1,014 research outputs found
Environmental factors and breast cancer
Breast cancer is the most common form of cancer in women in the world. Although, certain risk factors for breast cancer, such as age at menarch, diet and genetic predisposition have been well known for years, many breast cancer cases occur in women with no known risk factors for disease. Today, some of the environmental factors such as environmental estrogens have been connected to breast cancer incidence which increase the rate of 16α-hydroxyestrone (bad estrogen) to 2-hydroxyestrone (good estrogen) in cancerous cells. In comparison to environmental estrogen, phytoestrogen decrease the risk of breast cancer. In this article some of the effective environmental factors in breast cancer incidence and their comparison to phytoestrogens as one of the inhibiting factors are described. © Global Science Publications
Effects of hybrid post-treatments on fatigue behaviour of notched LPBF AlSi10Mg: Experimental and deep learning approaches
Laser powder bed fusion (LPBF) as one of the widely used technologies of additive manufacturing (AM), has a high capability to produce complex geometries such as notched parts in a layer-by-layer manner. LPBF parts in their as built state have inhomogeneous and anisotropic microstructure and poor surface quality. Post-treatments can play a key role in modulating these imperfections. In this study, the effects of four different post-treatments including heat treatment, shot peening and electro-chemical polishing as well as their combination as hybrid treatment were investigated on microstructure, surface and mechanical properties and finally fatigue behaviour of the LPBF V-notched AlSi10Mg samples. Afterward, a deep learning based approach was employed for modelling the fatigue behaviour via artificial neural network. Surface roughness, surface modification factor, hardness, residual stress and porosities were considered as inputs and fatigue life was considered as the output. Model function of the network was generated and the relevant parametric and sensitivity analyses were performed. The results indicated the importance of surface related properties and the notable effect of the surface post-treatments in enhancing the fatigue performance of the LPBF material
Application of seismic attributes in structural study and fracture analysis of DQ oil field, Iran
The determination of the most unstable areas in oil fields is critical for addressing engineering problems of wellbore and sand production as well as geologic problems such as understanding dynamic constraints on hydrocarbon migration and fracture permeability. In this research work, coherency seismic attribute has been used for the determination of the most critical areas in terms of drilling stabilities in the DQ oil field, Iran. The results obtained have shown that the (1) predominant features are the SSE–NNW and N–S trends (2) the central part of the DQ structure shows the highest concentration of segment bundles, (3) the segment bundles seem to be aligned along some lineaments oriented SE–NW and SSE–NNW, and (4) on the eastern and western margins of the map there is an anomalous concentration of segments oriented E–W. It can be concluded that coherency attribute is a valuable tool for structural analysis highlighting those areas containing unstable features
Occult laryngeal foreign body mimicking normal thyroid cartilage
Introduction: Foreign body aspiration is common especially in children. The absence of history of choking does not rule out the diagnosis. Diagnosis required high index of suspicion. Case Presentation: Undiagnosed foreign body aspiration mostly occurs in bronchial airway rather than larynx and can cause severe complications. In this article, we report a silent laryngeal foreign body aspiration to show that careful history taking and accurate evaluation of radiography are important factors for diagnosis. Conclusions: The single most significant factor leading to detect of tracheobronchial foreign body aspiration is a high index of suspicion; this case highlights the possibility of a foreign body in the airway in patients who presents with a recent onset of chronic respiratory complaints. © 2015, Trauma Monthly
Epidemiological characteristics of human brucellosis in Shahin Dezh, Western Azarbaijan, Iran, 2008-2012
Background: Brucellosis is still one of the most challenging issues for health and the economy in many developing countries such as Iran. Objectives: This study investigated the epidemiological features of brucellosis in Shahin Dezh, Western Azarbaijan province, North West of Iran. Patients and Methods: This study had across-sectional design and data was collected from private and public sectors over a five-year period (2008-2012). All cases were studied between years 2008 and 2012 in Shahin Dezh. Results: In total, 492 cases of brucellosis were reported. The prevalence of brucellosis decreased from 152 cases/100000 inhabitants in 2008 to 97 cases/100000 inhabitants at the beginning of 2012. About 52.3 of subjects were male, and most cases of brucellosis were aged 25-30 years. Eighty-one percent of subjects lived in rural areas. There was a statistically significant difference regarding contact with livestock between rural and urban areas (91.7 vs. 68.8) (P value <0.001). Raw milk was the most commonly consumed dairy product; consumed by 37 of cases. Finally, during winter and spring a high prevalence rate of brucellosis was reported. Conclusions: Comprehensive health-related interventions need to empower communities at risk, especially young men and young and adult women in the Shahin Dezh County. Health education is needed to raise awareness of people in the studied area. © 2015, Infectious Diseases and Tropical Medicine Research Center
Phenotypic and genotypic characteristics of tetracycline resistant Acinetobacter baumannii isolates from nosocomial infections at Tehran hospitals
Objective(s): To date, the most important genes responsible for tetracycline resistance among Acinetobacter baumannii isolates have been identified as tet A and tet B. This study was carried out to determine the rate of resistance to tetracycline and related antibiotics, and mechanisms of resistance. Materials and Methods: During the years 2010 and 2011, a total of 100 A. baumannii isolates were recovered from patients in different hospitals of Tehran, Iran. Antimicrobial susceptibility to tetracycline, minocycline, doxicycline and tigecycline was evaluated by E-test. Polymerase chain reaction (PCR) of the tet A and tet B genes was performed using specific primers, after which the isolates were subjected to Repetitive Extragenic Palindromic-PCR (PCR) to identify the major genotypes. Results: Of all isolates, 89 were resistant to tetracycline (MIC50 = 32 mu g/ml, MIC90 = 512 mu g/ml). Minocycline with the resistant rate of 35 (MIC50 = 16 mu g/ml, MIC90 = 32 mu g/ml) and doxicycline with the resistant rate of 25 (MIC50 = 16 mu g/ml, MIC90= 32 mu g/ml) have a good activity against A. baumannii isolates. All isolates were sensitive to tigecycline. Frequencies of tet B and tet A genes and coexistence of tet A and tet B among the isolates resistant to tetracycline, were 87.6, 2.2 and 1.1, respectively. Distribution of REP-types among A. baumannii isolates was types A (40), B (30), C (10), D (5) and E (5). Conclusion: It seems that tet A and tet B genes play an important role in the induction of resistance towards tetracyclines used in this study. It is suggested that further studies focus on other antimicrobial drugs and combinations in order to achieve a successful therapy against multi drug resistance (MDR) A. baumannii strains in Iran
Generalized Grassmannian Coherent States For Pseudo-Hermitian Level Systems
The purpose of this paper is to generalize fermionic coherent states for
two-level systems described by pseudo-Hermitian Hamiltonian \cite{Trifonov}, to
n-level systems. Central to this task is the expression of the coherent states
in terms of generalized Grassmann variables. These kind of Grassmann coherent
states satisfy bi-overcompleteness condition instead of over-completeness one,
as it is reasonably expected because of the biorthonormality of the system.
Choosing an appropriate Grassmann weight function resolution of identity is
examined. Moreover Grassmannian coherent and squeezed states of deformed group
for three level pseudo-Hermitian system are presented.Comment: 17 page
Role and Function of KPC and MBL Enzymes in Increasing the Pathogenicity of Pseudomonas Aeruginosa Isolated from Burn Wounds
BACKGROUND AND OBJECTIVE: Pseudomonas aeruginosa is one of the main causes of hospital infections. Pathogenic factors in this bacterium may play a role in the resistance to carbapenem and beta-lactam. The purpose of this study was to evaluate the role and function of KPC and MBL enzymes in increasing the pathogenicity of Pseudomonas aeruginosa isolated from burn wounds.
METHODS: In this cross-sectional study, 63 isolates of Pseudomonas aeruginosa from burn wounds of different patients were isolated using biochemical tests such as fermentation of sugars in the OF medium, oxidase test, and so on. Determination of resistance pattern and strains with metallobetalactamase and carbapenema was done by disc diffusion method. The oprD gene was used for molecular confirmation of isolates. PCR method was used to detect pathogenicity genes.
FINDINGS: Out of 63 isolates of Pseudomonas aeruginosa isolated from burn patients, 10 isolates (15.83%) had KPC enzyme and 13 isolates (20.63%) had MBL enzymes. Doripenem, Ertapenem and meropenem were the most frequent. Also, the lasB gene was observed in 43 isolates (68.25%), plcN gene in 41 isolates (65.07%), lasA gene in 20 isolates (31.74%), apr in 60 isolates (95.23%), phzI gene in 53 isolates (84.12%), the phzII gene in 38 isolates (60.31%), phzH gene in 30 isolates (47.61%) and plcH gene in 56 isolates (88.88%).
CONCLUSION: The results of this study showed that the production of Carbapnemase and MBL enzymes increased the pathogenicity of Pseudomonas aeruginosa isolated from burn wounds
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