72 research outputs found
Formation of Nanostructured Al-Mg-Si Alloys and Evaluation Its Properties
In this study, nanostructured Al-Mg-Si (Al6061) alloy was prepared from elemental powders by mechanical alloying and heat treatment. 98.4% aluminum, 1% magnesium, 0.6% silicon powders were mixed
and mechanically alloyed under argon atmosphere. The rotation speed of 500rpm and ball to powder ratio
of 10:1 was employed. The mechanical alloyed powder was isothermally heat treated at 400 degrees Celsius for 2 h under argon atmosphere.
The results showed that after 10h of milling, a solid solution of Al-Mg-Si with a grain size of ~ 40 nm
was produced. The as milled and annealed powder was characterized by scanning electron microscopy
(SEM) and X-ray diffraction (XRD). The microhardness values of alloy increase by increasing MA time.
Mg2Si particles precipitate from solid solution during subsequent annealing. The as milled powder
appeared to have good thermal stability against grain growth so that the grain size after annealing
remained constant (~ 40 nm).
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3486
Highly sensitive C-reactive protein levels in Iranian patients with pulmonary complication of sulfur mustard poisoning and its correlation with severity of airway diseases
Background: Sulfur mustard (SM) is a chemical warfare agent that can cause serious pulmonary complications.
This study was designed to determine serum highly sensitive C-reactive protein (hs-CRP) and evaluate its
correlation with lung function parameters in patients with chronic obstructive pulmonary disease (COPD) due
to SM poisoning. Methods: Fifty consecutive SM patients with stable COPD and a mean age 46.3 + 9.18 years
were enrolled in this cross sectional study. Thirty healthymen were selected as controls. Lung function parameters
were evaluated. Serum hs-CRP by immunoturbidometry assay was measured in both the patients and controls.
Results: In the case group, the mean forced expiratory volume in one second (FEV1) was 2.14 + 0.76 L
(58.98%+17.51% predicted). The mean serum hs-CRP was 9.4+6.78 SD and 3.9+1.92 SDmg/L in the cases
and controls, respectively, with significant statistical differences (p < .001). There was negative correlation between
the serum hs-CRP and FEV1 levels (p ¼ .01). The serum hs-CRP levels were also correlated with Global Initiative
for ChronicObstructive Lung disease (GOLD) stages (r ¼ .45, p < .001). Conclusions:Our findings suggest that
the serum hs-CRP level is increased in SM patients with COPD and may have a direct correlation with disease
severity. It may then be used as a marker for the severity of COPD in patients with SM poisoning
A MASH simulation of the photoexcited dynamics of cyclobutanone
In response to a community prediction challenge, we simulate the nonadiabatic
dynamics of cyclobutanone using the mapping approach to surface hopping (MASH).
We consider the first 500 fs of relaxation following photo-excitation to the S2
state and predict the corresponding time-resolved electron-diffraction signal
that will be measured by the planned experiment. 397 ab-initio trajectories
were obtained on the fly with state-averaged complete active space
self-consistent field (SA-CASSCF) using a (12,11) active space. To obtain an
estimate of the potential systematic error 198 of the trajectories were
calculated using an aug-cc-pVDZ basis set and 199 with a 6-31+G* basis set.
MASH is a recently proposed independent trajectory method for simulating
nonadiabatic dynamics, originally derived for two-state problems. As there are
three relevant electronic states in this system, we used a newly developed
multi-state generalisation of MASH for the simulation: the uncoupled spheres
multi-state MASH method (unSMASH). This study therefore serves both as an
investigation of the photo-dissociation dynamics of cyclobutanone, and also as
a demonstration of the applicability of unSMASH to ab-initio simulations. In
line with previous experimental studies, we observe that the simulated dynamics
is dominated by three sets of dissociation products, C3H6+CO, C2H4+C2H2O and
C2H4+CH2+CO, and we interpret our predicted electron-diffraction signal in
terms of the key features of the associated dissociation pathways.Comment: 47 pages, 43 figure
Chemical composition, free-radical-scavenging and insecticidal activities of the aerial parts of Stachys byzantina
Stachys byzantina K. Koch. is an Iranian endemic species of the genus Stachys L., which comprises about 300 species, and is one of the largest genera of the family Lamiaceae. A combination of solid phase extraction (SPE) and high pressure liquid chromatography (HPLC) of the methanolic extract of the aerial parts of S. byzantina afforded three phenylethanoids, 2'-O-arabinosyl verbascoside (1), verbascoside (2), aeschynanthoside C (3) and three flavones apigenin 7-O-glucoside (4), apigenin 7-O-(6-p-coumaroyl)-glucoside (5) and apigenin (6). The structures of these compounds were determined by spectroscopic methods. Free-radical-scavenging and insecticidal properties of the crude extracts, the fractions and the isolated compounds were assessed.
Quantitative multiplex immunohistochemistry reveals inter-patient lymphovascular and immune heterogeneity in primary cutaneous melanoma
IntroductionQuantitative, multiplexed imaging is revealing complex spatial relationships between phenotypically diverse tumor infiltrating leukocyte populations and their prognostic implications. The underlying mechanisms and tissue structures that determine leukocyte distribution within and around tumor nests, however, remain poorly understood. While presumed players in metastatic dissemination, new preclinical data demonstrates that blood and lymphatic vessels (lymphovasculature) also dictate leukocyte trafficking within tumor microenvironments and thereby impact anti-tumor immunity. Here we interrogate these relationships in primary human cutaneous melanoma. MethodsWe established a quantitative, multiplexed imaging platform to simultaneously detect immune infiltrates and tumor-associated vessels in formalin-fixed paraffin embedded patient samples. We performed a discovery, retrospective analysis of 28 treatment-naïve, primary cutaneous melanomas. ResultsHere we find that the lymphvasculature and immune infiltrate is heterogenous across patients in treatment naïve, primary melanoma. We categorized five lymphovascular subtypes that differ by functionality and morphology and mapped their localization in and around primary tumors. Interestingly, the localization of specific vessel subtypes, but not overall vessel density, significantly associated with the presence of lymphoid aggregates, regional progression, and intratumoral T cell infiltrates. DiscussionWe describe a quantitative platform to enable simultaneous lymphovascular and immune infiltrate analysis and map their spatial relationships in primary melanoma. Our data indicate that tumor-associated vessels exist in different states and that their localization may determine potential for metastasis or immune infiltration. This platform will support future efforts to map tumor-associated lymphovascular evolution across stage, assess its prognostic value, and stratify patients for adjuvant therapy
The use of plants in the traditional management of diabetes in Nigeria: Pharmacological and toxicological considerations
Ethnopharmacological relevance: The prevalence of diabetes is on a steady increase worldwide and it is now identified as one of the main threats to human health in the 21st century. In Nigeria, the use of herbal medicine alone or alongside prescription drugs for its management is quite common. We hereby carry out a review of medicinal plants traditionally used for diabetes management in Nigeria. Based on the available evidence on the species׳ pharmacology and safety, we highlight ways in which their therapeutic potential can be properly harnessed for possible integration into the country׳s healthcare system.
Materials and methods: Ethnobotanical information was obtained from a literature search of electronic databases such as Google Scholar, Pubmed and Scopus up to 2013 for publications on medicinal plants used in diabetes management, in which the place of use and/or sample collection was identified as Nigeria. ‘Diabetes’ and ‘Nigeria’ were used as keywords for the primary searches; and then ‘Plant name – accepted or synonyms’, ‘Constituents’, ‘Drug interaction’ and/or ‘Toxicity’ for the secondary searches.
Results: The hypoglycemic effect of over a hundred out of the 115 plants reviewed in this paper is backed by preclinical experimental evidence, either in vivo or in vitro. One-third of the plants have been studied for their mechanism of action, while isolation of the bioactive constituent(s) has been accomplished for twenty three plants.
Some plants showed specific organ toxicity, mostly nephrotoxic or hepatotoxic, with direct effects on the levels of some liver function enzymes. Twenty eight plants have been identified as in vitro modulators of P-glycoprotein and/or one or more of the cytochrome P450 enzymes, while eleven plants altered the levels of phase 2 metabolic enzymes, chiefly glutathione, with the potential to alter the pharmacokinetics of co-administered drugs.
Conclusion: This review, therefore, provides a useful resource to enable a thorough assessment of the profile of plants used in diabetes management so as to ensure a more rational use. By anticipating potential toxicities or possible herb–drug interactions, significant risks which would otherwise represent a burden on the country׳s healthcare system can be avoided
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