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1.
J Neurochem ; 2021 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-33694231

RESUMO

Extracellular plaque deposits of ß-amyloid peptide (Aß) are one of the main pathological features of Alzheimer's disease (AD). The aggregation of Aß42 species, especially Aß42 oligomers, is still an active research field in AD pathogenesis. Secretory clusterin protein (sCLU), an extracellular chaperone, plays an important role in AD pathogenesis. Although sCLU interacts directly with Aß42 in vitro and in vivo, the mechanism is not clear. In this paper, His-tagged sCLU (sCLU-His) was cloned, expressed and purified, and we applied florescence resonance energy transfer-fluorescence correlation spectroscopy (FRET-FCS) to investigate the direct interaction of sCLU-His and Aß42 at the single-molecule fluorescence level in vitro. Here, we chose four different fluorescently labeled Aß42 oligomers to form two different groups of aggregation models, easy or difficult to aggregate. The results showed that sCLU-His could form complexes with both aggregation models, and sCLU-His inhibited the aggregation of Aß42/RB  ~ Aß42/Atto647 (easy to aggregate model). The complexes were produced as the Aß42/Label adhered to the sCLU-His, which is similar to a "strawberry model," as strawberry seeds are dotted on the outer surface of strawberries. This work provided additional insight into the interaction mechanism of sCLU and Aß42 .

2.
J Phys Chem Lett ; 12(11): 2727-2735, 2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33705142

RESUMO

pH sensing plays a key role in the life sciences as well as the environmental, industrial, and agricultural fields. Carbon nanodots (C-dots) with small size, low toxicity, and excellent stability hold great potential in pH sensing as nanoprobes due to their intrinsic pH-sensitive photoluminescence (PL). Nonetheless, the undesirable sensitivity and response range of C-dot PL toward pH cannot meet the requirements of practical applications, and the unclear pH-sensitive PL mechanism makes it difficult to control their pH sensitivity. Herein, the quantitative correlation of pH-sensitive PL with specific surface structures of C-dots is uncovered for the first time, to our best knowledge. The association of carboxylate and H+ increases the ratio of nonradiation to radiation decay of C-dots through excited-state proton transfer, resulting in the decrease of PL intensity. Meanwhile, the dissociation of α-H in ß-dicarbonyl forming enolate increases the extent of delocalization of the C-dots conjugated system, which induces the PL broadening to the red region and a decreasing intensity. Based on the understanding of the pH-sensitive PL mechanism, the pH-sensitive PL of C-dots can be switched by quantitative modulation of carboxyl and ß-dicarbonyl groups to achieve a desirable pH response range with high sensitivity. This work contributes to a better understanding of the pH-sensitive PL of C-dots and therefore presents an effective strategy for controllably tuning their pH sensitivity, facilitating the rational design of C-dot-based pH sensors.

3.
Arch Microbiol ; 2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33710378

RESUMO

A novel Gram-stain positive, oval-shaped, and non-flagellated bacterium, designated YIM S02566T, was isolated from alpine soil in Shadui Towns, Ganzi County, Ganzi Tibetan Autonomous Prefecture, Sichuan Province, PR China. Growth occurred at 23-35 °C (optimum, 30 °C) in the presence of 0.5-4% (w/v) NaCl (optimum, 1%) and at pH 7.0-8.0 (optimum, pH 7.0). The phylogenetic analysis based on 16S rRNA gene sequence revealed that strain YIM S02566T was most closely related to the genus Aestuariimicrobium, with Aestuariimicrobium kwangyangense R27T and Aestuariimicrobium soli D6T as its closest relative (sequence similarities were 96.3% and 95.4%, respectively). YIM S02566T contained LL-diaminopimelic acid in the cell wall. MK-9(H4) was the predominant menaquinone. The major fatty acid patterns were anteiso-C15:0 (60.0%). The major polar lipid was DPG. The genome size of strain YIM S02566T was 3.1 Mb, comprising 3078 predicted genes with a DNA G + C content of 69.0 mol%. Based on these genotypic, chemotaxonomic and phenotypic evidences, strain YIM S02566T was identified as a novel species in the genus Aestuariimicrobium, for which the name Aestuariimicrobium ganziense sp. nov. is proposed. The type strain is YIM S02566T (= CGMCC 1.18751 T = KCTC 49,477 T).

4.
Hum Cell ; 34(2): 419-435, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33586121

RESUMO

Since December 2019, the novel coronavirus SARS-CoV-2 pandemic (COVID-19) outbroke in Wuhan and spread in China. Here we aimed to investigate the clinical and radiological characteristics of COVID-19 cases. We collected and analyzed the clinical data of 172 hospitalized cases of COVID-19 who were diagnosed via qRT-PCR of nasopharyngeal swabs during January 2020 and February 2020. The chest images were reviewed by radiologists and respirologists. The older patients with COVID-19 in Henan Province had more severe disease and worse prognosis. The male sex, smoking history and Wuhan exposure of patients are not related to the severity or prognosis of COVID-19. Family gatherings were showed among 26.7% of patients. A greater proportion of patients in the severe group suffer from combined chronic diseases. CT results showed that most patients had bilateral lung lesions and multiple lung lobes. The lungs of severe patients are more damaged. Both the infection range and inflammatory factor levels are related to the poor prognosis. Antiviral drugs, immunoglobulin and traditional Chinese medicine are mainly used for the treatment of COVID-19 patients. The discharge rate of COVID-19 patients was 93.0%, and the mortality rate was 2.3%. Case type, lymphocyte ratio grade, and respiratory failure at admission are risk factors for poor prognosis, except for the number of infiltrating lung lobes. The results showed that severe disease process, lymphopenia and respiratory failure are risk factors for the COVID-19.


Assuntos
/diagnóstico , Adulto , Idoso , Antivirais/uso terapêutico , /mortalidade , China/epidemiologia , Comorbidade , Diagnóstico Diferencial , Feminino , Glicosídeos , Humanos , Imunoglobulinas/uso terapêutico , Pulmão/diagnóstico por imagem , Contagem de Linfócitos , Linfopenia , Masculino , Medicina Tradicional Chinesa , Pessoa de Meia-Idade , Pregnanos , Prognóstico , Fatores de Risco , Índice de Gravidade de Doença , Fatores Sexuais , Fumar/efeitos adversos , Tomografia Computadorizada por Raios X
5.
J Investig Med ; 69(3): 704-709, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33361401

RESUMO

China has experienced an outbreak of COVID-19 since December 2019. This study investigated the differences between the imported and local cases of COVID-19 in Nanyang, China. In this study, a total of 129 COVID-19 confirmed cases with a clear epidemiological history admitted to hospitals in Nanyang from January 24 to February 26, 2020 were enrolled. Patients who had a travel history to or a residence history in Wuhan or in the surrounding areas in Hubei Province within 14 days before the illness onset were assigned to the imported group (n=70), and the others were assigned to the local group (n=59). The differences in epidemiological characteristics, clinical features, laboratory and imaging results, and prognosis were compared between the 2 groups. The early diagnosed cases were mainly imported cases, and the later diagnosed ones were mainly local cases. The most common first symptom was fever; moderate fever was commonly seen in imported cases whereas low fever was commonly seen in local cases. Lymphocyte counts in the imported group were lower than those in the local group. The imported group showed more advanced and severe abnormalities in the CT scan whereas the local group showed milder pulmonary abnormalities. The proportion of severe and critically severe patients in the imported group was higher than that in the local group. In conclusion, the imported cases have more severe or critically severe patients with a higher mortality rate than the local cases.


Assuntos
/epidemiologia , Pandemias , Adulto , /transmissão , China/epidemiologia , Estudos de Coortes , Feminino , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Índice de Gravidade de Doença , Viagem
6.
Biochem Pharmacol ; 183: 114340, 2020 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-33189675

RESUMO

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a type of chronic bladder inflammation characterized by increased voiding frequency, urgency and pelvic pain. The sensitization of bladder afferents is widely regarded as one of the pathophysiological changes in the development of IC/BPS. There is evidence that adenosine A2a receptors are involved in regulating the sensitization of sensory afferents. However, the effect of adenosine A2a receptors on cystitis remains unknown. In the present study, a rat model of chronic cystitis was established by intraperitoneal injection with cyclophosphamide (CYP). Cystometry and behavioral tests were performed to investigate bladder micturition function and nociceptive pain. The rats with chronic cystitis showed symptoms of bladder overactivity, characterized by an increase in bladder voiding frequency and voiding pressure. CYP treatment significantly increased the expression of the A2a receptor in bladder afferent fibers and dorsal root ganglion (DRG) neurons. The A2a receptor antagonist ZM241385 prevented bladder overactivity and hyperalgesia elicited by CYP-induced cystitis. In addition, the A2a receptor and TRPV1 were coexpressed on DRG neurons. The TRPV1 antagonist capsazepine blocked bladder overactivity induced by the A2a receptor agonist CGS21680. In contrast, ZM241385 significantly inhibited the capsaicin-induced increase in intracellular calcium concentration in DRG neurons. These results suggest that suppression of adenosine A2a receptors in bladder afferents alleviates bladder overactivity and hyperalgesia elicited by CYP-induced cystitis in rats by inhibiting TRPV1, indicating that the adenosine A2a receptor in bladder afferents is a potential therapeutic target for the treatment of IC/BPS.

7.
Phytochemistry ; 181: 112567, 2020 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-33197742

RESUMO

Seven previously undescribed diterpenoid alkaloids, including five C20-diterpenoid alkaloids, barpuberudine, barpubesines A-D, and two C18-diterpenoid alkaloids, barpubenines A-B, along with 11 known diterpenoid alkaloids were isolated from the whole plant of Aconitum barbatum var. puberulum Ledeb. (Ranunculaceae). Barpuberudine is an unprecedented carbon skeleton of C20-diterpenoid alkaloid, while barpubenines A-B are the first example of rearranged types in C18-diterpenoid alkaloids. Their structures were elucidated based on a comprehensive spectroscopic data analysis. The probable pathway of biogenesis of barpuberudine and barpubenines A-B were discussed. Additionally, the antiarrhythmic, cytotoxic and antimicrobial activities of isolates were also evaluated.

8.
J Chem Phys ; 153(17): 170903, 2020 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-33167636

RESUMO

It is well documented that conventional methods such as dynamic light scattering have encountered difficulties in characterizing charged macromolecules and, therefore, it is desirable that new methods and techniques are introduced. With the ultra-high sensitivity, single molecule fluorescence spectroscopy has successfully lowered the detection limit considerably and enabled measurement under extreme dilution conditions-around the concentration of 10-9M-at which the effect of inter-chain electrostatic repulsion is suppressed. Furthermore, the excellent spatial and temporal resolution as well as the capacity of molecular recognition of these methods help in obtaining rich information of charged macromolecules. This paper summarizes the applications of single molecule fluorescence spectroscopy, especially fluorescence correlation spectroscopy and photon counting histogram, in the studies on charged macromolecules in aqueous solutions and plenty of new information has been revealed on the molecular conformation, counterion distribution, and a few important governing factors. The powerfulness and effectiveness of single molecule fluorescence spectroscopy make it promising in the investigations of charged macromolecules.

9.
Signal Transduct Target Ther ; 5(1): 240, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33060566

RESUMO

The COVID-19 pandemic has emerged as a global health emergency due to its association with severe pneumonia and relative high mortality. However, the molecular characteristics and pathological features underlying COVID-19 pneumonia remain largely unknown. To characterize molecular mechanisms underlying COVID-19 pathogenesis in the lung tissue using a proteomic approach, fresh lung tissues were obtained from newly deceased patients with COVID-19 pneumonia. After virus inactivation, a quantitative proteomic approach combined with bioinformatics analysis was used to detect proteomic changes in the SARS-CoV-2-infected lung tissues. We identified significant differentially expressed proteins involved in a variety of fundamental biological processes including cellular metabolism, blood coagulation, immune response, angiogenesis, and cell microenvironment regulation. Several inflammatory factors were upregulated, which was possibly caused by the activation of NF-κB signaling. Extensive dysregulation of the lung proteome in response to SARS-CoV-2 infection was discovered. Our results systematically outlined the molecular pathological features in terms of the lung response to SARS-CoV-2 infection, and provided the scientific basis for the therapeutic target that is urgently needed to control the COVID-19 pandemic.


Assuntos
Betacoronavirus/patogenicidade , Infecções por Coronavirus/genética , Lesão Pulmonar/genética , Pneumonia Viral/genética , Proteoma/genética , Proteômica/métodos , Síndrome Respiratória Aguda Grave/genética , Idoso , Autopsia , Infecções por Coronavirus/metabolismo , Infecções por Coronavirus/patologia , Infecções por Coronavirus/virologia , Citocinas/genética , Citocinas/metabolismo , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Ontologia Genética , Humanos , Pulmão/metabolismo , Pulmão/patologia , Pulmão/virologia , Lesão Pulmonar/metabolismo , Lesão Pulmonar/patologia , Lesão Pulmonar/virologia , Masculino , Redes e Vias Metabólicas , Anotação de Sequência Molecular , NF-kappa B/genética , NF-kappa B/metabolismo , Pandemias , Pneumonia Viral/metabolismo , Pneumonia Viral/patologia , Pneumonia Viral/virologia , Proteoma/metabolismo , Síndrome Respiratória Aguda Grave/metabolismo , Síndrome Respiratória Aguda Grave/patologia , Síndrome Respiratória Aguda Grave/virologia , Índice de Gravidade de Doença , Transdução de Sinais
10.
Materials (Basel) ; 13(20)2020 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-33066311

RESUMO

We studied the microstructures and isothermal oxidation of the Nb-silicide-based alloys Nb-11.5Ti-18Si-5Mo-2W-4.9Sn-4.6Ge-4.5Cr-4.7Al-1Hf (JZ4) and Nb-21Ti-18Si-6.7Mo-1.2W-4.4Sn-4.2Ge-4Cr-3.7Al-0.8Hf (JZ5), calculated their average creep rate for the creep goal conditions of T = 1200 °C and σ = 170 MPa, and compared properties of the two alloys with those of other refractory metal (RM) complex concentrated alloys (RCCAs). Both alloys had a density less than 7.3 g/cm3 and lower than the density of multiphase bcc solid solution + M5Si3 silicide RCCAs. There was macrosegregation of Si in both alloys, which had the same phases in their as-cast microstructures, namely ßNb5Si3, αNb5Si3, A15-Nb3X (X = Al, Ge, Si, Sn), TM5Sn2X (X = Al, Ge, Si), C14-Cr2Nb, but no solid solution. After heat treatment at 1500 °C for 100 h, a low volume fraction of a W-rich (Nb, W)ss solid solution was observed in both alloys together with ßNb5Si3, αNb5Si3 and A15-Nb3X but not the TM5Sn2X, whereas the Laves phase was observed only in JZ4. At 800 °C, both alloys did not pest, and there was no spallation of their scales at 1200 °C. At both temperatures, both alloys followed parabolic oxidation kinetics and their weight changes were lower than those of Ti-rich Nb-silicide-based alloys. The oxidation of both alloys was superior to that of other RCCAs studied to date. For each alloy the Si macrosegregation, volume fraction of solid solution, chemical composition of solid solution and Nb5Si3, and weight changes in isothermal oxidation at 800 and 1200 °C that were calculated using the alloy design methodology NICE agreed well with the experimental results.

11.
Aging (Albany NY) ; 12(19): 18878-18888, 2020 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-33031060

RESUMO

In this retrospective study we assessed the efficacy and safety of tocilizumab in patients with critical or severe coronavirus disease 2019 (COVID-19). We enrolled 181 patients admitted to Huoshenshan Hospital (Wuhan, China) with confirmed COVID-19 between January 2020 and February 2020. Ninety-two patients were treated with tocilizumab, and 89 patients were treated conventionally. We analyzed the clinical manifestations, changes in CT scan images, and laboratory tests before and after tocilizumab treatment, and compared these results with the conventionally treated group. A significant reduction in the level of C-reactive protein was observed 1 week after tocilizumab administration. In some cases this meant the end of the IL-6-related cytokine storm. In addition, tocilizumab relieved fever, cough, and shortness of breath with no reported adverse drug reactions. These findings suggest tocilizumab improves clinical outcomes and is effective for treatment of patients with critical or severe COVID-19. However, future clinical trials are needed to better understand the impact of tocilizumab interference with IL-6 and provide a therapeutic strategy for treatment of COVID-19.

12.
Zhongguo Zhong Yao Za Zhi ; 45(16): 3790-3796, 2020 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-32893572

RESUMO

Forskolin is a complex labdane plant diterpenoid, which has been used in the treatment of a variety of diseases based on its activity as an activator of adenosine monophosphate(cAMP) cyclase. Natural forskolin exists only in the cork layer of the root of Coleus forskohlii. Due to the complexity of the extraction and chemical synthesis processes, the yield and purity of forskolin cannot meet commercial requirements. In recent years, with the rapid development of synthetic biology and the analysis and interpretation of many diterpene biosynthetic pathways, a new approach has been provided for the green production of forskolin. In this paper, the structure, activity, biosynthetic pathway and the heterologous biosynthesis of forskolin were reviewed. The problems and solutions in the heterologous biosynthesis of forskolin were also discussed and summarized, which will provide references for the construction of high-yielding forskolin engineering strains.


Assuntos
Vias Biossintéticas , Colforsina
13.
Chin Med J (Engl) ; 133(20): 2429-2436, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-32889908

RESUMO

BACKGROUND: Endothelial cells play a key role in the cytokine storm caused by influenza A virus. MicroRNA-155 (miR-155) is an important regulator in inflammation. Its role in the inflammatory response to influenza A infection, however, has yet to be elucidated. In this study, we explored the role as well as the underlying mechanism of miR-155 in the cytokine production in influenza A-infected endothelial cells. METHODS: Human pulmonary microvascular endothelial cells (HPMECs) were infected with the influenza A virus strain H1N1. The efficiency of H1N1 infection was confirmed by immunofluorescence. The expression levels of proinflammatory cytokines and miR-155 were determined using real-time polymerase chain reaction. A dual-luciferase reporter assay characterized the interaction between miR-155 and sphingosine-1-phosphate receptor 1 (S1PR1). Changes in the target protein levels were determined using Western blot analysis. RESULTS: MiR-155 was elevated in response to the H1N1 infection in HPMECs (24 h post-infection vs. 0 h post-infection, 3.875 ±â€Š0.062 vs. 1.043 ±â€Š0.013, P = 0.001). Over-expression of miR-155 enhanced inflammatory cytokine production (miR-155 mimic vs. negative control, all P < 0.05 in regard of cytokine levels) and activation of nuclear factor kappa B in infected HPMECs (miR-155 mimic vs. negative control, P = 0.004), and down-regulation of miR-155 had the opposite effect. In addition, S1PR1 was a direct target of miR-155 in the HPMECs. Inhibition of miR-155 enhanced the expression of the S1PR1 protein. Down-regulation of S1PR1 decreased the inhibitory effect of the miR-155 blockade on H1N1-induced cytokine production and nuclear factor kappa B activation in HPMECs. CONCLUSION: MiR-155 maybe modulate influenza A-induced inflammatory response by targeting S1PR1.

14.
World J Gastroenterol ; 26(25): 3562-3576, 2020 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-32742126

RESUMO

The gastrointestinal tract is the key interface between the ingesta and the human body. There is wide recognition that the gastrointestinal response to nutrients or bioactive compounds, particularly the secretion of numerous hormones, is critical to the regulation of appetite, body weight and blood glucose. This concept has led to an increasing focus on "gut-based" strategies for the management of metabolic disorders, including type 2 diabetes and obesity. Understanding the underlying mechanisms and downstream effects of nutrient-gut interactions is fundamental to effective translation of this knowledge to clinical practice. To this end, an array of research tools and platforms have been developed to better understand the mechanisms of gut hormone secretion from enteroendocrine cells. This review discusses the evolution of in vitro and in vivo models and the integration of innovative techniques that will ultimately enable the development of novel therapies for metabolic diseases.

15.
Materials (Basel) ; 13(17)2020 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-32842708

RESUMO

The microstructures and properties of the alloys JZ3 (Nb-12.4Ti-17.7Si-6Ta-2.7W-3.7Sn-4.8Ge-1Hf-4.7Al-5.2Cr) and JZ3+(Nb-12.4Ti-19.7Si-5.7Ta-2.3W-5.7Sn-4.9Ge-0.8Hf-4.6Al-5.2Cr) were studied. The densities of both alloys were lower than the densities of Ni-based superalloys and many of the refractory metal complex concentrated alloys (RCCAs) studied to date. Both alloys had Si macrosegregation and the same phases in their as cast and heat treated microstructures, namely ßNb5Si3, αNb5Si3, A15-Nb3X (X = Al, Ge, Si, Sn), C14-Cr2Nb and solid solution. W-rich solid solutions were stable in both alloys. At 800 °C only the alloy JZ3 did not show pest oxidation, and at 1200 °C a thin and well adhering scale formed only on JZ3+. The alloy JZ3+ followed parabolic oxidation with rate constant one order of magnitude higher than the single crystal Ni-superalloy CMSX-4 for the first 14 h of oxidation. The oxidation of both alloys was superior to that of RCCAs. Both alloys were predicted to have better creep at the creep goal condition compared with the superalloy CMSX-4. Calculated Si macrosegregation, solid solution volume fractions, chemical compositions of solid solution and Nb5Si3, weight changes in isothermal oxidation at 800 and 1200 °C using the alloy design methodology NICE agreed well with the experimental results.

16.
J Int Med Res ; 48(7): 300060520920057, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32723127

RESUMO

OBJECTIVE: This study aimed to systematically analyze the effectiveness and safety of the local application of vancomycin powder to prevent surgical site infection (SSI) after spinal surgeries and provide guidance for clinical practice. METHODS: Two researchers independently searched PubMed, Web of Science, Elsevier, and China National Knowledge Infrastructure using the MeSH terms "spinal surgery," "vancomycin," "local," "topical," "prophylactic," "surgical site infection," and "SSI" to identify studies published between January 2010 and January 2020 on the local application of vancomycin powder for preventing SSI after spinal surgeries. The outcome assessment indicators were analyzed using RevMan 5.3 software. RESULTS: Three randomized controlled trials, two prospective studies, and 26 retrospective studies were included in the current research. The results of the meta-analysis revealed significant differences between the vancomycin and control groups (non-vancomycin group) concerning the incidence of SSI (risk ratio = 0.39, 95% confidence interval = 0.28-0.55, Z = 5.46), indicating that local application of vancomycin powder can significantly reduce the incidence of SSI. CONCLUSION: Local application of vancomycin powder is an effective and safe method to prevent SSI after spinal surgeries.

17.
Opt Express ; 28(13): 18969-18985, 2020 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-32672184

RESUMO

High resolution, real-time three-dimensional (3D) measurement plays an important role in many fields. In this paper, a multi-directional dynamic real-time phase measurement profilometry based on improved optical flow is proposed. In a five-step phase shifting dynamic measurement, pixel matching is needed to make the pixels one-to-one corresponding in five patterns. However, in the frequently-used pixel matching method at present, it is necessary to calculate the correlation and traverse the whole deformed pattern for the motion information of the measured object. The huge amount of computation caused by correlation computation takes up most of the time in the process of the entire 3D reconstruction, so it can not meet the requirement of real-time dynamic measurement. In order to solve the problem, the improved optical flow algorithm is introduced to replace correlation calculation in pixel matching. In one measurement, five captured patterns need to be dealt with, and the optical flow between each two adjacent frames is calculated. Then four two-dimensional vector matrices can be obtained. The vector matrices contain the complete motion information of the measured object. Experiments and simulations prove that this method can improve the efficiency of pixel matching by 42 times and 3D reconstruction by 32 times on the premise of ensuring the accuracy.

18.
Curr Microbiol ; 77(10): 2783-2791, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32535650

RESUMO

Moutai Jiuqu is a famous aromatic raw material of Maotai flavor liquor in China. It is brewed at high temperature and contains many kinds of bacteria, molds, and yeasts. There are many useful glycoside hydrolases in these microfloras, from which efficient glycoside hydrolases can be screened for biotransformation of natural saponins. In this study, an α-L-arabinofuranosidase gene (CaAraf51, 1524 bp, 507 amino acid, 55.07 kDa, and pI = 4.8) was cloned from Cellulosimicrobium aquatile Lyp51, which was isolated from the Maotai Jiuqu. The CaAraf51 was heterogeneously expressed in E. coli BL21 (DE3) and purified by N-terminal His-tag with the Ni2+-affinity column chromatography. The results show that purified CaAraf51 has a 6.8-fold purification factor and specific activity of 15 U/mg. Under optimal conditions (pH 5.0, temperature 40 °C), kinetic parameters Km of CaAraf51 for pNPαAraf and Rc were 1.1 and 0.57 mM, the Vmax were 25 and 6.25 µmol/min/mg, respectively. 90% of 0.87 mg Rc substrate can be transformed by 9.6 U purified CaAraf51 in 1 mL reaction system under suitable conditions (30 °C, pH 7.5 phosphate buffer, 1 h). In addition, we also tested the effects of metal ions and chemical agents on the activity of CaAraf51. According to systematically studied its function and enzymatic properties, CaAraf51 has excellent value and potential of biotransformation Rc into Rd.

19.
J Chem Phys ; 152(22): 224901, 2020 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-32534545

RESUMO

Creating densified and stable liquid is a straightforward strategy for the fabrication of strong and ultra-stable amorphous or glassy materials. The current study has discovered that a liquid polymeric thin film is densified under the application of a high frequency surface acoustic wave (SAW). The experimental evidence is the decrease in film thickness and the increase in refractive index, measured by ellipsometry, of polyisobutylene thin films deposited on the solid substrates, when a high frequency SAW (39.5 MHz) is applied to the system. Further investigations by polarization-resolved single molecule fluorescence microscopy have demonstrated that the rotational motion of fluorescent probes doped inside the liquid film is retarded and the dynamical heterogeneity is reduced. The results demonstrate that the application of SAW of high frequency makes the thin polymeric liquid film densified and more dynamically homogeneous.

20.
Technol Cancer Res Treat ; 19: 1533033820919759, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32419643

RESUMO

Primary brain tumors are a rare occurrence in comparison to other malignancies, the most predominant form being glioma. Commonly, exposure to ionizing radiations and inheritance of associated conditions such a neurofibromatosis and tuberous sclerosis are the most common causes of development of glioma. However, understanding of the molecular mechanisms that drive glioma development is limited. We explore the role of aberration of microRNA namely miR-494-3p through long noncoding RNA WT1-AS in the development of gliomas. In this study, we found that, levels of WT1-AS were significantly reduced in glioma tissues and cell lines. The miR-494-3p levels were negatively correlated with WT1-AS levels. The cellular proliferation and invasiveness decreased in WT1-AS transfected cell lines. Further the half maximal inhibitory concentration (IC50) of chemotherapeutic agent temozolomide was significantly reduced in the presence of WT1-AS. The cotransfection of WT1-AS and miR-494-3p reduced activation of phospho-AKT (p-AKT). Expression of miR-494-3p is modulated by binding to long noncoding RNA WT1-AS. Deregulation of WT1-AS leads to aberrant expression of miR-494-3p leading to hyperactivation of AKT. This malformation may result in altering protective immune responses in malignancies. Targeting of WT1-AS, miR-494-3p, and AKT may be novel therapeutic options in treatment of glioma.


Assuntos
Neoplasias Encefálicas/genética , Glioma/genética , MicroRNAs/genética , RNA Longo não Codificante/genética , Apoptose/fisiologia , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Glioma/metabolismo , Glioma/patologia , Humanos , MicroRNAs/metabolismo , Gradação de Tumores , RNA Longo não Codificante/metabolismo , Transdução de Sinais
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