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91.
Wentworth P McDunn JE Wentworth AD Takeuchi C Nieva J Jones T Bautista C Ruedi JM Gutierrez A Janda KD Babior BM Eschenmoser A Lerner RA 《Science (New York, N.Y.)》2002,298(5601):2195-2199
Recently, we showed that antibodies catalyze the generation of hydrogen peroxide (H2O2) from singlet molecular oxygen (1O2*) and water. Here, we show that this process can lead to efficient killing of bacteria, regardless of the antigen specificity of the antibody. H2O2 production by antibodies alone was found to be not sufficient for bacterial killing. Our studies suggested that the antibody-catalyzed water-oxidation pathway produced an additional molecular species with a chemical signature similar to that of ozone. This species is also generated during the oxidative burst of activated human neutrophils and during inflammation. These observations suggest that alternative pathways may exist for biological killing of bacteria that are mediated by potent oxidants previously unknown to biology. 相似文献
92.
Rauch A Thiel CT Schindler D Wick U Crow YJ Ekici AB van Essen AJ Goecke TO Al-Gazali L Chrzanowska KH Zweier C Brunner HG Becker K Curry CJ Dallapiccola B Devriendt K Dörfler A Kinning E Megarbane A Meinecke P Semple RK Spranger S Toutain A Trembath RC Voss E Wilson L Hennekam R de Zegher F Dörr HG Reis A 《Science (New York, N.Y.)》2008,319(5864):816-819
Fundamental processes influencing human growth can be revealed by studying extreme short stature. Using genetic linkage analysis, we find that biallelic loss-of-function mutations in the centrosomal pericentrin (PCNT) gene on chromosome 21q22.3 cause microcephalic osteodysplastic primordial dwarfism type II (MOPD II) in 25 patients. Adults with this rare inherited condition have an average height of 100 centimeters and a brain size comparable to that of a 3-month-old baby, but are of near-normal intelligence. Absence of PCNT results in disorganized mitotic spindles and missegregation of chromosomes. Mutations in related genes are known to cause primary microcephaly (MCPH1, CDK5RAP2, ASPM, and CENPJ). 相似文献
93.
Tews I Findeisen F Sinning I Schultz A Schultz JE Linder JU 《Science (New York, N.Y.)》2005,308(5724):1020-1023
Class III adenylyl cyclases contain catalytic and regulatory domains, yet structural insight into their interactions is missing. We show that the mycobacterial adenylyl cyclase Rv1264 is rendered a pH sensor by its N-terminal domain. In the structure of the inhibited state, catalytic and regulatory domains share a large interface involving catalytic residues. In the structure of the active state, the two catalytic domains rotate by 55 degrees to form two catalytic sites at their interface. Two alpha helices serve as molecular switches. Mutagenesis is consistent with a regulatory role of the structural transition, and we suggest that the transition is regulated by pH. 相似文献
94.
OBJECTIVE: To examine global food demand patterns and how changing diets may stimulate demand for and trade of Mediterranean diet products. DESIGN: Literature review. Trends in global and US food consumption patterns are examined and trade data are reviewed to evaluate the impact of changing diets on trade of Mediterranean diet products. Market access issues are also addressed briefly to highlight the role of policy in the trade of Mediterranean diet products. RESULTS: Diets are shifting towards higher-value products such as meats, fruits and vegetables, and a wider array of packaged food products. Trade in these products has also grown in the past two decades, with several non-traditional importers and exporters becoming increasingly active in the global market. CONCLUSIONS: Income-driven demands for quality and variety are likely to increase the demand for Mediterranean diet products globally. While the middle-income countries appear to be the best growth prospects, the USA remains a potential growth market if these products can meet the growing consumer demand for variety, quality and convenience. Although consumer trends globally indicate growth in demand for Mediterranean diet products, the additional demand may not be reflected by a corresponding growth in trade. Trade in Mediterranean diet products continues to be hampered by higher than average trade barriers and high transportation costs for perishables. 相似文献
95.
96.
The present studies were conducted to isolate, select, identify and characterize gut bacteria as antimicrobial and growth promoting agent for the feed of economical y important ifsh Cirrhinus mrigala. ... 相似文献
97.
Rex A. Omonode Tony J. Vyn Doug R. Smith Pter Hegymegi Anita Gl 《Soil & Tillage Research》2007,95(1-2):182-195
Although the Midwestern United States is one of the world's major agricultural production areas, few studies have assessed the effects of the region's predominant tillage and rotation practices on greenhouse gas emissions from the soil surface. Our objectives were to (a) assess short-term chisel (CP) and moldboard plow (MP) effects on soil CO2 and CH4 fluxes relative to no-till (NT) and, (b) determine how tillage and rotation interactions affect seasonal gas emissions in continuous corn and corn–soybean rotations on a poorly drained Chalmers silty clay loam (Typic Endoaquoll) in Indiana. The field experiment itself began in 1975. Short-term gas emissions were measured immediately before, and at increasing hourly intervals following primary tillage in the fall of 2004, and after secondary tillage in the spring of 2005, for up to 168 h. To quantify treatment effects on seasonal emissions, gas fluxes were measured at weekly or biweekly intervals for up to 14 sampling dates in the growing season for corn. Both CO2 and CH4 emissions were significantly affected by tillage but not by rotation in the short-term following tillage, and by rotation during the growing season. Soil temperature and moisture conditions in the surface 10 cm were significantly related to CO2 emissions, although the proportion of variation explained by temperature and moisture was generally very low (never exceeded 27%) and varied with the tillage system being measured. In the short-term, CO2 emissions were significantly higher for CP than MP and NT. Similarly, mean seasonal CO2 emissions during the 2-year period were higher for CP (6.2 Mg CO2-C ha−1 year−1) than for MP (5.9 Mg CO2-C ha−1 year−1) and NT (5.7 Mg CO2-C ha−1 year−1). Both CP and MP resulted in low net CH4 uptake (7.6 and 2.4 kg CH4-C ha−1 year−1, respectively) while NT resulted in net emissions of 7.7 kg CH4-C ha−1 year−1. Mean emissions of CO2 were 16% higher from continuous corn than from rotation corn during the two growing seasons. After 3 decades of consistent tillage and crop rotation management for corn and soybean producing grain yields well above average in the Midwest, continuous NT production in the corn–soybean rotation was identified as the system with the least soil-derived C emissions to the atmosphere from among those evaluated prior to and during corn production. 相似文献
98.
Schernthaner A Lendl CE Hartmann K Pragst I Preissel AK Henke J 《Veterinary anaesthesia and analgesia》2011,38(5):439-450
ObjectiveTo evaluate the cardiorespiratory effects and plasma concentrations of medetomidine-midazolam-ketamine (MMK) combinations administered by intramuscular (IM) or subcutaneous (SC) injection in sable ferrets (Mustela putorius furo).Study designProspective randomized experimental study.AnimalsEighteen adult ferrets: weight median 1.19 (range 0.81–1.60) kg.MethodsAnimals were allocated to one of three groups: group IM07 received 20 μg kg?1 medetomidine, 0.5 mg kg?1 midazolam and 7 mg kg?1 ketamine IM; group IM10 20 μg kg?1 medetomidine, 0.5 mg kg?1 midazolam and 10 mg kg?1 ketamine IM; and group SC10 20 μg kg?1 medetomidine, 0.5 mg kg?1 midazolam and 10 mg kg?1 ketamine SC. Following instrumentation, cardiorespiratory parameters and plasma drug concentrations were measured every 5 minutes (T5–T30) for 30 minutes Ferrets were then euthanased. Data were analysed using anova for repeated measures. p < 0.05 was considered significant.ResultsResults are mean ± SD. Induction of anaesthesia (minutes) in IM07 and IM10 [2 (1)] was significantly faster than in SC10 [5 (2)]. All groups demonstrated the following: results given as groups IM07, IM10 and SC10 respectively. Mean arterial blood pressures (mmHg) were initially high [186 (13); 174 (33) and 174 (9) at T5] but decreased steadily. Pulse rates were initially 202 (20), 213 (17) and 207 (33) beats minute?1, decreasing with time. PaO2 (mmHg) was low [54.0 (8), 47.7 (10) and 38.5 (1)] at T5, although in groups IM07 and IM10 it increased over time. Plasma concentrations of all drugs were highest at T5 (36, 794 and 8264 nmol L?1 for medetomidine, midazolam and ketamine, respectively) and decreased thereafter: for both midazolam and ketamine, concentrations in IM07 and IM10 were higher than SC10.Conclusions and clinical relevanceMMK combinations containing either 7 or 10 mg kg?1 ketamine and given IM are suitable combinations for anaesthetising ferrets, although the observed degree of hypoxaemia indicates that oxygen administration is vital. 相似文献
99.
Michelotto PV Muehlmann LA Zanatta AL Bieberbach EW Kryczyk M Fernandes LC Nishiyama A 《Veterinary journal (London, England : 1997)》2011,190(2):e3-e6
This study investigated the putative roles of inflammation and platelet-activating factor (PAF) in exercise-induced pulmonary haemorrhage (EIPH). Two-year-old Thoroughbred colts (n=37) were exercised on a racetrack for 5months before commencement of the study. Each colt was then exercised at 15-16m/s over 800-1000m and broncho-alveolar lavage fluid (BALF) was collected 24h later. The colts were subsequently divided into two groups on the basis of BALF analysis; an EIPH-positive group (presence of haemosiderophages, n=23) and an EIPH-negative group (absence of haemosiderophages, n=14). BALF from the EIPH-positive group had a significantly higher protein concentration (0.39±0.28 vs. 0.19±0.12mg/mL, P=0.031), higher PAF bioactivity (0.18±0.12 vs. 0.043±0.05 340:380nm ratio, P=0.042) and a higher lipid hydroperoxide concentration compared to the EIPH-negative group. There was also a lower nitrite concentration and reduced production of superoxide anion and hydrogen peroxide by alveolar macrophages in the EIPH-positive group. There was evidence of pulmonary inflammation and a decreased innate immune response of alveolar macrophages in EIPH-positive colts compared with the EIPH-negative group. 相似文献
100.
Techniques for the production of raspberry long canes with high yield potential were studied on a research station and in two commercial nurseries in South Norway. Potted ‘Glen Ample’ plants were grown in the open and in polyethylene greenhouses during two seasons in order to optimize cultural practices. Dates of propagation and transfer to the production sites were varied. Following cold storage from December to early June, the canes were tipped (cut) at 160 cm height and grown in open plastic tunnels in the fruiting season for the evaluation of growth and yield performance. Remarkable berry yields of 1.5–3.8 kg per plant (cane) were regularly achieved. When grown in the open, later starts than June 1 (June 15 and July 1) successively reduced yields. On the other hand, an earlier start involves risks of growth cessation due to low spring temperature. When grown in greenhouses, high yields were still possible when plants were transferred from propagation conditions as late as July 1, although optimal yields of nearly 4 kg per plant were obtained with transfer on June 15. In a year with unusually high summer temperatures, the yields of canes produced in the open and in greenhouses did not vary significantly, whereas in the second year with normal summer temperatures, canes produced in greenhouses consistently out-yielded those produced in the open by about 1 kg per cane. Regression analyses revealed that high yields were associated with fruiting cane architecture traits such as cane height, number and length of laterals, and a low proportion of dormant buds. The single most important component was lateral length which alone accounted for 82% of the yield variation. Since lateral lengths increased from the shoot tip towards the base, cane heights in excess of 2 m are required for the attainment of top yields as the uppermost nodes with short and low-yielding laterals then can be eliminated by tipping. 相似文献