Symmetry of the Atomic Electron Density in Hartree, Hartree-Fock, and Density Functional Theory

The density of an atom in a state of well-defined angular momentum has a specific finite spherical harmonic content, without and with interactions. Approximate single-particle schemes, such as the Hartree, Hartree-Fock, and Local Density Approximations, generally violate this feature. We analyze, by means of perturbation theory, the degree of this violation and show that it is small. The correct symmetry of the density can be assured by a constrained-search formulation without significantly altering the calculated energies. We compare our procedure to the (different) common practice of spherically averaging the self-consistent potential. Kohn-Sham density functional theory with the exact exchange-correlation potential has the correct finite spherical harmonic content in its density; but the corresponding exact single particle potential and wavefunctions contain an infinite number of spherical harmonics.Comment: 11 pages, 6 figures. Expanded discussion of spherical harmonic expansion of Hartree density. Some typos corrected, references adde

Can routine register data be used to identify vulnerable lung cancer patients of suboptimal care in a German comprehensive cancer centre?

Objectives Several patient factors have been described to influence access to optimal cancer care like socioeconomic factors or place of residence. In this study, we investigate whether data routinely collected in a clinical cancer registry can be used to identify populations of lung cancer patients with increased risk of not receiving optimal cancer care.Methods We analysed data of 837 lung cancer patients extracted from the clinical cancer registry of a German university hospital. We compared patient populations by two indicators of optimal care, namely implementation of tumour board meeting recommendations as well as the timeliness of care.Results There was a high rate of implementation of tumour board meeting recommendations of 94.4%. Reasons for non-implementation were mainly a patient's own wish or a worsening of the health situation. Of all patient parameters, only tumour stage was associated with the two optimal care indicators.Conclusion Using routine data from a clinical cancer registry, we were not able to identify patient populations at risk of not getting optimal care and the implementation of guideline-conform care appeared to be very high in this setting. However, limitations were the ambiguity of optimal care indicators and availability of parameters predictive for patients' vulnerability.Clinical epidemiolog

The impact of short-term psycho-oncological interventions on the psychological outcome of cancer patients of a surgical-oncology department - A randomised controlled study

BACKGROUND: Anxiety and depression are the two most frequent comorbidities of tumour patients. At present, it is unclear to which degree a patient's psychological condition can be altered during the treatment period and if psycho-oncological support positively affects a patient's psychological condition. METHODS: In a random sample analyses, 131 patients beginning inpatient treatment at a hospital specialising in surgical oncology were either classified as 'low-risk' or 'high-risk', according to the HADS. Patients from both categories were then randomly placed in either a low-threshold 'intervention' group or an 'observation' group. Anxiety and depression levels were measured again with the HADS scale prior to the patients discharge from the department of surgical oncology, and at a follow up 12months after. RESULTS: Our findings showed a significant reduction of anxiety and depression in the high-risk patients who had undergone psycho-oncological intervention at the end of inpatient care and even a year after discharge from the hospital. The effects of psychological intervention could be observed in terms of anxiety and depression in the group of high-risk patients during the hospital stay. In the other three groups, no statistically significant changes could be measured. CONCLUSION: Cancer patients on a surgical ward benefit from psycho-oncological support especially at an early stage of therapy but also over a long time after discharge from the hospital. The aim of all interventions should be to decrease psychological distress and disorders and thereby improve the quality of life for cancer patients