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1.

The Mediterranean evergreen vegetation of Sicily, comprised in the belt of the Quercetea ilicis, occupies a large part of the island. Human intervention (cutting, fire, pasture) has brought about a degradation of the natural vegetation. This study is based on our phytosociological research of the Quercetea ilicis belt on Sicily.

With the ‘habitat comparison’ method, the dynamical relations between the different vegetation units have been defined.

We distinguish the following stages, with reference to their vegetation structure:

  • a herbaceous stage formed by steppic vegetation, preceded by various types of nitrophilous-ruderal vegetation on abandoned fields;

  • a garrigue stage dominated by half-shrubs;

  • a macquis stage with various distinct plant communities, four communities being important in regressive successions, and three in progressive ones;

  • a woodland and shrub-woodland stage with three different substages: pre-existent forests, present woodlands, and woodlands which tend towards the final, stable stage of vegetation (potential natural vegetation).

The dynamic relationships both in progressive and regressive successions have been synthesized in a scheme. In this scheme we have shown the main stages of the vegetation in their dynamics and we have constructed different series of vegetation types in two altitudinal belts, which are determined by varying environmental conditions of today.

The results also show that in some cases the progressive series follow different pathways than the regressive series, and the final stage of the progressive series is different from the original vegetation.

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2.
A haloalkaliphilic, thermophilic Bacillus strain (T14), isolated from a shallow hydrothermal vent of Panarea Island (Italy), produced a new exopolysaccharide (EPS). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain T14 was highly related (99 % similarity) to Bacillus licheniformis DSM 13T and Bacillus sonorensis DSM 13779T. Further DNA–DNA hybridization analysis revealed 79.40 % similarity with B. licheniformis DSM 13T and 39.12 % with B. sonorensis DSM 13779T. Sucrose (5 %) was the most efficient carbon source for growth and EPS production. The highest EPS production (366 mg l?1) was yielded in fermenter culture at 300 rpm after 48 h of incubation. The purified fraction EPS1 contained fructose/fucose/glucose/galactosamine/mannose in a relative proportion of 1.0:0.75:0.28:tr:tr and possessed a molecular weight of 1,000 kDa displaying a trisaccharide unit constituted by sugars with a β-manno-pyranosidic configuration. Screening for biological activity showed anti-cytotoxic effect of EPS1 against Avarol in brine shrimp test, indicating a potential use in the development of novel drugs.  相似文献   
3.
AIMS: In order to identify 73 thermophilic isolates from shallow, marine thermal vents of Eolian Islands, we compared their restriction patterns of amplified 16S rDNA with those of nine well described Bacillus species and eight Eolian Bacillus strains. METHODS AND RESULTS: This study allowed to assign 57 (78%) isolates to different Bacillus species. Nineteen field strains were recognised as representatives of four described species, namely B. thermodenitrificans, "B. caldolyticus", B. vulcani and B. stearothermophilus. The profiles of 38 isolates matched instead, those of seven Eolian strains (B. thermodenitrificans strain A2, B. licheniformis strain B3-15, and five novel species, represented by Bacillus strain 1bw, Bacillus strain 4-1, Bacillus strain 5-2, Bacillus strain 10-1, Bacillus strain 1as). Among the 16 unidentified isolates, seven restriction patterns were recognised. CONCLUSIONS: This study showed that restriction analysis of amplified 16S rDNA is useful for a rapid and reliable identification of strains belonging to described species as well as for recognition of new species. SIGNIFICANCE AND IMPACT OF THE STUDY: This work revealed a high taxonomic diversity among the thermophilic bacilli isolated from Eolian Islands and a distinct distribution of the species within the Eolian hydrothermal vent system.  相似文献   
4.
Recent studies have shown that the chromatographic separation of mixtures of monosaccharides and disaccharides may be improved by employing Y zeolites, a procedure which holds promise in the separation of oligosaccharides. In the present study, a column packed with zeolite was employed to study the separation of fructooligosaccharides (FOS). FOS were produced by an enzyme isolated from Rhodotorula sp., which produces GF2 (kestose), GF3 (nystose) and GF4 (frutofuranosyl nystose). The identification and quantification of the sugars were carried out by ion exchange chromatography with pulsed amperometric detection (HPAEC-PAD). The separation of fructooligosaccharides was carried out using a fixed bed column packed with Ba2+-exchange Y zeolites. The effects of temperature (40–50 °C), injected volume per bed volume (2.55–7.64%), superficial velocity (0.1–0.15 cm min−1) and eluent composition (40–60% ethanol) were investigated using a fractionary factorial design with separation efficiency as the response. The results showed that the most favorable conditions for the separation of the oligosaccharide–glucose mixture were 60% ethanol as eluent, temperature of 50 °C, superficial velocity of 0.1 cm min−1 and 2.55% injection volume per bed volume of injection mixture, using two columns in series. The values for separation efficiency were 0.60 for oligosaccharide–glucose, 1.00 for oligosaccharide–fructose, 0.22 for oligosaccharide–sucrose, 0.43 for glucose–fructose, 0.82 for glucose–sucrose and 1.23 for fructose–sucrose.  相似文献   
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The purpose of this study was to improve the stability of cloricromene (AD6) in ophthalmic formulations and its drug availability at the ocular level. To this end, AD6-loaded polymeric nanoparticle suspensions were made using inert polymer resins (Eudragit RS100 and RL100). We modified the quasi-emulsion solvent diffusion technique by varying some formulation parameters (the drug-to-polymer ratio, the total drug and polymer amount, and the stirring speed). The chemical stability of AD6 in the nanosuspensions was assessed by preparing some formulations using (unbuffered) isotonic saline or a pH 7 phosphate buffer solution as the dispersing medium. The formulations were stored at 4°C, and the rate of degradation of AD6 was followed by high performance liquid chromatography (HPLC). The obtained nanosuspensions showed mean sizes and a positive surface charge (ζ-potential) that make them suitable for an ophthalmic application; these properties were maintained upon storage at 4°C for several months. In vitro dissolution tests confirmed a modified release of the drug from the polymer matrixes. Nanosuspensions prepared with saline solution and no or lower amounts of surfactant (Tween 80) showed an enhanced stability of the ester drug for several months, with respect to an AD6 aqueous solution. Based on the tecnological results, AD6-loaded Eudragit Retard nanoparticle suspensions appear to, offer promise as a means to improving the shelf life and bioavailability of this drug after ophthalmic application. Published: March 24, 2006  相似文献   
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8.
To report the results of the DECT trial, a phase II study of locally advanced or operable HER2‐positive breast cancer (BC) treated with taxanes and concurrent anthracyclines and trastuzumab. Eligible patients (stage IIA‐IIIB HER2‐positive BC, 18–75 years, normal organ functions, ECOG ≤1, and left ventricular ejection fraction (LVEF) ≥55%) received four cycles of neoadjuvant docetaxel, 100 mg/m2 intravenously, plus trastuzumab 6 mg/kg (loading dose 8 mg/kg) every 3 weeks, followed by four 3‐weekly cycles of epirubicin 120 mg/m2 and cyclophosphamide, 600 mg/m2, plus trastuzumab. Primary objective was pathologic complete response (pCR) rate, defined as ypT0/is ypN0 at definitive surgery. We enrolled 45 consecutive patients. All but six patients (13.3%) completed chemotherapy and all underwent surgery. pCR was observed in 28 patients (62.2%) overall and in 6 (66.7%) from the inflammatory subgroup. The classification and regression tree analysis showed a 100% pCR rate in patients with BMI ≥25 and with hormone negative disease. The median follow up was 46 months (8–78). Four‐year recurrence‐free survival was 74.7% (95%CI, 58.2–91.2). Seven patients (15.6%) recurred and one died. Treatment was well tolerated, with limiting toxicity being neutropenia. No clinical cardiotoxicity was observed. Six patients (13.4%) showed a transient LVEF decrease (<10%). In one patient we observed a ≥10% asymptomatic LVEF decrease persisting after surgery. Notwithstanding their limited applicability due to the current guidelines, our findings support the efficacy of the regimen of interest in the neoadjuvant setting along with a fairly acceptable toxicity profile, including cardiotoxicity. Results on BMI may invite further assessment in future studies. J. Cell. Physiol. 231: 2541–2547, 2016. © 2016 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals, Inc.  相似文献   
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10.
Applied Microbiology and Biotechnology - Herpes simplex virus type 1 (HSV-1) is responsible of common and widespread viral infections in humans through the world, and of rare, but extremely severe,...  相似文献   
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