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1.
Soft Matter ; 20(4): 738-753, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38168972

RESUMO

Using a minimal hydrodynamic model, we theoretically and computationally study the Couette flow of active gels in straight and annular two-dimensional channels subject to an externally imposed shear. The gels are isotropic in the absence of externally- or activity-driven shear, but have nematic order that increases with shear rate. Using the finite element method, we determine the possible flow states for a range of activities and shear rates. Linear stability analysis of an unconfined gel in a straight channel shows that an externally imposed shear flow can stabilize an extensile fluid that would be unstable to spontaneous flow in the absence of the shear flow, and destabilize a contractile fluid that would be stable against spontaneous flow in the absence of shear flow. These results are in rough agreement with the stability boundaries between the base shear flow state and the nonlinear flow states that we find numerically for a confined active gel. For extensile fluids, we find three kinds of nonlinear flow states in the range of parameters we study: unidirectional flows, oscillatory flows, and dancing flows. To highlight the activity-driven spontaneous component of the nonlinear flows, we characterize these states by the average volumetric flow rate and the wall stress. For contractile fluids, we only find the linear shear flow and a nonlinear unidirectional flow in the range of parameters that we studied. For large magnitudes of the activity, the unidirectional contractile flow develops a boundary layer. Our analysis of annular channels shows how curvature of the streamlines in the base flow affects the transitions among flow states.

2.
Microb Pathog ; 173(Pt A): 105828, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36243381

RESUMO

The ongoing global pandemic of novel coronavirus pneumonia (COVID-19) caused by the SARS-CoV-2 has a significant impact on global health and economy system. In this context, there have been some landmark advances in vaccine development. Over 100 new coronavirus vaccine candidates have been approved for clinical trials, with ten WHO-approved vaccines including four inactivated virus vaccines, two mRNA vaccines, three recombinant viral vectored vaccines and one protein subunit vaccine on the "Emergency Use Listing". Although the SARS-CoV-2 has an internal proofreading mechanism, there have been a number of mutations emerged in the pandemic affecting its transmissibility, pathogenicity and immunogenicity. Of these, mutations in the spike (S) protein and the resultant mutant variants have posed new challenges for vaccine development and application. In this review article, we present an overview of vaccine development, the prevalence of new coronavirus variants and their impact on protective efficacy of existing vaccines and possible immunization strategies coping with the viral mutation and diversity.


Assuntos
Vacinas contra COVID-19 , COVID-19 , SARS-CoV-2 , Humanos , Anticorpos Antivirais , COVID-19/prevenção & controle , Imunogenicidade da Vacina , Mutação , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/genética , Desenvolvimento de Vacinas , Vacinas de Produtos Inativados
3.
J Environ Manage ; 302(Pt A): 114038, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34739904

RESUMO

Green infrastructures (GIs) have been advocated worldwide to mitigate the negative impact of urbanization on regional hydrological cycle, their functions are closely related to their design features and the local environmental condition. This paper reports a field monitoring study that aimed to investigate how runoff partition in raingardens would affect flow and pollutant retention. A paired field experiment was conducted to compare runoff and pollutant retentions in two raingardens with and without subsurface drainage in a shallow water table area. Concentrations of ammonia nitrogen (NH3-N), nitrate nitrogen (NO3-N) and total phosphorus (TP) were measured at raingarden inflow, overflow and drainage paths. The results from 28 monitored storm events over two years showed that the raingarden without subsurface drainage achieved its retention mainly through ponding and infiltration, its pollutant retention rates (76% for TP, 81% for NO3-N, and 79% for NH3-N) were higher than its runoff retention rate (61%), indicating a first flush effect on pollutants retention in the raingarden during storm events, especially when the raingarden was empty and dry. The raingarden with subsurface drainage facilitated quick discharge of water, the observed runoff reduction through the raingarden was 36%; pollutant removal rates were quite variable: NH3-N was removed by 91% while the NO3-N and TP were increased by 3-47%. These results suggest that facilitating specific processes for targeted pollutants is necessary for achieving substantial pollutant removal in a stormwater retention device. Subsurface drainage pipes resulted in short circulating of runoff and lowered pollutant removal rates in the raingarden. Considering the water table fluctuation during the experimental period, we recommend to build infiltration-based GI devices to better capture first flush in intensively developed urban area, which caused deeper groundwater table. In conclusion, installations of different GI devices in urban landscape need to consider the local environmental conditions and facilitate the design features to meet specific storm runoff and pollutants mitigation requirement.


Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Monitoramento Ambiental , Nitrogênio/análise , Fósforo/análise , Chuva , Movimentos da Água , Poluentes Químicos da Água/análise
4.
Acta Clin Croat ; 61(2): 193-197, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36818924

RESUMO

The aim was to investigate detection of pulmonary alveolar lavage fluid tuberculosis DNA by real-time fluorescent polymerase chain reaction (RT-PCR) combined with clinical application of the sputum smear-negative pulmonary tuberculosis diagnosis with TB interferon-γ release assay (TB-IGRA). From October 2014 to October 2015, 632 outpatients and inpatients treated in our hospital were randomly selected, of which 459 patients as the research group managed with RT-PCR detection combined with TB-IGRA and 173 patients as the control group undergoing electronic bronchoscopy alveolar lavage fluid detection, with detection results statistically evaluated. The positive rate in the research group was 96.51%, i.e. significantly higher than that in the control group (66.47%), yielding a statistically significant difference (χ2=109.68, p=0.00). The true positive rate was 97.7% in the research group and 67.92% in the control group; the true positive rate was significantly higher in the research group patients as compared with the control group, yielding a statistically significant difference (χ2=112.04, p=0.00). The sensitivity and specificity, as well as Youden index were significantly higher in the research group as compared with the control group. In conclusion, TB DNA detection by RT-PCR combined with TB-IGRA is a very good method of diagnosing tuberculosis, and it can be implemented in clinical diagnosis of pulmonary tuberculosis.


Assuntos
Mycobacterium tuberculosis , Tuberculose Pulmonar , Tuberculose , Humanos , Testes de Liberação de Interferon-gama/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Escarro , Tuberculose/diagnóstico , Tuberculose Pulmonar/diagnóstico , Sensibilidade e Especificidade , DNA
5.
J Org Chem ; 85(16): 10973-10979, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32806098

RESUMO

PGL-1 epitope 1 bearing a p-aminoethylphenol group was efficiently synthesized by using linear synthetic routes. A method for efficient synthesis of oligosaccharides containing rhamnose rings was developed. The chemistry is flexible and could be used for the synthesis of other PGLs antigens. A biotinylated PGL-1 antigen 23 was synthesized and could be used as a probe for early detection of leprosy.


Assuntos
Glicolipídeos , Mycobacterium leprae , Anticorpos Antibacterianos , Antígenos de Bactérias , Antígenos de Superfície , Epitopos , Trissacarídeos
6.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 51(6): 873-877, 2020 Nov.
Artigo em Zh | MEDLINE | ID: mdl-33236615

RESUMO

OBJECTIVE: To retrospectively analyze the symptoms and characteristics of nervous system damage in severe/critically severe patients with coronavirus disease 2019 (COVID-19) in Sichuan province, with a view to providing basic references for the prevention and treatment of COVID-19. METHODS: A total of 90 patients with severe/critically severe COVID-19 were included, who were diagnosed and treated in COVID-19 designated hospital of Sichuan province from 11 January 2020 to 20 March 2020. Clinical features, test results, treatment options and clinical outcomes were analyzed retrospectively. RESULTS: Of 90 patients, there were 54 males and 36 females, with an average age of (53.90±16.92) years. In addition to the classic symptoms such as fever and/or respiratory symptoms, 53 patients also had various degrees of neurologic manifestations, including 33 cases of fatigue, 21 muscle soreness, 12 dizziness, 8 headaches, 3 mental disorders, and 1 consciousness disorders and 1 case of neck pain. Compared with the patients without neurologic manifestations, those with neurologic manifestations took a longer time from admission to diagnosis of COVID-19 ( P<0.05), and received more antifungal treatment ( P<0.05). CONCLUSIONS: Neurological symptoms are not uncommon in severe/critically severe patients with COVID-19, and it's relatively difficult in the treatment. It should be paid attention in order to avoid misdiagnosis.


Assuntos
Infecções por Coronavirus/fisiopatologia , Doenças do Sistema Nervoso/virologia , Pneumonia Viral/fisiopatologia , Adulto , Idoso , Betacoronavirus , COVID-19 , China/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Estudos Retrospectivos , SARS-CoV-2
7.
Soft Matter ; 15(31): 6318-6330, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31322161

RESUMO

We study the linear stability of an isotropic active fluid in three different geometries: a film of active fluid on a rigid substrate, a cylindrical thread of fluid, and a spherical fluid droplet. The active fluid is modeled by the hydrodynamic theory of an active nematic liquid crystal in the isotropic phase. In each geometry, we calculate the growth rate of sinusoidal modes of deformation of the interface. There are two distinct branches of growth rates; at long wavelength, one corresponds to the deformation of the interface, and one corresponds to the evolution of the liquid crystalline degrees of freedom. The passive cases of the film and the spherical droplet are always stable. For these geometries, a sufficiently large activity leads to instability. Activity also leads to propagating damped or growing modes. The passive cylindrical thread is unstable for perturbations with wavelength longer than the circumference. A sufficiently large activity can make any wavelength unstable, and again leads to propagating damped or growing modes. Our calculations are carried out for the case of zero Frank elasticity. While Frank elasticity is a stabilizing mechanism as it penalizes distortions of the order parameter tensor, we show that it has a small effect on the instabilities considered here.

8.
Cell Biol Int ; 43(7): 770-780, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31026365

RESUMO

Acute respiratory distress syndrome (ARDS) is an acute, severe, and refractory pulmonary inflammation with high morbidity and mortality. Excessive activation of fibroblast during the fibroproliferative phase plays a pivotal role in the prognosis of ARDS. Our previous study demonstrated that the vasoactive intestinal peptide (VIP) is mediated by lentivirus attenuates lipopolysaccharide (LPS)-induced ARDS in a murine model, and VIP inhibits the release of interleukin-17A (IL-17A) from activation macrophages. However, the effects of VIP on the activation of murine fibroblast and expression of IL-17 receptor (IL-17R) in ARDS remain unclear. Here, a mouse model of ARDS was established by an intratracheal injection of LPS. We found that the gene expression of col3a1 and hydroxyproline contents in the lungs were significantly increased 24 h after LPS injection. IL-17RC rather than IL-17RA was increased in the lungs of mice with ARDS. In vitro, LPS activated NIH3T3 cells, which was suppressed by VIP in a dose-dependent manner. In detail, VIP reduced the hydroxyproline content and col3a1 messenger RNA induced by LPS in NIH3T3 cells, as well as the expression of α-smooth muscle actin. Furthermore, we found that VIP inhibited the expression of IL-17R in the lungs of mice with ARDS and NIH3T3 cells stimulated with LPS, which was partly inhibited by antagonists of protein kinase A and protein kinase C. Taken together, our results demonstrated that VIP inhibited the activation of fibroblast via downregulation of IL-17RC, which may contribute to the protective effects of VIP against ARDS in mice.


Assuntos
Fibroblastos/imunologia , Receptores de Interleucina/imunologia , Síndrome do Desconforto Respiratório/imunologia , Transdução de Sinais/efeitos dos fármacos , Peptídeo Intestinal Vasoativo , Actinas/metabolismo , Animais , Colágeno Tipo III/metabolismo , Modelos Animais de Doenças , Hidroxiprolina/metabolismo , Lipopolissacarídeos/química , Masculino , Camundongos , Células NIH 3T3 , Inibidores de Proteínas Quinases/farmacologia , Receptores de Interleucina-17/imunologia , Peptídeo Intestinal Vasoativo/farmacologia , Peptídeo Intestinal Vasoativo/fisiologia
9.
Lab Invest ; 98(7): 924-934, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29765109

RESUMO

The microvascular profile has been included in the WHO glioma grading criteria. Nevertheless, microvessels in gliomas of the same WHO grade, e.g., WHO IV glioblastoma (GBM), exhibit heterogeneous and polymorphic morphology, whose possible clinical significance remains to be determined. In this study, we employed a fractal geometry-derived parameter, microvascular fractal dimension (mvFD), to quantify microvessel complexity and developed a home-made macro in Image J software to automatically determine mvFD from the microvessel-stained immunohistochemical images of GBM. We found that mvFD effectively quantified the morphological complexity of GBM microvasculature. Furthermore, high mvFD favored the survival of GBM patients as an independent prognostic indicator and predicted a better response to chemotherapy of GBM patients. When investigating the underlying relations between mvFD and tumor growth by deploying Ki67/mvFD as an index for microvasculature-normalized tumor proliferation, we discovered an inverse correlation between mvFD and Ki67/mvFD. Furthermore, mvFD inversely correlated with the expressions of a glycolytic marker, LDHA, which indicated poor prognosis of GBM patients. Conclusively, we developed an automatic approach for mvFD measurement, and demonstrated that mvFD could predict the prognosis and response to chemotherapy of GBM patients.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Encefálicas , Glioma , Interpretação de Imagem Assistida por Computador/métodos , Microvasos/patologia , Neovascularização Patológica/patologia , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Fractais , Glioma/diagnóstico por imagem , Glioma/tratamento farmacológico , Glioma/patologia , Humanos , Imuno-Histoquímica , Microvasos/diagnóstico por imagem , Gradação de Tumores/métodos , Neovascularização Patológica/diagnóstico por imagem , Prognóstico
10.
J Transl Med ; 14: 79, 2016 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-27004414

RESUMO

BACKGROUND: To explore whether plasma fatty acids and SNPs in the fatty acid desaturase (FADS) gene associated with type 2 diabetes (T2D) and coronary artery disease (CAD). METHODS: In this cross-sectional study, we utilized gas chromatography-mass spectrometric analysis and the high-resolution melting method to detect plasma fatty acids and SNPs respectively (rs174537G>T, rs174616C>T, rs174460T>C, and rs174450A>C) in 234 T2D, 200 CAD, 185 T2D&CAD patients, and 253 healthy controls. RESULTS: We found that T2D&CAD patients had the highest plasma arachidonic acid, dihomo-gamma-linolenic acid and delta-6 desaturase, and the lowest stearic acid, linolenic acid, and saturated fatty acids; plasma eicosapentaenoic acid and docosahexaenoic acid elevated in T2D patients, but significantly reduced in CAD patients. Moreover, T2D patients with rs174537 GG genotype were at risk of developing T2D&CAD (odds ratio (OR) 1.763; 95 % CI 1.143-2.718; p = 0.010), with elevated plasma LDL-cholesterol, arachidonic acid, and delta-6 desaturase. CONCLUSIONS: Our results show that SNPs in FADS gene (particularly rs174537) associate with plasma fatty acids and desaturase levels in patients with both T2D and CAD, which maybe increases the risk of CAD in diabetic patients.


Assuntos
Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/genética , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/genética , Ácidos Graxos Dessaturases/genética , Ácidos Graxos/sangue , Polimorfismo de Nucleotídeo Único/genética , Estudos de Casos e Controles , Doença da Artéria Coronariana/complicações , Dessaturase de Ácido Graxo Delta-5 , Diabetes Mellitus Tipo 2/complicações , Feminino , Frequência do Gene/genética , Predisposição Genética para Doença , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Padrões de Referência , Fatores de Risco
12.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(4): 1121-6, 2016 Apr.
Artigo em Zh | MEDLINE | ID: mdl-30052011

RESUMO

Spectral analysis is an important and unique advantageous method for the analysis of matter's structure and composition. Aiming to discuss the change characteristic and evolution mechanism of mineral structure of oil shale, kerogen and sime-coke from oil shale pyrolysis under different temperature, the oil shale sample was obtained from Yaojie located in Gansu province, and the oil shale after pyrolysis experiments and acid washing were investigated and analyzed in detail withpolarizing microscope, Fourier transform spectroscopy (FTIR), X-Ray diffraction (XRD) and scanning electron microscope (SEM). The result shows that the mainly minerals of oil shale include quartz, clay and pyrite; kerogen is randomly distributed as mainly strip-shaped or blocky in inorganic minerals. The metamorphic degree of kerogen is higher, and rich in aliphatic structures and aromatic structures. Experiments of oil shale pyrolysis(temperature: 300~1 000 ℃, heating rate: 10 ℃·min-1) with temperature increasing, the composition of mineral begins to dissolve, kaolinite turning into metakaolinite with dehydration at 300 ℃, clay minerals such as kaolinite and montmorillonite completely turn into metakaolinite at 650 ℃. The silica-alumina spinel and amorphous SiO2, generated from the decomposition of metakaolinite at 1 000 ℃, and the amorphous SiO2, tends to react with iron mineral to form relative low melting point mixture on the semi-coke surfaces, such as FeO­Al2O3­SiO2. kerogen break down with increasing temperature, the infrared spectra intensity of C­H band of aliphatic and aromatic is reduced, while the intensity of C­C band aromatic is increased, and more carbonaceous residue as gully-shaped that remains in the mineral matrix after pyrolysis. These results are important for both the study of structure evolution of kerogen and minerals on the process of oil shale pyrolysis and will benefit for the subsequent processing and utilization of shale oil resource.

13.
J Card Surg ; 30(4): 338-45, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25652312

RESUMO

BACKGROUND: Magnesium is often used to supplement cardioplegic solutions during cardiopulmonary bypass due to its cardioprotective effect during ischemia and reperfusion. The aim of this meta-analysis was to evaluate the effects of magnesium-supplemented cardioplegia versus an inactive (placebo) control cardioplegia on reducing cardiac injury after cardiac arrest surgery, as found by randomized, controlled trials. METHODS: The Medline, Cochrane Library, and Chinese literature databases (CJFD, CBM, CSJD, Wanfang) were comprehensively searched for reports of randomized, controlled trials (RCTs) evaluating magnesium-supplemented cardioplegic solutions. The clinical parameters and outcomes of interest were the incidence of postoperative low cardiac output, auto-rebeating rate, ICU stay length, new onset postoperative atrial fibrillation, peak value of CK-MB (and/or cTnI), incidence of myocardial infarction, and in-hospital mortality. RESULTS: Ten trials, with a total of 1214 patients, were included. The frequency of low cardiac output, inotropic utilization, and myocardial infarction, as well as auto-rebeating rate, length of ICU stay and in-hospital mortality, were similar between the two groups. There was a marginal reduction in the incidence of new-onset postoperative atrial fibrillation in the magnesium-supplemented cardioplegia group. CONCLUSIONS: The advantage of magnesium-supplemented cardioplegia, compared with cardioplegia without magnesium, remains unconvincing based on the current evidence. The decision to add magnesium to the cardioplegic solution to a patient undergoing cardiac arrest surgery should be carefully considered.


Assuntos
Cardiotônicos , Bases de Dados Bibliográficas , Magnésio/administração & dosagem , Magnésio/farmacologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Fibrilação Atrial/epidemiologia , Fibrilação Atrial/prevenção & controle , Baixo Débito Cardíaco/epidemiologia , Baixo Débito Cardíaco/prevenção & controle , Soluções Cardioplégicas , Ponte Cardiopulmonar , Mortalidade Hospitalar , Humanos , Incidência , Tempo de Internação , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/prevenção & controle , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/prevenção & controle
14.
BMC Cardiovasc Disord ; 14: 159, 2014 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-25399059

RESUMO

BACKGROUND: Free fatty acids (FFAs) play importance roles in the development of diabetes and cardiovascular diseases. We measured serum FFA levels from type 2 diabetes mellitus (T2DM) and acute myocardial infarction (AMI) patients and assay the correlation between serum FFA levels and related factors. The present study was undertaken to investigate a possible relation between the changes in serum free fatty acid concentration with acute myocardial infarction and type 2 diabetes mellitus. METHODS: The study population consisted of 540 healthy individuals and 103 patients with T2DM, 59 patients with AMI and 21 volunteers. Serum FFAs were measured with high pressure liquid chromatography. Blood urea nitrogen and uric acid were measured in clinical laboratory, as were glycemic, lipid and blood routine parameters. We selected 242 individuals with age over 60 years, 143 healthy individuals and 52 patients with T2DM, 47 patients with AMI were incorporated into three groups as control group, T2DM group and AMI group. Associations were analyzed with stepwise regression analysis with adjusted for age, sex, body mass index. RESULTS: Serum FFA levels were significantly higher in the age over 60 years individuals compared to 20 ~ 50 years (logFFA µmmol/L:2.60 ± 0.16 vs. 2.73 ± 0.18, P < .001) in the healthy group. We found lower FFA levels in the AMI compared to the T2DM and control group (2.64 ± 0.22 vs. 2.72 ± 0.13&2.72 ± 0.16, respectively, P < .05&P < 0.01) in the age over 60, fasting blood glucose level higher in the AMI and T2DM (5.78 ± 1.32&7.75 ± 2.93 mmol/L vs. 4.90 ± 0.47 mmol/L, P < .01&P < .001) compared with the normal group, HDL level (1.01 ± 0.22&0.98 ± 0.18 mmol/L vs.1.30 ± 0.22 mmol/L, P < .001&P < .001). With stepwise regression analysis, the serum FFA levels was positively associated with the HDL in the control group (YlogFFA = 2.32 + 0.33XHDL, R = 0.26, P < .01) and T2MD (YlogFFA = 2.46 + 0.27XHDL, R = 0.36, P < .05), AST in AMI (YlogFFA =2.24 + 0. 015XAST, R = 0.49, P < .01). CONCLUSIONS: Compared to control group, serum FFA levels were decreased only in AMI group, while HDL level was increased in both AMI and T2DM group. The serum FFA levels were positive association with the HDL level in both T2DM and control group, FFA levels were positive association with AST in AMI.


Assuntos
Diabetes Mellitus Tipo 2/sangue , Ácidos Graxos não Esterificados/sangue , Infarto do Miocárdio/sangue , Adulto , Biomarcadores/sangue , Nitrogênio da Ureia Sanguínea , Estudos de Casos e Controles , China/epidemiologia , HDL-Colesterol/sangue , Cromatografia Líquida de Alta Pressão , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/epidemiologia , Fatores de Risco , Ácido Úrico/sangue , Adulto Jovem
15.
J Colloid Interface Sci ; 670: 576-584, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38776692

RESUMO

The misfolding and aggregation of α-synuclein monomers usually cause the occurrence and development of Parkinson's disease (PD). It is important to develop effective methods for detection of α-synuclein aggregates. Carbon dots (CDs) could be the potential fluorescence probe for this purpose owing to their appreciated optical properties. However, undefined structure of CDs and complicated three-dimensional structure of protein severely hindered the design of fluorescence probe towards protein aggregates. Herein, a red emissive fluorescent amphiphilic CD, named as CL-9, was designed with a high sensitivity to α-synuclein fibrils by a one-step heating process, using the ternary carbon source, including Congo red, l-tryptophan and urea. The CL-9 exhibited turn-on red emissive fluorescence towards α-synuclein fibril, but remained no change towards its monomer. Compared with the original Congo red dye, CL-9 exhibited stronger turn-on red fluorescence towards α-synuclein fibrils with better anti-photobleaching resistance, biocompatibility and signal-to-noise ratio. The CL-9 was successful as a fluorescent probe to image α-synuclein fibrils in NL-5901 C. elegans. The present study provided a feasible approach using the multiple carbon sources to construct the CDs based fluorescence probe targeting amyloid proteins.


Assuntos
Carbono , Corantes Fluorescentes , alfa-Sinucleína , alfa-Sinucleína/química , alfa-Sinucleína/análise , Carbono/química , Corantes Fluorescentes/química , Animais , Pontos Quânticos/química , Humanos , Caenorhabditis elegans/metabolismo , Vermelho Congo/química , Amiloide/química , Tamanho da Partícula , Imagem Óptica
16.
Langmuir ; 29(9): 3106-15, 2013 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-23339577

RESUMO

We report the electrical transport characteristics of a series of molecular wires, fc-C≡C-C6H4-SAc (fc = ferrocenyl; Ac = acetyl) and AcS-C6H4-C≡C-(fc)n-C≡C-C6H4-SAc (n = 2, 3), consisting of multiple redox-active ferrocenyl centers. The self-assembled monolayers of these molecular wires on Au surfaces were comprehensively characterized by electrochemistry and conductive atomic force microscopy techniques. Characterization of the wires revealed that electron transport is made extremely efficient by the organometallic redox states. There is a strong electronic coupling between ferrocenyl moieties, and superior electron-transport ability exists through these semirigid molecular wires. Standard rate constants for the electron transfer between the electrode and the ferrocenyl moieties were measured for the monolayers by a potential-step chronoamperometry technique. The electron conduction through the molecular wires was estimated using the monolayers as a bridge from the Au(111) metal surface to the gold tip of a conductive atomic force microscope (CAFM). Using the CAFM, Coulomb blockade behavior arising from the capacitive charging of the multinuclear redox-active molecules was observed at room temperature. The conductance switching was mediated by the presence of various ferrocenyl redox states and each current step corresponded to a specific redox state.

17.
Int J Biol Macromol ; 231: 123319, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36682666

RESUMO

The aggregation of amyloid proteins is highly related to the occurrence and development of neurodegenerative and metabolic diseases. The detection of amyloid fibrils or monitoring fibrillation process would be necessary to understand the fundamental knowledge about the diseases and further facilitate the research for the drug discovery and disease treatment. In this study, three proto-berberine alkaloids, i.e. berberine, palmatine and coptisine, were examined as three distinctive fluorescent probes to detect amyloid fibrils. These three alkaloids were found to be sensitive to the microenvironment, i.e. viscosity and polarity, with varied fluorescence intensity. They could sensitively probe insulin and lysozyme fibrils with turn-on fluorescence, but did not respond to protein monomers, merited with advantages of larger Stokes shift, greenish-yellow fluorescence and no interference with the fibrillation process. Hydrophobic, electrostatic and hydrogen bond interactions were explored to exist between alkaloids and the fibrils. Moreover, these alkaloids succeeded in monitoring the aggregation process of amyloid proteins in vitro and imaging the fibrils in living cells. The present study demonstrates that the three alkaloids could be the potential candidate fluorescent probes for amyloid fibrils.


Assuntos
Alcaloides , Alcaloides de Berberina , Amiloide , Corantes Fluorescentes/química , Fluorescência , Proteínas Amiloidogênicas
18.
Microbiol Spectr ; : e0480522, 2023 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-36861984

RESUMO

Pathogenic fungi are the main cause of yield loss and postharvest loss of crops. In recent years, some antifungal microorganisms have been exploited and applied to prevent and control pathogenic fungi. In this study, an antagonistic bacteria KRS027 isolated from the soil rhizosphere of a healthy cotton plant from an infected field was identified as Burkholderia gladioli by morphological identification, multilocus sequence analysis, and typing (MLSA-MLST) and physiobiochemical examinations. KRS027 showed broad spectrum antifungal activity against various phytopathogenic fungi by secreting soluble and volatile compounds. KRS027 also has the characteristics of plant growth promotion (PGP) including nitrogen fixation, phosphate, and potassium solubilization, production of siderophores, and various enzymes. KRS027 is not only proven safe by inoculation of tobacco leaves and hemolysis test but also could effectively protect tobacco and table grapes against gray mold disease caused by Botrytis cinerea. Furthermore, KRS027 can trigger plant immunity by inducing systemic resistance (ISR) activated by salicylic acid- (SA), jasmonic acid- (JA), and ethylene (ET)-dependent signaling pathways. The extracellular metabolites and volatile organic compounds (VOCs) of KRS027 affected the colony extension and hyphal development by downregulation of melanin biosynthesis and upregulation of vesicle transport, G protein subunit 1, mitochondrial oxidative phosphorylation, disturbance of autophagy process, and degrading the cell wall of B. cinerea. These results demonstrated that B. gladioli KRS027 would likely become a promising biocontrol and biofertilizer agent against fungal diseases, including B. cinerea, and would promote plant growth. IMPORTANCE Searching the economical, eco-friendly and efficient biological control measures is the key to protecting crops from pathogenic fungi. The species of Burkholderia genus are widespread in the natural environment, of which nonpathogenic members have been reported to have great potential for biological control agents and biofertilizers for agricultural application. Burkholderia gladioli strains, however, need more study and application in the control of pathogenic fungi, plant growth promotion, and induced systemic resistance (ISR). In this study, we found that a B. gladioli strain KRS027 has broad spectrum antifungal activity, especially in suppressing the incidence of gray mold disease caused by Botrytis cinerea, and can stimulate plant immunity response via ISR activated by salicylic acid- (SA), jasmonic acid- (JA), and ethylene (ET)-dependent signaling pathways. These results indicate that B. gladioli KRS027 may be a promising biocontrol and biofertilizer microorganism resource in agricultural applications.

19.
Ir J Med Sci ; 192(6): 2681-2687, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37414978

RESUMO

PURPOSE: To investigate the value of serum free prostate-specific antigen density (fPSAD) in the diagnosis of prostate cancer (PCa). METHODS: The data of 558 patients who underwent transrectal ultrasound-guided prostate biopsy were retrospectively analyzed. According to the pathological results, the patients were divided into a PCa group and a benign prostatic hyperplasia (BPH) group. Receiver operating characteristic curves were plotted, based on which the sensitivity, specificity, Youden index, concordance, and kappa values of free prostate-specific antigen (fPSA), the free-to-total f/tPSA, prostate-specific antigen density (PSAD), the free-to-total (f/t)/PSAD ratio, and fPSAD were compared. The patients were divided into three groups by PSA levels (PSA < 4 ng/mL, PSA = 4-10 ng/mL, and PSA > 10 ng/mL), into three groups by age (age < 60 year, age = 60-80y, and age > 80 years), and into two groups by prostate volume (PV) (PV ≤ 80 mL and PV > 80 mL) to compare the sensitivity, specificity, and concordance of indicators. RESULTS: tPSA, PSAD, (f/t)/PSAD, and fPSAD had high accuracy in predicting PCa with AUC values of 0.820, 0.900, 0.846, and 0.867. fPSAD showed lower diagnostic sensitivity but significantly higher specificity and concordance for PCa than tPSA, f/tPSA, (f/t)/PSAD, or PSAD. Thus, fPSAD had the highest accuracy in the diagnosis of PCa. In the groups with different PSA, age, and PV stratification, the concordance of fPSAD was significantly higher (88.61%, 90.74%, and 90.38%) than that of other indicators. CONCLUSION: With the optimal cutoff value of 0.062, fPSAD has a higher diagnostic value for PCa than tPSA, f/tPSA, (f/t)/PSAD, and PSAD, and can well predict the risk of PCa, significantly improve the clinical diagnostic rate of PCa, and reduce unnecessary biopsy.


Assuntos
Hiperplasia Prostática , Neoplasias da Próstata , Masculino , Humanos , Pessoa de Meia-Idade , Antígeno Prostático Específico , Estudos Retrospectivos , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/patologia , Próstata/diagnóstico por imagem , Próstata/patologia , Hiperplasia Prostática/diagnóstico , Curva ROC , Sensibilidade e Especificidade
20.
Artigo em Inglês | MEDLINE | ID: mdl-36691597

RESUMO

Background: Diet acts on the human body through digestion in the stomach and absorption in the intestines. Thus, the emptying of the stomach should be the focus of the research mechanism of the combined medicine and food treatment of diabetes. The emptying function of the stomach and the secretion of related hormones may be the key points of traditional Chinese medicine. In the clinic, Yunvjian is a famous traditional Chinese formula for preventing and curing diabetes. However, the pharmacological action and mechanism of Yunvjian are also need to be probe. Objective: To assess the effect of Yunvjian on glucose, insulin level and gastric emptying function and related hormones on high-fat diet combined with STZ-induced diabetic rats. Methods: High-fat diet combined with STZ was used to construct type 2 diabetes mellitus (T2DM) rats model and received a 4-week Yunvjian administration. The animals were divided into 6 groups, respectively, as the Control group, the DM group, the DM + Acarbose group, the DM + YNH group, and the DM + YNL group. Radionuclide single-photon emission computed tomography (SPECT) technology was used to observe the gastric emptying rate and half-empty time; blood was took to test fasting insulin, and then the insulin resistance index (HOMA-IR) was calculated; HE staining was performed to detect islets and gastric antrum, immunohistochemical staining was performed to detect the number and morphology of pancreatic ß cells and gastric antrum Cajal cells, and the average optical density was calculated; the expression of ghrelin hormone in gastric antrum and serum was detected by ELISA and immunofluorescence; the expression of GHRS mRNA in gastric antrum was detected by RT-PCR method. Results: Yunvjian could significantly improve the glucose level and insulin function of rats. Compared with the DM group, Yunvjian was beneficial to low fasting blood glucose (FBG) (P < 0.01), increased glucose tolerance, and improved islet function at the same time (P < 0.05). At the same time, compared with the DM group (25.02 ± 0.05, 44 ± 12.33), the emptying rate of the DM + YNH group was significantly faster (64.98 ± 0.12), and the half row time was shortened (26 ± 8.29, P < 0.05). The gastric ghrelin levels in each group of Yunvjian increased with different degrees compared with the DM group (616.2 ± 26.23), especially in the DM + YNH group (863.51 ± 23.76, P < 0.01). Correspondingly, the expression of gastric GHSR mRNA in the DM + YNH and DM + YNL groups increased significantly compared with the DM group (P < 0.01). Conclusions: Yunvjian can effectively control glucose and improve islet function, which may be closely related to its influence on gastric emptying function and related hormone secretion regulation.

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