RESUMEN
There were three purposes to this research. First, we sought to test the differential role of harmonious and obsessive passion in predicting intention and habit for exercise. The second goal of this research was to test the associations between intention, habit and exercise frequency. Last, the third goal was to assess the mediation role of intention and habit in the relationship between both forms of passion and exercise frequency. The sample consisted of 284 participants (140 males, 144 females) aged 18-60 years old (M age = 29.81, SD = 9.16). Regression paths of the structural model indicated significant associations: a) harmonious passion was significantly associated with intentions and habit; b) obsessive passion was significantly associated with habit; c) intentions and habit were significantly associated with exercise frequency. The mediation model variance explained was 17% (p < .001). The total effect via harmonious and obsessive passion was ß = .57 (IC95% = .42, .73) and the total indirect effect was ß = .11 (IC95% = .02, .24). Having harmonious passion for a fitness activity appears to have the potential to increase regular physical activity among exercisers. Individuals who recognize the significance of physical exercise and participate in activities they enjoy the most can affirm the positive effects on their health from being active.
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Emociones , Intención , Masculino , Femenino , Humanos , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Motivación , Ejercicio Físico , HábitosRESUMEN
This article presents a comprehensive overview of multicomponent reactions (MCRs) that proceed via ortho-quinone methide intermediates (o-QM) generated in the reaction medium. Examples of applications involving these highly reactive intermediates in organic synthesis and biological processes (e. g., biosynthetic pathways, prodrug cleavage and electrophilic capture of biological nucleophiles) are also described. QMs are often generated by eliminative processes of phenol derivatives or by photochemical reactions, including reversible generation in photochromic substances. This class of compounds can undergo various reaction types, including nucleophilic attack at the methide carbon, with subsequent rearomatization, and react with electron-rich dienophiles in inverse-electron demand hetero-Diels-Alder reactions. Its versatile reactivity has been explored in the context of cascade reactions for the construction of several classes of substances, including complex natural products.
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Indolquinonas , Técnicas de Química Sintética , Reacción de Cicloadición , Indolquinonas/químicaRESUMEN
The present study explored the mediation role of past exercise adherence, self-reported frequency and intentions in the association between past experience and future exercise adherence. In total, 431 exercisers (female = 216; male = 215) aged 18 and 64 years, engaged in fitness activities such as group fitness classes and resistance training, were included in the analysis. Serial mediation procedures were employed to examine the direct, indirect, and total indirect effects among variables. The predictor variable and all mediators displayed a positive and significant association with future six-month adherence. Past six-month exercise adherence displayed the most significant association with future six-month adherence. The sequential indirect path from exercise experience â past six-months adherence â self-reported frequency â intentions future six-months adherence displayed a positive and significant effect (ß = .19 [CI95% = .09, .31]), presenting a partial mediation effect. Past behaviour is the most significant predictor of future adherence, and thus interventions should be based on promoting consistent exercise frequency. Professionals working in the fitness centre context can identify possible dropouts based on their past behaviour and intentions to be physically active in the future.
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Ejercicio Físico , Análisis de Mediación , Humanos , Masculino , Femenino , Intención , PredicciónRESUMEN
Most foods with probiotics claims are associated to dairy products, whose consumption is restricted to part of the population, creating a favorable scenario for the development of probiotic foods in alternative matrices. However, the development of probiotic foods in non-dairy matrices is still a technological challenge, since the foods intrinsic parameters can cause injuries to microorganisms. An alternative to protect the microbial cells in adverse environments involves encapsulation. Therefore, the objective of this study was to evaluate the influence of alginate-jaboticaba peel blend in the improvement of encapsulation efficiency, viability maintenance, and cell survival of Bifidobacterium BB12® under simulated gastrointestinal digestion and after incorporating in traditional jaboticaba jam. The particles were obtained by ion gelling technique using alginate with or without powdered jaboticaba peel. The addition of jaboticaba peel in particles improved encapsulation efficiency (> 90%) and resulted in higher cell survival in simulated gastrointestinal digestion. During storage in jam, the loss in cell viability was approximately constant: c.a. 0.5 log CFU/g/day for encapsulated cells and c.a. 1.0 log CFU/g/day for free cells. These results suggest that use of alginate and powdered jaboticaba peel blend is a promising approach to protect Bifidobacterium BB12® against adverse environments, such as non-dairy food matrices. KEY POINTS: ⢠Powdered jaboticaba peel increased the encapsulation efficiency in alginate particles. ⢠Encapsulation improved cell survival under adverse conditions. ⢠Useful approach for the development of non-conventional probiotic products. Graphical abstract.
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Bifidobacterium , Probióticos , Alginatos , Composición de Medicamentos , Viabilidad MicrobianaRESUMEN
Lutzomyia longipalpis (Diptera: Psychodidae) is the primary vector of Leishmania infantum (Kinetoplastida: Trypanosomatidae) in the Americas. Studies have been carried out to identify new alternatives for monitoring and controlling this sandfly species, particularly with the use of chemical baits. The attractiveness of odours emitted by foxes and alcohols found in some plants has already been demonstrated in laboratory tests with Lu. longipalpis. However, no studies have evaluated the responses of these insects to volatile organic compounds (VOCs) emitted by dogs. The present study was carried out to investigate the effects on Lu. longipalpis of individual and blends of VOCs identified in hair from dogs infected with L. infantum. Effects in male and female Lu. longipalpis were assessed using wind tunnel methodology. Individual compounds including octanal, nonanal, decanal and heptadecane showed capacity for activating and/or attracting male Lu. longipalpis. Only decanal and nonanal showed effects on females. The combination of octanal, decanal and heptadecane increased activation and attraction behaviour in male sandflies, as did the blend of octanal and decanal. These findings indicate that VOCs emitted by dogs may be an interesting source of new attractants of sandflies.
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Quimiotaxis , Leishmania infantum/fisiología , Psychodidae/fisiología , Compuestos Orgánicos Volátiles/metabolismo , Animales , Biomarcadores/metabolismo , Enfermedades de los Perros/parasitología , Perros , Femenino , Leishmaniasis Visceral/parasitología , Leishmaniasis Visceral/veterinaria , MasculinoRESUMEN
AIM: The study aimed to determine whether laparoscopic volume and type of training influence conversion during elective laparoscopic colorectal surgery. METHOD: An Institutional Review Board-approved prospective database was reviewed for patients who underwent colorectal resection, performed by six colorectal surgeons, for all diagnoses from 2009 to 2014. Surgeons were designated as laparoscopic- or open-trained based on formal laparoscopic colorectal surgery training, and were classified as low laparoscopic volume (LLV) (i.e. had performed < 100 laparoscopic procedures) or high laparoscopic volume (HLV) (i.e. had performed ≥ 100 laparoscopic procedures). Technique was laparoscopic, open or converted (pre-emptive or reactive). Conversion was compared among three groups: LLV, laparoscopic trained (group A); LLV, open trained (group B); and HLV, open trained (group C). RESULTS: In total, 159/567 procedures were open and 408 laparoscopic procedures were attempted. Of the 408 laparoscopic procedures, 73 were converted. Among the 567 patients [mean age: 56 ± 17 years (44% male)], the overall conversion rate was 13% (73/567), including 75% pre-emptive and 25% reactive. Conversion rates for groups A, B and C were 17.9%, 42.6% and 14.3%, respectively. Significantly higher conversion was seen in group B compared with group C (P = 0.01), but not between group A and group C (P = 0.85) or between group B and group A (P = 0.11). Converted patients were older (P < 0.001), with lower rates of proctectomy (P = 0.007), higher rates of anastomosis (P < 0.001) and higher body mass index (BMI) (P < 0.001). After adjusting for patient and surgeon factors, training type was not associated with conversion (P = 0.15). Compared with successful laparoscopy, converted patients had a significantly higher incidence of ileus (P < 0.001), length of stay (P = 0.002), time to flatus (OR = 3.21, P < 0.001) and time to solids (P < 0.001). Converted patients experienced increased morbidity. CONCLUSION: Training is not associated with conversion. Rather, HLV surgeons, regardless of training, convert less frequently than do LLV surgeons.
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Conversión a Cirugía Abierta/estadística & datos numéricos , Escolaridad , Endoscopía del Sistema Digestivo/estadística & datos numéricos , Laparoscopía/estadística & datos numéricos , Cirujanos/estadística & datos numéricos , Carga de Trabajo , Anciano , Endoscopía del Sistema Digestivo/educación , Endoscopía del Sistema Digestivo/métodos , Femenino , Humanos , Laparoscopía/educación , Laparoscopía/métodos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Cirujanos/educaciónRESUMEN
AIM: Sphincteroplasty (SP) is used to treat faecal incontinence (FI) in patients with a sphincter defect. Although sacral nerve stimulation (SNS) is used in patients, its outcome in patients with a sphincter defect has not been definitively evaluated. We compared the results of SP and SNS for FI associated with a sphincter defect. METHOD: Patients treated by SNS or SP for FI with an associated sphincter defect were retrospectively identified from an Institutional Review Board approved prospective database. Patients with ultrasound evidence of a sphincter defect were matched by age, gender and body mass index. The main outcome measure was change in the Cleveland Clinic Florida Faecal Incontinence Score (CCF-FIS). RESULTS: Twenty-six female patients with a sphincter defect were included in the study. The 13 patients in each group were similar for age, body mass index, initial CCF-FIS and the duration of follow-up. No differences were observed in parity (P = 1.00), the rate of concomitant urinary incontinence (P = 0.62) or early postoperative complications. Within-group analysis showed a significant reduction of the CCF-FIS among patients having SNS (15.9-8.4; P = 0.003) but not SP (16.9-12.9; P = 0.078). There was a trend towards a more significant improvement in CCF-FIS in the SNS than in the SP group (post-treatment CCF-FIS 8.4 vs 12.9, P = 0.06). Net improvement in CCF-FIS was not significantly different between the groups (P = 0.06). CONCLUSION: Significant improvement in CCF-FIS was observed in patients treated with SNS but not SP patients. A trend towards better results was seen with SNS.
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Canal Anal/anomalías , Terapia por Estimulación Eléctrica/métodos , Incontinencia Fecal/terapia , Procedimientos de Cirugía Plástica/métodos , Esfinterotomía/métodos , Adulto , Anciano , Canal Anal/cirugía , Bases de Datos Factuales , Incontinencia Fecal/etiología , Femenino , Humanos , Persona de Mediana Edad , Estudios Prospectivos , Calidad de Vida , Estudios Retrospectivos , Sacro/inervación , Índice de Severidad de la Enfermedad , Resultado del TratamientoRESUMEN
Drug delivery systems could be applied to locally treat cervical cancer, thus preventing the drawbacks of conventional therapy. In this study, anti-proliferative and anti-angiogenic effects of digoxin incorporated into poly(ε-caprolactone) implants were evaluated, aiming at the local treatment of cervical cancer. Implants were characterized, and the in vitro release profile of digoxin was demonstrated. Anti-proliferative and anti-angiogenic activities of digoxin were investigated by using chorioallantoic membrane and human cervix carcinoma (HeLa) cells, respectively. The chemical structure of digoxin and the semi-crystalline nature of poly(ε-caprolactone) were preserved after designing implants. The hydrophobicity of drug and polymer as well as the semi-crystalline structure provided a controlled diffusion of digoxin from implants. Digoxin released from implantable devices exhibited anti-proliferative activity against HeLa cells. The anti-angiogenic effect was also shown. Finally, implants composed of digoxin and poly(ε-caprolactone) could be applied as a therapeutic alternative to treat the early stage of cervical cancer, once they were able to locally control the release of this anti-angiogenic and anti-proliferative drug, minimizing its systemic side effects and toxicity.
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Digoxina/administración & dosificación , Sistemas de Liberación de Medicamentos , Poliésteres/química , Neoplasias del Cuello Uterino/tratamiento farmacológico , Inhibidores de la Angiogénesis/administración & dosificación , Inhibidores de la Angiogénesis/química , Inhibidores de la Angiogénesis/farmacología , Animales , Antineoplásicos/administración & dosificación , Antineoplásicos/química , Antineoplásicos/farmacología , Química Farmacéutica/métodos , Pollos , Membrana Corioalantoides , Cristalización , Digoxina/química , Digoxina/farmacología , Portadores de Fármacos/química , Implantes de Medicamentos , Liberación de Fármacos , Femenino , Células HeLa , Humanos , Interacciones Hidrofóbicas e HidrofílicasRESUMEN
Strobilurins are among the most important fungicides that are used for plant disease control worldwide. In addition to their fungicide effect, strobilurins can also improve crop physiology. Nonetheless, the impact of azoxystrobin (Az), the main marketed strobilurin, on rice physiology is still unknown. Detailed gas exchange measurements and chlorophyll a fluorescence analysis were used to examine the Az effects on the photosynthetic performance of rice plants (cultivar Metica-1) either challenged or not with Bipolaris oryzae, the causal agent of brown spot. Az impaired carbon (C) fixation in the non-inoculated plants in a manner that was not related to photochemical or biochemical limitations, but rather to decreased stomatal conductance that limited the CO2 influx into the mesophyll cells. The photosynthesis of rice plants that were not sprayed with Az dramatically decreased upon B. oryzae infection, which was chiefly governed by photochemical and biochemical limitations. The energy surplus that was caused by limited C fixation in the rice plants that were treated with Az and inoculated with B. oryzae was thermally and effectively dissipated until 72h after inoculation. In Az absence, however, this mechanism was not sufficient to prevent chronic photoinhibition to photosynthesis. The inoculated plants were not able to fully capture and exploit the collected light energy, but these constraints were greatly limited in the presence of Az. In conclusion, Az impaired the photosynthetic performance of non-infected plants by diffusive constraints, but prevented, to a greater extent, the damage to the photosynthetic apparatus during the infection process of B. oryzae.
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Ascomicetos/efectos de los fármacos , Fungicidas Industriales/farmacología , Interacciones Huésped-Patógeno/efectos de los fármacos , Metacrilatos/farmacología , Oryza/microbiología , Fotosíntesis/efectos de los fármacos , Pirimidinas/farmacología , Ascomicetos/fisiología , Oryza/fisiología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/terapia , EstrobilurinasRESUMEN
Gestational diabetes is a genetic multifactorial systemic disease that has been extensively studied. Consequently, there is a large volume of scientific literature pertaining to genes associated with gestational diabetes. The aim of this study was to characterize the main trends in scientific publications focusing on the associations between genetic polymorphisms and gestational diabetes mellitus (GDM). The related articles were extracted from Scopus using the key words "genetic polymorphism" and "gestational diabetes mellitus"; the collected data focused on various fields (medical, biochemical, etc.) and included papers published within December 2013. One hundred and eighty-three relevant articles published between 1987 and 2013 were identified; we observed a significantly increasing trend in the number of publications pertaining to GDM. A majority of the articles focused on the medical (59.9%), biochemical, and genetics and molecular biological (29.6%) aspects of the disease. The genes coding for transcription factor 7-like 2 and glucokinase (TCF7L2, 29% and GCK, 28%) were predominantly studied and reported. This study helped quantify the growth in research pertaining to GDM; researchers from the USA have published a majority of the publications related to GDM. Several candidate genes have been linked to diabetes; however, the specific gene locus responsible for GDM has not yet been identified. The results of this study could help determine the orientation of future research on genetic factors associated with GDM.
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Diabetes Gestacional/genética , Publicaciones/estadística & datos numéricos , Estudios de Casos y Controles , Diabetes Mellitus Tipo 2/genética , Femenino , Predisposición Genética a la Enfermedad , Humanos , Polimorfismo de Nucleótido Simple , EmbarazoRESUMEN
Habitat fragmentation has numerous consequences, particularly to endemic species, and has a negative impact on the genetic diversity of neglected species, leading to genetic drift. Annona crassiflora Mart. is a species that is endemic to Brazil, and its incidence in the Cerrado biome has decreased. The identification and characterization of its remaining diversity is necessary for its conservation. Our aim was to study the population structure of A. crassiflora populations from different Cerrado regions in Minas Gerais State, Brazil (Corinto, Curvelo, Carmo da Mata, Boa Esperança, and Paraguaçu) using inter-simple sequence repeat (ISSR) markers and DNA content. Nuclear DNA content was estimated by flow cytometry using 10 individuals from each population. ISSR markers were used for genotyping accessions in order to study their genetic diversity and population structures. We found considerable genetic variation among populations, with the highest variability observed in the Curvelo population. There was a significant positive correlation between DNA content and latitude (r = 0.46, P = 0. 0003). A Bayesian-based cluster analysis grouped the populations into three clusters, which followed their geographical origins. There was some level of genetic diversity and differentiation among the populations, suggesting the need for a conservation plan for this species. The ISSR markers and DNA content analysis were effective in studying the genetic diversity and population structure of A. crassiflora.
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Annona/genética , Teorema de Bayes , Brasil , Análisis por Conglomerados , Variación Genética , Genética de Población , Genotipo , Repeticiones de MicrosatéliteRESUMEN
CONTEXT: Coffee silverskin (CS), a food by-product of the coffee roasting industry, has been studied as an active ingredient for skin care products due to its high potential of antioxidant activity and low cytotoxicity. Another food waste used as ingredient with promising characteristics is obtained from Medicago sativa (MS), which antioxidants and isoflavones content is high. OBJECTIVE: The aim of this study is to evaluate and characterize a new body formulation containing two food by-products extracts. MATERIALS AND METHODS: Different parameters (such as pH, rheological behavior, color, antioxidant content and microbiological analysis) of a body cream formulation containing by-products (CSMS) and a formulation without extracts (F) were evaluated under a stability study during 180 days at different temperatures. Moreover, the in vitro cell toxicity and the in vivo skin safety and protective effects were also assessed. RESULTS: Formulation showed stable physical properties and antioxidant activity during 180 days of storage. In vitro toxicity was screened in two skin cell lines (fibroblasts and keratinocytes) and any toxicity was reported. The in vivo test carried out showed that, with respect to irritant effects, CSMS formulation can be regarded as safe for topical application and the skin hydratation improved after 30 days of its use. Also, considering the consumer acceptance, more than 90% of volunteers classified it as very pleasant. CONCLUSIONS: CSMS formulation is stable and safe for topical use as no adverse and/or side effects were observed during the application period of testing, improving skin protective properties.
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Antioxidantes/administración & dosificación , Antioxidantes/química , Extractos Vegetales/administración & dosificación , Extractos Vegetales/química , Crema para la Piel/administración & dosificación , Crema para la Piel/química , Piel/metabolismo , Administración Tópica , Adulto , Línea Celular , Química Farmacéutica/métodos , Café/química , Cosméticos/administración & dosificación , Cosméticos/química , Estabilidad de Medicamentos , Femenino , Alimentos , Humanos , Masculino , Medicago sativa/química , Persona de Mediana EdadRESUMEN
We present the first set of ab initio calculations (vertical energies and oscillator strengths) of the valence and Rydberg transitions of the anaesthetic compound halothane (CF3CHBrCl). These results are complemented by high-resolution vacuum ultraviolet photoabsorption measurements over the wavelength range 115-310 nm (10.8-4.0 eV). The spectrum reveals several new features that were not previously reported in the literature. Spin-orbit effects have been considered in the calculations for the lowest-lying states, allowing us to explain the broad nature of the 6.1 and 7.5 eV absorption bands assigned to σ*(C-Br) â nBr and σ*(C-Cl) â n(Cl) transitions. Novel absolute photoabsorption cross sections from electron scattering data were derived in the 4.0-40.0 eV range. The measured absolute photoabsorption cross sections have been used to calculate the photolysis lifetime of halothane in the upper stratosphere (20-50 km).
Asunto(s)
Electrones , Halotano/química , Teoría Cuántica , Rayos Ultravioleta , Espectroscopía de Fotoelectrones , Sincrotrones , VacioRESUMEN
The IVF outcome of a group of hyperinsulinaemic men (group B) was compared with a group of IVF males with normal insulin levels (group A). The participating females in the study groups were younger than 38 years old, had blocked Fallopian tubes and/or endometriosis, had normal insulin levels and produced five or more ova on stimulation. The male participants in both groups were normozoospermic with motility above 50% and sperm morphology between 5 and 13% normal forms (G-pattern according to Tygerberg strict criteria). The two groups did not differ statistically in terms of age or semen parameters (P = 0.39; P < 0.05).The group of men that presented with normal insulin levels had a higher fertilisation rate (79.15% versus 74.57%) and superior embryo quality on day 3 (55.77% versus 50.39%) than the group that presented with hyperinsulinaemia, but these differences were not statistically significant (P = 0.28, P = 0.40; P < 0.05). The clinical pregnancy rate of the group with normal insulin was significantly higher than that of the hyperinsulinaemic group, 57.9% versus 31.8% respectively (P = 0.03). The results suggest that hyperinsulinaemia had a negative impact on IVF outcome and patients should be advised accordingly.
Asunto(s)
Fertilización In Vitro , Fertilización , Hiperinsulinismo , Infertilidad Femenina/terapia , Insulina/sangre , Índice de Embarazo , Adulto , Blastocisto , Estudios de Casos y Controles , Empaquetamiento del ADN , Femenino , Humanos , Masculino , Persona de Mediana Edad , Embarazo , Análisis de Semen , Recuento de Espermatozoides , Motilidad Espermática , Resultado del TratamientoRESUMEN
Previous reports indicated that hyperinsulinaemic men may exhibit a higher percentage of poorly compacted DNA in their spermatozoa and less success in an IVF programme (Andrologia, 45, 2003, 18; Andrologia, 2014, doi: 10.1111/and.12227). The aim of this study was to investigate the effect of metformin (Glucophage®) and antioxidant treatment (StaminoGro®) on the semen parameters of hyperinsulinaemic men. Nineteen hyperinsulinaemic male patients were treated for 3 months with metformin alone (Group A), and fifteen patients used metformin in combination with the nutritional supplement (Group B). Combined data of the two groups (pre- and post-treatment) differ significantly regarding sperm morphology (P = 0.0003) and CMA3 (P < 0.0001) values. The improvement in sperm morphology after treatment was similar for the two respective groups (P < 0.05). The morphological normal sperm forms increased from the mean percentage of 3.9 to 5.5% and from 4.2 to 5.5% for Group A and B respectively. Where a combination of metformin and the supplement were used (Group B), the combination treatment proved to be superior in obtaining enhanced chromatin packaging quality although not statistically significant (P = 0.5929) when compared with the metformin (Group A) group. The chromatin packaging quality in Group B improved with 10% while the improvement in Group A was approximately 8.3%. Therefore, infertile hyperinsulinaemic men can benefit from metformin treatment and should be advised on the use of nutritional supplements with antioxidant properties.
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Aminoácidos/uso terapéutico , Antioxidantes/uso terapéutico , Hiperinsulinismo/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Metformina/uso terapéutico , Oligoelementos/uso terapéutico , Vitaminas/uso terapéutico , Adulto , Suplementos Dietéticos , Quimioterapia Combinada , Humanos , Masculino , Persona de Mediana Edad , Análisis de Semen , Recuento de Espermatozoides , Motilidad Espermática , Espermatozoides , Resultado del TratamientoRESUMEN
Selecting the best spermatozoa for intracytoplasmic spermatozoa injection (ICSI) has recently been a topic of great interest among embryologists. The study aimed to evaluate the relationship between the spermatozoa-hyaluronan-binding assay (HBA), routine semen analysis results and fertilisation rates as recorded during conventional ICSI therapy. Ninety-one patients undergoing conventional ICSI treatment in the Medfem Fertility Clinic in Johannesburg (South Africa) were included in the study. A total of 797 oocytes were injected of which 457 oocytes fertilised (57.3%, range 0-100%). None of the semen parameters correlated with the fertilisation rates (Table 2). HBA scores, however, revealed a highly significant association (p ≤ 0.0001) with the fertilisation rates. The HBA scores also correlated significantly with the biochemical pregnancy values (Spearman r = 0.24, P = 0.02, 95% CI 0.039-0.43); however, the HBA scores did not correlate with the clinical pregnancy rates (Spearman r = 0.14, P = 0.16, 95% CI -0.06 to 0.34). No correlation was recorded between HBA and the standard semen parameters. The study showed that HBA is significantly associated with fertilisation in conventional ICSI. The HBA scores were also significantly associated with the fertilisation rates and biochemical pregnancies.
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Ácido Hialurónico/metabolismo , Índice de Embarazo , Análisis de Semen , Inyecciones de Esperma Intracitoplasmáticas , Espermatozoides/fisiología , Femenino , Humanos , Masculino , EmbarazoRESUMEN
Coffee leaf rust (CLR), caused by Hemileia vastatrix, is a major disease affecting coffee production worldwide. In this study, an in-depth analysis of the photosynthetic performance of coffee leaves challenged or not with H. vastatrix and sprayed with either epoxiconazole (EPO) or pyraclostrobin (PYR) was performed by combining chlorophyll a fluorescence images, photosynthetic pigment pools and the activities of chitinase (CHI), ß-1,3-glucanase (GLU), peroxidase (POX) and catalase (CAT). The CLR severity was higher in the control plants, but reduced in plants sprayed with both PYR and EPO. Also, the CLR severity was reduced in plants sprayed with PYR compared with plants sprayed with EPO. Plants sprayed with either EPO or PYR showed maximal photosystem II quantum efficiency (Fv/Fm) values ranging from 0.78 to 0.80, which were quite similar to those obtained with inoculated plants (values ranging from 0.74 to 0.77). The decreases in the Fv/Fm ratio values and parallel increases in the F0 values in the inoculated plants, which were not observed in the control plants (sprayed with water) and were confirmed by images of the initial fluorescence (F0) and Fv/Fm parameters in the regions of the leaf tissue containing pustules and in the asymptomatic leaf tissue, indicated that photosynthesis was negatively impacted. When effective photosystem II quantum yield (Y(II)) values approached zero with a high photosynthetic photon flux density, high values of quantum yield of regulated energy dissipation (Y(NPQ)) in association with a high carotenoid concentration were noted in the inoculated plants sprayed either with PYR or EPO. The increased CLR severity in inoculated plants in contrast to inoculated plants sprayed with either PYR or EPO was associated with greater POX activity and a reduced photosynthetic pigment concentration. POX and CAT activities were increased in inoculated plants sprayed with either EPO or PYR when compared with control plants. CHI and GLU activities were maintained at high levels in the leaves of inoculated plants, regardless of the fungicide sprayed, indicating that CHI and GLU are less important for coffee resistance against CLR. The results of the present study clearly demonstrated that plants sprayed with either EPO or PYR showed milder CLR symptoms with adequate photosynthetic performance and optimal conditioning of their antioxidant systems.
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Antioxidantes , Carbamatos , Compuestos Epoxi , Hongos , Fotosíntesis/efectos de los fármacos , Hojas de la Planta/metabolismo , Hojas de la Planta/parasitología , Pirazoles , Triazoles , Catalasa/antagonistas & inhibidores , Quitinasas/metabolismo , Coffea , Fungicidas Industriales , Peroxidasa/metabolismo , Complejo de Proteína del Fotosistema II/efectos de los fármacos , EstrobilurinasRESUMEN
Experiments were conducted in Mato Grosso, Brazil, from 2009 to 2011 to evaluate the effects of planting date (October, November, December, and January) on soybean rust (SBR) and leaf area index (LAI) in SBR-susceptible soybean cultivars of different maturity groups (early-maturing, midseason, and late-maturing). Mean relative area under the LAI progress curve (RAULAIPC) was significantly higher (P < 0.05) for the late-maturing than early-maturing and midseason cultivars. The October planting date had significantly higher (P < 0.05) mean RAULAIPC than the December and January planting dates. Mean relative area under the SBR progress curve was significantly lower (P < 0.05) for the late-maturing than the midseason and early-maturing cultivars, and significantly higher (P < 0.05) for the December and January than the October and November planting dates. Based on the logistic population growth model, SBR severity increased over time at a significantly higher mean rate for the early-maturing than the midseason and late-maturing cultivars. It took longer for SBR to reach a certain severity level for the late-maturing cultivar planted in January than the early-maturing cultivar planted in October. This implies that fungicides would need to be applied early to the early-maturing cultivar planted in October to minimize yield loss.
RESUMEN
This study used both microscopic and biochemical analyses to investigate the possible defense responses induced by acibenzolar-S-methyl (ASM) and potassium phosphite (Phi) in mango plants inoculated with Ceratocystis fimbriata. Disease development was evaluated in the stems of inoculated mango plants and these were examined using fluorescence and light microscopy. High-performance liquid chromatography (HPLC) was used to quantify secondary metabolites in the stem sections. Spraying the plants with ASM and Phi reduced internal necrosis and disease development. The ASM and Phi induced many microscopic defense responses in the stem tissues against C. fimbriata infection. HPLC analysis revealed that the concentrations of two alkaloids (theobromine and 7-methylxanthine) and 10 phenolic compounds (catechin, epicatechin, epigallocatechin, gallic acid, myricetin, p-coumaric acid, p-hydroxybenzoic acid, phloridzin, sinapinic acid, and salicylhydroxamic acid) were higher in the stem tissues of plants sprayed with ASM or Phi than in inoculated control treatment. The concentrations of phenolic compounds were higher in the stem tissues of inoculated plants than in noninoculated plants, while the inverse was observed for alkaloids. Higher concentrations of secondary metabolites in the stem tissues were detected in the early stages of fungal infection, especially in plants treated with inducers. Taken together, the results from the present study clearly support the concept that the phenylpropanoid pathway in the stem tissues of mango plants infected by C. fimbriata can be induced by ASM and Phi.