1,830 research outputs found

    Improvement of Low Traffic Volume Gravel Roads in Nebraska

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    In the state of Nebraska, over one-third of roadways are unpaved, and consequently require a significant amount of financial and operational resources to maintain their operation. Undesired behavior of surface gravel aggregates and the road surfaces can include rutting, corrugation, and ponding that may lead to reduced driving safety, speed or network efficiency, and fuel economy. This study evaluates the parameters that characterize the performance and condition of gravel roads overtime period related to various aggregate mix designs. The parameters, including width, slope, and crown profiles, are examples of performance criteria. As remote sensing technologies have advanced in the recent decade, various techniques have been introduced to collect high quality, accurate, and dense data efficiently that can be used for roadway performance assessments. Within this study, two remote sensing platforms, including an unpiloted aerial system (UAS) and ground-based lidar scanner, were used to collect point cloud data of selected roadway sites with various mix design constituents and further processed for digital assessments. Within the assessment process, statistical parameters such as standard deviation, mean value, and coefficient of variance are calculated for the extracted crown profiles. In addition, the study demonstrated that the point clouds obtained from both lidar scanners and UAS derived SfM can be used to characterize the roadway geometry accurately and extract critical information accurately

    Layer-By-Layer Assembly of Graphene Oxide on Thermosensitive Liposomes for Photo-Chemotherapy

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    Stimuli responsive polyelectrolyte nanoparticles have been developed for chemo-photothermal destruction of breast cancer cells. This novel system, called layer by layer Lipo-graph (LBL Lipo-graph), is composed of alternate layers of graphene oxide (GO) and graphene oxide conjugated poly (l-lysine) (GO-PLL) deposited on cationic liposomesencapsulating doxorubicin. Various concentrations of GO and GO-PLL were examined and the optimal LBL Lipo-graph was found to have a particle size of 267.9 ± 13 nm, zeta potentialof +43.9 ± 6.9 mV and encapsulation efficiency of 86.4 ± 4.7%. The morphology of LBL Lipo-graph was examined by cryogenic-transmission electron microscopy (Cryo-TEM), atomic force microcopy (AFM) and scanning electron microscopy (SEM). The buildup of LBL Lipo-graph was confirmed via ultraviolet-visible (UV–Vis) spectrophotometry, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis. Infra-red (IR) response suggests that four layers are sufficient to induce a gel-to-liquid phase transition in response to near infra-red (NIR) laser irradiation. Light-matter interaction of LBL Lipo-graph was studied by calculating the absorption cross section in the frequency domain by utilizing Fourier analysis. Drug release assay indicates that the LBL Lipo-graph releases much faster in an acidic environment than a liposome control. A cytotoxicity assay was conducted to prove the efficacy of LBL Lipo-graph to destroy MD-MB-231 cells in response to NIR laser emission. Also, image stream flow cytometry and two photon microcopy provide supportive data for the potential application of LBL Lipo-graph for photothermal therapy. Study results suggest the novel dual-sensitive nanoparticles allow intracellular doxorubin delivery and respond to either acidic environments or NIR excitation. Statement of Significance Stimuli sensitive hybrid nanoparticles have been synthesized using a layer-by-layer technique and demonstrated for dual chemo-photothermal destruction of breast cancer cells. The hybrid nanoparticles are composed of alternating layers of graphene oxide and graphene oxide conjugated poly-l-lysine coating the surface of a thermosensitive cationic liposome containing doxorubicin as a core. Data suggests that the hybrid nanoparticles may offer many advantages for chemo-photothermal therapy. Advantages include a decrease of the initial burst release which may result in the reduction in systemic toxicity, increase in pH responsivity around the tumor environment and improved NIR light absorption

    Health literacy and its influencing factors in Iranian diabetic patients

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    Acknowledgements We would like to present our special thanks to all participants of this study. This study was supported by the Institute of Endocrinology and Metabolism (IEM) in Iran University of Medical Sciences.Peer reviewedPublisher PD

    Structural Identification of an 18-Story RC Building in Nepal Using Post-Earthquake Ambient Vibration and Lidar Data

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    Few studies have been conducted to systematically assess post-earthquake condition of structures using vibration measurements. This paper presents system identification and finite element (FE) modeling of an 18-story apartment building that was damaged during the 2015 Gorkha earthquake and its aftershocks in Nepal. In June 2015, a few months after the earthquake, the authors visited the building and recorded the building’s ambient acceleration response. The recorded data are analyzed, and the modal parameters of the structure are identified using an output-only system identification method. A linear FE model of the building is also developed to estimate numerically its dynamic properties. The identified modal parameters are compared to those of the model to identify possible shortcomings of the modeling and identification approaches. The identified natural frequencies and mode shapes for two of the three closely spaced vibration modes in the lower frequency range of interest (0.2–1.0 Hz) are in good agreement with the numerical model. The model is used to estimate the response of the building to the nearby recorded ground motion due to earthquake and the main aftershock. The maximum drift ratios are compared to the observed damage in the building and surface defects detected and quantified by the lidar scans as the research team performed a series of light detection and ranging (lidar) scans from interior of selected floors to document the damage patterns along the height of the building

    Identification of disease-causing genes using microarray data mining and gene ontology

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    Background: One of the best and most accurate methods for identifying disease-causing genes is monitoring gene expression values in different samples using microarray technology. One of the shortcomings of microarray data is that they provide a small quantity of samples with respect to the number of genes. This problem reduces the classification accuracy of the methods, so gene selection is essential to improve the predictive accuracy and to identify potential marker genes for a disease. Among numerous existing methods for gene selection, support vector machine-based recursive feature elimination (SVMRFE) has become one of the leading methods, but its performance can be reduced because of the small sample size, noisy data and the fact that the method does not remove redundant genes. Methods: We propose a novel framework for gene selection which uses the advantageous features of conventional methods and addresses their weaknesses. In fact, we have combined the Fisher method and SVMRFE to utilize the advantages of a filtering method as well as an embedded method. Furthermore, we have added a redundancy reduction stage to address the weakness of the Fisher method and SVMRFE. In addition to gene expression values, the proposed method uses Gene Ontology which is a reliable source of information on genes. The use of Gene Ontology can compensate, in part, for the limitations of microarrays, such as having a small number of samples and erroneous measurement results. Results: The proposed method has been applied to colon, Diffuse Large B-Cell Lymphoma (DLBCL) and prostate cancer datasets. The empirical results show that our method has improved classification performance in terms of accuracy, sensitivity and specificity. In addition, the study of the molecular function of selected genes strengthened the hypothesis that these genes are involved in the process of cancer growth. Conclusions: The proposed method addresses the weakness of conventional methods by adding a redundancy reduction stage and utilizing Gene Ontology information. It predicts marker genes for colon, DLBCL and prostate cancer with a high accuracy. The predictions made in this study can serve as a list of candidates for subsequent wet-lab verification and might help in the search for a cure for cancers

    Equilibrium conditions for semi-clathrate hydrates formed with CO2, N2 or CH4 in the presence of tri-n-butylphosphine oxide

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    We measured the thermodynamic stability conditions for the N, CO, or CH semiclathrate hydrate formed from the aqueous solution of tri-n-butylphosphine oxide (TBPO) at 26 wt %, corresponding to the stoichiometric composition for TBPO·34.5HO. The measurements were performed in the temperature range 283.71-300.34 K and pressure range 0.35-19.43 MPa with the use of an isochoric equilibrium step-heating pressure-search method. The results showed that the presence of TBPO made these semiclathrate hydrates much more stable than the corresponding pure N , CO, and CH hydrates. At a given temperature, the semiclathrate hydrate of 26 wt % TBPO solution + CH was more stable than that of 26 wt % TBPO solution + CO, which in turn was more stable than that of 26 wt % TBPO solution + N. We analyzed the phase equilibrium data using the Clausius-Clapeyron equation and found that, in the pressure range 0-20 MPa, the mean dissociation enthalpies for the semiclathrate hydrate systems of 26 wt % TBPO solution + N, 26 wt % TBPO solution + CO, and 26 wt % TBPO solution + CH were 177.75, 206.23, and 159.00 kJ·mol, respectively

    A Novel Mouse Fgfr2 Mutant, Hobbyhorse (hob), Exhibits Complete XY Gonadal Sex Reversal

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    The secreted molecule fibroblast growth factor 9 (FGF9) plays a critical role in testis determination in the mouse. In embryonic gonadal somatic cells it is required for maintenance of SOX9 expression, a key determinant of Sertoli cell fate. Conditional gene targeting studies have identified FGFR2 as the main gonadal receptor for FGF9 during sex determination. However, such studies can be complicated by inefficient and variable deletion of floxed alleles, depending on the choice of Cre deleter strain. Here, we report a novel, constitutive allele of Fgfr2, hobbyhorse (hob), which was identified in an ENU-based forward genetic screen for novel testis-determining loci. Fgr2hob is caused by a C to T mutation in the invariant exon 7, resulting in a polypeptide with a mis-sense mutation at position 263 (Pro263Ser) in the third extracellular immunoglobulin-like domain of FGFR2. Mutant homozygous embryos show severe limb and lung defects and, when on the sensitised C57BL/6J (B6) genetic background, undergo complete XY gonadal sex reversal associated with failure to maintain expression of Sox9. Genetic crosses employing a null mutant of Fgfr2 suggest that Fgr2hob is a hypomorphic allele, affecting both the FGFR2b and FGFR2c splice isoforms of the receptor. We exploited the consistent phenotype of this constitutive mutant by analysing MAPK signalling at the sex-determining stage of gonad development, but no significant abnormalities in mutant embryos were detected

    Service quality of private hospitals: The Iranian Patients' perspective

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    <p>Abstract</p> <p>Background</p> <p>Highly competitive market in the private hospital industry has caused increasing pressure on them to provide services with higher quality. The aim of this study was to determine the different dimensions of the service quality in the private hospitals of Iran and evaluating the service quality from the patients' perspective.</p> <p>Methods</p> <p>A cross-sectional study was conducted between October and November 2010 in Tehran, Iran. The study sample was composed of 983 patients randomly selected from 8 private general hospitals. The study questionnaire was the SERVQUAL questionnaire, consisting of 21 items in service quality dimensions.</p> <p>Results</p> <p>The result of factor analysis revealed 3 factors, explaining 69% of the total variance. The total mean score of patients' expectation and perception was 4.91(SD = 0.2) and 4.02(SD = 0.6), respectively. The highest expectation and perception related to the tangibles dimension and the lowest expectation and perception related to the empathy dimension. The differences between perception and expectation were significant (p < 0.001). There was a significant difference between the expectations scores based on gender, education level, and previous hospitalization in that same hospital. Also, there was a significant difference between the perception scores based on insurance coverage, average length of stay, and patients' health conditions on discharge.</p> <p>Conclusion</p> <p>The results showed that SERVQUAL is a valid, reliable, and flexible instrument to monitor and measure the quality of the services in private hospitals of Iran. Our findings clarified the importance of creating a strong relationship between patients and the hospital practitioners/personnel and the need for hospital staff to be responsive, credible, and empathetic when dealing with patients.</p

    Nutrition and lung cancer: a case control study in Iran

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    Background: Despite many prospective and retrospective studies about the association of dietary habit and lung cancer, the topic still remains controversial. So, this study aims to investigate the association of lung cancer with dietary factors. Method: In this study 242 lung cancer patients and their 484 matched controls on age, sex, and place of residence were enrolled between October 2002 to 2005. Trained physicians interviewed all participants with standardized questionnaires. The middle and upper third consumer groups were compared to the lower third according to the distribution in controls unless the linear trend was significant across exposure groups. Result: Conditional logistic regression was used to evaluate the association with lung cancer. In a multivariate analysis fruit (Ptrend < 0.0001), vegetable (P = 0.001) and sunflower oil (P = 0.006) remained as protective factors and rice (P = 0.008), bread (Ptrend = 0.04), liver (P = 0.004), butter (Ptrend = 0.04), white cheese (Ptrend < 0.0001), beef (Ptrend = 0.005), vegetable ghee (P < 0.0001) and, animal ghee (P = 0.015) remained as risk factors of lung cancer. Generally, we found positive trend between consumption of beef (P = 0.002), bread (P < 0.0001), and dairy products (P < 0.0001) with lung cancer. In contrast, only fruits were inversely related to lung cancer (P < 0.0001). Conclusion: It seems that vegetables, fruits, and sunflower oil could be protective factors and bread, rice, beef, liver, dairy products, vegetable ghee, and animal ghee found to be possible risk factors for the development of lung cancer in Iran

    Nationwide Prevalence of Diabetes and Prediabetes and Associated Risk Factors Among Iranian Adults: Analysis of Data from PERSIAN Cohort Study

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    Introduction Over the past decades prevalence of diabetes has increased in Iran and other countries. This study aimed to update the prevalence of diabetes and prediabetes in Iran and to determine associated sociodemographic risk factors, as well as diabetes awareness and control. Methods This is a nationally representative cross-sectional survey that included 163,770 Iranian adults aged 35-70 years, from different ethnic backgrounds, between 2014 and 2020. Diabetes was diagnosed at fasting blood sugar of >= 6.99 mmol/L (126 mg/dL), or receiving blood glucose-lowering treatment. Multivariable logistic regression was applied to detect determinants associated with prevalence of diabetes and prediabetes, as well as predictors of diabetes awareness and glycemic control. Results Sex- and age-standardized prevalence of diabetes and prediabetes was 15.0% (95% CI 12.6-17.3) and 25.4% (18.6-32.1), respectively. Among patients with diabetes, 79.6% (76.2-82.9) were aware of their diabetes. Glycemic control was achieved in 41.2% (37.5-44.8) of patients who received treatment. Older age, obesity, high waist to hip ratio (WHR), and specific ethnic background were associated with a significant risk of diabetes and prediabetes. Higher awareness of diabetes was observed in older patients, married individuals, those with high WHR, and individuals with high wealth score. Moreover, glycemic control was significantly better in women, obese individuals, those with high physical activity, educational attainment, and specific ethnic background. Conclusions The prevalence of diabetes and prediabetes is increasing at an alarming rate in Iranian adults. High proportion of uncontrolled patients require particular initiatives to be integrated in the health care system
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