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1.
BMC Neurol ; 24(1): 329, 2024 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-39244562

RESUMO

BACKGROUND: Early neurological deterioration (END) occurs in many patients with acute ischemic stroke due to a variety of causes. Although pharmacologically induced hypertension (PIH) and anticoagulants have been investigated in several clinical trials for the treatment of END, the efficacy and safety of these treatments remain unclear. Here, we investigated whether PIH or anticoagulation is better as a rescue therapy for the progression of END in patients with lacunar stroke. METHODS: This study included patients with lacunar stroke who received rescue therapy with END within 3 days of symptom onset between April 2014 and August 2021. In the PIH group, phenylephrine was administered intravenously for 24 h and slowly tapered when symptoms improved or after 5 days of PIH. In the anticoagulation group, argatroban was administered continuously intravenously for 2 days and twice daily for next 5 days. We compared END recovery, defined as improvement in NIHSS from baseline, excellent outcomes (0 or 1 mRS at 3 months), and safety profile. RESULTS: Among the 4818 patients with the lacunar stroke, END occurred in 147 patients. Seventy-nine patients with END received PIH (46.9%) and 68 patients (46.3%) received anticoagulation therapy. There was no significant difference in age (P = 0.82) and sex (P = 0.87) between the two groups. Compared to the anticoagulation group, the PIH group had a higher incidence of END recovery (77.2% vs. 51.5%, P < 0.01) and excellent outcomes (34.2% vs. 16.2%, P = 0.04). PIH was associated with END (HR 2.49; 95% CI 1.06-5.81, P = 0.04). PIH remained associated with END recovery (adjusted HR 3.91; 95% CI 1.19-12.90, P = 0.02). Safety outcomes, like hemorrhagic conversion and mortality, were not significantly different between the two groups. CONCLUSIONS: As a rescue therapy for the progression of END in lacunar stroke patients, PIH with phenylephrine was more effective with similar safety compared to anticoagulation with argatroban.


Assuntos
Anticoagulantes , Acidente Vascular Cerebral Lacunar , Humanos , Masculino , Feminino , Acidente Vascular Cerebral Lacunar/tratamento farmacológico , Idoso , Pessoa de Meia-Idade , Anticoagulantes/uso terapêutico , Anticoagulantes/administração & dosagem , Hipertensão/tratamento farmacológico , Hipertensão/complicações , Idoso de 80 Anos ou mais , Sulfonamidas/uso terapêutico , Sulfonamidas/administração & dosagem , Arginina/análogos & derivados , Arginina/uso terapêutico , Arginina/administração & dosagem , Resultado do Tratamento , Anti-Hipertensivos/uso terapêutico , Anti-Hipertensivos/administração & dosagem , Estudos Retrospectivos , Progressão da Doença , Ácidos Pipecólicos
2.
Int J Mol Sci ; 25(2)2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38256144

RESUMO

As the global population ages, the prevalence of Parkinson's disease (PD) is steadily on the rise. PD demonstrates chronic and progressive characteristics, and many cases can transition into dementia. This increases societal and economic burdens, emphasizing the need to find effective treatments. Among the widely recognized causes of PD is the abnormal accumulation of proteins, and autophagy dysfunction accelerates this accumulation. The resultant Lewy bodies are also commonly found in Alzheimer's disease patients, suggesting an increased potential for the onset of dementia. Additionally, the production of free radicals due to mitochondrial dysfunction contributes to neuronal damage and degeneration. The activation of astrocytes and the M1 phenotype of microglia promote damage to dopamine neurons. The drugs currently used for PD only delay the clinical progression and exacerbation of the disease without targeting its root cause, and come with various side effects. Thus, there is a demand for treatments with fewer side effects, with much potential offered by natural products. In this study, we reviewed a total of 14 articles related to herbal medicines and natural products and investigated their relevance to possible PD treatment. The results showed that the reviewed herbal medicines and natural products are effective against lysosomal disorder, mitochondrial dysfunction, and inflammation, key mechanisms underlying PD. Therefore, natural products and herbal medicines can reduce neurotoxicity and might improve both motor and non-motor symptoms associated with PD. Furthermore, these products, with their multi-target effects, enhance bioavailability, inhibit antibiotic resistance, and might additionally eliminate side effects, making them good alternative therapies for PD treatment.


Assuntos
Doença de Alzheimer , Produtos Biológicos , Doenças Mitocondriais , Doença de Parkinson , Plantas Medicinais , Humanos , Doença de Parkinson/tratamento farmacológico , Produtos Biológicos/farmacologia , Produtos Biológicos/uso terapêutico , Extratos Vegetais
3.
Stroke ; 54(9): 2296-2303, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37551589

RESUMO

BACKGROUND: Poststroke cognitive impairment (PSCI) occurs in about half of stroke survivors. Cumulative evidence indicates that functional outcomes of stroke are worse in women than men. Yet it is unknown whether the occurrence and characteristics of PSCI differ between men and women. METHODS: Individual patient data from 9 cohorts of patients with ischemic stroke were harmonized and pooled through the Meta-VCI-Map consortium (n=2343, 38% women). We included patients with visible symptomatic infarcts on computed tomography/magnetic resonance imaging and cognitive assessment within 15 months after stroke. PSCI was defined as impairment in ≥1 cognitive domains on neuropsychological assessment. Logistic regression analyses were performed to compare men to women, adjusted for study cohort, to obtain odds ratios for PSCI and individual cognitive domains. We also explored sensitivity and specificity of cognitive screening tools for detecting PSCI, according to sex (Mini-Mental State Examination, 4 cohorts, n=1814; Montreal Cognitive Assessment, 3 cohorts, n=278). RESULTS: PSCI was found in 51% of both women and men. Men had a lower risk of impairment of attention and executive functioning (men: odds ratio, 0.76 [95% CI, 0.61-0.96]), and language (men: odds ratio, 0.67 [95% CI, 0.45-0.85]), but a higher risk of verbal memory impairment (men: odds ratio, 1.43 [95% CI, 1.17-1.75]). The sensitivity of Mini-Mental State Examination (<25) for PSCI was higher for women (0.53) than for men (0.27; P=0.02), with a lower specificity for women (0.80) than men (0.96; P=0.01). Sensitivity and specificity of Montreal Cognitive Assessment (<26.) for PSCI was comparable between women and men (0.91 versus 0.86; P=0.62 and 0.29 versus 0.28; P=0.86, respectively). CONCLUSIONS: Sex was not associated with PSCI occurrence but affected domains differed between men and women. The latter may explain why sensitivity of the Mini-Mental State Examination for detecting PSCI was higher in women with a lower specificity compared with men. These sex differences need to be considered when screening for and diagnosing PSCI in clinical practice.


Assuntos
Disfunção Cognitiva , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Feminino , Masculino , AVC Isquêmico/complicações , Caracteres Sexuais , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/etiologia , Acidente Vascular Cerebral/epidemiologia , Função Executiva
4.
Stroke ; 54(12): 3021-3029, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37901947

RESUMO

BACKGROUND: White matter hyperintensities (WMH) are associated with cognitive dysfunction after ischemic stroke. Yet, uncertainty remains about affected domains, the role of other preexisting brain injury, and infarct types in the relation between WMH burden and poststroke cognition. We aimed to disentangle these factors in a large sample of patients with ischemic stroke from different cohorts. METHODS: We pooled and harmonized individual patient data (n=1568) from 9 cohorts, through the Meta VCI Map consortium (www.metavcimap.org). Included cohorts comprised patients with available magnetic resonance imaging and multidomain cognitive assessment <15 months poststroke. In this individual patient data meta-analysis, linear mixed models were used to determine the association between WMH volume and domain-specific cognitive functioning (Z scores; attention and executive functioning, processing speed, language and verbal memory) for the total sample and stratified by infarct type. Preexisting brain injury was accounted for in the multivariable models and all analyses were corrected for the study site as a random effect. RESULTS: In the total sample (67 years [SD, 11.5], 40% female), we found a dose-dependent inverse relationship between WMH volume and poststroke cognitive functioning across all 4 cognitive domains (coefficients ranging from -0.09 [SE, 0.04, P=0.01] for verbal memory to -0.19 [SE, 0.03, P<0.001] for attention and executive functioning). This relation was independent of acute infarct volume and the presence of lacunes and old infarcts. In stratified analyses, the relation between WMH volume and domain-specific functioning was also largely independent of infarct type. CONCLUSIONS: In patients with ischemic stroke, increasing WMH volume is independently associated with worse cognitive functioning across all major domains, regardless of old ischemic lesions and infarct type.


Assuntos
Lesões Encefálicas , AVC Isquêmico , Acidente Vascular Cerebral , Substância Branca , Humanos , Feminino , Masculino , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , AVC Isquêmico/complicações , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Cognição , Estudos de Coortes , Imageamento por Ressonância Magnética , Lesões Encefálicas/patologia , Infarto/patologia , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/patologia , Testes Neuropsicológicos
5.
Stroke ; 54(12): 3002-3011, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37942640

RESUMO

BACKGROUND: There is limited information on the delivery of acute stroke therapies and secondary preventive measures and clinical outcomes over time in young adults with acute ischemic stroke. This study investigated whether advances in these treatments improved outcomes in this population. METHODS: Using a prospective multicenter stroke registry in Korea, young adults (aged 18-50 years) with acute ischemic stroke hospitalized between 2008 and 2019 were identified. The observation period was divided into 4 epochs: 2008 to 2010, 2011 to 2013, 2014 to 2016, and 2017 to 2019. Secular trends for patient characteristics, treatments, and outcomes were analyzed. RESULTS: A total of 7050 eligible patients (mean age, 43.1; men, 71.9%) were registered. The mean age decreased from 43.6 to 42.9 years (Ptrend=0.01). Current smoking decreased, whereas obesity increased. Other risk factors remained unchanged. Intravenous thrombolysis and mechanical thrombectomy rates increased over time from 2008 to 2010 to 2017 to 2019 (9.5%-13.8% and 3.2%-9.2%, respectively; Ptrend<0.01). Door-to-needle time improved (Ptrend <.001), but onset-to-door and door-to-puncture times remained constant. Secondary prevention, including dual antiplatelets for noncardioembolic minor stroke (26.7%-47.0%), direct oral anticoagulants for atrial fibrillation (0.0%-56.2%), and statins for large artery atherosclerosis (76.1%-95.3%) increased (Ptrend<0.01). Outcome data were available from 2011. One-year mortality (2.5% in 2011-2013 and 2.3% in 2017-2019) and 3-month modified Rankin Scale scores 0 to 1 (68.3%-69.1%) and 0 to 2 (87.6%-86.2%) remained unchanged. The 1-year stroke recurrence rate increased (4.1%-5.5%; Ptrend=0.04), although the difference was not significant after adjusting for sex and age. CONCLUSIONS: Improvements in the delivery of acute stroke treatments did not necessarily lead to better outcomes in young adults with acute ischemic stroke over the past decade, indicating a need for further progress.


Assuntos
Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Masculino , Humanos , Adulto Jovem , Adulto , AVC Isquêmico/tratamento farmacológico , Isquemia Encefálica/epidemiologia , Isquemia Encefálica/terapia , Isquemia Encefálica/complicações , Estudos Prospectivos , Anticoagulantes/uso terapêutico , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/terapia , Acidente Vascular Cerebral/complicações , Resultado do Tratamento
6.
Arch Microbiol ; 200(1): 73-83, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28795230

RESUMO

Coagulase-negative staphylococci (CNS) are opportunistic pathogens that are currently emerging as causative agents of human disease. Though CNS are widespread in the clinic and food, their precise identification at species level is important. Here, using 16S rRNA sequencing, 55 staphylococcal isolates were identified as S. capitis, S. caprae, S. epidermidis, S. haemolyticus, S. pasteuri, S. saprophyticus, S. warneri, and S. xylosus. Although 16S rRNA sequencing is universally accepted as a standard for bacterial identification, the method did not effectively discriminate closely related species, and additional DNA sequencing was required. The divergence of the sodA gene sequence is higher than that of 16S rRNA. To devise a rapid and accurate identification method, sodA-specific primers were designed to demonstrate that species-specific multiplex polymerase chain reaction (PCR) can be used for the identification of CNS species. The accuracy of this method was higher than that of phenotypic identification; the method is simple and less time-consuming than 16S rRNA sequencing. Of the 55 CNS isolates, 92.72% were resistant to at least one antibiotic, and 60% were resistant to three or more antibiotics. CNS isolates produced diverse virulence-associated enzymes, including hemolysin (produced by 69.09% of the isolates), protease (65.45%), lipase (54.54%), lecithinase (36.36%), and DNase (29.09%); all isolates could form a biofilm. Because of the increasing pathogenic significance of CNS, the efficient multiplex PCR detection method developed in this study may contribute to studies for human health.


Assuntos
Técnicas de Tipagem Bacteriana/métodos , Coagulase/metabolismo , Reação em Cadeia da Polimerase Multiplex/métodos , Staphylococcus/isolamento & purificação , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Coagulase/genética , Primers do DNA/genética , Farmacorresistência Bacteriana , Humanos , RNA Ribossômico 16S/genética , Infecções Estafilocócicas/microbiologia , Staphylococcus/classificação , Staphylococcus/efeitos dos fármacos , Staphylococcus/genética
7.
Sensors (Basel) ; 18(1)2018 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-29351218

RESUMO

In this paper, we introduce a transparent fingerprint sensing system using a thin film transistor (TFT) sensor panel, based on a self-capacitive sensing scheme. An armorphousindium gallium zinc oxide (a-IGZO) TFT sensor array and associated custom Read-Out IC (ROIC) are implemented for the system. The sensor panel has a 200 × 200 pixel array and each pixel size is as small as 50 µm × 50 µm. The ROIC uses only eight analog front-end (AFE) amplifier stages along with a successive approximation analog-to-digital converter (SAR ADC). To get the fingerprint image data from the sensor array, the ROIC senses a capacitance, which is formed by a cover glass material between a human finger and an electrode of each pixel of the sensor array. Three methods are reviewed for estimating the self-capacitance. The measurement result demonstrates that the transparent fingerprint sensor system has an ability to differentiate a human finger's ridges and valleys through the fingerprint sensor array.

8.
Front Neurol ; 15: 1375609, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38817546

RESUMO

Background: Lipid-lowering therapies are mainstays in reducing recurrence after acute ischemic stroke (AIS). Evolocumab, a Proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitor, is a promising lipid-lowering agent known to decrease LDL cholesterol and mitigate vascular events alongside statins. However, its effects on the early functional outcomes post-mechanical thrombectomy (MT) remain unclear. This study aimed to assess the short-term effects and incidence of bleeding events after the early, off-label use of PCSK9 inhibitors in AIS patients undergoing MT. Methods: We retrospectively analyzed patients who had MT at a Regional Stroke Center from December 2018 to April 2023. Our primary outcome was discharge functional outcomes. Secondary outcomes included early neurologic deterioration (END), symptomatic intracerebral hemorrhage (sICH), 3-month functional outcomes, 3-month recurrence rate, and lipid profiles. Results: Of 261 patients (mean age 69.2 ± 11.7, men 42.9%), 42 were administered evolocumab peri-procedurally. While baseline characteristics were similar between the two groups, evolocumab group demonstrated improved discharge outcomes, with a lower mean NIHSS (8.8 ± 6.8 vs. 12.4 ± 9.8, p = 0.02) and a higher percentage of patients with discharge mRS ≤ 3 (52.4% vs. 35.6%, p = 0.041). The 3-month follow-up show a non-significant trend toward an improved outcome in the evolocumab group. Multivariable analysis indicated that evolocumab had a potential impact on favorable discharge outcomes (aOR 1.98[0.94-4.22] for mRS ≤ 3 and 0.47[0.27-0.84] for lower ordinal mRS). Notably, evolocuamb users exhibited fewer instances of END and sICH, although they do not reach statistical significance. Additionally, the evolocumab group demonstrated potential benefits in LDL cholesterol reduction over time. Conclusion: Early use of evolocumab in AIS patients undergoing MT appeared to be safe and associated with better early functional outcomes. The potential benefit of the PCSK9 inhibitor shown here warrants further prospective studies.

9.
J Stroke ; 26(1): 26-40, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38326705

RESUMO

Intracranial arterial disease (ICAD) is a heterogeneous condition characterized by distinct pathologies, including atherosclerosis. Advances in magnetic resonance technology have enabled the visualization of intracranial arteries using high-resolution vessel wall imaging (HR-VWI). This review summarizes the anatomical, embryological, and histological differences between the intracranial and extracranial arteries. Next, we review the heterogeneous pathophysiology of ICAD, including atherosclerosis, moyamoya or RNF213 spectrum disease, intracranial dissection, and vasculitis. We also discuss how advances in HR-VWI can be used to differentiate ICAD etiologies. We emphasize that one should consider clinical presentation and timing of imaging in the absence of pathology-radiology correlation data. Future research should focus on understanding the temporal profile of HR-VWI findings and developing quantitative interpretative approaches to improve the decision-making and management of ICAD.

10.
Neurointervention ; 19(1): 24-30, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38321887

RESUMO

PURPOSE: Cutting balloon-percutaneous transluminal angioplasty (CB-PTA) is a feasible treatment option for in-stent restenosis (ISR) after carotid artery stenting (CAS). However, the longterm durability and safety of CB-PTA for ISR after CAS have not been well established. MATERIALS AND METHODS: We retrospectively reviewed medical records of patients with ISR after CAS who had been treated with CB-PTA from 2012 to 2021 in our center. Detailed information of baseline characteristics, periprocedural and long-term outcomes, and follow-up imaging was collected. RESULTS: During 2012-2021, a total of 301 patients underwent CAS. Of which, CB-PTA was performed on 20 lesions exhibiting severe ISR in 18 patients following CAS. No patient had any history of receiving carotid endarterectomy or radiation therapy. These lesions were located at the cervical segment of the internal carotid artery (n=16), proximal external carotid artery (n=1), and distal common carotid artery (n=1). The median time interval between initial CAS and detection of ISR was 390 days (interquartile range 324-666 days). The follow-up period ranged from 9 months to 9 years with a median value of 21 months. Four patients (22.2%) were symptomatic. The average of stenotic degree before and after the procedure was 79.2% and 34.7%, respectively. Out of the 18 patients receiving CB-PTA, 16 (88.9%) did not require additional stenting, and 16 (88.9%) did not experience recurrent ISR during the follow-up period. Two patients who experienced recurrent ISR were successfully treated with CB-PTA and additional stenting. No periprocedural complication was observed in any case. CONCLUSION: Regarding favorable periprocedural and long-term outcomes in our single-center experience, CB-PTA was a feasible and safe option for the treatment of severe ISR after CAS.

11.
Int J Stroke ; 19(8): 916-924, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38651756

RESUMO

BACKGROUND: Post-stroke cognitive impairment (PSCI) occurs in up to 50% of stroke survivors. Presence of pre-existing vascular brain injury, in particular the extent of white matter hyperintensities (WMH), is associated with worse cognitive outcome after stroke, but the role of WMH location in this association is unclear. AIMS: We determined if WMH in strategic white matter tracts explain cognitive performance after stroke. METHODS: Individual patient data from nine ischemic stroke cohorts with magnetic resonance imaging (MRI) were harmonized through the Meta VCI Map consortium. The association between WMH volumes in strategic tracts and domain-specific cognitive functioning (attention and executive functioning, information processing speed, language and verbal memory) was assessed using linear mixed models and lasso regression. We used a hypothesis-driven design, primarily addressing four white matter tracts known to be strategic in memory clinic patients: the left and right anterior thalamic radiation, forceps major, and left inferior fronto-occipital fasciculus. RESULTS: The total study sample consisted of 1568 patients (39.9% female, mean age = 67.3 years). Total WMH volume was strongly related to cognitive performance on all four cognitive domains. WMH volume in the left anterior thalamic radiation was significantly associated with cognitive performance on attention and executive functioning and information processing speed and WMH volume in the forceps major with information processing speed. The multivariable lasso regression showed that these associations were independent of age, sex, education, and total infarct volume and had larger coefficients than total WMH volume. CONCLUSION: These results show tract-specific relations between WMH volume and cognitive performance after ischemic stroke, independent of total WMH volume. This implies that the concept of strategic lesions in PSCI extends beyond acute infarcts and also involves pre-existing WMH. DATA ACCESS STATEMENT: The Meta VCI Map consortium is dedicated to data sharing, following our guidelines.


Assuntos
Disfunção Cognitiva , Imageamento por Ressonância Magnética , Acidente Vascular Cerebral , Substância Branca , Humanos , Feminino , Masculino , Substância Branca/patologia , Substância Branca/diagnóstico por imagem , Idoso , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/patologia , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/psicologia , Acidente Vascular Cerebral/patologia , Pessoa de Meia-Idade , Testes Neuropsicológicos
12.
Front Neurol ; 14: 1230141, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37900609

RESUMO

Background and purpose: The angiotensin-converting enzyme (ACE) insertion (I)/deletion (D) polymorphism has been studied as a genetic candidate for cerebral small vessel disease (CSVD). However, no previous study has evaluated the relationship between the ACE I/D polymorphism and cerebral microbleed (CMB), an important CSVD marker. We evaluated the association between ACE I/D polymorphisms and 2-year changes in CMBs. Methods: The CHALLENGE (Comparison Study of Cilostazol and Aspirin on Changes in Volume of Cerebral Small Vessel Disease White Matter Changes) database was analyzed. Of 256 subjects, 186 participants who underwent a 2-year follow-up brain scan and ACE genotyping were included. Our analysis was conducted by dividing the ACE genotype into two groups (DD vs. ID/II) under the assumption of the recessive effects of the D allele. A linear mixed-effect model was used to compare the 2-year changes in the number of CMBs between the DD and combined ID/II genotypes. Results: Among 186 patients included in this study, 24 (12.9%) had the DD genotype, 91 (48.9%) had the ID genotype, and 71 (38.2%) had the II genotype. Baseline clinical characteristics and cerebral small vessel disease markers were not different between the two groups (DD vs. ID/II) except for the prevalence of hypertension (DD 66.7% vs. ID/II 84.6%; p = 0.04). A multivariate linear mixed-effects model showed that the DD carriers had a greater increase in total CMB counts than the ID/II carriers after adjusting for the baseline number of CMBs, age, sex, and hypertension (estimated mean of difference [standard error (SE)] = 1.33 [0.61]; p = 0.03). When we performed an analysis of cases divided into deep and lobar CMBs, only lobar CMBs were significantly different between the two groups (estimated mean of difference [SE] = 0.94 [0.42]; p = 0.02). Conclusion: The progression of CMBs over 2 years was greater in the ACE DD carriers compared with the combined II/ID carriers. The results of our study indicate a possible association between the ACE I/D polymorphism and CMB. A study with a larger sample size is needed to confirm this association.

13.
J Nanosci Nanotechnol ; 11(1): 725-9, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21446532

RESUMO

The widely tunable emissions of Zn(x)Cd(1-x)Se alloy quantum dots (QDs), which emit green to red wavelengths from 534 to 620 nm, are reported. Green-, yellow-, orange-, and red-emitting QDs were synthesized by varying a point of time for oleylamine (as a co-surfactant) addition and a Se precursor amount, and keeping a constant Zn/Cd precursor ratio. With reaction time the alloying and particle growth of the alloy QDs progressed simultaneously in the opposite direction in the variation of their band gap. However, the band gap energies of all QDs were observed to be gradually blue-shifted due to the slight dominance of alloying over the particle growth effect. The compositions of alloy QDs were estimated based on their sizes and band gap energies. Zn(x)Cd(1-x)Se core QDs were also overcoated with a ZnSe shell with a higher band gap to enhance their quantum yields.

14.
J Am Chem Soc ; 131(22): 7482-3, 2009 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-19489633

RESUMO

Reversible formation and dissolution of gold nanoparticles through turning on and off UV light was reported. Gold ions (Au(3+)) were reduced to monodispersed gold nanoparticles by UV irradiation from a mixture of comb-like poly(oxyethylene)s and a gold salt. The prepared gold nanoparticles dissolved to yield gold ions (Au(3+)) when the UV light was switched off. Such formation and dissolution could be repeated persistently by turning the UV light on and off repeatedly.

15.
Nanotechnology ; 20(49): 495602, 2009 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-19893149

RESUMO

Undoped, Tb(3+)- and Eu(3+)-doped ZnGa(2)O(4) colloidal nanocrystals were synthesized by a nonhydrolytic hot solution chemistry. Undoped nanocrystals exhibited an intrinsic blue emission peaking at 437 nm by self-activated transition. The emissions of Tb(3+)-and Eu(3+)-doped ZnGa(2)O(4) nanocrystals consisted of their own characteristic green and red line peaks ((5)D(4)-(7)F(j) transitions), respectively. Synthetic parameters such as activator concentration and reaction time were varied to investigate their effects on luminescent properties. Tb(3+)-doped colloidal nanocrystals synthesized for a short reaction time showed an unprecedented, exclusively green luminescence with the host blue emission effectively suppressed. On the other hand, the emission of Eu(3+)-doped ones was weak with the host emission persistently present regardless of reaction time.

16.
J Nanosci Nanotechnol ; 9(3): 2148-54, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19435094

RESUMO

Thin multi-walled carbon nanotubes (MWCNTs) were successfully synthesized by a rapid thermal chemical vapor deposition (RTCVD) method using a liquid catalyst. The growth of the thin MWCNTs was achieved by decomposition of C2H2 over Fe-Mo/MgO/citric acid directly at 700 degrees C for 30 min. Most thin MWCNTs, which had about 6 approximately 8 graphene layers, showed high purity (approximately 90%) and good crystallinity. Moreover, they showed homogenous morphology and uniform diameters. The average outer diameter of the thin MWCNTs was about 8 nm. The uniform diameter and good homogeneity of thin MWCNTs were mainly attributed to prevention of catalyst agglomeration at high temperature due to a short reaction time, and the high purity of thin MWCNTs was caused by suppression of the residual CNT growth after finishing a reaction in RTCVD process. Field emission properties of the thin MWCNTs were measured in a vacuum chamber at a pressure of less than 2 x 10(-7) Torr. The turn-on field was about 3.35 V/microm at the emission current density of 0.1 microA/cm2, and the emission current density was 2.5 mA/cm2 at an applied field of 6.7 V/microm. Particularly, the thin MWCNTs showed strong emission stability at emission current density of 0.8 mA/cm2 for 20 h.

17.
Integr Med Res ; 8(1): 1-7, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30596012

RESUMO

BACKGROUND: Prehypertension and hypertension are associated with cardiovascular disease, ischemic heart disease, and stroke morbidity. The purpose of this study is to evaluate the effectiveness and safety of moxibustion in patients with prehypertension or hypertension. METHODS: Forty-five subjects with prehypertension or stage I hypertension were randomized into three groups: moxibustion treatment group A (2 sessions/week for 4 weeks), moxibustion treatment group B (3 sessions/week for 4 weeks), and control group (nontreated group). The primary outcome measure was the change in blood pressure after 4 weeks of treatment. Safety was assessed at every visit. RESULTS: There were no significant differences in systolic blood pressure (SBP) or diastolic blood pressure (DBP) among three groups after 4 weeks of treatment (p = 0.4798 and p = 0.3252, respectively). In treatment group B, there was a significant decrease in SBP and DBP from baseline to 4 weeks of treatment (mean difference (MD) -9.55; p = 0.0225, MD -7.55; p = 0.0098, respectively). There were no significant differences among groups in secondary outcome measures after 4 weeks of treatment. Six adverse events (AEs) in the treatment group A and 12 AEs in the treatment group B occurred related to the moxibustion treatment. CONCLUSION: In conclusion, the results of this study show that moxibustion (3 sessions/week for 4 weeks) might lower blood pressure in patients with prehypertension or stage I hypertension and treatment frequency might affect effectiveness of moxibustion in BP regulation. Further randomized controlled trials with a large sample size on prehypertension and hypertension should be conducted. TRIAL REGISTRATION: This study was registered with the 'Clinical Research Information Service (CRIS)', Republic of Korea (KCT0000469), and the protocol for this study was presented orally at the 15th International Council of Medical Acupuncture and Related Techniques (ICMART) in Athens, 25-27 May 2012.

18.
Medicine (Baltimore) ; 98(7): e14508, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30762782

RESUMO

BACKGROUND: The sequelae of Bell's palsy cause critical problem in facial appearance, as well as social and psychological problems in the patient's life. The aim of the present study is to establish clinical evidence of thread-embedding acupuncture (TEA) in the treatment of sequelae of Bell's palsy. METHOD/DESIGN: This is a patient-assessor blinded, randomized, sham-controlled trial with two parallel arms. Fifty-six patients aged 19-65 years, who have experienced sequelae of Bell's palsy for >3 months, will be recruited and screened using the eligibility criteria. After screening, they will be randomly allocated to a TEA group or a sham TEA (STEA) group. Both groups will receive TEA or STEA treatment on ten predefined acupoints once a week for 8 weeks. Additionally, both groups will receive the same acupuncture treatment twice a week for 8 weeks as a concurrent treatment. Changes in the Facial Disability Index over 8 weeks will be assessed as the primary outcome. Furthermore, the House-Brackmann Grade, Facial Nerve Grading System 2.0, Sunnybrook Facial Grading System, facial stiffness score, lip mobility score, and treatment satisfaction score will be measured and analyzed as secondary outcomes. All outcomes will be assessed at baseline and at 4 and 8 weeks after screening. DISCUSSION: The results from this trial will help establish clinical evidence regarding the efficacy and safety of TEA in the treatment of patients with sequelae of Bell's palsy. TRIAL REGISTRATION NUMBER: KCT0002557 (Clinical Research Information Service of the Republic of Korea).


Assuntos
Terapia por Acupuntura/métodos , Paralisia de Bell/terapia , Projetos de Pesquisa , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Índice de Gravidade de Doença , Método Simples-Cego , Adulto Jovem
19.
Sci Total Environ ; 691: 858-867, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31326809

RESUMO

Occurrence of typhoons accompanied by heavy precipitation has increased for the past 40 years in northeast Asia. To elucidate the impact of three consecutive typhoon-induced heavy rainfall events and resultant freshwater runoff on the partitioning of organic carbon (Corg) oxidation and nutrient dynamics, we investigated the geochemical constituents, the rate of anaerobic Corg oxidation, sulfate reduction (SR), iron reduction (FeR) and P speciation in the intertidal mud flat of the Han River estuary, Yellow Sea. Corg oxidation by SR and FeR and their metabolic products (∑CO2, NH4+, H2S, Fe2+) decreased significantly (P < 0.05) during and immediately after the heavy rainfall. Additional mesocosm experiments demonstrated that potential N2 production rates increased up to 2.4 times with increased nitrate concentrations during freshwater runoff. The results suggest that denitrification becomes a significant Corg oxidation pathway substituting for SR during high-nitrate freshwater runoff, which may remove substantial portion of the N introduced into the estuary. P speciation analysis further revealed that the concentrations of iron bound P decreased by 2.2 fold during the heavy rainfall compared to that measured before the rainfall. The results suggest that an excess supply of riverine Si keeps P from binding to Fe, thereby stimulating P release. Taking projections of enhanced rainfall events in the future into account, our results suggest that the intensified storm events and resultant riverine runoff induces a shift of Corg oxidation pathways in the sediments, which ultimately alters C-N-P-S-Fe dynamics and may deepen N-limiting conditions in coastal ecosystems of the Yellow Sea.

20.
J Nanosci Nanotechnol ; 8(10): 5212-5, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19198423

RESUMO

A method for one-pot size-controlled synthesis of silver nanoparticles is proposed and described. The synthesis is based on the reduction of silver-alkanethiolates complexes having highly ordered supramolecular structures through electron beam irradiation in transmission electron microscope (TEM). The method allows synthesis of silver nanoparticles of diameters between 1.9 nm and 5.9 nm. Different diameters within this range can be selected for by varying the acceleration voltage in TEM, alkyl chain length, and structure of the silver-alkanethiolates complexes.


Assuntos
Nanopartículas Metálicas , Microscopia Eletrônica de Transmissão/métodos , Prata
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