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1.
J Chem Phys ; 152(23): 234504, 2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32571054

RESUMO

The protic ionic liquid diethylmethylammonium methanesulfonate ([DEMA][OMs]) was analyzed in depth by differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, and broadband dielectric spectroscopy (BDS) under anhydrous conditions. Karl Fischer titration, NMR, and FT-IR spectra confirmed the high purity of [DEMA][OMs]. The melting point (37.7 °C) and the freezing point (14.0 °C) obtained by DSC agree well with the values determined by BDS (40.0 °C and 14.0 °C). The dc conductivity (σdc) above the melting/freezing point obeys the Vogel-Fulcher-Tammann (VFT) equation well, and thus, the proton conduction in [DEMA][OMs] is assumed to be dominated by the vehicle mechanism. In contrast, the σdc below the melting/freezing point can be fitted by the Arrhenius equation separately, and therefore, the proton conduction is most likely governed by the proton hopping mechanism. The non-negligible influence of previously reported low water content on the physicochemical properties of [DEMA][OMs] is found, indicating the importance of reducing water content as much as possible for the study of "intrinsic" properties of protic ionic liquids.

2.
ACS Appl Mater Interfaces ; 12(16): 18258-18272, 2020 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-32223273

RESUMO

Cell-material interactions are crucial for many biomedical applications, including medical implants, tissue engineering, and biosensors. For implants, while the adhesion of eukaryotic host cells is desirable, bacterial adhesion often leads to infections. Surface free energy (SFE) is an important parameter that controls short- and long-term eukaryotic and prokaryotic cell adhesion. Understanding its effect at a fundamental level is essential for designing materials that minimize bacterial adhesion. Most cell adhesion studies for implants have focused on correlating surface wettability with mammalian cell adhesion and are restricted to short-term time scales. In this work, we used quartz crystal microbalance with dissipation monitoring (QCM-D) and electrical impedance analysis to characterize the adhesion and detachment of S. cerevisiae and E. coli, serving as model eukaryotic and prokaryotic cells within extended time scales. Measurements were performed on surfaces displaying different surface energies (Au, SiO2, and silanized SiO2). Our results demonstrate that tuning the surface free energy of materials is a useful strategy for selectively promoting eukaryotic cell adhesion and preventing bacterial adhesion. Specifically, we show that under flow and steady-state conditions and within time scales up to ∼10 h, a high SFE, especially its polar component, enhances S. cerevisiae adhesion and hinders E. coli adhesion. In the long term, however, both cells tend to detach, but less detachment occurs on surfaces with a high dispersive SFE contribution. The conclusions on S. cerevisiae are also valid for a second eukaryotic cell type, being the human embryonic kidney (HEK) cells on which we performed the same analysis for comparison. Furthermore, each cell adhesion phase is associated with unique cytoskeletal viscoelastic states, which are cell-type-specific and surface free energy-dependent and provide insights into the underlying adhesion mechanisms.


Assuntos
Adesão Celular/fisiologia , Técnicas de Microbalança de Cristal de Quartzo/métodos , Citoesqueleto/química , Citoesqueleto/fisiologia , Elasticidade/fisiologia , Entropia , Escherichia coli/química , Escherichia coli/fisiologia , Células HEK293 , Humanos , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/fisiologia , Dióxido de Silício/química , Dióxido de Silício/metabolismo , Viscosidade
3.
Rev Sci Instrum ; 90(12): 125106, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31893814

RESUMO

Water plays a key role in the functioning of natural and synthetic molecular systems. Despite several hydration studies, different techniques are employed individually for monitoring different physical features such as kinetics, dynamics, and absorption. This study describes a compact hydration cell that enables simultaneous dielectric relaxation spectroscopy (DRS) and mass loss/uptake measurements in thin organic layers under controlled humidity conditions and in a wide temperature range. This approach enabled us to correlate the physical quantities obtained during the same experiment by complementary techniques. To demonstrate the performance of this device, a 200 nm thick poly(methyl methacrylate) (PMMA) layer was measured at various relative humidity levels (0%-75%), temperatures (25-75 °C), and frequencies (DRS: 0.1 Hz-1 MHz) to study how hydration and dehydration processes affect its molecular dynamics. The results show the capability of this setup to study the changes in the PMMA film regarding the kinetics and molecular dynamics upon variation of the water content.

4.
Environ Sci Pollut Res Int ; 25(28): 28725-28729, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30109688

RESUMO

Using Fourier transform infrared spectroscopy (FT-IR) measurements and comparing the spectrum peaks (range 4000-600 cm-1) with reference spectra database and instrument libraries, we observed new evidence of the ingestion of microplastic particles analyzing the digestive tracts of Talitrus saltator. Specimens, sampled in central Italy, probably ingested the particles with natural detritus. Since worldwide many species of invertebrates and vertebrates (e.g., birds) feed on Amphipoda along coastal ecosystems, we hypothesized that microplastic in these crustaceans can be accumulated along the food chain.


Assuntos
Anfípodes/química , Exposição Dietética/análise , Plásticos/análise , Poluentes Químicos da Água/análise , Animais , Ecossistema , Ecotoxicologia/métodos , Monitoramento Ambiental/métodos , Cadeia Alimentar , Conteúdo Gastrointestinal , Itália , Polietileno/análise , Espectroscopia de Infravermelho com Transformada de Fourier
5.
Environ Pollut ; 229: 1032-1036, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28778793

RESUMO

The ability of Posidonia oceanica spheroids (egagropiles, EG) to incorporate plastics was investigated along the central Italy coast. Plastics were found in the 52.84% of the egagropiles collected (n = 685). The more represented size of plastics has range within 1-1.5 cm, comparable to the size of natural fibres. Comparing plastics occurring both in EG and in surrounding sand, Polyethylene, Polyester and Nylon were the most abundant polymers in EG, while PSE, PE, PP and PET were the most represented in sand. In particular PE and PP were significantly more represented in sand, while PE, Nylon, Polyester and microfibers (as pills) were more represented in EG. Within plastics found in EG, 26.9% were microfibers as small pills (<1 cm), mainly composed of polyamide, polyester, cotton and PET mixing. These microfibers might be produced by discharges from washing machines and currently represents an emerging pollutant with widespread distribution in marine and freshwater ecosystems.


Assuntos
Alismatales/química , Monitoramento Ambiental , Plásticos/análise , Poluentes Químicos da Água/análise , Ecossistema , Itália , Polietileno/análise , Polímeros/análise
6.
Immunotherapy ; 6(8): 945-52, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25313572

RESUMO

Celiac disease (CD) is a gluten-induced immune-mediated disorder that has been associated with a defective response to the hepatitis B virus (HBV) vaccination. This unresponsiveness could lead to a world health problem, because non-responder patients could represent a reservoir of HBV-susceptible people that will persist as healthy carriers, leading to the diffusion of the disease. This article presents a literature review of both intramuscular (IM) and intradermal (ID) routes for boosters in celiac patients. We used PubMed database and generated the odds ratio (OR) of the response on the basis of electronic searches of clinical trials. Although our results confirm the positive response of celiac patients to IM vaccination, the ID route seems to be better than the conventional one, since it could provide a saving in cost and a greater immunogenicity.


Assuntos
Doença Celíaca/imunologia , Vacinas contra Hepatite B/administração & dosagem , Vacinação/métodos , Humanos , Injeções Intradérmicas , Injeções Intramusculares , Vacinação/normas
7.
World J Gastroenterol ; 20(30): 10383-94, 2014 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-25132754

RESUMO

Vaccination is the main prophylactic measure to reduce the mortality caused by hepatitis B virus (HBV) infection in healthy subjects since the immune response to hepatitis B recombinant vaccination occurs in over 90% of general population. Individuals who develop an anti-HBs titer less than 10 mIU/mL after primary vaccination cycle are defined "no responders". Many factors could cause a non response to the HBV vaccination, such as administration of the vaccine in buttocks, impaired vaccine storage conditions, drug abuse, smoking, infections and obesity. Moreover there are some diseases, like chronic kidney disease, human immunodeficiency virus infection, chronic liver disease, celiac disease, thalassaemia, type I diabetes mellitus, down's syndrome and other forms of mental retardation that are characterized by a poorer response to HBV vaccination than healthy subjects. To date it is still unclear how to treat this group of patients at high risk of hepatitis B infection. Recent studies seem to indicate that the administration of HBV recombinant vaccine by the intradermal route is very effective and could represent a more useful strategy than intramuscular route. This review focuses on the use of anti hepatitis B vaccine by intradermal route as alternative to conventional intramuscular vaccine in all non responder patients. A comprehensive review of the literature using PubMed database, with appropriate terms, was undertaken for articles in English published since 1983. The literature search was undertaken in September 2013.


Assuntos
Anticorpos Anti-Hepatite B/sangue , Vacinas contra Hepatite B/administração & dosagem , Hepatite B/prevenção & controle , Vacinação , Biomarcadores/sangue , Hepatite B/imunologia , Hepatite B/virologia , Vacinas contra Hepatite B/imunologia , Humanos , Injeções Intradérmicas , Injeções Intramusculares , Falha de Tratamento , Vacinas Sintéticas/administração & dosagem
8.
World J Clin Cases ; 2(1): 16-9, 2014 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-24527428

RESUMO

Gullo's syndrome is a newly identified condition characterized by a chronic elevation of pancreatic amylase and/or lipase in the absence of pancreatic disease. Until now, only one case of benign isolated hyperlipasemia in children has been recorded. We describe two children with benign and not familial increase of serum lipase. Case 1: a six year old girl presented with occasional discovery of serum lipase elevation. Medical history was silent for pancreatic hyperenzymemia. The screening for possible causes for elevated lipase (genetic, autoimmune and infectious diseases) was normal. The serum lipase increased three fold over the upper limit (193 U/L; reference range 0-60 U/L), with daily fluctuation of values. Both ultrasound scan and magnetic resonance imaging were normal. The genetic mutation associated with chronic pancreatitis was negative. We followed up this patient for two years with blood tests every six months and she did not show any signs or symptoms of pancreatic disease, except for the high level of lipase serum. Case 2: an eight year old girl complained of nausea, vomiting and severe abdominal pain in the epigastric region after eating for the last two weeks. Full blood count, electrolytes, C-reactive protein, liver and renal function were normal. Serum lipase was 96 U/L (reference range 0-60 U/L). The screening for the possible causes of pancreatic disease was negative. Endoscopy of the upper gastrointestinal tract, ultrasound, computed tomography scan and magnetic resonance imaging were normal. One year after the presentation of the symptoms, the patient became asymptomatic although the level of serum lipase continued to be high.

9.
Hepat Mon ; 13(8): e11215, 2013 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-24171010

RESUMO

CONTEXT: Cystic fibrosis (CF) is the most widespread autosomal recessive genetic disorder that limits life expectation amongst the Caucasian population. As the median survival has increased related to early multidisciplinary intervention, other manifestations of CF have emerged especially for the broad spectrum of hepatobiliary involvement. The present study reviews the existing literature on liver disease in cystic fibrosis and describes the key issues for an adequate clinical evaluation and management of patients, with a focus on the pathogenetic, clinical and diagnostic-therapeutic aspects of liver disease in CF. EVIDENCE ACQUISITION: A literature search of electronic databases was undertaken for relevant studies published from 1990 about liver disease in cystic fibrosis. The databases searched were: EMBASE, PubMed and Cochrane Library. RESULTS: CF is due to mutations in the gene on chromosome 7 that encodes an amino acidic polypeptide named CFTR (cystic fibrosis transmembrane regulator). The hepatic manifestations include particular changes referring to the basic CFTR defect, iatrogenic lesions or consequences of the multisystem disease. Even though hepatobiliary disease is the most common non-pulmonary cause of mortality in CF (the third after pulmonary disease and transplant complications), only about the 33%of CF patients presents clinically significant hepatobiliary disease. CONCLUSIONS: Liver disease will have a growing impact on survival and quality of life of cystic fibrosis patients because a longer life expectancy and for this it is important its early recognition and a correct clinical management aimed at delaying the onset of complications. This review could represent an opportunity to encourage researchers to better investigate genotype-phenotype correlation associated with the development of cystic fibrosis liver disease, especially for non-CFTR genetic polymorphisms, and detect predisposed individuals. Therapeutic trials are needed to find strategies of fibrosis prevention and to avoid its progression prior to development its related complications.

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