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BACKGROUND: Despite recent interest in community-based screening programs to detect undiagnosed cognitive disorder, little is known about whether screening leads to further diagnostic evaluation, or the effects of such programs in terms of actual changes in patient or caregiver behavior. This study followed up informants of older adults (i.e. caregivers of patients who completed informant-based screening regarding the patient) following participation in a study screening for undiagnosed memory problems, to explore uptake of further diagnostic evaluation or treatment, advance planning or preparations, lifestyle changes, medication adherence, and use of support services. METHODS: A total of 140 informants of older adult patients were surveyed four to fifteen months following participation in a cognitive screening study. The informants were interviewed with a study-specific survey about cognitive assessment, advance planning, lifestyle changes, and use of support services and general medication adherence. RESULTS: A minority of patients and informants had engaged in advance planning or made relevant lifestyle changes following cognitive screening. Those assessed as being at higher risk of memory problems were more likely to have attended a full diagnostic evaluation, engaged in support services and experienced medication adherence difficulties. CONCLUSION: Only a small proportion of patients participating in cognitive screening subsequently engaged in diagnostic evaluation, advance planning, or lifestyle changes. However, those with higher risk of cognitive impairment were generally more likely to take some action following cognitive screening. Those at higher risk were also more vulnerable due to greater difficulties with medication adherence.
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Planejamento Antecipado de Cuidados , Disfunção Cognitiva/diagnóstico , Adesão à Medicação/psicologia , Transtornos da Memória/diagnóstico , Idoso , Cuidadores , Cognição/fisiologia , Disfunção Cognitiva/psicologia , Feminino , Humanos , Estilo de Vida , Masculino , Transtornos da Memória/psicologia , Atenção Primária à Saúde , SingapuraRESUMO
BACKGROUND AND PURPOSE: The study of silent stroke has been limited to imaging of chronic infarcts; acute incidental infarcts (AII) detected on brain magnetic resonance imaging have been less investigated. This study aims to describe prevalence and risk factors of AII in a community and a clinic-based population. METHODS: Subjects were drawn from 2 ongoing studies: Epidemiology of Dementia in Singapore study, which is a subsample from a population-based study, and a clinic-based case-control study. Subjects from both studies underwent similar clinical and neuropsychological assessments and brain magnetic resonance imaging. Prevalence of AII from these studies was determined. Subsequently, risk factors of AII were examined using multivariable logistic regression models. RESULTS: AII were seen in 7 of 623 (1.2%) subjects in Epidemiology of Dementia in Singapore (mean age, 70.9±6.8 years; 45% men) and in 12 of 389 (3.2%) subjects (mean age, 72.1±8.3 years; 46% men) in the clinic-based study. AII were present in 0.8% of subjects with no cognitive impairment, 1.9% of those with cognitive impairment not dementia, and 4.2% of subjects with dementia. Significant association of AII was found with cerebral microbleeds (≥5) in the Epidemiology of Dementia in Singapore (odds ratio, 6.76; 95% confidence interval, 1.28-35.65; P=0.02) and in the clinic-based cohort (odds ratio, 4.65; 95% confidence interval, 1.39-15.53; P=0.01). There was no association of AII with hypertension, diabetes mellitus, or hyperlipidemia. CONCLUSIONS: AII are more likely to be present in those with cognitive impairment. Although a cause-effect relationship between the presence of AII and cognitive impairment is plausible, the association may be because of under-reporting of symptoms by individuals with cognitive impairment. The association between AII and cerebral microbleeds may indicate cerebral vasculopathy, independent of traditional vascular risk factors.
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Infarto Encefálico/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Infarto Encefálico/complicações , Estudos de Casos e Controles , Transtornos Cognitivos/complicações , Feminino , Humanos , Achados Incidentais , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Prevalência , Fatores de RiscoRESUMO
Extracranial carotid artery disease has been shown to be related to cognitive deficits. However, limited data are available on intracranial stenosis (ICS) and cognitive impairment. We investigate the association between ICS and cognitive impairment in Chinese. Subjects (n=278), recruited from the Epidemiology of Dementia in Singapore Study, underwent comprehensive clinical evaluation, neuropsychological testing, and brain magnetic resonance imaging (MRI), including 3-dimensional-time-of-flight magnetic resonance angiography (MRA). Cognitive function was expressed as composite and domain-specific Z-scores. Cognitive impairment no dementia and dementia were diagnosed according to internationally accepted diagnostic criteria. Linear and logistic regression models were adjusted for age, sex, education, vascular risk factors, and other MRI markers. A total of 29 (10.4%) persons had ICS on MRA, which was significantly associated with both composite cognitive Z-scores [mean difference in Z-score, presence vs. absence of ICS: -0.37 (95% confidence interval: -0.63, -0.12)] and specific domains including executive function, language, visuomotor speed, verbal memory, and visual memory. ICS was also related to significant cognitive impairment (odds ratio: 5.10 [1.24 to 21.02]). With respect to other MRI markers, adjusted for the presence of lacunar infarcts, the associations of ICS with both composite and domain-specific Z-scores, and significant cognitive impairment became nonsignificant; however, adjustment for other MRI markers did not alter these associations. In this Chinese population, presence of ICS was associated with cognitive impairment independent of vascular risk factors. These associations may be mediated through the presence of infarcts.
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Povo Asiático/etnologia , Doenças Arteriais Cerebrais/diagnóstico , Doenças Arteriais Cerebrais/etnologia , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/etnologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças Arteriais Cerebrais/psicologia , Transtornos Cognitivos/psicologia , Constrição Patológica/diagnóstico , Constrição Patológica/etnologia , Constrição Patológica/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes NeuropsicológicosRESUMO
BACKGROUND: Previous studies have assessed the association between ankle-brachial index (ABI) and cognition, mainly using brief cognitive tests. We investigated whether ABI was associated with cognition independent of neuroimaging markers of cerebrovascular disease. METHODS: Chinese subjects (n = 278, aged ≥60 years) were recruited from the ongoing Epidemiology of Dementia in Singapore (EDIS) Study. Ankle and brachial blood pressures were measured, and low ABI was defined as ≤0.9. A neuropsychological battery was utilized to determine cognition. Cognitive impairment no dementia (CIND) and dementia were diagnosed according to standard diagnostic criteria. Magnetic resonance imaging (MRI) was used to obtain semiquantitative and quantitative markers of cerebrovascular disease and atrophy. RESULTS: A low ABI was related to the presence of intracranial stenosis (odds ratio, OR = 1.71; 95% confidence interval, CI: 1.13-2.59), but not with the presence of infarcts, microbleeds or grey matter, white matter and white matter lesion volumes. Furthermore, a low ABI was associated with poorer overall cognitive function and CIND-moderate/dementia (OR = 2.26; 95% CI: 1.11-4.59), independent of cardiovascular risk factors, and the MRI markers related to cerebrovascular disease and atrophy. CONCLUSION: We found an association between a low ABI and cognitive impairment, independent of any MRI marker of cerebral small vessel disease or large artery atherosclerotic disease.
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Índice Tornozelo-Braço , Transtornos Cerebrovasculares/diagnóstico , Transtornos Cognitivos/diagnóstico , Idoso , China , Constrição Patológica , Humanos , Imageamento por Ressonância Magnética , Masculino , Testes NeuropsicológicosRESUMO
The form of soil nitrogen input significantly affects soil CO2 emission. As a new form of nitrogen input, biochar-loaded ammonia nitrogen not only reduces the input of chemical nitrogen fertilizer in farmland but also reduces the cost of environmental treatment. It is of great significance to promote the zero growth of national chemical fertilizer, the prevention and control of farmland non-point source pollution, and the realization of the national goal of "carbon peak" and "carbon neutralization." Through an indoor culture experiment, the effects of different nitrogen input forms on soil carbon emission, enzyme activity, and microbial community were studied through four treatments:no fertilization (CK), single application of chemical nitrogen fertilizer (CF), biochar combined application of chemical nitrogen fertilizer (BF), and biochar-loaded ammonia nitrogen (BN). The results showed that compared with that in CF, BF significantly increased cumulative carbon emissions (66.24 %), whereas BN had no significant difference. It is worth noting that the cumulative carbon emissions were significantly reduced by 35.28 % compared with that in BF and BN. Compared with those in CF and BF, the activities of ß-glucosidase, peroxidase, and polyphenol oxidase treated with BN significantly increased by 20.25 % and 5.20 %, respectively. Compared with that in CF, the BF treatment increased microbial community richness and community diversity, whereas the BN treatment decreased microbial community richness. Compared with that in BF, the relative abundance of Proteobacteria decreased by 11.16 %, and the relative abundance of Actinobacteria and Bacteroidota increased by 8.12 % and 5.83 %, respectively, in which xylosidase activity was the most important soil factor affecting microbial community structure. The relative abundance of Chloroflexi was significantly correlated with cellobiose hydrolase activity, and the relative abundance of Gemmatimonadetes was significantly correlated with ß-glucosidase activity. There was a very significant correlation between the relative abundance of Proteobacteria and cumulative carbon emissions. To summarize, compared with those under biochar combined with chemical nitrogen fertilizer, biochar loaded with ammonia nitrogen significantly reduced cumulative carbon emissions, and its emission reduction effect was better. The results of this study will be beneficial to the landing of the national "double carbon strategy," the healthy development of the biological natural gas industry, the construction of the national green cultivation circular agriculture system, and the realization of the national zero growth strategy of chemical fertilizer.
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Amônia , Carbono , Carvão Vegetal , Fertilizantes , Nitrogênio , Microbiologia do Solo , Solo , Carvão Vegetal/química , Solo/química , Microbiota/efeitos dos fármacos , Bactérias/classificação , Bactérias/crescimento & desenvolvimento , Bactérias/efeitos dos fármacos , Dióxido de Carbono/análiseRESUMO
OBJECTIVE: To study the prevalence of and associated factors for cognitive impairment and dementia in community dwelling Chinese from Singapore. METHODS: This study includes Chinese subjects from the Epidemiology of Dementia in Singapore (EDIS) study, aged ≥60 years, who underwent comprehensive examinations, including cognitive screening with the locally validated Abbreviated Mental Test and Progressive Forgetfulness Questionnaire. Screen positive participants subsequently underwent extensive neuropsychological testing and cerebral MRI. Cognitive impairment no dementia (CIND) and dementia were diagnosed according to internationally accepted criteria. The prevalence of cognitive impairment and dementia were computed per 5 year age categories and gender. To examine the relationship between baseline associated factors and cognitive impairment, we used logistic regression models to compute odd ratios with 95% CI. RESULTS: 1538 Chinese subjects, aged ≥60 years, underwent cognitive screening: 171 (15.2%) were diagnosed with any cognitive impairment, of whom 84 were CIND mild, 80 CIND moderate and seven had dementia. The overall age adjusted prevalence of CIND mild was 7.2%; CIND moderate/dementia was 7.9%. The prevalence increased with age, from 5.9% in those aged 60-64 years to 31.3% in those aged 75-79 years and 44.1% in those aged ≥80 years. Multivariate analysis revealed age, diabetes and hyperlipidaemia to be independently associated with cognitive impairment. CONCLUSIONS: In present study, the overall prevalence of cognitive impairment and dementia in Chinese was 15.2%, which is in the same range as the prevalence reported in Caucasian and other Asian populations.
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Disfunção Cognitiva/epidemiologia , Demência/epidemiologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Encéfalo/patologia , China/etnologia , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/epidemiologia , Transtornos Cognitivos/patologia , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/patologia , Demência/diagnóstico , Demência/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neuroimagem , Testes Neuropsicológicos , Prevalência , Fatores Sexuais , Singapura/epidemiologiaRESUMO
CONTEXT: The prevalence of age-related cognitive decline has been on the rise as the global population age, putting the independence and quality of life of elderly at risk. Anthocyanin, as a subclass of dietary flavonoids, may have a beneficial impact on cognitive outcomes. OBJECTIVES: To examine the effects of dietary anthocyanin supplementation on cognition of the cognitively healthy middle-aged and older adults. DATA SOURCES: PubMed, ScienceDirect, CINAHL, EMBASE, ProQuest and Cochrane databases were searched. DATA EXTRACTION AND ANALYSIS: Thirteen studies were included in this meta-analysis. Anthocyanin-rich supplementation was found to significantly improve the processing speed of the older adults (95%CI 0.08, 0.44; P = 0.004). No significant differences were observed between intervention and control groups on memory, attention, executive function and psychomotor performance. Current neuroimaging studies have found promising effects of anthocyanin supplementation on brain activation and cerebral perfusion. CONCLUSION: Anthocyanin-rich supplementation may preserve cognitive processing speed and neuro-activities in older adults, which improves their daily functioning and quality of life. This review provides useful insights to guide direction and methodological designs for future studies to explore the underlying mechanisms of anthocyanins. SYSTEMATIC REVIEW AND META-ANALYSIS REGISTRATION: PROSPERO registration No. CRD42021228007.
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Antocianinas , Qualidade de Vida , Idoso , Pessoa de Meia-Idade , Humanos , Antocianinas/farmacologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Cognição , Suplementos NutricionaisRESUMO
BACKGROUND: Peer feedback (PF) has attracted much attention in health profession education with growing evidence on its benefits. However, it lacks a proper framework to guide its operation, which raises concerns about its quality in nursing education. PURPOSE: To compare the effects of a 3-phase PF versus faculty feedback (FF) on students' reflective abilities and clinical competencies after simulated practice, and its impacts on peer tutors' feedback practices and empowerment level. METHODS: This study used a 3-arm pretest-posttest quasi-experimental methodology. RESULTS: Peer verbal feedback significantly increased students' reflective abilities and clinical competencies, while peer video feedback significantly increased clinical competencies. However, FF outcomes did not reach significance. Peer tutors' empowerment level did not significantly improve, but feedback practices were perceived as comparable with FF. CONCLUSIONS: Peer feedback can potentially improve students' reflective abilities and clinical competencies. Proper feedback training with a structured framework will likely enhance peer tutors' feedback practices.
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Estudantes de Enfermagem , Humanos , Competência Clínica , Pesquisa em Educação em EnfermagemRESUMO
Agrobacterium tumefaciens-mediated transformation (ATMT) is becoming a popular effective system as an insertional mutagenesis tool in filamentous fungi. An efficient Agrobacterium tumefaciens-mediated transformation approach was developed for the plant pathogenic fungus, F. oxysporum, the causal agent of Apple replant disease (ARD) in China. Four parameters were selected to optimize efficiencies of transformation. A. tumefaciens concentration, conidial concentration of F. oxysporum, and co-culture temperature and time have a significant influence on all parameters. Transformants emit green fluorescence under fluorescence microscopy. The integration of a mitotically stable hygromycin resistance gene (hph) in the genome is confirmed by PCR. The transformation efficiency can reach up to 300 transformants per 106 conidia under optimal conditions. This ATMT method is an efficient tool for insertional mutagenesis of F. oxysporum.
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Agrobacterium tumefaciens , Fusarium , Agrobacterium tumefaciens/genética , DNA Bacteriano , Mutagênese Insercional , Esporos Fúngicos/genética , Transformação GenéticaRESUMO
OBJECTIVE: To explore the synergic mechanism of ginsenoside Rg1 (Rg1) and aconitine (AC) by acting on normal neonatal rat cardiomyocytes (NRCMs) and pentobarbital sodium (PS)-induced damaged NRCMs. METHODS: The toxic, non-toxic, and effective doses of AC and the most suitable compatibility concentration of Rg1 for both normal and damaged NRCMs exposed for 1 h were filtered out by 3- (4,5)-dimethylthiahiazo (-z-y1)-3,5-diphenytetrazoliumromide, respectively. Then, normal NRCMs or impaired NRCMs were treated with chosen concentrations of AC alone or in combination with Rg1 for 1 h, and the cellular activity, cellular ultrastructure, apoptosis, leakage of acid phosphatase (ACP) and lactate dehydrogenase (LDH), intracellular sodium ions [Na+], potassium ions [K+] and calcium ions [Ca2+] levels, and Nav1.5, Kv4.2, and RyR2 genes expressions in each group were examined. RESULTS: For normal NRCMs, 3000 µ mol/L AC significantly inhibited cell viability (P<0.01), promoted cell apoptosis, and damaged cell structures (P<0.05), while other doses of AC lower than 3000 µ mol/L and the combinations of AC and Rg1 had little toxicity on NRCMs. Compared with AC acting on NRCMs alone, the co-treatment of 3000 and 10 µ mol/L AC with 1 µ mol/L Rg1 significantly decreased the level of intracellular Ca2+ (P<0.01 or P<0.05), and the co-treatment of 3000 µ mol/L AC with 1 µ mol/L Rg1 significantly decreased the level of intracellular Ca2+ via regulating Nav1.5, RyR2 expression (P<0.01). For damaged NRCMs, 1500 µ mol/L AC aggravated cell damage (P<0.01), and 0.1 and 0.001 µ mol/L AC showed moderate protective effect. Compared with AC used alone, the co-treatment of Rg1 with AC reduced the cell damage, 0.1 µ mol/L AC with 1 µ mol/L Rg1 significantly inhibited the level of intracellular Na+ (P<0.05), 1500 µ mol/L AC with 1 µ mol/L Rg1 significantly inhibited the level of intracellular K+ (P<0.01) via regulating Nav1.5, Kv4.2, RyR2 expressions in impaired NRCMs. CONCLUSION: Rg1 inhibited the cardiotoxicity and enhanced the cardiotonic effect of AC via regulating the ion channels pathway of [Na+], [K+], and [Ca2+].
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Ginsenosídeos , Aconitina/farmacologia , Animais , Apoptose , Cardiotônicos/farmacologia , Cardiotoxicidade/tratamento farmacológico , Sobrevivência Celular , Ginsenosídeos/farmacologia , RatosRESUMO
Given the limitations of existing therapeutic agents for treatment of postmenopausal osteoporosis, there still remains a need for more options with both efficacy and less adverse effects. Cistanche deserticola Y. C. Ma is known as a popular tonic herb traditionally used to treatment deficiency of kidney energy including muscle weakness in minority area of Asian counties. Based on the theory of "kidney dominate bone," an ovariectomized (OVX) rat model of postmenopausal osteoporosis was used to evaluate the therapeutic effect of C. deserticola extract (CDE) on bone loss. Forty eight female Sprague-Dawley rats, aged about 12 weeks, were randomly assigned into six groups including sham group orally administrated with 0.5% carboxymethyl cellulose sodium (CMC-Na) (sham), positive group treated with 1 mg/kg of estradiol valerate (EV), low, moderate, and high dosage groups orally administrated with 200, 400, and 800 mg/kg/day of CDE, respectively. After 3 months of continuous intervention, CDE exhibited significant anti-osteoporotic activity evidenced by the enhanced total bone mineral density, ameliorated bone microarchitecture; increased alkaline phosphatase activity; decreased deoxypyridinoline, cathepsin K, tartrate-resistant acid phosphatase, and malondialdehyde levels; whereas the body, uterus, and vagina weights in OVX rats were not influenced by CDE intervention. In addition, a seemed contradictory phenomenon on levels of calcium and phosphorus between OVX and sham rats were observed and elucidated. Mechanistically, CDE significantly down-regulated the levels of TRAF6, RANKL, RANK, NF-κB, IKKß, NFAT2, and up-regulated the phosphatidylinositol 3-kinase (PI3K), AKT, osteoprotegerin, and c-Fos expressions, which implied CDE could suppress RANKL/RANK-induced activation of downstream NF-κB and PI3K/AKT pathways, and ultimately, preventing activity of the key osteoclastogenic proteins NFAT2 and c-Fos. All of the data suggested CDE possessed potential anti-osteoporotic activity and this effect was, at least in part, involved in modulation of RANKL/RANK/TRAF6-mediated NF-κB and PI3K/AKT signaling as well as c-Fos and NFAT2 levels. Therefore, CDE may represent a useful promising remedy candidate for treatment of postmenopausal osteoporosis.
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Targeted screening for dementia among older adults in primary healthcare has potential benefits such as better clinical outcomes and the opportunity to access services. Cognitive screening can be followed up by further diagnostic assessment to determine a diagnosis of dementia. Unfortunately, the rates of accepting further diagnostic assessment following cognitive screening are low. The objective of this study was to explore the caregivers' decision-making process regarding uptake of diagnostic assessment following positive screening results. A qualitative design was employed, and interpretative phenomenological analysis was used to analyze the data. Three major themes in caregiver decision-making were identified: gathering information, protecting the patient, and balancing obligation and convenience in caregiving. These findings suggest that the decision-making process involved effort to process information through observations of the patient and that caregivers emphasized quality of life.
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OBJECTIVE: Alzheimer's disease and vascular dementia are responsible for more than 80% of dementia cases. These two conditions share common risk factors including hypertension. Cerebral small vessel disease (CSVD) is strongly associated with both hypertension and cognitive impairment. In this review, we identify the pathophysiological changes in CSVD that are caused by hypertension and further explore the relationship between CSVD and cognitive impairment. DATA SOURCES: We searched and scanned the PubMed database for recently published literatures up to December 2017. We used the keywords of "hypertension", "cerebral small vessel disease", "white matter lesions", "enlarged perivascular spaces", "lacunar infarcts", "cerebral microbleeds", and "cognitive impairment" in the database of PubMed. STUDY SELECTION: Articles were obtained and reviewed to analyze the hypertension-induced pathophysiological changes that occur in CSVD and the correlation between CSVD and cognitive impairment. RESULTS: In recent years, studies have demonstrated that hypertension-related changes (e.g., small vascular lesions, inflammatory reactions, hypoperfusion, oxidative stress, damage to autoregulatory processes and the blood-brain barrier, and cerebral amyloid angiopathy) can occur over time in cerebral small vessels, potentially leading to lower cognitive function when blood pressure (BP) control is poor or lacking. Both isolated and co-occurrent CSVD can lead to cognitive deterioration, and this effect may be attributable to a dysfunction in either the cholinergic system or the functionality of cortical and subcortical tracts. CONCLUSIONS: We explore the currently available evidence about the hypertensive vasculopathy and inflammatory changes that occur in CSVD. Both are vital prognostic indicators of the development of cognitive impairment. Future studies should be performed to validate the relationship between BP levels and CSVD progression and between the numbers, volumes, and anatomical locations of CSVD and cognitive impairment.
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Doenças de Pequenos Vasos Cerebrais/complicações , Doenças de Pequenos Vasos Cerebrais/etiologia , Disfunção Cognitiva/etiologia , Hipertensão/complicações , Pressão Sanguínea/fisiologia , Doenças de Pequenos Vasos Cerebrais/fisiopatologia , Disfunção Cognitiva/fisiopatologia , Humanos , Hipertensão/fisiopatologiaRESUMO
Three series of novel macrolactams and macrolactones--12-alkoxyimino-tetradecanlactam, 12-alkoxyiminopentadecanlactam, and 12-alkoxyiminodecanlactone derivatives (7A, 7B, and 7C)--were synthesized from corresponding 12-oxomacrolactams and 12-oxomacrolactone. Their structures were confirmed by 1H NMR and elemental analysis. The Z and E isomers of 7A and 7B were separated, and their configurations were determined by 1H NMR. These compounds showed fair to excellent fungicidal activities against Rhizoctonia solani Kühn. It is interesting that the Z and E isomers of most of the compounds have quite different fungicidal activities. The fact that the compounds have a gradual increase of fungicidal activity in the order of 7A, 7C, and 7B indicated that the macrocyclic derivatives with a hydrogen-bonding acceptor (=N-O-) and a hydrogen-bonding donor (-CONH-) on the ring, and a three methylenes distance (CH2CH2CH2) between these two functional groups, exhibited the best fungicidal activity. The bioassay also showed that 7B not only has good fungicidal activity but also may have a broad spectrum of fungicidal activities.
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Fungicidas Industriais/farmacologia , Lactamas Macrocíclicas/síntese química , Lactamas Macrocíclicas/farmacologia , Lactonas/síntese química , Lactonas/farmacologia , Oximas/química , Ligação de Hidrogênio , Compostos Macrocíclicos/síntese química , Compostos Macrocíclicos/farmacologia , Espectroscopia de Ressonância Magnética , Rhizoctonia/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
Using split plot and then-split plot design, effects of water-nitrogen coupling on photosynthesis and ultrastructure of cucumber (Cucumis sativus) (Jinyou No.35) under CO2 enrichment were investigated. The main plot had two CO2 concentrations: ambient CO2 concentration (400 µmol·mol-1, A) and doubled CO2 concentration (800±20 µmol·mol-1, E). The split plot had two treatments: no drought stress (95% of field capacity, W) and drought stress (75% of field capacity, D). The then-split plot contained low nitrogen treatment (450 kg·hm-2, N1) and high nitrogen treatment (900 kg·hm-2, N2). The results showed that under the condition of drought and high nitrogen, increasing CO2 enhanced the cucumber plant height, and no matter what kinds of water treatment, CO2 enrichment increased the leaf area significantly under high nitrogen. Under the condition of normal irrigation, the photosynthetic rate, stomatal conductance and transpiration rate of high nitrogen treatment were higher than low nitrogen treatment, while it was under the drought condition. Elevated CO2 enhanced the water use efficiency of cucumber leaf which increased with increasing nitrogen application rate. Under drought stress, cucumber adaxial surface porosity density was increased, and the CO2 enrichment and high nitrogen significantly reduced the stomatal density. Increasing nitrogen application improved the number of chloroplast, and reduced that of starch grains. Drought stress decreased the number of chloroplast, but tended to promote the number of starch grains. Drought stress increased the chloroplast length and width, and the size of the starch grains, while high nitrogen reduced the length and width of the chloroplast and starch grains. CO2 enrichment and high nitrogen increased grana thickness and layers (except ADN2), and the slice layer of EDN2 was significantly higher than that of ADN2. In conclusion, CO2 enrichment and suitable water and nitrogen could promote the development of chloroplast thylakoid membrane system, significantly increase the thickness of grana and the number of grana lamella, and effectively improve the chloroplast structure of cucumber, which would benefit the photosynthesis of cucumber plants and ability to utilize CO2 and water and nitrogen.
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Cucumis sativus , Nitrogênio , Fotossíntese , Dióxido de Carbono , Folhas de Planta , ÁguaRESUMO
INTRODUCTION: The Stroke and Cognition consortium (STROKOG) aims to facilitate a better understanding of the determinants of vascular contributions to cognitive disorders and help improve the diagnosis and treatment of vascular cognitive disorders (VCD). METHODS: Longitudinal studies with ≥75 participants who had suffered or were at risk of stroke or TIA and which evaluated cognitive function were invited to join STROKOG. The consortium will facilitate projects investigating rates and patterns of cognitive decline, risk factors for VCD, and biomarkers of vascular dementia. RESULTS: Currently, STROKOG includes 25 (21 published) studies, with 12,092 participants from five continents. The duration of follow-up ranges from 3 months to 21 years. DISCUSSION: Although data harmonization will be a key challenge, STROKOG is in a unique position to reuse and combine international cohort data and fully explore patient level characteristics and outcomes. STROKOG could potentially transform our understanding of VCD and have a worldwide impact on promoting better vascular cognitive outcomes.
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The effects of doubled CO2 concentration on non-structural carbohydrate metabolism of cucumber (Cucumis sativus L. cv. 'Jinyou No.1') seedlings under drought stress were investigated. Split plot design was deployed, with two levels of CO2 concentrations (ambient CO2 concentration, 380 µmol . mol-1, and doubled CO2 concentration, 760±20 µmol . mol-1) in the main plots, and three levels of water treatments (control, moderate drought stress, and severe drought stress) simulated by PEG 6000 in the split-plots. The results showed that non-structural carbohydrates of cucumber leaves, including glucose, fructose, sucrose, and stachyose, increased with the doubling of CO2 concentration, which resulted in the decreased osmotic potential, improving the drought stress in cucumber seedlings. During the drought stress, sucrose synthase, soluble acid invertase and al- kaline invertase started with an increase, and followed with a decline in the leaves. In the root system, however, soluble acid invertase and alkaline invertase increased gradually throughout the whole process, whereas sucrose phosphate synthase firstly increased and then decreased. The treatment of doubled CO2 enhanced the activity of sucrose synthase, but decreased the activity of sucrose phosphate synthase. The synergistic action of the two enzymes and invertase accelerated the decomposition of sucrose and inhibited the synthesis of sucrose, leading to the accumulation of hexose, which lowered the cellular osmotic potential and enhanced the water uptake capacity. In conclusion, doubled CO2 concentration could alleviate the adverse effects of drought stress and improve the drought tolerance of cucumber seedlings. Such mitigating effect on cucumber was more significant under severe drought stress.
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Metabolismo dos Carboidratos , Dióxido de Carbono/química , Cucumis sativus/metabolismo , Secas , Plântula/metabolismo , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Estresse Fisiológico , Sacarose/metabolismo , Água , beta-Frutofuranosidase/metabolismoRESUMO
OBJECTIVE: To investigate the relationship between cognitive impairment and somatosensory evoked magnetic field and auditory evoked magnetic field changes in elderly male patients with subcortical ischemic vascular dementia (SIVD). METHODS: Magnetoencephalography (MEG) was used to record evoked magnetic field changes from 4 SIVD patients (76-88 years), 3 patients with vascular cognitive impairment with no dementia (VCI-ND; 74-87 years), and 6 healthy volunteers (72-85 years). Latency peaks, equivalent current dipole (ECD) strength, and bilateral ECD position were recorded. The MEG data were superimposed on magnetic resonance imaging to produce magnetic source imaging. RESULTS: Compared to controls, SIVD patients showed increased M20 latency and ECD strength. There were no significant differences in M20 inter-hemispheric positions across diagnostic categories. At M100, SIVD patients showed delayed auditory evoked magnetic field latency compared to controls. However, ECD strength and 3-dimensional inter-hemispheric differences were similar across the groups at the M100 measurement. CONCLUSIONS: Changes in somatosensory and auditory evoked magnetic field changes correlated with cognitive impairment in SIVD patients. Magnetic field latency measures may provide an objective and sensitive index for early dementia detection and monitoring of cognitive function.
Assuntos
Isquemia Encefálica/complicações , Transtornos Cognitivos/fisiopatologia , Transtornos Cognitivos/psicologia , Demência Vascular/fisiopatologia , Demência Vascular/psicologia , Campos Magnéticos , Estimulação Acústica , Idoso , Idoso de 80 Anos ou mais , Córtex Auditivo/fisiopatologia , Estudos de Casos e Controles , Cérebro/fisiopatologia , Demência Vascular/etiologia , Estimulação Elétrica , Humanos , Magnetoencefalografia , Masculino , Córtex Somatossensorial/fisiopatologiaRESUMO
Based on the data of bottom trawl surveys in the vicinity of Pearl River estuary in August (summer), October (autumn), December (winter) 2006, and April (spring) 2007, the faunal characteristics and distribution pattern of crustaceans were analyzed. A total of 54 species belonging to 25 genera, 17 families, and 2 orders were collected, including 22 species of shrimps, 22 species of crabs, and 10 species of squills. Most of the crustaceans were tropical-subtropical warm-water species, a few of them were eurythermal species, and no warm-water and cold-water species occurred. Euryhaline species were most abundant, followed by halophile species, and the low-salinity species were the least. Most of the crustacean species belonged to the fauna of Indian Ocean-western Pacific Ocean. The faunal assemblages were closer to those of the East China Sea, Philippine Sea, Indonesia Sea, and the Japan Sea, and estranger with those of the Yellow Sea, Bohai Sea, and Korea Sea. The dominant species were Metapenaeus joyner, Oratosquilla oratoria, Charybdis miles, Portunus sanguinolentus, Harpiosquilla harpax, Charybdis feriatus, Charybdis japonica, Oratosquilla nepa, Solenocera crassicornis, Portunus trituberculatus, and Calappa philargius. The crustaceans had the largest species number (33) in autumn and the least one (26) in spring, and the highest stock density at the water depth of < 40 m, especially at 10-20 m. The average stock density of the crustaceans was estimated to be 99.60 kg x km(-2), with the highest (198.93 kg x km(-2)) in summer and the lowest (42.35 kg x km(-2)) in spring. Of the 3 species groups, crabs had the highest stock density (41.81 kg x km(-2)), followed by shrimps (38.91 kg x km(-2)), and squills (18.88 kg x km(-2)). The stock densities of the 3 species groups showed an obvious seasonal variation. Shrimps had the highest stock density (120.32 kg x km(-2)) in summer and the lowest density (0.67 kg x km(-2)) in spring, while crabs and squills had the highest density (62.01 and 29.49 kg x km(-2), respectively) in winter and the lowest density (24.64 and 6.30 kg x km(-2), respectively) in autumn.