Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
1.
Geriatr Nurs ; 60: 448-455, 2024 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-39423576

RESUMO

OBJECTIVES: This review investigates the current status of cognitive frailty risk prediction models for community-dwelling older adults, aiming to explore the shortcomings and provide insights for model optimisation. METHODS: We adhered to the PRISMA guidelines for scoping review and followed the Joanna Briggs Institute Manual for Evidence Synthesis. RESULTS: This article includes a total of 10 studies, revealing a prevalence of cognitive frailty ranging from 4.8 % to 39.6 %. The methods used for model construction included both logistic regression and machine learning. The predictors varied across the models, with age, education level, gender, and physical activity level being the most frequently cited factors. CONCLUSIONS: While most models showed good applicability, all models displayed a high risk of bias. Future endeavors should concentrate on leveraging existing tools to ensure standardization in development and conducting rigorous evaluations of prediction models for cognitive frailty in community-dwelling older adults.

2.
Res Gerontol Nurs ; 17(4): 202-212, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39047228

RESUMO

PURPOSE: To systematically review the available evidence regarding the prevalence and outcomes of cognitive frailty-a clinical syndrome characterized by the combination of physical frailty and cognitive impairment, without dementia-in community-dwelling older adults. METHOD: The following databases were searched: PubMed, Web of Science, Embase, EBSCO, Cochrane Central Register of Controlled Trials, ProQuest, CNKI, Wanfang, VIP, and CBMdisc (inception to October 2, 2023). RESULTS: Twenty-four studies were included (N = 62,169) reporting a median prevalence of cognitive frailty among community-dwelling older adults of 12.2%. Frailty with cognitive impairment was independently associated with increased all-cause mortality (adjusted 8-year hazard ratio [HR] = 2.6, 95% confidence interval [CI] [2.05, 3.30]). There was evidence of increased risk of 3-year mortality for frailty (adjusted HR = 1.92, 95% CI [1.26, 2.93]) and prefrailty (adjusted HR = 1.79, 95% CI [1.33, 2.41]) with cognitive impairment. There was also evidence of increased risk of dementia for frailty (adjusted 24-month HR = 6.19, 95% CI [2.74, 13.99]; adjusted 4-year HR = 4.98, 95% CI [2.17, 11.41]) and prefrailty (adjusted 4-year HR = 5.21, 95% CI [2.95, 9.20]; adjusted 5-year HR = 14.5, 95% CI [1.68, 125.1]) with cognitive impairment. Activities of daily living (ADL) dependence was more frequent in individuals with cognitive impairment and frailty (adjusted 4-year odds ratio = 5.6, 95% CI [2.13, 14.72]). CONCLUSION: Of community-dwelling older adults, 12.2% have cognitive frailty as well as increased risk of all-cause mortality, dementia, and ADL dependence. Further studies on prevention and treatment of cognitive frailty is warranted. Health care providers should formulate specific interventions to decrease the impact of cognitive frailty. [Research in Gerontological Nursing, 17(4), 202-212.].


Assuntos
Disfunção Cognitiva , Idoso Fragilizado , Fragilidade , Vida Independente , Humanos , Idoso , Prevalência , Disfunção Cognitiva/epidemiologia , Idoso Fragilizado/estatística & dados numéricos , Idoso Fragilizado/psicologia , Idoso de 80 Anos ou mais , Fragilidade/epidemiologia , Masculino , Feminino
3.
BMC Cardiovasc Disord ; 24(1): 93, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38326774

RESUMO

BACKGROUND: Cognitive frailty (CF) is currently a significant issue, and most of the associated factors discovered in current studies are not modifiable. Therefore, it is crucial to identify modifiable risk factors that can be targeted for interventions in patients with chronic heart failure (CHF). This study aimed to investigate the prevalence and modifiable risk factors of CF in CHF patients in China. METHODS: In this cross-sectional study, we sequentially enrolled patients diagnosed with CHF. CF served as the dependent variable, assessed through the Montreal Cognitive Assessment (MoCA) Scale and the FRAIL Scale. The independent variable questionnaire encompassed various components, including general demographic information, the Social Support Rating Scale (SSRS), the Simplified Nutrition Appetite Questionnaire (SNAQ), the Hamilton Depression Scale (HAMD), the Hamilton Anxiety Scale (HAMA), and the Minnesota Living with Heart Failure Questionnaire (MLHFQ). Logistic regression analysis was employed to identify independent factors contributing to CF. RESULTS: A total of 271 patients with CHF were included in the study. The overall prevalence of CF was found to be 49.4%, with 28.8% of patients exhibiting potentially reversible cognitive frailty and 20.7% showing reversible cognitive frailty. Among middle-young CHF patients, 10.7% had reversible cognitive frailty and 6.4% had potentially reversible cognitive frailty, with a prevalence of CF at 17.1%. Logistic regression analysis revealed that body mass index (OR = 0.826, 95%CI = 0.726-0.938), blood pressure level (OR = 2.323, 95%CI = 1.105-4.882), nutrition status (OR = 0.820, 95%CI = 0.671-0.979), and social support (OR = 0.745, 95%CI = 0.659-0.842) were independent factors associated with CF (p < 0.05). CONCLUSIONS: We observed a relatively high prevalence of CF among Chinese patients diagnosed with CHF. Many factors including BMI, blood pressure level, nutrition status, and social support emerging as modifiable risk factors associated with CF. We propose conducting clinical trials to assess the impact of modifying these risk factors. The outcomes of this study offer valuable insights for healthcare professionals, guiding them in implementing effective measures to improve the CF status in CHF patients during clinical practice.


Assuntos
Disfunção Cognitiva , Fragilidade , Insuficiência Cardíaca , Humanos , Idoso , Fragilidade/diagnóstico , Fragilidade/epidemiologia , Estudos Transversais , Prevalência , Fatores de Risco , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/complicações , China/epidemiologia , Cognição , Idoso Fragilizado , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/complicações
4.
Int J Nurs Knowl ; 35(2): 177-185, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37378541

RESUMO

PURPOSE: To perform a meta-analysis identifying the modifiable risk factors of cognitive frailty in the elderly. METHODS: We systematically searched databases including PubMed, EMBASE, China National Knowledge Infrastructure, China Science and Technology Journal Database, Wanfang Data Knowledge Service Platform from January 01, 2017 to March 26, 2022. Quantitative, original research reporting associated factors were included. FINDINGS: 7,854 records in total were identified, of which 14 articles (1 prospective, 13 cross-sectional) with 36 factors were included. Studies on cognitive frailty included 20,390 community-dwellers (≥60 years) from three countries. Meta-analysis indicated that depression [OR = 3.60, 95%CI (2.25,5.78), p < 0.01] and sleep problems [OR = 2.36, 95%CI (1.62,3.43), p < 0.01] were associated with cognitive frailty. CONCLUSIONS: Effective interventions targeting depression and sleep problems may lower the risk of cognitive frailty in the community seniors but need further study in high-quality, prospective studies. IMPLICATIONS FOR NURSING PRACTICE: Building on previous work, the objectives of this systematic review and meta-analysis were to explore potential modifiable risk factors for cognitive frailty in community-dwelling older adults, which is expected to throw light on the prevention of cognitive frailty.


Assuntos
Fragilidade , Transtornos do Sono-Vigília , Humanos , Idoso , Fragilidade/complicações , Vida Independente , Estudos Prospectivos , Idoso Fragilizado/psicologia , Estudos Transversais , Fatores de Risco , Transtornos do Sono-Vigília/complicações , Cognição
5.
PLoS One ; 18(7): e0288207, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37467248

RESUMO

PURPOSE: To inspect whether time management with radio frequency identification technology (RFID) reduces symptom onset-to-intravenous thrombolysis time (OTT) in acute ischemic stroke (AIS). METHODS: In the retrospective study, patients with AIS, transferred by Emergency Medical Services (EMS) to Hunan Provincial People's Hospital between September 2019 to June 2022, divided into three groups, as traditional group, in-hospital RFID group and whole process RFID group. Baseline characteristics and time metrics were compared. RESULTS: After the whole emergency process applied with RFID time management, Door to intravenous thrombolysis time (DNT) was reduced from 125.00±43.16 min to 32.59±25.45 min (F = 121.857, p<0.001), and OTT was reduced from 235.53±57.27 min to 144.31±47.96 min (F = 10.377, p<0.001). CONCLUSIONS: Time management with RFID is effective in reducing OTT in AIS patients with thrombolysis treatment.


Assuntos
Isquemia Encefálica , AVC Isquêmico , Dispositivo de Identificação por Radiofrequência , Acidente Vascular Cerebral , Humanos , Acidente Vascular Cerebral/tratamento farmacológico , Fibrinolíticos/uso terapêutico , AVC Isquêmico/tratamento farmacológico , Isquemia Encefálica/tratamento farmacológico , Terapia Trombolítica/métodos , Estudos Retrospectivos , Resultado do Tratamento
6.
Am J Emerg Med ; 69: 147-153, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37119700

RESUMO

BACKGROUND: Door-to-needle time (DNT) is a critical consideration in emergency management of acute ischemic stroke (AIS). Deficiencies in the widely applied standard hospital workflow process, based on international guidelines, impede rapid treatment of AIS patients. We developed an in-hospital stroke system to reduce DNT and optimize hospitals' emergency procedures. OBJECTIVES: To investigate the effect of the in-hospital stroke system on the hospital workflow for AIS patients. METHODS: We performed a retrospective study on AIS patients between June 2017 and December 2021. AIS cases were assigned to a pre-intervention group (before the in-hospital stroke system was established) and a post-intervention group (after the system's establishment). We compared the two groups' demographic features, clinical characteristics, treatments and outcomes, and time metrics data. RESULTS: We analyzed 1031 cases, comprising 474 and 557 cases in the pre-intervention and post-intervention groups, respectively. Baseline data were similar for both groups. Significantly more patients in the post-intervention group (41.11%) were treated with intravenous thrombolysis (IVT) or endovascular therapy (ET) compared with those in the pre-intervention group (8.65%) (p < 0.001). DNT was markedly improved (decreasing from 118 (80.5-137) min to 26 (21-38) min among patients in the post-intervention group treated with IVT or bridging ET. Consequently, a much higher proportion of these patients (92.64%) received IVT within 60 min compared with those in the pre-intervention group (17.39%) (p < 0.001). Consequently, their hospital stays were shorter (8 [6-11] days vs. 10 [8-12] days for the pre-intervention group; p < 0.001), and they showed improved National Institutes of Health Stroke Scale (NIHSS) scores at discharge (-2 [-5-0] vs. -1 [-2-0], p < 0.001). CONCLUSION: DNT was significantly reduced following implementation of the in-hospital stroke system, which contributed to improved patient outcomes measured by the length of hospital stay and NIHSS scores.


Assuntos
Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , AVC Isquêmico/tratamento farmacológico , Estudos Retrospectivos , Terapia Trombolítica/métodos , Acidente Vascular Cerebral/tratamento farmacológico , Hospitais , Fibrinolíticos/uso terapêutico , Tempo para o Tratamento , Resultado do Tratamento , Isquemia Encefálica/tratamento farmacológico
7.
Sensors (Basel) ; 24(1)2023 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-38202952

RESUMO

This article proposes a direction-of-arrival (DOA) estimation algorithm for a random sparse linear array based on a novel graph neural network (GNN). Unlike convolutional layers and fully connected layers, which do not interact well with information between different antennas, the GNN model can adapt to the goniometry problem of non-uniform random sparse linear arrays without any prior information by applying neighbor nodes' aggregation and update operations. This helps the model in learning signal features under complex environmental conditions. We train the model in an end-to-end way to reduce the complexity of the network. Experiments are conducted on the uniform and sparse linear arrays for various signal-to-noise ratio (SNR) and numbers of snapshots for comparison. We prove that the GNN model has superior angle estimation performance on arrays with large sparsity that cannot be used by traditional algorithms and surpasses existing deep learning models based on convolutional or fully connected structures. The proposed algorithm shows excellent DOA estimation performance under the complex conditions of limited snapshots, low signal-to-noise ratio, and large array sparsity as well. In addition, the algorithm has a low time calculation cost and is suitable for scenarios that require low latency.

8.
Polymers (Basel) ; 14(18)2022 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-36145854

RESUMO

Magnetorheological elastomer (MRE) is a kind of smart material, whose mechanical property can be controlled by the external magnetic field quickly and reversibly. The damping property of MRE is one of the most concerned properties when designing MRE based devices. In this work, the influence of gamma radiation on the damping property of MRE was investigated. Six different exposures of gamma radiation were applied to the MRE samples. The highest gamma radiation dose was up to 1 × 105 Gy(Si), which can cover most of the engineering application scenarios. The influence of gamma radiation on the damping-strain relation and the damping-magnetic-field relation were studied. The probable mechanisms were discussed in detail. It is found that the gamma radiation does not affect the variation trend of loss factor of MRE with increasing strain amplitude or magnetic flux density. But it affects the variation trend of the maximum change of strain-induced or magnetic-field-induced loss factor of MRE. Besides, with constant strain and constant magnetic flux density, the loss factor of MRE shows w-shape variation trend with increasing gamma radiation dose. It is considered to be resulted from the combined action of the intrinsic damping and the interfacial friction damping of MRE.

9.
Int J Med Mushrooms ; 24(5): 57-72, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35695589

RESUMO

In the study, we retrospectively reviewed cases of patients with acute mushroom poisoning admitted to seven hospitals from May 2016 to May 2021. In total, we analyzed 153 acute mushroom poisoning cases. Of these patients, 135 survived and 18 died; no correlation of Ganoderma lucidum treatment with in-hospital mortality was observed (odds ratio = 1.598, P = 0.589). We further analyzed 61 patients who survived with liver injury according to whether they were treated with G. lucidum. Both length of hospital stay and hospitalization expenses in the G. lucidum treatment group were significantly lower than the control, with values of 6.69 ± 3.98 days vs. 9.27 ± 5.30 days (t = 2.174, P = 0.034) and 16,336.49 ± 12,615.76 CNY vs. 27,540.08 ± 23,709.57 CNY (t = 2.382, P = 0.020), respectively. Moreover, cases with a blood purification treatment time > 48 h of the G. lucidum group were significantly less than that of the control (30% vs. 69.23%; χ2 = 4.891, P = 0.027). As a result, G. lucidum seems to be a beneficial treatment in acute mushroom poisoning with liver injury.


Assuntos
Agaricales , Intoxicação Alimentar por Cogumelos , Reishi , Humanos , Fígado , Intoxicação Alimentar por Cogumelos/terapia , Estudos Retrospectivos
10.
J Biochem Mol Toxicol ; 36(1): e22885, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34859534

RESUMO

Ginsenoside-Rg1 (G-Rg1), a saponin that is a primary component of ginseng, is effective against inflammatory diseases. The P2X purinoceptor 7 (P2X7) receptor is an ATP-gated ion channel that is predominantly expressed in immune cells and plays a key role in inflammatory processes. We investigated the role of G-Rg1 in sepsis-related cardiac dysfunction and the underlying mechanism involving the regulation of the P2X7 receptor. We detected cell viability, cytotoxicity, cellular reactive oxygen species (ROS) levels, and mitochondrial membrane potential (MMP) with or without G-Rg1 in lipopolysaccharide (LPS)- or hypoxia/reoxygenation (H/R)-induced H9c2 cell models of ischemia/reperfusion injury. We applied cecal ligation and puncture (CLP) to induce a mouse model of sepsis and measured the survival duration and cardiac function of CLP mice. Next, we quantified the ROS level, MMP, respiratory chain complex I-IV enzymatic activity, and mitochondrial fusion in CLP mouse heart tissues. We then investigated the role of G-Rg1 in repairing LPS-induced cell mitochondrial damage, including mitochondrial superoxidation products. The results showed that G-Rg1 inhibited LPS- or H/R-induced cardiomyocyte apoptosis, cytotoxicity, ROS levels, and mitochondrial damage. In addition, G-Rg1 prolonged the survival time of CLP mice. G-Rg1 attenuated LPS-induced superoxide production in the mitochondria of cardiomyocytes and the excessive release of cytochrome c from mitochondria into the cytoplasm. Most importantly, G-Rg1 suppressed LPS-mediated induction of proapoptotic Bax, activated Akt, induced GSK-3ß phosphorylation, and balanced mitochondrial calcium levels. Overall, G-Rg1 activates the Akt/GSK-3ß pathway through P2X7 receptors to inhibit sepsis-induced cardiac dysfunction and mitochondrial dysfunction.


Assuntos
Ginsenosídeos/farmacologia , Glicogênio Sintase Quinase 3 beta/metabolismo , Cardiopatias/metabolismo , Mitocôndrias Cardíacas/metabolismo , Miócitos Cardíacos/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Sepse/metabolismo , Transdução de Sinais , Animais , Linhagem Celular , Glicogênio Sintase Quinase 3 beta/genética , Cardiopatias/genética , Camundongos , Mitocôndrias Cardíacas/genética , Proteínas Proto-Oncogênicas c-akt/genética , Ratos , Receptores Purinérgicos P2X7/genética , Sepse/genética
11.
Sensors (Basel) ; 21(6)2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33802217

RESUMO

The progress brought by the deep learning technology over the last decade has inspired many research domains, such as radar signal processing, speech and audio recognition, etc., to apply it to their respective problems. Most of the prominent deep learning models exploit data representations acquired with either Lidar or camera sensors, leaving automotive radars rarely used. This is despite the vital potential of radars in adverse weather conditions, as well as their ability to simultaneously measure an object's range and radial velocity seamlessly. As radar signals have not been exploited very much so far, there is a lack of available benchmark data. However, recently, there has been a lot of interest in applying radar data as input to various deep learning algorithms, as more datasets are being provided. To this end, this paper presents a survey of various deep learning approaches processing radar signals to accomplish some significant tasks in an autonomous driving application, such as detection and classification. We have itemized the review based on different radar signal representations, as it is one of the critical aspects while using radar data with deep learning models. Furthermore, we give an extensive review of the recent deep learning-based multi-sensor fusion models exploiting radar signals and camera images for object detection tasks. We then provide a summary of the available datasets containing radar data. Finally, we discuss the gaps and important innovations in the reviewed papers and highlight some possible future research prospects.

12.
Geriatr Nurs ; 41(3): 261-273, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31706592

RESUMO

This review reports the most current evidence on the effects of exercise interventions on improving physical function, daily living activities and quality of life in community-dwelling frail older adults. CBMdisc, CNKI, Wanfang, VIP, MEDLINE, Cochrane Central Register of Controlled Trials (Central), Pubmed, Embase, Web of Science and EBSCO were searched from inception to July 2019. Exercise interventions were found to improve knee extension strength and normal speed and were beneficial in lower Time up and go test (TUG) and improving semi-tandem, Berg balance scale (BBS), Short Physical Performance Battery (SPPB), Physical Performance Test (PPT) and Activities of daily living (ADL). Further well-designed studies are needed to explore the most effective intervention type and dose.


Assuntos
Atividades Cotidianas , Terapia por Exercício , Idoso Fragilizado , Vida Independente , Qualidade de Vida/psicologia , Idoso , Humanos , Equilíbrio Postural , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos de Tempo e Movimento
13.
Med Sci Monit ; 23: 5793-5802, 2017 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-29211704

RESUMO

BACKGROUND Histone deacetylase (HDAC) inhibitors are emerging as a new class of anti-cancer drugs that promote cancer cell apoptosis, and include suberoylanilide hydroxamic acid (SAHA). The aim of this study was to investigate the mechanism of SAHA-induced apoptosis in human prostate cancer cell lines, DU145 and PC-3. MATERIAL AND METHODS Cell lines, DU145 and PC-3, were studied before and after treatment with SAHA. The effects of SAHA treatment on cell proliferation were studied using the MTT cell proliferation assay. Annexin-V-fluorescein isothiocyanate (FITC) and propidium iodide (PI) staining were used to study the effects of SAHA treatment on cell apoptosis. Western blotting, quantitative polymerase chain reaction (qPCR) and short interfering (si)RNA assays were performed to study the effects of SAHA treatment on apoptotic and cell cycle proteins and the Akt/FOXO3a signaling pathway. RESULTS Treatment with SAHA inhibited cell proliferation in human prostate cancer cell lines DU145 and PC-3 cells in a dose-dependent way. Cell cycle analysis and Annexin-V FITC/PI staining showed that treatment with SAHA resulted in G2/M cell cycle arrest and increased cell apoptosis in a dose-dependent way. Also, treatment with SAHA reduced the protein expression levels cyclin B and cyclin A2 and promoted the activation of FOXO3a by inhibiting Akt activation. Western blotting, the siRNA assay, and qPCR showed that FOXO3a, the Bcl-2 family of proteins, survivin, and FasL were involved in SAHA-induced apoptosis in prostate cancer cells grown in vitro. CONCLUSIONS Treatment with SAHA promoted apoptosis via the Akt/FOXO3a signaling pathway in prostate cancer cells in vitro.


Assuntos
Ácidos Hidroxâmicos/metabolismo , Anexina A5 , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Proteína Forkhead Box O3/efeitos dos fármacos , Proteína Forkhead Box O3/metabolismo , Inibidores de Histona Desacetilases/metabolismo , Histona Desacetilases , Humanos , Ácidos Hidroxâmicos/farmacologia , Proteínas Inibidoras de Apoptose , Masculino , Neoplasias da Próstata/tratamento farmacológico , Proteínas Proto-Oncogênicas c-akt/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Vorinostat , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Sci Rep ; 7(1): 16087, 2017 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-29167495

RESUMO

A survey was performed to assess the current management of targeted temperature management (TTM) in patients following cardiac arrest (CA) and whether healthcare providers will change target temperature after publication of 2015 American Heart Association guidelines for resuscitation in China. 52 hospitals were selected from whole of China between August to November 2016. All healthcare providers in EMs and/or ICUs of selected hospitals participated in the study. 1952 respondents fulfilled the survey (86.8%). TTM in CA patients was declared by 14.5% of physicians and 6.7% of the nurses. Only 4 of 64 departments, 7.8% of physicians and 5.7% of the nurses had implemented TH for CA patients. Since the publication of 2015 AHA guidelines, 33.6% of respondents declared no modification of target temperature, whereas 51.5% declared a target temperature's change in future practice. Respondents were more likely to choose 35∼36 °C-TTM (54.7%) after guidelines publication, as compared to that before guidelines publication they preferred 32∼34 °C-TTM (54.0%). TTM for CA patients was still in the early stage in China. Publication of 2015 resuscitation guidelines did have impact on choice of target temperature among healthcare providers. They preferred 35∼36 °C-TTM after guidelines publication.


Assuntos
Reanimação Cardiopulmonar , Parada Cardíaca/terapia , Hipotermia Induzida , Guias de Prática Clínica como Assunto , Publicações , Adulto , China , Coma/complicações , Geografia , Humanos , Padrões de Prática Médica
15.
Sensors (Basel) ; 16(6)2016 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-27271629

RESUMO

Traditional monopulse angle estimations are mainly based on phase comparison and amplitude comparison methods, which are commonly adopted in narrowband radars. In modern radar systems, wideband radars are becoming more and more important, while the angle estimation for wideband signals is little studied in previous works. As noise in wideband radars has larger bandwidth than narrowband radars, the challenge lies in the accumulation of energy from the high resolution range profile (HRRP) of monopulse. In wideband radars, linear frequency modulated (LFM) signals are frequently utilized. In this paper, we investigate the monopulse angle estimation problem for wideband LFM signals. To accumulate the energy of the received echo signals from different scatterers of a target, we propose utilizing a cross-correlation operation, which can achieve a good performance in low signal-to-noise ratio (SNR) conditions. In the proposed algorithm, the problem of angle estimation is converted to estimating the frequency of the cross-correlation function (CCF). Experimental results demonstrate the similar performance of the proposed algorithm compared with the traditional amplitude comparison method. It means that the proposed method for angle estimation can be adopted. When adopting the proposed method, future radars may only need wideband signals for both tracking and imaging, which can greatly increase the data rate and strengthen the capability of anti-jamming. More importantly, the estimated angle will not become ambiguous under an arbitrary angle, which can significantly extend the estimated angle range in wideband radars.

16.
J Int Med Res ; 44(3): 569-84, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27059291

RESUMO

OBJECTIVE: To evaluate the beneficial effects of hydroxysafflor yellow A (HSYA) on monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH) in rats, and to investigate the main pathophysiological mechanism of HSYA in preventing development of MCT-induced PAH. METHODS: Four groups (control, control with HSYA treatment, MCT-exposed, and MCT-exposed with HSYA treatment) were evaluated at day 28 following MCT exposure. Haemodynamic measurements, right ventricular hypertrophy, morphometry, inflammatory cytokines and oxidant expression were assessed. RESULTS: HSYA significantly reduced haemodynamic changes, right ventricular hypertrophy and morphometric changes induced by exposure to MCT. HYSA also suppressed MCT-induced inflammation and oxidative stress in rat pulmonary tissue. CONCLUSIONS: Experimental MCT-induced PAH may be reduced by HSYA treatment, and the mechanism may involve suppression of inflammation and oxidative stress.


Assuntos
Chalcona/análogos & derivados , Hipertensão Pulmonar/tratamento farmacológico , Quinonas/uso terapêutico , 8-Hidroxi-2'-Desoxiguanosina , Animais , Chalcona/farmacologia , Chalcona/uso terapêutico , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Hipertensão Pulmonar/complicações , Hipertensão Pulmonar/genética , Hipertensão Pulmonar/fisiopatologia , Hipertrofia Ventricular Direita/complicações , Hipertrofia Ventricular Direita/tratamento farmacológico , Hipertrofia Ventricular Direita/genética , Hipertrofia Ventricular Direita/fisiopatologia , Inflamação/patologia , Masculino , Malondialdeído/metabolismo , Monocrotalina , Estresse Oxidativo/efeitos dos fármacos , Quinonas/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Wistar , Superóxido Dismutase/metabolismo , Remodelação Vascular/efeitos dos fármacos
17.
J Phys Chem B ; 118(39): 11573-80, 2014 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-25201462

RESUMO

An anisotropic glucose oxidase-polymer surfactant nanoconjugate is synthesized and shown to exhibit complex temperature-dependent phase behavior in the solvent-free state. At close to room temperature, the nanoconjugate crystallizes as a mesolamellar soft solid with an expanded interlayer spacing of ca. 12 nm and interchain correlation lengths consistent with alkyl tail-tail and PEO-PEO ordering. The soft solid displays a birefringent spherulitic texture and melts at 40 °C to produce a solvent-free liquid protein without loss of enzyme secondary structure. The nanoconjugate melt exhibits a birefringent dendritic texture below the conformation transition temperature (Tc) of glucose oxidase (58 °C) and retains interchain PEO-PEO ordering. Our results indicate that the shape anisotropy of the protein-polymer surfactant globular building block plays a key role in directing mesolamellar formation in the solvent-free solid and suggests that the microstructure observed in the solvent-free liquid protein below Tc is associated with restrictions in the intramolecular motions of the protein core of the nanoconjugate.


Assuntos
Glucose Oxidase/química , Nanoconjugados/química , Polímeros/química , Tensoativos/química , Varredura Diferencial de Calorimetria , Glucose Oxidase/metabolismo , Polietilenoglicóis/química , Espalhamento a Baixo Ângulo , Eletricidade Estática , Temperatura de Transição , Difração de Raios X
18.
Chem Commun (Camb) ; 49(83): 9561-3, 2013 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-24018483

RESUMO

The surface of haemoglobin (Hb) is chemically modified to produce molecular dispersions of discrete core-shell Hb-polymer surfactant bionanoconjugates in water and organic solvents. The hybrid nanoconstructs exhibit peroxidase-like catalytic activity with enhanced turnover rates compared with native Hb in water.


Assuntos
Hemoglobinas/química , Nanoestruturas/química , Peroxidase/química , Polímeros/química , Tensoativos/química , Catálise , Hemoglobinas/metabolismo , Peróxido de Hidrogênio/metabolismo , Modelos Moleculares , Peroxidase/metabolismo , Solventes/química , Propriedades de Superfície , Água/química
19.
Physiol Meas ; 34(7): 799-812, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23780564

RESUMO

Our aim is to investigate the significance of electrogastrography in the treatment of esophageal variceal hemorrhage with octreotide. Electrogastrography was performed in patients with esophageal variceal hemorrhage before and during the treatment consisting of various doses of octreotide (25 ug h(-1) group and 50 ug h(-1) group). The dominant power of electrogastrography and its relationship with the hemostatic efficacy of octreotide treatment were evaluated. Dominant power of electrogastrography decreased significantly during treatment with octreotide (P < 0.05). The reduction in the amplitude of dominant power in the 50 ug h(-1) group was significantly larger than in the 25 ug h(-1) group (P < 0.05), and it was correlated with hemostatic efficacy of octreotide treatment. We conclude that octreotide treatment in patients with esophageal variceal hemorrhage can result in a significant decrease of dominant power, which correlates with the hemostatic efficacy of octreotide, so the change of dominant power could be used as a predictor of evaluating the treatment efficacy of octreotide in esophageal variceal hemorrhage patients.


Assuntos
Varizes Esofágicas e Gástricas/complicações , Varizes Esofágicas e Gástricas/tratamento farmacológico , Hemorragia/complicações , Hemorragia/tratamento farmacológico , Miografia/métodos , Octreotida/uso terapêutico , Adulto , Eletrodos , Feminino , Hemostasia/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Octreotida/farmacologia , Resultado do Tratamento
20.
Blood Purif ; 33(4): 300-6, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22652560

RESUMO

BACKGROUND/AIMS: Anticoagulation in hemodialysis (HD) patients at high risk of bleeding remains an intractable problem. Simulating endothelial cells by releasing anticoagulant on the membrane may be a promising alternative. METHODS: We modified a polyacrylonitrile (PAN) dialyzer by loading argatroban into its membrane and verified its anticoagulation efficiency and its influence on coagulation markers such as activated partial thromboplastin time (aPTT), D-dimer and thrombin-antithrombin complex (TAT) in an animal HD model. RESULTS: All HD sessions with the argatroban dialyzer were completed successfully with either no or minimal fiber clotting. D-dimer was lower in the argatroban group than in the PAN group; TAT and aPTT values were similar in the two groups, which suggests better anticoagulation and a similar influence on the coagulation system. CONCLUSION: HD with the argatroban dialyzer is feasible, safe and simple, and could be used in patients at high risk of bleeding.


Assuntos
Anticoagulantes/uso terapêutico , Coagulação Sanguínea/efeitos dos fármacos , Ácidos Pipecólicos/uso terapêutico , Diálise Renal/métodos , Resinas Acrílicas/química , Animais , Antitrombina III/metabolismo , Arginina/análogos & derivados , Cães , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Masculino , Membranas Artificiais , Tempo de Tromboplastina Parcial , Peptídeo Hidrolases/metabolismo , Sulfonamidas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA