171 research outputs found
La sostenibilità ambientale dei porti turistici italiani: un’analisi della comunicazione web
No full textL’impatto che i porti turistici possono avere sull’ambiente costiero e marino ha stimolato l’attivazione di iniziative che cercano di ridurre i potenziali rischi, anche in ragione della crescente sensibilità dei turisti rispetto alle tematiche green. A livello internazionale, sono già presenti studi sulla sostenibilità e le certificazioni ambientali di porti commerciali e crocieristici e altri di natura più tecnica legati all’inquinamento e alla contaminazione. Tuttavia, nonostante la sua rilevanza, non sono disponibili ricerche sulla comunicazione via web delle politiche intraprese dai singoli porti turistici per la tutela e la promozione ambientale. Questo studio si propone di contribuire a colmare il gap presente in letteratura esaminando i siti web di 93 porti turistici italiani ed evidenziando, per ciascuno, il ruolo ricoperto dalle tematiche green nella struttura del sito e nei contenuti. I risultati mostrano una scarsa attenzione rispetto ai temi della sostenibilità ambientale, a cui si suppone corrisponda un’adozione altrettanto limitata di pratiche green. Fanno tuttavia eccezione alcuni porti turistici italiani che si propongono come best practice nella comunicazione green attraverso il
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Dehydro-dermorphins. III. Circular dichroism investigation of conformation in solution
No full textDehydropeptide analogs of dermorphin (H-Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2) and N-terminal fragments containing one or two dehydrophenylalanine residues in the 3rd and/or 5th position, have been investigated by means of CD spectroscopy. The results indicate that the above dehydropeptides can adopt different conformations in alcohol and water solutions. In methanol and trifluoroethanol, the CD spectra are mainly consistent with the presence of folded structures, probably stabilized by intramolecular hydrogen bonds. In water, conversely, CD data indicate disruption of ordered structures and formation of preferentially extended flexible conformations. Models of the involved folded structures are tentatively proposed, taking into account the geometric features of dehydro residues and their tendency to favor hydrogen-bonded 10-membered rings
Optically active polymers bearing side-chain photochromic moieties: synthesis and chiroptical properties of methacrylic homopolymers with pendant trans-azobenzene chromophores bound through L-leucine, L-valine and L-proline amino acid spacers
No full textFull Paper: Novel optically active monomers, based on different L-amino acid residues such as trans-(S)-4-(2-methacryloylamino-3-methylbutanoylamino)azobenzene, trans-(S)-4-(2-methacryloylamino-4-methylpentanoylamino)azobenzene and trans-(S)-4-(N-methacryloyl-2-pyrrolidinoylamino)azobenzene, have been prepared and homopolymerized by free radical initiation. Circular dichroism spectra of the resulting polymers, as compared with those of the corresponding low molecular weight analogues, purposely synthesized, allow one to suggest that the macromolecules assume in solution achiral or chiral conformations with a prevailing screw sense, depending on the bulkiness and rigidity of the L-amino acid residue present in the side chains. The role of intra- and/or intermolecular hydrogen bonding between side-chain amido groups along the backbone and the structural requirements of the chiral groups in determining the macromolecular arrangement is also discussed
Analisi numerica dell’impatto di miscele granulari su ostacoli fissi.
No full textNella presente comunicazione si illustrano i risultati di analisi numeriche volte alla simulazione dell’impatto di miscele granulari sature contro ostacoli fissi attraverso l’utilizzo di un codice di calcolo basato sul Metodo degli Elementi Discreti. Il confronto di tali risultati con quelli derivanti da una sperimentazione su modello fisico condotta da ricercatori dell’Università di Pavia evidenzia la necessità di ricorrere, nelle analisi numeriche, a modelli costitutivi in grado di portare in conto la viscosità del materiale utilizzato nella sperimentazione
Preoperative doxorubicin plus ifosfamide in primary soft-tissue sarcomas of the extremities
No full textA total of 51 patients with large, primary, high-grade soft-tissue sarcomas of the extremities were treated at our institute with two preoperative and three postoperative cycles of doxorubicin plus ifosfamide/mesna. Preoperative doxorubicin was given intra-arterially for lesions of the lower extremities. Of 47 evaluable patients, 22 (47%) showed clinical responses and 21 (45%), pathologic responses. Clinical and pathologic responses, however, were not necessarily coincident in the same patient. Conservative limb-sparing surgery was performed in 41 cases (87%), and in 4 cases amputation was avoided as a result of the local improvement induced by chemotherapy. Local recurrence occurred in 12 cases (25%), 3 of which required further amputation. Although the follow-up period was only 28 months, the 4-year actuarial survival was 91% and the 4-year metastasis-free value was 69%. An evident difference existed between patients who showed a documented clinical response to chemotherapy and those who did not, the 4-year metastasis-free value being 85% and 59% (P = 0.1), respectively. Adjuvant preoperative chemotherapy may allow for limb-salvage surgical procedures in selected cases
Double versus single stapling technique in rectal anastomosis
No full textA retrospective analysis to compare the single vs double stapled technique for rectal anastomosis was carried out on patients that underwent radical surgical resection between January 1986 and January 1989 at the Istituto Nazionale Tumori of Milan. In 143 patients anastomotic integrity had been checked both intraoperatively with air insufflation and postoperatively by water soluble contrast enema. A single stapled anastomosis (SST) was performed using the EEA instrument in 94 patients, and in 49 patients a double stapled (DST) using the EEA and TA instruments was performed. The level of the anastomosis was less than or equal to 10 cm from the anal margin in 94 patients (54 SST, 40 DST). In 52 patients it was greater than 10 cm (40 SST, 12 DST) (SST vs DST ns). The presence of anastomotic dehiscence occurred in 29 (20%) patients (17 SST, 12 DST). This was not related either to the anastomotic site or to the suture technique used. The dehiscence was located on the posterior wall in 79% of cases and in 58% the size was less than 1 cm. In 78% clinical symptoms were evident. There was no difference between SST and DST patients. Further surgery (colostomy) was necessary in six patients (2 SST, 4 DST). Two patients died through complications (1 SST, 1 DST); making an overall mortality rate of 1.0% and 2.0% in each group. There was no difference in infection rate and length of postoperative stay in the two groups. Our data demonstrate that both methods give similar results
Photoresponsive Polypeptides: Photochromism and Conformation of Poly(l-Glutamic Acid), Containing Spiropyran Units
No full textSpirobenzopyran units were bound to the side chains of poly (L-glutamic acid) and partially methylated poly(L-glutamate)s. The modified polymers were found to exhibit ''reverse photochromism'' in hexafluoro-2-propanol (HFP), so the samples kept in the dark were characterized by an intense absorption band in the visible range of the spectrum, which was completely erased upon exposure to sunlight or irradiation at 500-550 nm.
The CD spectra showed that the macromolecules adopted a random coil conformation in the dark, whereas the bleached solutions after exposure to light displayed the typical CD pattern of the alpha-helix. The back reaction in the dark was accompanied by the progressive decrease of the helix content and recovery of the original disordered conformation. The photoinduced conformational changes resulted in large and reversible viscosity variations.
When spiropyran side chains were converted to ''spiropyran salts'' of trifluoroacetic acid, the system was still photochromic, but the macromolecules were disordered both in the dark and light conditions. However, when appropriate amounts of methanol were added as a cosolvent to the HFP solutions, the system responded to light, giving reversible variations of the alpha-helix content. Irradiation at appropriate solvent compositions allowed modulation of the extent of the photoresponse
[A surgical emergency: iatrogenic lesion of the spleen. Case report and review of the literature].
No full textSplenectomy is very frequently used to manage splenic lesions. Nevertheless, spleen-injured patients who have undergone splenectomy are exposed to hyposplenism. Authors report two patients with splenic lesions treated by conservative surgery (with fibrin glue) using the videolaparoscopic method. In both cases the preservation of the spleen was achieved. The conservative treatment allows one to avoid the risk of hyposplenism and provides the possibility to treat the patient with minimal surgical stress
Efficacy of octreotide in the prevention of pancreatic fistula after elective pancreatic resections: a prospective, controlled, randomized clinical trial
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