Metabolism of ¹⁴c-labeled plant materials by woodlice (Tracheoniscus rathkei brandt) and soil microorganisms     

V.G. Reyes  J.M. Tiedje 《Soil biology & biochemistry》1976,8(2):103-108

¹⁴C-Labeled cottonwood leaves, wheat stems and leaves were fed to woodlice supported on an inert surface or to woodlice on soil containing the natural soil microbial population. Degradation of the plant materials was more rapid and complete for the soil animal—soil microorganism combination than for each separately. The rate of degradation was inversely related to fiber content of plant substrate. The presence of the soil microorganisms was more important for the mineralization of the more fibrous wheat than for the more easily melabolizable cottonwood. The faeces obtained from cottonwood fed woodlice contained little readily available substrate for soil microorganisms but were mineralized at a rather constant rate of 1.5% per day. The hemicellulose containing fraction of the plant was readily metabolized by the woodlice while the ligno-cellulose fraction was not. Antibiotics in the diet did not affect metabolism of the hemicellulose-ligno-cellulose fraction or of previously assimilated label, however, they did limit metabolism of the unfractionated substrate. It is suggested that the gut microbiota competes for readily digestible substrates and does not significantly aid in the digestion of the more resistant plant constituents. The pattern of the total respiration correlated well with the pattern of ¹⁴CO₂ respiration following periodic feeding of ¹⁴C-labeled substrate.  相似文献   

为何国内市场E0级木地板踪影难寻？     

享耳 《国际木业》2007,37(1):29-29

很长一段时间内，在国内木地板市场上，主要是强化木地板产品，只要是质量上上点档次、品牌影响较为稳定一些的，几乎都声称自己是“E0”级。一时间“本产品已经达到欧美发达国家E0级产品水平”、“本产品甲醛释放量为0”、“本产品属木地板系列最高等级——E0”等等耀人眼目的字眼跃然各强化木地板产品的柜台上、广告里或包装中。当大家都在喊“本老王的瓜最甜”之时，广大消费者倒是如堕十里云雾之中，搞不明白，为何都声称自己的产品是“E0”级，咋就少见有“E1”、“E2”级产品呢？  相似文献   

Amoebicidal and giardicidal compounds from the leaves of Zanthoxylum liebmannianun     

Arrieta J  Reyes B  Calzada F  Cedillo-Rivera R  Navarrete A 《Fitoterapia》2001,72(3):295-297

The crude ethanol extract from the leaves of Zanthoxylum liebmannianum exhibited inhibitory effect on the reproduction of trophozoites of Entamoeba histolytica (IC(50)=3.48 microg/ml) and Giardia lamblia (IC(50)=58.00 microg/ml). From this extract, asarinin, hyperin, beta-sitosterol, and beta-sitosterol glucoside were isolated. Among them, asarinin was the most active with IC(50) values of 19.86 microg/ml for E. histolytica and 35.45 microg/ml for G. lamblia. The remaining compounds showed moderate activity against both parasites.  相似文献   

Variable very-high-energy gamma-ray emission from the microquasar LS I +61 303     

Albert J  Aliu E  Anderhub H  Antoranz P  Armada A  Asensio M  Baixeras C  Barrio JA  Bartelt M  Bartko H  Bastieri D  Bavikadi SR  Bednarek W  Berger K  Bigongiari C  Biland A  Bisesi E  Bock RK  Bordas P  Bosch-Ramon V  Bretz T  Britvitch I  Camara M  Carmona E  Chilingarian A  Ciprini S  Coarasa JA  Commichau S  Contreras JL  Cortina J  Curtef V  Danielyan V  Dazzi F  De Angelis A  de Los Reyes R  De Lotto B  Domingo-Santamaría E  Dorner D  Doro M  Errando M  Fagiolini M  Ferenc D  Fernández E  Firpo R  Flix J  Fonseca MV  Font L 《Science (New York, N.Y.)》2006,312(5781):1771-1773

Microquasars are binary star systems with relativistic radio-emitting jets. They are potential sources of cosmic rays and can be used to elucidate the physics of relativistic jets. We report the detection of variable gamma-ray emission above 100 gigaelectron volts from the microquasar LS I 61 + 303. Six orbital cycles were recorded. Several detections occur at a similar orbital phase, which suggests that the emission is periodic. The strongest gamma-ray emission is not observed when the two stars are closest to one another, implying a strong orbital modulation of the emission or absorption processes.  相似文献   

Fortification of milk with calcium: effect on calcium bioavailability and interactions with iron and zinc     

Perales S  Barberá R  Lagarda MJ  Farré R 《Journal of agricultural and food chemistry》2006,54(13):4901-4906

Calcium solubility, dialysability, and transport and uptake (retention + transport) by Caco-2 cells as indicators of calcium bioavailability have been estimated in the in vitro gastrointestinal digests of milk and calcium fortified milk. A significant linear correlation (p < 0.05) was obtained between calcium uptake and the amount of soluble calcium added to the cells, and also between percentage calcium uptake and the calcium measured in the analyzed samples. The solubility, dialysis, transport, and uptake values are higher (p < 0.05) for calcium fortified milks than for nonfortified milks; that is, calcium fortification increases not only calcium content but also its bioavailability. An inhibitory effect of calcium from fortified milks upon iron absorption was found. The observed effect of calcium from fortified milks upon zinc bioavailability depends on the in vitro method used, zinc solubility and dialysis decrease in calcium fortified milks, and percentage zinc uptake remains unchanged.  相似文献   

Bulk milk urea concentrations and their relationship with cow fertility in grazing dairy herds in southern Chile   总被引：2，自引：0，他引：2  

Wittwer FG  Gallardo P  Reyes J  Optiz H 《Preventive veterinary medicine》1999,38(2-3):159-166

Milk urea determination is being used as a broad indicator of protein/energy imbalance in dairy herds. The main purpose of this study was to compare blood and bulk milk urea values in grazing herds, to evaluate their seasonal variation under South Chilean conditions, and to examine their potential relationships with herd fertility. The association between herd blood urea concentration (mean of seven lactating cows) and bulk milk urea concentration (tank containing milk from the previous 24 h) was determined in 21 diary herds. Reference values, seasonal and herd variance, and the frequency of herds with values outside a range of 2.5 to 7.3 mmol/l were determined in bulk milk samples obtained monthly for a period of one year from 82 suppliers at two creameries located in southern Chile. Finally, bulk milk urea was measured every two weeks in samples from 24 herds, and the first service conception rate (FSCR) from 2153 dairy cows was determined. Mean bulk urea concentration was highly correlated with mean herd blood urea concentration (r = 0.95; p < 0.01). Mean urea concentration in the bulk milk samples obtained during one year from 82 herds was 4.9 +/- 1.2 mmol/l, with a range of 1.5 to 11.6 mmol/l. The highest values were found during spring and the lowest values during the summer. There was a high seasonal variation (CV = 13-47%) and between-herd variation (CV = 20-31%). Out of a total of 984 samples, 5.4% had urea values > 7.3 mmol/l and 3.8% had values < 2.5 mmol/l. Of the 82 herds, 27% had values outside the reference interval (2.5-7.3 mmol/l) on two or more occasions. FSCR was lower in herds when the bulk milk urea was > 7.3 mmol/l (50.7%) than in cows, where the urea concentration was < 5.0 mmol/l (73.8%) at the time of insemination. The study concluded that bulk milk urea concentrations provided information similar to herd blood urea concentrations in local grazing dairy herds. There was a high frequency of herds with abnormal values, with large variations between herds and between seasons. Increased milk urea concentrations during spring were associated with lower conception rates.  相似文献   

Interactions between commensal fungi and the C-type lectin receptor Dectin-1 influence colitis     

Iliev ID  Funari VA  Taylor KD  Nguyen Q  Reyes CN  Strom SP  Brown J  Becker CA  Fleshner PR  Dubinsky M  Rotter JI  Wang HL  McGovern DP  Brown GD  Underhill DM 《Science (New York, N.Y.)》2012,336(6086):1314-1317

The intestinal microflora, typically equated with bacteria, influences diseases such as obesity and inflammatory bowel disease. Here, we show that the mammalian gut contains a rich fungal community that interacts with the immune system through the innate immune receptor Dectin-1. Mice lacking Dectin-1 exhibited increased susceptibility to chemically induced colitis, which was the result of altered responses to indigenous fungi. In humans, we identified a polymorphism in the gene for Dectin-1 (CLEC7A) that is strongly linked to a severe form of ulcerative colitis. Together, our findings reveal a eukaryotic fungal community in the gut (the "mycobiome") that coexists with bacteria and substantially expands the repertoire of organisms interacting with the intestinal immune system to influence health and disease.  相似文献   

Genotypic variation for root architecture traits in seedlings of maize (Zea mays L.) inbred lines     

Bharath Kumar  Adel H. Abdel‐Ghani  Jenaro Reyes‐Matamoros  Frank Hochholdinger  Thomas Lübberstedt 《Plant Breeding》2012,131(4):465-478

  相似文献   

牛环形泰勒虫病二温式PCR诊断方法的建立及初步应用     

王振宝  刘启生  哈森  何晓杰  刘绪斌  孟茹  叶尔保勒  巴音查汗 《动物医学进展》2012,33(5):59-63

为建立特异、敏感、快速的二温式PCR诊断方法,根据牛环形泰勒虫裂殖子表面抗原(tams1)基因,设计了一对特异性引物,扩增出大小为154bp基因片段,经克隆、测序分析,与已知基因序列的相似性为96%。用建立的牛环形泰勒虫病二温式PCR诊断方法,对从新疆牛环形泰勒虫病流行地区采集的50份全血样品进行诊断,阳性率为88%,而血涂片检出的阳性率只有58%。经试验验证,该方法具有特异性高、敏感性强、重复性和稳定性好等优点。表明本试验所建立的二温式PCR诊断方法可用于牛环形泰勒虫病的临床诊断、隐性感染检测和流行病学调查。  相似文献   

Ultrastructural Study of the Canine Zona Pellucida Surface During In Vitro Maturation     

M De los Reyes  J Hetz  J Palomino 《Reproduction in domestic animals》2009,44(S2):247-250

The aim of the present study was to compare the ultrastructure of the surface of the zona pellucida (ZP) of immature and in vitro matured dog oocytes using scanning electron microscopy (SEM). Bitch oocytes were collected after ovariohysterectomy; the ovaries were sliced and the released cumulus–oocyte complexes (COCs) were washed with phosphate buffered saline (PBS). The selected COCs were randomly allocated into three groups, two groups were processed after in vitro maturation at both 72 and 96 h and a third group was processed immediately at immature state in PBS medium. After that, oocytes were fixed, critical point dried and viewed by using SEM. The diameters of the outer holes of the ZP were measured on a total of 93 oocytes; the results were analyzed with anova . The mean diameters of holes were different between groups (p < 0.05): 0.69 ± 0.12, 1.56 ± 0.19 and 1.42 ± 0.27 μm, for immature and in vitro matured oocytes for 72 and 96 h, respectively. The difference in the hole sizes between immature and in vitro matured canine oocytes indicates that the ZP surface is related to oocyte maturity in canines.  相似文献