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A Comparative Molecular Dynamics, MM−PBSA and Thermodynamic Integration Study of Saquinavir Complexes with Wild-Type HIV‑1 PR and L10I, G48V, L63P, A71V, G73S, V82A and I84V Single Mutants
Get PDFA great challenge toward Acquired Immunodeficiency Syndrome (AIDS) treatment is to combat the HIV-1 virus. The major problem of drug resistance has kept the virus one step ahead of the medical community, and the call for more effective drugs remains as urgent as ever. Saquinavir, the first inhibitor against HIV-1 protease, offers the most extensive clinical data regarding resistance mutations. In this work, we examine L10I, G48V, L63P, A71V, G73S, V82A, and I84V single mutant HIV-1 PR strains in complexes with saquinavir to elucidate drug–protease interactions and dynamics. A comparative analysis of these mutations at the molecular level may lead to a deeper understanding of saquinavir resistance. The G48V mutation induces structural changes to the protease that reflect upon the drug’s binding affinity, as shown by MM–PBSA and thermodynamic integration (TI) calculations (ΔΔGTI = 0.3 kcal/mol; ΔΔGMM–PBSA = 1.2 kcal/mol). It was shown that mutations, which increase the flexibility of the flaps (G48V, L63P, L10I) diminish binding. The preservation of hydrogen bonds of saquinavir with both the active site and flap residues in the wild-type and certain single mutants (A71V, V82A) is also crucial for effective inhibition. It was shown that mutations conferring major resistance (G48V, L63P, I84V) did not present these interactions. Finally, it was indicated that a water-mediated hydrogen bond between saquinavir and Asp29 in the active site (wild-type, A71V, G73S) facilitates a proper placement of the drug into the binding cavity that favors binding. Mutants lacking this interaction (G48V, V82A, I84V) demonstrated reduced binding affinities. This systematic and comparative study is a contribution to the elucidation of the drug resistance mechanism in HIV-1 PR
Μελέτη για τα επαγγελματικά δικαιώματα στην Ελλάδα και τη σχέση τους με το εκπαιδευτικό σύστημα και το σύστημα αρχικής επαγγελματικής κατάρτισης: Παραρτήματα Π3-Π11
No full textThe primary instability of falling lms in the presence of soluble surfactants
Get PDFWe investigate the linear stability of a film flowing down a solid substrate in the presence of soluble surfactants. The Navier-Stokes equations for the liquid motion are considered, together with advection-diffusion equations for the concentrations of the species involved, which include monomers and micelles in the bulk and monomers adsorbed at the liquid-air interface. The adsorption-desorption kinetics of the surfactant at the interface is explicitly accounted for. An Orr-Sommerfeld eigenvalue problem is formulated, and solved analytically in the limit of long-wave disturbances and numerically for arbitrary wavelength using a finite
element method. An extensive parametric study is performed to reveal the role of surfactant solubility and adsorption-desorption kinetics. The results quantify the stabilizing effect of soluble surfactants due to the presence of Marangoni stresses, and indicate that moderately soluble surfactants may be more effective than insoluble ones. Disturbances of finite wavelength are stabilized by more than an order of magnitude, and their detailed behavior depends in a non-monotonic way on the amount of surfactant and on its solubility and
kinetics. The above predictions provide insights for the interpretation of recent experimental findings on the primary instability and on the ensuing unstable dynamics of liquid films doped with soluble surfactants
Bladder cancer and arsenic through drinking water: A systematic review of epidemiologic evidence
Get PDFExposure to inorganic arsenic (As) through drinking water is a major international public health issue. We carried out a systematic review of the existing literature examining the association between the risk of bladder cancer in humans and exposure to arsenic through drinking water.We searched electronic databases for studies published from January 2000 up to April 2013. Eight ecological studies, six case-control studies, four cohort studies and two meta-analyses were identified. The vast majority of the studies were carried out in areas with high arsenic concentrations in drinking water such as southwestern and northeastern Taiwan, Pakistan, Bangladesh, Argentina (Cordoba Province), USA (southeastern Michigan, Florida, Idaho) and Chile. Most of the studies reported higher risks of bladder cancer incidence or mortality in areas with high arsenic concentrations in drinking water compared to the general population or a low arsenic exposed control group. The quality assessment showed that among the studies identified, arsenic exposure was assessed at the individual level only in half of them and only three assessed exposure using a biomarker. Further, five out of eight ecological studies presented results with adjustment for potential confounders except for age; all cohort and case-control studies presented results with adjustment for cigarette smoking status in the analysis. The majority of the studies with varying study designs carried out in different areas provided evidence of statistically siginificant increases in bladder cancer risk at high concentrations of arsenic (>50 μg L−1). Assessing bladder cancer risk at lower exposure concentrations requires further investigation
Fish otoliths from the Pliocene Heraklion Basin (Crete Island, Eastern Mediterranean)
Get PDFThe Pliocene Eastern Mediterranean fish record is revealed through the study of a 60-m thick stratigraphic sequence near the village Voutes (Heraklion, Crete). Forty-two species belonging to twenty families are identified. Calcareous nannoplankton biostratigraphy places the studied sequence within the biozone MNN16a (latest Zanclean). The stratigraphic distribution of 31 species is modified. Among these, 12 species are reported for the first time in the Eastern Mediterranean Zanclean, while 19 species are first reported outside the Ionian Sea. The Voutes fish fauna presents a diversified benthic and benthopelagic assemblage filling a significant gap in the fossil record
RouteMate, a location based route learning system for users with disabilities: a playful methodological experience in different urban European landscapes
Get PDFIn this paper, we will present the piloting methodology as well as the results from four different
European countries, using RouteMate in a series of piloting sessions targeted to people in a vast age and
ability range. We will also document the integration of
RouteMate with playful scenarios, as well as the
motivational qualities of such an integration for users
with disabilities on open route learning in five different European cities
Perspective rectification of integral images produced using arrays of circular lenses
Get PDFThere are many different three-dimensional (3D) techniques to capture and deliver autostereoscopic 3D content. A promising technique that provides two-dimensional parallax as well as high-quality, full-color 3D content is integral imaging (InI). Misalignments between the lens arrays (LAs) and the camera charged coupled device, however, introduce geometric distortions in the acquired image that propagate through the different image processing stages and deteriorate the 3D effect. Here, we propose a method to accurately rectify the perspective distortion of integral images (InIms) generated using circular lenses. Using an edge-linking approach, we extracted elliptically shaped contours of elemental images in the perspectively distorted InIm. To calculate the rectification matrix, we used the images of the circular points. Subsequently, we applied a triangulation scheme followed by a statistical approach to accurately estimate the grid structure of the LA. Finally, we provided experimental results over a wide range of InIms to evaluate the robustness and accuracy of the proposed method using objective metrics
A crosstalk between p21 and UPR-induced transcription factor C/EBP homologous protein (chop) linked to type 2 diabetes
Get PDFType 2 diabetes (T2D) is a disease that is characterized by raised levels of glucose in the blood combined with insulin resistance and relative insulin deficiency. The pathogenesis of type 2 diabetes is associated with the induction of the unfolded protein response (UPR). While UPR aims to restore tissue homeostasis following stress of the endoplasmic reticulum (ER), prolonged ER stress triggers apoptosis at least in part through the unfolded protein response (UPR)-activated transcription factor C/EBP (CCAAT/enhancer binding protein) homologous protein (CHOP). CHOP has elevated as a critical mediator connecting accumulation and aggregation of unfolded proteins in the ER and oxidative stress and also contributes to the induction of apoptosis in β-cell (beta-cell) – cells under conditions of increased insulin demand. p21 is a cell cycle regulator that is implicated in the regulation of the UPR by various mechanisms involving inhibition of apoptosis and facilitation of the regeneration capacity of the β cells. In this review we summarize the role of ER stress in the pathogenesis of type 2 diabetes which is associated with the induction of the unfolded protein response (UPR). We also review recent evidence associating p21 activity with β cell health and regenerative capacity by mechanisms that may interfere with the effects of p21 in the UPR or operate independently of ER stress. Most likely understanding the molecular details of the pathogenesis of type 2 diabetes will be beneficial for the management of the disease
Προγράμματα σπουδών ενηλίκων: 2ος κύκλος εκπαιδευτικών προγραμμάτων: Φεβρουάριος 2013 – Απρίλιος 2013
Get PDFΠεριλαμβάνονται τα πακέτα εργασίας:
ΠΕ 1.1 - Σχεδιασμός και προγραμματισμός εκπαιδευτικών
προγραμμάτων
ΠΕ 1.2 - Οργάνωση εκπαιδευτικών προγραμμάτων
ΠΕ 1.3 - Υλοποίηση εκπαιδευτικών προγραμμάτων
ΠΕ 1.4 - Αξιολόγηση εκπαιδευτικών προγραμμάτω
Προγράμματα σπουδών ενηλίκων: 3ος κύκλος εκπαιδευτικών προγραμμάτων: Απρίλιος 2013 – Ιούλιος 2013
Get PDFΠεριλαμβάνονται τα πακέτα εργασίας:
ΠΕ 1.1 - Σχεδιασμός και προγραμματισμός εκπαιδευτικών
προγραμμάτων
ΠΕ 1.2 - Οργάνωση εκπαιδευτικών προγραμμάτων
ΠΕ 1.3 - Υλοποίηση εκπαιδευτικών προγραμμάτων
ΠΕ 1.4 - Αξιολόγηση εκπαιδευτικών προγραμμάτω