43 research outputs found
Polymer coated gold nanoshells for combinational photochemotherapy of pancreatic cancer with gemcitabine
Get PDFPancreatic cancer is one of the most lethal malignancies with limited therapeutic options and
dismal prognosis. Gemcitabine is the front-line drug against pancreatic cancer however with limited
improvement of therapeutic outcomes. In this study we envisaged the integration of GEM with
gold nanoshells which constitute an interesting class of nanomaterials with excellent photothermal
conversion properties. Nanoshells were coated with thiol-capped poly(ethylene glycol) methacrylate
polymers of different molecular weight via Au–S attachment. It was found that the molecular
weight of the polymers affects the in vitro performance of the formulations; more importantly we
demonstrate that the EC50
of nanoshell loaded GEM can be suppressed but fully restored and even
improved upon laser irradiation. Our proposed nanoformulations outperformed the cytotoxicity of the
parent drug and showed confined synergism under the tested in vitro conditions
Catecholamines are active plant-based drug compounds in Pisum sativum, Phaseolus vulgaris and Vicia faba Species
Get PDFIntroduction: Catecholamines (L-DOPA and dopamine) are the key metabolites found in nervous system and their endogenous deficiency is associated with different patho-physiological disorders. Therefore, it is important to screen the new herbal sources of catecholamines for drug preparation. In this study, the amount of L-DOPA and dopamine were investigated in the leaves and roots of three species from legume family such as Pisum sativum (garden pea), Phaseolus vulgaris (haricot bean) and Vicia faba (broad bean); using TLC and HPLC. Methods: The seeds of P. sativum, P. Vulgaris and V. faba were treated and cultured under the glasshouse conditions. The extraction from 1 gram of each plant sample was obtained and assayed for L-DOPA and dopamine using thin layer chromatography (TLC) and reversed-phase HPLC. Results: The results indicated that all cultivars accumulated different levels of L-DOPA and dopamine in leaves and roots. The quantitative results showed that the metabolites concentrations were high in the leaves of P. Sativum and V. faba compared to that in roots. Conclusion: The present study may provide a new avenue for preparation and estimation of L-DOPA and dopamine from plant sources and may be used for further analysis and therapeutic studies.</p
Development and psychometric evaluation of the nursing instructors' clinical teaching performance inventory
Get PDFEvaluation of nursing instructors' clinical teaching performance is a prerequisite to the quality assurance of nursing education. One of the most common procedures for this purpose is using student evaluations. This study was to develop and evaluate the psychometric properties of Nursing Instructors' Clinical Teaching Performance Inventory (NICTPI). The primary items of the inventory were generated by reviewing the published literature and the existing questionnaires as well as consulting with the members of the Faculties Evaluation Committee of the study setting. Psychometric properties were assessed by calculating its content validity ratio and index, and test-retest correlation coefficient as well as conducting an exploratory factor analysis and an internal consistency assessment. The content validity ratios and indices of the items were respectively higher than 0.85 and 0.79. The final version of the inventory consisted of 25 items, and in the exploratory factor analysis, items were loaded on three factors which jointly accounting for 72.85 of the total variance. The test-retest correlation coefficient and the Cronbach's alpha of the inventory were 0.93 and 0.973, respectively. The results revealed that the developed inventory is an appropriate, valid, and reliable instrument for evaluating nursing instructors' clinical teaching performance
Dual controlled delivery of squalenoyl-gemcitabine and paclitaxel using thermo-responsive polymeric micelles for pancreatic cancer
Get PDFIn this study we report the synthesis of a themroresponsive block copolymer by reversible addition
fragmentation transfer polymerization comprising poly(2-ethylhexyl methacrylate)-b-poly[di(ethylene
glycol)methyl ether methacrylate-co-oligo(ethylene glycol)methyl ether methacrylate] as hydrophobic
and thermoresponsive blocks respectively. The polymer self-assembles into sub-50 micelles and can
carry simultaneously two drug molecules, namely squalene-gemcitabine and paclitaxel. Both drugs can
be released from the micellar compartment in a thermally controlled manner owing to the controllable
disruption of the micellar corona above the lower critical solution temperature of the polymer. We
demonstrate that the formulation augments synergistically the cytotoxicity of the two drugs in vitro
against a model pancreatic cancer cell line. More importantly, it is shown that the polymer exerts a
direct interaction with the cell membrane which further augments the cytotoxicity of the drug cargo in
a thermally controlled manne
Microchimerism and Renal Transplantation: Doubt Still Persists
Get PDFObjective: We sought to study microchimerism in a group of kidney transplant recipients. Materials and Methods: In this study, the peripheral blood microchimerism (PBM) after renal transplantation was retrospectively evaluated in 32 male-to-female recipients of living unrelated or cadaveric donor renal transplants. Using a nested polymerase chain reaction (PCR) amplification specific for SRY region of the Y chromosome, microchimerism was detected with a sensitivity of 1:1,000,000. Recipients were compared according to the presence of PBM, acute and chronic rejection episodes, type of allotransplant, recipient and donor age at transplantation, previous male labor or blood transfusion, allograft function (serum creatinine level), and body mass index. Results: Among 32 recipients, 7 (21.9) were positive for PBM upon multiple testing at various posttransplant times. All microchimeric recipients had received kidneys from living unrelated donors. No significant difference was observed with regard to other parameters. In addition the acute rejection rate in the microchimeric group was 3 (42) versus 4 (16) in the nonmicrochimeric recipients (not significant). Conclusion: Our results suggested better establishment of microchimerism after living donor kidney transplantation. However, doubt persists concerning the true effect of microchimerism after renal transplantation. It seems that microchimerism alone has no major protective role upon renal allograft survival. © 2007 Elsevier Inc. All rights reserved
Apolipoprotein E and Alzheimer’s disease: The influence of apolipoprotein E on amyloid- and other amyloidogenic proteins
Get PDFSmall molecule probes of protein aggregation
Get PDFUnderstanding the mechanisms of amyloid formation and toxicity remain major challenges. Whilst substantial progress has been made in the development of methods able to identify the species formed during self-assembly and to describe the kinetic mechanisms of aggregation, the structure(s) of non-native species, including potentially toxic oligomers, remain elusive. Moreover, how fibrils contribute to disease remains unclear. Here we review recent advances in the development of small molecules and other reagents that are helping to define the mechanisms of protein aggregation in molecular detail. Such probes form a powerful platform with which to better define the mechanisms of structural conversion into amyloid fibrils and may provide the much-needed stepping stone for future development of successful therapeutic agents
Nonlinear Fredholm Integral Equation of the Second Kind with Quadrature Methods
No full textIn this paper, a numerical method for solving the nonlinear
Fredholm integral equation is presented. We intend to approximate the
solution of this equation by quadrature methods and by doing so, we
solve the nonlinear Fredholm integral equation more accurately. Several
examples are given at the end of this pape
Transiently malleable multi-healable hydrogel nanocomposites based on responsive boronic acid copolymers
No full textThe design of materials that mimic aspects of self-healing, as observed in nature, is of paramount importance as they could solve a number of problems in the biomedical field, such as the elimination of (bio-)material failure after prolonged use, improved integration at the interface with living tissues and more robust biomechanical performance. In this report, we propose the fabrication of soft hydrogels comprising a polymer matrix of poly(vinyl alcohol) mixed with a thermoresponsive boronic acid copolymer that is subsequently impregnated with poly(vinyl pyrrolidone) coated gold nanoparticles. The gels are crosslinked by the formation of reversible boronate ester bonds that can be remotely disrupted by a thermal or optical stimulus, endowing the gels with thermally-induced transient malleability that is optically trackable. It is demonstrated that the gels exhibit excellent healing properties within minutes even without the application of external stimuli. The rapid formation of the gels in concert with their fast and mild gel–sol phase transition under biologically relevant conditions is demonstrated by the encapsulation and release of cells in vitro. The proposed materials constitute a versatile cytocompatible platform for the construction of remotely healable soft gels for biomedical applications
THE STUDY OF RISK MANAGEMENT OF WATER AND WASTEWATER FACILITIES USING COMBINED METHOD AHP AND RAMCAP
No full textWater and wastewater facilities are the key assets and infrastructure of any country, and any service stop and damage to the infrastructure may have social
and political problems and endanger the health and life of humans. Therefore,
the study of asset valuation of these facilities against potential attacks is necessary to enable decision-makers to reduce potential risks. In the present
study, the proposed combination of RAMCAP and Analytical Hierarchy Process
(AHP) analysis of the total water and sewage infrastructure in Tehran based on
the value of the assets and riskiness was investigated. We used a pairwise
matrix method by receiving 42 expert opinions. To analyze the data, the AHP was
used by applying RAMCAP guide. Moreover, to keep the paired comparison of each respondent reasonable, the inconsistency ratio was determined. The results of this study indicated that, because of the importance of assets, the Latian Dam
with asset value 1 has the highest asset value and, then, Lar Dam with a value
of 0.6920 in the second position and the distribution network of water and
reservoirs with asset values of 0.0312 and 0.0310 based on three criteria of
economic value, functional value, and uniqueness is in the last position of
this value, respectively. Furthermore, 12 different threats were evaluated. In
the case of chemical, microbial, and nuclear attacks, a number close to 1 is
most likely to occur. The greatest vulnerability of the chemical threat, microbial and nuclear attacks belongs to the Latian dam with a vulnerability of 0.9310 and the Amir Kabir dam with 0.8353. Taleghan Dam with a vulnerability of 0.6304 was in the third position
