Enhanced control of self-doping in halide perovskites for improved thermoelectric performance

Metal halide perovskites have emerged as promising photovoltaic materials, but, despite ultralow thermal conductivity, progress on developing them for thermoelectrics has been limited. Here, we report the thermoelectric properties of all-inorganic tin based perovskites with enhanced air stability. Fine tuning the thermoelectric properties of the films is achieved by self-doping through the oxidation of tin (ΙΙ) to tin (ΙV) in a thin surface-layer that transfers charge to the bulk. This separates the doping defects from the transport region, enabling enhanced electrical conductivity. We show that this arises due to a chlorine-rich surface layer that acts simultaneously as the source of free charges and a sacrificial layer protecting the bulk from oxidation. Moreover, we achieve a figure-of-merit (ZT) of 0.14 ± 0.01 when chlorine-doping and degree of the oxidation are optimised in tandem

Family Firms and Firm Performance: Evidence from Japan

Corrigendum: Nature Structural and Molecular Biology 16 (12), 1331 (2009) doi:10.1038/nsmb1209-1331bInternational audienceThioredoxins (Trxs) are oxidoreductase enzymes, present in all organisms, that catalyze the reduction of disulfide bonds in proteins. By applying a calibrated force to a substrate disulfide, the chemical mechanisms of Trx catalysis can be examined in detail at the single-molecule level. Here we use single-molecule force-clamp spectroscopy to explore the chemical evolution of Trx catalysis by probing the chemistry of eight different Trx enzymes. All Trxs show a characteristic Michaelis-Menten mechanism that is detected when the disulfide bond is stretched at low forces, but at high forces, two different chemical behaviors distinguish bacterial-origin from eukaryotic-origin Trxs. Eukaryotic-origin Trxs reduce disulfide bonds through a single-electron transfer reaction (SET), whereas bacterial-origin Trxs show both nucleophilic substitution (SN2) and SET reactions. A computational analysis of Trx structures identifies the evolution of the binding groove as an important factor controlling the chemistry of Trx catalysis

Interpreting EEG alpha activity

Exploring EEG alpha oscillations has generated considerable interest, in particular with regards to the role they play in cognitive, psychomotor, psycho-emotional and physiological aspects of human life. However, there is no clearly agreed upon definition of what constitutes ‘alpha activity’ or which of the many indices should be used to characterize it. To address these issues this review attempts to delineate EEG alpha-activity, its physical, molecular and morphological nature, and examine the following indices: (1) the individual alpha peak frequency; (2) activation magnitude, as measured by alpha amplitude suppression across the individual alpha bandwidth in response to eyes opening, and (3) alpha “auto-rhythmicity” indices: which include intra-spindle amplitude variability, spindle length and steepness. Throughout, the article offers a number of suggestions regarding the mechanism(s) of alpha activity related to inter and intra-individual variability. In addition, it provides some insights into the various psychophysiological indices of alpha activity and highlights their role in optimal functioning and behavior

Divergent profile of emerging cutaneous Leishmaniasis in subtropical Brazil: new endemic areas in the southern frontier.

Submitted by Luciane Willcox ([email protected]) on 2016-09-02T19:18:15Z No. of bitstreams: 1 Divergent Profile of Emerging Cutaneous Leishmaniasis in Subtropical Brazil.pdf: 581594 bytes, checksum: c6ba954dade22f00598aec045e140827 (MD5)Approved for entry into archive by Luciane Willcox ([email protected]) on 2016-09-02T19:37:00Z (GMT) No. of bitstreams: 1 Divergent Profile of Emerging Cutaneous Leishmaniasis in Subtropical Brazil.pdf: 581594 bytes, checksum: c6ba954dade22f00598aec045e140827 (MD5)Made available in DSpace on 2016-09-02T19:37:00Z (GMT). No. of bitstreams: 1 Divergent Profile of Emerging Cutaneous Leishmaniasis in Subtropical Brazil.pdf: 581594 bytes, checksum: c6ba954dade22f00598aec045e140827 (MD5) Previous issue date: 2013-02-14CAPES, FAPESC, PPSUS and CNPqUniversidade Federal de Santa Catarina. Departamento de Microbiologia, Imunologia e Parasitologia. Florianópolis, SC, Brasil.Universidade Federal do Rio de Janeiro. Instituto de Biofísica Carlos Chagas Filho. Rio de Janeiro, RJ, Brasil.Secretaria Estadual de Saúde de Santa Catarina. Diretoria de Vigilância Epidemiológica. Departamento de Zoonoses. Florianópolis, SC, Brasil.Universidade do Vale do Itajaí. Centro de Ciências da Saúde. Itajaí, Brasil. / Fundação Oswaldo Cruz. Instituto Carlos Chagas. Curitiba, PR, Brasil.Universidade do Vale do Itajaí. Centro de Ciências da Saúde. Itajaí, Brasil.Universidade Federal de Santa Catarina. Departamento de Microbiologia, Imunologia e Parasitologia. Florianópolis, SC, Brasil.Universidade Federal de Santa Catarina. Departamento de Microbiologia, Imunologia e Parasitologia. Florianópolis, SC, Brasil. / Fundação Oswaldo Cruz. Instituto Carlos Chagas. Curitiba, PR, Brasil.BACKGROUND: Although known to be highly endemic in the Amazon regions of Brazil, the presence of cutaneous leishmaniasis (CL) in the subtropical southern part of the country has largely been ignored. This study was conducted to demonstrate CL is emerging in the Brazilian state of Santa Catarina, as well as to characterize the epidemiological profile and Leishmania species involved. METHODOLOGY/PRINCIPAL FINDINGS: For this cross-sectional study, data from all CL cases from Santa Catarina, Brazil, reported to the Brazilian National Notifiable Diseases Information System from 2001 to 2009 were investigated. Amplification of the kDNA minicircle conserved region followed by restriction fragment length polymorphism (PCR-RFLP) was conducted to screen for Leishmania species present in patient biopsy. Overall, 542 CL cases were reported, with majority resulting from autochthonous transmission (n = 401, 73.99%) and occurring in urban zones (n = 422, 77.86%). Age, gender, zone of residence, origin of case, clinical form and case outcome were found to differ significantly by region. Imported cases were over seven times more likely to relapse (95% CI 2.56-21.09). Mapping of cases revealed new endemic areas in northeastern Santa Catarina with two species present. With the exception of three L. (Leishmania) amazonensis cases (1.20%), majority of PCR positive samples were found to be L. (Viannia) braziliensis (n = 248, 98.80%). CONCLUSIONS/SIGNIFICANCE: CL is now endemic in the state of Santa Catarina, Brazil, with case profiles varying significantly by region. L. (V.) braziliensis has been identified as the predominant species in the region