Detection and quantitation of resveratrol in tomato fruit (Lycopersicon esculentum Mill.)     

Ragab AS  Van Fleet J  Jankowski B  Park JH  Bobzin SC 《Journal of agricultural and food chemistry》2006,54(19):7175-7179

Resveratrol is a stilbene phytoalexin well-known for its presence in grape, wine, and peanut. As a result of its antioxidant and chemopreventative properties, it has gained much attention as a functional food ingredient. A gas chromatography-mass spectrometry method for the detection of resveratrol, its 3-glucopyranoside piceid, and the cis isomers of both compounds has been developed and used to quantitate the levels of these compounds in the skin of commercially available tomato fruit (Lycopersicon esculentum Mill.). The resveratrol concentration remains relatively stable during fruit maturation, reaching a maximum concentration in the skin of 18.4 +/- 1.6 microg/g dry weight at 4 weeks postbreaker. No stilbenes were detected in the flesh of tomato fruit.  相似文献   

Colloid transport of plutonium in the far-field of the Mayak Production Association, Russia     

Novikov AP  Kalmykov SN  Utsunomiya S  Ewing RC  Horreard F  Merkulov A  Clark SB  Tkachev VV  Myasoedov BF 《Science (New York, N.Y.)》2006,314(5799):638-641

Sorption of actinides, particularly plutonium, onto submicrometer-sized colloids increases their mobility, but these plutonium colloids are difficult to detect in the far-field. We identified actinides on colloids in the groundwater from the Mayak Production Association, Urals, Russia; at the source, the plutonium activity is approximately 1000 becquerels per liter. Plutonium activities are still 0.16 becquerels per liter at a distance of 3 kilometers, where 70 to 90 mole percent of the plutonium is sorbed onto colloids, confirming that colloids are responsible for the long-distance transport of plutonium. Nano-secondary ion mass spectrometry elemental maps reveal that amorphous iron oxide colloids adsorb Pu(IV) hydroxides or carbonates along with uranium carbonates.  相似文献   

Immunological reversal of autoimmune diabetes without hematopoietic replacement of beta cells     

Suri A  Calderon B  Esparza TJ  Frederick K  Bittner P  Unanue ER 《Science (New York, N.Y.)》2006,311(5768):1778-1780

Type 1 diabetes mellitus results from the autoimmune destruction of the beta cells of the pancreatic islets of Langerhans and is recapitulated in the nonobese diabetic strain of mice. In an attempt to rescue islet loss, diabetic mice were made normoglycemic by islet transplantation and immunization with Freund's complete adjuvant along with multiple injections of allogeneic male splenocytes. This treatment allowed for survival of transplanted islets and recovery of endogenous beta cell function in a proportion of mice, but with no evidence for allogeneic splenocyte-derived differentiation of new islet beta cells. Control of the autoimmune disease at a crucial time in diabetogenesis can result in recovery of beta cell function.  相似文献   

Platelet-derived serotonin mediates liver regeneration     

Lesurtel M  Graf R  Aleil B  Walther DJ  Tian Y  Jochum W  Gachet C  Bader M  Clavien PA 《Science (New York, N.Y.)》2006,312(5770):104-107

The liver can regenerate its volume after major tissue loss. In a mouse model of liver regeneration, thrombocytopenia, or impaired platelet activity resulted in the failure to initiate cellular proliferation in the liver. Platelets are major carriers of serotonin in the blood. In thrombocytopenic mice, a serotonin agonist reconstituted liver proliferation. The expression of 5-HT2A and 2B subtype serotonin receptors in the liver increased after hepatectomy. Antagonists of 5-HT2A and 2B receptors inhibited liver regeneration. Liver regeneration was also blunted in mice lacking tryptophan hydroxylase 1, which is the rate-limiting enzyme for the synthesis of peripheral serotonin. This failure of regeneration was rescued by reloading serotonin-free platelets with a serotonin precursor molecule. These results suggest that platelet-derived serotonin is involved in the initiation of liver regeneration.  相似文献   

Murine leukemia induced by retroviral gene marking     

Li Z  Düllmann J  Schiedlmeier B  Schmidt M  von Kalle C  Meyer J  Forster M  Stocking C  Wahlers A  Frank O  Ostertag W  Kühlcke K  Eckert HG  Fehse B  Baum C 《Science (New York, N.Y.)》2002,296(5567):497

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Is Bedout an impact crater? Take 2     

Renne PR  Melosh HJ  Farley KA  Reimold WU  Koeberl C  Rampino MR  Kelly SP  Ivanov BA 《Science (New York, N.Y.)》2004,306(5696):610-2; author reply 610-2

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Oxidant effects on forest tree seedling growth in the Appalachian mountains     

Stephen F. Duchelle  J. M. Skelly  Boris I. Chevone 《Water, air, and soil pollution》1982,18(1-3):363-373

Long range transport of episodic concentrations of O₃ into the Appalachian Mountains of Virginia was recorded in the summer season of 1979 and 1980. Continuous monitoring of O₃ indicated monthly averages of ? 0.05 ppm O₃ and several periods averaged ? 0.08 ppm O₃. Open-top chambers were used to test the effect of ambient doses of the pollutant on the growth of 8 planted forest tree species native to the area. Height growth was suppressed for all species at the end of the second growing season when grown in open plots (no chamber) and ambient chambers compared to those grown in charcoal-filtered air supplied chambers. Height growth trends of open < ambient chamber < filtered air chamber were consistent. Virginia pine and green ash were significantly taller (p=0.10) when grown within filtered air chambers. Tulip poplar and green ash manifested purple stippling on the adaxial leaf surface and sweetgum developed purple coloration under open or ambient chamber conditions; other species exhibited no visible injury.  相似文献   

Multilocus sequence typing of Pseudomonas syringae sensu lato confirms previously described genomospecies and permits rapid identification of P. syringae pv. coriandricola and P. syringae pv. apii causing bacterial leaf spot on parsley     

Bull CT  Clarke CR  Cai R  Vinatzer BA  Jardini TM  Koike ST 《Phytopathology》2011,101(7):847-858

Since 2002, severe leaf spotting on parsley (Petroselinum crispum) has occurred in Monterey County, CA. Either of two different pathovars of Pseudomonas syringae sensu lato were isolated from diseased leaves from eight distinct outbreaks and once from the same outbreak. Fragment analysis of DNA amplified between repetitive sequence polymerase chain reaction; 16S rDNA sequence analysis; and biochemical, physiological, and host range tests identified the pathogens as Pseudomonas syringae pv. apii and P. syringae pv. coriandricola. Koch's postulates were completed for the isolates from parsley, and host range tests with parsley isolates and pathotype strains demonstrated that P. syringae pv. apii and P. syringae pv. coriandricola cause leaf spot diseases on parsley, celery, and coriander or cilantro. In a multilocus sequence typing (MLST) approach, four housekeeping gene fragments were sequenced from 10 strains isolated from parsley and 56 pathotype strains of P. syringae. Allele sequences were uploaded to the Plant-Associated Microbes Database and a phylogenetic tree was built based on concatenated sequences. Tree topology directly corresponded to P. syringae genomospecies and P. syringae pv. apii was allocated appropriately to genomospecies 3. This is the first demonstration that MLST can accurately allocate new pathogens directly to P. syringae sensu lato genomospecies. According to MLST, P. syringae pv. coriandricola is a member of genomospecies 9, P. cannabina. In a blind test, both P. syringae pv. coriandricola and P. syringae pv. apii isolates from parsley were correctly identified to pathovar. In both cases, MLST described diversity within each pathovar that was previously unknown.  相似文献   

Sporadic autonomic dysregulation and death associated with excessive serotonin autoinhibition   总被引：1，自引：0，他引：1  

Audero E  Coppi E  Mlinar B  Rossetti T  Caprioli A  Banchaabouchi MA  Corradetti R  Gross C 《Science (New York, N.Y.)》2008,321(5885):130-133

Sudden infant death syndrome is the leading cause of death in the postneonatal period in developed countries. Postmortem studies show alterations in serotonin neurons in the brainstem of such infants. However, the mechanism by which altered serotonin homeostasis might cause sudden death is unknown. We investigated the consequences of altering the autoinhibitory capacity of serotonin neurons with the reversible overexpression of serotonin 1A autoreceptors in transgenic mice. Overexpressing mice exhibited sporadic bradycardia and hypothermia that occurred during a limited developmental period and frequently progressed to death. Moreover, overexpressing mice failed to activate autonomic target organs in response to environmental challenges. These findings show that excessive serotonin autoinhibition is a risk factor for catastrophic autonomic dysregulation and provide a mechanism for a role of altered serotonin homeostasis in sudden infant death syndrome.  相似文献   

Phenotypic Correlations of Stride Traits and Body Measurements in Lipizzaner Stallions and Mares     

Mirjana Baban  Ino Curik  Boris Antunovic  Mato Cacic  Nidal Korabi  Pero Mijic 《Journal of Equine Veterinary Science》2009

Besides being well known for their use in classical dressage, Lipizzaner horses are today becoming more and more popular for use in driving sport, with Croatia as the largest breeder in the world. To estimate their phenotypic predisposition for driving sport, this research analyzes the correlation between body measurements and traits of length and speed of walk and hand-led trot in 18 stallions (LS) and 53 mares (LM) by using a digital camera. Statistical analysis of the data concerning phenotypic correlations among the indicated traits has revealed the potential of documenting a large number of structural exterior body characteristics and quantitative measurements in Lipizzaner horses, and technical equipment has been found to be useful in research of stride traits. Higher withers height (WH) achieved through breeding was found to be negatively correlated with the number of strides per second during walk and trot, but positively correlated with walk stride length, especially in LS. Higher values for chest girth (CG) and cannon bone circumference (CBC) were found to be positively correlated with speed, as well as with stride length in LS, and negatively correlated with the number of strides per second during walk and trot in both LS and LM. Because for many years the goal of breeding Lipizzaners in Croatia has been to obtain a bigger body format and longer stride, leading to better results in a driving sport, these findings confirm breeding goals in selection work guided toward better stride length and extended stride as the most desirable traits for driving sport.  相似文献