-day recording of currents showed a net transport upcanyon, a combination of 66 current measurements from the submersible Alvin, the analysis of sediment texture and organic carbon, and the determination of the benthic fauna-nutrient relationship indicate that over the long term there is a net transport of fine material through the canyon to the outer continenital rise.  相似文献   

Performance and variability of diploid and tetraploid potato families     

P. R. Rowe 《American Journal of Potato Research》1967,44(8):263-271

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Quantitative variation in diploid potatoes     

P. R. Rowe 《American Journal of Potato Research》1969,46(1):14-17

Fifty clones selected from crosses between Phureja and Tuberosum haploids and 24 Tuberosum haploids were used to produce two Design I trials, and one Design II trial. Tests were conducted for 2 years at one location, and estimates were obtained for quantitative genetic variance for tuber number and weight. Estimates of genetic variance for tuber number were large, with approximately equal additive and dominance components. Additive genetic variance was the larger component for tuber weight for two of the three estimates. More results from other populations are needed to establish the relative importance of the quantitative genetic components in potatoes.  相似文献   

Potato early dying—A serious threat to the potato industry     

Randall C. Rowe 《American Journal of Potato Research》1985,62(4):157-161

Potato early dying (PED) is characterized by a loss of plant vigor during mid to late summer followed by senescence and death of the crop a few weeks prior to normal maturity. This disease is of serious importance in areas of long-term or intensive potato production and is largely uncontrolled. Symptoms of PED, which are difficult to distinguish from normal senescence, especially in early-maturing cultivars, are uneven chlorosis and necrosis of vines and tan discoloration of vascular tissues. The basic cause of PED is the soil fungusVerticillium. Two species are involved—V. alboatrum predominating in cooler areas andV. dahliae in warmer areas. Both fungi commonly occur in cultivated soils and persist as melanized hyphae or microsclerotia, respectively. Infection occurs through roots followed by colonization of the vascular system. Contamination of uninfested fields can occur by wind or mechanical movement of soil-borne propagules or introduction of infested seed stock. AlthoughVerticillium is the primary pathogen in potato early dying, other soil organisms are involved, resulting in a “disease complex.” Research is under way in many areas to further our understanding of these pathogenic interactions and to exploit this knowledge for use in new systems of prediction and control.  相似文献   

Clinical efficacy and safety of a water‐soluble micellar paclitaxel (Paccal Vet) in canine mastocytomas     

P. Rivera  N. Åkerlund‐Denneberg  K. Bergvall  M. Kessler  A. Rowe  M. Willmann  G. Persson  G. Kastengren Fröberg  S. Westberg  H. von Euler 《The Journal of small animal practice》2013,54(1):20-27

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WHOLE‐BODY BIODISTRIBUTION OF 3′‐DEOXY‐3′‐[18F]FLUOROTHYMIDINE (18FLT) IN HEALTHY ADULT CATS     

Joshua A. Rowe  Federica Morandi  Jonathan S. Wall  Murthy Akula  Stephen J. Kennel  Dustin Osborne  Emily B. Martin  Gina D. Galyon  Misty J. Long  Alan C. Stuckey  Amy K. LeBlanc 《Veterinary radiology & ultrasound》2013,54(3):299-306

Positron emission tomography/computed tomography (PET/CT) utilizing 3′‐deoxy‐3′‐[¹⁸F]fluorothymidine (¹⁸FLT), a proliferation tracer, has been found to be a useful tool for characterizing neoplastic diseases and bone marrow function in humans. As PET and PET/CT imaging become increasingly available in veterinary medicine, knowledge of radiopharmaceutical biodistribution in veterinary species is needed for lesion interpretation in the clinical setting. The purpose of this study was to describe the normal biodistribution of ¹⁸FLT in adult domestic cats. Imaging of six healthy young adult castrated male cats was performed using a commercially available PET/CT scanner consisting of a 64‐slice helical CT scanner with an integrated whole‐body, high‐resolution lutetium oxy‐orthosilicate (LSO) PET scanner. Cats were sedated and injected intravenously with 108.60 ± 2.09 (mean ± SD) MBq of ¹⁸FLT (greater than 99% radiochemical purity by high‐performance liquid chromatography). Imaging was performed in sternal recumbency under general anesthesia. Static images utilizing multiple bed positions were acquired 80.83 ± 7.52 (mean ± SD) minutes post‐injection. Regions of interest were manually drawn over major parenchymal organs and selected areas of bone marrow and increased tracer uptake. Standardized uptake values were calculated. Notable areas of uptake included hematopoietic bone marrow, intestinal tract, and the urinary and hepatobiliary systems. No appreciable uptake was observed within brain, lung, myocardium, spleen, or skeletal muscle. Findings from this study can be used as baseline data for future studies of diseases in cats.  相似文献   

Macronutrient concentration in plant parts of cotton fertilized with broiler litter in a marginal upland soil     

H. Tewolde  M.W. Shankle  A. Adeli  K.R. Sistani  D.E. Rowe 《Soil & Tillage Research》2009,105(1):1-11

Effectiveness of surface-applied unincorporated broiler litter as a fertilizer relative to conventional inorganic fertilizers under no-till or conventional-till cotton (Gossypium hirsutum L.) production systems in the upland soils of the southern and southeastern USA is not well documented. The objectives of this research were to (1) test if broiler litter improves plant macronutrient (N, P, K, and Mg) nutrition of cotton above that of cotton fertilized with conventional inorganic fertilizers and (2) determine if lack of incorporating litter into the soil reduces macronutrient concentration in cotton plant parts in an upland soil considered marginal for cotton. Six treatments consisting of an unfertilized control, a fertilized standard (STD), two litter-only, and two litter plus inorganic N as urea–ammonium nitrate solution (UAN) were tested in two adjacent fields, one under no-till (NT) and the other under conventional-till (CT) systems. Litter alone, UAN, or a combination of litter plus UAN were applied to supply 101 kg ha⁻¹ plant available N assuming nearly all of the UAN-N and 50% of the total litter N becomes plant available during the cotton growing season. Concentration of N, P, K, and Mg were measured in leaves, stems, and reproductive parts on three or four dates between early flowering and maturity. Cotton fertilized with the litter-only treatments always had less N concentration but greater P and K concentration in leaves, stems, and reproductive parts than cotton that received the STD treatment. Leaf and stem Mg concentration seems to depend on the N concentration in these plant parts. Lack of incorporating litter into the soil reduced N concentration in nearly all plant parts at all growth stages, suggesting some amount of the litter-derived N is lost due to lack of incorporation. Lack of incorporation also reduced leaf and stem Mg concentration, which seemed to be due to its reducing effect on N concentration. Unlike N and Mg, lack of incorporation did not consistently affect concentrations of P and K in all plant parts. Regardless of the incorporation treatment, fertilization with the litter-only treatments increased tissue P and K concentration and supported lint yield exceeding that of the STD without increasing tissue N concentration.  相似文献