328 research outputs found
STR-925: BONDING BEHAVIOR IN BRIDGE STEEL-REINFORCED ELASTOMERIC ISOLATORS
Steel-reinforced elastomeric isolators (SREIs) have been shown to be efficient devices to protect structures against moderate and severe earthquakes by isolating them from ground motions. Bridge elastomeric isolators, however, deteriorate when undergone repetitive loading cycles due to either earthquakes or traffic loadings. One major damage type observed dominantly in these devices is delamination or de-bonding between rubber and supporting plates and steel reinforcements, if cold-bonded. This paper investigates potential damage scenarios likely to occur in cold-bonded bridge SREIs. It also looks into bonding properties of rubber and steel in tension and shear, the two important functional characteristics of elastomeric isolators. In this study, experimental tests are employed in order to observe the bonding behavior between rubber and steel. Damage states have been organized and it is observed that the adhesive properties and level of shear deformations govern bonding characteristics
Can hand dexterity predict the disability status of patients with multiple sclerosis?
Background: Multiple Sclerosis (MS) is the most common disabling neurological disease. Hand dysfunction is one of the main complaints of patients with MS. The present study aimed to compare hand dexterity of MS patients with low Expanded Disability Status Scale (EDSS) scores and healthy adults. It also sought to identify the predictors of disability status of patients with MS based on their manual dexterity and demographic characteristics. Methods: In this cross-sectional study, 60 (16 male/44 female) patients with MS and 60 (19 male/41 female) healthy people, who matched in terms of age and sex, were recruited. Their hand dexterity was evaluated by the Purdue Pegboard Test. The disability status of the MS group was determined by the Expanded Disability Status Scale. The data were analyzed using SPSS15. Results: The hand dexterity in MS group even with low EDSS score (1.5 ñ 1.07) was weaker than control group. Moreover, the dexterity of dominant hand and alternating two hands coordination subtests of the PPT was a good discriminator between two groups (p<0.001). The results of linear regression analysis suggested dominant hand dexterity and disease duration as predictors of disability status that predict 60.5 per cent of the variation in EDSS scores in patients with MS (p<0.001). Conclusion: Reduced dominant hand dexterity in patients with MS is a disabling factor. Further research is recommended to determine if early hand rehabilitation can reduce the severity of disability in Patients with MS
The miR-196a SNP Rs11614913 but not the miR-499 rs37464444 SNP is a risk factor for non-small cell lung cancer in an Iranian population
BACKGROUND: Globally, lung cancer represents a major cause of cancer-related deaths. The regulation of gene expression is modulated by small noncoding RNAs called miRNAs that can act as both tumor suppressors and oncogenes. The maturation, expression and binding to target mRNAs is affected by single nucleotide polymorphisms (SNPs) in miRNA genomic regions thereby contributing to cancer susceptibility. SNPs Rs11614913 in miR196a and Rs3746444 in miR-499 are implicated in the development of cancers such as non-small cell lung cancer (NSCLC) in non-Arabic subjects. MATERIALS AND METHODS: A small cohort of 204 participants including 104 lung cancer patients and 100 non-cancer controls subjects were enrolled into the study. The allele frequencies were determined by Polymerase Chain Reaction- Restriction Fragment Length Polymorphism (PCR-RFLP) and their correlation with lung cancer risk was determined. RESULTS: The miR-196a rs11614913 polymorphism increased the risk of NSCLC (CC vs. TT+TC: OR= 2.26, 95%CI= 1.28 - 3.98, P= 0.0046) in a dominant genetic model. No statistically significant association was found between the miR-499 rs37464444 polymorphism and NSCLC. CONCLUSION: The rs11614913 polymorphism in miR-196a, but not the miR-499 rs37464444 polymorphism, increased the risk of NSCLC. Further studies with larger sample sizes in correlation with functional outcomes at the cellular level should be undertaken
Evaluation of Content and Accessibility of Orthopaedic Trauma Fellowship Websites
Background: Residents frequently use the internet to find material on fellowship programs. The Orthopaedic Trauma Association (OTA) website serves as a central hub for information on an orthopaedic trauma fellowship (OTF). This study aims to evaluate the accessibility, content, and perceived importance of OTF websites.
Methods: We reviewed the 49 OTFs accredited by the OTA fellowship database as of January 2014. We searched for corresponding OTF websites by using the provided OTA hyperlinks and conducting a separate Google search of program location and institution. Links to websites of general orthopaedic programs were not counted. Content of OTF websites was analyzed by noting the presence or absence of specific items in fellow education (11 items) and recruitment (5 items).
Results: Of 49 OTFs, a total of 39 (80%) websites specific to the fellowship were identified by searching the OTA database and Google browser. Seven (14%) programs listed on the OTA database provided links directly to fellowship programs. Most programs (28; 57%) did not provide links to specific OTFs or provided non-functional links on the OTA website. Of the 39 accessible OTF websites, a total of 24 (61%) had complete information regarding recruitment and 14 (36%) provided complete details on education.
Conclusions: Most accredited OTFs do not adequately use the internet to provide easily accessible and complete information. Further details (especially regarding the role, education, and schedule) would help prospective candidates in thoroughly evaluating programs. The discrepancy in content and accessibility can hinder prospective fellows from appropriately investigating fellowship programs
Mechanisms Associated with Daytime and Nighttime Heat Waves over the United States
Heat waves are extreme climate events that have the potential to cause immense stress on human health, agriculture and energy systems, so understanding the processes leading to their onset is crucial. There is no single accepted definition for heat waves, but they are generally described as a sustained amount of time where temperature exceeds a local threshold. Multiple different temperature variables are potentially relevant, as high values of daily maximum (T(max)) and minimum (T(min)) temperatures can both be detrimental to human health. Previous studies have concluded that the frequency of global heat waves has increased over recent decades, with greater increases in T(min)- than T(max)-heat waves in several regions. In this study, we focus explicitly on the different mechanisms associated with heatwaves manifest during daytime versus nighttime hours over the United States. Heat waves are examined using the National Aeronautics and Space Administration (NASA) Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2). A daytime (nighttime) heat wave is defined as average daytime (nighttime) temperature exceeding its calendar day 90th percentile for at least 3 days. Over 1980-2018, the number of heat wave days per summer has increased over much of the United States. Trends are stronger for nighttime versus daytime heat wave frequency over the Northeast, Midwest and Southwest United States. Local and remote processes linked with daytime and nighttime heat waves are identified through composite analysis of clouds, precipitation, soil moisture, and fluxes of heat and moisture. Finally, we characterize the large-scale atmospheric circulation associated with daytime and nighttime heat waves over different regions of the United States
Integrated control of Protapion trifolii (Col.: Apionidae) and its effect on yield component of Berseem clover in Khuzestan province
This experiment was conducted in Safiabad Agricultural Research Center for two years starting from 7th October 2001 in order to evaluate and selection of the best cultural, chemical and integrated control methods of Protapion trifolii (L.) (Col.: Apionidae) in Berseem clover. The effects of control methods were investigated using 9 experimental treatments (including chemical and cultural controls, and the integration of these two methods) in the form of a 2-factor split plot design with 3 replications. Vertical factors were two insecticides, Ecamet and Durseban, and an "untreated" treatment, and horizontal factors were the dates of second mowing (for seed) in 1st, 16th & 31st March 2002. In order to evaluate the amount of damage and the effects of different control methods on yield components, the percentage of inflorescence infestation to larvae before and after spraying, the amount of seed yield, the number of seeds per inflorescence, the number of inflorescences per m2, 1000 seeds weight, the amount of fresh forage, dry forage and the amount of produced protein were recorded. The results of two years combined analysis showed no significant difference among spraying treatments for all the mentioned characteristics, except the percent of larvae infested inflorescences after spraying. Contrary to spraying treatments, there were significant differences among mowing treatments for the percent of larvae infested inflorescences before spraying, the amount of seed yield, the number of inflorescences per m2, the amount of fresh forage, dry forage and the amount of produced protein. Considering the main objective of this experiment (obtaining the highest seed yield) and the high economic value of the clover seeds, the results showed that the mowing date of 16th March 2002 could be suggested as the best date. Also, the chemical control of P. trifolii had no significant effect on seed yield despite its effect on the population of the pest itself, so probably the chemical control of this pest in seed farms of Berseem clover has no economic justification in addition to its harmful environmental effects
Perfluorooctanoic acid exposure assessment on common carp liver through image and ultrastructural investigation
Perfluorooctanoic acid (PFOA) poses particular concern as an emerging pollutant in both surface and ground waters. Fish, as a natural inhabitant of these waters and being highly representative of vertebrates, represents an ideal animal model to assess the toxic effects of PFOA. Hereby, liver microscopic texture was comparatively evaluated in individuals of common carp subchronically exposed to PFOA using grayscale differential box counting, a fractal analysis method. Furthermore, liver cytoplasmic glycogen areas and ultrastructure were also evaluated and compared to the image analysis findings. Redundancy Analysis was performed to assess, in summary, how much the variation of fractal dimension and lacunarity was explained by the concentration of PFOA in liver, the mass of liver and the number of proliferating cell nuclear antigen (PCNA)-immunoreactive nuclei. Treatment group ordination was better determined by fractal dimension than lacunarity. Interestingly, a significant complexity increase was associated with the modification of liver microscopic texture due to PFOA exposure. This complexity increase was related to âcloudy swellingâ, possibly representing a primarily adaptive strategy against PFOA challenge, rather than a slight, reversible form of degeneration as traditionally proposed. The occurrence of endoplasmic reticulum stress, unfolded protein reaction and hormetic response was proposed and discussed
Does a New Modification of the Two-Step Injection Technique for Inferior Alveolar Nerve Block Reduce Pain Compared to the Conventional Technique? A Randomized Clinical Trial
Background. The ability to control pain is an essential part of dental procedures and the need for optimal pain control and reduction of discomfort is the primary concern of every dentist. This study aims to compare the pain and vital signs during inferior alveolar nerve block between conventional and a new modification of the two-step injection techniques. Methods. In this institutional single-blind randomized clinical trial, attendees of dental school at Mazandaran University of Medical Sciences from February to May 2022 were included. Inclusion criteria were 20-60 years old and healthy (ASA1) individuals who were willing to participate in this study. Individuals who were taking medications affecting their understanding of pain and patients with active infections at the injection site were excluded. These individuals were divided into two groups. First, superficial anesthesia was performed and afterward, conventional and two-step injection techniques were performed. For the two-step injection method, 6 mm of the needle was injected into the mucosa and one-third of the local anesthetic solution was released from the computer-controlled injection toolkit. Afterward, a 25 mm 30-gauge needle was reinserted into the previous hole delivering the remaining local anesthetic. The pain during injection was measured by a patient-reported numerical rating scale (NRS). Moreover, vital signs were monitored immediately before and after the injection. Kolmogorov-Smirnov test, Mann-Whitney U test, independent T-test, and Fisher's exact Ï2 test were performed for statistical analysis (α = 0.05). Results. This study involved 32 adults aged between 20 and 50 years old with 1: 1 female/male sex distribution. The pain score was significantly higher in the conventional injection technique compared to the two-step injection technique in all sex and age groups. There were no significant differences in vital signs between the conventional and two-step injection techniques. There was no significant difference in the mean pain scores of females and males, regardless of their injection techniques. Conclusion. Utilizing the two-step injection technique in patients for inferior alveolar block reduces pain during injection without altering patients' vital signs significantly. This trial is registered with IRCT20220106053646N1
Identifying key water resource vulnerabilities in dataâscarce transboundary river basins
This paper presents a twoâstep framework to identify key water resource vulnerabilities in transboundary river basins where data availability on both hydrological fluxes and the operation of manâmade facilities is either limited or nonexistent. In a first step, it combines two stateâofâtheâart modeling tools to overcome data limitations and build a model that provides a lower bound on risks estimated in that basin. Land data assimilation (processâbased hydrological modeling taking remoteâsensed products as inputs) is needed to evaluate hydrological fluxes, that is, streamflow data and consumptive use in irrigated agricultureâa lowerâend estimate of demand. Hydroeconomic modeling provides cooperative water allocation policies that reflect the bestâcase management of storage capacity under hydrological uncertainty at a monthly time step for competing usesâhydropower, irrigation. In a second step, the framework uses additional scenarios to proceed with the inâdepth analysis of the vulnerabilities identified despite the use of what is by definition a bestâcase model. We implement this approach to the TigrisâEuphrates river basin, a politically unstable region where water scarcity has been hypothesized to serve as a trigger for the Syrian revolution and ensuing war. Results suggest that even under the framework's bestâcase assumptions, the Euphrates part of the basin is close to a threshold where it becomes reliant on transfers of saline water from other parts of the basin to ensure irrigation demands are met. This TigrisâEuphrates river basin application demonstrates how the proposed framework quantifies vulnerabilities that have been hitherto discussed in a mostly qualitative, speculative way
Enteric neuromodulators and mucus discharge in a fish infected with the intestinal helminth Pomphorhynchus laevis
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