1,721,028 research outputs found
Isolation and characterization of an amphiphylic form of human intestinal aminopeptidase N.
No full textNew material from renewable resourses: Polysilicate-Lignin Composites
No full textNew material from renewable resourses: Polysilicate-Lignin Composites
Organic-Inorganic porous composite material (in nano or microscale) have been extensively studied in the last decade since they combined the advantages of the inorganic material (e.g. rigidity, thermal stability, inertiness) and the organic phase (e.g. ductility and therefore processability).
A defining feature of polymer composite, is that the dimension of the silica fillers () confers a dramatic increase in interfacial area, which induces intrinsic crosslinking in the bulk.
One of the most efficient procedure is colloidal sol-gel process in the presence of a preformed polymer or monomers with tailored morfologies (). Herein we describe the formation of a new ecocompatible insulating material adopting an hybrid procedure by using the lignosulfonate as it is or undergone to a basic treatement (NaOH or NH3) to provide partial depolymerisation.
The oligomers obtained upon neutralization can be dispersed in the silica colloidal mixture (by acid or basic catalysed treatement) and furtherly polymerised in situ by adding a controlled amount of opportune hydrophobising (starch-oil biopolymer) with expanding and pH-controlling reactants (ammoniumbicarbonate and oxalic acid) .
Globally the system is a totally biocompatible rigid foam composed mainly by blended biopolymer/mesoporous silica. The porous microcomposite material obtained shows promising requirements of low density and low conductivity, which can be adapt for insulating uses for costructions.
Nuovi materiali a matrice rinnovabile: La sfida di un pannello isolante a base di lignina e silice
Attraverso la formazione di aereogel di Silicio è possibile incapsulare una matrice di scarti dell’industria cartaria opportunamente modificata con addittivi biocompatibili, quali olio e amido di mais, al fine di ottenere un materiale composito coibentante che trova applicazione nel campo delle costruzioni. Il progetto si pone come obiettivo la formulazione di schiume rigide a matrice rinnovabile per pannelli isolanti o come materiali riempitivi. Il costituente principale è il lignosolfonato, prodotto di scarto dell’industria cartaria che viene inglobato in una matrice porosa di vetro modificata attraverso l’aggiunta di opportuni leganti, fibre di rinforzo e additivi idrofobici.
Le matrici possono essere utilizzate come:
1. Materiale riempitivo poroso e coibentante
2. Pannello contenitivo
Aerogel formed by TEOS hydrolysi
Calcium-, phospholipid-dependent protein kinase activity of cultured rat Sertoli cells and its modifications by vitamin A
No full textThe activity of the calcium-, phospholipid-dependent protein kinase (PKc) was partially characterized in Sertoli cell cultures prepared from 20-day-old rats. The calcium dependency, the requirements for phosphatidylserine and diolein, as well as the Km for ATP and for the tumor promoter TPA, were determined in total cell extracts. The specific activity of PKc was almost 3-fold higher in the soluble than in the particulate fraction of Sertoli cells. Treatment of cultured Sertoli cells with retinol inhibited, within 1 h of treatment, both the soluble and the particulate fraction-associated PKc activity, with an IC50 of 0.1 microM. Partial inhibition of PKc activity was obtained treating Sertoli cell cultures with FSH, while testosterone was ineffective. However, both FSH and testosterone potentiated the inhibitory effect of retinol. Less differentiated Sertoli cells, obtained from 8-day-old rats, displayed higher PKc activity and a pattern of subcellular distribution of the enzyme opposite to that of Sertoli cells obtained from 20-day-old rats. These data suggest that the actual PKc activity of rat Sertoli cells be negatively regulated by retinol and, spontaneously, during the progression of Sertoli cell differentiation
Surgical and radiological perspectives for the spinal accessory nerve passing through a fenestrated internal jugular vein: case series and literature review
No full textThe preservation of the spinal accessory nerve represents a key goal in head and neck oncologic surgery during selective neck dissection. This study aims to illustrate the anatomical variants of the XI cranial nerve, delving into the relationship between the spinal nerve and the internal jugular vein, as well as the surgical implications. Two cases of patients who underwent oncologic surgery with neck dissection are described. Both cases found the spinal accessory nerve passing through the fenestration of the internal jugular vein. Alongside this case series, an independent literature review was conducted using the Medline and PubMed databases. In the majority of cases (67% - 96%), the spinal accessory nerve traces a lateral course to the internal jugular vein. Less frequently, the XI cranial nerve courses medial to the internal jugular vein. More rarely, as described in this case series, the nerve crosses through the fenestration of the vein (0.48% - 3.3%)
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
[Extraction of fecal lipids and identification of hydroxystearic acid by gas chromatography-mass spectrometry (GC/MS)]
No full textFrom COVID-19 vaccine candidates to compulsory vaccination: The attitudes of Italian citizens in the key 7-month of vaccination campaign
Full text linkIntroduction: The aim of the study is to understand the evolution of COVID-19 vaccine acceptance over the key 7-month vaccine campaign in Italy, a period in which the country moved from candidate vaccines to products administered to the public. The research focus points to evaluate COVID-19 vaccine attitudes in adults and their children, propension towards compulsory vaccination, past and present adherence to anti-flu and anti-pneumococcal vaccines, and the reasons for trust/mistrust of vaccines. Methods: Italian residents aged 16->65 years were invited to complete an online survey from September 2020 to April 2021. The survey contained 13 questions: 3 on demographic data; 8 on vaccine attitudes; and 2 open-ended questions about the reasons of vaccine confidence/refusal. A preliminary word frequency analysis has been conducted, as well as a statistical bivariate analysis. Results: Of 21.537 participants, the confidence of those in favor of the COVID-19 vaccine increases of 50 % and the number of people who wanted more information decreases by two-third. Willingness to vaccinate their children against COVID-19 also increased from 51 % to 66.5 %. Only one-third of the strong vaccine-hesitant participants, i.e. 10 %, remained hostile. Compulsory vaccination showed a large and increasing favor by participants up to 78 %, in a way similar to their propensity for children's mandatory vaccination (70.6 %). Respondents’ past and present adherence to anti-flu and anti-pneumococcal vaccines does not predict their intentions to vaccinate against COVID-19. Finally, a semantic analysis of the reasons of acceptance/refusal of COVID-19 vaccination suggests a complex decision-making process revealed by the participants’ use of common words in pro-and-cons arguments. Conclusion: The heterogeneity in the COVID-19 vaccine hesitancy, determinants and opinions detected at different ages, genders and pandemic phases suggests that health authorities should avoid one-size-fits-all vaccination campaigns. The results emphasize the long-term importance of reinforcing vaccine information, communication and education needs
Assignment of the five disulfide bridges in an alpha-amylase inhibitor from wheat kernel by fast-atom-bombardment mass spectrometry and Edman degradation.
No full textThe assignment of the five disulfide bridges in an alpha-amylase monomeric inhibitor from wheat kernel (coded 0.28) was achieved by combining fast-atom-bombardment mass spectrometry (FAB-MS) and automatic sequencing based on Edman degradation. Direct FAB-MS analysis of the native and reduced enzymatic digests of the protein allowed the assignment of three disulfide bridges out of five, including those involving two adjacent cysteine residues. The remaining two disulfide bridges were assigned by sequencing automatically the peptide clusters purified from the tryptic digest of the native protein
- …
