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51.
Essential oil (EO) from aerial parts (leaves, juvenile branches, and flowers when present) of Pistacia lentiscus L. growing wild in five localities of Sardinia (Italy) was extracted by steam-distillation (SD) and analyzed by gas chromatography (GC), FID, and GC-ion trap mass spectrometry (ITMS). Samples of P. lentiscus L. were harvested between April and October to study the seasonal chemical variability of the EO. A total of 45 compounds accounting for 97.5-98.4% of the total EO were identified, and the major compounds were alpha-pinene (14.8-22.6%), beta-myrcene (1-19.4%), p-cymene (1.6-16.2%), and terpinen-4-ol (14.2-28.3%). The yields of EO (v/dry w) ranged between 0.09 and 0.32%. Similar content of the major compounds was found in samples from different origins and seasonal variability was also observed. The EOs were tested for their antifungal activity against Aspergillus flavus, Rhizoctonia solani, Penicillium commune, Fusarium oxysporum. Two samples were weakly effective against Aspergillus flavus. Furthermore, terpinenol and alpha-terpineol, two of the major components of EO of Pistacia lentiscus L., totally inhibited the mycelian growth of A. flavus. Quite good antioxidant activity of the EO was also found.  相似文献   
52.
Human norovirus (NoV) is reportedly the major cause of non-bacterial gastroenteritis outbreaks worldwide and is commonly associated with water- and food-borne transmission via the faecal-oral route. Aside from humans, norovirus has been detected in pigs, cattle and mice. The close relatedness of some human and animal noroviruses has raised concerns about potential zoonotic transmission. Our laboratory recently reported the development of a multiplex real-time RT-PCR for the detection and genotyping of norovirus of genogroups I-III. Here we report a study of 56 faecal specimens from pigs and sheep that were collected and screened for noroviruses using this assay. Norovirus was found in 2/23 (9%) of porcine specimens (all were genogroup II) and in 8/33 (24%) of ovine specimens (all were genogroup III). Samples tested positive for norovirus were verified by conventional RT-PCR with different primer sets. Genomes of representative porcine and ovine norovirus strains underwent partial sequence analysis (343 and 2045 bases, respectively). This is the first report describing norovirus in sheep.  相似文献   
53.
Strigolactones, phytohormones with diverse signaling activities, have a common structure consisting of two lactones connected by an enol-ether bridge. Strigolactones derive from carotenoids via a pathway involving the carotenoid cleavage dioxygenases 7 and 8 (CCD7 and CCD8) and the iron-binding protein D27. We show that D27 is a β-carotene isomerase that converts all-trans-β-carotene into 9-cis-β-carotene, which is cleaved by CCD7 into a 9-cis-configured aldehyde. CCD8 incorporates three oxygens into 9-cis-β-apo-10'-carotenal and performs molecular rearrangement, linking carotenoids with strigolactones and producing carlactone, a compound with strigolactone-like biological activities. Knowledge of the structure of carlactone will be crucial for understanding the biology of strigolactones and may have applications in combating parasitic weeds.  相似文献   
54.
The volumetric ring and the computerized tomography (CT) techniques were applied to study soil bulk density, in order to understand the compaction of an Albaqualf soil (Planosol) of the Rio Grande do Sul State, Southern Brazil (latitude 31°52′00″S and Longitude 52°21′24″W). Among six different tillage systems and crop rotations the greatest soil bulk density was measured for the continuous irrigated rice crop system and the lowest for the no-tillage treatment under rye grass straw. The CT method enabled the measurement of bulk density variations in the soil profile and indicated critical zones not observed by the volumetric ring method that measures only the mean sample soil bulk densities. A meaningful correlation between soil bulk densities measured by both methods was found, although the CT method presented more reliable results in comparison to the volumetric ring method. A 3% variation in bulk density was observed due to method intrinsic errors, probably also correlated to different samples sizes.  相似文献   
55.
In 1997, the National Wildlife Institute, in co-operation with the University of Turin, produced an action plan to eradicate the American grey squirrel from Italy, as this introduced species replaces the native red squirrel through competitive exclusion and damages trees through de-barking. The first step, a trial eradication of a small population of grey squirrels at Racconigi (Turin) to evaluate the efficiency of the removal techniques, started in May 1997. Preliminary results showed that eradication was feasible, but the project was opposed by radical animal rights groups which took the National Wildlife Institute to court in June 1997. This legal action caused a suspension of the project and led to a lengthy judicial enquiry that ended in July 2000 with the acquittal of the Institute. Nevertheless, the 3-year suspension of all actions led to a significant expansion of the grey squirrel's range and thus eradication is no longer considered practical. Therefore, in the medium to long term, grey squirrels are likely to expand through continental Eurasia. This constitutes a major threat to the survival of the red squirrel over a large portion of its distribution range and will have a significant impact on forests, with economic damage to timber crops.  相似文献   
56.
Previous work demonstrated that a commercial formulation of piperonyl butoxide (PBO) did inhibit the activity of some plant proteolytic enzymes. In this paper, the effect of pure PBO and nine pure PBO homologues (PBOH) appropriately synthesized toward bromelain and papain was studied in hydrocarbon solution using the bis(2-ethylhexyl)sodium sulfosuccinate (AOT) reverse micellar system. This study establishes that the majority of these compounds show, in vitro, interesting protease inhibition activities. The benzodioxole and dihydrobenzofuran structures, in particular, 5-[2-(2-butoxyethoxy)ethoxymethyl]-benzo[1,3]dioxole (EN 1-40) and 6-[2-(2-butoxyethoxy)ethoxymethyl]-5-propyl-2,3-dihydrobenzofuran (EN 16-5), respectively, appear to be responsible for protease inhibition. Measures of octanol/water partition coefficients on PBO and PBOH have demonstrated that water solubility plays a fundamental role in the expression of protease inhibition activity.  相似文献   
57.
The chemical composition of the essential oil of the Sardinian Rosmarinus officinalis L. obtained by hydro distillation and steam\hydro distillation was studied using GC-FID and MS. Samples were collected at different latitude and longitude of Sardinia (Italy). The yields ranged between 1.75 and 0.48% (v/w, volume/dry-weight). A total of 30 components were identified. The major compounds in the essential oil were alpha-pinene, borneol, (-) camphene, camphor, verbenone, and bornyl-acetate. Multivariate analysis carried out on chemical molecular markers, with the appraisal of chemical, pedological, and random amplified polymorphic DNA data, allows four different clusters to be distinguished. The antimicrobial and antifungal tests showed a weak activity of Sardinian rosemary. On the other hand, an inductive effect on fungal growth, especially toward Fusarium graminearum was observed.  相似文献   
58.
The study of fog water chemical composition and the contribution of fog droplets to total chemical deposition has become a relevant environmental subject over the past few years. This paper describes a fog water collector suitable for deposition network operation, due to its complete automation and to the facility of remote acquisition of sampling information. Sampling of fog droplets on teflon strings is activated by an optical fog detector according to a particular protocol operated by a microprocessor controller. Multiple sample collection, also microprocessor controlled, is possible with this instrument. The problem of fog droplet sampling in sub-freezing conditions is overcome using a sampling schedule implemented by the microprocessor controller which alternates between sampling periods and stand-by periods during which melting of the rime collected on the strings is allowed. Field tests on the reliability and reproducibility of the sampling operations are presented in the paper. Side by side operation of the fog collector with a PVM-100 fog liquid water content meter shows that the amount of water per unit volume of air collected by the sampling instrument is proportional to the fog liquid water content averaged over the period of an entire fog event.  相似文献   
59.
Macrophages are fundamental cells of the innate immune system, which, through phagocytosis and nitric oxide production, eliminate pathogens. The aim of the present study was to determine if macrophages from chicken families divergently selected to high and low antibodies response differ in nitric oxide production and phagocytic capacity. Blood monocytes derived macrophages were activated with lipopolysaccharide and supernatant from chicken spleen lymphocytes cultured with Concanavalin A (containing chicken interferon). Nitric oxide production was evaluated in culture supernatants. Phagocytic capacity of activated and non-activated macrophages was assayed using yeasts and IgY opsonized sheep red blood cells. Activated and non-activated macrophages from the high antibodies response family produced higher nitric oxide levels, internalized more yeast and significantly more opsonized sheep red blood cells than macrophages from the low antibodies response family. Moreover, activated macrophages became more elongated and widely spread. These findings indicate that macrophages from the high antibodies response family were more active suggesting that the differences in antibody response also depend on macrophage function.  相似文献   
60.
The ORF50/Rta gene has been shown to be an essential gene for many gammaherpesviruses. Although the BoHV-4 ORF50/Rta homolog, immediate early gene 2 (IE2), has been shown to activate several BoHV-4 early and late promoters in cotransfection assays, there is no direct proof of its indispensability for progression of the virus to the lytic replication cycle in the context of the viral genome. In the present communication, replication defective BoHV-4-V.test IE2 mutants were efficiently rescued, with respect to production of infectious virus and DNA replication, upon the expression of BoHV-4 ORF50/Rta in trans. Surprisingly, in the course of our studies, we discovered that the IE2 gene is duplicated in the genome of BoHV-4-U.  相似文献   
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