253 research outputs found

    Unmodifiable variables related to thyroid cancer incidence

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    The incidence of thyroid cancer is significantly different between male and female patients. Thyroid cancer is also the only form of cancer where age can be considered a staging variable. Identifying biological prognostic factors such as age or sex is important as it helps select an optimal personalized therapy. The present analysis is an observational, prospective study that enrolled all patients with thyroid disease who were operated upon at a single center. The study aimed to determine the most frequent age at presentation, the predominance of one sex over the other, the incidence of malignant thyroid disease, and the relative risk for each sex to develop thyroid carcinoma. The incidence of thyroid carcinoma was higher for women than for men, with a higher relative risk in the female subgroup. Incidence was also highest in the 50-60-year-old group. Given that studies show better survival for women and for younger patients, even when presenting with advanced disease, compared with older, male patients, such prognostic indicators should be a factor in the treatment decision

    Does sex of the patient play a role in survival for MSI colorectal cancer?

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    Microsatellite instability (MSI) is a feature of colorectal tumors that develops as a result of inactivation of the DNA mismatch repair system. It is found in about 15% of all colorectal cancers and is an important prognostic molecular marker when assessing patients with colorectal cancer. It can influence prognosis and treatment decisions in both the advanced and early stages. Although in early stages this marker suggests a favorable prognosis and presents an important argument against adjuvant treatment in stage II disease, in metastatic stages it no longer associated with such an optimistic outcome. The present trial is a prospective, single-center study which included 122 colorectal cancer patients who were tested for MSI using immunohistochemistry. The trial included patients with stage II to IV colorectal cancer, treated in the Prof. Dr. Agrippa Ionescu Emergency Hospital, Bucharest, Romania. Follow-up data were collected during a 24-month period. The study attempted to determine whether differences exist in overall survival for MSI (microsatellite instability) vs. MSS (microsatellite stable) colorectal cancer and to ascertain whether sex of the patient influences prognosis in MSI patients, irrespective of stage or treatment. Results demonstrated no significant differences in survival for MSI vs MSS colorectal patients, and patients’ gender proved not to influence the outcome in MSI patients

    Lattice-gas Monte Carlo study of adsorption in pores

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    A lattice gas model of adsorption inside cylindrical pores is evaluated with Monte Carlo simulations. The model incorporates two kinds of site: (a line of) ``axial'' sites and surrounding ``cylindrical shell'' sites, in ratio 1:7. The adsorption isotherms are calculated in either the grand canonical or canonical ensembles. At low temperature, there occur quasi-transitions that would be genuine thermodynamic transitions in mean-field theory. Comparison between the exact and mean-field theory results for the heat capacity and adsorption isotherms are provided

    Ionospheric control of the dawn‐dusk asymmetry of the Mars magnetotail current sheet

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    This study investigates the role of solar EUV intensity at controlling the location of the Mars magnetotail current sheet and the structure of the lobes. Four simulation results are examined from a multifluid magnetohydrodynamic model. The solar wind and interplanetary magnetic field (IMF) conditions are held constant, and the Mars crustal field sources are omitted from the simulation configuration. This isolates the influence of solar EUV. It is found that solar maximum conditions, regardless of season, result in a Venus‐like tail configuration with the current sheet shifted to the −Y (dawnside) direction. Solar minimum conditions result in a flipped tail configuration with the current sheet shifted to the +Y (duskside) direction. The lobes follow this pattern, with the current sheet shifting away from the larger lobe with the higher magnetic field magnitude. The physical process responsible for this solar EUV control of the magnetotail is the magnetization of the dayside ionosphere. During solar maximum, the ionosphere is relatively strong and the draped IMF field lines quickly slip past Mars. At solar minimum, the weaker ionosphere allows the draped IMF to move closer to the planet. These lower altitudes of the closest approach of the field line to Mars greatly hinder the day‐to‐night flow of magnetic flux. This results in a buildup of magnetic flux in the dawnside lobe as the S‐shaped topology on that side of the magnetosheath extends farther downtail. The study demonstrates that the Mars dayside ionosphere exerts significant control over the nightside induced magnetosphere of that planet.Plain Language SummaryMars, which does not have a strong magnetic field, has an induced magnetic environment from the draping of the interplanetary magnetic field from the Sun. It folds around Mars, forming two “lobes” of magnetic field behind the planet with a current sheet of electrified gas (plasma) behind it. The current sheet is not directly behind the planet but rather shifted toward the dawn or dusk direction. It is shown here that one factor controlling the location of the current sheet is the dayside ionosphere. At solar maximum, the ionosphere is dense, the magnetic field slips easily by the planet, and the current sheet is shifted toward dawn. At solar minimum, the ionosphere is relatively weak, the magnetic field slippage is slowed down, and the current sheet shifts toward dusk.Key PointsThere is a systematic Y (i.e., dawn‐dusk) asymmetry in the location of the Martian magnetotail current sheet in modified MSE coordinatesThe asymmetry is controlled by ionospheric conditions, shifting to the dawn (‐Y) during solar maximum and to the dusk during solar minimumThe shift found in this study is not a function of crustal fields, which were omitted, or solar wind conditions, which were held constantPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137681/1/jgra53609_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137681/2/jgra53609.pd

    Unmodifiable variables related to thyroid cancer incidence

    Get PDF
    The incidence of thyroid cancer is significantly different between male and female patients. Thyroid cancer is also the only form of cancer where age can be considered a staging variable. Identifying biological prognostic factors such as age or sex is important as it helps select an optimal personalized therapy. The present analysis is an observational, prospective study that enrolled all patients with thyroid disease who were operated upon at a single center. The study aimed to determine the most frequent age at presentation, the predominance of one sex over the other, the incidence of malignant thyroid disease, and the relative risk for each sex to develop thyroid carcinoma. The incidence of thyroid carcinoma was higher for women than for men, with a higher relative risk in the female subgroup. Incidence was also highest in the 50-60-year-old group. Given that studies show better survival for women and for younger patients, even when presenting with advanced disease, compared with older, male patients, such prognostic indicators should be a factor in the treatment decision

    Does sex of the patient play a role in survival for MSI colorectal cancer?

    Get PDF
    Microsatellite instability (MSI) is a feature of colorectal tumors that develops as a result of inactivation of the DNA mismatch repair system. It is found in about 15% of all colorectal cancers and is an important prognostic molecular marker when assessing patients with colorectal cancer. It can influence prognosis and treatment decisions in both the advanced and early stages. Although in early stages this marker suggests a favorable prognosis and presents an important argument against adjuvant treatment in stage II disease, in metastatic stages it no longer associated with such an optimistic outcome. The present trial is a prospective, single-center study which included 122 colorectal cancer patients who were tested for MSI using immunohistochemistry. The trial included patients with stage II to IV colorectal cancer, treated in the Prof. Dr. Agrippa Ionescu Emergency Hospital, Bucharest, Romania. Follow-up data were collected during a 24-month period. The study attempted to determine whether differences exist in overall survival for MSI (microsatellite instability) vs. MSS (microsatellite stable) colorectal cancer and to ascertain whether sex of the patient influences prognosis in MSI patients, irrespective of stage or treatment. Results demonstrated no significant differences in survival for MSI vs MSS colorectal patients, and patients’ gender proved not to influence the outcome in MSI patients

    Lattice model of gas condensation within nanopores

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    We explore the thermodynamic behavior of gases adsorbed within a nanopore. The theoretical description employs a simple lattice gas model, with two species of site, expected to describe various regimes of adsorption and condensation behavior. The model includes four hypothetical phases: a cylindrical shell phase (S), in which the sites close to the cylindrical wall are occupied, an axial phase (A), in which sites along the cylinder's axis are occupied, a full phase (F), in which all sites are occupied, and an empty phase (E). We obtain exact results at T=0 for the phase behavior, which is a function of the interactions present in any specific problem. We obtain the corresponding results at finite T from mean field theory. Finally, we examine the model's predicted phase behavior of some real gases adsorbed in nanopores

    Environmental effects on water intake and water intake prediction in growing beef cattle

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    Water is an essential nutrient, but there are few recent studies that evaluate how much water individual beef cattle consume and how environmental factors affect an individual’s water intake (WI). Most studies have focused on WI of whole pens rather than WI of individual animals. Thus, the objective of this study was to evaluate the impact of environmental parameters on individual-animal WI across different seasons and develop prediction equations to estimate WI, including within different environments and management protocols. Individual daily feed intake and WI records were collected on 579 crossbred steers for a 70-d period following a 21-d acclimation period for feed and water bunk training. Steers were fed in 5 separate groups over a 3-yr period from May 2014 to March 2017. Individual weights were collected every 14 d and weather data were retrieved from the Oklahoma Mesonet’s Stillwater station. Differences in WI as a percent of body weight (WI%) were analyzed accounting for average temperature (TAVG), relative humidity (HAVG), solar radiation (SRAD), and wind speed (WSPD). Seasonal (summer vs. winter) and management differences (ad libitum vs. slick bunk) were examined. Regression analysis was utilized to generate 5 WI prediction equations (overall, summer, winter, slick, and ad libitum). There were significant (P \u3c 0.05) differences in WI between all groups when no environmental parameters were included in the model. Although performance was more similar after accounting for all differences in weather variables, significant (P \u3c 0.05) seasonal and feed management differences were still observed for WI%, but were less than 0.75% of steer body weight. The best linear predictors of daily WI (DWI) were dry mater intake (DMI), metabolic body weights (MWTS), TAVG, SRAD, HAVG, and WSPD. Slight differences in the coefficient of determinations for the various models were observed for the summer (0.34), winter (0.39), ad libitum (0.385), slick bunk (0.41), and overall models (0.40). Based on the moderate R2 values for the WI prediction equations, individual DWI can be predicted with reasonable accuracy based on the environmental conditions that are present, MWTS, and DMI consumed, but substantial variation exists in individual animal WI that is not accounted for by these models

    Left ventricular global longitudinal strain in bicupsid aortic valve patients: head-to-head comparison between computed tomography, 4D flow cardiovascular magnetic resonance and speckle-tracking echocardiography

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    Left ventricular global longitudinal strain (LVGLS) analysis is a sensitive measurement of myocardial deformation most often done using speckle-tracking transthoracic echocardiography (TTE). We propose a novel approach to measure LVGLS using feature-tracking software on the magnitude dataset of 4D flow cardiovascular magnetic resonance (CMR) and compare it to dynamic computed tomography (CT) and speckle tracking TTE derived measurements. In this prospective cohort study 59 consecutive adult patients with a bicuspid aortic valve (BAV) were included. The study protocol consisted of TTE, CT, and CMR on the same day. Image analysis was done using dedicated feature-tracking (4D flow CMR and CT) and speckle-tracking (TTE) software, on apical 2-, 3-, and 4-chamber long-axis multiplanar reconstructions (4D flow CMR and CT) or standard apical 2-, 3-, and 4-chamber acquisitions (TTE). CMR and CT GLS analysis was feasible in all patients. Good correlations were observed for GLS measured by CMR (− 21 ± 3%) and CT (− 20 ± 3%) versus TTE (− 20 ± 3%, Pearson’s r: 0.67 and 0.65, p 0.61, p < 0.001). Feature-tracking GLS analysis is feasible using the magnitude images acquired with 4D flow CMR. GLS measurement by CMR correlates well with CT and speckle-tracking 2D TTE. GLS analysis on 4D flow CMR allows for an integrative approach, integrating flow and functional data in a single sequence. Not applicable, observational study

    Differences in Nutrient Requirements Imply a Non-Linear Emergence of Leaders in Animal Groups

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    Collective decision making and especially leadership in groups are among the most studied topics in natural, social, and political sciences. Previous studies have shown that some individuals are more likely to be leaders because of their social power or the pertinent information they possess. One challenge for all group members, however, is to satisfy their needs. In many situations, we do not yet know how individuals within groups distribute leadership decisions between themselves in order to satisfy time-varying individual requirements. To gain insight into this problem, we build a dynamic model where group members have to satisfy different needs but are not aware of each other's needs. Data about needs of animals come from real data observed in macaques. Several studies showed that a collective movement may be initiated by a single individual. This individual may be the dominant one, the oldest one, but also the one having the highest physiological needs. In our model, the individual with the lowest reserve initiates movements and decides for all its conspecifics. This simple rule leads to a viable decision-making system where all individuals may lead the group at one moment and thus suit their requirements. However, a single individual becomes the leader in 38% to 95% of cases and the leadership is unequally (according to an exponential law) distributed according to the heterogeneity of needs in the group. The results showed that this non-linearity emerges when one group member reaches physiological requirements, mainly the nutrient ones – protein, energy and water depending on weight - superior to those of its conspecifics. This amplification may explain why some leaders could appear in animal groups without any despotism, complex signalling, or developed cognitive ability
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