Chirality of Matter Shows Up via Spin Excitations

Right- and left-handed circularly polarized light interact differently with electronic charges in chiral materials. This asymmetry generates the natural circular dichroism and gyrotropy, also known as the optical activity. Here we demonstrate that optical activity is not a privilege of the electronic charge excitations but it can also emerge for the spin excitations in magnetic matter. The square-lattice antiferromagnet Ba$_2$CoGe$_2$O$_7$ offers an ideal arena to test this idea, since it can be transformed to a chiral form by application of external magnetic fields. As a direct proof of the field-induced chiral state, we observed large optical activity when the light is in resonance with spin excitations at sub-terahertz frequencies. In addition, we found that the magnetochiral effect, the absorption difference for the light beams propagating parallel and anti-parallel to the applied magnetic field, has an exceptionally large amplitude close to 100%. All these features are ascribed to the magnetoelectric nature of spin excitations as they interact both with the electric and magnetic components of light

Evidence for similar structural brain anomalies in youth and adult attention-deficit/hyperactivity disorder: a machine learning analysis

Attention-deficit/hyperactivity disorder (ADHD) affects 5% of children world-wide. Of these, two-thirds continue to have impairing symptoms of ADHD into adulthood. Although a large literature implicates structural brain differences of the disorder, it is not clear if adults with ADHD have similar neuroanatomical differences as those seen in children with recent reports from the large ENIGMA-ADHD consortium finding structural differences for children but not for adults. This paper uses deep learning neural network classification models to determine if there are neuroanatomical changes in the brains of children with ADHD that are also observed for adult ADHD, and vice versa. We found that structural MRI data can significantly separate ADHD from control participants for both children and adults. Consistent with the prior reports from ENIGMA-ADHD, prediction performance and effect sizes were better for the child than the adult samples. The model trained on adult samples significantly predicted ADHD in the child sample, suggesting that our model learned anatomical features that are common to ADHD in childhood and adulthood. These results support the continuity of ADHD’s brain differences from childhood to adulthood. In addition, our work demonstrates a novel use of neural network classification models to test hypotheses about developmental continuity

Acute Confusional State in Elderly Patients with Hip Fracture. Identification of risk factors and intervention using a prehospital and perioperative management program

Abstract The overall aim of this thesis was to increase knowledge about underlying causes and perioperative risk factors of Acute Confusional State (ACS) in elderly patients with hip fracture and to investigate the effect of a multi-factorial intervention program in order to decrease the number of patients who develop ACS. The aim in paper I was to describe elderly patients with hip fracture on the basis of the American Society of Anesthesiologists’ ASA classification system and to identify preoperative risk factors in relation to the postoperative outcome measured up to 4-months after surgery. The aim in paper II was to identify perioperative risk factors in relation to postoperative outcome up to 4-months after surgery. In paper III the aim was to critically examine the Organic Brain Syndrome (OBS) Scale using the criteria and guidelines formulated by the Scientific Advisory Committee of the Medical Outcomes Trusts (SAC) for the evaluation of assessment instruments; and to investigate its relevance and suitability for use in various clinical settings. In paper IV the aim was to investigate whether an implementation of a multi-factorial intervention program including prehospital, pre-, intra- and postoperative treatment and care can reduce the incidence of acute ACS among elderly patients with hip fracture, lucid at admission to hospital. Design: In paper I and II a descriptive, cohort design was used, using data prospectively registered, and data retrospectively collected from medical records and nursing charts. The design used in study III was a two-stage strategy for identifying and reviewing scientific papers. In study IV a quasi-experimental, nonequivalent comparison group design was used. Results: In paper I risk factors for a poorer 4-month’s survival after hip fracture found were ‘ASA-status 3 and 4’, ‘more extensive fractures’, ‘age ≥85’, ‘male sex’, and ‘dependency in living.’ Mortality within 4-months was significantly associated with ‘ASA status 3 and 4’, ‘age ≥85 years’, ‘male sex’, ‘dementia diagnosis’, ‘Short Mental Status Questionnaire (SPMSQ) score <8 correct answers’, ‘prescribed drugs ≥4’, ‘hemoglobin <100 g/L’, ‘creatinine >100 micromol/L’, ‘dependency in living’, ‘unable to walk alone’, and ‘fracture other than undisplaced intracapsular’. In paper II significant perioperative risk factors for a poorer recovery and survival after hip fracture were ‘oxygen saturation (SpO2) <90 %’, ‘fasting time ≥12 hours’, and ‘blood transfusion ≥1 unit ’. ‘SpO2 <90 %’, and ‘blood transfusion ≥1’ unit were factors significantly associated with postoperative confusion, in-hospital complications and/or death within 4-months after hip fracture. A ‘postoperative hemoglobin <100 g/L’ was also significantly associated with postoperative confusion and in-hospital complications. In paper III the result showed that the OBS Scale in many aspects satisfies the requirements formulated by the SAC, but there is a need for additional evaluation, especially with regard to different forms of reliability, and the translation and adaptation to other languages. In paper IV the incidence of ACS was reduced by 64 % in the intervention group (29 of 131) compared to the control group (45 of 132) (p=0.031). Patients developing ACS had significantly higher levels of serious complications and 30-day mortality compared to patients without ACS. Conclusion: Elderly patients acutely admitted to hospital due to a hip fracture often suffer from increased morbidity. The incidence of complications is high in this patient group. It is of great importance that patients at risk of developing postoperative complications such as ACS are identified and treated promptly in order to prevent complications. Patient’s baseline characteristics, such as high age, number of prescribed drugs, or functional status are not possible to affect. On the other hand, factors such as oxygen saturation in blood, anemia, fluid balance, pain, or the length of fasting time are possible to intervene already at an early stage

Practical algorithm to inform clinical decision‐making in the topical treatment of atopic dermatitis

Atopic dermatitis is a chronic relapsing, inflammatory skin disorder associated with skin barrier dysfunction, the prevalence of which has increased dramatically in developing countries. In this article, we propose a treatment algorithm for patients with mild-tomoderate and severe atopic dermatitis flares in daily clinical practice. An international panel of 15 dermatology and allergy experts from eight countries was formed to develop a practical algorithm for the treatment of patients with atopic dermatitis, with a particular focus on topical therapies. In cases of mild-to-moderate atopic dermatitis involving sensitive skin areas, the topical calcineurin inhibitor pimecrolimus should be applied twice daily at the first signs of atopic dermatitis. For other body locations, patients should apply a topical calcineurin inhibitor, either pimecrolimus or tacrolimus, twice daily at the first signs of atopic dermatitis, such as pruritus, or twice weekly in previously affected skin areas. Emollients should be used regularly. Patients experiencing acute atopic dermatitis flares in sensitive skin areas should apply a topical corticosteroid twice daily or alternate once-daily topical corticosteroid/topical calcineurin inhibitor until symptoms improve. Following improvement, topical corticosteroid therapy should be discontinued and patients switched to a topical calcineurin inhibitor. Maintenance therapy should include the use of pimecrolimus once daily for sensitive areas and tacrolimus for other body locations. This treatment algorithm can help guide clinical decision-making in the treatment of atopic dermatitis