Towards the development of fiber lasers for the 2 to 4 nanom spectral region

A growing number of applications are calling for compact laser sources operating in the mid-infrared spectral region. A review of our recent work on monolithic fiber lasers (FL) based either on the use of rare-earth fluoride fibers or on Raman gain in both fluoride and chalcogenide glass fibers is presented. Accordingly, an erbium-doped double clad fluoride glass all-FL operating in the vicinity of 3 μm is shown. In addition, we present recent results on the first demonstrations of both fluoride and chalcogenide Raman fiber lasers operating at 2.23 and 3.34 μm, respectively. It is shown that based on this approach, monolithic FLs could be developed to cover the whole 2 to 4 μm spectral band.

Wasserfreie Protonenleiter für Brennstoffzellen auf der Basis von Imidazol und Benzimidazol

Mit Hilfe von Brennstoffzellen wird eine effiziente Energieumwandlung von chemischer in elektrische Energie möglich. Die kommerziellen PEM-Brennstoffzellen benutzen Membra-nen, die zum Erreichen hoher Leitfähigkeiten eine wässrige Phase erfordern, in der der Proto-nentransport stattfindet. Somit wird die Betriebstemperatur durch den Siedepunkt des Wassers limitiert. Die verwendeten Pt-Katalysatoren zeigen bei niedrigen Temperaturen eine höhere Empfindlichkeit gegenüber CO, dass im Reformierungsprozess bei der Erzeugung von Was-serstoff entsteht. Austausch der wässrigen Phase gegen Heterozyklen, die ein zu Wasser ver-gleichbares Wasserstoffbrückennetzwerk aufbauen, in dem der Protonentransport stattfinden kann, ermöglicht eine höhere Betriebstemperatur. Durch das im Laufe des Brennstoffzellen-betriebs gebildete Wasser, können die Heterozyklen verdünnt bzw. komplett aus der Memb-ran ausgewaschen werden. Daher ist es erforderlich, die Ladungsträger an ein Polymerrück-grat zu binden, so dass sie eine hohe Beweglichkeit und Konzentration, die denen in der flüs-sigen Phase einer konventionellen Membran entsprechen, aufweisen. Diese Arbeit beschreibt die Synthese und Charakterisierung von Protonenleitern, die ohne eine flüssige Phase auskommen, da sie bereits protonische Leitfähigkeit als intrinsische Ei-genschaft zeigen. Es wurden verschiedene imidazol- bzw. benzimidazolhaltige Dimere und Polythiophene, in denen Benzimidazol in der Seitenkette über verschieden flexible Spacer mit dem Polymerrückgrat verbunden ist, synthetisiert. Die Materialien wurden in undotierten Zu-stand und nach Dotierung mit geringen Mengen Phosphorsäure umfassend charakterisiert und auf thermisches Verhalten, Stabilität und Leitfähigkeit untersucht. Die benzimidazolhaltigen Dimere weisen mit 250 °C die höchsten Zersetzungstemperaturen auf. Mit zunehmender Temperatur kann in allen Fällen eine Erhöhung der Leitfähigkeit beobachtet werden, die sich in der Arrhenius-Auftragung durch eine Gerade anpassen lässt, somit kann der Protonentrans-port durch einen Protonen-hüpfmechanismus beschrieben werden. Die höchste beobachtete Leitfähigkeit liegt im Bereich von 10-6 S/cm bei 160 °C. Durch Zusatz von Phosphorsäure kann die Leitfähigkeit z.T. um einige Größenordnungen gesteigert werden. Eine Ausnahme bilden die Polythiophene, die sowohl protonische als auch elektronische Leitfähigkeit besit-zen. Hier führt die Säure zu einer Lokalisierung der Ladungsträger, so dass die elektronische Leitfähigkeit eingeschränkt wird.

Charge generation and recombination in hybrid organic,inorganic solar cells

This thesis deals with the investigation of exciton and charge dynamics in hybrid solar cells by time-resolved optical spectroscopy. Quasi-steady-state and transient absorption spectroscopy, as well as time-resolved photoluminescence spectroscopy, were employed to study charge generation and recombination in solid-state organic dye-sensitized solar cells, where the commonly used liquid electrolyte is replaced by an organic solid hole transporter, namely 2,2′7,7′-tetrakis-(N,N-di-p-methoxyphenyl-amine)-9,9′-spirobifluorene (spiro-MeOTAD), and polymer-metal oxide bulk heterojunction solar cells, where the commonly used fullerene acceptor [6,6]-phenyl C61 butyric acid methyl ester (PCBM) is replaced by zinc oxide (ZnO) nanoparticles. By correlating the spectroscopic results with the photovoltaic performance, efficiency-limiting processes and processes leading to photocurrent generation in the investigated systems are revealed. rnIt is shown that the charge generation from several all-organic donor-π-bridge-acceptor dyes, specifically perylene monoimide derivatives, employed in solid-state dye-sensitized solar cells, is strongly dependent on the presence of a commonly used additive lithium bis(trifluoromethanesulphonyl)imide salt (Li-TFSI) at the interface. rnMoreover, it is shown that charges can not only be generated by electron injection from the excited dye into the TiO2 acceptor and subsequent regeneration of the dye cation by the hole transporter, but also by an alternative mechanism, called preceding hole transfer (or reductive quenching). Here, the excited dye is first reduced by the hole transporter and the thereby formed anion subsequently injects an electron into the titania. This additional charge generation process, which is only possible for solid hole transporters, helps to overcome injection problems. rnHowever, a severe disadvantage of solid-state dye-sensitized solar cells is re-vealed by monitoring the transient Stark effect on dye molecules at the inter-face induced by the electric field between electrons and holes. The attraction between the negative image charge present in TiO2, which is induced by the positive charge carrier in the hole transporter due to the dielectric contrast between the organic spiro-MeOTAD and inorganic titania, is sufficient to at-tract the hole back to the interface, thereby increasing recombination and suppressing the extraction of free charges.rnBy investigating the effect of different dye structures and physical properties on charge generation and recombination, design rules and guidelines for the further advancement of solid-state dye-sensitized solar cells are proposed.rnFinally, a spectroscopic study on polymer:ZnO bulk heterojunction hybrid solar cells, employing different surfactants attached to the metal oxide nanoparticles, was performed to understand the effect of surfactants upon photovoltaic behavior. By applying a parallel pool analysis on the transient absorption data, it is shown that suppressing fast recombination while simultaneously maintaining the exciton splitting efficiency by the right choice of surfactants leads to better photovoltaic performances. Suppressing the fast recombination completely, whilst maintaining the exciton splitting, could lead to a doubling of the power conversion efficiency of this type of solar cell.

Influence of Surface Roughness on Mechanical Properties of Two Computer-aided Design/Computer-aided Manufacturing (CAD/CAM) Ceramic Materials

SUMMARY The aim of this study was to evaluate the influence of surface roughness on surface hardness (Vickers; VHN), elastic modulus (EM), and flexural strength (FLS) of two computer-aided design/computer-aided manufacturing (CAD/CAM) ceramic materials. One hundred sixty-two samples of VITABLOCS Mark II (VMII) and 162 samples of IPS Empress CAD (IPS) were ground according to six standardized protocols producing decreasing surface roughnesses (n=27/group): grinding with 1) silicon carbide (SiC) paper #80, 2) SiC paper #120, 3) SiC paper #220, 4) SiC paper #320, 5) SiC paper #500, and 6) SiC paper #1000. Surface roughness (Ra/Rz) was measured with a surface roughness meter, VHN and EM with a hardness indentation device, and FLS with a three-point bending test. To test for a correlation between surface roughness (Ra/Rz) and VHN, EM, or FLS, Spearman rank correlation coefficients were calculated. The decrease in surface roughness led to an increase in VHN from (VMII/IPS; medians) 263.7/256.5 VHN to 646.8/601.5 VHN, an increase in EM from 45.4/41.0 GPa to 66.8/58.4 GPa, and an increase in FLS from 49.5/44.3 MPa to 73.0/97.2 MPa. For both ceramic materials, Spearman rank correlation coefficients showed a strong negative correlation between surface roughness (Ra/Rz) and VHN or EM and a moderate negative correlation between Ra/Rz and FLS. In conclusion, a decrease in surface roughness generally improved the mechanical properties of the CAD/CAM ceramic materials tested. However, FLS was less influenced by surface roughness than expected.

BCL2 mutation spectrum in B-cell non-Hodgkin lymphomas and patterns associated with evolution of follicular lymphoma

BCL2 is a target of somatic hypermutation in t(14;18) positive and also in a small fraction of t(14;18) negative diffuse large B-cell lymphoma (DLBCL), suggesting an aberrant role of somatic hypermutation (ASHM). To elucidate the prevalence of BCL2 mutations in lymphomas other than DLBCL, we Sanger-sequenced the hypermutable region of the BCL2 gene in a panel of 69 mature B-cell lymphomas, including Richter's syndrome DLBCL, marginal-zone lymphomas, post-transplant lymphoproliferative disorders, HIV-associated and common-variable immunodeficiency-associated DLBCL, all known to harbour ASHM-dependent mutations in other genes, as well as 16 t(14,18) negative and 21 t(14;18) positive follicular lymphomas (FLs). We also investigated the pattern of BCL2 mutations in longitudinal samples from 10 FL patients relapsing to FL or transforming to DLBCL (tFL). By direct sequencing, we found clonally represented BCL2 mutations in 2/16 (13%) of t(14;18) negative FLs, 2/16 (13%) HIV-DLBCLs, 1/9 (11%) of Richter's syndrome DLBCL, 1/17 (6%) of post-transplant lymphoproliferative disorders and 1/2 (50%) common-variable immunodeficiency-associated DLBCL. The proportion of mutated cases was significantly lower than in FLs carrying the t(14;18) translocation (15/21, 71%). However, the absence of t(14;18) by FISH or PCR and the molecular features of the mutations strongly suggest that BCL2 represents an additional target of ASHM in these entities. Analysis of the BCL2 mutation pattern in clonally related FL/FL and FL/tFL samples revealed two distinct scenarios of genomic evolution: (i) direct evolution from the antecedent FL clone, with few novel clonal mutations acquired by the tFL major clone, and (ii) evolution from a common mutated long-lived progenitor cell, which subsequently acquired distinct mutations in the FL and in the relapsed or transformed counterpart. Copyright © 2014 John Wiley & Sons, Ltd.

Impacto de mancha ojo de rana (Cercospora sojina k. Hara) sobre rendimiento y componentes industriales del grano de soja: aceite y proteína

La mezcla de fungicidas estrobilurina y triazol (E+T) se aplicó a 2 cultivares contrastantes en susceptibilidad a mancha ojo de rana (MOR) (DM3700 y DM3810) en los estadíos R3 o R3+R5; se incluyeron además 2 controles: enfermo y sano. Se avaluó incidencia y severidad de MOR, rendimiento, número de granos (NG), peso de granos (PG), aceite y proteína del grano. Se observaron distintos niveles de severidad entre tratamientos de DM3700 y ausencia de MOR en los tratamientos de DM3810. Se encontró correlación negativa entre severidad y rendimiento. En DM3700 los valores más elevados de severidad se correspondieron con rendimientos más bajos (2117 kg/ha). DM3810 exhibió rendimientos elevados y sin diferencias estadísticas entre tratamientos (3478 kg/ha). Aunque NG y PG disminuyeron en el testigo enfermo DM3700, las reducciones del NG fueron más pronunciadas. No hubo incrementos de rendimiento, NG y/o PG atribuidos a E+T en DM3810. La severidad máxima en el cultivar más susceptible no fue suficiente para disminuir significativamente aceite y proteína. MOR pudo ser controlada en el cultivar susceptible con una única aplicación de E+T en R3. El uso del cultivar resistente a MOR resultó efectivo para controlar la enfermedad y no manifestó beneficios adicionales en rendimiento debido a la aplicación de fungicidas. En este trabajo se concluyó que MOR no afectó la calidad industrial del grano.

CARACTERÍSTICAS PSICOSSOCIAIS E DE PERSONALIDADE DE ADOLESCENTES INFRATORES EM CUMPRIMENTO DE MEDIDA SOCIOEDUCATIVA

Para atingir os objetivos propostos, ou seja, levantar e descrever indicadores socioculturais de uma amostra de adolescentes em cumprimento de medida socioeducativa, e descrever características psicológicas e de personalidade dos adolescentes infratores, num estudo que pesquisou adolescentes em cumprimento de medida socioeducativa. O trabalho foi realizado em duas as etapas: na primeira, os 47 adolescentes participaram de uma entrevista semidirigida; na segunda, dez desses adolescentes foram selecionados e submetidos a um instrumento projetivo para investigação de aspectos da personalidade: o “desenho da Figura Humana” de Machower, adaptado por Van Kolck (1956; 1984). A discussão teórica dos resultados baseou-se numa abordagem psicanalítica pós-freudiana para a compreensão da adolescência tanto como fase do desenvolvimento humano como dos comportamentos antissociais. Os resultados do estudo corroboraram a teoria advinda da literatura psicológica que aborda padrões comuns no período da adolescência, fase em que ocorre um complexo de fatores individuais da maturidade biológica associados ao meio social/cultural e que, por sua vez, estabelecem relações com as instâncias psicológicas ou psíquicas do sujeito junto com as características específicas de cada indivíduo. Na busca da compreensão desses padrões comuns da amostra dos adolescentes infratores utilizados no presente estudo, foram levantados dados do perfil psicossocial, cultural e demográfico; dos aspectos psicossociais e aspectos psicodinâmicos e de características de personalidade. A título de conclusão, o estudo destacou a problemática do adolescente em conflito com a lei, associada às questões sociais, de saúde mental, além do desenvolvimento psíquico, sinalizando a necessidade de ações psicoprofiláticas voltadas para população infantil, jovem, agrupamentos familiares e para a comunidade que representa seu entorno.

Qualidade da Construção dos Vínculos entre Filhas Cuidadoras e Mães Idosas Dependentes

Este estudo teve por objetivos: - descrever as dificuldades nas relações entre as filhas-cuidadoras e suas mães idosas dependentes de cuidados, a partir de relatos das filhas; - investigar, a partir dos relatos da história familiar dessas filhas, a existência de conflitos prévios a necessidade de cuidar, relacionados à construção dos vínculos; identificar os principais desafios associados assistência ao cuidador familiar de idosos no que tange a resolução de conflitos com o idoso dependente. Método – tratou-se de um estudo qualitativo em que foram apresentados três casos clínicos de cuidadoras que haviam sido encaminhados para atendimento psicológico pela equipe multiprofissional de um Instituto de Geriatria e Gerontologia, unidade de atenção secundária da Secretaria de Estado da Saúde de S.P. Os resultados indicaram dificuldades relacionais entre ambas: cuidadoras filhas e mães idosas. As cuidadoras revelaram sobrecarga física e emocional e grande sofrimento. Todavia, a existência desses conflitos remontava às relações anteriores à atual situação de dependência; ficando bastante evidenciado, tanto pelas histórias de vida das cuidadoras, quanto pelo conteúdo trazido durante o processo terapêutico, a repetição das relações primeiras estabelecidas entre mãe-filha. O processo psicoterapêutico pôde permitir a essas cuidadoras a compreensão da necessidade em ter suas falhas ambientais supridas, na medida em que foi propiciado um ambiente favorável ao relacionamento humano. Assim, ao observarmos que ao longo do processo as pacientes apresentavam mudanças significativas, entendemos que a psicoterapia pode figurar como meio preventivo e preservação de equilíbrio psíquico.

Knock-out mutants from an En-1 mutagenized Arabidopsis thaliana population generate phenylpropanoid biosynthesis phenotypes

A collection of 8,000 Arabidopsis thaliana plants carrying 48,000 insertions of the maize transposable element En-1 has been generated. This population was used for reverse genetic analyses to identify insertions in individual gene loci. By using a PCR-based screening protocol, insertions were found in 55 genes. En-1 showed no preference for transcribed or untranscribed regions nor for a particular orientation relative to the gene of interest. In several cases, En-1 was inserted within a few kilobases upstream or downstream of the gene. En-1 was mobilized from such positions into the respective gene to cause gene disruption. Knock-out alleles of genes involved in flavonoid biosynthesis were generated. One mutant line contained an En-1 insertion in the flavonol synthase gene (FLS) and showed drastically reduced levels of kaempferol. Allelism tests with other lines containing En-1 insertions in the flavanone 3-hydroxylase gene (F3H) demonstrated that TRANSPARENT TESTA 6 (TT6) encodes flavanone 3-hydroxylase. The f3h and fls null mutants complete the set of A. thaliana lines defective in early steps of the flavonoid pathway. These experiments demonstrate the efficiency of the screening method and gene disruption strategy used for assigning functions to genes defined only by sequence.

A Fiberless Seed Mutation in Cotton Is Associated with Lack of Fiber Cell Initiation in Ovule Epidermis and Alterations in Sucrose Synthase Expression and Carbon Partitioning in Developing Seeds1

Fiber cell initiation in the epidermal cells of cotton (Gossypium hirsutum L.) ovules represents a unique example of trichome development in higher plants. Little is known about the molecular and metabolic mechanisms controlling this process. Here we report a comparative analysis of a fiberless seed (fls) mutant (lacking fibers) and a normal (FLS) mutant to better understand the initial cytological events in fiber development and to analyze the metabolic changes that are associated with the loss of a major sink for sucrose during cellulose biosynthesis in the mutant seeds. On the day of anthesis (0 DAA), the mutant ovular epidermal cells lacked the typical bud-like projections that are seen in FLS ovules and are required for commitment to the fiber development pathway. Cell-specific gene expression analyses at 0 DAA showed that sucrose synthase (SuSy) RNA and protein were undetectable in fls ovules but were in abundant, steady-state levels in initiating fiber cells of the FLS ovules. Tissue-level analyses of developing seeds 15 to 35 DAA revealed an altered temporal pattern of SuSy expression in the mutant relative to the normal genotype. Whether the altered programming of SuSy expression is the cause or the result of the mutation is unknown. The developing seeds of the fls mutant have also shown several correlated changes that represent altered carbon partitioning in seed coats and cotyledons as compared with the FLS genotype.

Eserzicio logico sugli errori d'ideologia e zoologia ossia arte di trar profitto dai cattivi libri dissertazione /

Mode of access: Internet.

Hourly compensation costs for production workers : 40 manufacturing industries ... countries, 1975 and ... /

Latest issue consulted: 1983-93.

CARACTERÍSTICAS PSICOSSOCIAIS E DE PERSONALIDADE DE ADOLESCENTES INFRATORES EM CUMPRIMENTO DE MEDIDA SOCIOEDUCATIVA

Para atingir os objetivos propostos, ou seja, levantar e descrever indicadores socioculturais de uma amostra de adolescentes em cumprimento de medida socioeducativa, e descrever características psicológicas e de personalidade dos adolescentes infratores, num estudo que pesquisou adolescentes em cumprimento de medida socioeducativa. O trabalho foi realizado em duas as etapas: na primeira, os 47 adolescentes participaram de uma entrevista semidirigida; na segunda, dez desses adolescentes foram selecionados e submetidos a um instrumento projetivo para investigação de aspectos da personalidade: o “desenho da Figura Humana” de Machower, adaptado por Van Kolck (1956; 1984). A discussão teórica dos resultados baseou-se numa abordagem psicanalítica pós-freudiana para a compreensão da adolescência tanto como fase do desenvolvimento humano como dos comportamentos antissociais. Os resultados do estudo corroboraram a teoria advinda da literatura psicológica que aborda padrões comuns no período da adolescência, fase em que ocorre um complexo de fatores individuais da maturidade biológica associados ao meio social/cultural e que, por sua vez, estabelecem relações com as instâncias psicológicas ou psíquicas do sujeito junto com as características específicas de cada indivíduo. Na busca da compreensão desses padrões comuns da amostra dos adolescentes infratores utilizados no presente estudo, foram levantados dados do perfil psicossocial, cultural e demográfico; dos aspectos psicossociais e aspectos psicodinâmicos e de características de personalidade. A título de conclusão, o estudo destacou a problemática do adolescente em conflito com a lei, associada às questões sociais, de saúde mental, além do desenvolvimento psíquico, sinalizando a necessidade de ações psicoprofiláticas voltadas para população infantil, jovem, agrupamentos familiares e para a comunidade que representa seu entorno.

Qualidade da Construção dos Vínculos entre Filhas Cuidadoras e Mães Idosas Dependentes

Este estudo teve por objetivos: - descrever as dificuldades nas relações entre as filhas-cuidadoras e suas mães idosas dependentes de cuidados, a partir de relatos das filhas; - investigar, a partir dos relatos da história familiar dessas filhas, a existência de conflitos prévios a necessidade de cuidar, relacionados à construção dos vínculos; identificar os principais desafios associados assistência ao cuidador familiar de idosos no que tange a resolução de conflitos com o idoso dependente. Método – tratou-se de um estudo qualitativo em que foram apresentados três casos clínicos de cuidadoras que haviam sido encaminhados para atendimento psicológico pela equipe multiprofissional de um Instituto de Geriatria e Gerontologia, unidade de atenção secundária da Secretaria de Estado da Saúde de S.P. Os resultados indicaram dificuldades relacionais entre ambas: cuidadoras filhas e mães idosas. As cuidadoras revelaram sobrecarga física e emocional e grande sofrimento. Todavia, a existência desses conflitos remontava às relações anteriores à atual situação de dependência; ficando bastante evidenciado, tanto pelas histórias de vida das cuidadoras, quanto pelo conteúdo trazido durante o processo terapêutico, a repetição das relações primeiras estabelecidas entre mãe-filha. O processo psicoterapêutico pôde permitir a essas cuidadoras a compreensão da necessidade em ter suas falhas ambientais supridas, na medida em que foi propiciado um ambiente favorável ao relacionamento humano. Assim, ao observarmos que ao longo do processo as pacientes apresentavam mudanças significativas, entendemos que a psicoterapia pode figurar como meio preventivo e preservação de equilíbrio psíquico.

Effects of yellow filters on visual acuity, contrast sensitivity and reading under conditions of forward light scatter

Background Yellow filters are sometimes recommended to people with low vision. Our aim was investigate the effects of three commercial yellow filters on visual acuity and contrast sensitivity (with and without glare) and reading (without glare) under conditions of forward light scatter (FLS). Method Fifty-five healthy subjects were assessed with Corning Photochromic Filters (CPFs) 450, 511 and 527 and a filter producing FLS. The effects on log MAR visual acuity, Pelli–Robson contrast sensitivity with and without glare, and reading (measured with MNRead charts) without glare were determined. Results Statistically significant differences were found between the overall effect of glare and between CPFs for visual acuity and contrast sensitivity. A gradual decline in visual acuity, contrast sensitivity and reading with increasing CPF absorption was noted. Conclusion Effects of CPF450, 511, 527 on visual acuity, contrast sensitivity and reading under conditions of FLS were negative but not clinically significant.