Orofacial cleft management by short-term surgical missions in South America: literature review.

There is a growing demand for surgical care in South America, particularly for patients with congenital orofacial clefts (OFCs). Short-term surgical missions (STSMs) have emerged as a means to deliver surgical expertise and alleviate this demand. The aim of this study was to review the quantity and quality of peer-reviewed reports on OFC repairs performed by STSMs in South America. A literature search was conducted using the PubMed, Embase, Web of Science, and SciELO databases. The search was limited to articles published in English and Spanish. Descriptive statistics were used for the data analysis. The search yielded 65 studies related to OFCs. Eight (12.3%) were selected for full-text review. Only five (7.7%) articles met the inclusion criteria. The diverse study designs and heterogeneous types of data assessment among the selected studies hindered a comparison between them. This review found a sparse number of publications pertaining to OFC missions to South America. The articles that were included demonstrated inconsistencies in reporting patient care data. There is a need for a more efficient, streamlined method of reporting humanitarian missions for OFC repairs in order for healthcare professionals to fulfill research and ethical obligations and offer the best practices in patient-centered care.

Genetic variations of CD36 and low platelet CD36 expression - a risk factor for lipemic plasma donation in Taiwanese apheresis donors.

BACKGROUND: New CD36 mutations are constantly being identified, although no study has specifically targeted a Taiwanese population. CD36 deficiency can result in dyslipid state and slow clearance of chylomicron. This could be linked to more frequent lipemic donations. STUDY DESIGN AND METHODS: We used flow cytometric methods to study the CD36 deficiency in 640 regular volunteer platelet apheresis donors from Taipei blood centre. The coding exons of CD36 gene were sequenced in CD36-deficient individuals, and the allele frequencies of CD36 variants were determined in the larger population by mutation-specific PCR and oligonucleotide hybridization. Visual inspection of lipemic plasma was routinely performed on samples taken before commencement of apheresis. Individuals found to have lipemic plasma are deferred until next donation. We investigated the link between positive lipemic deferral record and low platelet CD36 expression status. RESULTS: We found four donors (0·6%) with type I CD36 deficiency (both platelets and monocytes CD36(null) ) and six (1·0%) with type II CD36 deficiency (PLT: CD36(null) , monocyte: CD36(low) ). Six CD36 genetic variants were identified, two of them were novel, all but one are found exclusively in CD36(null) and CD36(low) expressors. Subjects with CD36 genetic variants also displayed deficient or reduced CD36 on monocytes. Donors with null or low PLT CD36 expression were more likely to have a lipemic deferral record than control subjects with normal PLT CD36 expression (X(2) = 27·36, odds ratio = 2·6, 95% conference interval: 1·8-3·8, P < 0·0001). CONCLUSION: Through this study, we established a donor registry to supply CD36-negative platelets for patients in need.

Epidemiology of pediatric facial trauma in Chile: a retrospective study of 7,617 cases in 3 years.

OBJECTIVES: To describe the epidemiology of facial trauma injuries in a group of Chilean children aged 15 years or less. STUDY DESIGN: Retrospective study of case series. Between 2006 and 2009, clinical records of 293,090 patients were reviewed. Data of patients with trauma injuries to the face were collected and evaluated for: age, sex, day and month of hospital admission, cause of injury, anatomical location, type of injury and presence of associated injuries. RESULTS: A total of 7,617 patients with 8,944 injuries were found. Boy to girl ratio was 1,7:1. Preschool age children were most frequently affected. Main cause of injury were falls, soft tissue injuries the most common type of injury. Associated injuries occurred in 11% of cases. CONCLUSIONS: Facial trauma presents a significant frequency in the group of Chilean children studied. Preeschool age boys were prone to present facial trauma of mild severity associated to falls.

Effects of Lactobacillus kefiranofaciens M1 isolated from kefir grains on enterohemorrhagic Escherichia coli infection using mouse and intestinal cell models.

A potential probiotic strain, Lactobacillus kefiranofaciens M1, was previously isolated from kefir grains, which are used to manufacture the traditional fermented drink kefir. The aim of this study was to investigate the effects of Lb. kefiranofaciens M1 on enterohemorrhagic Escherichia coli (EHEC) infection, using mice and intestinal cell models. BALB/c mice were daily administrated with either phosphate buffered saline or Lb. kefiranofaciens M1 at 2×10(8) cfu/mouse per day intragastrically for 7 d. Intragastric challenges with EHEC (2×10(9) cfu/mouse) were conducted on d 0, 4, and 7 after treatment. Administration of Lb. kefiranofaciens M1 was able to prevent EHEC infection-induced symptoms, intestinal damage, renal damage, bacterial translocation, and Shiga toxin penetration. Furthermore, the mucosal EHEC-specific IgA responses were increased after Lb. kefiranofaciens M1 administration in the EHEC-infected mouse system. Additionally, in vitro, Lb. kefiranofaciens M1 was shown to have a protective effect on Caco-2 intestinal epithelial cells and Caco-2 intestinal epithelial cell monolayers; the bacteria limited EHEC-induced cell death and reduced the loss of epithelial integrity. These findings support the potential of Lb. kefiranofaciens M1 treatment as an approach to preventing EHEC infection and its effects.

Determination of the Co valence in bilayer hydrated superconducting NaxCoO2 · yH2O by soft x-ray absorption spectroscopy.

We addressed the so-far unresolved issue concerning the Co valence in the superconducting bilayer hydrated Na(x)CoO(2) · yH(2)O (x∼0.35, y∼1.3) using soft x-ray absorption spectroscopy at the Co-L(2,3) and O-K edges. We find that the valence state of the Co lies in a narrow range from +3.3 to +3.4 for all studied Na(x)CoO(2) · yH(2)O samples and their deuterated analogue with T(c)'s ranging from 3.8 to 4.7 K. These valence values are far from the often claimed +3.7, the number based on the Na content only. We propose to modify the phase diagram accordingly, where the basic electronic structure of the superconducting phase is very close to that of the Na(0.7)CoO(2) system, suggesting that the presence of in-plane spin fluctuations could play an important role for the superconductivity.

Spin blockade, orbital occupation, and charge ordering in La1.5Sr0.5CoO4.

Using Co-L2,3 and O-K x-ray absorption spectroscopy, we reveal that the charge ordering in La1.5Sr0.5CoO4 involves high spin (S=3/2) Co2+ and low spin (S=0) Co3+ ions. This provides evidence for the spin-blockade phenomenon as a source for the extremely insulating nature of the La2-xSrxCoO4 series. The associated e{g}{2} and e{g}{0} orbital occupation accounts for the large contrast in the Co-O bond lengths and, in turn, the high charge ordering temperature. Yet, the low magnetic ordering temperature is naturally explained by the presence of the nonmagnetic (S=0) Co3+ ions. From the identification of the bands we infer that La1.5Sr0.5CoO4 is a narrow band material.

The impact and recovery of asteroid 2008 TC(3).

In the absence of a firm link between individual meteorites and their asteroidal parent bodies, asteroids are typically characterized only by their light reflection properties, and grouped accordingly into classes. On 6 October 2008, a small asteroid was discovered with a flat reflectance spectrum in the 554-995 nm wavelength range, and designated 2008 TC(3) (refs 4-6). It subsequently hit the Earth. Because it exploded at 37 km altitude, no macroscopic fragments were expected to survive. Here we report that a dedicated search along the approach trajectory recovered 47 meteorites, fragments of a single body named Almahata Sitta, with a total mass of 3.95 kg. Analysis of one of these meteorites shows it to be an achondrite, a polymict ureilite, anomalous in its class: ultra-fine-grained and porous, with large carbonaceous grains. The combined asteroid and meteorite reflectance spectra identify the asteroid as F class, now firmly linked to dark carbon-rich anomalous ureilites, a material so fragile it was not previously represented in meteorite collections.

Determining the crystal-field ground state in rare earth heavy fermion materials using soft-x-ray absorption spectroscopy.

We infer that soft-x-ray absorption spectroscopy is a versatile method for the determination of the crystal-field ground state symmetry of rare earth heavy fermion systems, complementing neutron scattering. Using realistic and universal parameters, we provide a theoretical mapping between the polarization dependence of Ce M(4,5) spectra and the charge distribution of the Ce 4f states. The experimental resolution can be orders of magnitude larger than the 4f crystal-field splitting itself. To demonstrate the experimental feasibility of the method, we investigated CePd2Si2, thereby settling an existing disagreement about its crystal-field ground state.

Magnetizing oxides by substituting nitrogen for oxygen.

We describe a possible pathway to new magnetic materials with no conventional magnetic elements present. The substitution of nitrogen for oxygen in simple nonmagnetic oxides leads to holes in N 2p states which form local magnetic moments. Because of the very large Hund's rule coupling of Nitrogen and O 2p electrons and the rather extended spatial extent of the wave functions these materials are predicted to be ferromagnetic metals or small band gap insulators. Experimental studies support the theoretical calculations with regard to the basic electronic structure and the formation of local magnetic moments. It remains to be seen if these materials are magnetically ordered and, if so, below what temperature.

Spin state transition in LaCoO3 studied using soft x-ray absorption spectroscopy and magnetic circular dichroism.

Using soft x-ray absorption spectroscopy and magnetic circular dichroism at the Co-L(2,3) edge, we reveal that the spin state transition in LaCoO3 can be well described by a low-spin ground state and a triply degenerate high-spin first excited state. From the temperature dependence of the spectral line shapes, we find that LaCoO3 at finite temperatures is an inhomogeneous mixed-spin state system. It is crucial that the magnetic circular dichroism signal in the paramagnetic state carries a large orbital momentum. This directly shows that the currently accepted low- or intermediate-spin picture is at variance. Parameters derived from these spectroscopies fully explain existing magnetic susceptibility, electron spin resonance, and inelastic neutron data.

Transfer of spectral weight and symmetry across the metal-insulator transition in VO(2).

We present a detailed study of the valence and conduction bands of VO2 across the metal-insulator transition using bulk-sensitive photoelectron and O K x-ray absorption spectroscopies. We observe a giant transfer of spectral weight with distinct features that require an explanation which goes beyond the Peierls transition model as well as the standard single-band Hubbard model. Analysis of the symmetry and energies of the bands reveals the decisive role of the V 3d orbital degrees of freedom. Comparison to recent realistic many body calculations shows that much of the k dependence of the self-energy correction can be cast within a dimer model.

Orbitally driven spin-singlet dimerization in S=1 La4Ru2O10.

Using x-ray absorption spectroscopy at the Ru-L2,3 edge we reveal that the Ru4+ ions remain in the S=1 spin state across the rare 4d-orbital ordering transition and spin-gap formation. We find using local spin density approximation + Hubbard U band structure calculations that the crystal fields in the low-temperature phase are not strong enough to stabilize the S=0 state. Instead, we identify a distinct orbital ordering with a significant anisotropy of the antiferromagnetic exchange couplings. We conclude that La4Ru2O10 appears to be a novel material in which the orbital physics drives the formation of spin-singlet dimers in a quasi-two-dimensional S=1 system.

Controlling orbital moment and spin orientation in CoO layers by strain.

We have observed that CoO films grown on different substrates show dramatic differences in their magnetic properties. Using polarization dependent x-ray absorption spectroscopy at the Co L2,3 edges, we revealed that the magnitude and orientation of the magnetic moments strongly depend on the strain in the films induced by the substrate. We presented a quantitative model to explain how strain together with the spin-orbit interaction determine the 3d orbital occupation, the magnetic anisotropy, as well as the spin and orbital contributions to the magnetic moments. Control over the sign and direction of the strain may, therefore, open new opportunities for applications in the field of exchange bias in multilayered magnetic films.

Orbital-assisted metal-insulator transition in VO2.

We found direct experimental evidence for an orbital switching in the V 3d states across the metal-insulator transition in VO2. We have used soft-x-ray absorption spectroscopy at the V L2,3 edges as a sensitive local probe and have determined quantitatively the orbital polarizations. These results strongly suggest that, in going from the metallic to the insulating state, the orbital occupation changes in a manner that charge fluctuations and effective bandwidths are reduced, that the system becomes more one dimensional and more susceptible to a Peierls-like transition, and that the required massive orbital switching can only be made if the system is close to a Mott insulating regime.

Determination of the orbital moment and crystal-field splitting in LaTiO3.

Utilizing a sum rule in a spin-resolved photoelectron spectroscopic experiment with circularly polarized light, we show that the orbital moment in LaTiO3 is strongly reduced from its ionic value, both below and above the Ne el temperature. Using Ti L2,3 x-ray absorption spectroscopy as a local probe, we found that the crystal-field splitting in the t2g subshell is about 0.12-0.30 eV. This large splitting does not facilitate the formation of an orbital liquid.

Different look at the spin state of Co(3+) ions in a CoO(5) pyramidal coordination.

Using soft-x-ray absorption spectroscopy at the Co L(2,3) and O K edges, we demonstrate that the Co3+ ions with the CoO5 pyramidal coordination in the layered Sr2CoO3Cl compound are unambiguously in the high spin state. Our result questions the reliability of the spin state assignments made so far for the recently synthesized layered cobalt perovskites and calls for a reexamination of the modeling for the complex and fascinating properties of these new materials.

Magnetic dichroism and spin structure of antiferromagnetic NiO(001) films.

We find that Ni L2 edge x-ray magnetic linear dichroism is fully reversed for NiO(001) films on materials with reversed lattice mismatch. We relate this phenomenon to a preferential stabilization of magnetic S domains with main spin component either in or out of the plane, via dipolar interactions. This suggests a way to selectively control spin structures in 3d systems with small spin-orbit coupling.

Estancia hospitalaria en cirugía de fisura labio maxilo palatina / Hospitalary stay in the surgery of the maxillo-palatal-lip fissure

La Unidad de Fisurados del Servicio de Cirugía Infantil del Hospital Dr. Félix Bulnes Cerda de Santiago de Chile ha adoptado en los casos de reconstrucción primaria de fisuras labio máxilo palatinas (FL/M/P), el sistema de ingreso el mismo día operatorio con 24 horas de observación post-quirúrgica. Se revisó las historias clínicas de 146 pacientes operados de fisura labio/máxilo/palatina entre los años 1997 y 2002. Después de excluir los pacientes sindrómicos y de reconstrucción secundaria quedaron 50 casos de reconstrucción primaria que fueron analizados para este estudio. Se estudió la edad del paciente en el momento de la operación, tipo de cirugía realizada, duración de la intervención, tiempo de estancia postoperatoria y morbilidad a corto plazo. La estancia hospitalaria promedio fue de 26,4 horas (1,10 días), con un rango de 24-72 horas. El 90,47 por ciento (76 intervenciones) tuvieron un período postoperatorio hospitalario de 24 horas, el 8,33 por ciento (7 intervenciones) de 48 horas y el 1,19 por ciento (1 intervención) de 72 horas. La tasa de complicaciones fue de 10,18 por ciento, la cual incluyó 4 dehiscencias totales y 3 dehiscencias parciales velopalatinas y 4 dehiscencias parciales en paladar duro. No se requirieron transfusiones sanguíneas ni se produjeron infecciones en el postoperatorio. Los pacientes no debieron ser reingresados por sangrado, compromiso respiratorio o inadecuada alimentación por vía bucal. Los autores sostienen que un postoperatorio de 24 horas permite optimizar los recursos existentes en las instituciones de salud sin olvidar el bienestar y seguridad del paciente. La decisión del alta hospitalaria debe permanecer a criterio del cirujano tratante (AU)

Ferromagnetism induced by clustered Co in Co-doped anatase TiO2 thin films.

We investigated ferromagnetism of a newly discovered ferromagnetic semiconductor Co-doped anatase TiO2 thin film, using the magnetic circular dichroism (MCD) at the Co L(2,3) absorption edges. The magnetic moment was observed to be approximately 0.1 micro(B)/Co in the measurements, but the MCD spectral line shape is nearly identical to that of Co metal, showing that the ferromagnetism is induced by a small amount of clustered Co. With thermal treatments at approximately 400 degrees C, the MCD signal increases, and the moment reaches up to approximately 1.55 micro(B)/Co, which is approximately 90% of the moment in Co metal. In the latter case, the cluster size was observed to be 20-60 nm.