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Clear-cut Evidence (clear-cut + evidence)

Distribution by Scientific Domains

Chemistry	50%

Selected Abstracts

THE UNEMPLOYMENT PARADIGMS REVISITED: A COMPARATIVE ANALYSIS OF U.S. STATE AND EUROPEAN UNEMPLOYMENT

CONTEMPORARY ECONOMIC POLICY, Issue 3 2009
DIEGO ROMERO-ÁVILA
This article tests the main unemployment paradigms for the unemployment rates of the states of the United States and the European Union,15 countries over the past three decades. For that purpose, we employ a state-of-the-art panel stationarity test, which allows for an unknown number of endogenous structural breaks as well as for cross-sectional correlation. Overall, our analysis renders clear-cut evidence in favor of regime-wise stationarity in U.S. state unemployment, while hysteresis in European unemployment. Interestingly, the timing of the breaks broadly coincides with major macroeconomic shocks mainly associated with the oil crises of the 1970s and marked changes in interest rates in the 1980s and early 1990s. Based on our results, we draw some policy prescriptions that point to the need for greater flexibility in the European labor markets. (JEL C23, E24) [source]

Merging of E2 and E1cb Reaction Mechanisms: A Combined Theoretical and Experimental Study

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 32 2009
Edoardo Mosconi
Abstract By combining the results of kinetic measurements with DFT calculations we provide a clear-cut evidence of the merging between the E2 and E1cb reaction mechanisms for a large series of leaving groups. Our results solve a long-debated issue in chemical reactivity with profound implications both from a fundamental and biological point of view, thus paving the way to further investigations with different substrates.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]

Allosteric modulation of anti-HIV drug and ferric heme binding to human serum albumin

FEBS JOURNAL, Issue 24 2005
Alessio Bocedi
Human serum albumin (HSA), the most prominent protein in plasma, is best known for its exceptional capacity to bind ligands (e.g. heme and drugs). Here, binding of the anti-HIV drugs abacavir, atazanavir, didanosine, efavirenz, emtricitabine, lamivudine, nelfinavir, nevirapine, ritonavir, saquinavir, stavudine, and zidovudine to HSA and ferric heme,HSA is reported. Ferric heme binding to HSA in the absence and presence of anti-HIV drugs was also investigated. The association equilibrium constant and second-order rate constant for the binding of anti-HIV drugs to Sudlow's site I of ferric heme,HSA are lower by one order of magnitude than those for the binding of anti-HIV drugs to HSA. Accordingly, the association equilibrium constant and the second-order rate constant for heme binding to HSA are decreased by one order of magnitude in the presence of anti-HIV drugs. In contrast, the first-order rate constant for ligand dissociation from HSA is insensitive to anti-HIV drugs and ferric heme. These findings represent clear-cut evidence for the allosteric inhibition of anti-HIV drug binding to HSA by the heme. In turn, anti-HIV drugs allosterically impair heme binding to HSA. Therefore, Sudlow's site I and the heme cleft must be functionally linked. [source]

Preoperative staging and evaluation of resectability in pancreatic ductal adenocarcinoma

HPB, Issue 1 2004
R Andersson
Background Cancer of the pancreas is a common disease, but the large majority of patients have tumours that are irresectable at the time of diagnosis. Moreover, patients whose tumours are clearly beyond surgical cure are best treated non-operatively, if possible, by relief of biliary obstruction and percutaneous biopsy to confirm the diagnosis and then consideration of oncological treatment, notably chemotherapy. These facts underline the importance of a standard protocol for the preoperative determination of operability (is it worth operating?) and resectability (is there a chance that the tumour can be removed?). Recent years have seen the advent of many new techniques, both radiological and endoscopic, for the diagnosis and staging of pancreatic cancer. It would be impracticable in time and cost to submit every patient to every test. This review will evaluate the available techniques and offer a possible algorithm for use in routine clinical practice. Discussion In deciding whether to operate with a view to resecting a pancreatic cancer, the surgeon must take into account factors related to the patient, the tumour and the institution and team entrusted with the patient's care. Patient-related factors include age, general health, pain and the presence or absence of malnutrition and an acute phase inflammatory response. Tumour-related factors include tumour size and evidence of spread, whether to adjacent organs (notably major blood vessels) or further afield. Hospital-related factors chiefly concern the volume of pancreatic cancer treated and thus the experience of the whole team. Determination of resectability is heavily dependent upon detailed imaging. Nowadays conventional ultrasonography can be supplemented by endoscopic, laparoscopic and intra-operative techniques. Computed tomography (CT) remains the single most useful staging modality, but MRI continues to improve. PET scanning may demonstrate unsuspected metastases and likewise laparoscopy. Diagnostic cholangiography can be performed more easily by MR techniques than by endoscopy, but ERCP is still valuable for preoperative biliary decompression in appropriate patients. The role of angiography has declined. Percutaneous biopsy and peritoneal cytology are not usually required in patients with an apparently resectable tumour. The prognostic value of tumour marker levels and bone marrow biopsy is yet to be established. Preoperative chemotherapy or chemoradiation may have a role in down-staging an irresectable tumour sufficiently to render it resectable. Selective use of diagnostic laparoscopy staging is potentially helpful in determination of resectability. Laparotomy remains the definitive method for determining the resectability of pancreatic cancer, with or without portal vein resection, and should be undertaken in suitable patients without clear-cut evidence of irresectability. [source]