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This Perspective aims at providing a road map to computational heterogeneous photocatalysis highlighting the knowledge needed to boost the design of efficient photocatalysts. A plausible computational framework is suggested focusing on static and dynamic properties of the relevant excited states as well of the involved chemistry for the reactions of interest. This road map calls for explicitly exploring the nature of the charge carriers, the excited-state potential energy surface, and its time evolution. Excited-state descriptors are introduced to locate and characterize the electrons and holes generated upon excitation. Nonadiabatic molecular dynamics simulations are proposed as a convenient tool to describe the time evolution of the photogenerated species and their propagation through the crystalline structure of photoactive material, ultimately providing information about the charge carrier lifetime. Finally, it is claimed that a detailed understanding of the mechanisms of heterogeneously photocatalyzed reactions demands the analysis of the excited-state potential energy surface.

Kinetic rate constants are evaluated computationally for the spin-forbidden thermal relaxations of SCO complexes, unveiling their mechanism, and retrieving accurate TLIESST predictions.

El propósito del presente artículo es revisitar, desde otra perspectiva, la de la maternidad, el papel que dos de las temáticas centrales del Surrealismo, las mujeres y el amor, tuvieron en el movimiento. Para el Surrealismo, la maternidad, necesariamente opuesta al deseo, constituía una barrera para la liberación absoluta de las pasiones a la que confiaban el proyecto revolucionario. Desde el punto de vista femenino, la anulación del sujeto que suponía la maternidad era también la de sus deseos y, por tanto, una limitación para su desarrollo como artistas. Ironizando sobre las fórmulas anteriores y creando otras nuevas, la iconografía surrealista de la maternidad será ante todo la de una deconstrucción: la de la imagen que la presentaba como sinónimo de felicidad femenina., The aim of this article is to revise the role of women and love in surrealism from another perspective: that of motherhood. For the surrealists, motherhood, inevitably opposed to desire, was a barrier to the absolute liberation of the passions, a liberation on which they relied in their revolutionary project. From the feminine point of view, the annulment of the subject that motherhood entailed was also an annulment of her desires and so a limitation for the development of artists. While ironizing on previous iconographies and establishing new formulas, the surrealist iconography of motherhood will be, above all, that of a deconstruction: that of the image presenting the mother as a synonym of female happiness.

MXenes compounds, a recently discovered family of 2D materials, have been found to become semiconductors and photoactive when their pristine surfaces are functionalized with an electronegative termination. MXenes may present...

The electron-transfer flavoprotein dehydrogenase gene (ETFDH) encodes the ETF-ubiquinone oxidoreductase (ETF-QO) and has been reported to be the major cause of multiple acyl-CoA dehydrogenase deficiency (MADD). In this study, we present the clinical and molecular diagnostic challenges, at the DNA and RNA levels, involved in establishing the genotype of four MADD patients with novel ETFDH variants: a missense variant, two deep intronic variants and a gross deletion. RNA sequencing allowed the identification of the second causative allele in all studied patients. Simultaneous DNA and RNA investigation can increase the number of MADD patients that can be confirmed following the suggestive data results of an expanded newborn screening program. In clinical practice, accurate identification of pathogenic mutations is fundamental, particularly with regard to diagnostic, prognostic, therapeutic and ethical issues. Our study highlights the importance of RNA studies for a definitive molecular diagnosis of MADD patients, expands the background of ETFDH mutations and will be important in providing an accurate genetic counseling and a prenatal diagnosis for the affected families.

Background The impairment of the hepatic enzyme phenylalanine hydroxylase (PAH) causes elevation of phenylalanine levels in blood and other body fluids resulting in the most common inborn error of amino acid metabolism (phenylketonuria). Persistently high levels of phenylalanine lead to irreversible damage to the nervous system. Therefore, early diagnosis of the affected individuals is important, as it can prevent clinical manifestations of the disease. Methods In this report, the biochemical and genetic findings performed in 223 patients diagnosed through the Portuguese Neonatal Screening Program (PNSP) are presented. Results Overall, the results show that a high overlap exists between different types of variants and phenylalanine levels. Molecular analyses reveal a wide mutational spectrum in our population with a total of 56 previously reported variants, most of them found in compound heterozygosity (74% of the patients). Intragenic polymorphic markers were used to assess the haplotypic structure of mutated chromosomes for the most frequent variants found in homozygosity in our population (p.Ile65Thr, p.Arg158Gln, p.Leu249Phe, p.Arg261Gln, p.Val388Met, and c.1066‐11G>A). Conclusion Our data reveal high heterogeneity at the biochemical and molecular levels and are expected to provide a better understanding of the molecular basis of this disease and to provide clues to elucidate genotype–phenotype correlations., The present study identify and characterize the variants underlying PKU in affected individuals in the Portuguese PKU/HPA cohort. Biochemical data, haplotic analysis and genetic findings performed in 223 patients diagnosed through the Portuguese Neonatal Screening Program (PNSP) is presented. The information obtained will improve the diagnostic applicability of mutational analysis and the capacity to predict the evolution of the disease.

Galanin (Gal) is a neuropeptide with multiple functions that is widely expressed in the central and peripheral nervous systems of vertebrates. Anatomical and functional evidence suggests a possible role in regulating reproduction in fishes. To test this possibility, we have isolated and characterized two gal alternative transcripts in European sea bass (Dicentrarchus labrax) that encode two prepropeptides, respectively of 29 (gal_MT853221) and 53 (gal_MT853222) amino acids. The two gal transcripts are highly expressed in brain, pituitary and gonads, and appear to be differentially regulated in males and females. In males, gal_MT853222 in the hypothalamus and gal_MT853221 in the pituitary were downregulated with the progression of spermatogenesis (stages I-III). Both transcripts are downregulated in testicles of 1-year (precocious) and 2-year spermiating males compared to immature fish of the same age. Gal peptides and receptors are expressed throughout ovarian development in the hypothalamic-pituitary-gonadal (HPG) axis of females. In the testis, immunoreactive Gal-29 and Gal-53 peptides were detected in blood vessels and Leydig cells during the spermatogenesis stages I-III but Gal immunostaining was barely undetected in more advanced stages. In the ovary, both peptides localized in interstitial cells and blood vessels and in theca cells surrounding the maturing oocytes. The immunolocalization of galanin in Leydig and theca cells suggests a possible role in steroid production regulation. The different pattern of gal expression and Gal localization in the testis and ovary may suggest the possibility that androgens and estrogens may also regulate Gal gene transcription and translation. Altogether, this study showed evidence for the possible involvement of locally produced Gal in gametogenesis and that its production is differentially regulated in male and female gonads., This research was funded by the Portuguese national funds from FCT (Foundation of Science and Technology, I.P.) through projects UIDB/04326/2020 and PTDC/MAR-BIO/3890/2012 and by the European Union Seventh Framework Programme AQUAEXCEL (Grant Agreement 262336, TNA project 318). AG and GM were supported by Spanish MINECO (AGL2015-67477-C2-1-R) and CSIC (201640E073). R.S.T.M and P.I.S.P were supported by FCT under contracts of Norma transitória (DL 57/2016/CP1361/CT0021 and DL57/2016/CP6321/CT0015, respectively) with Universidade do Algarve. We acknowledge Zélia Velez for the help during sampling, Deborah Power for IHC advice and Victoria Alvarado and Alicia Felip for providing hypothalamus and pituitary RNA panels.

Glutaric aciduria type 1 (GA-1) is a rare but treatable inherited disease caused by deficiency of glutaryl-CoA dehydrogenase activity due to GCDH gene mutations. In this study, we report 24 symptomatic GA-1 Brazilian patients, and present their clinical, biochemical, and molecular findings. Patients were diagnosed by high levels of glutaric and/or 3-hydroxyglutaric and glutarylcarnitine. Diagnosis was confirmed by genetic analysis. Most patients had the early-onset severe form of the disease and the main features were neurological deterioration, seizures and dystonia, usually following an episode of metabolic decompensation. Despite the early symptomatology, diagnosis took a long time for most patients. We identified 13 variants in the GCDH gene, four of them were novel: c.91 + 5G > A, c.167T > G, c.257C > T, and c.10A > T. The most common mutation was c.1204C > T (p.R402W). Surprisingly, the second most frequent mutation was the new mutation c.91 + 5G > A (IVS1 ds G-A + 5). Our results allowed a complete characterization of the GA-1 Brazilian patients. Besides, they expand the mutational spectrum of GA-1, with the description of four new mutations. This work reinforces the importance of awareness of GA-1 among doctors in order to allow early diagnosis and treatment in countries like Brazil where the disease has not been included in newborn screening programs. info:eu-repo/semantics/publishedVersion

The equivalent core model, or the Z + 1 approximation, has been used to interpret the binding energy, BE, shifts observed in X-ray photoelectron spectroscopy, XPS; in particular to relate these shifts to their origin in the electronic structure of the system. Indeed, a recent paper has claimed that the equivalent core model provides an intuitive chemical view of XPS BE shifts. In the present paper, we present a detailed comparison of the electronic structure provided from rigorous core-hole theory and from the equivalent core model to assess the validity and the utility of the use of the equivalent core model. This comparison shows that the equivalent core model provides a qualitative view of the different properties of initial and core-hole electronic structure. It is also shown that a very serious limitation of the equivalent core model is that it fails to distinguish between initial and final state contributions to the shifts of BEs which seriously reduces the utility of the information obtained with the equivalent core model. Indeed, there is a danger of making an incorrect assignment of the importance of relaxation because the equivalent core model appears to stress the role of final state effects. Given the importance of the distinction of initial and final state effects, we provide rigorous definitions of these two effects and we discuss an example where an incorrect interpretation was made based on the use of the equivalent core model.

The Portuguese Newborn Screening Program is a public health program that started in 1979, screening for PKU, being totally supported by public funds. It's a non-mandatory well implemented program that testes about 99.9% of Portuguese newborns. In the actual screening panel encompasses 26 disorders, including inborn errors of metabolism, congenital hypothyroidism and cystic fibrosis. Sample collection is advised to be made at 3rd day of life and treatment begins in average by the 10th day. Every testes are performed in one single national laboratory, that processes about 88,000 samples/year. In the 41 years of program existence, more than 3,800,000 newborns were screened and 2,130 affected newborns detected, reflecting the positive impact of the Program in the population. Future perspectives include the increase of program value in terms of public health by optimizing the screening of the disorders already screened and evaluation the possibility of adding others.El Programa Portugués de Cribado Neonatal es un programa de Salud Pública a nivel nacional, que tuvo su inicio en 1979 con el cribado de la fenilcetonuria y es financiado totalmente por el Estado portugués. Se trata de un programa no obligatorio, con una tasa de cobertura del 99,8%, en el que hoy en día se criban veintiséis enfermedades, incluyendo metabolopatías, hipotiroidismo congénito y fibrosis quística. La toma de muestra se hace al 3er día de vida y el tratamiento de los neonatos afectos empieza en torno al 10º día. Todos los análisis están centralizados en un único laboratorio, que procesa aproximadamente 88.000 muestras al año. En los últimos cuarenta y un años se cribaron más de 3.800.000 neonatos y se detectaron 2.130 niños afectados, lo que es un indicador del impacto del programa en la población. Los desafíos futuros incluyen la búsqueda de nuevas estrategias para incrementar el valor del programa, donde se evalúen nuevas enfermedades a cribar y la optimización del cribado actual.

The influence of electron correlation into the decomposition of core level binding energy shifts, measured by X-ray photoelectron spectroscopy (XPS), into initial and final effects is analysed for a series of molecules where these effects are noticeable. Moreover, the series of molecules is chosen in such a way that electron delocalization and increasing number of electrons may provide a large screening of the core hole. A detailed analysis shows that the Hartree-Fock decomposition is biased whereas a physically meaningful decomposition is obtained when electron correlation effects are taken into account. The results show that in this case, trends in core level binding energy shifts are driven by initial state effects thus providing further support to the use of these observable quantities to interpret changes in the chemical bond in the neutral molecule rather than on the core ionized cation. Consequences for the theoretical interpretation of XPS data in materials and surface science are discussed.

The non-specific immunity can induce iron deprivation as a defense mechanism against potential bacterial pathogens, but little information is available as to its role in Antarctic fish. In this study the response of iron metabolism related genes was evaluated in liver and head kidney of the Antarctic notothenoids Notothenia coriiceps and Notothenia rossii 7 days after lipopolysaccharide (LPS) injection. Average plasma Fe2+ concentration was unaffected by treatment in any of the species. The gene expression response to LPS varied between tissues and species, being stronger in N. coriiceps and more prominent in the head kidney than liver. The reaction to LPS was marked by increased individual variability in most genes analyzed, even when the change in expression was not statistically significant, suggesting different individual sensitivity and coping responses in these wild fish. We found that iron related genes had an attenuated and homogenous response to LPS but there was no detectable relationship between plasma Fe2+ and gene expression. However, overall in both tissues and species LPS exposure set a multilevel response that concur to promote intracellular accumulation of iron, an indication that Antarctic Notothenoids use innate nutritional immunity as a resistance mechanism against pathogens. FCT-NSFC/0002/2016; CCMAR/Multi/04326/2013; PTDC/BIAANM/3484/2014 info:eu-repo/semantics/publishedVersion

Investigation of the excited state decay dynamics of transition metal systems is a crucial step for the development of photoswitchable molecular based ma- terials with applications in growing fields as energy conversion, data storage or molecular devices. The photophysics of these systems is an entangled problem arising from the interplay of electronic and geometrical rearrangements that take place on a short time scale. Several factors play a role in the process: various electronic states of di↵erent spin and chemical character are involved, the system undergoes important structural variations and several nonradiative processes can occur. Computational chemistry is a useful tool to get insight into the micro- scopic description of the photophysics of these materials since it provides unique information about the character of the electronic spin states involved, the ener- getics and time evolution of the system. In this review article, we present an overview of the state of the art methodologies available to address the several aspects that have to be incorporated to properly describe the deactivation of excited states in transition metal complexes. The most recent developments in theoretical methods are discussed and illustrated with examples.

The deactivation pathway of the light-induced spin crossover process in two Fe(II) complexes has been studied by combining density functional theory calculations for the geometries and the normal vibrational modes and highly correlated wave function methods for the energies and spin orbit coupling effects. For the two systems considered, the mechanism of the photoinduced conversion from the low-spin singlet to the high-spin quintet state implies two intersystem crossings through intermediate triplet states. However, for the [Fe(mtz)(6)](2+) complex, the process occurs within few picoseconds and involves uniquely metal-centered electronic states, whereas for the [Fe(phen)(3)](2+) system the deactivation channel involves both metal to ligand charge transfer and metal-centered states and takes place in a femtosecond time scale.

X-ray Photoelectron Spectroscopy (XPS) applied to N-doped graphene leads to a rather broad N(1s) core level signal that, based on different sources available in the literature, is most often interpreted by fitting the experimental spectra to three peaks. The resulting N(1s) features are assigned to graphitic, pyrrolic, and pyridinic nitrogen, even if these are far from being uniquely defined in the literature. This broadly accepted interpretation has been questioned by recent accurate Hartree-Fock calculations concluding that graphitic and pyrrolic N(1s) core level binding energies are too close to be distinguished. Consideration of models with N in other so far unexplored environments such as N dimers or N at defects show some variations in the calculated core level binding energies. However, these are not large enough to justify a third peak and suggest that the usual three peaks interpretation of the N(1s) XPS in N-doped graphene may be an artefact caused by the fitting procedure. New measurements have been carried out for samples of N-doped graphene and the obtained N(1s) spectra fitted to two or three peaks. It turns out that the spectra can be equally fitted using two or three peaks but only the former is consistent with the results of the unbiased ab initio calculations which calls for a revision of the usual assignment.

The ability of density functional theory (DFT) based methods to predict the multiplet splitting arising from the core hole ionization of molecules such as NO and O2, exhibiting an open shell grounds state, is explored. In the NO molecule, N(1s) or O(1s) ionization leads to 3Π and 1Π multiplets whereas for O2, the presence of an O(1s) core hole leads to doublet and quartet multiplets with distinct BEs. Multiplet splittings obtained using different exchange-correlation functionals show an overall good agreement with experiment and minor variations within the functionals studied when spin contamination resulting from unrestricted DFT calculations is accounted for.

In this paper, the contribution of many body effects to the X-ray photoelectron spectroscopy, XPS, of an NO molecule are studied using wavefunction theory where the specific consequences of different many-body terms are examined and contrasted. It is shown that there is a differential importance of the many-body effects for the different configurations involved in the XPS. These are the ground, initial state configuration and final, N(1s) and O(1s) core-hole ionic configurations. The consequences of the many-body effects are examined for the binding energies, BEs, to the two final state multiplets, triplet and singlet, for each of the core ions and for the relative intensities of the XPS transitions to these multiplets. The many body effects examined are those described as static effects that arise for individual terms that are important. The objective is to understand the chemical and physical origins that determine the importance of the correlation effects for the XPS, rather than to obtain very accurate predictions of the BEs. An important theoretical construct that is tested and justified is the equivalent core approximation where the core ionized atom is replaced by the next higher element in the periodic table. This construct allows us to establish a correlation for the relative importance of the many-body effects in terms of effective charges of the different atoms. This is a correlation that has not been considered before and that we expect may have general relevance. The potential of the effects that we have identified for the XPS of NO to be relevant for the XPS of more complex, condensed phase systems is considered.

Investigation of the excited state decay dynamics of transition metal systems is a crucial step for the development of photoswitchable molecular based ma- terials with applications in growing fields as energy conversion, data storage or molecular devices. The photophysics of these systems is an entangled problem arising from the interplay of electronic and geometrical rearrangements that take place on a short time scale. Several factors play a role in the process: various electronic states of di↵erent spin and chemical character are involved, the system undergoes important structural variations and several nonradiative processes can occur. Computational chemistry is a useful tool to get insight into the micro- scopic description of the photophysics of these materials since it provides unique information about the character of the electronic spin states involved, the ener- getics and time evolution of the system. In this review article, we present an overview of the state of the art methodologies available to address the several aspects that have to be incorporated to properly describe the deactivation of excited states in transition metal complexes. The most recent developments in theoretical methods are discussed and illustrated with examples.

Core level binding energies, directly measured by X-ray photoelectron spectroscopy (XPS), provide unique information regarding the chemical environment of atoms in a given system. However, interpretation of XPS in extended systems may not be straightforward and requires assistance from theory. The different state-of-the-art theoretical methods commonly used to approach core level binding energies and their shifts with respect to a given reference are reviewed and critically assessed with special emphasis on recently developed theoretical methods and with a focus on future applications in materials and surface sciences.

Spin-orbit couplings have been calculated in twenty snapshots of a molecular dynamics trajectory of [Fe(bpy)3]2+ to address the importance of geometrical distortions and second-order spin-orbit coupling on the intersystem crossing rate constants in the light-induced spin crossover process. It was found that the effective spin-orbit coupling between the 3MLCT and 5T2 state is much larger than the direct coupling in the symmetric structure, which opens the possibility of a direct 3MLCT-5T2 deactivation without the intervention of triplet metal-centered states. Based on the calculated deactivation times, we conclude that both the direct path- way and the one involving intermediate triplet states are active in the ultrafast population of the metastable HS state, bringing in agreement two experimental observations that advocate for either deactivation mechanism. This resolves a long-standing dispute about the deactivation mechanism of Fe(II)-polypyridyl complexes in particular, and about light-induced magnetism in transition metal complexes in general.

The deactivation pathway of the light-induced spin crossover process in two Fe(II) complexes has been studied by combining density functional theory calculations for the geometries and the normal vibrational modes and highly correlated wave function methods for the energies and spin-orbit coupling effects. For the two systems considered, the mechanism of the photoinduced conversion from the low-spin singlet to the high-spin quintet state implies two intersystem crossings through intermediate triplet states. However, for the [Fe(mtz)

The neuropeptide galanin (Gal) is a putative factor regulating puberty onset and reproduction through its actions on the pituitary. The present study investigated the pituitary responsiveness to galanin and the patterns of galanin receptors (Galrs) expression throughout the reproductive cycle of two years old male European sea bass (Dicentrarchus labrax), an important aquaculture species. Quantitative analysis of pituitary and hypothalamus transcript expression of four galr subtypes revealed differential regulation according to the testicular developmental stage, with an overall decrease in expression from the immature stage to the mid-recrudescence stage. Incubation of pituitary cells with mammalian 1–29 Gal peptide induced significant changes in cAMP concentration, with sensitivities that varied according to the testicular development stages. Furthermore 1–29 Gal was able to stimulate both follicle stimulating hormone (Fsh) and luteinizing hormone (Lh) release from pituitary cell suspensions. The magnitude of the effects and effective concentrations varied according to reproductive stage, with generalized induction of Fsh and Lh release in animals sampled in January (full spermiation). The differential expression of galrs in pituitary and hypothalamus across the reproductive season, together with the differential effects of Gal on gonadotropins release in vitro strongly suggests the involvement of the galaninergic system in the regulation the hypothalamus-pituitary-gonad axis of male sea bass. This is to our knowledge the first clear evidence for the involvement of galanin in the regulation of reproduction in non-mammalian vertebrates., This work was supported by the Portuguese Foundation for Science and Technology [grant numbers SFRH/BPD/84033/2012, PTDC/MAR-BIO/3890/2012, UID/Multi/04326/2013]; the European Union Seventh Framework Programme [AQUAEXCEL grant number 262336]; the Spanish Ministry of Science and Innovation (MICINN) and the Spanish Ministry of the Economy and Competitiveness (MINECO) [KISSCONTROL project, AGL2009-11086]; the Spanish Ministry of the Economy and Competitiveness and the Regional Government of Valencia (REPROBASS project, PROMETEOII/2014/051).

We use a total energy difference approach to explore the ability of various density functional theory based methods in accounting for the differential effect of static electron correlation on the C(1s) and O(1s) core level binding energies (BEs) of the CO molecule. In particular, we focus on the magnitude of the errors of the computed C(1s) and O(1s) BEs and on their relative difference as compared to experiment and to previous results from explicitly correlated wave functions. Results show that the different exchange-correlation functionals studied here behave rather erratically and a considerable number of them lead to large errors in the BEs and/or the BE shifts. Nevertheless, the TPSS functional, its TPSSm and RevTPSS derivations, and its corresponding hybrid counterpart, TPSSh, perform better than average and provide BEs and BE shifts in good agreement with experiment.

Objective Birth prevalence of Cobalamin (Cbl) C or D defects in Portugal is an estimated 1:85,000, one of the highest worldwide. We compared the genotype/phenotype of patients identified with CblC or CblD before and after the implementation of expanded newborn screening. Methods Twenty-five Portuguese CblC/D patients, 14 symptomatic and 11 identified through screening, were diagnosed using gas chromatography or tandem mass spectrometry. Molecular characterization was performed through the study of MMACHC and MMADHC genes. Results The most common MMACHC mutation, c.271dupA, was present in 100% of MMACHC alleles of all CblC screened patients, in contrast with the 61% identified before expanded newborn screening. All studied cases (except one, who presented a CblD deficiency) presented a CblC defect. More CblC late-onset patients were diagnosed before the introduction of newborn screening than in the post newborn screening era, probably because some early onset patients died without a definitive diagnosis. Conclusion The molecular data found in this cohort contribute to the improvement of screening and diagnosis of Cbl defects and would enable a confirmatory diagnosis of these patients, reducing the need for complex, costly, laborious, and time-consuming biochemical/enzymatic tests.

10.1039/c3dt52027g The spin crossover behavior of the two [Fe(mtz)6](2+) complexes occupying different lattice sites in Fe(mtz)6(BF4)2 is addressed by combining quantum chemical calculations with a careful analysis of the crystal structure. It is first established from the calculations that the energy difference between high spin and low spin states depends on the orientation of the tetrazole ligands; small rotation angles favor the low spin state, while for angles larger than ~20° the high spin state is more stable. The crystal structure shows that the two complexes have different average rotation angles of the ligands. It is larger for the site that remains HS down to low temperatures and smaller for the site that shows spin crossover to LS. The origin of the different rotation angles is found to be determined by a subtle interplay amongst steric repulsion between the ligands, HF interactions between the complex and the counterions, and intersite interactions involving NH contacts and p-p interactions between the N[double bond, length as m-dash]N double bonds of the tetrazole rings.

The deficiency of 3-methycrotonyl-CoA carboxylase (3-MCC; EC 6.4.1.4) is an autosomal recessive organic aciduria that is included in the newborn screening programs of several countries. This study reports data mainly obtained from the Portuguese newborn screening program collected over a ten-year period. Analysis of the MCCC1 and MCCC2 genes yielded 26 previously unreported mutations and a variant of clinically unknown significance. These mutations are discussed in the context of their likely impact on the function of the 3-MCC enzyme, with a view to exploring whether a phenotype-genotype correlation might be discerned. Further, these mutations were analysed in the context of what is known of the MCCC1 and MCCC2 mutational spectra, information that will be useful in both clinical and laboratory practice.

INTRODUCTION: The Portuguese Neonatal Screening Programme (PNSP) was started in 1979 for phenylketonuria (2,590,700 newborns screened; prevalence 1:11,031) and, shortly after, for congenital hypothyroidism (2,558,455 newborns screened; prevalence 1:3,174). In 2004, expanded neonatal screening was implemented in the National Laboratory. The programme is not mandatory and has 99.8% coverage of the country (including Madeira and the Azores islands). MATERIAL AND METHODS: In the past 4 years, 316,243 neonates were screened with the use of tandem mass spectrometry (MS/MS) to test for selected amino acids and acylcarnitines. RESULTS: During this time, 132 patients were identified with 24 different inherited metabolic diseases (classic forms and variants). To date, the global frequency for all disorders integrated into the PNSP is estimated to be 1:1,380, with 1:2,396 for metabolic disorders. A total of 379 tests (0.12%) were classified as having false positive results, yielding an overall specificity of 99.9%. Despite the low frequency of several disorders, the positive predictive value of the overall MS/MS screening was found to be 26%, reflecting high diagnostic specificity of the method. Diagnostic sensitivity of extended screening for the different groups of disorders was 100%. Eight cases of maternal disorders [three glutaric aciduria type I, one carnitine transporter defect, and four 3-methylcrotonyl coenzyme A (CoA) carboxylase deficiency] were also detected through newborn screening. CONCLUSIONS: Our data support the advantage of a centralised laboratory for screening an elevated number of samples and making decisions if relying on a clinical network able to provide fast treatment and a good outcome in the screened cases.

A systematic density functional study of NO dissociation on Rh(111), Cu(111), and two different RhCu(111) bimetallic surfaces was conducted using a periodic supercell approach. Properties of the transition states, energy barriers, and transition state theory reaction rates were obtained for relevant situations involving NO adsorbed on different compositions of fcc and hcp sites. The results demonstrate that the superior activity of Rh versus Cu toward NO dissociation has its origin in the stronger adsorption on the former surface, which permits NO dissociation without the need for extra energy to the system. Moreover, the presence of Cu atoms on a Rh surface exerts a promoter effect by decreasing the energy barrier with respect to the value for the single crystal surface. In contrast, the presence of Rh atoms on a Cu surface has a poisoning effect. Analysis of the adsorption energies provides some important clues as to the modification of the corresponding energy barriers induced by the presence of the second metal. The results indicate that it is possible to improve the catalytic properties of Rh surfaces by adding small quantities of Cu, in agreement with previous experimental findings.

The effect of spin-orbit coupling is assessed through the spin-orbit state interaction method. This method involves a two-step procedure to include both dynamical electron correlation effects and spin-orbit effects on the relative energies of the low-lying electronic states. Accurate energies of the spin free states are obtained with the complete active space self-consistent field/complete active space second-order perturbation theory (CASSCF/CASPT2) procedure. Second, the spin-orbit coupling is taken into account by interaction of the CASSCF states using the CASPT2 relative energies. The method is validated on the Co2+ ion in vacuum and in the ionic insulator CoO. Afterward the method is applied to CoCl2(PPh3)2 and the dinuclear complexes [TM2Cl6]2− (TM = Mn, Fe, Co). For the monomeric species, the results compare favorable with experimental data or fully relativistic benchmarks. We discuss the difficulties to interpret the dimer results in terms of the parameters that are usually derived from experiment. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006

We recently developed a scheme for first-principles calculations of hopping matrix elements between localized states in extended systems. We apply the scheme to the determination of double exchange (DE) parameters in lightly hole-doped LaMnO(3) and electron-doped CaMnO(3). DE is one of the important factors for understanding the properties of doped manganites. The calculations are based on the construction of wave functions for localized hole states or localized electron states for large embedded clusters. The wave functions of these clusters are expressed in terms of localized orbitals, obtained from calculations on smaller units, or "fragments," centered around a transition metal ion. The starting point of electronic states expressed in terms of localized orbital sets is conceptually attractive. It also allows for a rigorous treatment of local electron correlation and electronic relaxation effects. In the present study, the fragments are embedded [MnO(6)] units. The large clusters contain either two or four Mn ions and all neighboring oxygen ligands. The results are compared with conventional embedded cluster calculations. In both compounds, the effective hopping matrix elements, or "double exchange" (DE) parameters, in the ab planes (in the Pbnm space group) are larger than along the c axes. We found nearly perfect agreement with the Anderson-Hasegawa model for the spin dependence of the DE parameters. Nearest-neighbor parameters are more than one order of magnitude larger than next nearest-neighbor parameters. In LaMnO(3) the DE in the ab planes is approximate to -0.26 eV. If there were no Jahn-Teller distortion present in the material, it would have been twice as large. In CaMnO(3), the corresponding nearest-neighbor DE parameter for hopping of a doped electron in the ab planes is only approximate to -0.17 eV, due to the antiparallel spin coupling. However, since this interaction is much larger than the exchange coupling, we suggest that it induces local ferromagnetic clusters around the doped electrons. (C) 2006 Wiley Periodicals, Inc.

Adsorption at surfaces can be modelled using a periodic supercell approach or using finite clusters. For many systems and properties these models are complementary and often the most productive way to work is to use a combination of these techniques. If reliable data is to be obtained it is essential that convergence is achieved with respect to the size of supercell and cluster. This work discusses the convergence of chemisorption properties of H on Cu(0 0 1) with respect to the cluster size. To this end,calculations of the H binding energy and equilibrium distance are reported for cluster models of increasing size containing up to 77 metal atoms. Likewise,periodic slab model calculations are used to provide the corresponding values towards which the cluster approach should converge. In many previous studies of a wide variety of systems it has been established that computed equilibrium distances converge rapidly with respect to cluster size. Here,a systematic study of the dependence on cluster size shows that,for adsorption in the fourfold site,convergence is not achieved even for very large clusters. The reason for this poor convergence is seen to be the inability of the cluster model to reproduce accurately the charge density and electrostatic potential of the crystalline surface. 2002 Elsevier Science B.V. All rights reserved.

A model based on the use of ab initio quantum chemical explicitly correlated wave functions is proposed to study the electronic transfer reaction between an adsorbate and a metallic electrode. In this model, the effects of the electrode potential are simulated through the application of a uniform external electric field. This field exerts an influence on the relative stability of the two electronic states that are mainly involved in the electron transfer. These electronic states have the transferred electron localized either in the electrode or in the adsorbate. The model has been applied to the electron transfer between halides and a cluster model representation of the Cu(100) single-crystal electrode. A linear correlation between the electric field intensity at which the two electronic states involved in the charge-transfer process become degenerate and the normal reduction electrode potential is found. The existence of this linear correlation indicates that the proposed model contains the essential physics governing the trend of halide oxidation at a metal electrode.

First principles based density functional methods and theoretical models have been used to investigate the reactivity of different RhCu alloys toward molecular hydrogen dissociation. For pure Rh(111), it is predicted that H2 can either dissociate spontaneously or be physisorbed as molecular hydrogen. These predictions agree with recent experimental findings. The simple addition of a Cu atom to a Rh-rich environment is enough to eliminate the presence of the energy minimum associated with molecularly adsorbed hydrogen and to convert H2 dissociation in an activated process. From the present results it is concluded that increasing the Cu content may lead to a change in the active site and permits us to speculate about the enhancement on the irreversible hydrogen uptake on going from Rh to RhCu alloys with a small Cu content.

The performance of the complete active space second-order perturbation theory (CASPT2) to accurately predict magnetic coupling in a wide series of molecules and solid state compounds has been established. It is shown that CASPT2, based on a reference wave function that only includes the effects described by the Anderson or Hay−Thibeault−Hoffmann model, correctly reproduces all experimental trends. For a complete quantitative agreement with experiment (or with accurate results arising from the difference dedicated configuration interaction method), it is necessary to include effects that go beyond the Anderson model in the reference wave function. The CASPT2 method is computationally less demanding than CI based methods and, hence, allows us to extend the study of magnetic coupling parameters to larger molecules or systems with elevated spin moments. Moreover, CASPT2 provides a reliable and accurate alternative to density functional based methods that require the use of a broken symmetry approach.

The low-lying electronic transitions in a peroxy radical, wSi-O-O¿, a fundamental radiation induced point defect in silicon dioxide, have been investigated by means of ab initio multiconfiguration perturbation theory calculations, CASPT2, and cluster models. The accuracy of the computed transition energies and intensities as predicted by the CASPT2 approach has been checked by studying the exited state properties of two molecular analogues, the HOO¿ and CH3OO¿ radicals, and of a well-characterized paramagnetic defect in silica, the nonbridging oxygen center, wSi-O¿, for which unambiguous assignments exist. We found that the peroxy radical gives rise to two optical absorption bands, a very weak one at 0.7 eV and an intense one at 5.49 eV, in agreement with the experimental assignments of Radzig [V. A. Radzig, Chem. Phys. Reports 14, 1206 (1995)].

A density functional cluster model approach has been applied to the study of the interaction of molecular hydrogen with two different cluster models of the PdCu(111) surface corresponding to a different formal alloy composition both having a single Pd atom in the surface. Despite the similar surface morphology of the two bimetallic clusters, they exhibit a rather different reactivity toward molecular hydrogen. The coordination of the surface Pd atom to other Pd atoms in the second layer appears to be necessary for this atom be able to trap and dissociate molecular hydrogen with a very low energy cost, thus being a potential active site for catalysis. This important result points out that electronic, or ligand, effects do also play an important role in the activity of the PdCu(111) surface sites toward molecular hydrogen.

due to the presence of the Ag 0 impurity. Moreover, from the present results, it is predicted that on passing to NaCl:Ag 0 the CT onset would be out of the optical range while the 5s-5p transition would undergo a redshift of 0.3 eV. These conclusions, which underline the different character of involved orbitals, are consistent with experimental findings. The existence of a CT transition in the optical range for an atom inside an ionic host is explained by a simple model, which also accounts for the differences with the more common 3d systems. The present study sheds also some light on the R dependence of the s 2 - sp transitions due to s 2 ions like Tl 1 .

The equilibrium geometry of Ag 0 centers formed at cation sites in KCl has been investigated by means of total-energy calculations carried out on clusters of different sizes. Two distinct methods have been employed: First, an ab initio wave-function based method on embedded clusters and second, density-functional theory ~DFT! methods on clusters in vacuo involving up to 117 atoms. In the ab initio calculations the obtained equilibrium Ag 0 -Cl 2 distance Re is 3.70 A, implying a large outward relaxation of 18%, along with 7% relaxation for the distance between Ag 0 and the first K 1 ions in ^100& directions. A very similar result is reached through DFT with a 39-atom cluster. Both approaches lead to a rather shallow minimum of the total-energy surface, the associated force constant of the A1g mode is several times smaller than that found for other impurities in halides. These conclusions are shown to be compatible with available experimental results. The shallow minimum is not clearly seen in DFT calculations with larger clusters. The unpaired electron density on silver and Cl ligands has been calculated as function of the metal-ligand distance and has been compared with values derived from electron-paramagnetic resonance data. The DFT calculations for all cluster sizes indicate that the experimental hyperfine and superhyperfine constants are compatible whenRe is close to 3.70 A. The important relation between the electronic stability of a neutral atom inside an ionic lattice and the local relaxation is established through a simple electrostatic model. As most remarkable features it is shown that ~i! the cationic Ag 0 center is not likely to be formed inside AgCl, ~ii! in the Ag 0 center encountered in SrCl2, the silver atom is probably located at an anion site, and ~iii! the properties of a center-like KCl:Ag 0 would experience significant changes under hydrostatic pressures of the order of 6 GPa.

Ab initio cluster model wave functions are used to predict the existence of localized excited states in MgO, ${\mathrm{Al}}_{2}{\mathrm{O}}_{3},$ and ${\mathrm{SiO}}_{2}$ arising from metal $2p$ core-level excitations. Theoretical values obtained at different levels of theory result in a quantitative agreement with experiment, and the use of different models permits us to quantify the different contributions to the final excitation energy. The most important contribution is atomic in nature; a meaningful zero-order approximation is that in MgO and ${\mathrm{Al}}_{2}{\mathrm{O}}_{3}$ the exciton can be assigned to a ${M(2p}^{6})\ensuremath{\rightarrow}{M(2p}^{5}{3s}^{1})$-like excitation, where $M=\mathrm{Mg}$ or Al. For the atomic models, the singlet-triplet exchange in the excited configuration is in good agreement with experiment. In addition, the solid-state effects on this exchange energy predicted by experiment are well reproduced by the cluster models representing MgO and ${\mathrm{SiO}}_{2},$ whereas a less clear situation appears in ${\mathrm{Al}}_{2}{\mathrm{O}}_{3}.$ The open-shell orbital in the final state has, however, important contributions from the ions near the atomic site where excitation occurs. Nevertheless, the final state appears to be localized in space without any a priori assumption, the localization following from the hole-particle interaction implicitly induced in the final-state wave function. The Madelung field reduces the excitation energy with respect to the atomic value; the effect of neighboring atoms, mainly Pauli repulsion, acts in the opposite way; and electronic correlation effects decrease it again. In agreement with the covalent nature of ${\mathrm{SiO}}_{2},$ the exciton cannot be simply understood as arising from a $\mathrm{Si}{(2p}^{6})\ensuremath{\rightarrow}\mathrm{Si}{(2p}^{5}{3s}^{1})$ in a fully oxidized Si cation.

The key parameters associated to the thermally induced spin crossover process have been calculated for a series of Fe(II) complexes with mono-, bi-, and tridentate ligands. Combination of density functional theory calculations for the geometries and for normal vibrational modes, and highly correlated wave function methods for the energies, allows us to accurately compute the entropy variation associated to the spin transition and the zero-point corrected energy difference between the low-and high-spin states. From these values, the transition temperature, T-1/2, is estimated for different compounds. (C) 2014 AIP Publishing LLC.

The character of the low-lying excited states of diatomic CuCl is studied primarily by means of the complete active space self-consistent field (CASSCF), method and a second order perturbation approach with the CASSCF wave function as reference state [complete active space perturbation theory to second order (CASPT2)]. Far comparison, the lower levels of the spectra of the Cu+ ion are also analyzed. A first order treatment of the scalar relativistic effects, the mass-velocity and Darwin terms, is included in the calculations. The importance of spin-orbit interactions is investigated by comparing our nonrelativistic valence shell CI (VCI) and relativistic results obtained with our four-component program suite MOLFDIR. The six lowest excited states of the CuCl molecule, which are related to the Cu+(3d(9)4s(1))Cl-(3s(2)3p(6)) ionic configuration, are assigned. The assignments agree with earlier theoretical work. Where they can be compared, the calculated spectroscopic constants are in good agreement with the experimental data. (C) 1997 American Institute of Physics.

In this work we discuss the interaction of an adsorbate on an ionic surface taking as representative example CO on a perfect MgO(100) surface. The main goal is to investigate the different contributions to the interaction and how to model them by using a finite cluster model. To this end we use three different ab initio Hartree-Fock approaches. First, we discuss the convergence properties of the array of point charges used to simulate the Madelung potential. Next, we use large cluster models to show that there is an oscillatory behavior of the interaction energy. We show that rather large clusters are needed to avoid such oscillations. Also, we discuss how to represent these large clusters by using model potentials and compare the results with those obtained from periodic Hartree-Fock calculations. The interaction of CO on MgO is found to be weak and of electrostatic origin, with no noticeable chemical contributions.