Single-Electron Transport in Ropes of Carbon Nanotubes     

M Bockrath  DH Cobden  PL McEuen  NG Chopra  A Zettl  A Thess  RE Smalley 《Science (New York, N.Y.)》1997,275(5308):1922-1925

The electrical properties of individual bundles, or "ropes," of single-walled carbon nanotubes have been measured. Below about 10 kelvin, the low-bias conductance was suppressed for voltages less than a few millivolts. In addition, dramatic peaks were observed in the conductance as a function of a gate voltage that modulated the number of electrons in the rope. These results are interpreted in terms of single-electron charging and resonant tunneling through the quantized energy levels of the nanotubes composing the rope.  相似文献   

Effect of accelerated aging on maize, sorghum, and sorghum meal     

C. M. McDonough  C. D. Floyd  R. D. Waniska  L. W. Rooney 《Journal of Cereal Science》2004,39(3):181

Accelerated aging at 50 °C significantly affected the physical and chemical properties of sorghum and maize. Aging caused associations between starch granules, protein matrix, and cell walls. During aging, floury areas of the endosperm became more corneous; as the endosperm hardened, strong associations between starch and protein developed, causing the endosperm to fracture through endosperm cells instead of along cell walls, which is common for non-aged maize. Aging significantly decreased the pasting viscosity of starch, molecular solubility at 85 °C and the molecular weight of solubilized starch. Solubility of albumins and globulins decreased while solubility of proteins extracted by a reducing agent and/or in alkaline pH increased during aging. Decreased solubility and functionality of starch and protein in aged grain appear to be due to protein oxidation.  相似文献   

Intravenous anaesthesia using detomidine, ketamine and guaiphenesin for laparotomy in pregnant pony mares     

Polly M Taylor  MA  VetMB  PhD  DVA  MRCVS  Stelio PL Luna  DVM  PhD  Kate L White MA  Vet MB  CertVA  MRCVS  Malcolm Bloomfield  Abigail L Fowden MA  PhD 《Veterinary anaesthesia and analgesia》2001,28(3):119-125

Objective To characterize intravenous anaesthesia with detomidine, ketamine and guaiphenesin in pregnant ponies. Animals Twelve pony mares, at 260–320 days gestation undergoing abdominal surgery to implant fetal and maternal vascular catheters. Materials and methods Pre‐anaesthetic medication with intravenous (IV) acepromazine (30 µg kg^?1), butorphanol (20 µg kg^?1) and detomidine (10 µg kg^?1) preceded induction of anaesthesia with detomidine (10 µg kg^?1) and ketamine (2 mg kg^?1) IV Maternal arterial blood pressure was measured directly throughout anaesthesia and arterial blood samples were taken at 20‐minute intervals for measurement of blood gases and plasma concentrations of cortisol, glucose and lactate. Anaesthesia was maintained with an IV infusion of detomidine (0.04 mg mL^?1), ketamine (4 mg mL^?1) and guaiphenesin (100 mg mL^?1) (DKG) for 140 minutes. Oxygen was supplied by intermittent positive pressure ventilation (IPPV) adjusted to maintain PaCO₂ between 5.0 and 6.0 kPa (38 and 45 mm Hg), while PaO₂ was kept close to 20.0 kPa (150 mm Hg) by adding nitrous oxide. Simultaneous fetal and maternal blood samples were withdrawn at 90 minutes. Recovery quality was assessed. Results DKG was infused at 0.67 ± 0.17 mL kg^?1 hour^?1 for 1 hour then reduced, reaching 0.28 ± 0.14 mL kg^?1 hour^?1 at 140 minutes. Arterial blood gas values and pH remained within intended limits. During anaesthesia there was no change in heart rate, but arterial blood pressure decreased by 10%. Plasma glucose and lactate increased (10‐fold and 2‐fold, respectively) and cortisol decreased by 50% during anaesthesia. Fetal umbilical venous pH, PO₂ and PCO₂ were 7.34 ± 0.06, 5.8 ± 0.9 kPa (44 ± 7 mm Hg) and 6.7 ± 0.8 kPa (50 ± 6 mm Hg); and fetal arterial pH, PO₂ and PCO₂ were 7.29 ± 0.06, 4.0 ± 0.7 kPa (30 ± 5 mm Hg) and 7.8 ± 1.7 kPa (59 ± 13 mm Hg), respectively. Surgical conditions were good but four ponies required a single additional dose of ketamine. Ponies took 60 ± 28 minutes to stand and recovery was good. Conclusions and clinical relevance Anaesthesia produced with DKG was smooth while cardiovascular function in mare and fetus was well preserved. This indicates that DKG infusion is suitable for maintenance of anaesthesia in pregnant equidae.  相似文献   

Single-dose pharmacokinetics and genotoxicity of metronidazole in cats     

Ivana Sekis  Kerry Ramstead  Mark Rishniw  Wayne S. Schwark  Sean P. McDonough  Richard E. Goldstein  Mark Papich  Kenneth W. Simpson 《Journal of Feline Medicine and Surgery》2009,11(2):60-68

  相似文献   

Pulmonary lymphomatoid granulomatosis in a cat.     

B A Valentine  J T Blue  J F Zimmer  A E Yeager  S P McDonough 《Journal of veterinary diagnostic investigation》2000,12(5):465-467

Pulmonary lymphomatoid granulomatosis was diagnosed in a 9-year-old castrated male domestic shorthair cat with a history of coughing, lethargy, and anorexia. Radiographic examination revealed multiple pulmonary opacities, consolidation of left lung lobes, and enlarged tracheobronchial lymph nodes. Cytologic examination of impression smears of abnormal pulmonary tissue revealed erythrocytes, lymphocytes, and macrophages, with scattered atypical lymphocytes and binucleate cells. Histopathologic evaluation of abnormal lung tissue revealed multiple, coalescing, densely cellular nodules composed of anaplastic and pleomorphic lymphocytes, with scattered binucleate and multinucleate cells. Marked infiltration and effacement of bronchiolar and vascular smooth muscle were present. These features are characteristic of lymphomatoid granulomatosis. To the authors' knowledge, this is the first report of pulmonary lymphomatoid granulomatosis in a cat.  相似文献   

Sustainable Environmental Education for a Sustainable Environment: Lessons from Thailand for Other Nations     

J. Gallagher  C. Wheeler  M. McDonough  B. Namfa 《Water, air, and soil pollution》2000,123(1-4):489-503

The Thailand Ministry of Education and Michigan State University collaborated to plan, design, implement, and evaluate this project in which school children and adults in 11 communities worked together to prevent forest degradation and improve forest quality. School children in grades 5 though 8 studied the causes and consequences of deforestation and forest degradation and brought the results of their investigations to local community members. This resulted in identification of local environmental problems that were forest-related and joint efforts in which adults and children worked together to resolve these problems. The results of this intergenerational work were very promising as children, adults, schools, communities, and the environment benefited from collaboration. Important lessons for others embarking this work are reported.  相似文献   

Helicobacter felis infection in dogs: effect on gastric structure and function.     

K W Simpson  P L McDonough  D Strauss-Ayali  Y F Chang  P Harpending  B A Valentine 《Veterinary pathology》1999,36(3):237-248

The relationship of Helicobacter felis, an organism that is observed in the stomachs of dogs, to gastric disease in dogs is unclear. The objective of this study was to determine if Helicobacter felis infection alters gastric morphology and gastric secretory function in dogs. Five specific-pathogen-free (SPF), Helicobacter-free Beagle dogs were examined before and for 26 weeks after inoculation with H. felis (ATCC 49179). Three SPF uninfected dogs served as controls. All five dogs became colonized by H. felis as determined by urease activity, histopathology, polymerase chain reaction, and transmission electron microscopic examination of serial gastric biopsies. The degree of colonization ranged from < 1 organism/400 x field to > 10 organisms/400 x field. The fundus, body, and cardia were most heavily colonized. Evaluation of gastric biopsies showed mild gastric inflammation and lymphoid follicles in both infected and uninfected dogs. There was no correlation between the number of organisms observed and the degree of gastric inflammation or number of lymphoid follicles. The gastric secretory axis, assessed by fasting and meal-stimulated plasma gastrin, mucosal gastrin and somatostatin immunoreactivity, fasting gastric pH, and pentagastrin-stimulated gastric acid secretion, was similar in both infected and uninfected dogs. Fasting gastric pH was not a reliable indicator of gastric secretory function. These findings suggest that H. felis may not be a gastric pathogen in dogs. However, the density of colonization and limited duration of infection should be considered when interpreting these findings.  相似文献   

Microdetermination of bioethanomethrin.     

D A George  L M McDonough 《Journal of the Association of Official Analytical Chemists》1975,58(4):781-784

A microanalytical method was developed for the determination of the experimental synthetic pyrethroid insecticide Bioethanomethrin ((5-benzyl-3-furyl) methyl trans-(+)-3-(cyclopentylidenemethyl) -2,2-dimethylcyclopropanecarboxylate). After saponification, trichloroacetyl chloride is used to form an ester from the acid moiety. Infrared and mass spectral data support the expected structures of the derivatives formed. Nanogram sensitivity is realized by utilizing a gas chromatograph with an electron capture detector.  相似文献   

Cooking Characteristics and Quality of Noodles from Food Sorghum     

E. L. Suhendro  C. F. Kunetz  C. M. McDonough  L. W. Rooney  R. D. Waniska 《Cereal Chemistry》2000,77(2):96-100

Three white food sorghums, ATx631*RTx436, ATxARG*RTx436, and SC283‐14, were decorticated, milled into flour and processed into 100% sorghum noodles. Flour, water, and salt (1%) were preheated using a hotplate or a microwave oven. The mixtures were put through a forming extruder to produce noodles. Extruded noodles were dried by three methods: air‐dry method (23°C, 48 hr); one‐stage (60°C, 30% rh, 3 hr), or two‐stage (60°C, 100% rh for 2 hr followed by 60°C, 30% rh for 2 hr). Noodles were evaluated dry and after cooking. Sorghum flours with smaller particle sizes yielded better noodles. The microwave preheating method yielded better noodles than the hot‐plate method. Stronger and firmer noodles, dry or cooked, were prepared using two‐stage drying compared with the other drying methods. Fine flour that was preheated using a microwave oven and dried using the two‐stage method gave the best noodles with moderate (10%) dry matter loss. Optimized processing conditions yielded sorghum noodles with good qualities when properly cooked.  相似文献