Theory and modeling of molecular modes in the NMR relaxation of fluids

Traditional theories of the NMR autocorrelation function for intramolecular dipole pairs assume single-exponential decay, yet the calculated autocorrelation of realistic systems display a rich, multi-exponential behavior resulting in anomalous NMR relaxation dispersion (i.e., frequency dependence). We develop an approach to model and interpret the multi-exponential autocorrelation using simple, physical models within a rigorous statistical mechanical development that encompasses both rotational and translational diffusion in the same framework. We recast the problem of evaluating the autocorrelation in terms of averaging over a diffusion propagator whose evolution is described by a Fokker-Planck equation. The time-independent part admits an eigenfunction expansion, allowing us to write the propagator as a sum over modes. Each mode has a spatial part that depends on the specified eigenfunction, and a temporal part that depends on the corresponding eigenvalue (i.e., correlation time) with a simple, exponential decay. The spatial part is a probability distribution of the dipole-pair, analogous to the stationary states of a quantum harmonic oscillator. Drawing inspiration from the idea of inherent structures in liquids, we interpret each of the spatial contributions as a specific molecular mode. These modes can be used to model and predict NMR dipole-dipole relaxation dispersion of fluids by incorporating phenomena on the molecular level. We validate our statistical mechanical description of the distribution in molecular modes with molecular dynamics simulations interpreted without any relaxation models or adjustable parameters: the most important poles in the Pad{\'e}-Laplace transform of the simulated autocorrelation agree with the eigenvalues predicted by the theory

Attachment, infidelity, and loneliness in college students involved in a romantic relationship: the role of relationship satisfaction, morbidity and prayer for partner

This study examined the mediating effects of relationship satisfaction, prayer for a partner, and morbidity in the relationship between attachment and loneliness, infidelity and loneliness, and psychological morbidity and loneliness, in college students involved in a romantic relationship. Participants were students in an introductory course on family development. This study examined only students (n = 345) who were involved in a romantic relationship. The average age of participants was 19.46 (SD = 1.92) and 25 % were males. Short-form UCLA Loneliness Scale (ULS-8), (Hays and DiMatteo in J Pers Assess 51:69–81, doi:10.1207/s15327752jpa5101_6, 1987); Relationship Satisfaction Scale (Funk and Rogge in J Fam Psychol 21:572–583, doi:10.1037/0893-3200.21.4.572, 2007); Rotterdam Symptom Checklist (De Haes et al. in Measuring the quality of life of cancer patients with the Rotterdam Symptom Checklist (RSCL): a manual, Northern Centre for Healthcare Research, Groningen, 1996); Prayer for Partner Scale, (Fincham et al. in J Pers Soc Psychol 99:649–659, doi:10.1037/a0019628, 2010); Infidelity Scale, (Drigotas et al. in J Pers Soc Psychol 77:509–524, doi:10.1037/0022-3514.77.3.509, 1999); and the Experiences in Close Relationship Scale-short form (Wei et al. in J Couns Psychol 52(4):602–614, doi:10.1037/0022-0167.52.4.602, 2005). Results showed that relationship satisfaction mediated the relationship between avoidance attachment and loneliness and between infidelity and loneliness. Physical morbidity mediated the relationship between anxious attachment and psychological morbidity. Psychological morbidity mediated the relationship between anxious attachment and physical morbidity. The present results expand the literature on attachment by presenting evidence that anxious and avoidant partners experience loneliness differently. Implications for couple’s therapy are addressed. Future research should replicate these results with older samples and married couples.Acknowledgments This research was supported by Grant Number 90FE0022 from the United States Department of Health and Human Services awarded to the last author

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Influence of the temperature dependence of the yield stress on the stress distribution in a heat-generating tube with free ends

Based on Tresca's yield condition and its associated flow rule, the elastic-plastic deformation of a heat-generating tube with free ends is investigated by taking into consideration the influence of the temperature dependence of the yield stress. It is found that the expansion of the inner plastic zones as well as the stress state are affected markedly owing to the reduction in the yield stress at elevated temperatures, The stress distribution and the expansion of different plastic regions are displayed graphically and discussed

Elastic-plastic deformation of a heat generating tube with temperature-dependent yield stress

The distribution of stress, plastic strain and displacement in an elastic-perfectly plastic tube with fixed ends in the presence of a uniform heat source is investigated analytically by taking into consideration the temperature dependence of the yield limit. The treatment is based on Tresca's yield condition and its associated flow rule. Depending on the radius ratio of the tube, in general, five different plastic regions, two of them corresponding to an edge regime of Tresca's prism, and an intermediate elastic region occur. Four different ranges of radius ratio of the tube can be distinguished which lead to different patterns of elastic-plastic deformation. In all cases the thermal load is increased up to the value for which the elastic region vanishes

On the elastic-plastic deformation of a centrally heated cylinder exhibiting linear hardening

A closed-form solution of the elastic-plastic deformation of a cylinder with uniform temperature inside its cylindrical core and zero surface temperature is presented for a linearly strain hardening material. The analysis is based on Tresca's yield condition and its associated flow rule. The effect of hardening on the expansion of plastic regions and on the distribution of stress is displayed graphically

Determinants of Human Capital Theory, Growth and Brain Drain: An Econometric Analysis for 77 Countries

The study aims to analyse the relation between human capital, growth and brain drain in 77 countries. These variables are also affected by numerous other variables. This study researches human capital, growth, migration, their determinant variables and the interlink ages between them. Models constructed for these purposes are tested by panel data analysis for the period 1990 – 2001.Human Capital, Growth, International Migration, Panel Data Analysis

Myocilin Mt1 Promoter Polymorphism In Turkish Patients With Primary Open Angle Glaucoma

Purpose: To evaluate the association of the myocilin gene promoter variant -1000C>G (MYOC.mt1) with primary open angle glaucoma (POAG) and its possible role on the phenotype and the severity of glaucoma in Turkish patients. Methods: Eighty eight POAG patients and 123 healthy subjects were included in the study. All subjects were genotyped by PCR-RFLP. Allele and genotype frequencies between healthy subjects and glaucoma patients were compared by the chi(2) test. The age at diagnosis, the age at inclusion, the maximum IOP at diagnosis and the number of antiglaucomatous medications were compared between MYOC.mt1 carriers and non-carriers using the Student's t-test; C/D ratio, mean deviation (MD), and pattern standard deviation values were compared with the Mann-Whitney U-test. Statistical significance was defined as p0.05). No significant difference was found in the distribution of genotypes between different stages of glaucoma groups (p=0.93). Conclusions: Our results suggest that in our Turkish glaucoma patients, MYOC.mt1 is not a risk factor for the development of POAG and is not associated with the phenotype and severity of glaucoma.Wo