An ESPGHAN Position Paper on the Use of Low-FODMAP Diet in Pediatric Gastroenterology.

Excluding oligo-, di-, monosaccharides and polyols (FODMAPs) from the diet is increasingly being used to treat children with gastrointestinal complaints. The aim of this position paper is to review the available evidence on the safety and efficacy of its use in children and provide expert guidance regarding practical aspects in case its use is considered . Members of the Gastroenterology Committee, the Nutrition Committee and the Allied Health Professionals Committee of the European Society for Pediatric Gastroenterology Hepatology and Nutrition contributed to this position paper. Clinical questions regarding initiation, introduction, duration, weaning, monitoring, professional guidance, safety and risks of the diet are addressed. A systematic literature search was performed from 2005 to May 2021 using PubMed, MEDLINE and Cochrane Database of Systematic Reviews. In the absence of evidence, recommendations reflect the expert opinion of the authors. The systematic literature search revealed that the low-FODMAP diet has not been comprehensively studied in children. Indications and contraindications of the use of the diet in different pediatric gastroenterological conditions are discussed and practical recommendations are formulated. There is scarce evidence to support the use of a low-FODMAP diet in children with Irritable Bowel Syndrome and no evidence to recommend its use in other gastrointestinal diseases and complaints in children. Awareness of how and when to use the diet is crucial, as a restrictive diet may impact nutritional adequacy and/or promote distorted eating in vulnerable subjects. The present article provides practical safety tips to be applied when the low-FODMAP diet is considered in children.

S2k guidelines (consensus statement) for diagnosis and therapy of dermatitis herpetiformis initiated by the European Academy of Dermatology and Venereology (EADV).

INTRODUCTION: Dermatitis herpetiformis (DH) is a chronic, pruritic, gluten-induced skin disorder characterized by subepidermal granular IgA deposition and a variable degree of enteropathy identical to that seen in coeliac disease. So far, there has been no European consensus about the management of DH. METHODS: The guidelines were created by small subgroups of a guideline committee consisting of 26 specialists from various medical fields and one patients' representative. The members of the committee then discussed the guidelines and voted for the final version at two consensus meetings. The guidelines were developed under the support of the European Academy of Dermatology and Venereology (EADV) and in collaboration with the European Dermatology Forum (EDF). RESULTS: The guidelines summarize evidence-based and expert-based recommendations (S2 level) for the management of DH (see Appendix). CONCLUSION: These guidelines will improve the quality of management of DH and support dermatologists in their diagnostic and therapeutic decisions.

A Systematic Review and Meta-analysis of Paediatric Inflammatory Bowel Disease Incidence and Prevalence Across Europe.

BACKGROUND AND AIMS: Inflammatory bowel disease [IBD] is often one of the most devastating and debilitating chronic gastrointestinal disorders in children and adolescents. The main objectives here were to systematically review the incidence and prevalence of paediatric IBD across all 51 European states. METHODS: We undertook a systematic review and meta-analysis based on PubMed, CINAHL, the Cochrane Library, searches of reference lists, grey literature and websites, covering the period from 1970 to 2018. RESULTS: Incidence rates for both paediatric Crohn's disease [CD] and ulcerative colitis [UC] were higher in northern Europe than in other European regions. There have been large increases in the incidence of both paediatric CD and UC over the last 50 years, which appear widespread across Europe. The largest increases for CD have been reported from Sweden, Wales, England, the Czech Republic, Denmark and Hungary, and for UC from the Czech Republic, Ireland, Sweden and Hungary. Incidence rates for paediatric CD have increased up to 9 or 10 per 100 000 population in parts of Europe, including Scandinavia, while rates for paediatric UC are often slightly lower than for CD. Prevalence reported for CD ranged from 8.2 per 100 000 to approximately 60 and, for UC, from 8.3 to approximately 30. CONCLUSIONS: The incidence of paediatric IBD continues to increase throughout Europe. There is stronger evidence of a north-south than an east-west gradient in incidence across Europe. Further prospective studies are needed, preferably multinational and based on IBD registries, using standardized definitions, methodology and timescales.

Human intestinal mucosa-associated Lactobacillus and Bifidobacterium strains with probiotic properties modulate IL-10, IL-6 and IL-12 gene expression in THP-1 cells.

Lactobacilli and bifidobacteria are considered one of the permanent genera of the physiological human intestinal microbiota and represent an enormous pool of potential probiotic candidates. Approximately 450 isolates of presumptive Lactobacillus or Bifidobacterium strains were obtained from bioptic samples of colonic and ileal mucosa from 15 adolescents aged 12 to 18 years. On the basis of randomly amplified polymorphic DNA (RAPD)-PCR analysis, 20 strains were selected for further taxonomic classification and characterisation, as well as assessment of probiotic properties and safety. Importantly, selected strains showed the capability of colonising different parts of the intestine. The most frequently isolated species was Lactobacillus paracasei followed by Lactobacillus fermentum. The majority of isolates were susceptible to antimicrobials of human and veterinary importance, however, tetracycline and/or erythromycin resistance was observed in Lactobacillus plantarum and L. fermentum strains. Thirteen strains were able to ferment more than 19 different carbon sources and three out of five tested strains exerted antagonistic activity against several different indicator strains. Two Lactobacillus isolates (L. paracasei L350 and L. fermentum L930 bb) and one Bifidobacterium isolate (Bifidobacterium animalis subsp. animalis IM386) fulfilled in vitro selection criteria for probiotic strains and exhibited strong downregulation of pro-inflammatory cytokines IL-6 and IL-12 and upregulation of anti-inflammatory IL-10. The selected strains represent suitable candidates for further studies regarding their positive influence on host health and could play an important role in ameliorating the symptoms of inflammatory bowel diseases.

Discovery of a superconducting high-entropy alloy.

High-entropy alloys (HEAs) are multicomponent mixtures of elements in similar concentrations, where the high entropy of mixing can stabilize disordered solid-solution phases with simple structures like a body-centered cubic or a face-centered cubic, in competition with ordered crystalline intermetallic phases. We have synthesized an HEA with the composition Ta34Nb33Hf8Zr14Ti11 (in at. %), which possesses an average body-centered cubic structure of lattice parameter a=3.36 Å. The measurements of the electrical resistivity, the magnetization and magnetic susceptibility, and the specific heat revealed that the Ta34Nb33Hf8Zr14Ti11 HEA is a type II superconductor with a transition temperature Tc≈7.3 K, an upper critical field µ0H_c2≈8.2 T, a lower critical field µ0Hc1≈32 mT, and an energy gap in the electronic density of states (DOS) at the Fermi level of 2Δ≈2.2 meV. The investigated HEA is close to a BCS-type phonon-mediated superconductor in the weak electron-phonon coupling limit, classifying it as a "dirty" superconductor. We show that the lattice degrees of freedom obey Vegard's rule of mixtures, indicating completely random mixing of the elements on the HEA lattice, whereas the electronic degrees of freedom do not obey this rule even approximately so that the electronic properties of a HEA are not a "cocktail" of properties of the constituent elements. The formation of a superconducting gap contributes to the electronic stabilization of the HEA state at low temperatures, where the entropic stabilization is ineffective, but the electronic energy gain due to the superconducting transition is too small for the global stabilization of the disordered state, which remains metastable.

Stabilization mechanism of γ-Mg17Al12 and ß-Mg2Al3 complex metallic alloys.

Large-unit-cell complex metallic alloys (CMAs) frequently achieve stability by lowering the kinetic energy of the electron system through formation of a pseudogap in the electronic density of states (DOS) across the Fermi energy εF. By employing experimental techniques that are sensitive to the electronic DOS in the vicinity of εF, we have studied the stabilization mechanism of two binary CMA phases from the Al-Mg system: the γ-Mg17Al12 phase with 58 atoms in the unit cell and the ß-Mg2Al3 phase with 1178 atoms in the unit cell. Since the investigated alloys are free from transition metal elements, orbital hybridization effects must be small and we were able to test whether the alloys obey the Hume-Rothery stabilization mechanism, where a pseudogap in the DOS is produced by the Fermi surface-Brillouin zone interactions. The results have shown that the DOS of the γ-Mg17Al12 phase exhibits a pronounced pseudogap centered almost exactly at εF, which is compatible with the theoretical prediction that this phase is stabilized by the Hume-Rothery mechanism. The disordered cubic ß-Mg2Al3 phase is most likely entropically stabilized at high temperatures, whereas at lower temperatures stability is achieved by undergoing a structural phase transition to more ordered rhombohedral ß' phase at 214 ° C, where all atomic sites become fully occupied. No pseudogap in the vicinity of εF was detected for the ß' phase on the energy scale of a few 100 meV as determined by the 'thermal observation window' of the Fermi-Dirac function, so that the Hume-Rothery stabilization mechanism is not confirmed for this compound. However, the existence of a much broader shallow pseudogap due to several critical reciprocal lattice vectors [Formula: see text] that simultaneously satisfy the Hume-Rothery interference condition remains the most plausible stabilization mechanism of this phase. At Tc = 0.85 K, the ß' phase undergoes a superconducting transition, which slightly increases the cohesive energy and may contribute to relative stability of this phase against competing neighboring phases.

PdGa intermetallic hydrogenation catalyst: an NMR and physical property study.

The PdGa intermetallic compound is a highly selective and stable heterogeneous hydrogenation catalyst for the semi-hydrogenation of acetylene. We have studied single crystals of PdGa grown by the Czochralski technique. The (69)Ga electric-field-gradient (EFG) tensor was determined by means of NMR spectroscopy, giving experimental confirmation of both the recently refined structural model of PdGa and the theoretically predicted Pd-Ga covalent bonding scheme. The hydrogenation experiment has detected no hydrogen uptake in the PdGa, thus preventing in situ hydride formation that leads to a reduction of the catalytic selectivity. We have also determined bulk physical properties (the magnetic susceptibility, the electrical resistivity, the thermoelectric power, the Hall coefficient, the thermal conductivity and the specific heat) of single-crystalline PdGa. The results show that PdGa is a diamagnet with metallic electrical resistivity and moderately high thermal conductivity. The thermoelectric power is negative with complicated temperature dependence, whereas the Hall coefficient is positive and temperature-dependent, indicating complexity of the Fermi surface. Partial fulfillment of the NMR Korringa relation reveals that the charge carriers are weakly correlated. Specific heat measurements show that the density of electronic states (DOS) at the Fermi energy of PdGa is reduced to 15% of the DOS of the elemental Pd metal.

Geometric origin of magnetic frustration in the µ-Al4Mn giant-unit-cell complex intermetallic.

The structurally ordered µ-Al(4)Mn complex intermetallic phase with 563 atoms in the giant unit cell shows the typical broken-ergodicity phenomena of a magnetically frustrated spin system. The low-field zero-field-cooled and field-cooled magnetic susceptibilities show splitting below the spin freezing temperature T(f) = 2.7 K. The ac susceptibility exhibits a frequency-dependent cusp, associated with a frequency-dependent freezing temperature T(f)(ν). The decay of the thermoremnant magnetization is logarithmically slow in time and shows a dependence on the aging time t(w) and the cooling field H(fc) typical of an ultraslow out-of-equilibrium dynamics of a nonergodic spin system that approaches thermal equilibrium, but can never reach it on the experimentally accessible time scale. The above features classify the µ-Al(4)Mn complex intermettalic among spin glasses. The origin of frustration of magnetic interactions was found to be geometrical due to the distribution of a significant fraction of Mn spins on triangles with antiferromagnetic coupling. The µ-Al(4)Mn phase is a geometrically frustrated spin glass.

The hydrogen dynamics of CsH5(PO4)2 studied by means of nuclear magnetic resonance.

We have investigated the hydrogen dynamics of cesium pentahydrogen diphosphate, CsH(5)(PO(4))(2), by means of nuclear magnetic resonance (NMR) spectroscopy, in order to address the question of why there is no superprotonic phase transition in this compound, in contrast to other structurally similar hydrogen-bonded ionic salts, where a superprotonic transition is frequently found to be present. The analysis of the NMR spectrum and the spin-lattice relaxation rate revealed that the temperature-dependent hydrogen dynamics of CsH(5)(PO(4))(2) involves motional processes (the intra-H-bond jumps and the inter-H-bond jumps at elevated temperatures, as a mechanism of the ionic conductivity) identical to those for the other H-bonded superprotonic salts. The considerably stronger H-bond network in CsH(5)(PO(4))(2) prompts the search for a higher superprotonic transition temperature. However, due to the relatively weak bonding between the {[H(2)PO(4)]}∞ planes in the [100] direction of the CsH(5)(PO(4))(2) structure by means of the ionic bonding via the cesium atoms and the small number of H bonds in that direction (where out of five H bonds in the unit cell, four are directed within the {[H(2)PO(4)]}∞ planes and only one is between the planes), the bonds between the planes become thermally broken and the crystal melts before the H-bond network rearranges via water release into an open structure typical of the superprotonic phase. Were the coupling between the {[H(2)PO(4)]}∞ planes in the CsH(5)(PO(4))(2) somewhat stronger, the superprotonic transition would occur in the same manner as it does in other structurally related hydrogen-bonded ionic salts.

Fine structure in the electronic density of states near the Fermi energy of Al-Ni-Co decagonal quasicrystal from ultrafast time-resolved optical reflectivity.

We measured the temperature and fluence dependence of the time-resolved photoinduced optical reflectivity in a decagonal Al71.9Ni11.1Co17.0 quasicrystal. We find no evidence for the relaxation of a hot thermalized electron gas as observed in metals. Instead, a quick diffusion of the hot nonthermal carriers approximately 40 nm into the bulk is detected, enhanced by the presence of a broad pseudogap. From the relaxation dynamics we find evidence for the suppression of the electronic density of states (DOS) at the Fermi energy with respect to the electronic DOS at approximately 13 meV away from the Fermi energy which is consistent with recent theoretical calculations.

Surface-spin magnetism of antiferromagnetic NiO in nanoparticle and bulk morphology.

The surface-spin magnetism of the antiferromagnetic (AFM) material NiO in nanoparticle and bulk morphology was investigated by magnetic measurements (temperature-dependent zero-field-cooled (zfc) and field-cooled (fc) dc susceptibility, ac susceptibility and zfc and fc hysteresis loops). We addressed the question of whether the multisublattice ordering of the uncompensated surface spins and the exchange bias (EB) effect are only present in the nanoparticles, originating from their high surface-to-volume ratio or if these surface phenomena are generally present in the AFM materials regardless of their bulky or nanoparticle morphology, but the effect is just too small to be detected experimentally in the bulk due to a very small surface magnetization. Performing experiments on the NiO nanoparticles of different sizes and bulk NiO grains, we show that coercivity enhancement and hysteresis loop shift in the fc experiments, considered to be the key experimental manifestations of multisublattice ordering and the EB effect, are true nanoscale phenomena only present in the nanoparticles and absent in the bulk.

Low temperature charge and orbital textures in La0.875Sr0.125MnO3.

By using nuclear magnetic resonance techniques we show that for T<30 K the La0.875Sr0.125MnO3 compound displays a nonuniform charge distribution, comprised of two interconnected Mn ion subsystems with different spin, orbital, and charge couplings. The NMR results agree very well with the two spin wave stiffness constants observed at small q values in the spin wave dispersion curves [Phys. Rev. B 67, 214430 (2003)]. This picture is probably related to a yet undetermined charge and orbital superstructure occurring in the ferromagnetic insulating state of the La0.875Sr0.125MnO3 compound.

Orbital domain state and finite size scaling in ferromagnetic insulating manganites.

55Mn and 139La NMR measurements on a high quality single crystal of ferromagnetic (FM) La0.80Ca0.20MnO3 demonstrate the formation of localized Mn(3+,4+) states below 70 K, accompanied by a strong cooling-rate dependent increase of certain FM neutron Bragg peaks. (55,139)(1/T(1)) spin-lattice and (139)(1/T(2)) spin-spin relaxation rates are strongly enhanced on approaching this temperature from below, signaling a genuine phase transition at T(tr) approximately 70 K. The disappearance of the FM metallic signal by applying a weak external magnetic field, the different NMR radio-frequency enhancement of the FM metallic and insulating states, and the observed finite size scaling of T(tr) with Ca (hole) doping, as observed in powder La(1-x)CaxMnO3 samples, are suggestive of freezing into an inhomogeneous FM insulating and orbitally ordered state embodying "metallic" hole-rich walls.

Dynamics of the pinned modulation wave in incommensurate bis (4-chlorophenyl) sulfone (BCPS).

We show that both the anomalously huge resonance-frequency dependence of the (35)Cl nuclear quadrupole resonance (NQR) spin-lattice relaxation time in BCPS, reported here for the first time, and its anomalous temperature dependence can be explained by large-scale fluctuations of the pinned modulation wave instead of small-scale fluctuations (phasons and amplitudons). The results were obtained by measuring the laboratory (T(1Q)) and rotating frame (T(1Q,rho)) (35)Cl relaxation times. This is the first time that an effective resonance frequency dependence of the spin-lattice relaxation rate was measured in pure NQR.

Modeling the static fringe field of superconducting magnets.

The resonance frequency-space and the frequency gradient-space relations are evaluated analytically for the static fringe magnetic field of superconducting magnets used in the NMR diffusion measurements. The model takes into account the actual design of the high-homogeneity magnet coil system that consists of the main coil and the cryoshim coils and enables a precise calibration of the on-axis magnetic field gradient and the resonance frequency inside and outside of the superconducting coil.

Ultrasonographic assessment of celiac disease in children: comparison with antiendomysium antibodies and histology.

UNLABELLED: Several attempts have been made to identify accurate screening tests for celiac disease (CD) with the aim to reduce the need for biopsy or obtaining appropriate selection criteria prior to intestinal biopsy. In this context we evaluated the usefulness of screening for endomysial antibodies (EMA) in the diagnosis of CD in children in comparison with CD-related changes detected by ultrasound (US) or biopsy. PATIENTS: We studied 35 children (1-15 years, 22 girls and 13 boys, mean age 8 years) with untreated CD (N = 15), treated CD (N = 10) and controls (N = 10), undergoing small bowel biopsy as a diagnostic procedure. METHODS: US of the small bowel was performed prior to mucosa biopsy using a 4- or 7-MHz transducer of a computed sonography device. The thickness of the intestinal wall and small bowel motility were recorded. Simultaneously, all children had serum routinely sampled for IgA EMA. RESULTS: All controls had histologically normal small bowel mucosa, US showed a small bowel wall thickness of 1 mm with normal motility in 9 children and non-specific wall changes in 1 child. EMA was weakly positive in 1 of these, and negative in all other controls. Of 15 children with untreated CD, severe enteropathy and strongly positive EMA were found in 10 cases; in 5 children moderate enteropathy and positive EMA were detected. Severe US changes were found in all of these children (1.6 mm thickness of the intestinal wall, hyperperistalsis and abundant fluid in the bowel). Mild enteropathy was found in 10 children with treated CD (3 months of a gluten-free diet). EMA was positive in 2 children and weakly positive in 8. Non-specific US changes were found in 6 children. In conclusion, our results indicate that US provides valuable information on small-bowel wall structure and can help in decision making on the necessity of small bowel biopsy. The present study confirms a stronger correlation between EMA and CD than between US and CD.

55Mn NMR investigation of electronic phase separation in La1-xCaxMnO3 for 0.2 < or = x < or = 0.5.

55Mn NMR line shape measurements in La1-xCaxMnO3 for 0.20< or =x< or =0.50 provide experimental evidence about the existence of two distinct regions in the T-x magnetic phase diagram, where the homogeneous ferromagnetic (FM) metallic state is separated into FM metallic and FM insulating regions. These results are in agreement with recent theoretical predictions, which reveal a novel electronic phase separation in two FM states, providing orbital ordering and Jahn-Teller phonons are taken into consideration.

Phonon-assisted spin diffusion in solids

The spin flip-flop transition rate is calculated for the case of spectral spin diffusion within a system of dipolarly coupled spins in a solid where the lattice vibrations are present. Long-wavelength acoustic phonons time-modulate the interspin distance r(ij) and enhance the transition rate via the change of the 1/r(3)(ij) term in the coupling dipolar Hamiltonian. The phonon-assisted spin diffusion rate is calculated by the golden rule in the Debye approximation of the phonon density of states. The coupling of the spins to the phonons introduces temperature dependence into the transition rate, in contrast to the spin diffusion in a rigid lattice, where the rate is temperature-independent. The direct (one-phonon absorption or emission) processes introduce a linear temperature dependence into the rate at temperatures not too close to T = 0. Two-phonon processes introduce a more complicated temperature dependence that again becomes simple analytical for temperatures higher than the Debye temperature, where the rate is proportional to T(2), and in the limit T --> 0, where the rate varies as T(7). Raman processes (one-phonon absorption and another phonon emission) dominate by far the phonon-assisted spin flip-flop transitions. Copyright 2000 Academic Press.