Anisotropy and NMR spectroscopy

Abstract In this paper, different aspects concerning anisotropy in Nuclear Magnetic Resonance (NMR) spectroscopy have been reviewed. In particular, the relevant theory has been presented, showing how anisotropy stems from the dependence of internal nuclear spin interactions on the molecular orientation with respect to the external magnetic field direction. The consequences of anisotropy in the use of NMR spectroscopy have been critically discussed: on one side, the availability of very detailed structural and dynamic information, and on the other side, the loss of spectral resolution. The experiments used to measure the anisotropic properties in solid and soft materials, where, in contrast to liquids, such properties are not averaged out by the molecular tumbling, have been described. Such experiments can be based either on static low-resolution techniques or on one- and two-dimensional pulse sequences exploiting Magic Angle Spinning (MAS). Examples of applications of NMR spectroscopy have been shown, which exploit anisotropy to obtain important physico-chemical information on several categories of systems, including pharmaceuticals, inorganic materials, polymers, liquid crystals, and self-assembling amphiphiles in water. Solid-state NMR spectroscopy can be considered, nowadays, one of the most powerful characterization techniques for all kinds of solid, either amorphous or crystalline, and semi-solid systems for the obtainment of both structural and dynamic properties on a molecular and supra-molecular scale. Graphic abstrac

Natural history of patients with non cirrhotic portal hypertension: Comparison with patients with compensated cirrhosis

Background. The knowledge of natural history of patients with portal hypertension (PH) not due to cirrhosis is less well known than that of cirrhotic patients. Aim. To describe the clinical presentation and the outcomes of 89 patients with non-cirrhotic PH (25 with non-cirrhotic portal hypertension, INCPH, and 64 with chronic portal vein thrombosis, PVT) in comparison with 77 patients with Child A cirrhosis. Methods. The patients were submitted to a standardized clinical, laboratory, ultrasonographic and endoscopic follow-up. Variceal progression, incidence of variceal bleeding, portal vein thrombosis, ascites and survival were recorded. Results. At presentation, the prevalence of varices, variceal bleeding and ascites was similar in the 3 groups. During follow-up, the rate of progression to varices at risk of bleeding (p<0.0001) and the incidence of first variceal bleeding (p=0.02) were significantly higher in non-cirrhotic then in cirrhotic patients. A PVT developed in 32% of INCPH patients and in 18% of cirrhotics (p=0.02). Conclusions. In the patients with non–cirrhotic PH variceal progression is more rapid and bleeding more frequent than in cirrhotics. Patients with INCPH are particularly prompt to develop PVT. This observational study suggests that the management of patients with non-cirrhotic PH should take into consideration the natural history of portal hypertension in these patients and cannot be simply derived by the observation of cirrhotic patients

Evaluation of Glucose Uptake in Normal and Cancer Cell Lines by Positron Emission Tomography.

To date, there is no definitive demonstration of the utility of positron emission tomography (PET) in studying glucose metabolism in cultured cell lines. Thus, this study was designed to compare PET to more standardized methods for the quantitative assessment of glucose uptake in nontransformed and transformed living cells and to validate PET for metabolic studies in vitro. Human colon and breast carcinoma cell lines and mouse embryo fibroblasts were evaluated for [ 18 F]fluorodeoxyglucose ([ 18 F]FDG) uptake by PET and autoradiography and 2-deoxyglucose (2-DG) incorporation by colorimetric assay and analyzed for the radiotoxic effects of [ 18 F]FDG and the expression levels of glucose transporters. Indeed, [ 18 F]FDG incorporation on PET was comparable to [ 18 F]FDG uptake by autoradiography and 2-DG incorporation by colorimetric assay, although radiotracer-based methods exhibited more pronounced differences between individual cell lines. As expected, these data correlated with glucose transporters 1 to 4 and hexokinase II expression in tumor cell lines and mouse fibroblasts. Notably, [ 18 F]FDG incorporation resulted in low apoptotic rates, with fibroblasts being slightly more sensitive to radiotracer-induced cell death. The quantitative analysis of [ 18 F]FDG uptake in living cells by PET represents a valuable and reproducible method to study tumor cell metabolism in vitro, being representative of the differences in the molecular profile of normal and tumor cell lines

Older people with hip fracture and IADL disability require earlier surgery

Background: Hip fractures represent a major challenge for physicians as well as society as a whole. Both poor functional status and delay to surgery are well known risk factors for negative outcomes. We hypothesized that the timing of the operation is more important for frail older people than older people without functional limitations before fracture. Methods: We performed a prospective multicenter cohort study on 806 consecutive patients, 75 years of age or older, admitted with a fragility hip fracture to three hospitals in the Emilia-Romagna Region (Italy). All three hospitals had a comanaged care model, and the patients were under the shared responsibility of an orthopedic surgeon and a geriatrician. Results: Functional status assessed as instrumental activities of daily living was an important predictor of survival after 1 year from fracture. After adjusting for confounders, the hazard ratios per 1 point score of increase from 0 to 8 was 1.30 (95% confidence interval 1.19-1.42, p =. 000). Time to surgery increased 1-year mortality in patients with a low instrumental activities of daily living score (hazard ratios per day of surgical delay 1.14, 95% confidence interval 1.06-1.22, p &lt;. 001) and intermediate instrumental activities of daily living score (hazard ratios 1.21, 95% confidence interval 1.09-1.34, p &lt;. 001) but was an insignificant risk factor in functionally independent patients (hazard ratios 1.05 95% confidence interval 0.79-1.41, p =. 706). Conclusions: Surgery delay is an independent factor for mortality in older patients after hip fracture but only for the frail older people with prefracture functional impairment. If our results are confirmed, a more intensive approach should be adopted for older people with hip fractures who have disabilities. © 2012 The Author

A stapled chromogranin A-derived peptide is a potent dual ligand for integrins αvβ6 and αvβ8

Combining 2D STD-NMR, computation, biochemical assays and click-chemistry, we have identified a chromogranin-A derived compound (5) that has high affinity and bi-selectivity for αvβ6 and αvβ8 integrins and is stable in microsomal preparations

Sea surface temperature intercomparison in the framework of the Copernicus Climate Change Service (C3S)

A joint effort between the Copernicus Climate Change Service (C3S) and the Group for High Resolution Sea Surface Temperature (GHRSST) has been dedicated to an intercomparison study of eight global gap-free Sea Surface Temperature (SST) products to assess their accurate representation of the SST relevant to climate analysis. In general, all SST products show consistent spatial patterns and temporal variability during the overlapping time period (2003-2018). The main differences between each product are located in western boundary current and Antarctic Circumpolar Current regions. Linear trends display consistent SST spatial patterns among all products and exhibit a strong warming trend from 2012 to 2018 with the Pacific Ocean basin as the main contributor. SST discrepancy between all SST products is very small compared to the significant warming trend. Spatial power spectral density shows that the interpolation into 1o spatial resolution has negligible impacts on our results. The global mean SST time series reveals larger differences among all SST products during the early period of the satellite era (1982-2002) when there were fewer observations, indicating that the observation frequency is the main constraint of the SST climatology. The maturity matrix scores, which present the maturity of each product in terms of documentation, storage, and dissemination but not the scientific quality, demonstrate that ESA-CCI and OSTIA SST are well documented for users' convenience. Improvements could be made for MGDSST and BoM SST. Finally, we have recommended that these SST products can be used for fundamental climate applications and climate studies (e.g. El Nino)

Guidelines on the diagnosis, treatment and management of visceral and renal arteries aneurysms: a joint assessment by the Italian Societies of Vascular and Endovascular Surgery (SICVE) and Medical and Interventional Radiology (SIRM)

: The objective of these Guidelines is to provide recommendations for the classification, indication, treatment and management of patients suffering from aneurysmal pathology of the visceral and renal arteries. The methodology applied was the GRADE-SIGN version, and followed the instructions of the AGREE quality of reporting checklist. Clinical questions, structured according to the PICO (Population, Intervention, Comparator, Outcome) model, were formulated, and systematic literature reviews were carried out according to them. Selected articles were evaluated through specific methodological checklists. Considered Judgments were compiled for each clinical question in which the characteristics of the body of available evidence were evaluated in order to establish recommendations. Overall, 79 clinical practice recommendations were proposed. Indications for treatment and therapeutic options were discussed for each arterial district, as well as follow-up and medical management, in both candidate patients for conservative therapy and patients who underwent treatment. The recommendations provided by these guidelines simplify and improve decision-making processes and diagnostic-therapeutic pathways of patients with visceral and renal arteries aneurysms. Their widespread use is recommended

Thermal Stability of Ionic Liquids: Effect of Metals

We investigated the thermal stability and corrosion effects of a promising ionic liquid (IL) to be employed as an advanced heat transfer fluid in solar thermal energy applications. Degradation tests were performed on IL samples kept in contact with various metals (steel, copper and brass) at 200 &deg;C for different time lengths. Structural characterization of fresh and aged IL samples was carried out by high-resolution magic angle spinning nuclear magnetic resonance and Fourier transform infrared spectroscopic analyses, while headspace gas chromatography&ndash;mass spectrometry was employed to evaluate the release of volatile organic compounds. The combination of the above-mentioned techniques effectively allowed the occurrence of degradation processes due to aging to be verified

Studio NMR di fenomeni di enantiodiscriminazione originati da sistemi poliammidici a basso peso molecolare e concatenati a strutture resorcareniche

Ausiliari chirali poliammidici sono stati caratterizzati tramite spettroscopia 1H e 13C NMR per analisi combinata di mappe di correlazione omonucleari g-COSY (gradient-COrrelation SpectroscopY), ROESY (Rotating-frame Overhauser Enhancement SpectroscopY) e TOCSY (TOtally Correlated SpectroscopY) ed eteronucleari g-HSQC (gradient-Heteronuclear Single Quantum Coherence) e HMBC (Heteronuclear Multiple Bond Coherence). Tali composti sono stati quindi impiegati come agenti solvatanti chirali per l’enantiodiscriminazione dell’acido mandelico in cloroformio. Sono state indagate le proprietà enantiodiscriminanti di ciascun recettore nelle miscele con il substrato racemo, analizzando le anisocronie rilevate negli spettri 1H NMR in seguito alla formazione dei due complessi diastereomerici; sono state acquisite mappe DOSY per la determinazione dei coefficienti di diffusione, al fine di valutare la frazione molare del substrato legato al recettore per ciascuno dei due complessi diastereomerici; sono state acquisite mappe ROESY per indagare i siti di interazione tra ausiliari chirali e acido mandelico