Polycystic ovary syndrome and offspring risk of congenital heart defects: a nationwide cohort study.

STUDY QUESTION: Is maternal polycystic ovary syndrome (PCOS) associated with increased offspring risk of congenital heart defects? SUMMARY ANSWER: This study does not support a strong association between PCOS and an increased risk of congenital heart defects. WHAT IS KNOWN ALREADY: In addition to affecting reproductive health, PCOS may involve insulin resistance. Maternal pregestational diabetes is associated with an increased risk of congenital heart defects and therefore PCOS may increase the risk of congenital heart defects in the offspring. STUDY DESIGN, SIZE, DURATION: In this nationwide cohort study, we used data from Danish health registers collected from 1995 to 2018. The study included 1 302 648 offspring and their mothers. PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants were live singleton offspring born during the study period. Information on maternal PCOS and offspring congenital heart defects was obtained from the National Patient Register. Logistic regression analysis was used to compute prevalence (odds) ratio (PR) of the association between PCOS and offspring congenital heart defects. MAIN RESULTS AND THE ROLE OF CHANCE: Among 1 302 648 live-born singletons, 11 804 had a mother with PCOS. Of these, 143 offspring had a congenital heart defect (prevalence 121 per 10 000) as compared with 12 832 among mothers without PCOS (prevalence 99 per 10 000). The adjusted PR was 1.22, 95% CI 1.03-1.44 comparing prevalence of congenital heart defects in offspring of women with PCOS with offspring of women without. After adjusting for the potentially mediating effect of pregestational diabetes, the PR was 1.16, 95% CI 0.98-1.37. LIMITATIONS, REASONS FOR CAUTION: PCOS may be underdetected in the National Patient Register. However, we expect that the mothers that we identified with PCOS truly had PCOS, thus, the estimated associations are not likely to be affected by this misclassification. The study does not provide evidence to rule out a moderate or weak association. WIDER IMPLICATIONS OF THE FINDINGS: These findings provide reassurance to clinicians counselling pregnant women with PCOS that the disease does not pose a markedly increased risk of offspring congenital heart defects. STUDY FUNDING/COMPETING INTEREST(S): The study was funded by the Novo Nordisk Foundation. M.L. reports personal fees from Dansk Lægemiddel Information A/S outside the submitted work. The remaining authors have no conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.

Ambiguity of experimental spin information from states with mixed orbital symmetries.

The spin texture of the unoccupied bands of the surface alloy Bi/Ag(111) is investigated with spin- and angle-resolved inverse photoemission and first-principles calculations. Surprisingly, the measured spin character does not always reflect the calculated spin texture of the bands. With the help of photoemission calculations within the one-step model, however, the discrepancy is traced back to the influence of the orbital symmetry of the respective states in combination with the experimental geometry. In particular, the calculations show that the spin texture of a surface band with mixed orbital symmetries may neither be recovered with s- nor p- nor unpolarized light. In general, spin information from direct or inverse photoemission experiments on electronic states with mixed orbital symmetries at spin-orbit-influenced surfaces has to be taken with a pinch of salt, while it remains reliable for states with pure symmetry.

Role of spin-flip exchange scattering for hot-electron lifetimes in cobalt.

The spin-dependent lifetimes of hot electrons in fcc Co films were studied by spin- and time-resolved two-photon photoemission. Even for excitation energies close to the Fermi level, we find almost identical lifetimes for majority and minority electrons. This result contradicts ab initio theories predicting 5 to 10 times longer lifetimes for the majority electrons in 3d ferromagnets. We provide direct experimental evidence that this discrepancy is caused by the dominance of exchange scattering in inelastic electron decay, in combination with the excitation of secondary electrons. The latter are inherent for all real materials and devices.

Magnetic exchange splitting in Fe above the Curie temperature.

The magnetic exchange splitting of electronic states in a 7 monolayer Fe film on Cu(001) was investigated below and above the Curie temperature T(C), using image-potential surface states as sensor. At T(C), the long-range magnetic order breaks down as reflected by a vanishing spin splitting and vanishing spin polarization. The exchange splitting, in contrast, does not change abruptly at T(C) but persists up to T=1.2T(C). Equally, the spin-integrated linewidth shows no signature of the magnetic phase transition but smoothly decreases with increasing temperature. Our experimental results confirm theoretical expectations that, at T(C), the long-range magnetic order disappears but the local magnetic moments and, in particular, the valence electronic structure are unaffected by the phase transition.

Ultrafast magnon generation in an Fe film on Cu(100).

We report on a combined experimental and theoretical study of the spin-dependent relaxation processes in the electron system of an iron film on Cu(100). Spin-, time-, energy- and angle-resolved two-photon photoemission shows a strong characteristic dependence of the lifetime of photoexcited electrons on their spin and energy. Ab initio calculations as well as a many-body treatment corroborate that the observed properties are determined by relaxation processes involving magnon emission. Thereby we demonstrate that magnon emission by hot electrons occurs on the femtosecond time scale and thus provides a significant source of ultrafast spin-flip processes. Furthermore, engineering of the magnon spectrum paves the way for tuning the dynamic properties of magnetic materials.

Ferromagnetic Fe on Cu(001) throughout the fcc-like phase: arguing from the viewpoint of the electronic structure.

The scientific enthusiasm for ultrathin Fe films on Cu(001) has now lasted for more than 20 years. Is there ferromagnetic iron with a face-centred cubic (fcc) structure? Does ferromagnetism in Fe hinge on the body-centred cubic (bcc) structure? In this contribution, we try to establish that the electron system gives evidence of ferromagnetic behaviour with fcc-like electronic bands. We examine a crystal-induced surface state, which is characteristic of fcc surface order. Furthermore, we compare electronic signatures of fcc and bcc: the d-band exchange splitting, image-potential-state energies and the work function. We conclude that, from the viewpoint of the electronic structure, Fe on Cu(001) is found to be ferromagnetic throughout the fcc-like phase. This result raises a new question: how much deviation from the relaxed fcc order is acceptable without losing the electronic signature of fcc?

Liquid-state carbon-13 hyperpolarization generated in an MRI system for fast imaging.

Hyperpolarized (HP) tracers dramatically increase the sensitivity of magnetic resonance imaging (MRI) to monitor metabolism non-invasively and in vivo. Their production, however, requires an extra polarizing device (polarizer) whose complexity, operation and cost can exceed that of an MRI system itself. Furthermore, the lifetime of HP tracers is short and some of the enhancement is lost during transfer to the application site. Here, we present the production of HP tracers in water without an external polarizer: by Synthesis Amid the Magnet Bore, A Dramatically Enhanced Nuclear Alignment (SAMBADENA) is achieved within seconds, corresponding to a hyperpolarization of ∼20%. As transfer of the tracer is no longer required, SAMBADENA may permit a higher polarization at the time of detection at a fraction of the cost and complexity of external polarizers. This development is particularly promising in light of the recently extended portfolio of biomedically relevant para-hydrogen-tracers and may lead to new diagnostic applications.

Do twisted laser beams evoke nuclear hyperpolarization?

The hyperpolarization of nuclear spins promises great advances in chemical analysis and medical diagnosis by substantially increasing the sensitivity of nuclear magnetic resonance (NMR). Current methods to produce a hyperpolarized sample, however, are arduous, time-consuming or costly and require elaborate equipment. Recently, a much simpler approach was introduced that holds the potential, if harnessed appropriately, to revolutionize the production of hyperpolarized spins. It was reported that high levels of hyperpolarization in nuclear spins can be created by irradiation with a laser beam carrying orbital angular momentum (twisted light). Aside from these initial reports however, no further experimental verification has been presented. In addition, this effect has so far evaded a critical theoretical examination. In this contribution, we present the first independent attempt to reproduce the effect. We exposed a sample of immersion oil or a fluorocarbon liquid that was placed within a low-field NMR spectrometer to Laguerre-Gaussian and Bessel laser beams at a wavelength of 514.5nm and various topological charges. We acquired (1)H and (19)F NMR free induction decay data, either during or alternating with the irradiation that was parallel to B0. We observed an irregular increase in NMR signal in experiments where the sample was exposed to beams with higher values of the topological charge. However, at no time did the effect reach statistical significance of 95%. Given the measured sensitivity of our setup, we estimate that a possible effect did not exceed a hyperpolarization (at 5mT) of 0.14-6%, depending on the assumed hyperpolarized volume. It should be noted though, that there were some differences between our setup and the previous implementation of the experiment, which may have inhibited the full incidence of this effect. To approach a theoretical description of this effect, we considered the interaction of an electron with a plane wave, which is known to be able to induce electronic (e.g. in rubidium) and subsequent nuclear hyperpolarization. Compared to the plane wave, the additional transitions caused by a twisted wave are of the order of 10(-3) less. This suggests that the twist of the laser is unlikely to be responsible for the hyperpolarization of nuclear spins, unless a new mechanism of momentum transfer is identified.

Momentum resolution in inverse photoemission.

We present a method to determine the electron beam divergence, and thus the momentum resolution, of an inverse-photoemission setup directly from a series of spectra measured on Cu(111). Simulating these spectra with different beam divergences shows a distinct influence of the divergence on the appearance of the Shockley surface state. Upon crossing the Fermi level, its rise in intensity can be directly linked with the beam divergence. A comparison of measurement and simulation enables us to quantify the momentum resolution independent of surface quality, energy resolution, and experimental geometry. With spin resolution, a single spectrum taken around the Fermi momentum of a spin-split surface state, e.g., on Au(111), is sufficient to derive the momentum resolution of an inverse-photoemission setup.

Size effects in nonpolar solvation: lessons from two simple models.

Size dependence of the solute chemical potential mu(u) is examined using the Ornstein-Zernike equation for two models of the nonpolar solute-solvent interactions. Simple Lennard-Jones interactions are assumed in the first model while the Lennard-Jones potential is distributed over the solute volume in the second model similar to the Hamaker theory for the colloid dispersion forces. In both models, while mu(u) rises asymptotically as the third power of the solute size in agreement with asymptotic solution of the scaled particle theory, it increases faster at smaller sizes. Deviations from the cubic law are more pronounced at higher solvent densities and stronger molecular interactions. Within a relatively narrow size range typical for small organic molecules, mu(u) can be approximated with a polynomial of the third or even the second power. However, the latter approximation is less accurate and cannot be employed for extrapolation to the larger size region.

Brazilian population database for the 13 STR loci of the AmpFlSTR Profiler Plus and Cofiler multiplex kits.

Allele frequencies for the 13 STR core loci (D3S1358, VWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820, CSF1PO, TPOX, THO1 and D16S539) included in the AmpFlSTR((R)) Profiler Plus and AmpFlSTR((R)) Cofiler kits were obtained for a sample of 700-800 genetically unrelated Brazilians. The expected performance of these loci for personal identification and paternity testing in the Brazilian population was estimated.

The magnitude of osteoporosis in middle aged women.

OBJECTIVE: This study aims to increase the body of knowledge regarding osteoporosis in the Jordanian context by investigating the magnitude of osteoporosis amongst perimenopausal women, as well as the risk factors associated with the disease. METHODS: Two hundred and fifty one women between the ages of 40 to 60 years were randomly selected from the Orthopedics and Rheumatology out patient clinics at the Major Teaching Hospital in Amman, Jordan. A structured questionnaire, which focused upon risk factors and preventive measures for osteoporosis, was administered by a trained staff nurse to all women. Index women were then referred to a private hospital, also in Amman, for a dual energy x-ray absorptiometry of the lumbar spine (Lumbar 1-4) and hip. RESULTS: Results show the magnitude of osteoporosis was 13% according to the bone mineral density of the lumbar spine. Women with osteoporosis were older (p< 0.00) and smaller in build (p<0.00) than women with low or normal bone density. Osteoporotic women were also more likely to be menopausal (p<0.00) and to have taken corticosteroids for a prolonged period of time (p<0.00). Logistic regression showed being menopausal (p<0.00), taking corticosteroids (p<0.05), and having a relatively lower body mass index (p<0.00) were significantly related to being osteoporotic in this group of women. CONCLUSION: The authors conclude that this study was not only able to report upon the magnitude of osteoporosis among women sampled, and the risk factors for low bone density, but also raised issues related to inconsistencies in how the health care system deals with women who are at risk for osteoporosis. Study findings are discussed in their socio-cultural context, and implications of the study findings are presented.

Rotatable spin-polarized electron source for inverse-photoemission experiments.

We present a ROtatable Spin-polarized Electron source (ROSE) for the use in spin- and angle-resolved inverse-photoemission (SR-IPE) experiments. A key feature of the ROSE is a variable direction of the transversal electron beam polarization. As a result, the inverse-photoemission experiment becomes sensitive to two orthogonal in-plane polarization directions, and, for nonnormal electron incidence, to the out-of-plane polarization component. We characterize the ROSE and test its performance on the basis of SR-IPE experiments. Measurements on magnetized Ni films on W(110) serve as a reference to demonstrate the variable spin sensitivity. Moreover, investigations of the unoccupied spin-dependent surface electronic structure of Tl/Si(111) highlight the capability to analyze complex phenomena like spin rotations in momentum space. Essentially, the ROSE opens the way to further studies on complex spin-dependent effects in the field of surface magnetism and spin-orbit interaction at surfaces.

[Muscular and osteomuscular peroneus brevis flaps]. / Die Musculus-peroneus-brevis-Lappenplastiken.

OBJECTIVE: Soft tissue defect reconstruction by transposition of well-vascularized muscle tissue with a muscle flap and as an osteomuscular flap together with a fibular bone segment for combined skeletal and soft tissue defects. INDICATIONS: Small- and medium-sized defects of the hindfoot, around the ankle and the distal and middle third of the lower leg, skeletal reconstruction of underlying small- and medium-sized bone defects. CONTRAINDICATIONS: Lesions of the proximal anterior tibial artery (proximal pedicled flap), combined lesions of the distal peroneal artery including the communicating branch with the posterior tibial artery (distal pedicled flap); lesion or paralysis of the peroneus longus muscle in an intact ankle joint. SURGICAL TECHNIQUE: Distally pedicled flap: blunt separation between the peroneus longus and brevis muscle, subperiosteal release with isolation on a distal septocutaneous branch of the peroneal artery. To increase perfusion, the proximally released branch of the anterior tibial artery may be re-anastomosed in the recipient site. Proximally pedicled flap: dissection of distal peroneus brevis muscle tendon and subperiosteal release in a proximal direction with ligation of the segmental peroneal artery branches until the flap is isolated on its proximal anterior tibial artery branch. For an osteomuscular flap, simultaneous harvest of a fibula segment underneath the muscle origin with preservation of the intimate periosteal relationship between muscle and bone. POSTOPERATIVE MANAGEMENT: Complete immobilization and elevated leg position for 5 days, followed by successive orthostatic training for 10 days. Postoperative standardized compression garments for 6 months, eventually combined with silicone sheet scar therapy. RESULTS: Reliable, excellent functional and aesthetic results with very low donor site morbidity.

Clampless anastomosis with an intraluminal thermosensitive gel: first application in reconstructive microsurgery and literature review.

Microvascular clamps of various designs provide a bloodless field for a safe anastomosis but can cause intimal lesions, occupy space in confined sites and have a risk of backwalling due to vessel flattening. They are often insufficient in their haemostatic effect in plaque-filled atherosclerotic vessels. A new, CE-certified thermosensitive gel (LeGoo™) clinically proven in cardiovascular surgery allows a clampless microanastomosis technique. We operated on a series of five consecutive patients aged 24-71 years with six flaps for lower-extremity reconstruction using a clampless anastomosis technique with LeGoo™. We transplanted one fabricated chimaeric fibula plus gracilis, three gracilis muscle and one anterolateral thigh (ALT) flap. Pre- and postoperative protocols were similar to a 'standard' procedure with micro-clamps. All flaps survived completely except for a small area on fibula skin island, which was unrelated to gel use. The gel-assisted technique has a quick learning curve, according to this case series. The veins should be sutured first to prevent stasis in the flap. The gel provides circular stenting and gentle distension of the vessels for a safe and blood-free anastomotic site. It is completely dissolved after completion of the anastomosis with cold saline irrigation. Repolymerisation in the periphery will not occur, making it safe for microvascular flap surgery. From the experiences from this series and other specialities, the use of the thermosensitive gel LeGoo™ permits a safe clampless microanastomosis technique minimising mechanical vessel manipulation and compression. This makes it an attractive alternative to micro-clamps, especially for atherosclerotic arteries and confined anastomosis sites.

Spin-orbit hybridization points in the face-centered-cubic cobalt band structure.

Linear magnetic dichroism is observed in spin-, time-, and energy-resolved two-photon photoemission from valence bands of epitaxial fcc cobalt on Cu(001). With image-potential states as spectator states we identify initial bulk and surface states with minority spin character as the source for dichroic intensities and apparent dichroic lifetimes. Excellent agreement with ab initio fully relativistic calculations of the cobalt fcc band structure allows us to precisely determine spin-orbit hybridization points close to the Fermi level. These spin hot spots enhance spin-flip scattering by several orders of magnitude and are therefore assumed to be crucial in ultrafast demagnetization.

Applicability of a continuum solvation model to the octanol water transfer: CFF91 based model for amino acids.

A continuum hydration model based upon the atomic charges provided with the CFF91 force field [A. B. Schmidt and R. M. Fine (1994) Molecular Simulation, 13, 347-365] has been extended to the octanol-water transfer. The electrostatic component of the transfer free energy is calculated using the finite-difference solution to the Poisson-Boltzmann equation while the nonpolar contributions are assumed to be proportional to the solute-excluded volume in water. All atomic charges and radii besides the aromatic carbon radius are equal in both solvents. The octanol dielectric constant and the probe radius are the main fitting parameters defining the octanol phase. The model has been tested for 38 organic molecules related to the amino acid residues and generally provides a high accuracy. In particular, the mean unsigned error for N-acetyl amino acid amides is 0.5 kcal/mol.

Applications of the pedicled vastus lateralis flap for patients with complicated pressure sores.

The vastus lateralis muscle- or musculocutaneous flap is a well established tool in the surgery of pressure sores of the pelvic region. Its size, its constant large axial vascular pedicle originating from the lateral circumflex femoral artery, and its ability to carry quite a large skin island from the distal lateral region of the upper thigh makes this flap a very versatile one in the management of difficult situations. The vastus lateralis flap allows the simultaneous closure of defects in the trochanteric and sacral region, a technique which has not been described previously. A pedicled vastus lateralis flap may be the only remaining local salvage procedure for defects due to obstruction of internal and external iliac arteries and aortobifemoral bypass surgery. This is another application which has not yet been described in the medical literature. The outcome of a series of 38 vastus lateralis flaps and the complications are shown. The follow-up period ranged from 3 months to 4 years. One flap was lost. More complications were seen at the donor site than at the reconstructed defect. In patients who may be able to walk or stand at a later date, potential impairment of these functions has to be considered. In our opinion, the vastus lateralis flap is an excellent tool for managing large tissue defects in difficult situations.