Reducing crosstalk in optically-pumped magnetometer arrays.

Optically pumped magnetometers (OPMs) operating in the spin-exchange relaxation-free regime are emerging as alternative sensors to superconducting quantum interference devices (SQUIDs) for magnetoencephalography (MEG). As the number of OPMs in a single imaging system increases to rival SQUID MEG systems, cross-talk between nearby sensors limits the measurement accuracy. We experimentally demonstrate a coil geometry, which generates an order of magnitude less cross-talk (less than 0.5%) than a Helmholtz coil (8%). The new coil design is simple and compact, requiring two coaxial coil pairs that add 1 mm to the 6 mm radius and is driven by a single current driver. The new design maintains a magnetic field homogeneity over the volume of the magnetometer of more than 94%, which is sufficient for the zero-field OPM to operate in a 200 nT ambient field environment. Our result increases the feasibility of high-spatial resolution OPM-based bio-magnetic imaging technology due to the reduction of cross-talk at high sensor density.

Characterization of noise sources in a microfabricated single-beam zero-field optically-pumped magnetometer.

We present an experimental noise characterization of a miniature single-beam absorption-based optically-pumped magnetometer with a noise floor of 7 fT/Hz1/2 operating in the spin-exchange relaxation-free regime. We experimentally evaluate noise arising from the laser intensity, laser frequency, laser polarization, cell temperature, and magnetic field coils used for the phase-sensitive detection of the magnetometer signal. We find that noise in the range between DC and 30 Hz is a result of noise sources coupling to the atoms in a manner similar to a magnetic field, while the noise at frequencies above 30 Hz is mainly due to laser intensity noise. Our results place an upper limit on the noise sources for our system that matches well with the noise spectrum of the magnetometer at frequencies above 5 Hz.

A microfabricated optically-pumped magnetic gradiometer.

We report on the development of a microfabricated atomic magnetic gradiometer based on optical spectroscopy of alkali atoms in the vapor phase. The gradiometer, which operates in the spin-exchange relaxation free regime, has a length of 60 mm and cross sectional diameter of 12 mm, and consists of two chip-scale atomic magnetometers which are interrogated by a common laser light. The sensor can measure differences in magnetic fields, over a 20 mm baseline, of 10 fT/[Formula: see text] at frequencies above 20 Hz. The maximum rejection of magnetic field noise is 1000 at 10 Hz. By use of a set of compensation coils wrapped around the sensor, we also measure the sensor sensitivity at several external bias field strengths up to 150 mG. This device is useful for applications that require both sensitive gradient field information and high common-mode noise cancellation.

Long-term side effects on the temporomandibular joints and oro-facial function in patients with obstructive sleep apnoea treated with a mandibular advancement device.

Patients with obstructive sleep apnoea (OSA) in long-term treatment with a mandibular advancement device (MAD) to increase the upper airway space may develop changes in the temporomandibular joint (TMJ) and the oro-facial function due to the protruded jaw position during sleep. The aim was to investigate the influence of long-term MAD treatment on the TMJs, oro-facial function and occlusion. This prospective study included 30 men and 13 women (median age 54) with OSA [Apnoea-Hypopnoea Index (AHI): 7-57]. They were examined with the Nordic Orofacial Test Screening (NOT-S), the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) and cone beam computed tomography (CBCT) of the TMJs. The examination was performed before MAD treatment (T0), and 3-6 months (T1, no CBCT), 1 year (T2) and 3 years (T3) after treatment start. The results were analysed as long term (T0-T3, n = 14) and short term (T0-T2, n = 24) by t-test, Fisher's exact test and anova. Both long- and short-term analyses revealed a reduction in AHI (P < 0·002). Significant long term were increased scores in the NOT-S Interview (P < 0·045), reduced vertical overbite (P < 0·031) and increased jaw protrusive movement (P < 0·027). TMJ changes were found as joint sounds in terms of reciprocal clicking and crepitus, short term as a decrease and subsequent recurrence (P < 0·053; P < 0·037). No significant radiological changes were found. In conclusion, MAD treatment is beneficial to some OSA patients, but might induce changes in the TMJs, the oro-facial function and the occlusion. However, these changes seemed to be less harmful than previously reported with careful adaptation, control and follow-ups.

[Mental disorders in women: Natural course during premenstrual phases, peripartum period and perimenopause]. / Psychische Störungen in den reproduktiven Phasen der Frau: Häufigkeiten, Verlauf und Besonderheiten.

Epidemiological studies indicate sex-specific differences in prevalence rates and the natural course of mental disorders. Affective, anxiety, somatoform and eating disorders are more prevalent in women than men, whereas substance use disorders occur more commonly in men, and some disorders are equally distributed in both sexes (e. g. psychotic disorders). The aim of this review is to depict the natural course of mental disorders during the reproductive stages (premenstrual phases, peripartum period, perimenopause) in women, including also neuroendocrine features associated with the menstrual cycle, pregnancy, puerperium and perimenopause. Recommendations for sex-specific diagnostic and therapeutic procedures are provided.

An optically modulated zero-field atomic magnetometer with suppressed spin-exchange broadening.

We demonstrate an optically pumped (87)Rb magnetometer in a microfabricated vapor cell based on a zero-field dispersive resonance generated by optical modulation of the (87)Rb ground state energy levels. The magnetometer is operated in the spin-exchange relaxation-free regime where high magnetic field sensitivities can be achieved. This device can be useful in applications requiring array-based magnetometers where radio frequency magnetic fields can induce cross-talk among adjacent sensors or affect the source of the magnetic field being measured.

The state of the art in European research on reducing social exclusion and stigma related to mental health: a systematic mapping of the literature.

Stigma and social exclusion related to mental health are of substantial public health importance for Europe. As part of ROAMER (ROAdmap for MEntal health Research in Europe), we used systematic mapping techniques to describe the current state of research on stigma and social exclusion across Europe. Findings demonstrate growing interest in this field between 2007 and 2012. Most studies were descriptive (60%), focused on adults of working age (60%) and were performed in Northwest Europe-primarily in the UK (32%), Finland (8%), Sweden (8%) and Germany (7%). In terms of mental health characteristics, the largest proportion of studies investigated general mental health (20%), common mental disorders (16%), schizophrenia (16%) or depression (14%). There is a paucity of research looking at mechanisms to reduce stigma and promote social inclusion, or at factors that might promote resilience or protect against stigma/social exclusion across the life course. Evidence is also limited in relation to evaluations of interventions. Increasing incentives for cross-country research collaborations, especially with new EU Member States and collaboration across European professional organizations and disciplines, could improve understanding of the range of underpinning social and cultural factors which promote inclusion or contribute toward lower levels of stigma, especially during times of hardship.

Structure-activity relationship of the pro- and anticoagulant effects of Fucus vesiculosus fucoidan.

Fucoidan is a highly complex sulfated polysaccharide commonly extracted from brown seaweed. In addition to their many biological activities, fucoidans have recently been demonstrated to inhibit or increase coagulation at different concentration ranges. Their structural features, i.e. molecular weight (Mw), Mw distribution, degree of sulfation, monosaccharide composition, and different linkages, are known to affect these activities. Therefore, structure-activity relationship (SAR) analysis of fucoidan is crucial for its potential use as a procoagulant. In this study, Fucus vesiculosus (F.v.) fucoidan was fractionated by charge and size as well as over- and desulfated to different degrees to yield preparations with various structural properties. The fractions' pro- and anticoagulant activities were assessed by calibrated automated thrombography (CAT) and activated partial thromboplastin time(aPTT) assays. Binding to and inhibition of the anticoagulant protein tissue factor pathway inhibitor (TFPI) and the ability to activate coagulation via the contact pathway were also investigated. This paper discusses the impact of charge density, size, and sugar composition on fucoidan's pro- and anticoagulant activities. Fucoidan requires a minimal charge density of 0.5 sulfates per sugar unit and a size of 70 sugar units to demonstrate desired procoagulant activities for improvement of haemostasis in factor VIII/factor IX-deficient plasma.

Dimensional anxiety scales for DSM-5: sensitivity to clinical severity.

PURPOSE: Psychometric properties and clinical sensitivity of brief self-rated dimensional scales to supplement categorical diagnoses of anxiety disorders in the DSM-5 were recently demonstrated in a German treatment seeking sample of adults. The present study aims to demonstrate sensitivity of these scales to clinical severity levels. METHODS: The dimensional scales were administered to 102 adults at a university outpatient clinic for psychotherapy. Diagnostic status was assessed using the Munich-Composite International Diagnostic Interview. To establish a wide range of clinical severity, we considered subthreshold (n=83) and threshold anxiety disorders (n=49, including Social Phobia, Specific Phobia, Agoraphobia, Panic Disorder, and Generalized Anxiety Disorder). RESULTS: Individuals with either subthreshold or threshold anxiety disorder scored higher on all dimensional scales relative to individuals without anxiety. In addition, individuals with a threshold anxiety disorder scored higher on the dimensional scales than individuals with a subthreshold anxiety disorder (except for specific phobia). Disorder-related impairment ratings, global functioning assessments and number of panic attacks were associated with higher scores on dimensional scales. Findings were largely unaffected by the number of anxiety disorders and comorbid depressive disorders. CONCLUSION: The self-rated dimensional anxiety scales demonstrated sensitivity to clinical severity, and a cut-off based on additional assessment of impairment and distress may assist in the discrimination between subthreshold and threshold anxiety disorders. Findings suggest further research in various populations to test the utility of the scales for use in DSM-5.

[Development of oculoplastic surgery in Kinshasa (capital of Democratic Republic of Congo)]. / Entwicklung der okuloplastischen Chirurgie in Kinshasa (Hauptstadt der Demokratischen Republik Kongo).

The partnership between Saint Joseph Hospital in Kinshasa (Capital city of DRC) and University Eye Clinic Rostock, Germany exists since 2000. The ophthalmologists from Rostock University performed 12 visits of St. Josef Hospital with the aim to perform oculoplastic surgery in complicated cases as well as to teach the local ophthalmologists. There they performed about 150 surgeries (entropion, ectropion, ptosis, repair of lid injuries, eye lid reconstruction and tumour management, lacrimal surgery) in joint teams. The programme of on-site training was established during this time. Meanwhile, the Kinshasa colleagues are able to perform the basic techniques by themselves. Two colleagues have obtained advanced training in oculoplastics in Rostock. The fruitful cooperation enabled the development of oculoplastic surgery in St. Josef Hospital in Kinshasa. The further education and training proccesses will support the continuous advancement in ophthalmological health care in DRC.

[Diabetic retinopathy and diabetic foot syndrome in patients of a sub-Saharan megacity (Kinshasa, DR Congo)]. / Diabetische Retinopathie und diabetisches Fußsyndrom bei Diabetikern in Kinshasa (Demokratische Republik Kongo).

PURPOSE: The prevalence of diabetes mellitus is increasing worldwide especially in developing countries. Foot ulcerations in patients with diabetic neuropathy have a high impact in the overall amputation rate. In the present study we looked for the severity of diabetic retinopathy in patients with diabetic foot syndrome in a diabetic care unit in a sub-Sahara megacity (Kinshasa, Democratic Republic of Congo). METHOD: Forty-one patients with diabetes-related foot ulcerations (26 male, 15 female, mean age 45.6 years) were enrolled in the study. All patients underwent visual acuity evaluation and slit lamp biomicroscopy. Incidence and stage of retinopathy were evaluated by retinal funduscopy and documented by fundus photography. RESULTS: Twenty-seven eyes showed no signs of diabetic retinopathy. Forty-seven eyes were diagnosed as non-proliferative diabetic retinopathy (16 mild, 16 moderate, 15 severe). Seven eyes showed proliferative diabetic retinopathy. One patient had a unilateral central venous occlusion. In this case the classification of diabetic retinopathy was not possible because of the massive retinal bleedings. CONCLUSION: It was evident that there is a considerable discrepancy between partly extensive foot ulcerations and only mild to moderate diabetic retinopathy in most of the patients. This indicates that neuropathy-induced foot problems and microangiopathy-induced diabetic retinopathy are diabetic complications whose formal pathogenesis is only loosely correlated. Additional risk factors in local African conditions compared to Europe may play a major role in this discrepancy.

The natural course of social anxiety disorder among adolescents and young adults.

OBJECTIVE: To examine the natural course of social anxiety disorder (SAD) in the community and to explore predictors for adverse long-term outcomes. METHOD: A community sample of N = 3021 subjects aged 14-24 was followed-up over 10 years using the DSM-IV/M-CIDI. Persistence of SAD is based on a composite score reflecting the proportion of years affected since onset. Diagnostic stability is the proportion of SAD subjects still affected at follow-up. RESULTS: SAD reveals considerable persistence with more than half of the years observed since onset spent with symptoms. 56.7% of SAD cases revealed stability with at least symptomatic expressions at follow-up; 15.5% met SAD threshold criteria again. 15.1% were completely remitted (no SAD symptoms and no other mental disorders during follow-up). Several clinical features (early onset, generalized subtype, more anxiety cognitions, severe avoidance and impairment, co-occurring panic) and vulnerability characteristics (parental SAD and depression, behavioural inhibition, harm avoidance) predicted higher SAD persistence and - less impressively - diagnostic stability. CONCLUSION: A persistent course with a considerable degree of fluctuations in symptom severity is characteristic for SAD. Both consistently meeting full threshold diagnostic criteria and complete remissions are rare. Vulnerability and clinical severity indicators predict poor prognosis and might be helpful markers for intervention needs.

Magnetoencephalography with a chip-scale atomic magnetometer.

We report on the measurement of somatosensory-evoked and spontaneous magnetoencephalography (MEG) signals with a chip-scale atomic magnetometer (CSAM) based on optical spectroscopy of alkali atoms. The uncooled, fiber-coupled CSAM has a sensitive volume of 0.77 mm(3) inside a sensor head of volume 1 cm(3) and enabled convenient handling, similar to an electroencephalography (EEG) electrode. When positioned over O1 of a healthy human subject, α-oscillations were observed in the component of the magnetic field perpendicular to the scalp surface. Furthermore, by stimulation at the right wrist of the subject, somatosensory-evoked fields were measured with the sensors placed over C3. Higher noise levels of the CSAM were partly compensated by higher signal amplitudes due to the shorter distance between CSAM and scalp.

The association between social phobia, social anxiety cognitions and paranoid symptoms.

OBJECTIVE: Previous research suggests high levels of comorbidity between social phobia and paranoid symptoms, although the nature of this association remains unclear. METHOD: Data were derived from the Early Developmental Stages of Psychopathology study, a 10-year longitudinal study in a representative German community sample of 3021 participants aged 14-24 years at baseline. The Munich-Composite International Diagnostic Interview was used to assess social phobia and paranoid symptoms, along with data on social phobia features. Cross-sectional and longitudinal analyses were conducted. Differential associations with environmental risk factors and temperamental traits were investigated. RESULTS: Lifetime social phobia and paranoid symptoms were associated with each other cross-sectionally (OR = 1.80, 95% CI = 1.31-2.47). Lifetime paranoid symptoms were associated specifically with social anxiety cognitions. Lifetime cognitions of negative evaluation predicted later onset of paranoid symptoms, whereas onset of social phobia was predicted by cognitions of loss of control and fear/avoidance of social situations. Lifetime social phobia and paranoid symptoms shared temperamental traits of behavioural inhibition, but differed in environmental risks. CONCLUSIONS: The present study showed that paranoid symptoms and social phobia share similarities in cognitive profile and inhibited temperament. Avoidance appears to be important in the development of social phobia, whereas cannabis use and traumatic experiences may drive paranoid thinking in vulnerable individuals.

Optical isolator using an atomic vapor in the hyperfine Paschen-Back regime.

A light, compact optical isolator using an atomic vapor in the hyperfine Paschen-Back regime is presented. Absolute transmission spectra for experiment and theory through an isotopically pure 87Rb vapor cell show excellent agreement for fields of 0.6 T. We show π/4 rotation for a linearly polarized beam in the vicinity of the D2 line and achieve an isolation of 30 dB with a transmission >95%.

Note: Detection of a single cobalt microparticle with a microfabricated atomic magnetometer.

We present magnetic detection of a single, 2 µm diameter cobalt microparticle using an atomic magnetometer based on a microfabricated vapor cell. These results represent an improvement by a factor of 10(5) in terms of the detected magnetic moment over previous work using atomic magnetometers to detect magnetic microparticles. The improved sensitivity is due largely to the use of small vapor cells. In an optimized setup, we predict detection limits of 0.17 µm(3).

Small-sized dichroic atomic vapor laser lock.

Two, lightweight diode laser frequency stabilization systems designed for experiments in the field are described. A significant reduction in size and weight in both models supports the further miniaturization of measurement devices in the field. Similar to a previous design, magnetic field lines are contained within a magnetic shield enclosing permanent magnets and a Rb cell, so that these dichroic atomic vapor laser lock (DAVLL) systems may be used for magnetically sensitive instruments. The mini-DAVLL system (49 mm long) uses a vapor cell (20 mm long) and does not require cell heaters. An even smaller micro-DAVLL system (9 mm long) uses a microfabricated cell (3 mm square) and requires heaters. These new systems show no degradation in performance with regard to previous designs while considerably reducing dimensions.

[Progressive corneal opacity after autologous keratoplasty]. / Progrediente Hornhauttrübung nach autologer Keratoplastik. Diagnose: Epitheliale Zellaussaat in die Vorderkammer nach autologer Keratoplastik.

A 55-year-old woman underwent autologous keratoplasty because of band keratopathy and corneal decompensation of the left eye. Previously recurring events of uveitis had affected the eye. A vitrectomy had been performed on the left side for tractional retinal detachment of the posterior pole. The visual acuity of the right donor eye had been reduced to hand movements after occlusion of the central retinal artery. Twelve months after the transplantation, a circumscribed opacity appeared on the endothelial side of the cornea. Cells in the anterior chamber were detected, as well as a moderate rise in ocular tension. Despite intensive anti-inflammatory therapy, the membrane extended over the complete cornea. We diagnosed an ingrowth of epithelial cells as responsible for the changes.

Optical detection of NMR J-spectra at zero magnetic field.

Scalar couplings of the form JI(1) x I(2) between nuclei impart valuable information about molecular structure to nuclear magnetic-resonance spectra. Here we demonstrate direct detection of J-spectra due to both heteronuclear and homonuclear J-coupling in a zero-field environment where the Zeeman interaction is completely absent. We show that characteristic functional groups exhibit distinct spectra with straightforward interpretation for chemical identification. Detection is performed with a microfabricated optical atomic magnetometer, providing high sensitivity to samples of microliter volumes. We obtain 0.1 Hz linewidths and measure scalar-coupling parameters with 4-mHz statistical uncertainty. We anticipate that the technique described here will provide a new modality for high-precision "J spectroscopy" using small samples on microchip devices for multiplexed screening, assaying, and sample identification in chemistry and biomedicine.

Zero-field remote detection of NMR with a microfabricated atomic magnetometer.

We demonstrate remote detection of nuclear magnetic resonance (NMR) with a microchip sensor consisting of a microfluidic channel and a microfabricated vapor cell (the heart of an atomic magnetometer). Detection occurs at zero magnetic field, which allows operation of the magnetometer in the spin-exchange relaxation-free (SERF) regime and increases the proximity of sensor and sample by eliminating the need for a solenoid to create a leading field. We achieve pulsed NMR linewidths of 26 Hz, limited, we believe, by the residence time and flow dispersion in the encoding region. In a fully optimized system, we estimate that for 1 s of integration, 7 x 10(13) protons in a volume of 1 mm(3), prepolarized in a 10-kG field, can be detected with a signal-to-noise ratio of approximately 3. This level of sensitivity is competitive with that demonstrated by microcoils in 100-kG magnetic fields, without requiring superconducting magnets.