X-ray 3D imaging-based microunderstanding of granular mixtures: Stiffness enhancement by adding small fractions of soft particles.

This research focuses on performing ultrasound propagation measurements and micro-X-ray computed tomography (µXRCT) imaging on prestressed granular packings prepared with biphasic mixtures of monodisperse glass and rubber particles at different compositions/fractions. Ultrasound experiments employing piezoelectric transducers, mounted in an oedometric cell (complementing earlier triaxial cell experiments), are used to excite and detect longitudinal ultrasound waves through randomly prepared mixtures of monodisperse stiff/soft particles. While the fraction of the soft particles is increasing linearly from zero, the effective macroscopic stiffness of the granular packings transits nonlinearly and nonmonotonically toward the soft limit, remarkably via an interesting stiffer regime for small rubber fractions between 0.1 ≲ ν ≲ 0.2. The contact network of dense packings, as accessed from µXRCT, plays a key role in understanding this phenomenon, considering the structure of the network, the chain length, the grain contacts, and the particle coordination. While the maximum stiffness is due to surprisingly shortened chains, the sudden drop in elastic stiffness of the mixture packings, at ν ≈ 0.4, is associated with chains of particles that include both glass and rubber particles (soft chains); for ν ≲ 0.3, the dominant chains include only glass particles (hard chains). At the drop, ν ≈ 0.4, the coordination number of glass and rubber networks is approximately four and three, respectively, i.e., neither of the networks are jammed, and the chains need to include particles from another species to propagate information.

[Neuromuscular scoliosis in patients with central nervous system pathologies]. / Neuromuskuläre Skoliose bei Erkrankungen des zentralen Nervensystems.

Neuromuscular scoliosis is due to pathologies within the neuromuscular pathway. These pathologies result in early deformities, usually with ongoing rapid progress. Conservative treatment has only limited value in these individuals, and posterior instrumented surgical correction to the spine is the favored treatment concept for correction and avoidance of progression. Here, we illuminate the special treatment concepts for children with NMS due to pathologies of the central nervous system also with a closer look at new treatment modalities. Moreover, we describe two typical cases in detail.

[Deep lumbar back pain and neurological sensory deficits in a 56-year-old male patient]. / Tief lumbaler Rückenschmerz und sensible neurologische Ausfälle bei einem 56-jährigen Patienten.

Echinococcus infestations are rare in humans, infestation of bone occurs in less than 1% and a primary spinal infestation is extremely rare. This article reports on a clinical case of lumbar and sacral spinal infestation by Echinococcus multilocularis in a 56-year-old male Caucasian with neurological sensory deficits and deep lumbar back pain. Due to the suspicion of spondylodiscitis a computer tomography-guided biopsy was carried out without success, so that a sample was surgically obtained. The diagnosis of a spinal Echinococcus infestation could be made. A radical surgical débridement was carried out and anthelminthic treatment was started. This article describes this unusual case in detail and gives a brief summary of the current literature on this disease.

Two-Loop Four-Graviton Scattering Amplitudes.

We present the analytic form of the two-loop four-graviton scattering amplitudes in Einstein gravity. To remove ultraviolet divergences we include counterterms quadratic and cubic in the Riemann curvature tensor. The two-loop numerical unitarity approach is used to deal with the challenging momentum dependence of the interactions. We exploit the algebraic properties of the integrand of the amplitude in order to reduce it to a minimal basis of Feynman integrals. Analytic expressions are obtained from numerical evaluations of the amplitude. Finally, we show that four-graviton scattering observables depend on fewer couplings than naïvely expected.

[Harlequin syndrome after scoliosis surgery]. / Harlekinsyndrom nach Skoliosechirurgie.

Harlequin syndrome is a rare combination of symptoms, characterized by unilateral facial anhidrosis and paleness on the affected side, becoming obvious by contralateral flushing mainly during sports activity. The syndrome is mostly idiopathic, however it is also described as a complication of thoracic surgery, i.e. superior lobectomy. Here, we report on two cases of Harlequin syndrome following scoliosis surgery at the cervicothoracic junction.

[Degenerative cervical spine diseases: fusion vs. total disc replacement : What can be done when?] / Degenerative Halswirbelsäulenerkrankungen: Fusion vs. bewegungserhaltende Verfahren : Wann ist was sinnvoll?

Motion preserving surgery within the cervical spine may be performed by special implants, for example, c spine disc prosthesis or total disc replacement (cTDR), or by simple decompression of the cervical nerve roots. However, also fusion surgery may be performed with good results. Here, we summarize indications as well as contraindications for motion preserving techniques and indications for fusion surgery. cTDR is indicated in special cases of soft disc herniation, especially in younger individuals without signs of myelopathy. Posterior decompression may be used as an alternative, especially if anterior surgery is not possible. If degeneration is severe, in the presence of kyphosis, severe canal encroachment, instability, and in cases of myelopathy, cervical spine fusion seems to be the better way.

High prevalence of hepatitis C (HCV) in the emergency department (ED) of a London hospital: should we be screening for HCV in ED attendees?

An unlinked anonymous study was conducted to estimate the prevalence of hepatitis C virus (HCV) infection in emergency department (ED) attendees at a London Hospital. Nine hundred and ninety-seven samples collected over a 12-day period were tested for HCV antibody (Ab) and reactive samples were further tested for HCV RNA. The HCV seroprevalence was 2·6% (26/997) with 1·2% (12/997) HCV RNA positive. A peak HCV RNA-positive prevalence of 4·8% (3/63) was found in males aged 35-44 years, this was compared to 0% (0/136) in males aged <35 years (P = 0·0614) and 1·4% (4/278) in males aged ⩾45 years (P = 0·2415). Assuming the cost for HCV Ab is £6 and HCV RNA is £40 per test, screening ED attendees aged 25-54 years would cost £360 per viraemic infection and identify 82% of those who were HCV RNA positive, yielding the most favourable cost/benefit ratio. HCV screening of ED attendees aged 25-54 years in this population could be an effective way of identifying patients and limit onward transmission.

Ribosomal protein S6 is hyperactivated and differentially phosphorylated in epidermal lesions of patients with psoriasis and atopic dermatitis.

BACKGROUND: The ribosomal protein S6 is part of the translation machinery and is activated by phosphorylation via the mammalian target of rapamycin pathway, which is activated in psoriatic skin. OBJECTIVES: To investigate which S6 sites are phosphorylated in psoriasis and atopic dermatitis (AD), and to study whether S6 phosphorylation is associated with inflammation and/or keratinocyte hyperproliferation. METHODS: Healthy skin and skin lesions of patients with psoriasis and AD were investigated by immunostaining using antibodies that stain proliferating cells, leucocytes and distinct phosphorylated sites of S6. RESULTS: All psoriasis and AD lesions revealed abnormal S6 phosphorylation in the epidermis. The extent of S6 phosphorylation was diverse, generally stronger in psoriasis and correlated, in both diseases, with inflammation. S6 showed differential phosphorylation in distinct epidermal layers, which was most pronounced in hyperproliferative regions. CONCLUSIONS: Differential S6 phosphorylation may have a role in abnormal keratinocyte proliferation/differentiation.

Diagnosing HIV infection in patients presenting with glandular fever-like illness in primary care: are we missing primary HIV infection?

OBJECTIVES: The aim of the study was to examine the prevalence of HIV infection in patients presenting in primary care with glandular fever (GF)-like illness. METHODS: Samples from primary care submitted for a GF screen between April 2009 and June 2010 were identified. Samples without an HIV request were anonymized and retrospectively tested using a 4th-generation HIV antigen/antibody screening test. Reactive samples were further confirmed by an HIV antibody only test, with or without a p24 antigen assay. Antibody avidity testing based on the Recent HIV Infection Testing Algorithm (RITA) was used to identify individuals with evidence of recent acquisition (within 4-5 months). RESULTS: Of 1046 GF screening requests, concomitant HIV requests were made in 119 patients. Excluding one known positive patient, 2.5% (three of 118) tested HIV positive. Forty-five (4.3%) had a subsequent HIV test through another consultation within 1 year; of these, 4.4% (two of 45) tested positive. Of the remaining 882 patients, 694 (78.7%) had samples available for unlinked anonymous HIV testing, of which six (0.9%) tested positive. The overall HIV prevalence was 1.3% (11 of 857), with 72.7% (eight of 11) of cases missed at initial primary care presentation. Four of the nine (44.4%) available positive samples had evidence of recent acquisition, with three (75.0%) missed at initial primary care presentation. CONCLUSION: Low levels of HIV testing in patients presenting in primary care with GF-like illness are resulting in a significant number of missed HIV and seroconversion diagnoses. Local policy should consider adopting an opt-out strategy to include HIV testing routinely within the GF-screening investigation panel.

Treatment of traumatized victims of war and torture: a randomized controlled comparison of narrative exposure therapy and stress inoculation training.

BACKGROUND: The aim of the present randomized controlled trial was to compare the outcome of 2 active treatments for posttraumatic stress disorder (PTSD) as a consequence of war and torture: narrative exposure therapy (NET) and stress inoculation training (SIT). METHODS: Twenty-eight PTSD patients who had experienced war and torture, most of them asylum seekers, received 10 treatment sessions of either NET or SIT at the Outpatient Clinic for Refugees, University of Konstanz, Germany. Posttests were carried out 4 weeks after treatment, and follow-up tests were performed 6 months and 1 year after treatment. The main outcome measure was the PTSD severity score according to the Clinician-Administered PTSD Scale (CAPS) at each time point. RESULTS: A significant reduction in PTSD severity was found for NET, but not for SIT. A symptom reduction in the NET group occurred between pretest and the 6-month follow-up examination, the effect size being d = 1.42 (for SIT: d = 0.12), and between pretest and the 1-year follow-up, the effect size being d = 1.59 (for SIT: d = 0.19). The rates and scores of major depression and other comorbid disorders did not decrease significantly over time in either of the 2 treatment groups. CONCLUSIONS: The results indicate that exposure treatments like NET lead to a significant PTSD symptom reduction even in severely traumatized refugees and asylum seekers.

On the relation between the activation energy for electron attachment reactions and the size of their thermal rate coefficients.

Rate coefficients k(T) for dissociative electron attachment (DEA) to molecules in many cases exhibit a more or less strong rise with increasing temperature T (the electron temperature T(e) and the molecular temperature T(G) are assumed to be in thermal equilibrium, i.e., T = T(e) = T(G)). This rise is frequently modeled by the Arrhenius equation k(T) = k(A) exp[-E(a)∕(k(B)T)], and an activation energy E(a) is deduced from fits to the experimental data k(T). This behavior reflects the presence of an energy barrier for the anion on its path to the dissociated products. In a recent paper [J. Kopyra, J. Wnorowska, M. Forys, and I. Szamrej, Int. J. Mass Spectrom. 268, 60 (2007)] it was suggested that the size of the rate coefficients for DEA reactions at room temperature exhibits an exponential dependence on the activation energy, i.e., k(E(a); T ≈ 300 K) = k(1) exp[-E(a)∕E(0)]. More recent experimental data for molecules with high barriers [T. M. Miller, J. F. Friedman, L. C. Schaffer, and A. A. Viggiano, J. Chem. Phys. 131, 084302 (2009)] are compatible with such a correlation. We investigate the validity and the possible origin of this dependence by analyzing the results of R-matrix calculations for temperature-dependent rate coefficients of exothermic DEA processes with intermediate barrier toward dissociation. These include results for model systems with systematically varied barrier height as well as results of molecule-specific calculations for CH(3)Cl, CH(3)Br, CF(3)Cl, and CH(2)Cl(2) (activation energies above 0.2 eV) involving appropriate molecular parameters. A comparison of the experimental and theoretical results for the considered class of molecules (halogenated alkanes) supports the idea that the exponential dependence of k(T = 300 K) on the activation energy reflects a general phenomenon associated with Franck-Condon factors for getting from the initial neutral vibrational levels to the dissociating final anion state in a direct DEA process. Cases are discussed for which the proposed relation does not apply.

Script-driven imagery of self-injurious behavior in patients with borderline personality disorder: a pilot FMRI study.

OBJECTIVE: Self-injurious behavior (SIB) is one of the most distinctive features of borderline personality disorder (BPD) and related to impulsivity and emotional dysregulation. METHOD: Female patients with BPD (n = 11) and healthy controls (n = 10) underwent functional magnetic resonance imaging while listening to a standardized script describing an act of self-injury. Experimental sections of the script were contrasted to the neutral baseline section and group-specific brain activities were compared. RESULTS: While imagining the reactions to a situation triggering SIB, patients with BPD showed significantly less activation in the orbitofrontal cortex compared with controls. Furthermore, only patients with BPD showed increased activity in the dorsolateral prefrontal cortex during this section and a decrease in the mid-cingulate while imagining the self-injurious act itself. CONCLUSION: This pattern of activation preliminary suggests an association with diminished emotion regulation, impulse control as well as with response selection and reappraisal during the imagination of SIB.

Low-energy electron attachment to the dichlorodifluoromethane (CCl2F2) molecule.

Results from a joint experimental study of electron attachment to dichlorodifluoromethane (CCl(2)F(2)) molecules in the gas phase are reported. In a high resolution electron beam experiment involving two versions of the laser photoelectron attachment method, the relative cross section for formation of the dominant anion Cl(-) was measured over the energy range 0.001-1.8 eV at the gas temperature T(G) = 300 K. It exhibits cusp structure at thresholds for vibrational excitation of the nu(3)(a(1)) mode due to interaction with the attachment channels. With reference to the thermal attachment rate coefficient k(T = 300 K) = 2.2(8) x 10(-9) cm(3) s(-1) (fitted average from several data), a new highly resolved absolute attachment cross section for T(G) = 300 K was determined. Partial cross sections for formation of the anions Cl(-), Cl(2)(-), F(-), ClF(-), and CCl(2)F(-) were measured over the range 0-12 eV, using three different electron beam experiments of medium energy resolution. The dependence of the attachment rate coefficient k(T(e);T(G) = 300 K) on electron temperature T(e) was calculated over the range 50-15 000 K, based on a newly constructed total cross section for anion formation at T(G) = 300 K. R-matrix calculations for Cl(-) production have been carried out for comparison with the experimental data. The R-matrix results are in line with the main experimental observations and predict the dependence of the DEA cross section on the initial vibrational level nu(3)() and on the vibrational temperature. Furthermore, the cross section for vibrational excitation of the nu(3) mode has been computed.

Increase in diagnosed newly acquired hepatitis C in HIV-positive men who have sex with men across London and Brighton, 2002-2006: is this an outbreak?

OBJECTIVES: To determine the incidence of diagnosed newly acquired hepatitis C virus (HCV) in HIV-positive men who have sex with men (MSM) across London and Brighton in order to inform public health interventions. METHODS: Cases were defined as MSM attending London and Brighton HIV/genitourinary medicine clinics from January 2002 to June 2006, with HCV PCR RNA or antibody positive, and a negative HCV test in the previous three years. The yearly number of cases and HCV screening policy in MSM were examined. A negative binomial regression model was used to estimate HCV incidence density rate ratio and 95% CI. RESULTS: 20 out of 38 clinics provided information, covering 84% of the HIV-positive MSM workload in London and 100% in Brighton. The estimated overall incidence was 9.05 per 1000 HIV-positive MSM patient-years. It increased from 6.86 per 1000 in 2002 to 11.58 per 1000 during January-June 2006. Incidence at clinics ranged from 0 to 15.4 (median 6.52) per 1000 HIV-positive MSM patient-years. There was some evidence of difference in the incidence and trend (p = 0.02) in each clinic. The average annual rise in incidence of HCV was 20% (95% CI 4% to 39%, p = 0.001). There was little evidence of such transmission among MSM with negative or unknown HIV status. CONCLUSIONS: HCV incidence clearly increased among HIV-positive MSM in London and Brighton during January 2002 to June 2006. Prospective enhanced surveillance of HCV in MSM, including HIV status and behavioural risk factors, is recommended to help inform control measures and better determine the frequency of transmission in all MSM.

Setting up an enhanced surveillance of newly acquired hepatitis C infection in men who have sex with men: a pilot in London and South East region of England.

Preliminary findings suggest ongoing HCV transmission among MSM infected with human immunodeficiency virus (HIV) and that enhanced surveillance for newly acquired HCV in MSM is feasible.

The influence of micronutrients on cognitive function and performance.

There has been much media speculation (often sensationalist and conflicting) regarding the potential influence of micronutrients on cognitive function and performance. Our aim was to identify the micronutrients specifically implicated in cognitive function and to review the literature to identify original sources underlying the media coverage. Literature searches were carried out to identify recent clinical trials, reviews, editorials and meetings describing the biochemical and physiological role of individual micronutrients. No attempt was made to grade the evidence. The searches confirmed that the water-soluble vitamins (B group and C), together with the minerals, calcium, magnesium and zinc, are most relevant to cognitive performance. Clinical evidence revealed that marginal deficiencies of one or more of these micronutrients are not uncommon, even in the developed countries, and that such deficiencies may affect cognitive performance, especially in vulnerable groups such as the elderly and those individuals who are exposed to occupational pressures and a stressful lifestyle.

The role of vitamins and minerals in energy metabolism and well-being.

Physicians are frequently confronted with patients complaining of fatigue, tiredness and low energy levels. In the absence of underlying disease, these symptoms could be caused by a lack of vitamins and minerals. Certain risk groups like the elderly and pregnant women are well-recognized. Our aim was, therefore, to find out if other, less well-established groups might also be at risk. Thus, the objectives of this review are: to describe the inter-relationship between micronutrients, energy metabolism and well-being; identify risk groups for inadequate micronutrient intake; and explore the role of micronutrient supplementation in these groups. A review of the literature identified an important group at risk of inadequate micronutrient intake: young adults, often women, with a demanding lifestyle who are physically active and whose dietary behaviour is characterized by poor choices and/or regular dieting. Micronutrient supplementation can alleviate deficiencies, but supplements must be taken for an adequate period of time.