nils-herrmann/clean_scirepeval huggingface dataset:
Phase Delay and Attenuation Corrections in Fourier Transform Nmr Tomographic Imaging

Applications of Fourier transform Nuclear Magnetic Resonance(NMR) to the field of tomographic imaging have become one of the important areas in biomedical imaging. NMR tomography, however, is low sensitivity imaging technique and the sensitivity is closely related to the static magnetic field strength applied to the object. Since the SNR (signal to noise ratio) of NMR imaging is proportional to Ho3/2, a higher magnetic field is a most desirable feature in NMR imaging. For a higher magnetic field, however, the frequency of r.f. signals for both excitation and detection is higher, which results in several undesirable effects such as phase delay and attenuation in the object. In this paper, we have proposed phase and attenuation dependent artifact correction based on the solution of the wave equation for a simple cylindrical model. Results of computer simulations and experiments are demonstrated.

Field of study: Physics
Using number of failed contact attempts to adjust for non‐ignorable non‐response

We present a general method of adjustment for non-ignorable non-response in studies where one or more further attempts are made to contact initial non-responders. A logistic regression model relates the probability of response at each contact attempt to covariates and outcomes of interest. We assume that the effect of these covariates and outcomes on the probability of response is the same at all contact attempts. Knowledge of the number of contact attempts enables estimation of the model by using only information from the respondents and the number of non-responders.Three approaches for fitting the response models and estimating parameters of substantive interest and their standard errors are compared: a modified conditional likelihood method in which the fitted inverse probabilities of response are used in weighted analyses for the outcomes of interest, an EM procedure with the Louis formula and a Bayesian approach using Markov chain Monte Carlo methods. We further propose the creation of several sets of weights to incorporate uncertainty in the probability weights in subsequent analyses. Our methods are applied as a sensitivity analysis to a postal survey of symptoms in Persian Gulf War veterans and other servicemen.

Field of study: Mathematics
Sensitivity to reinforcer duration in a self-control procedure.

In a concurrent-chains procedure, pigeons' responses on left and right keys were followed by reinforcers of different durations at different delays following the choice responses. Three pairs of reinforcer delays were arranged in each session, and reinforcer durations were varied over conditions. In Experiment 1 reinforcer delays were unequal, and in Experiment 2 reinforcer delays were equal. In Experiment 1 preference reversal was demonstrated in that an immediate short reinforcer was chosen more frequently than a longer reinforcer delayed 6 s from the choice, whereas the longer reinforcer was chosen more frequently when delays to both reinforcers were lengthened. In both experiments, choice responding was more sensitive to variations in reinforcer duration at overall longer reinforcer delays than at overall shorter reinforcer delays, independently of whether fixed-interval or variable-interval schedules were arranged in the choice phase. We concluded that preference reversal results from a change in sensitivity of choice responding to ratios of reinforcer duration as the delays to both reinforcers are lengthened.

Field of study: Biology, Psychology
A Empirical Study on Effects of the University Comprehensive Quality Appraisal to Volunteering of College Students

The university comprehensive quality appraisal is the important part of higher education management institutions,which is significant for college students to apply for awards.Especially volunteering is one of the key indicators of the comprehensive quality appraisal.Based on the assumption that the comprehensive quality appraisal institution will induce volunteering of college students,this paper explores effects of the university comprehensive quality appraisal to volunteering of college students with quantitative analysis.It has been testified that the university comprehensive quality appraisal could induce volunteering of college students.The cognition and identity of college students to the university comprehensive quality appraisal are the two main sides.The result shows that the more cognition and identity to the comprehensive quality appraisal,the more volunteering that college students involve.

Field of study: Education
Conductivity modification in polymer electrolyte–crown ether complexes

Polymer electrolyte (PEO:NH 4 I) has been complexed with dibenzo-24-crown-8 ether (DB24C8). The conductivity of the complexes has been measured as a function of the crown ether composition. The conductivity of this system is an order of magnitude higher than for the PEO:NH 4 I system. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) have been done to know about the thermal behaviour of the complexes. The conformational changes have been detected by Fourier transform infrared (FTIR) spectroscopy. Conductivity modification in the complexes has been explained by the chain-like formation in the complexes, increased amorphous phase and the enhanced free volume determined by positron annihilation lifetime spectroscopy (PALS).

Field of study: Materials science
NH3 in the Galactic Center is Formed under Cool Conditions

It is an open question why the temperature of molecular gas in the Galactic center region is higher than that of dust. To address this problem, we made simultaneous observations in the NH3 (J,K) = (1,1), (2,2), and (3,3) lines of the central molecular zone (CMZ) using the Kagoshima 6 m telescope. The ortho-to-para ratio of NH3 molecules in the CMZ is 1.5–3.5 at most observed area. This ratio is higher than the statistical equilibrium value, and suggests that the formation temperature of NH3 is 11–20 K. This temperature is similar to the dust temperature estimated from the submillimeter and infrared continuum. This result suggests that the NH3 molecules in the CMZ were produced on dust grains with the currently observed temperature (11–20 K), and they were released into the gas phase by supernova shocks or collisions of dust particles. The discrepancy between warm molecular gas and cold dust can be explained by the transient heating of the interstellar media in the CMZ approximately 10 5 years ago when the NH3 molecules were released from the dust.

Field of study: Physics
Asymmetric dimethylarginine in obesity after renal transplantation.

We have assessed in obese renal transplant recipients a course of selected proinflammatory factors liable to influence the long-term outcome of transplant patients and kidney grafts.



In a prospective cohort study, we examined a total of 68 obese renal transplant recipients (body mass index [BMI] >or= 30 kg/m(2)) for a period of 12 months (Group I). A control group consisted of 72 comparable non-obese renal transplant recipients (Group II).



Significant differences were found in plasma 12 months after renal transplantation (Group I versus Group II) in asymmetric dimethylarginine (ADMA; 3.68 micromol/L +/- 0.42 micromol/L vs 2.10 micromol/L +/- 0.34 micromol/L; P < .01), adiponectin (ADPN; 15.1 microg/mL +/- 6.0 microg/mL vs 22.80 microg/mL +/- 7.2 microg/mL; P < .01), leptin (50.4 ng/L +/- 10.2 ng/L vs 22.0 ng/L +/- 8.4 ng/L; P < .01), solubile leptin receptor (ObRe; 23.6 U/mL +/- 7.4 U/mL vs 47.2 U/mL +/- 10.7 U/mL; P < .01), resistin (21.2 microg/mL +/- 10.2 microg/mL vs 15.0 microg/mL +/- 6.2 microg/mL; P < .025) and triglycerides (3.9 mmol/L +/- 1.6 mmol/L vs 2.8 mmol/L +/- 1.6 mmol/L; P < .01). There were significant correlations between ADMA and BMI (r = 0.525, P < .001), ADPN and BMI (r = -0.574, P < .001), and ADMA and ADPN in visceral fat (r = -0.510, P < .001). Correlation between ADMA and Cin was weak, but significant (r = -0.190, P < .05).



The results indicate that obesity after renal transplantation was associated with increased plasma ADMA and decreased ADPN in plasma and in fat tissue and may represent a risk factor for renal transplant recipients.

Field of study: Medicine
PKI Trust Model Analysis Based on Probabilistic Model and Conditional Predicate Calculus Logic

A conditional predicate logic and probabilistic model are proposed for representing and reasoning about PKI trust model. Three predicates are defined to represent the relationships among the different entities, the reasoning rules about Authenticity, Trust extension, and Certification are given. A probabilistic model is given to measure the degree of confidence among these entities, this model can tell how these constraints affect on the confidence. Probabilistic model and conditional predicate can precisely express a PKI trust model.

Field of study: Computer science
The unbiasedness of hodges and lehman's test for a composite hypothesis of the man of a distribution with unknown variance

In 1954 Hodges and Lehmann considered the following problem: given is an i.i. normally distributed random sample with variance unknown. Under the null-hypothesis the mean is contained in a prescribed interval. Hodges and Lehmann constructed a test similar on the interval. This test is superior in power to the usual auxiliary procedure applied to this problem. Numerical calculations by Hodges and Lehmann indicated that the test is unbaised, however an analytical proof could not be given. In a recent paper the author proved unbiasedness for levels not too large, the magnitude depending on the sample size. Here the Proof is completed by establishing unbiasedness for all levels.

Field of study: Mathematics
Differentiation of bone marrow mesenchymal stem cells induced by myocardial medium under hypoxic conditions

To explore whether bone marrow mesenchymal stem cells (MSC) can differentiate into myocardial-like cells induced by myocardial medium, especially the hypoxia/reoxygenation-conditioned medium of cardiomyocytes.Myocardial cells obtained from neonatal Sprague-Dawley rat ventricles were isolated and cultured in vitro and a hypoxia reoxygenation model was established. The MSC isolated from adult Sprague-Dawley rats were purified and then incubated with 3 different mediums: medium A - the conditioned medium of normal cardiomyocytes; medium B - the conditioned medium of cardiomyocytes after hypoxia reoxygenation; and the control medium - ordinary medium. The expressions of the cardiac myosin heavy chain (MHC), troponin T (TnT) and connexin 43 were investigated in the MSC after 24 h, 48 h and 72 h cultivation, respectively.The MSC expressed MHC and TnT when incubated with the conditioned medium of cardiomyocytes after hypoxia reoxygenation, but did not express connexin 43. None of MHC, TnT and connexin 43 was detected in the MSC incubated with the conditioned medium of normal cardiomyocytes.The results indicate for the first time that myocardial medium for hypoxic preconditioning can induce MSC differentiation into myocardial-like cells.

Field of study: Biology, Chemistry, Medicine
Research on the Popularization and Application of New Energy Vehicles in China

The Chinese government attaches great importance to the development of new energy automotive industry driven by the pure electric vehicle. The subsidies, in recent years, has become an effective tool to promote the development of new energy automotive industry, and has played a positive role in promoting. This paper expounds the current situation of China's new energy automobile industry from two aspects: the current situation of new energy production in China and the new energy automobile technology route in China. And then, one suggestion that China should adopt the combination of tax and subsidy and adopts more diversified subsidy mode policies is put forward, by comparing the subsidy policy of new energy vehicles in China and abroad. Finally, this paper analyzes the declaration of 7 batch of new energy promotion catalogue by 2017, comparing the number and trend of each batch, the proportion of different types of new energy automobile products and the trend of quantity change, which reflects the development trend of new energy vehicles in China.

Field of study: Engineering
Achieving and Sustaining Institutional Excellence for the First Year of College

MAY/JUNE 2006 ◆ VOL 47 NO 3 363 graphic changes in higher education and discussed the high-tech culture among today’s student population. However, the authors failed to present a deeper analysis of diversity needs such as affordability, cultural perceptions and differences, and family support. The strong technology and administrative background of the authors may be the causes for this inadequacy. Readers may find more on this from another book, Technology Leadership: Communication and Information Systems in Higher Education by Maughan (2001), with a focus how a variety of needs can be accommodated, including those of students, faculty, and administrators. Overall, Higher Education in the Digital Age is a comprehensive book looking backwards into the development and impact of technology on university campuses, and a look forward to implications and possible impacts. As Brian J. Hawkins, President of EDUCAUSE put it, “This book—and especially the last four chapters—is a must read for any senior administrator in higher education today.”

Field of study: Education
Serum cytokine profile in patients with breast cancer

Highlights19 cytokine levels significantly differed between breast cancer patients and healthy controls.IL‐8, MIP‐1 alpha, MIP‐1 beta, MMP‐8, Resistin, FLRG, and BCAM were significantly higher in breast cancer patients, LAP and TSH‐&bgr; levels were lower.The above nine cytokines were clinically validated in breast cancer patients by ELISA.These nine cytokines represented up or down regulation in breast cancer.They may serve as novel biomarkers for diagnoses.  Breast cancer is the leading cause of cancer‐related death among women, with a more 20% 5‐year survival rate after metastases. It is therefore critical to improve early diagnosis in order to improve disease prognosis. This study investigates cytokine profiles of breast cancer serum with the aim of identifying biomarkers for early diagnosis. A solid‐phase antibody array was used for screening 274 biomarkers in serum from breast cancer patients. ELISA assay was carried out to identify biomarkers with differential expression. The serum levels of IL‐8, MIP‐1 alpha, MIP‐1 beta, MMP‐8, Resistin, FLRG, and BCAM were significantly higher in breast cancer patients, but LAP and TSH‐&bgr; levels were lower. ELISA assay results confirmed those of the antibody array. Our results suggest that these cytokines, screened by antibody array, might serve as novel inflammatory markers in breast cancer patients. Whether these biomarkers are specific for breast cancer and can help to improve diagnoses and prognoses of breast cancer needs further investigation.

Field of study: Medicine
Validation of a High-Order Large-Eddy Simulation Solver Using a Vertical-Axis Wind Turbine

A high-order implicit large-eddy simulation method in two dimensions and three dimensions is used to simulate the aerodynamics of a NACA0012 airfoil over large angles of attack at low chord Reynolds numbers (Re=5000–50,000). The two-dimensional code is found to have adequate agreement with lift and drag experimental data for prestall angles of attack, whereas the three-dimensional code is validated over all angles of attack. The three-dimensional method is able to accurately predict the magnitude and frequency content of the lift and drag forces on the airfoil throughout the range of Reynolds numbers considered in this study. Further comparisons to experimental data are made, including particle image velocimetry vorticity data as well as dye-injection data. As an extension of this application, a section of a constant spinning straight-bladed vertical-axis wind turbine with two blades at a similar Reynolds number is subject to various inflow velocities in two dimensions and three dimensions. The pitch angl...

Field of study: Physics
Research on Uniaxial Tension Test of Brain Tissue

Corresponding to low targeting accuracy due to tissue deformation during the process of electrode insertion in sub-thalamic nucleus deep brain stimulation (DBS), biomechanical properties of brain tissue are essential to investigate. In this paper the isolated porcine brain tissue is used in the uniaxial tensile test. Moreover, cylindrical samples of diameter (10 mm) and height (10 mm) are used to measure tensile length by single degree of axis at 5mm/s, until specimen was broken. The stretch ratio of brain tissue has been explored. The material failure criterion parameters, K, 1, 2, of MAT-QUASILINEAR-VISCOELASTIC biological material model in LS-DYNA are fitting calculated according to the experimental results. Six uniaxial failure data obtained from uniaxial tests are 4.81, 5.00, 4.07, 4.62, 4.28, 4.45 respectively. Three failure material constants 1, 2, K are -0.0084, -3.1944, -4.8095. The failure criterion is being implemented in LS-DYNA to simulate brain tissue.

Field of study: Engineering
One-stage combined delayed bladder closure with Kelly radical soft-tissue mobilization in bladder exstrophy: preliminary results.

The radical soft-tissue mobilization (RSTM, or Kelly repair) is an anatomical reconstruction of bladder exstrophy generally performed as a second part of a two-step strategy, following successful neonatal bladder closure.



The objective of this study is to determine the feasibility of a combined procedure of delayed bladder closure and RSTM in one stage without pelvic osteotomy, in both primary and failed initial closure.



From 11/2015 to 01/2018, 27 bladder exstrophy patients underwent combined bladder closure with RSTM by the same surgical team at four cooperating tertiary referral centers for bladder exstrophy, including 20 primary repairs (delayed bladder closure, median age 3.0m [0.5-37m]) and seven secondary repairs after failed attempt at neonatal closure, median age 10m [8-33m].



RSTM included full mobilization of the bladder plate, urogenital diaphragm, and corpora cavernosa from the medial pelvic walls, followed by anatomical reconstruction with antireflux procedure, bladder closure, urethrocervicoplasty, muscle sphincter approximation, and penile/clitoral reconstruction.



The main criteria were bladder dehiscence or prolapse. Secondary outcomes included bladder neck fistula or urethral fistula, urethral stenosis, and parietal hernia. Continence and voiding have not been addressed at this stage.



All bladder exstrophy cases were successfully closed without osteotomy, with no case of bladder dehiscence after 12 m [3-30] follow-up.



Urethral fistula or stenosis occurred in eight patients: 4/5 fistulae closed spontaneously in less than 3 months; four urethral stenoses were successfully treated with 1-3 sessions of endoscopic high-pressure balloon dilatation or meatoplasty; one patient with persistent bladder neck fistula is currently awaiting repair. Although the follow-up is short, it does allow examination of the main outcome criterion, namely bladder dehiscence, which is usually expected to happen very early after surgery.



The Kelly RSTM can be safely combined with delayed bladder closure without osteotomy in both primary and redo cases in classic bladder exstrophy.

Field of study: Medicine
Magmatic history of Red Sea rifting: perspective from the central Saudi Arabian coastal plain.

A newly recognized Tertiary dike complex and comagmatic volcanic rocks exposed on the central Saudi Arabian coastal plain record early stages of magmatism related to Red Sea rifting. Intrusive and stratigraphic relationships and new potassium-argon dating indicate episodic magmatism from about 30 Ma to the present. Additional stratigraphic and radiometric evidence suggests that limited rift-related magmatism began as early as about 50 Ma. An early phase of crustal extension in the region was accompanied by faulting and graben formation and by dike-swarm intrusion. The style of extension and intrusion changed at ∼20 Ma. Localized volcanism and sheeted dike injection ceased and were replaced by the intrusion of thick gabbro dikes. This change may mark the onset of sea-floor spreading in the central Red Sea. The dikes and volcanic rocks consist of a bimodal mafic-felsic suite with transitional subalkaline to alkaline chemistry. Although no unique petrogenetic model can be developed for the suite, the following observations and conclusions have been drawn from the available reconnaissance geochemistry: (1) strontium isotopic initial ratios overlap in the range 0.7031 to 0.7047 and are not clearly related to alkalinity or silica content. The bimodality and alkalinity of the suite are therefore not products of contamination by the radiogenic Precambrian upper-crustal granitic rocks exposed in the region. (2) Several of the evolved rocks (rhyolites and comendite) show large to extreme negative europium anomalies and heavy rare-earth–element (HREE) enrichment, features that cannot be explained by low-pressure crystal fractionation of potential parent magmas. An intriguing possibility is that HREE enrichments and large negative Eu anomalies of some peraluminous rhyolites (and granites) may result from the complete melting of garnet from middle or lower crustal rocks. (3) Most of the basalts are light rare-earth element (LREE) enriched, consistent with derivation from fertile mantle in a continental-rift setting; however, interaction of the mafic melts with lower continental crust cannot be ruled out. A model of poly-baric mantle-melt derivation, producing several alkaline-subalkaline cycles, best explains magmatism in the Red Sea region. Differences in the depths and dynamics of mantle-melt extraction and transport brought about through changes in crust and mantle structure as the rift and paar developed may account for the transition from mixed alkaline-subalkaline bimodal magmatism of the pre-20 Ma rift basin to exclusively subalkaline (tholeiitic) magmatism at the Red Sea spreading axis and to predominantly alkali basalt volcanism inland (within the Arabian Shield).

Field of study: Geology