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1.
Chem Rev ; 124(9): 5227-5420, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38661578

RESUMO

Ionic liquids (ILs) have unique physicochemical properties that make them advantageous for catalysis, such as low vapor pressure, non-flammability, high thermal and chemical stabilities, and the ability to enhance the activity and stability of (bio)catalysts. ILs can improve the efficiency, selectivity, and sustainability of bio(transformations) by acting as activators of enzymes, selectively dissolving substrates and products, and reducing toxicity. They can also be recycled and reused multiple times without losing their effectiveness. ILs based on imidazolium cation are preferred for structural organization aspects, with a semiorganized layer surrounding the catalyst. ILs act as a container, providing a confined space that allows modulation of electronic and geometric effects, miscibility of reactants and products, and residence time of species. ILs can stabilize ionic and radical species and control the catalytic activity of dynamic processes. Supported IL phase (SILP) derivatives and polymeric ILs (PILs) are good options for molecular engineering of greener catalytic processes. The major factors governing metal, photo-, electro-, and biocatalysts in ILs are discussed in detail based on the vast literature available over the past two and a half decades. Catalytic reactions, ranging from hydrogenation and cross-coupling to oxidations, promoted by homogeneous and heterogeneous catalysts in both single and multiphase conditions, are extensively reviewed and discussed considering the knowledge accumulated until now.

2.
An Acad Bras Cienc ; 94(suppl 1): e20210597, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35195188

RESUMO

Southern giant petrels (Macronectes giganteus) are found in the Antarctic. They build their nests with rock fragments, disturbing large areas during incubation and chick feeding periods; however, their impact on vegetation is unknown. Thus, we aimed to evaluate the effect of Petrel nests and associated breeding activities on the diversity and structure of cryptogam communities of Stinker Point, Elephant Island. We selected 13 nests in February and March 2012 and continue the monitoring in 2018. The area of direct influence of breeding activities was photographed to calculate plant community coverage. The results demonstrated that species richness, community coverage and composition, and beta diversity showed significant differences between active and inactive nests. The linear mixed-effect models revealed that the positive effect of nest area mainly caused variation in community coverage, but had a negative effect on beta diversity. Sphaerophorus globosus (lichen) grew around the inactive nests, sometimes forming a ring up to 1 m in diameter. This ring was then surrounded by the Chorisodontium acyphyllum moss colonized by S. globosus, and a final ring of Sanionia uncinata, colonized by the same lichen. Recently constructed nests are generally surrounded by Prasiola crispa and Sanionia uncinata carpets.


Assuntos
Aves , Melhoramento Vegetal , Animais , Regiões Antárticas
3.
An Acad Bras Cienc ; 94(suppl 1): e20191467, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35384969

RESUMO

Ice-free areas of Antarctica represent an important study region that helps us understand how human activity affects plant communities and soil properties. The goal of this study was to determine the changes in plant composition and soil properties around a whale bone skeleton (WB) near Ferraz Station, King George Island, Antarctica from 1972 to 2020 (48 years). The WB was assembled in 1972 by Jacques-Yves Cousteau and his team. It is located in a large moss field and visited by many tourists. We studied the plant composition and development based on historical and recent photographs and phytosociological studies from 1986 to 2020. The soil was sampled in February 2009 to determine general properties. The results showed that human activity surrounding the WB directly affected the plant community composition and soil properties. The Syntrichia cushions were positively affected by the calcium deposits from bone dissolution. The principal component analysis revealed that mineralization of the bones increased soil nutrient assembly. A strong phosphatization process was observed in the WB area, similar to that in ornithogenic soils. The WB on the marine terrace enhanced soil fertility and changed the plant community.


Assuntos
Poluentes do Solo , Solo , Animais , Regiões Antárticas , Esqueleto , Microbiologia do Solo , Poluentes do Solo/análise , Baleias
4.
Int J Clin Pract ; 75(8): e14347, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33977587

RESUMO

AIMS: To test the hypothesis of a semi-supervised home physical exercise programme that is likely to improve the functional mobility and quality of life (QOL) of elderly in the community. METHODS: This trial included elderly adults (88% female) aged 60 years or older and who were sedentary and without cognitive decline. The participants were randomly assigned to an intervention group (IG, home physical exercise and sleep hygiene) and a control group (CG, sleep hygiene). The International Questionnaire on Physical Activity, mental state mini-exam, World Health Organization Quality of Life Instrument-Older Adults Module (WHOQOL-OLD) and the Timed Up and Go (TUG) tests were conducted before and after the 12-week intervention period. RESULTS: The study was concluded with 125 elderly participants. Anthropometric data were indicative of pre-obesity, with a mean body mass index of 27.3 ± 4, a low-income socio-economic profile (78% ≤ 2 SM) and low schooling rates (76% ≤ 3 years of study). Most of the elderly (87%) were considered physically active with IPAQ > 150 min/week. The group of elderly people who performed the home physical exercise programme showed a significant improvement in functional mobility according to the time of execution of the TUG test before (9.1 ± 2) and after (7.1 ± 1) with an average reduction of 2 ± 1 s (P < .01). The difference in the QOL of the elderly who participated in the exercise protocol was also observed, verified through the WHOQOL-OLD global score, which presented an initial score of 85 ± 10, changing to 90.4 ± 9 after the intervention. CONCLUSION: Semi-supervised physical home exercise is safe and effective in improving the functional mobility and QOL of sedentary elderly people in the community.


Assuntos
Exercício Físico , Qualidade de Vida , Idoso , Terapia por Exercício , Feminino , Humanos , Masculino , Estudos Prospectivos , Inquéritos e Questionários
5.
Clin Exp Hypertens ; 43(3): 223-229, 2021 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-33198514

RESUMO

Background: Strength Training (ST) reduces the cardiovascular risk of hypertensive elderly people; however, there is a need for efficient and low-cost ST programs that aim to reduce blood pressure (BP) in elderly people with adherence and affectivity in this population. Objective: Evaluate the acute effect on BP and satisfaction with the practice of bodyweight-based strength training (BWST) in hypertensive older adults. Methods: Participants performed a BWST session and a control session (CS). The BWST consisted of six exercises, with three sets of 30 seconds. In the CS, no activity was performed. BP was measured before and at 0, 10, 20, and 30 minutes post-session. Participants' satisfaction was assessed. Results: Eleven older adults (65.8 ± 4.6 years; 7 men) participated in the study. There was an increase (p = .028) in systolic BP immediately after BWST, returning to baseline values in the intervals 10, 20, and 30 post-section. In the CS there was an increase (p = .009) 30 minutes post-session compared to 20 minutes. Between sessions, a lower systolic BP was found in BWST (-6.54 ± 3.31; p = .048) 30 minutes post-sessions. For satisfaction, 82% of participants were "totally satisfied" with BWST. Conclusion: The SBP is lower 30 minutes after BWST session than control session, and BWST promoted a pleasant affective response in hypertensive older adults.


Assuntos
Pressão Sanguínea/fisiologia , Peso Corporal/fisiologia , Hipertensão/fisiopatologia , Treinamento Resistido , Idoso , Estudos Cross-Over , Diástole/fisiologia , Exercício Físico/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Hemodinâmica/fisiologia , Humanos , Masculino , Satisfação do Paciente , Sístole/fisiologia
6.
BMC Med Inform Decis Mak ; 20(1): 45, 2020 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-32122371

RESUMO

BACKGROUND: Mammographic breast density is an important predictor of breast cancer, but its measurement has limitations related to subjectivity of visual evaluation or to difficult access for automatic volumetric measurement methods. Herein, we describe the design and clinical validation of Aguida, a software program for automated quantification of breast density from flat mammography images. MATERIALS AND METHODS: The software program was developed in MatLab. After image segmentation separating the background from the breast image, the operator positions a cursor defining a region of interest on the pectoralis major muscle from the mediolateral oblique view. Then, in the craniocaudal view, the threshold for separation of the dense tissue is based on the optical density of the pectoral muscle, and the proportion of dense tissue is calculated by the program. Mammograms obtained from 2 different occasions in 291 women were used for clinical evaluation. RESULTS: The intraclass correlation coefficient (ICC) between breast density measurements by the software and by a radiologist was 0.96, with a bias of only 0.67 percentage points and a 95% limit of agreement of 13.5 percentage points; the ICC was 0.94 in the interobserver reliability assessment by two radiologists with different experience; and the ICC was 0.98 in the intraobserver reliability assessment. The distribution among the density classes was close to the values obtained with the volumetric software. CONCLUSIONS: Measurement of breast density with the Aguida program from flat mammography images showed high agreement with the visual determination by radiologists, and high inter- and intra-observer reliability.


Assuntos
Densidade da Mama , Neoplasias da Mama/prevenção & controle , Mamografia , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Validação de Programas de Computador , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Feminino , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
7.
An Acad Bras Cienc ; 91(3): e20180559, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31531532

RESUMO

The average faculty productivity have been described as a rapid rise-short peak-gradual decline pattern. Way et al. (2017) have studied this pattern for faculty careers in Computer Science in North America using a piecewise linear model. In this paper, we use a similar methodology and study trajectories (N = 20655) of the Brazilian Computer Science community. First, we have evaluated how the median publication count of researchers is related to institution prestige and public vs. private administration. Second, we have studied how the annual publication rates have increased and its variation according to prestige ranks of institutions. Third, we have found the average trajectory can indeed be described as the canonical rapid increase and slower decrease in productivity. For individual trajectories of senior researchers we have observed only 4.5% of trajectories are well explained by the conventional narrative of rapid rise and gradual decline model. We also have found polynomial models of degrees 1 to 3 explain almost 63.1% of trajectories. The rest of trajectories are considered unstable and not well explained by neither of approaches.

8.
Neural Plast ; 2018: 9235796, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29849573

RESUMO

The Ts65Dn mouse is the most studied animal model of Down syndrome. Past research has shown a significant reduction in CA1 hippocampal long-term potentiation (LTP) induced by theta-burst stimulation (TBS), but not in LTP induced by high-frequency stimulation (HFS), in slices from Ts65Dn mice compared with euploid mouse-derived slices. Additionally, therapeutically relevant doses of the drug memantine were shown to rescue learning and memory deficits in Ts65Dn mice. Here, we observed that 1 µM memantine had no detectable effect on HFS-induced LTP in either Ts65Dn- or control-derived slices, but it rescued TBS-induced LTP in Ts65Dn-derived slices to control euploid levels. Then, we assessed LTP induced by four HFS (4xHFS) and found that this form of LTP was significantly depressed in Ts65Dn slices when compared with LTP in euploid control slices. Memantine, however, did not rescue this phenotype. Because 4xHFS-induced LTP had not yet been characterized in Ts65Dn mice, we also investigated the effects of picrotoxin, amyloid beta oligomers, and soluble recombinant human prion protein (rPrP) on this form of LTP. Whereas ≥10 µM picrotoxin increased LTP to control levels, it also caused seizure-like oscillations. Neither amyloid beta oligomers nor rPrP had any effect on 4xHFS-induced LTP in Ts65Dn-derived slices.


Assuntos
Região CA1 Hipocampal/efeitos dos fármacos , Região CA1 Hipocampal/fisiopatologia , Síndrome de Down/fisiopatologia , Antagonistas de Aminoácidos Excitatórios/administração & dosagem , Potenciação de Longa Duração , Memantina/administração & dosagem , Peptídeos beta-Amiloides/administração & dosagem , Animais , Modelos Animais de Doenças , Estimulação Elétrica , Feminino , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Picrotoxina/administração & dosagem , Proteínas Priônicas/administração & dosagem
9.
An Acad Bras Cienc ; 90(2 suppl 1): 2001-2010, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30066744

RESUMO

High resolution topography (HRT) surveys is an important tool to model landscapes, especially in zones subjected to strong environmental changes, such as Antarctica, where landform is highly influenced by cryoclasty and permafrost melting. The aim of this work was to obtain a high accurate DTM for Keller Peninsula, Maritime Antarctica. The survey study was assessed in the 2014/2015 and 2015/2016 during the austral summer, by using Terrestrial Laser Scanner (TLS). In order to cover 8 km² of the Peninsula, the TLS equipment was installed in 81 different points. Results of the DTM generated by TLS (hereafter, HRT-DTM), and the terrain variables Aspect, Slope and Hillshade obtained were compared with previous models generated by aerophotographic survey (hereafter, APG-DTM). RMSE for the HRT and APG-DTM were 0.726 and 2.397 m, respectively. Spatial resolution of the DTMs was 0.20 m. Morphometric variables obtained from the two methods presented visual differences on the thematic maps, especially related to the Aspect. Generalization was the main process, whereas interpolation occurred for the HRT survey, being the process of choice for the APG method. A large number of points are obtained by the TLS, providing a dense cloud of points, spatially well-distributed, enabling the generalization process to obtain surface models with high performance.


Assuntos
Mapeamento Geográfico , Regiões Antárticas , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional
10.
Noise Health ; 16(68): 57-62, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24583681

RESUMO

It is poor in the literature the behavior of the geometric indices of heart rate variability (HRV) during the musical auditory stimulation. The objective is to investigate the acute effects of classic musical auditory stimulation on the geometric indexes of HRV in women in response to the postural change maneuver (PCM). We evaluated 11 healthy women between 18 and 25 years old. We analyzed the following indices: Triangular index, Triangular interpolation of RR intervals and Poincarι plot (standard deviation of the instantaneous variability of the beat-to beat heart rate [SD1], standard deviation of long-term continuous RR interval variability and Ratio between the short - and long-term variations of RR intervals [SD1/SD2] ratio). HRV was recorded at seated rest for 10 min. The women quickly stood up from a seated position in up to 3 s and remained standing still for 15 min. HRV was recorded at the following periods: Rest, 0-5 min, 5-10 min and 10-15 min during standing. In the second protocol, the subject was exposed to auditory musical stimulation (Pachelbel-Canon in D) for 10 min at seated position before standing position. Shapiro-Wilk to verify normality of data and ANOVA for repeated measures followed by the Bonferroni test for parametric variables and Friedman's followed by the Dunn's posttest for non-parametric distributions. In the first protocol, all indices were reduced at 10-15 min after the volunteers stood up. In the protocol musical auditory stimulation, the SD1 index was reduced at 5-10 min after the volunteers stood up compared with the music period. The SD1/SD2 ratio was decreased at control and music period compared with 5-10 min after the volunteers stood up. Musical auditory stimulation attenuates the cardiac autonomic responses to the PCM.


Assuntos
Estimulação Acústica , Frequência Cardíaca/fisiologia , Música , Postura/fisiologia , Adolescente , Adulto , Análise de Variância , Eletrocardiografia , Feminino , Humanos , Adulto Jovem
11.
Turk Kardiyol Dern Ars ; 42(2): 139-46, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24643145

RESUMO

OBJECTIVES: The effects of chronic music auditory stimulation on the cardiovascular system have been investigated in the literature. However, data regarding the acute effects of different styles of music on cardiac autonomic regulation are lacking. The literature has indicated that auditory stimulation with white noise above 50 dB induces cardiac responses. We aimed to evaluate the acute effects of classical baroque and heavy metal music of different intensities on cardiac autonomic regulation. STUDY DESIGN: The study was performed in 16 healthy men aged 18-25 years. All procedures were performed in the same soundproof room. We analyzed heart rate variability (HRV) in time (standard deviation of normal-to-normal R-R intervals [SDNN], root-mean square of differences [RMSSD] and percentage of adjacent NN intervals with a difference of duration greater than 50 ms [pNN50]) and frequency (low frequency [LF], high frequency [HF] and LF/HF ratio) domains. HRV was recorded at rest for 10 minutes. Subsequently, the volunteers were exposed to one of the two musical styles (classical baroque or heavy metal music) for five minutes through an earphone, followed by a five-minute period of rest, and then they were exposed to the other style for another five minutes. The subjects were exposed to three equivalent sound levels (60-70dB, 70-80dB and 80-90dB). The sequence of songs was randomized for each individual. RESULTS: Auditory stimulation with heavy metal music did not influence HRV indices in the time and frequency domains in the three equivalent sound level ranges. The same was observed with classical baroque musical auditory stimulation with the three equivalent sound level ranges. CONCLUSION: Musical auditory stimulation of different intensities did not influence cardiac autonomic regulation in men.


Assuntos
Estimulação Acústica , Sistema Nervoso Autônomo/fisiologia , Frequência Cardíaca/fisiologia , Música , Adolescente , Adulto , Frequência Cardíaca/efeitos da radiação , Humanos , Adulto Jovem
12.
Noise Health ; 15(65): 281-7, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23771427

RESUMO

The literature investigated the effects of chronic baroque music auditory stimulation on the cardiovascular system. However, it lacks in the literature the acute effects of different styles of music on cardiac autonomic regulation. To evaluate the acute effects of baroque and heavy metal music on heart rate variability (HRV) in women. The study was performed in 21 healthy women between 18 and 30 years old. We excluded persons with previous experience with music instrument and those who had affinity with the song styles. All procedures were performed in the same sound-proof room. We analyzed HRV in the time (standard deviation of normal-to-normal respiratory rate (RR) intervals, root-mean square of differences between adjacent normal RR intervals in a time interval, and the percentage of adjacent RR intervals with a difference of duration greater than 50 ms) and frequency (low frequency [LF], high frequency [HF], and LF/HF ratio) domains. HRV was recorded at rest for 10 min. Subsequently they were exposed to baroque or heavy metal music for 5 min through an earphone. After the first music exposure they remained at rest for more 5 min and them they were exposed again to baroque or heavy metal music. The sequence of songs was randomized for each individual. The power analysis provided a minimal number of 18 subjects. Shapiro-Wilk to verify normality of data and analysis of variance for repeated measures followed by the Bonferroni test for parametric variables and Friedman's followed by the Dunn's post-test for non-parametric distributions. During the analysis of the time-domain indices were not changed. In the frequency-domain analysis, the LF in absolute units was reduced during the heavy metal music stimulation compared to control. Acute exposure to heavy metal music affected the sympathetic activity in healthy women.


Assuntos
Estimulação Acústica/classificação , Sistema Nervoso Autônomo/fisiologia , Frequência Cardíaca/fisiologia , Música , Adolescente , Adulto , Análise de Variância , Feminino , Humanos , Fatores de Tempo , Adulto Jovem
13.
Nutrients ; 15(15)2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37571250

RESUMO

Obesity is a troubling public health problem as it increases risks of sleep disorders, respiratory complications, systemic arterial hypertension, cardiovascular diseases, type 2 diabetes mellitus, and metabolic syndrome (MetS). As a measure to counteract comorbidities associated with severe obesity, bariatric surgery stands out. This study aimed to investigate the adiponectin/leptin ratio in women with severe obesity with and without MetS who had undergone Roux-en-Y gastric bypass (RYGB) and to characterize the biochemical, glucose, and inflammatory parameters of blood in women with severe obesity before and after RYGB. Were enrolled females with severe obesity undergoing RYGP with MetS (n = 11) and without (n = 39). Anthropometric data and circulating levels of glucose, total cholesterol, high-density lipoprotein (HDL), non-HDL total cholesterol, low-density lipoprotein (LDL), adiponectin, and leptin were assessed before and 6 months after RYGB. Significant reductions in weight, body mass index, and glucose, total cholesterol, LDL, and leptin were observed after surgery, with higher levels of HDL, adiponectin, and adiponectin/leptin ratio being observed after surgery compared to the preoperative values of those. This study demonstrated that weight loss induced by RYGB in patients with severe obesity with or without MetS improved biochemical and systemic inflammatory parameters, particularly the adiponectin/leptin ratio.


Assuntos
Diabetes Mellitus Tipo 2 , Derivação Gástrica , Síndrome Metabólica , Obesidade Mórbida , Humanos , Feminino , Leptina , Síndrome Metabólica/complicações , Obesidade Mórbida/complicações , Obesidade Mórbida/cirurgia , Adiponectina , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/cirurgia , Diabetes Mellitus Tipo 2/metabolismo , Obesidade/complicações , Colesterol , Glucose
14.
Proc Natl Acad Sci U S A ; 106(33): 14138-43, 2009 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-19666557

RESUMO

Severe dengue infection in humans causes a disease characterized by thrombocytopenia, increased levels of cytokines, increased vascular permeability, hemorrhage, and shock. Treatment is supportive. Activation of platelet-activating factor (PAF) receptor (PAFR) on endothelial cells and leukocytes induces increase in vascular permeability, hypotension, and production of cytokines. We hypothesized that activation of PAFR could account for the major systemic manifestations of dengue infection. Inoculation of adult mice with an adapted strain of Dengue virus caused a systemic disease, with several features of the infection in humans. In PAFR(-/-) mice, there was decreased thrombocytopenia, hemoconcentration, decreased systemic levels of cytokines, and delay of lethality, when compared with WT infected mice. Treatment with UK-74,505, an orally active PAFR antagonist, prevented the above-mentioned manifestations, as well as hypotension and increased vascular permeability, and decreased lethality, even when started 5 days after virus inoculation. Similar results were obtained with a distinct PAFR antagonist, PCA-4246. Despite decreased disease manifestation, viral loads were similar (PAFR(-/-)) or lower (PAFR antagonist) than in WT mice. Thus, activation of PAFR plays a major role in the pathogenesis of experimental dengue infection, and its blockade prevents more severe disease manifestation after infection with no increase in systemic viral titers, suggesting that there is no interference in the ability of the murine host to deal with the infection. PAFR antagonists are disease-modifying agents in experimental dengue infection.


Assuntos
Vírus da Dengue/metabolismo , Dengue/metabolismo , Dengue/virologia , Glicoproteínas da Membrana de Plaquetas/fisiologia , Receptores Acoplados a Proteínas G/fisiologia , Aedes , Animais , Encéfalo/metabolismo , Encéfalo/virologia , Linhagem Celular , Citocinas/metabolismo , Di-Hidropiridinas/farmacologia , Modelos Animais de Doenças , Humanos , Imidazóis/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Glicoproteínas da Membrana de Plaquetas/antagonistas & inibidores , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Carga Viral
15.
Biointerphases ; 17(3): 031005, 2022 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-35688674

RESUMO

The polysaccharide ß-glucan, found in the cell wall of cereals such as wheat, oats, and barley, is believed to lower the concentration of bad cholesterol in humans, but the molecular-level mechanisms responsible for such an action are unknown. In this study, we use Langmuir monolayers of cholesterol and dipalmitoyl phosphatidyl choline (DPPC) as cell membrane models that are made to interact with ß-glucan. Neat cholesterol and mixed cholesterol/DPPC monolayers were expanded upon incorporating ß-glucan from the aqueous subphase. This incorporation was found to induce ordering in mixed monolayers and dehydration of the carbonyl group at higher cholesterol concentrations. These effects are attributed to hydrophobic interactions as identified with polarization-modulated infrared reflection-absorption spectroscopy. They correlate well with the hypothesis that cholesterol levels can be lowered by the formation of soluble fibers with ß-glucan through hydrophobic interactions, blocking cholesterol absorption by the organism.


Assuntos
beta-Glucanas , 1,2-Dipalmitoilfosfatidilcolina/química , Membrana Celular , Colesterol/química , Humanos , Interações Hidrofóbicas e Hidrofílicas , Análise Espectral
16.
IEEE Trans Neural Netw Learn Syst ; 33(6): 2350-2364, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34596562

RESUMO

In this article, we argue that the unsatisfactory out-of-distribution (OOD) detection performance of neural networks is mainly due to the SoftMax loss anisotropy and propensity to produce low entropy probability distributions in disagreement with the principle of maximum entropy. On the one hand, current OOD detection approaches usually do not directly fix the SoftMax loss drawbacks, but rather build techniques to circumvent it. Unfortunately, those methods usually produce undesired side effects (e.g., classification accuracy drop, additional hyperparameters, slower inferences, and collecting extra data). On the other hand, we propose replacing SoftMax loss with a novel loss function that does not suffer from the mentioned weaknesses. The proposed IsoMax loss is isotropic (exclusively distance-based) and provides high entropy posterior probability distributions. Replacing the SoftMax loss by IsoMax loss requires no model or training changes. Additionally, the models trained with IsoMax loss produce as fast and energy-efficient inferences as those trained using SoftMax loss. Moreover, no classification accuracy drop is observed. The proposed method does not rely on outlier/background data, hyperparameter tuning, temperature calibration, feature extraction, metric learning, adversarial training, ensemble procedures, or generative models. Our experiments showed that IsoMax loss works as a seamless SoftMax loss drop-in replacement that significantly improves neural networks' OOD detection performance. Hence, it may be used as a baseline OOD detection approach to be combined with current or future OOD detection techniques to achieve even higher results.


Assuntos
Redes Neurais de Computação , Extremidade Superior , Entropia
17.
Respir Care ; 2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36347565

RESUMO

BACKGROUND: Mobility is human body movement in all its forms, including bed-to-chair transfer, walking, daily tasks, participating in work and social functions, exercising, and using public transport. The mobility of people living with COPD is affected negatively by the disease symptoms. However, limited data are available on the life-space mobility in people with COPD on long-term oxygen therapy (LTOT). This study aimed to explore the life-space mobility in subjects with COPD on LTOT and verify whether life-space mobility is associated with comorbidities and symptoms, activity in daily life, exercise capacity performance, and quality of life. METHODS: This cross-sectional study enrolled 61 subjects with COPD on LTOT (73.0 ± 8.8 y, FEV1 41.7 ± 16.0% predicted, on LTOT for 2.8 ± 3.3 y). Life-space mobility (Life-Space Assessment), LTOT usage time, comorbidities (Charlson comorbidity index), need for support from a caregiver, exercise capacity (6-min step test), dyspnea (modified Medical Research Council scale), activities of daily living (ADLs, Katz scale), and health-related quality of life (EuroQol 5-Dimension Questionnaire) were assessed. RESULTS: Mobility restriction was identified in 90% of participants. Life-space mobility was negatively associated with the number of comorbidities (rs = -0.31, P = .02), dyspnea symptom (rs = -0.60, P < .001), and positively associated with basic ADLs performance (rs = 0.59, P < .001) and exercise capacity (rs = 0.49, P < .001). Dyspnea and exercise capacity were independent predictors of vital space mobility. CONCLUSIONS: Subjects with COPD on LTOT had limited life-space mobility. Interventions to reduce dyspnea and improve exercise capacity should be prioritized to increase this population's domestic and community mobility.

18.
Infect Immun ; 79(4): 1741-9, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21263020

RESUMO

The plasma level of the chemokine CCL3 is elevated in patients with chronic severe schistosomiasis mansoni. We have previously shown that CCL3(-/-) mice with experimental infection showed diminished pathology and worm burden compared to those of wild-type (WT) mice. To elucidate further the role of CC chemokines during schistosomiasis mansoni infection, we evaluated the course of infection in C57BL/6J mice deficient in CCR5, one of the receptors for CCL3. The CCR5 deficiency proved to be remarkably deleterious to the host, since mortality rates reached 70% at 14 weeks postinfection in CCR5(-/-) mice and 19% in WT mice. The increased lethality was not associated with an increased parasite burden, since similar numbers of eggs and adult worms were found in mice from both groups. Liver granulomas of chronically infected CCR5(-/-) mice were larger and showed greater numbers of cells and collagen deposition than liver granulomas from WT mice. This was associated with higher levels of production of intereleukin-5 (IL-5), IL-13, CCL3, and CCL5 in infected CCR5(-/-) mice than in infected WT mice. Moreover, at 8 weeks after infection, just before changes in pathology and mortality, the numbers of FoxP3-positive cells were lower in liver granulomas of CCR5(-/-) mice than in WT mice. In conclusion, the CCR5 deletion is deleterious to mice infected with Schistosoma mansoni, and this is associated with enhanced fibrosis and granulomatous inflammation.


Assuntos
Granuloma/patologia , Inflamação/patologia , Receptores CCR5/deficiência , Animais , Modelos Animais de Doenças , Feminino , Granuloma/imunologia , Imuno-Histoquímica , Inflamação/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Receptores CCR5/imunologia , Schistosoma mansoni/imunologia , Esquistossomose/imunologia , Esquistossomose/patologia
19.
J Org Chem ; 76(24): 10140-7, 2011 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-22029265

RESUMO

An acetate anion bearing an imidazolium cation as its charge tag was reacted with M(OAc)(2) complexes (where M = Ni, Cu, and Pd; in situ reaction) to form members of a new class of charge-tagged metal complexes. The formation of these unprecedented precatalysts with potential for cross-coupling reactions was confirmed by electrospray ionization (and tandem) mass spectrometry. The catalytic performance of the palladium complex was tested in Heck and Suzuki cross-coupling reactions, often with superior activity and yields as compared with Pd(OAc)(2).

20.
Physiol Rep ; 8(12): e14486, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32562388

RESUMO

INTRODUCTION: The Ts65Dn mouse is the most widely used animal model of Down syndrome (DS). Differences in autonomic regulation of heart rate variability (HRV) in individuals with DS have been hypothesized. Pharmacological studies in animal models may help us understand mechanisms underlying observed changes in HRV in people with DS. OBJECTIVE: To investigate the use a new, noninvasive technique to assess cardiac autonomic modulation in Ts65Dn mice under the effect of adrenergic and cholinergic agonists. METHOD: We recorded electrocardiograms (ECGs) from 12 Ts65Dn and 12 euploid control mice. A 30-min baseline recording was followed by the injection of an adrenergic (isoproterenol [Iso]) or cholinergic (carbachol [CCh]) agonist. Heart rate and HRV were analyzed using a series of methods customized for mice. RESULTS AND DISCUSSION: The ECG apparatus described here allowed us to detect noninvasively long series of heartbeats in freely-moving animals. During baseline conditions, the yield of detectable heartbeats was 3%-27% of the estimated total number of events, which increased to 35%-70% during the 15-min period after either Iso or CCh injections. Ts65Dn mice displayed a robust enhanced Iso-induced negative chronotropic rebound response compared with euploid control mice. We observed a significantly smaller CCh response in Ts65Dn versus control euploid mice in the 6- to 10-min-interval postcarbachol injection. CONCLUSION: This work showed that the techniques described here are sufficient for this type of study. However, future studies involving the use of more selective pharmacological agents and/or genetic manipulations will be key to advance a mechanistic understanding of cardiac autonomic regulation in DS.


Assuntos
Sistema Nervoso Autônomo/fisiologia , Carbacol/intoxicação , Síndrome de Down/fisiopatologia , Frequência Cardíaca/fisiologia , Isoproterenol/farmacologia , Agonistas Adrenérgicos beta/farmacologia , Animais , Sistema Nervoso Autônomo/efeitos dos fármacos , Carbacol/farmacologia , Agonistas Colinérgicos/farmacologia , Modelos Animais de Doenças , Eletrocardiografia/métodos , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Medição de Risco
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