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Enzymes' uncharacterised side activities can have significant effects on reaction products and yields. Hence, their identification and characterisation are crucial for the development of successful reaction systems. Here, we report the presence of feruloyl esterase activity in CtXyn5A from Acetivibrio thermocellus, besides its well-known arabinoxylanase activity, for the first time. Activity analysis of enzyme variants mutated in the catalytic nucleophile, Glu279, confirmed removal of all activity for E279A and E279L, and increased esterase activity while removing xylanase activity for E279S, thus allowing the proposal that both reaction types are catalysed in the same active site in two subsequential steps. The ferulic acid substituent is cleaved off first, followed by hydrolysis of the xylan backbone. The esterase activity on complex carbohydrates was found to be higher than that of a designated ferulic acid esterase (E-FAERU). Therefore, we conclude that the enzyme exhibits a dual function rather than an esterase side activity.
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Hidrolasas de Éster Carboxílico , Xilanos , Dominio Catalítico , Hidrolasas de Éster Carboxílico/química , Especificidad por SustratoRESUMEN
The current study examined the role of implicitly measured associations (henceforth referred to as associations) between math and anxiety in adolescents' math anxiety. Previous research has shown that associations predicted behavior independent of explicit measures. In this study, it was investigated whether math-anxiety associations would be related to math anxiety and whether they predicted math behavior as well as state math anxiety independent of explicitly measured math anxiety. In addition, the domain specificity of math-anxiety associations for predicting math behavior was investigated. Adolescents' anxiety associations and self-reported anxiety were assessed for three domains: math anxiety, foreign language (English) anxiety, and trait anxiety. A sample of 189 secondary school students performed three single-target implicit association tests, performed a math problem solving task, and filled out questionnaires. Overall, adolescents showed stronger math-anxiety associations in comparison with math-calmness associations. In contrast to our hypotheses, math-anxiety associations were not related and did not uniquely or specifically predict math behavior and state math anxiety. Explicit anxiety measures demonstrated specificity in predicting math and English grades as well as state math anxiety. The innovative aspects of this study are the investigation of implicitly measured math-anxiety associations and the relation to math anxiety and math behavior. Further research is needed to develop tasks that are better able to capture the most relevant math-threat associations and to investigate which math behavior might be most strongly influenced by these associations.
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Ansiedad/psicología , Matemática , Solución de Problemas , Adolescente , Femenino , Humanos , Masculino , AutoinformeRESUMEN
Xylan has a main chain consisting of ß-1,4-linked xylose residues with diverse substituents. Endoxylanases cleave the xylan chain at cleavage sites determined by the substitution pattern and thus give different oligosaccharide product patterns. Most known endoxylanases belong to glycoside hydrolase (GH) families 10 and 11. These enzymes work well on unsubstituted xylan but accept substituents in certain subsites. The GH11 enzymes are more restricted by substituents, but on the other hand, they are normally more active than the GH10 enzymes on insoluble substrates, because of their smaller size. GH5 endoxylanases accept arabinose substituents in several subsites and require it in the - 1 subsite. This specificity makes the GH5 endoxylanases very useful for degradation of highly arabinose-substituted xylans and for the selective production of arabinoxylooligosaccharides, without formation of unsubstituted xylooligosaccharides. The GH30 endoxylanases have a related type of specificity in that they require a uronic acid substituent in the - 2 subsite, which makes them very useful for the production of uronic acid substituted oligosaccharides. The ability of dietary xylooligosaccharides to function as prebiotics in humans is governed by their substitution patterns. Endoxylanases are thus excellent tools to tailor prebiotic oligosaccharides to stimulate various types of intestinal bacteria and to cause fermentation in different parts of the gastrointestinal tract. Continuously increasing knowledge on the function of the gut microbiota and discoveries of novel endoxylanases increase the possibilities to achieve health-promoting effects.
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Endo-1,4-beta Xilanasas/metabolismo , Glucuronatos/metabolismo , Oligosacáridos/metabolismo , Prebióticos/microbiología , Arabinosa/metabolismo , Microbioma Gastrointestinal/fisiología , Tracto Gastrointestinal/metabolismo , Tracto Gastrointestinal/microbiología , Humanos , Especificidad por Sustrato , Ácidos Urónicos/metabolismo , Xilanos/metabolismoRESUMEN
PURPOSE: The purpose of the study was to evaluate the characteristics of sebaceous gland carcinoma (SGC) of the ocular adnexae, which is due to a high variability in clinical, histological and immunohistochemical characteristics often challenging to diagnose. METHODS: Records of six patients with SGC were reviewed, who underwent surgical excision and who were histologically diagnosed with SGC. For comparison, there were specimens from four patients with basal cell carcinoma (BCC) and four patients with squamous cell carcinoma (SCC). Histological and immunohistochemical analysis included stains for HE, cytokeratins (CKpan, Cam5.2), epithelial membrane antigen (EMA), androgen receptor (AR441), perforin and adipophilin. RESULTS: SGC's were located in the upper (n = 2) or lower (n = 4) eyelid and were associated with various presenting clinical signs including chalazion-like lesions with pyogenic granuloma (n = 1), papillomatous conjunctival tumors (n = 3), a hyperkeratotic exophytic neoplasm (n = 1) and an ulcerating crusted lesion resembling chronic blepharitis (n = 1). The treatment was tumor resection, followed (if necessary) by adjuvant therapy with topical Mitomycin C (n = 2). Histologic characteristics included basophilic pleomorphic cells with vacuolated cytoplasm, prominent nucleoli, mitotic figures and in some cases pagetoid spread (n = 2). CKpan, EMA and Cam5.2 showed strong positive immunoreactivity in all specimens (SGC, BCC, SCC). Perforin immunostaining showed a varying, but overall weak, non-specific cytoplasmatic staining reaction in all lesions. AR441 positivity was noted with variable intensity in almost all lesions and in particular in pagetoid spread in contrast to non-tumor cells. Adipophilin showed an annular staining of lipid granules in immature sebaceous cells in SGC in contrast to a more granular staining pattern in BCC and SCC. CONCLUSION: SGCs display a variety of clinical signs and may mimic many other lesions. Tumor resection, followed by histological and immunohistochemical analysis, leads to the diagnosis and initiation of the proper treatment regimen. Herein, immunohistochemistry showed an unequivocal profile in SGC and did not allow for an exact differentiation from BCC and SCC by immunohistochemical means only. An extended evaluation of HE stains remains essential. However, immunohistochemistry can make relevant contributions to the diagnosis of SGC, especially in cases of inconclusive histology, by positive staining for adipophilin in immature sebaceous cells or by AR441 labeling in cases of pagetoid spread.
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Adenocarcinoma Sebáceo/patología , Biomarcadores de Tumor/metabolismo , Neoplasias de los Párpados/patología , Estadificación de Neoplasias , Neoplasias de las Glándulas Sebáceas/patología , Glándulas Sebáceas/patología , Adenocarcinoma Sebáceo/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de los Párpados/metabolismo , Femenino , Estudios de Seguimiento , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Perilipina-2/metabolismo , Estudios Retrospectivos , Neoplasias de las Glándulas Sebáceas/metabolismoRESUMEN
Aims. Repetitive brief ischemia and reperfusion (I/R) is associated with left ventricular dysfunction during development of ischemic cardiomyopathy. We investigated the role of zinc-donor proteins metallothionein MT1 and MT2 in a closed-chest murine model of I/R. Methods. Daily 15-minute LAD-occlusion was performed for 1, 3, and 7 days in SV129 (WT)- and MT1/2 knockout (MT(-/-))-mice (n = 8-10/group). Hearts were examined with M-mode echocardiography and processed for histological and mRNA studies. Results. Expression of MT1/2 mRNA was transiently induced during repetitive I/R in WT-mice, accompanied by a transient inflammation, leading to interstitial fibrosis with left ventricular dysfunction without infarction. In contrast, MT(-/-)-hearts presented with enhanced apoptosis and small infarctions leading to impaired global and regional pump function. Molecular analysis revealed maladaptation of myosin heavy chain isoforms and antioxidative enzymes in MT1/2(-/-)-hearts. Despite their postponed chemokine induction we found a higher total neutrophil density and macrophage infiltration in small infarctions in MT(-/-)-hearts. Subsequently, higher expression of osteopontin 1 and tenascin C was associated with increased myofibroblast density resulting in predominately nonreversible fibrosis and adverse remodeling in MT1/2(-/-)-hearts. Conclusion. Cardioprotective effects of MT1/2 seem to be exerted via modulation of contractile elements, antioxidative enzymes, inflammatory response, and myocardial remodeling.
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Cardiomiopatías/metabolismo , Metalotioneína/metabolismo , Infarto del Miocardio/inmunología , Infarto del Miocardio/metabolismo , Isquemia Miocárdica/metabolismo , Daño por Reperfusión Miocárdica/metabolismo , Animales , Apoptosis/genética , Apoptosis/fisiología , Cardiomiopatías/genética , Cardiomiopatías/inmunología , Modelos Animales de Enfermedad , Ecocardiografía , Metalotioneína/genética , Ratones , Ratones Noqueados , Infarto del Miocardio/genética , Isquemia Miocárdica/inmunología , Daño por Reperfusión Miocárdica/genética , Daño por Reperfusión Miocárdica/inmunología , Osteopontina/metabolismo , Tenascina/metabolismoRESUMEN
Total body irradiation (TBI) remains an important component in many conditioning regimens before allogeneic hematopoietic stem cell transplantation (allo-HSCT). Because of its frequent toxicity, patient selection is crucial, making it of interest to identify factors improving engraftment. In this retrospective single center analysis, the characteristics of 48 adult such patients were studied. Mean overall survival (OS) was 22.2 months after allo-HSCT. Interestingly, people with an interval ≥3 days between TBI completion and allo-HSCT showed improved OS, when compared to a shorter interval (p = 0.10). Peripheral blood kinetics after successful engraftment also differed, with a longer interval resulting in a higher platelet count and lower leukocyte and neutrophil (p < 0.05) count. These data suggest that the exact timing of TBI before allo-HSCT might directly impact a patient's survival and could help single out those at higher risk of graft failure who might benefit from an altered conditioning regimen.
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Enfermedad Injerto contra Huésped , Trasplante de Células Madre Hematopoyéticas , Leucemia Mieloide Aguda , Adulto , Humanos , Estudios Retrospectivos , Irradiación Corporal Total , Cinética , Trasplante de Células Madre Hematopoyéticas/métodos , Leucemia Mieloide Aguda/complicaciones , Acondicionamiento Pretrasplante/métodos , Enfermedad Injerto contra Huésped/etiologíaRESUMEN
The success of establishing bioeconomies replacing current economies based on fossil resources largely depends on our ability to degrade recalcitrant lignocellulosic biomass. This study explores the potential of employing various enzymes acting synergistically on previously pretreated agricultural side streams (corn bran, oat hull, soluble and insoluble oat bran). Degrees of synergy (oligosaccharide yield obtained with the enzyme combination divided by the sum of yields obtained with individual enzymes) of up to 88 were obtained. Combinations of a ferulic acid esterase and xylanases resulted in synergy on all substrates, while a laccase and xylanases only acted synergistically on the more recalcitrant substrates. Synergy between different xylanases (glycoside hydrolase (GH) families 5 and 11) was observed particularly on oat hulls, producing a yield of 57%. The synergistic ability of the enzymes was found to be partly due to the increased enzyme stability when in combination with the substrates.
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Lacasa , Lignina , Hidrolasas de Éster Carboxílico , Economía , Endo-1,4-beta Xilanasas , OligosacáridosRESUMEN
BACKGROUND: Appraisals of control and value are proposed as proximal antecedents of achievement emotions, which, in turn, predict achievement. Relatively few studies have investigated how control and value may interact to determine achievement emotions, or subsequent achievement mediated by emotions. AIM: To examine whether control, value, and their interaction predicted mathematics test score directly, and indirectly, mediated by three salient achievement emotions: enjoyment, boredom, and anxiety. METHOD: Data were collected from 1,298 primary schoolchildren. Participants completed self-report measures of control, value (i.e., intrinsic, attainment, and utility), and achievement emotions (i.e., enjoyment, boredom, and anxiety), in the context of mathematics. Participants then undertook a curriculum-based mathematics test in class. RESULTS: Higher control and value were related to a higher mathematics test score directly, and indirectly, mediated via higher enjoyment and lower anxiety. The interaction of control and intrinsic value predicted mathematics test score directly, and indirectly, mediated via enjoyment. CONCLUSION: Intrinsic value amplified the direct positive relation between control and mathematics test score. Intrinsic value also protected mathematics test scores at lower levels of control indirectly, through higher enjoyment. Helping students to maximize control and value will be beneficial for their learning experience and outcomes.
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Logro , Emociones , Niño , Humanos , Matemática , Instituciones Académicas , EstudiantesRESUMEN
Oat hulls are an excellent dietary fibre source for food supplements due to their rich lignocellulose composition as well as their great abundance as low-value agricultural side stream. For the production of white fibre supplements, a mild, but effective bleaching of the hulls is required. Chemical bleaching with hydrogen peroxide and sodium hydroxide was here found to be a suitable method increasing the CIE L* value (corresponds to a lightness value) above 85. The developed method is mild, retaining the hull's chemical composition. Only a minor decrease in coniferaldehyde structures upon bleaching was detected. Colour and chemical variabilities of oat hulls from different growth seasons did not influence the required bleaching conditions to achieve the desired optical properties. The inclusion of biochemical bleaching steps utilizing the xylanase Pentopan Mono BG, the laccase NS51003 and sonication was industrially not feasible as they could not reduce the required amount of subsequently applied bleaching chemicals significantly.
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Identifying the earliest somatic changes in prostate cancer can give important insights into tumor evolution and aids in stratifying high- from low-risk disease. We integrated whole genome, transcriptome and methylome analysis of early-onset prostate cancers (diagnosis ≤55 years). Characterization across 292 prostate cancer genomes revealed age-related genomic alterations and a clock-like enzymatic-driven mutational process contributing to the earliest mutations in prostate cancer patients. Our integrative analysis identified four molecular subgroups, including a particularly aggressive subgroup with recurrent duplications associated with increased expression of ESRP1, which we validate in 12,000 tissue microarray tumors. Finally, we combined the patterns of molecular co-occurrence and risk-based subgroup information to deconvolve the molecular and clinical trajectories of prostate cancer from single patient samples.
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Biomarcadores de Tumor/genética , Metilación de ADN , Regulación Neoplásica de la Expresión Génica , Neoplasias de la Próstata/genética , Transcriptoma , Adulto , Biomarcadores de Tumor/metabolismo , Evolución Molecular , Humanos , Masculino , Persona de Mediana Edad , Mutación , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Factores de Riesgo , Secuenciación Completa del Genoma/métodosRESUMEN
This study focused on the use of math in everyday life (the propensity to recognize and solve quantitative issues in real life situations). Data from a Dutch nation-wide research on math among adults (N = 521) were used to investigate the question whether math anxiety and perceived math competence mediated the relationship between math skills and use of math in everyday life, taken gender differences into account. Results showed that women reported higher math anxiety, lower perceived math competence, and lower use of math in everyday life, compared to men. Women's skills were estimated at a lower level than men's. For both women and men, higher skills were associated with higher perceived math competence, which in turn was associated with more use of math in everyday life. Only for women, math anxiety also mediated the relation between math skills and use of math in everyday life.
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Much controversy surrounds questions about whether humans have an aversion to inequity and how a commitment to equality might play a role in cooperation and other aspects of social interactions. Examining the social decisions of children with autism spectrum disorders provides a fascinating opportunity to explore these issues. Specifically, we evaluated the possibility that children with autism spectrum disorders may be less likely than typically developing children to show a prioritisation of equality. A total of 69 typically developing (mean age 11;6 years) and 57 cognitively able children with autism spectrum disorders (mean age 11;7 years) played a social decision game in which the equality option was pitted against alternatives that varied in instrumental outcomes. Results showed that both groups were more likely to choose the equality option when there was no cost to the self. However, even though children with autism spectrum disorders appeared to view equality as preferable to causing explicit harm to others, they departed from an equality stance when there was an opportunity to increase instrumental gain without any obvious harm to the self or the other. Typically developing children, in contrast, showed similar prioritisation of equality across these contexts. Future research needs to address the question of how differences in the commitment to equality affect children's social behaviour and relationships in daily life.