Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Oecologia ; 186(1): 185-194, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29164371

RESUMO

Although most studies of mutualisms focus on a single partner at a time, host species often associate with multiple mutualist partners simultaneously. Because of potential interactions between mutualists, only studying a single type of mutualism could lead to a biased perspective of mutualism benefit and how mutualisms may scale-up to affect communities. The legume Chamaecrista fasciculata engages in a resource mutualism with nitrogen-fixing rhizobia and also forms symbiotic interactions with ants by providing nectar in exchange for defense against herbivores. Although they provide very different benefits to the plant, both mutualists receive carbon resources from the plant. As a result, these two mutualists are likely to interact, potentially competing for carbon resources or mutually benefitting each other via their positive effects on plant hosts. In a full-factorial field experiment, we explored how rhizobia and ants influence one another, C. fasciculata fitness, and the associated arthropod community. Ants reduced plant allocation to rhizobia, but ants also increased rhizobia contamination of uninoculated plants, suggesting that ants may disperse rhizobia. In turn, rhizobia increased ant abundances, with ants preferentially tending plants with rhizobia. Chamaecrista fasciculata received substantial fitness benefits from rhizobia; in contrast, associating with ants reduced fitness. Additionally, the mutualists interacted to influence the abundance of other arthropods found on the plants. Rhizobia increased arthropod abundances, likely because more nitrogen-rich leaf tissue was more attractive to arthropod herbivores, but ants negated these increases. As these results illustrate, multiple mutualists may interact, influencing each other's abundance and the abundance of other community members.


Assuntos
Formigas , Artrópodes , Chamaecrista , Rhizobium , Animais , Simbiose
3.
Front Sociol ; 9: 1368104, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38659715

RESUMO

Introduction: This paper explores older adults' perceptions on sexuality and affectivity in Chile, according to class and sex. Methods: The study is based on computer-assisted telephonic interviews with people aged 60 and over, men and women (n = 481). Data were analyzed using chi-squared tests and binary logistic regressions. Results and discussion: Maintaining an active sex life is important for older adults of both sexes, contradicting the commonsense view according to which the relevance allocated to sex decreases significantly with age. However, the data show significant differences in perceptions by sex, suggesting that gendered conceptions regarding sexuality are influential along the entire life cycle. There are also relevant differences according to class, revealing the inequalities present in the expression of sexuality in Chile.

4.
Int J Sex Health ; 36(1): 46-58, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38600899

RESUMO

This article analyzes some aspects of Chilean young people's (aged 15-29) sex life according to sex and socioeconomic background. Using data from the Tenth National Youth Survey, descriptive and inferential analyses were carried out to test possible differences in sexual practices according to these variables. Results show that young Chileans are increasingly diversifying sexual practices. Differences in age at the first sexual relationship between men and women are also becoming less clear; likewise, differences found by socioeconomic background were also weak, suggesting that some practices are common across different groups of youth. The most significant differences found concern certain practices (oral and anal sex), the number of sexual partners men and women have, and the type of relationship (romantic partner, friend, acquaintance) in which sexual encounters take place. We conclude that young people's sexual practices are increasingly being oriented toward self-exploration and personal satisfaction, and less toward the (traditional) goal of forming a family. Nonetheless, the existence of a "double standard" regarding sexual morals can still account for contrasting behaviors according to sex, suggesting the persistence of a gendered normativity. Also, sexual exploration often occurs without adequate information, reducing youngsters' ability to reduce risks or prevent undesired consequences.

5.
J Am Heart Assoc ; 13(17): e032901, 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39190595

RESUMO

BACKGROUND: Cerebrovascular events remain one of the most devastating complications of transcatheter aortic valve implantation (TAVI). Data from real-world contemporary cohorts on longitudinal trends and outcomes remain limited. The aim of this study was to assess incidence, temporal trends, predictors, and outcomes of cerebrovascular events following transfemoral TAVI. METHODS AND RESULTS: The CENTER2 (Cerebrovascular Events in Patients Undergoing Transcatheter Aortic Valve Implantation With Balloon-Expandable Valves Versus Self-Expandable Valves 2) study includes patients undergoing TAVI between 2007 and 2022. The database contains pooled patient-level data from 10 clinical studies. A total of 24 305 patients underwent transfemoral TAVI (mean age 81.5±6.7 years, 56% women, median Society of Thoracic Surgeon Predicted Risk of Mortality 4.9% [3.1%-8.5%]). Of these patients, 2.2% (n=534) experienced stroke in the first 30 days after TAVI, and 40 (0.4%) had a transient ischemic attack. Stroke rates remained stable during the treatment period (2007-2010: 2.1%, 2011-2014: 2.5%, 2015-2018: 2.1%, 2019-2022: 2.1%; Ptrend=0.28). Moreover, 30-day cerebrovascular event rates were similar across Society of Thoracic Surgeon Predicted Risk of Mortality risk categories: 2.1% in low-risk, 2.6% in intermediate-risk, and 2.5% in high-risk patients (P=0.21). Mortality was higher in patients with 30-day stroke than without at 30 days (20.3% versus 4.7%; odds ratio, 5.1 [95% CI, 4.1-6.5]; P<0.001) and at 1 year (44.1% versus 15.0%; hazard ratio, 3.5 [95% CI, 3.0-4.2]; P<0.001). One-year mortality rates for stroke did not decline over time (2007-2010: 46.9%, 2011-2014: 46.0%, 2015-2018: 43.0%, 2019-2022: 39.1%; Ptrend=0.32). At 1 year, 7.0% of patients undergoing TAVI had a stroke. CONCLUSIONS: In 24 305 patients who underwent transfemoral TAVI, 30-day cerebrovascular event incidence remained ≈ 2.2% between 2007 and 2022. Thirty-day stroke rates were similar throughout Society of Thoracic Surgeon Predicted Risk of Mortality risk categories. Mortality rates after stroke remain high. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03588247.


Assuntos
Estenose da Valva Aórtica , Substituição da Valva Aórtica Transcateter , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/cirurgia , Estenose da Valva Aórtica/mortalidade , Artéria Femoral , Incidência , Ataque Isquêmico Transitório/epidemiologia , Ataque Isquêmico Transitório/etiologia , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/mortalidade , Complicações Pós-Operatórias/etiologia , Medição de Risco/métodos , Fatores de Risco , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia , Fatores de Tempo , Substituição da Valva Aórtica Transcateter/efeitos adversos , Substituição da Valva Aórtica Transcateter/mortalidade , Resultado do Tratamento
6.
Sci Data ; 10(1): 164, 2023 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-36959253

RESUMO

Supervised analysis using spectral data requires a well-informed characterisation of the response variables and abundant spectral data points. The presented hyperspectral dataset comes from five sets of geometallurgical samples, each characterised by different methods. To provide the spectral data, all mineral samples were scanned with SPECIM VNIR and SWIR hyperspectral cameras. For each subset the following data are provided 1) hyperspectral reflectance images in the VNIR spectral range (400-1000 nm wavelength); 2) hyperspectral reflectance images in the SWIR spectral range (900-2500 nm wavelength); 3) hyperspectral reflectance images in the VNIR-SWIR range (merged to SWIR spatial resolution); 4) RGB images constructed from hyperspectral data using a Bilateral Filter based sensor fusion method; 5) response variables representing mineral sample characterisation results, provided as training and validation data. This dataset is intended for use in general regression and classification research and experiments. All subsets were validated using machine learning models with satisfactory results.

7.
Cardiol J ; 29(2): 216-227, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-32329041

RESUMO

BACKGROUND: Heart failure (HF) with preserved ejection fraction (HFpEF) and monoclonal gammopathy of uncertain significance (MGUS) are two entities that share pathophysiological mechanisms. The aim herein, was to assess the prevalence of MGUS in patients with HFpEF and no left ventricular (LV) hypertrophy, as well as its association with a pre-specified clinical endpoint at 12 months. METHODS: The present study prospectively enrolled 69 patients admitted with HF, with ejection fraction ≥ 50%, and LV wall thickness < 12 mm. All patients were screened for MGUS. Clinical events were determined over a 12 month follow-up. The pre-specified composite clinical endpoint was readmission for HF or death. RESULTS: The prevalence of MGUS in this population was 13%. There were no differences in the incidence of the composite clinical endpoint between patients with and without MGUS. Multivariate analysis showed that treatment with angiotensin converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) was associated with fewer clinical events (HR: 0.153, 95% CI: 0.037-0.622, p = 0.009) and indicated a trend to lower risk of readmission for HF and death. Beta-blockers were associated with lower rates of the composite clinical endpoint (HR: 0.192, 95% CI: 0.05-0.736, p = 0.016), readmission for HF (HR: 0.272, 95% CI: 0.087-0.851, p = 0.025) and indicated a trend to lower mortality. Moreover, potassium serum levels > 5 mEq/L were associated with higher rates of the composite endpoint (HR: 6.074, 95% CI: 1.6-22.65, p = 0.007). CONCLUSIONS: The prevalence of MGUS in patients with HFpEF without hypertrophy was 3-fold that of the general population. There was no significant correlation between clinical outcomes and the presence of MGUS. Beta-blockers and ACEIs/ARBs reduced the composite of mortality and readmissions for HF in HFpEF patients. Hyperpotassemia was related to worse prognosis.


Assuntos
Insuficiência Cardíaca , Paraproteinemias , Antagonistas Adrenérgicos beta/uso terapêutico , Antagonistas de Receptores de Angiotensina/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/epidemiologia , Humanos , Hipertrofia/tratamento farmacológico , Paraproteinemias/tratamento farmacológico , Prevalência , Prognóstico , Estudos Prospectivos , Volume Sistólico/fisiologia , Função Ventricular Esquerda/fisiologia
8.
Am J Cardiol ; 162: 31-40, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34903344

RESUMO

Currently, both drug-eluting stents (DES) and drug-eluting balloons are recommended in patients with in-stent restenosis (ISR) of metallic stents. However, the clinical results of repeated interventions in patients with restenosis of bioresorbable vascular scaffolds (BVS) remain unsettled. We sought to assess the results of interventions in patients with BVS-ISR as compared with those obtained in patients with ISR of DES and bare-metal stents (BMS). Restenosis Intrastent: Treatment of Bioresorbable Vascular Scaffolds Restenosis (RIBS VII) is a prospective multicenter study (23 Spanish sites) that included 117 consecutive patients treated for BVS-ISR. Inclusion/exclusion criteria were similar to those of previous RIBS studies. Patients in the RIBS IV (DES-ISR, n = 309) and RIBS V (BMS - ISR, n = 189) randomized trials, were used as controls. Most patients with BVS-ISR were treated with DES (76%). Patients with BVS-ISR were younger, had larger vessels, and after interventions had higher in-segment residual diameter stenosis (19 ± 13%, 15 ± 11%, 15 ± 12%, p <0.001) than those treated for DES-ISR and BMS-ISR, respectively. At 1-year clinical follow-up (obtained in 100% of patients) target lesion revascularization (6%) was similar to that seen in patients with DES-ISR and BMS-ISR (8.7% and 3.7%, p = 0.32). Freedom from death, myocardial infarction, and target vessel revascularization (primary clinical end point) was 8.5%, also similar to that found in patients with DES-ISR and BMS-ISR (14.2% and 7.4%, p = 0.09). Results were also similar when only patients treated with DES in each group were compared and remained unchanged after adjusting for potential confounders in baseline characteristics. Time to BVS-ISR did not influence angiographic or clinical results. This study demonstrates the safety and efficacy of coronary interventions for patients presenting with BVS-ISR. One-year clinical results in these patients are comparable to those seen in patients with ISR of metallic stents (ClinicalTrials.gov ID:NCT03167424).


Assuntos
Implantes Absorvíveis/efeitos adversos , Doença da Artéria Coronariana/cirurgia , Reestenose Coronária/cirurgia , Oclusão de Enxerto Vascular/cirurgia , Intervenção Coronária Percutânea/efeitos adversos , Stents/efeitos adversos , Idoso , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/mortalidade , Reestenose Coronária/diagnóstico , Reestenose Coronária/epidemiologia , Feminino , Oclusão de Enxerto Vascular/diagnóstico , Oclusão de Enxerto Vascular/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Intervenção Coronária Percutânea/instrumentação , Estudos Prospectivos , Reoperação , Fatores de Tempo , Resultado do Tratamento
9.
Psychiatry Res ; 186(2-3): 315-9, 2011 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-20858567

RESUMO

There is agreement in that strengthening the sets of neurobiological data would reinforce the diagnostic objectivity of many psychiatric entities. This article attempts to use this approach in borderline personality disorder (BPD). Assuming that most of the biological findings in BPD reflect common underlying pathophysiological processes we hypothesized that most of the data involved in the findings would be statistically interconnected and interdependent, indicating biological consistency for this diagnosis. Prospectively obtained data on scalp and sleep electroencephalography (EEG), clinical neurologic soft signs, the dexamethasone suppression and thyrotropin-releasing hormone stimulation tests of 20 consecutive BPD patients were used to generate a Bayesian network model, an artificial intelligence paradigm that visually illustrates eventual associations (or inter-dependencies) between otherwise seemingly unrelated variables. The Bayesian network model identified relationships among most of the variables. EEG and TSH were the variables that influence most of the others, especially sleep parameters. Neurological soft signs were linked with EEG, TSH, and sleep parameters. The results suggest the possibility of using objective neurobiological variables to strengthen the validity of future diagnostic criteria and nosological characterization of BPD.


Assuntos
Teorema de Bayes , Transtorno da Personalidade Borderline/diagnóstico , Transtorno da Personalidade Borderline/fisiopatologia , Adulto , Inteligência Artificial , Dexametasona , Eletroencefalografia , Eletrorretinografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Exame Neurológico , Transtornos do Sono-Vigília , Hormônio Liberador de Tireotropina/metabolismo , Adulto Jovem
10.
JACC Cardiovasc Imaging ; 14(9): 1742-1754, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33865783

RESUMO

OBJECTIVES: This study sought to clinically validate a novel 3-dimensional (3D) ultrafast cardiac magnetic resonance (CMR) protocol including cine (anatomy and function) and late gadolinium enhancement (LGE), each in a single breath-hold. BACKGROUND: CMR is the reference tool for cardiac imaging but is time-consuming. METHODS: A protocol comprising isotropic 3D cine (Enhanced sensitivity encoding [SENSE] by Static Outer volume Subtraction [ESSOS]) and isotropic 3D LGE sequences was compared with a standard cine+LGE protocol in a prospective study of 107 patients (age 58 ± 11 years; 24% female). Left ventricular (LV) mass, volumes, and LV and right ventricular (RV) ejection fraction (LVEF, RVEF) were assessed by 3D ESSOS and 2D cine CMR. LGE (% LV) was assessed using 3D and 2D sequences. RESULTS: Three-dimensional and LGE acquisitions lasted 24 and 22 s, respectively. Three-dimensional and LGE images were of good quality and allowed quantification in all cases. Mean LVEF by 3D and 2D CMR were 51 ± 12% and 52 ± 12%, respectively, with excellent intermethod agreement (intraclass correlation coefficient [ICC]: 0.96; 95% confidence interval [CI]: 0.94 to 0.97) and insignificant bias. Mean RVEF 3D and 2D CMR were 60.4 ± 5.4% and 59.7 ± 5.2%, respectively, with acceptable intermethod agreement (ICC: 0.73; 95% CI: 0.63 to 0.81) and insignificant bias. Both 2D and 3D LGE showed excellent agreement, and intraobserver and interobserver agreement were excellent for 3D LGE. CONCLUSIONS: ESSOS single breath-hold 3D CMR allows accurate assessment of heart anatomy and function. Combining ESSOS with 3D LGE allows complete cardiac examination in <1 min of acquisition time. This protocol expands the indication for CMR, reduces costs, and increases patient comfort.


Assuntos
Meios de Contraste , Imagem Cinética por Ressonância Magnética , Idoso , Feminino , Gadolínio , Humanos , Imageamento Tridimensional , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Reprodutibilidade dos Testes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA