Scattering theory and ground-state energy of Dirac fermions in graphene with two Coulomb impurities

We study the physics of Dirac fermions in a gapped graphene monolayer containing two Coulomb impurities. For the case of equal impurity charges, we discuss the ground-state energy using the linear combination of atomic orbitals (LCAO) approach. For opposite charges of the Coulomb centers, an electric dipole potential results at large distances. We provide a nonperturbative analysis of the corresponding low-energy scattering problem

Fourteen days of smoking cessation improves muscle fatigue resistance and reverses markers of systemic inflammation

Cigarette smoking has a negative effect on respiratory and skeletal muscle function and is a risk factor for various chronic diseases. To assess the effects of 14 days of smoking cessation on respiratory and skeletal muscle function, markers of inflammation and oxidative stress in humans. Spirometry, skeletal muscle function, circulating carboxyhaemoglobin levels, advanced glycation end products (AGEs), markers of oxidative stress and serum cytokines were measured in 38 non-smokers, and in 48 cigarette smokers at baseline and after 14 days of smoking cessation. Peak expiratory flow (p = 0.004) and forced expiratory volume in 1 s/forced vital capacity (p = 0.037) were lower in smokers compared to non-smokers but did not change significantly after smoking cessation. Smoking cessation increased skeletal muscle fatigue resistance (p < 0.001). Haemoglobin content, haematocrit, carboxyhaemoglobin, total AGEs, malondialdehyde, TNF-α, IL-2, IL-4, IL-6 and IL-10 (p < 0.05) levels were higher, and total antioxidant status (TAS), IL-12p70 and eosinophil numbers were lower (p < 0.05) in smokers. IL-4, IL-6, IL-10 and IL-12p70 had returned towards levels seen in non-smokers after 14 days smoking cessation (p < 0.05), and IL-2 and TNF-α showed a similar pattern but had not yet fully returned to levels seen in non-smokers. Haemoglobin, haematocrit, eosinophil count, AGEs, MDA and TAS did not significantly change with smoking cessation. Two weeks of smoking cessation was accompanied with an improved muscle fatigue resistance and a reduction in low-grade systemic inflammation in smokers

Primary insomnia: New aspects of diagnosis and differential diagnosis, aetiology and pathophysiology and psychotherapy

This review article focusses on the state of the art of research and clinical work with respect to primary insomnia. The ICSD-2 is a new diagnostic classification system encompassing a separate chapter on insomnias. Furthermore, the research diagnostic criteria (RDC) for insomnia, having been recently published, will be of relevance for future research in the field of insomnia. The focus of etiological and pathophysiological theories is the hyperarousal concept. This concept is based on the assumption that patients with chronic primary insomnia display a psychophysiological arousal, manifested for example in increased cortisol secretion or enhanced fast frequencies in the sleep EEG. On a molecular genetic level alterations in the adenosine system could be at the core of the hyperarousal. New psychological concepts of primary insomnia focus on attention processes which might play a role for the chronic course of insomnias. Also in detail discussed will be psychotherapeutic concepts, especially cognitive behavioural strategies for the treatment of primary insomnia. These concepts have been subjected to rigorous evidence based testing and can claim a high degree of scientific evidence. © 2007 Steinkopff-Verlag

Primary insomnia: New aspects of diagnosis and differential diagnosis, aetiology and pathophysiology and psychotherapy. [German]

This review article focusses on the state of the art of research and clinical work with respect to primary insomnia. The ICSD-2 is a new diagnostic classification system encompassing a separate chapter on insomnias. Furthermore, the research diagnostic criteria (RDC) for insomnia, having been recently published, will be of relevance for future research in the field of insomnia. The focus of etiological and pathophysiological theories is the hyperarousal concept. This concept is based on the assumption that patients with chronic primary insomnia display a psychophysiological arousal, manifested for example in increased cortisol secretion or enhanced fast frequencies in the sleep EEG. On a molecular genetic level alterations in the adenosine system could be at the core of the hyperarousal. New psychological concepts of primary insomnia focus on attention processes which might play a role for the chronic course of insomnias. Also in detail discussed will be psychotherapeutic concepts, especially cognitive behavioural strategies for the treatment of primary insomnia. These concepts have been subjected to rigorous evidence based testing and can claim a high degree of scientific evidence. © 2007 Steinkopff-Verlag