Disruptive Dizziness Among Post-9/11 Veterans With Deployment-Related Traumatic Brain Injury.

OBJECTIVE: To identify disruption due to dizziness symptoms following deployment-related traumatic brain injury (TBI) and factors associated with receiving diagnoses for these symptoms. SETTING: Administrative medical record data from the Department of Veterans Affairs (VA). PARTICIPANTS: Post-9/11 veterans with at least 3 years of VA care who reported at least occasional disruption due to dizziness symptoms on the comprehensive TBI evaluation. DESIGN: A cross-sectional, retrospective, observational study. MAIN MEASURES: International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes of dizziness, vestibular dysfunction, and other postconcussive conditions; neurobehavioral Symptom Inventory. RESULTS: Increased access to or utilization of specialty care at the VA was significant predictors of dizziness and/or vestibular dysfunction diagnoses in the fully adjusted model. Veterans who identified as Black non-Hispanic and those with substance use disorder diagnoses or care were substantially less likely to receive dizziness and vestibular dysfunction diagnoses. CONCLUSIONS: Access to specialty care was the single best predictor of dizziness and vestibular dysfunction diagnoses, underscoring the importance of facilitating referrals to and utilization of specialized, comprehensive clinical facilities or experts for veterans who report disruptive dizziness following deployment-related TBI. There is a clear need for an evidence-based pathway to address disruptive symptoms of dizziness, given the substantial variation in audiovestibular tests utilized by US providers by region and clinical specialty. Further, the dearth of diagnoses among Black veterans and those in more rural areas underscores the potential for enhanced cultural competency among providers, telemedicine, and patient education to bridge existing gaps in the care of dizziness.

Monitoring spin-crossover phenomena via Re(I) luminescence in hybrid Fe(II) silica coated nanoparticles.

Bare (1) and silica coated (1@SiO2) spin crossover (SCO) nanoparticles based on the polymer {[Fe(NH2Trz)3](BF4)2}n have been prepared following a water-in-oil synthetic procedure. For 1, the critical temperatures of the spin transition are TC↓ = 214.6 K and TC↑ = 220.9 K. For 1@SiO2, the abruptness of the transition is enhanced and the critical temperatures are centred at room temperature (TC↓ = 292.1 K and TC↑ = 296.3 K). An inert Re(I) complex of formula [Re(phen)(CO)3(PETES)](PF6) (phen = 1, 10-phenanthroline; PETES = 2(4-pyridylethyl)triethoxysilane) (Re) was also synthesized yielding intense green emission centred at λem = 560 nm. The grafting of this complex on the silica shell of 1@SiO2 led to a bifunctional SCO-luminescence composite (1@SiO2/Re) whose luminescence properties were tuned by the spin state switching. Temperature-variable photophysical studies showed that luminescence and spin transition were synchronized through a radiative (trivial) energy transfer mechanism between the Re(I) and the Fe(II)-LS (LS, Low Spin) centres.

Epilepsy quality performance in a national sample of neurologists and primary care providers: Characterizing trends in acute and chronic care management.

INTRODUCTION: Epilepsy-specific quality indicators and performance measures have been published and revised multiple times. The application of epilepsy-specific quality measures has been demonstrated in a few healthcare systems. However, there is no information to date on changes in epilepsy performance measures over time, and across settings, in a national sample. The Department of Veterans Affairs (VA) healthcare system provides an opportunity to study the changes in epilepsy-specific performance over time, in acute versus chronic epilepsy care, as well as in primary versus specialty care. METHODS: Chart extractions of newly diagnosed epilepsy and chronic care of Veterans with epilepsy within the VA system were performed. Veterans with ICD-9-CM diagnosis 345.XX and 780.39 from 2007-2014 were identified. Epilepsy-specific performance measures based on the Quality Indicators in Epilepsy Treatment (QUIET) VA measurement were ascertained for each Veteran with epilepsy. Difference in care across time (2009, 2012, and 2014), source of epilepsy care (primary care only, neurology only, and shared care between neurology and primary care) was analyzed. Differences in proportion of care measures across variables were compared using chi-square statistics. RESULTS: Chart reviews of 2386 Veterans with epilepsy included 297 women (11.2%), 281 (10.5%) receiving acute care and 2105 (89.5%) receiving chronic care. Across all years 203 (72.5%) had electroencephalograph ordered/performed, 225 (80.4%) had neuroimaging ordered/performed, 106 (37.9%) were instructed about driving precautions, 71 (25.4%) were educated about safety and injury prevention, and 251 (89.6%) had anti-seizure medication monotherapy initiated. The proportion of people with new-onset seizures educated about diagnosis and type of seizure increased over time 30 (34.9%) in 2008, 42 (43.8%) in 2012, and 52 (53.1%). Of the 2105 Veterans receiving chronic care 864 (41.1%) encounters documented compliance of anti-seizure medication, 361 (17.15%) encounters addressed driving restrictions, 1345 (63.9%) encounters documented general education and counseling, 250 (11.9%) of encounters documented safety and injury prevention, 488 (23.2%) of encounters documented medication side effects, and 463 (22.0%) of encounters documented discussion of treatment options. With chronic epilepsy care, documentation of quality measures did not change with time. Veterans who were co-managed by primary care and neurology had a higher proportion of driving instruction and safety instructions compared to neurology or primary care alone. DISCUSSION: In general, the epilepsy performance measures were high (>70% of new-onset epilepsy) for documentation diagnostic procedures (such as EEG and neuroimaging) and low across key educational and counseling measures (<50%). Despite the emphasis on the importance of psychosocial education and holistic management in the academic literature, through advocacy work, and during professional meetings, there was not a significant improvement in education and counseling over time. Some aspects of psychosocial education were performed better among primary care providers compared to neurologists. However, more attention and work need to be dedicated on implementing and documenting education and counseling people with epilepsy in the clinical setting.

Effect of Ligand Substitution around the Dy(III) on the SMM Properties of Dual-Luminescent Zn-Dy and Zn-Dy-Zn Complexes with Large Anisotropy Energy Barriers: A Combined Theoretical and Experimental Magnetostructural Study.

The new dinuclear Zn(II)-Dy(III) and trinuclear Zn(II)-Dy(III)-Zn(II) complexes of formula [(LZnBrDy(ovan) (NO3)(H2O)](H2O)·0.5(MeOH) (1) and [(L(1)ZnBr)2Dy(MeOH)2](ClO4) (3) (L and L(1) are the dideprotonated forms of the N,N'-2,2-dimethylpropylenedi(3-methoxysalicylideneiminato and 2-{(E)-[(3-{[(2E,3E)-3-(hydroxyimino)butan-2-ylidene ]amino}-2,2-dimethylpropyl)imino]methyl}-6-methoxyphenol Schiff base compartmental ligands, respectively) have been prepared and magnetostructurally characterized. The X-ray structure of 1 indicates that the Dy(III) ion exhibits a DyO9 coordination sphere, which is made from four O atoms coming from the compartmental ligand (two methoxy terminal groups and two phenoxido bridging groups connecting Zn(II) and Dy(III) ions), other four atoms belonging to the chelating nitrato and ovanillin ligands, and the last one coming to the coordinated water molecule. The structure of 3 shows the central Dy(III) ion surrounded by two L(1)Zn units, so that the Dy(III) and Zn(II) ions are linked by phenoxido/oximato bridging groups. The Dy ion is eight-coordinated by the six O atoms afforded by two L(1) ligands and two O atoms coming from two methanol molecules. Alternating current (AC) dynamic magnetic measurements of 1, 3, and the previously reported dinuclear [LZnClDy(thd)2] (2) complex (where thd = 2,2,6,6-tetramethyl-3,5-heptanedionato ligand) indicate single molecule magnet (SMM) behavior for all these complexes with large thermal energy barriers for the reversal of the magnetization and butterfly-shaped hysteresis loops at 2 K. Ab initio calculations on 1-3 show a pure Ising ground state for all of them, which induces almost completely suppressed quantum tunnelling magnetization (QTM), and thermally assisted quantum tunnelling magnetization (TA-QTM) relaxations via the first excited Kramers doublet, leading to large energy barriers, thus supporting the observation of SMM behavior. The comparison between the experimental and theoretical magnetostructural data for 1-3 has allowed us to draw some conclusions about the influence of ligand substitution around the Dy(III) on the SMM properties. Finally, these SMMs exhibit metal- and ligand-centered dual emissions in the visible region, and, therefore, they can be considered as magnetoluminescent bifunctional molecular materials.

Decanuclear Ln10 Wheels and Vertex-Shared Spirocyclic Ln5 Cores: Synthesis, Structure, SMM Behavior, and MCE Properties.

The reaction of a Schiff base ligand (LH3) with lanthanide salts, pivalic acid and triethylamine in 1:1:1:3 and 4:5:8:20 stoichiometric ratios results in the formation of decanuclear Ln10 (Ln = Dy (1), Tb (2), and Gd (3)) and pentanuclear Ln5 complexes (Ln = Gd (4), Tb (5), and Dy (6)), respectively. The formation of Ln10 and Ln5 complexes are fully governed by the stoichiometry of the reagents used. Detailed magnetic studies on these complexes (1-6) have been carried out. Complex 1 shows a SMM behavior with an effective energy barrier for the reversal of the magnetization (Ueff) = 16.12(8) K and relaxation time (τo) = 3.3×10(-5) s under 4000 Oe direct current (dc) field. Complex 6 shows the frequency dependent maxima in the out-of-phase signal under zero dc field, without achieving maxima above 2 K. Complexes 3 and 4 show a large magnetocaloric effect with the following characteristic values: -ΔSm = 26.6 J kg(-1) K(-1) at T = 2.2 K for 3 and -ΔSm = 27.1 J kg(-1) K(-1) at T = 2.4 K for 4, both for an applied field change of 7 T.

Analysis of the Role of Peripheral Ligands Coordinated to Zn(II) in Enhancing the Energy Barrier in Luminescent Linear Trinuclear Zn-Dy-Zn Single-Molecule Magnets.

Three new Dy complexes have been prepared according to a complex-as-ligand strategy. Structural determinations indicate that the central Dy ion is surrounded by two LZn units (L(2-) is the di-deprotonated form of the N2 O2 compartmental N,N'-2,2-dimethylpropylenedi(3-methoxysalicylideneiminato) Schiff base. The Dy ions are nonacoordinate to eight oxygen atoms from the two L ligands and to a water molecule. The Zn ions are pentacoordinate in all cases, linked to the N2 O2 atoms from L, and the apical position of the Zn coordination sphere is occupied by a water molecule or bromide or chloride ions. These resulting complexes, formulated (LZnX)-Dy-(LZnX), are tricationic with X=H2 O and monocationic with X=Br or Cl. They behave as field-free single-molecule magnets (SMMs) with effective energy barriers (Ueff ) for the reversal of the magnetization of 96.9(6) K with τ0 =2.4×10(-7)  s, 146.8(5) K with τ0 =9.2×10(-8)  s, and 146.1(10) K with τ0 =9.9×10(-8)  s for compounds with ZnOH2 , ZnBr, and ZnCl motifs, respectively. The Cole-Cole plots exhibit semicircular shapes with α parameters in the range of 0.19 to 0.29, which suggests multiple relaxation processes. Under a dc applied magnetic field of 1000 Oe, the quantum tunneling of magnetization (QTM) is partly or fully suppressed and the energy barriers increase to Ueff =128.6(5) K and τ0 =1.8×10(-8)  s for 1, Ueff =214.7 K and τ0 =9.8×10(-9)  s for 2, and Ueff =202.4 K and τ0 =1.5×10(-8)  s for 3. The two pairs of largely negatively charged phenoxido oxygen atoms with short DyO bonds are positioned at opposite sides of the Dy(3+) ion, which thus creates a strong crystal field that stabilizes the axial MJ =±15/2 doublet as the ground Kramers doublet. Although the compound with the ZnOH2 motifs possesses the larger negative charges on the phenolate oxygen atoms, as confirmed by using DFT calculations, it exhibits the larger distortions of the DyO9 coordination polyhedron from ideal geometries and a smaller Ueff value. Ab initio calculations support the easy-axis anisotropy of the ground Kramers doublet and predict zero-field SMM behavior through Orbach and TA-QTM relaxations via the first excited Kramers doublet, which leads to large energy barriers. In accordance with the experimental results, ab initio calculations have also shown that, compared with water, the peripheral halide ligands coordinated to the Zn(2+) ions increase the barrier height when the distortions of the DyO9 have a negative effect. All the complexes exhibit metal-centered luminescence after excitation into the UV π-π* absorption band of ligand L(2-) at λ=335 nm, which results in the appearance of the characteristic Dy(III) ((4) F9/2 →(6) HJ/2 ; J=15/2, 13/2) emission bands in the visible region.

Amending the anisotropy barrier and luminescence behavior of heterometallic trinuclear linear [M(II) -Ln(III) -M(II) ] (Ln(III) =Gd, Tb, Dy; M(II) =Mg/Zn) complexes by change from divalent paramagnetic to diamagnetic metal ions.

The sequential reaction of a multisite coordinating compartmental ligand [2-(2-hydroxy-3-(hydroxymethyl)-5-methylbenzylideneamino)-2-methylpropane-1,3-diol] (LH4 ) with appropriate lanthanide salts followed by the addition of [Mg(NO3 )2 ]⋅6 H2 O or [Zn(NO3 )2 ]⋅6 H2 O in a 4:1:2 stoichiometric ratio in the presence of triethylamine affords a series of isostructural heterometallic trinuclear complexes containing [Mg2 Ln](3+) (Ln=Dy, Gd, and Tb) and [Zn2 Ln](3+) (Ln=Dy, Gd, and Tb) cores. The formation of these complexes is demonstrated by X-ray crystallography as well as ESI-MS spectra. All complexes are isostructural possessing a linear trimetallic core with a central lanthanide ion. The comprehensive studies discussed involve the synthesis, structure, magnetism, and photophysical properties on this family of trinuclear [Mg2 Ln](3+) and [Zn2 Ln](3+) heterometallic complexes. [Mg2 Dy](3+) and [Zn2 Dy](3+) show slow relaxation of the magnetization below 12 K under zero applied direct current (dc) field, but without reaching a neat maximum, which is due to the overlapping with a faster quantum tunneling relaxation mediated through dipole-dipole and hyperfine interactions. Under a small applied dc field of 1000 Oe, the quantum tunneling is almost suppressed and temperature and frequency dependent peaks are observed, thus confirming the single-molecule magnet behavior of complexes [Mg2 Dy](3+) and [Zn2 Dy](3+) .

Single-molecule magnet behavior and magnetocaloric effect in ferromagnetically coupled Ln(III)-Ni(II)-Ni(II)-Ln(III) (Ln(III) = Dy(III) and Gd(III)) linear complexes.

New types of linear tetranuclear Ln(III)-Ni(II)-Ni(II)-Ln(III) (Ln(III) = Dy (1), Gd (2)) complexes have been prepared using the multidentate ligand N,N'-bis(3-methoxysalicylidene)-1,3-diaminobenzene, which has two sets of NO and OO' coordination pockets that are able to selectively accommodate Ni(II) and Ln(III) ions, respectively. The X-ray structure analysis reveals that the Ni(II) ions are bridged by phenylenediimine groups forming a 12-membered metallacycle in the central body of the complex, whereas the Ln(III) ions are located at both sides of the metallacycle and linked to the Ni(II) ions by diphenoxo bridging groups. Phenylenediimine and diphenoxo bridging groups transmit ferromagnetic exchange interactions between the two Ni(II) ions and between the Ni(II) and the Ln(III) ions, respectively. Complex 1 shows slow relaxation of the magnetization at zero field and a thermal energy barrier Ueff = 7.4 K with HDC = 1000 Oe, whereas complex 2 exhibits an S = 9 ground state and significant magnetocaloric effect (-ΔSm = 18.5 J kg(-1) K(-1) at T = 3 K and ΔB = 5 T).

Enantioselective synthesis of α-heteroarylpyrrolidines by copper-catalyzed 1,3-dipolar cycloaddition of α-silylimines.

α-Heteroarylpyrrolidines have been efficiently prepared via 1,3-dipolar cycloaddition between silylimines and activated olefins. In the presence of Cu(CH3CN)4PF6/Walphos as catalytic system, high levels of enantioselectivity (up to ≥99% ee) and diastereoselectivity were achieved (major formation of C-2/C-4 trans-substituted pyrrolidines). The reaction is compatible with a broad variety of dipolarophiles including maleimides, maleates, fumarates, nitroalkenes, and vinylsulfones. The resulting cycloadducts can be transformed into bioactive pyrrolidine derivatives.

Bifunctional Zn(II)Ln(III) dinuclear complexes combining field induced SMM behavior and luminescence: enhanced NIR lanthanide emission by 9-anthracene carboxylate bridging ligands.

There were new dinuclear Zn(II)-Ln(III) complexes of general formulas [Zn(µ-L)(µ-OAc)Ln(NO3)2] (Ln(III) = Tb (1), Dy (2), Er (3), and Yb (4)), [Zn(µ-L)(µ-NO3)Er(NO3)2] (5), [Zn(H2O)(µ-L)Nd(NO3)3]·2CH3OH (6), [Zn(µ-L)(µ-9-An)Ln(NO3)2]·2CH3CN (Ln(III) = Tb (7), Dy (8), Er (9), Yb(10)), [Zn(µ-L)(µ-9-An)Yb(9-An)(NO3)3]·3CH3CN (11), [Zn(µ-L)(µ-9-An)Nd(9-An)(NO3)3]·2CH3CN·3H2O (12), and [Zn(µ-L)(µ-9-An)Nd(CH3OH)2(NO3)]ClO4·2CH3OH (13) prepared from the reaction of the compartmental ligand N,N',N″-trimethyl-N,N″-bis(2-hydroxy-3-methoxy-5-methylbenzyl)diethylenetriamine (H2L), with ZnX2·nH2O (X = NO3(-) or OAc(-)) salts, Ln(NO3)3·nH2O, and, in some instances, 9-anthracenecarboxylate anion (9-An). In all these complexes, the Zn(II) ions invariably occupy the internal N3O2 site whereas the Ln(III) ions show preference for the O4 external site, giving rise to a Zn(µ-diphenoxo)Ln bridging fragment. Depending on the Zn(II) salt and solvent used in the reaction, a third bridge can connect the Zn(II) and Ln(III) metal ions, giving rise to triple-bridged diphenoxoacetate in complexes 1-4, diphenoxonitrate in complex 5, and diphenoxo(9-anthracenecarboxylate) in complexes 8-13. Dy(III) and Er(III) complexes 2, 8 and 3, 5, respectively, exhibit field induced single molecule magnet (SMM) behavior, with Ueff values ranging from 11.7 (3) to 41(2) K. Additionally, the solid-state photophysical properties of these complexes are presented showing that ligand L(2-) is able to sensitize Tb(III)- and Dy(III)-based luminescence in the visible region through an energy transfer process (antenna effect). The efficiency of this process is much lower when NIR emitters such as Er(III), Nd(III), and Yb(III) are considered. When the luminophore 9-anthracene carboxylate is incorporated into these complexes, the NIR luminescence is enhanced which proves the efficiency of this bridging ligand to act as antenna group. Complexes 2, 3, 5, and 8 can be considered as dual materials as they combine SMM behavior and luminescent properties.

Dilution-triggered SMM behavior under zero field in a luminescent Zn2Dy2 tetranuclear complex incorporating carbonato-bridging ligands derived from atmospheric CO2 fixation.

The synthesis, structure, magnetic, and luminescence properties of the Zn2Dy2 tetranuclear complex of formula {(µ3-CO3)2[Zn(µ-L)Dy(NO3)]2}·4CH3OH (1), where H2L is the compartmental ligand N,N',N″-trimethyl-N,N″-bis(2-hydroxy-3-methoxy-5-methylbenzyl)diethylenetriamine, are reported. The carbonate anions that bridge two Zn(µ-L)Dy units come from the atmospheric CO2 fixation in a basic medium. Fast quantum tunneling relaxation of the magnetization (QTM) is very effective in this compound, so that single-molecule magnet (SMM) behavior is only observed in the presence of an applied dc field of 1000 Oe, which is able to partly suppress the QTM relaxation process. At variance, a 1:10 Dy:Y magnetic diluted sample, namely, 1', exhibits SMM behavior at zero applied direct-current (dc) field with about 3 times higher thermal energy barrier than that in 1 (U(eff) = 68 K), thus demonstrating the important role of intermolecular dipolar interactions in favoring the fast QTM relaxation process. When a dc field of 1000 Oe is applied to 1', the QTM is almost fully suppressed, the reversal of the magnetization slightly slows, and U(eff) increases to 78 K. The dilution results combined with micro-SQUID magnetization measurements clearly indicate that the SMM behavior comes from single-ion relaxation of the Dy(3+) ions. Analysis of the relaxation data points out that a Raman relaxation process could significantly affect the Orbach relaxation process, reducing the thermal energy barrier U(eff) for slow relaxation of the magnetization.

Photographing the synergy between magnetic and colour properties in spin crossover material [Fe(NH2trz)3](BF4)2: a temperature sensor perspective.

We introduce the first method for imaging colour changes related to a spin crossover phenomenon induced by thermal variation which can be determined with the naked eye or with a photographic digital camera in a solid phase sensor.

Au-catalyzed asymmetric formal [3 + 2] cycloaddition of isocyanoacetates with maleimides.

An efficient protocol for the Au(I)-catalyzed asymmetric formal [3 + 2] cycloaddition of isocyanoacetates with phenylmaleimide has been developed. In the presence of cationic Au(I)/DTBM-segphos complex, excellent diastereoselectivity and high levels of enantioselectivity (up to 97% ee) have been attained with a variety of α-substituted isocyanoacetates. The synthetic potential of the resulting enantioenriched 1-pyrrolines has been demonstrated by the preparation of highly substituted pyrrolidines bearing a quaternary stereocenter.

Aptitud física de trabajadores que realizan trabajo manual o mecanizado en faenas forestales chilenas / Physical fitness of workers carrying out manual and mechanized forestry work in Chile

El objetivo del presente estudio fue verificar si existen diferencias en la aptitud física de trabajadores forestales que desempeñan actividades dinámicas de tipo manual y trabajadores forestales que realizan actividades mecanizadas. La población estudiada correspondió a 917 varones entre 20 y 49 años de edad, evaluados entre los años 2001 y 2006. Los índices fisiológicos considerados para la evaluación de la condición física, fueron porcentaje corporal de masa grasa y capacidad aeróbica (VO2 máx) expresada en l O2 min-1 y en ml O2 min-1 kg-1. Los resultados mostraron que existen diferencias estadísticamente significativas de medias, respecto al peso corporal, el porcentaje de masa grasa y la capacidad aeróbica, variables que presentaron mejores resultados en los trabajadores que desempeñaban actividades manuales. Se concluye que estas diferencias se debieron principalmente al menor gasto de energía que demanda el trabajo mecanizado, puesto que los trabajadores estudiados, tenían similares características en edad y estatura, convivían juntos en campamentos forestales, donde consumían los mismos alimentos y mantenían hábitos similares de recreación, por lo que sus estilos de vida se diferenciaban básicamente en la demanda energética del trabajo realizado.

The aim of the present study was to determine if there are differences in the physical fitness of Chilean workers carrying out manual versus mechanized work in forestry. The study was carried out on a sample of 917 male workers, 20 to 49 years of age, and evaluated in the Ergonomics Unit of the University of Concepcion between 2001 and 2006. Aerobic capacity (VO2 max), expressed as l O2 min-1 and in ml O2 min-1 kg-1 , as well as percent body fat were the physiological variables considered for the comparison. Results showed significant statistical differences for mean body mass, percent body fat and VO2 max, indicating better fitness in workers doing manual work. These differences appear to be mainly due to the sedentary nature and lower energy expenditure of mechanized work, as both worker groups were similar in age and stature, lived together in forest camps, and ate the same food. Educational efforts aimed at machine operators should include healthy eating habits and encouraging more physical activity during leisure times.

Promoción de Salud: Un camino para la Estomatología del futuro / Health Promotion: the future way for Dentistry

En el presente trabajo se hace una reflexión sobre el papel de la promoción de salud como camino para la Estomatología del futuro. El propósito es actualizar y profundizar en estos aspectos. Se destaca la labor del estomatólogo del futuro con interés fundamental en el diálogo con la sociedad como un todo y capacidad técnica para educar a la población en aspectos de la salud Estomatológica de manera que consiga salud para todos mediante la capacitación a la comunidad para modificar estilos de vida que conducen a la prevención de enfermedades, favoreciendo el desarrollo personal y social de habilidades para que la comunidad ejerza un mayor control de su salud (AU)

Presently work is made a reflection on the paper of the promotion of health like road for the Estomatología of the future. The purpose is to upgrade and to deepen in these aspects. He/she stands out the work of the estomatólogo of the future with fundamental interest in the dialogue with the society like an everything and technical capacity to educate the population in aspects of the health Estomatológica so that it gets health for all by means of the training to the community to modify lifestyles that drive to the prevention of illnesses, favoring the personal and social development of abilities so that the community exercises a bigger control of its health (AU)

N-(2-pyridylmethyl)imines as azomethine precursors in catalytic asymmetric [3 + 2] cycloadditions.

An efficient Cu(I)-catalyzed asymmetric [3 + 2] cycloaddition of N-(2-pyridylmethyl) imines has been developed. In the presence of a Cu(CH(3)CN)(4)PF(6)/bisoxazoline catalyst system, high levels of enantioselectivity (up to 97% ee) and moderate to high exo selectivity were achieved with a wide variety of substituted dipolarophiles, including maleimides, fumarates, fumarodinitrile, enones, and nitroalkenes. The reaction with unsymmetrically substituted dipolarophiles is completely regioselective.

Evaluación fisiológica de postulantes a brigadistas forestales como proceso preventivo en seguridad y salud ocupacional / Physiological evaluation of applicants to forest fire fighters as preventive process of occupational safety and health

El objetivo del presente estudio es analizar la importancia de evaluar la aptitud física de las personas que postulan al cargo de brigadista para el combate de incendios forestales. Esta actividad es de altas demandas fisiológicas, genera fatiga y deshidratación provocando en casos extremos golpe de calor y muerte. La población estudiada correspondió a 1.431 varones entre 18 y 29 años de edad, evaluados en la Unidad de Ergonomía de la Universidad de Concepción entre los años 2001 y 2006. Los índices fisiológicos considerados fueron porcentaje corporal de masa grasa y capacidad aeróbica expresada en litros de oxígeno por minuto y en mililitros de oxígeno por minuto y por kilo de peso corporal. Los resultados mostraron que un 7,8 por ciento de los postulantes no tenía la aptitud física mínima para realizar esta actividad; que un 56,7 por ciento excedía los límites de masa grasa recomendados y que sólo un 34,3 por ciento de los postulantes cumplía con los tres requerimientos fisiológicos de referencia. En conclusión, cuando se establecen criterios para trabajos físicamente demandantes y se cuenta con técnicas de evaluación de fácil aplicación, no invasivas y de bajo costo, se dispone de una herramienta de prevención en seguridad y salud ocupacional, que entrega elementos de juicio para proteger y no exponer a trabajadores a labores cuyas exigencias sobrepasan sus capacidades.

The purpose of the present study is to analyze the importance of physiological methods as preventive tool for the protection of the applicants for the work of forest fire fighters. This activity demands heavy physical work, leading to fatigue and dehydration, and in extreme cases to heat stroke and death. The population studied corresponds to 1431 males from 18 to 29 years of age. They were evaluated at the Unit of Ergonomics of the University of Concepción between 2001 and 2006. The physiological variables considered were body fat percentage and aerobic capacity, expressed as liters of oxygen per minute and milliliters of oxygen per minute and per kilogram of body weight. The results showed that 7.8 percent didn't have the minimum physical fitness aptitude required to carry out this activity, 56,7 percent exceeded the limits of body fat and only 34,3 percent of the applicants fulfilled the three physiological criteria taken as reference. In conclusion, criteria for safety performance of heavy manual work and the availability of simple, non-invasive and low cost techniques for the evaluation of workers are powerful tools for the development of preventive actions to protect safety and health of the working population.

Histogénesis de esmalte dentario. consideraciones generales / Histogenesis of the dental enamel. General considerations

Se realizó una actualización científica sobre el proceso de formación del esmalte dentario para describir sus principales sucesos y analizar la relación funcional entre algunas proteínas y este proceso. El esmalte dentario se forma en el órgano de esmalte del germen dentario y las células productoras de este tejido son los ameloblastos. Durante la formación del tejido las capas de órgano y los ameloblastos sufren modificaciones que garantizan el aporte vascular al órgano, la deposición de la sustancia orgánica y su posterior mineralización donde intervienen las proteínas amelogenin, enalemin, ameloblastin y la colágena tipo X.

A scientific updating about the process of formation of the dental enamel was carried out to describe its main events and to analyze the functional relation between some proteins and this process. The dental enamel is formed in the enamel germ of the dental germ and the productive cells of this tissue are the ameloblasts. During the formation of the tissue, the coats of organ and the ameloblasts suffer modifications that guarantee the vascular contribute to the organ, the deposition of the organic substance and its subsequent mineralization where the proteins amelogenin, enalemin, ameloblastin and the type X collagen, intervene.