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排序方式: 共有154条查询结果,搜索用时 15 毫秒
1.
Yang Shilei Hao Qian Wang Hailong Van Zwieten Lukas Yu Changxun Liu Taoze Yang Xiaomin Zhang Xiaodong Song Zhaoliang 《Journal of Soils and Sediments》2020,20(4):1811-1823
Journal of Soils and Sediments - Phytolith-occluded carbon (PhytOC) is mainly derived from the products of photosynthesis, which can be preserved in soils and sediments for hundreds-to-thousands of... 相似文献
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Vladimír Jekl Karel Hauptman Edita Jeklová Gerry M Dorrestein Zdenek Knotek 《Veterinary Clinics of North America: Exotic Animal Practice》2006,9(3):695-700
A desexed female ferret was presented with bilateral alopecic changes. Clinical examination revealed generalized alopecia and abdominal distension. A polycystic mass was found behind the right kidney, and the whole abdomen was filled with a large turgid mass. Radiography and ultrasonography confirmed the presumptive diagnosis of a hydrometra. Hematology and serum biochemistry showed regenerative anemia with light azotemia. Laparotomy showed the presence of a neoplastic mass at the location of the right ovary, a massive enlargement of the uterus filled with a clear fluid, and a subcapsular cyst on the left kidney. After surgery, histopathologic examination of the tissues diagnosed a leiomyoma of the right ovary with hyperplasia of the uterine wall. 相似文献
4.
The annual dynamics of fish assemblage in a pond-connecting canal of a South Moravian pond aquaculture facility was studied
to reveal potential assemblage effects on pond stocks and vice versa. The species richness of fish assemblage and seasonal
dynamics of its development were predominantly dependent upon the fish stock of the interconnected ponds (particularly due
to escapees during the period of pond harvesting), which contributed to a considerable increase of commercial fish species
occurrence. Using a seasonal parameter, the season proved to have a major impact on fish assemblage dynamics (r = −0.71, P < 0.001). Spring samples were dominated by commercial fishes of aquaculture origin (mainly Cyprinus carpio). Occurrence of several fish species originating from the wild (bleak, Alburnus alburnus, chub, Leuciscus cephalus and roach, Rutilus rutilus) was also reported.
The pond canal was found to be an important reservoir site of persistent survival and potential subsequent spreading of some
undesirable alien fishes such as topmouth gudgeon (Pseudorasbora parva) and gibel carp (Carrasius auratus). Moreover, more attention should be paid to the potential negative impacts of all fishes of aquaculture origin upon the
natural ecosystem and to the adverse effects due to the immigration of wild fish into aquaculture pond farming units. 相似文献
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Hellal F Hurtado A Ruschel J Flynn KC Laskowski CJ Umlauf M Kapitein LC Strikis D Lemmon V Bixby J Hoogenraad CC Bradke F 《Science (New York, N.Y.)》2011,331(6019):928-931
Hypertrophic scarring and poor intrinsic axon growth capacity constitute major obstacles for spinal cord repair. These processes are tightly regulated by microtubule dynamics. Here, moderate microtubule stabilization decreased scar formation after spinal cord injury in rodents through various cellular mechanisms, including dampening of transforming growth factor-β signaling. It prevented accumulation of chondroitin sulfate proteoglycans and rendered the lesion site permissive for axon regeneration of growth-competent sensory neurons. Microtubule stabilization also promoted growth of central nervous system axons of the Raphe-spinal tract and led to functional improvement. Thus, microtubule stabilization reduces fibrotic scarring and enhances the capacity of axons to grow. 相似文献
7.
Shi T Simanova E Schönherr J Schreiber L 《Journal of agricultural and food chemistry》2005,53(6):2207-2212
Effects of diethyl suberate (DESU), diethyl sebacate (DES), dibutyl suberate (DBSU), dibutyl sebacate (DBS), and tributyl phosphate (TBP) on diffusion of 14C-2,4-dichlorophenoxy butyric acid (2,4-DB) across cuticular membranes (CM) was studied. Astomatous CM were isolated enzymatically from Stephanotis floribunda Brongn. leaves, and diffusion was measured at 20 degrees C. The alkyl-substituted dicarboxylic acids constitute a homologous series with carbon numbers increasing from C12 to C18. Molecular weights increased only moderately from 230.0 (DESU) to 314.5 (DBS), while partition coefficients varied over orders of magnitude from 92 (DESU), to 1213 (DES), to 15,988 (DBSU), to 210,762 (DBS). All the above compounds turned out to be accelerators as they increased 2,4-DB mobility by up to 40-fold with accelerator concentrations in the CM ranging from only 9.2 to 105 g kg(-1). Efficacy (2,4-DB mobility in the presence/mobility in the absence of accelerators) increased with increasing concentrations of accelerators in CM or in reconstituted cuticular waxes. Plotting efficacy vs accelerator concentration in the CM resulted in straight lines, and their slopes increased in the order DBS (0.14), DBSU (0.31), DES (0.51), and DESU (0.85). Hence, DESU was the most powerful accelerator in this series as it increased 2,4-DB mobility in the CM about 6 times more than DBSU. Waxes constitute the major barrier in plant cuticles, and plots of efficacy vs accelerator concentration in Stephanotis wax were also linear, but compared to CM slopes were steeper by factors of 3.20 (DBS), 2.97 (DBSU), 2.70 (DES), and 1.62 (DESU). TBP was similarly effective as DESU, but plots of efficacy vs concentration were not linear, and curves approached a plateau at 60-80 g kg(-1). These data are discussed with regard to suitability of these accelerators for formulating systemic pesticides. 相似文献
8.
Rudolf I Golovchenko M Sikutová S Rudenko N Grubhoffer L Hubálek Z 《Folia parasitologica》2005,52(3):274-276
A total of 350 nymphs of the common tick Ixodes ricinus (Linnaeus, 1758) were collected in an endemic focus of Lyme borreliosis (South Moravia, Czech Republic) and examined for the presence of the protozoan Babesia microti (Fran?a, 1909) by polymerase chain reaction (PCR), using primers specific for the B. microti gene encoding small subunit rRNA. The assay revealed five positive pools (out of 70 pools examined); the corresponding prevalence rate was about 1.5%. Sequence analysis of the PCR products confirmed their 100% homology with that of B. microti. The study represents the first evidence of B. microti in ixodid ticks in the Czech Republic. 相似文献
9.
The positive relationship between fecal CP concentration and diet OM digestibility in cattle, which is based on increasing undigested microbial CP and decreasing fecal OM as OM digestibility increases, may be used as an indirect method for estimating diet OM digestibility from fecal CP concentration. Results of digestibility trials (445 individual observations) conducted at Hohenheim and Braunschweig, Germany, and at Gumpenstein, Austria, were used to study the relationship between CP concentration in feces (x, g/kg OM) and OM digestibility (y, %). The best fit was obtained with the curvilinear relationship y = ai -107.7e(-0.01515 x x), with a1 = 79.76 and a2 = 72.86 (R2 = 0.82; residual SD = 2.7; SE = 0.13), which takes into account the effects of location (i = 1 for Braunschweig and Hohenheim, and i = 2 for Gumpenstein). Dietary CP and crude fat concentration, and DMI had no effect on fecal CP content, whereas crude fiber content, proportion of concentrate in the diet, and forage type significantly affected CP concentration in feces; however, the magnitude of these effects was less than 2 percentage units, and the direction of the effect of proportion of concentrate in the diet was not uniform. The curvilinear relationship between fecal CP concentration (observed range, 100 to 300 g/kg of OM) and diet OM digestibility (observed range = 57 to 80%) may be used to estimate diet OM digestibility, particularly for field trials, as it requires no feed samples and does not physically restrict the animal. 相似文献
10.
Kraemer C Nikseresht N Piatek JO Tsyrulin N Dalla Piazza B Kiefer K Klemke B Rosenbaum TF Aeppli G Gannarelli C Prokes K Podlesnyak A Strässle T Keller L Zaharko O Krämer KW Rønnow HM 《Science (New York, N.Y.)》2012,336(6087):1416-1419
Magnetism has been predicted to occur in systems in which dipolar interactions dominate exchange. We present neutron scattering, specific heat, and magnetic susceptibility data for LiErF(4), establishing it as a model dipolar-coupled antiferromagnet with planar spin-anisotropy and a quantum phase transition in applied field H(c|| = 4.0 ± 0.1 kilo-oersteds. We discovered non-mean-field critical scaling for the classical phase transition at the antiferromagnetic transition temperature that is consistent with the two-dimensional XY/h(4) universality class; in accord with this, the quantum phase transition at H(c) exhibits three-dimensional classical behavior. The effective dimensional reduction may be a consequence of the intrinsic frustrated nature of the dipolar interaction, which strengthens the role of fluctuations. 相似文献