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BACKGROUND: Anshen Buxin Liuwei pill (ABLP) is a Mongolian medicinal formula that is composed of six medicinal materials: the Mongolian medicine Bos taurus domesticus Gmelin, Choerospondias axillaris (Roxb.) Burtt et Hill, Myristica fragrans Houtt., Eugenia caryophµllata Thunb., Aucklandia lappa Decne., and Liqui dambar formosana Hance. ABLP is considered to have a therapeutic effect on symptoms such as coronary heart disease, angina pectoris, arrhythmia, depression and irritability, palpitation, and shortness of breath. METHODS: H9c2 cardiomyocytes were used to construct a hypoxia/reoxygenation (HR) injury model. CCK-8 assay and Annexin V-FITC cell apoptosis assays were used for cell viability and cell apoptosis determination. The LDH, SOD, MDA, CAT, CK, GSH-Px, Na+-K+-ATPase, and Ca2+-ATPase activities in cells were determined to assess the protective effects of ABLP. The mRNA levels of Sirtuin3 (Sirt3) and Cytochrome C (Cytc) in H9c2 cells were determined by quantitative real-time PCR. RESULTS: The results indicate that HR-treated cells began to shrink from the spindle in an irregular shape with some floated in the medium. By increasing the therapeutic dose of ABLP (5, 25, and 50 µg/mL), the cells gradually reconverted in a concentration-dependent manner. The release of CK in HR-treated cells was significantly increased, indicating that ABLP exerts a protective effect in H9c2 cells against HR injury and can improve mitochondrial energy metabolism and mitochondrial function integrity. The present study scrutinized the cardioprotective effects of ABLP against HR-induced H9c2 cell injury through antioxidant and mitochondrial pathways. CONCLUSIONS: ABLP could be a promising therapeutic drug for the treatment of myocardial ischemic cardiovascular disease. The results will provide reasonable information for the clinical use of ABLP.
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Medicina Tradicional do Leste Asiático/métodos , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miócitos Cardíacos/metabolismo , Animais , Apoptose/efeitos dos fármacos , Hipóxia Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Citocromos c/metabolismo , Hipóxia/metabolismo , Mitocôndrias/metabolismo , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Miócitos Cardíacos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Ratos , Sirtuína 3/metabolismoRESUMO
Due to the global infection problem caused by the abuse of antibiotics, the preparation of novel antibacterial nanomaterials is a key and basic requirement for applications in antibacterial and bacterial imaging fields. This paper reports the one-step preparation of blue-green-emitting carbon dots (CDs) under low temperature (80 °C) with glucose as the carbon source, citric acid as the dehydrating agent, and polyethyleneimine as the nitrogen source. Through inhibition zone tests and minimum inhibitory concentration (MIC) experiments, the inhibitory abilities of prepared CDs against various microorganisms, including gram-positive bacteria, gram-negative bacteria and fungi, were compared. It is worth mentioning that the MIC of CDs against Staphylococcus aureus reaches 4.7 µg ml-1, and the CDs exhibit excellent biocompatibility. Moreover, studies on visual-treatment therapy, in which infection treatment can be performed at the same time as bacterial imaging, with the prepared functional antibacterial CDs based on fluorescence confocal imaging would be beneficial to their promising future in medical and biological fields.
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Antibacterianos/farmacologia , Corantes Fluorescentes/química , Testes de Sensibilidade Microbiana/métodos , Imagem Molecular/métodos , Pontos Quânticos/química , Linhagem Celular , Temperatura Baixa , Corantes Fluorescentes/toxicidade , Humanos , Pontos Quânticos/toxicidade , Staphylococcus aureus/efeitos dos fármacosRESUMO
BACKGROUND: Guangzhou reported its first laboratory-confirmed case of influenza A (H7N9) on January 10, 2014. A total of 25 cases were reported from the first wave of the epidemic until April 8, 2014. The fatality rate was much higher than in previous reports. The objective of the current work was to describe the clinical and epidemiological characteristics of A (H7N9) patients in Guangzhou and explore possible reasons for the high fatality rate. METHODS: Clinical and epidemiological information regarding A (H7N9) cases in Guangzhou was collected through review of medical records and field research. Data regarding clinical and laboratory features, treatment, and outcomes were extracted. RESULTS: Of the 25 patients, 84 % (21/25) had one or more underlying diseases. Fifteen patients (60.0 %) developed moderate to severe acute respiratory distress syndrome (ARDS), and 14 (56 %) died of the ARDS or multiorgan failure. Patients with longer delay between onset of illness and initiation of oseltamivir treatment were more likely to develop ARDS. Elevated C-creative protein, aspartate aminotransferase, creatine kinase, and lymphocytopenia predicted a higher risk of developing ARDS. CONCLUSIONS: The presence of underlying diseases and clinical complications predicted poor clinical outcome. Early oseltamivir treatment was associated with a reduced risk of developing ARDS.
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Subtipo H7N9 do Vírus da Influenza A/patogenicidade , Influenza Humana/etiologia , Influenza Humana/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antivirais/uso terapêutico , Criança , Pré-Escolar , China/epidemiologia , Feminino , Humanos , Influenza Humana/epidemiologia , Masculino , Pessoa de Meia-Idade , Oseltamivir/uso terapêutico , Síndrome do Desconforto Respiratório/tratamento farmacológico , Estudos Retrospectivos , Síndrome Respiratória Aguda Grave/epidemiologia , Adulto JovemRESUMO
Targeted surveillance for influenza A(H7N9) identified 24 cases of infection with this virus in Guangzhou, China, during April 1, 2013-March 7, 2014. The spectrum of illness ranged from severe pneumonia to asymptomatic infection. Epidemiologic findings for 2 family clusters of infection highlight the importance of rigorous close contact monitoring.
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Subtipo H7N9 do Vírus da Influenza A , Influenza Humana/diagnóstico , Influenza Humana/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , China/epidemiologia , Surtos de Doenças , Feminino , História do Século XXI , Humanos , Lactente , Recém-Nascido , Subtipo H7N9 do Vírus da Influenza A/genética , Subtipo H7N9 do Vírus da Influenza A/isolamento & purificação , Influenza Humana/história , Influenza Humana/microbiologia , Masculino , Pessoa de Meia-Idade , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , Vigilância da População , Fatores de Risco , Índice de Gravidade de Doença , Adulto JovemRESUMO
Hand, foot and mouth disease (HFMD) is a contagious viral illness that commonly affects infants and children. The underlying risk factors have not yet been systematically examined. This study analyzed the short-term effects of meteorological factors on children HFMD in Guangzhou, China. Daily count of HFMD among children younger than 15 years and meteorological variables from 2009 to 2011 were collected to construct the time series. A generalized additive model was applied to estimate the effects of meteorological factors on HFMD occurrence, after adjusting for long-term trend, seasonal trend, day of week, and public holidays. A negative association between temperature and children HFMD occurrence was observed at lag days 1-3, with the relative risk (RR) for a 1 °C increase on lag day 2 being 0.983 (95% confidence intervals (CI) 0.977 to 0.989); positive effect was found for temperature at lag days 5-9, with the highest effect at lag day 6 (RR = 1.014, 95% CI 1.006 to 1.023). Higher humidity was associated with increased HFMD at lag days 3-10, with the highest effect at lag day 8 (RR = 1.009 for 1% increase in relative humidity, 95% CI 1.007 to 1.010). And we also observed significant positive effect for rainfall at lag days 4 and 8 (RR = 1.001, 95% CI 1.000 to 1.002) for 1-mm increase. Subgroup analyses showed that the positive effects of temperature were more pronounced among younger children. This study suggests that meteorological factors might be important predictors of children HFMD occurrence in Guangzhou.
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Doença de Mão, Pé e Boca/epidemiologia , Tempo (Meteorologia) , Adolescente , Criança , Pré-Escolar , China/epidemiologia , Feminino , Doença de Mão, Pé e Boca/transmissão , Humanos , Lactente , Recém-Nascido , Masculino , RiscoRESUMO
The sensitive detection of foodborne pathogenic and rapid antibiotic susceptibility testing (AST) is of great significance. This paper reports the enzyme-triggered in situ synthesis of yellow emitting silicon nanoparticles (SiNPs) and the detection of Escherichia coli (E. coli) O157:H7 in food samples and the rapid AST. The rapid counting of E. coli O157:H7 has been achieved through direct visual observation, equipment detection, and smartphone digitalization. A simple detection platform based on smartphone senses and cotton swabs has been established. Meanwhile, rapid AST based on enzyme-catalyzed SiNPs can intuitively obtain colorimetric samples. This paper established a system for bacterial enzyme-triggered in situ synthesis of SiNPs, with high responsiveness, luminescence ratio, and specificity. The detection limit for E. coli O157:H7 can reach 100 CFU/mL during 5 h, and the recovery efficiency ranges from 90.14% to 110.16%, which makes it a promising strategy for the rapid detection of E. coli O157:H7 and AST.
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Escherichia coli O157 , Nanopartículas , Silício , beta-Galactosidase , Escherichia coli O157/efeitos dos fármacos , Escherichia coli O157/isolamento & purificação , Nanopartículas/química , Silício/química , Silício/farmacologia , beta-Galactosidase/metabolismo , beta-Galactosidase/química , Testes de Sensibilidade Microbiana , Contaminação de Alimentos/análise , Colorimetria , Antibacterianos/farmacologia , Antibacterianos/química , Microbiologia de AlimentosRESUMO
The carbon dots (CDs) with excellent optical properties and their hydrogel complex are of great significance in biomedicine, healthcare and biochemical detection fields. This paper reports the preparation of green-emitting CDs (MA-CDs) through one-step hydrothermal route with citric acid as reducing agent, L-malic acid as carbon source and N-(2-hydroxyethyl)ethylenediamine as nitrogen source. To expand its application in biology, MA-CDs were coupled with vancomycin to obtain multifunctional CDs (VMA-CDs). The prepared VMA-CDs exhibit selective antibacterial behavior to Gram-positive bacteria, and it could be used as a fluorescent probe to selectively label Staphylococcus aureus (S. aureus). Moreover, thanks to the excellent optical properties of VMA-CDs, it has been used as a fluorescent sensor to detect Au3+ with detection range of 6.50 nM-21.93 µM and detection limit 3.98 nM. By introducing the fluorescence of CDs as the reference signal, and VMA-CDs as a response signal, the hydrogel (V-SP) was prepared and realized the detection of Au3+ in microfluidics with assistance of a smartphone to collect and analyze data.
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Hidrogéis , Pontos Quânticos , Pontos Quânticos/química , Carbono/química , Staphylococcus aureus , Antibacterianos/farmacologia , Corantes Fluorescentes/química , Nitrogênio/química , Espectrometria de FluorescênciaRESUMO
Ultraviolet (UV) light and foodborne pathogenic bacteriais are an important risk to the environment's safety. They endanger human health, and also lead to outbreaks of infectious disease, posing great threats to global public health security, national economy, and social stability. The appearance of carbon dot (CD) nanozymes offers a new perspective to solve the problems of detection of UV light and pathogenic bacteria in environment. This paper reports the preparation of CDs with dual enzyme-like activities (superoxide dismutase activity and UV-induced oxidase activity). The product can catalyze the oxidation of the substrate 3, 3', 5, 5'-tetramethylbenzidine (TMB) under UV light (365 nm) to achieve rapid color development. Based on the excellent fluorescence properties of CDs, the colorimetric-fluorescence dual-channel real-time detection of UVA dose was realized, the mechanism underlying the catalytic oxidation of TMB by UV-induced oxidase CDs was also investigated. Furthermore, a portable CDs-TMB-PA hydrogel was prepared which could realize the real-time monitoring of UV in outdoor environment with the assistance of smartphone. Based on the pH dependency of the CD nanozymes and specific glycolytic response of the pathogenic bacteria Escherichia coli (E. coli) O157:H7, the direct, simple, quick, and sensitive typing and detection have been realized. This research offers new perspectives for studying CD nanozymes and their applications in UV and bacterial detection, demonstrating the remarkable potential of CD nanozymes in detecting environmental hazards.
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Escherichia coli O157 , Oxirredutases , Humanos , Carbono , Catálise , Bactérias , Técnicas de Tipagem BacterianaRESUMO
OBJECTIVES: To compare the iatrogenic radial nerve injury (iRNI) rate of different implant (plate vs. intramedullary nail) and surgical approaches during humeral shaft fracture surgery. METHODS: The online PubMed database was used to search for articles describing iRNI after humeral fracture with a publication date from Jan 2000 to October 2023. The following types of articles were selected: (1) case series associating with adult humeral shaft fracture, preoperative radial nerve continuity, non-pathological fracture and non-periprosthetic fracture; (2) involving humeral shaft (OTA/AO 12) fractures. Articles where we were unable to judge surgical approach or fracture pattern (OTA/AO 12) were excluded. The data were analyzed by SPSS 27.0 and Chi-square test was performed to identify incidence of iRNI associated with different implant and surgical approaches. RESULTS: Fifty-four articles with 5063 cases were included, with 3510 cases of the plate, 830 cases of intramedullary nail and 723 cases of uncertain internal fixation. The incidences of iRNI with plate and intramedullary nail were 5.95% (209/3510) and 2.77% (23/830) (p < 0.05). And iRNI incidences of different surgical approaches were 3.7% (3/82) for deltopectoral approach, 5.74% (76/1323) for anterolateral approach, 13.54% (26/192) for lateral approach and 6.68% (50/749) for posterior approach. The iRNI rates were 0.00% (0/33) for anteromedial MIPO, 2.67% (10/374) for anterolateral MIPO and 5.40% (2/37) for posterior MIPO (p > 0.05). The iRNI rates were 2.87% (21/732) for anterograde intramedullary nail and 2.04% (2/98) for retrograde intramedullary nail (p > 0.05). In humeral bone nonunion surgery, the rate of iRNI was 15.00% (9/60) for anterolateral approach, 16.7% (2/12) for lateral approach and 18.2% (6/33) for posterior approach (p > 0.05). CONCLUSION: Intramedullary nailing is the preferred method of internal fixation for humeral shaft fractures that has the lowest rate of iRNI. Compared with anterolateral and posterior approaches, the lateral surgical approach had a higher incidence of iRNI. The rate of iRNI in MIPO was lower than that in open reduction and internal fixation. LEVEL OF EVIDENCE: Level IV.
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Fixação Intramedular de Fraturas , Fraturas do Úmero , Doença Iatrogênica , Nervo Radial , Humanos , Fraturas do Úmero/cirurgia , Nervo Radial/lesões , Nervo Radial/cirurgia , Fixação Intramedular de Fraturas/efeitos adversos , Fixação Intramedular de Fraturas/métodos , Placas Ósseas/efeitos adversos , Fixação Interna de Fraturas/métodos , Fixação Interna de Fraturas/efeitos adversos , Pinos Ortopédicos/efeitos adversos , IncidênciaRESUMO
Global COVID-19 vaccination programs effectively contained the fast spread of SARS-CoV-2. Characterizing the immunity status of returned populations will favor understanding the achievement of herd immunity and long-term management of COVID-19 in China. Individuals were recruited from 7 quarantine stations in Guangzhou, China. Blood and throat swab specimens were collected from participants, and their immunity status was determined through competitive ELISA, microneutralization assay and enzyme-linked FluoroSpot assay. A total of 272 subjects were involved in the questionnaire survey, of whom 235 (86.4%) were returning Chinese individuals and 37 (13.6%) were foreigners. Blood and throat swab specimens were collected from 108 returning Chinese individuals. Neutralizing antibodies against SARS-CoV-2 were detected in ~90% of returning Chinese individuals, either in the primary or the homologous and heterologous booster vaccination group. The serum NAb titers were significantly decreased against SARS-CoV-2 Omicron BA.5, BF.7, BQ.1 and XBB.1 compared with the prototype virus. However, memory T-cell responses, including specific IFN-γ and IL-2 responses, were not different in either group. Smoking, alcohol consumption, SARS-CoV-2 infection, COVID-19 vaccination, and the time interval between last vaccination and sampling were independent influencing factors for NAb titers against prototype SARS-CoV-2 and variants of concern. The vaccine dose was the unique common influencing factor for Omicron subvariants. Enhanced immunity against SARS-CoV-2 was established in returning Chinese individuals who were exposed to reinfection and vaccination. Domestic residents will benefit from booster homologous or heterologous COVID-19 vaccination after reopening of China, which is also useful against breakthrough infection.
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COVID-19 , SARS-CoV-2 , Humanos , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Anticorpos Neutralizantes , China/epidemiologiaRESUMO
OBJECTIVE: To investigate the epidemic characteristics and pathogenic spectrum of community acquired pneumonia (CAP) in Guangzhou from 2009 to 2012. METHOD: 14 major comprehensive hospitals were selected from 11 districts as sentinel hospitals for CAP cases surveillance, including 18 982 223 in total during the 4 years. The characteristics of pathogenic spectrum of CAP were stratified and analyzed by year, age and season. RESULTS: 18 982 223 cases were included in the surveillance from year 2009 to 2012, in which 56 618 cases were CAP. The number of CAP cases increased from 8677 in year 2009 to 19 947 in year 2012 in Guangzhou; while the percentage of visits for CAP raised from 0.22% (8677/3 893 800) to 0.41% (19 947/4 839 766). The difference showed statistical significance (χ(2) = 2693.00, P < 0.05). Among the hospitalized CAP cases, 66.05% (10 954/16 585) were aged ≤ 5 years old or > 66 years old. The percentage of cases infected by a single pathogen was 88.11% (14 613/16 585), while co-infected cases accounted for 4.17% (691/16 585). Bacteria accounted for the largest proportion of 65.25% (10 821/16 585) as a single pathogen, followed by mycoplasma 13.54% (2245/16 585), virus 9.01% (1494/16 585) and chlamydia 0.32% (53/16 585). The proportion of virus infection was increasing from 4.74% to 11.64%. The difference showed statistical significance (χ(2) = 135.32, P < 0.05). Bacteria infection was the leading causes for CAP cases in all age groups; however the percentage increased with the increasing of ages. The rate of bacterial infection was increased from 48.35% (2993/6191) among children aged ≤ 5 years old to 81.31% (3873/4763) among adults aged over 65 years (χ(2) = 1632.00, P < 0.05). The rate of atypical pathogens (mycoplasma, chlamydia) for children ( ≤ 15 years old) (25.99%, 1805/6945) was higher than that for adults aged ≥ 16 years old (5.12%, 494/9640) (χ(2) = 2.11, P < 0.05). The effect from season on the pathogenic spectrum was not observed.433 hospitalized CAP cases were dead from 2009 to 2012. Case fatality rate was highest among people aged over 65 years old (4.70%, 224/4763) and lowest among children aged between 6 to 15 years old (0.27%, 2/754). CONCLUSION: The incidence of community acquired pneumonia was rising in Guangzhou from 2009 to 2012. Bacteria was the dominant pathogen. Children and old people were the high-risk population of community acquired pneumonia; while co-infection was still at low level.
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Infecções Comunitárias Adquiridas/epidemiologia , Pneumonia/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , China/epidemiologia , Infecções Comunitárias Adquiridas/microbiologia , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Pneumonia/microbiologia , Vigilância de Evento Sentinela , Adulto JovemRESUMO
The preparation of functional long-wavelength-emitting nanomaterials and the researches on their applications in antibacterial and antibiofilm fields have important significance. This paper reports the preparation of yellow-green-fluorescent and high- quantum yield carbon dots (4-ACDs) with 4-aminosalicylic acid and polyethylene imine as raw materials through one-step route, and the impacts of raw material structure and the reaction conditions upon the optical properties of the products have been investigated. 4-ACDs exhibit excellent broad-spectrum antibacterial activity, and their good biocompatibility ensures them as ideal fluorescent nano-probe for cell imaging. However, 4-ACDs could not effectively eliminate the biofilm of Staphylococcus aureus (S. aureus). CDs-LZM complex was prepared through the coupling between 4-ACDs and lysozyme (LZM) and the complex showed strong antibacterial activity against Gram-positive bacteria, particularly with MIC against S. aureus at 5 µg mL-1. Besides, CDs-LZM showed excellent ability against the biofilm of S. aureus. At the concentration of 60 µg mL-1, its inhibition rate against the growth of biofilm was 86 %, and elimination rate against biofilm reached 76 %. CDs-LZM exhibited obvious antibiofilm ability through removing extracellular matrix of biofilm, greatly reducing the thickness of biofilm under confocal microscopy. The application of novel long-wavelength-emitting nanomaterial in eliminating pathogenic bacteria is of great significance.
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Pontos Quânticos , Infecções Estafilocócicas , Humanos , Staphylococcus aureus , Carbono/química , Muramidase/farmacologia , Antibacterianos/farmacologia , Biofilmes , Bactérias , Pontos Quânticos/química , Corantes Fluorescentes/químicaRESUMO
To avoid risk, spacecraft docking technologies can transport batches of different astronauts or cargoes to a space station. Before now, spacecraft-docking multicarrier/multidrug delivery systems have not been reported on. Herein, inspired by spacecraft docking technology, a novel system including two different docking units, one made of polyamide (PAAM) and on of polyacrylic acid (PAAC), grafted respectively onto polyethersulfone (PES) microcapsules, is designed, based on intermolecular hydrogen bonds in aqueous solution. VB12 and vancomycin hydrochloride were chosen as the release drugs. The release results show that the docking system is perfect, and has a good responsiveness to temperature when the grafting ratio of PES-g-PAAM and PES-g-PAAC is close to 1:1. Below 25 °C, this system exhibited an "off" effect because the polymer chains on the microcapsule's surface produced intermolecular hydrogen bonds. Above 25 °C, when the hydrogen bonds were broken, the microcapsules separated from each other, and the system exhibited an "on" state. The results provide valuable guidance for improving the feasibility of multicarrier/multidrug delivery systems.
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BACKGROUND: The re-emergence of dengue virus 4 (DENV-4) has become a public health concern in South America, Southeast Asia and South Asia. However, it has not been known to have caused a local outbreak in China for the past 20 years. The purpose of this study was to elucidate the epidemiology of one local community outbreak caused by DENV-4 in Guangzhou city, China, in 2010; and to determine the molecular characteristics of the genotype II virus involved. CASE PRESENTATIONS: During September and October of 2010, one imported case, a Guangzhou resident who travelled back from Thailand, resulted in 18 secondary autochthonous cases in Guangzhou City, with an incidence rate of 5.53 per 10,000 residents. In indigenous cases, 14 serum samples tested positive for IgM against DENV and 7 for IgG from a total of 15 submitted serum samples, accompanied by 5 DENV-4 isolates. With identical envelope gene nucleotide sequences, the two isolates (D10168-GZ from the imported index case and Guangzhou 10660 from the first isolate in the autochthonous cases) were grouped into DENV-4 genotype II after comparison to 32 previous DENV-4 isolates from GenBank that originated from different areas. CONCLUSIONS: Based on epidemiological and phylogenetic analyses, the outbreak, which was absent for 20 years after the DENV-4 genotype I outbreak in 1990, was confirmed as DENV-4 genotype II and initially traced to the imported index case, a Guangzhou resident who travelled back from Thailand.
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Vírus da Dengue/classificação , Vírus da Dengue/genética , Dengue/epidemiologia , Dengue/virologia , Surtos de Doenças , RNA Viral/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , China/epidemiologia , Análise por Conglomerados , Busca de Comunicante , Vírus da Dengue/isolamento & purificação , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Filogenia , Tailândia , Viagem , Adulto JovemRESUMO
The studies on the preparation of high-quality and long-wavelength-emitting silicon quantum dots and their application in biochemical detections have attracted increasing interests from researchers. In particular, the exploration of the effect of SiQDs and their complex in antibacterial and inhibition of biofilm areas, is of great significance to human health. This paper reports the fast synthesis of green-fluorescent SiQDs (TC-SiQDs, QYs=25%, Em=520 nm) with the synergistic effect of thiourea and catechol through microwave-assisted one-step hydrothermal route. Based on internal filtering effect, TC-SiQDs were then successfully employed as selective probes to detect vitamin B12, with detection range at 0.05-30 µM and limit of detection at 50 nM. Thanks to the excellent biocompatibility and fluorescence property of TC-SiQDs, they have been applied in bacterial imaging. The prepared TC-SiQDs also exhibit certain antibacterial ability with their minimum inhibitory concentration (MIC) against Staphylococcus aureus (S. aureus) at 250 µg/mL, but their inhibitory ability is effective to the growth of S. aureus biofilm only when the concentration reaches 1.3 mg/mL. TC-SiQDs-lysozyme complex were prepared, based on the effects of singlet oxygen, charge effect and lysozyme hydrolysis of peptidoglycan in the cell wall, the complex exhibits high inhibiting activity with MIC against S. aureus at 10 µg/mL and exhibits superior inhibition activity against S. aureus biofilm at a concentration of only 62.5 µg/mL. This paper provides good theoretical and practical basis for the synthesis of long-wavelength emission and ultra-bright SiQDs and their applications in detection, antibacterial and biofilm growth inhibition, and other biomedical fields.
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Antibacterianos , Pontos Quânticos , Antibacterianos/química , Antibacterianos/farmacologia , Muramidase , Pontos Quânticos/química , Silício/química , Staphylococcus aureus/efeitos dos fármacosRESUMO
Introduction: Pathogenic bacteria, especially the ones with highly organized, systematic aggregating bacteria biofilm, would cause great harm to human health. The development of highly efficient antibacterial and antibiofilm functional fluorescent nanomaterial would be of great significance. Methods: This paper reports the preparation of a series of antibacterial functional carbon dots (CDs) with chitosan (CS) and its derivatives as raw materials through one-step route, and the impact of various experiment parameters upon the optical properties and the antibacterial abilities have been explored, including the structures of the raw materials, excipients, and solvents. Results: The CDs prepared by quaternary ammonium salt of chitosan (QCS) and ethylenediamine (EDA) exhibit multiple antibacterial effects through membrane breaking, DNA and protein destroying, and the production of singlet oxygen. The CDs showed excellent broad-spectrum inhibitory activity against a variety of bacteria (Gram-positive and negative bacteria), in particular, to the biofilm of Staphylococcus aureus with minimum inhibitory concentration at 10 µg/mL, showing great potential in killing bacteria and biofilms. The biocompatibility experiments proved that QCS-EDA-CDs are non-toxic to human normal hepatocytes and have low haemolytic effect. Furthermore, the prepared QCS-EDA-CDs have been successfully used in bacterial and biofilm imaging thanks to their excellent optical properties. Conclusion: This paper explored the preparation and application of functional CDs, which can be used as the visual probe and therapeutic agents in the treatment of infections caused by bacteria and biofilm.
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Quitosana , Staphylococcus aureus , Antibacterianos/química , Antibacterianos/farmacologia , Biofilmes , Carbono/química , Carbono/farmacologia , Quitosana/química , Quitosana/farmacologia , HumanosRESUMO
In this paper, we report a microcapsule embedded PNIPAN in P (TPC-EDA) shell and it can be regarded as an interpenetrating polymer network (IPN) structure, which can accelerate the penetration of oily substances at a certain temperature, and the microcapsules are highly monodisperse and dimensionally reproducible. The proposed microcapsules were fabricated in a three-step process. The first step was the optimization of the conditions for preparing oil in water emulsions by microfluidic device. In the second step, monodisperse polyethylene terephthaloyl-ethylenediamine (P(TPC-EDA)) microcapsules were prepared by interfacial polymerization. In the third step, the final microcapsules with poly(N-isopropylacrylamide) (PNIPAM)-based interpenetrating polymer network (IPN) structure in P(TPC-EDA) shells were finished by free radical polymerization. We conducted careful data analysis on the size of the emulsion prepared by microfluidic technology and used a very intuitive functional relationship to show the production characteristics of microfluidics, which is rarely seen in other literatures. The results show that when the IPN-structured system swelled for 6 h, the adsorption capacity of kerosene was the largest, which was promising for water-oil separation or extraction and separation of hydrophobic drugs. Because we used microfluidic technology, the products obtained have good monodispersity and are expected to be produced in large quantities in industry.
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OBJECTIVE: To investigate the relationship among dietary iron intake, body iron overload and risk of metabolic syndrome. METHODS: 87 MS patients and 102 matched healthy adults were recruited. Fasting blood samples were collected and assayed for serum ferritin (SF), serum iron (SI), total iron-binding capacity (TIBC), fasting insulin (FIN), fasting blood glucose (FBG), MDA, SOD and NF-kappaB. The data of dietary intake were collected by using a 24-hour dietary recall method for 7 consecutive days by trained interviewers. RESULTS: Total dietary iron intake, iron intake from animal source, serum MDA and NF-kappaB in MS group was significantly higher than that in the control group. SF, SI, siderophilin saturation and serum SOD in MS group was lower than that in the control group. There is a positive correlation between serum iron and insulin resistance index and blood glucose. When the total dietary iron intake greater than 15 mg/d was defined as iron over intake, the risk of suffering from MS was high (OR = 7.12) in those subjects with over intake of total iron. When the animal source iron intake greater than 7.5 mg/d was defined as iron over intake, the risk of suffering from MS was high (OR = 7.73) in those subjects with over intake of animal source iron. Fat and iron intake are influencing factors for MS according to Logistic multiple factor regression analysis. CONCLUSION: Iron overload induced by higher meat-based iron intake might be associated with higher risk of MS.
Assuntos
Sobrecarga de Ferro/complicações , Ferro da Dieta/administração & dosagem , Síndrome Metabólica/etiologia , Síndrome Metabólica/metabolismo , Glicemia/análise , Estudos de Casos e Controles , Dieta , Feminino , Humanos , Resistência à Insulina , Masculino , Carne , Pessoa de Meia-Idade , Fatores de RiscoRESUMO
The preparation of long-wavelength emitting carbon dots (CDs) with good antibacterial function and biosensing ability through element doping method is the hotspot of present researches. This paper reports the rapid synthesis of nitrogen and phosphorus co-doped long wavelength-emitting CDs (N, P-CDs, λem = 530 nm) under low reaction temperature (30 min, 60 °C). This method used glucose, polyethyleneimine and phosphoric acid as raw materials, and each raw material worked multi-functionally during the synthesis process. The impacts of raw materials and reaction parameters upon optical properties of prepared N, P-CDs have been studied, and the synthesis mechanism has been discussed. Meanwhile, N, P-CDs were used as antibacterial material with minimum inhibitory concentrations against Staphylococcus aureus and Escherichia coli at 7.5 µg·mL-1 and 0.5 mg·mL-1 respectively. The prepared CDs were also used to realize fluorescence imaging of S. aureus, and work as fluorescence probe to detect Sudan Red I with limit of detection at 43 nM.
Assuntos
Carbono , Pontos Quânticos , Antibacterianos/farmacologia , Compostos Azo , Staphylococcus aureus , TemperaturaRESUMO
The preparation and performance of doped antibacterial carbon dots (CDs) have been the research hotspot. In this paper, we report the preparation of two blue light-emitting silver-doped CDs, CD-1 and CD-2, through one- and two-step routes, respectively, by using polyethyleneimine, citric acid, and AgNO3 as raw materials. Both CDs exhibited excellent and broad-spectrum activity against gram-positive bacteria, gram-negative bacteria, and fungi. We compared the emission wavelength, surface group, particle size, chargeability, and element content of the two CDs through various characterization methods. CD-2 exhibiting longer emission wavelength, larger particle size, and higher silver content displayed higher antibacterial activity against microorganisms than CD-1. On the other hand, CDs exhibited varying antibacterial properties against different microorganisms because of differences in the cell wall structure of gram-positive bacteria (peptidoglycan), gram-negative bacteria (lipopolysaccharides), and fungi (chitin). Based on scanning electron microscopy observations, circular dichroism spectroscopy and agarose gel electrophoresis, we speculate that CDs exert antibacterial activity mainly through membrane disruption and their effect on intracellular DNA and proteins. At the same time, CDs have multicolor imaging capabilities of Staphylococcus aureus. The antibacterial activity and versatility of bioimaging make them more potential antibacterial agents than traditional agents.