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1.
Proc Natl Acad Sci U S A ; 121(24): e2402547121, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38830097

RESUMO

This paper exploits the potential of Global Positioning System datasets sourced from mobile phones to estimate the racial composition of road users, leveraging data from their respective Census block group. The racial composition data encompasses approximately 46 million trips in the Chicago metropolitan region. The research focuses on the relationship between camera tickets and racial composition of drivers vs. police stops for traffic citations and the racial composition in these locations. Black drivers exhibit a higher likelihood of being ticketed by automated speed cameras and of being stopped for moving violations on roads, irrespective of the proportion of White drivers present. The research observes that this correlation attenuates as the proportion of White drivers on the road increases. The citation rate measured by cameras better matches the racial composition of road users on the links with cameras than do stops by police officers. This study therefore presents an important contribution to understanding racial disparities in moving violation stops, with implications for policy interventions and social justice reforms.

2.
Anal Chem ; 95(2): 966-975, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36584292

RESUMO

Clustered regularly interspaced short palindromic repeats (CRISPR)-based assays have been an emerging diagnostic technology for pathogen diagnosis. In this work, we developed a polydisperse droplet digital CRISPR-Cas-based assay (PddCas) for the rapid and ultrasensitive amplification-free detection of viral DNA/RNA with minimum instruments. LbaCas12a and LbuCas13a were used for the direct detection of viral DNA and RNA, respectively. The reaction mixtures were partitioned with a common vortex mixer to generate picoliter-scale polydisperse droplets in several seconds. The limit of detection (LoD) for the target DNA and RNA is approximately 100 aM and 10 aM, respectively, which is about 3 × 104-105 fold more sensitive than corresponding bulk CRISPR assays. We applied the PddCas to successfully detect severe acute respiratory syndrome coronavirus (SARS-CoV-2) and human papillomavirus type 18 (HPV 18) in clinical samples. For the 23 HPV 18-suspected cervical epithelial cell samples and 32 nasopharyngeal swabs for SARS-CoV-2, 100% sensitivity and 100% specificity were demonstrated. The dual-gene virus detection with PddCas was also established and verified. Therefore, PddCas has potential for point-of-care application and is envisioned to be readily deployed for frequent testing as part of an integrated public health surveillance program.


Assuntos
COVID-19 , Infecções por Papillomavirus , Humanos , DNA Viral/genética , RNA Viral/genética , Sistemas CRISPR-Cas/genética , SARS-CoV-2/genética , Papillomavirus Humano 18
3.
Biosci Biotechnol Biochem ; 84(9): 1788-1798, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32448038

RESUMO

Many phenolic compounds, derived from lignin during the pretreatment of lignocellulosic biomass, could obviously inhibit the activity of cellulolytic and hemicellulolytic enzymes. Acetosyringone (AS) is one of the phenolic compounds produced from lignin degradation. In this study, we investigated the inhibitory effects of AS on xylanase activity through kinetic experiments. The results showed that AS could obviously inhibit the activity of xylanase in a reversible and noncompetitive binding manner (up to 50% activity loss). Inhibitory kinetics and constants of xylanase on AS were conducted by the HCH-1 model (ß = 0.0090 ± 0.0009 mM-1). Furthermore, intrinsic and 8-anilino-1-naphthalenesulfonic (ANS)-binding fluorescence results showed that the tertiary structure of AS-mediated xylanase was altered. These findings provide new insights into the role of AS in xylanase activity. Our results also suggest that AS was an inhibitor of xylanase and targeting AS was a potential strategy to increase xylose production.


Assuntos
Acetofenonas/farmacologia , Endo-1,4-beta-Xilanases/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Polissacarídeos/metabolismo , Hidrólise/efeitos dos fármacos , Cinética
4.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 49(3): 397-405, 2020 05 25.
Artigo em Zh | MEDLINE | ID: mdl-32762163

RESUMO

OBJECTIVE: To evaluate the efficacy of black cohosh extracts (BCE) in improving the low estrogen status induced by postoperative gonadotropin-releasing hormone agonist (GnRHa) in patients with endometriosis. METHODS: Randomized clinical controlled trial about the improvement of low estrogen status caused by GnRHa with the treatment of BCE in patients with endometriosis after laparoscopic surgery were retrieved from Medline (Ovid), PubMed, Cochrane Library, CNKI, CBMdisc, Wanfang and VIP databases before January 2020, and meta-analysis of included studies was performed by Revman 5.3 software. RESULTS: Seven randomized controlled trials involving 745 patients were included in this study. Meta-analysis results showed that the addition of BCE did not alter hormone levels of patients, including serum estradiol levels [ MD=1.24, 95% CI(-4.58, 7.08), P>0.05] and luteinizing hormone levels [ MD=-0.02, 95% CI(-0.15, 0.11), P>0.05]. BCE effectively improved the perimenopausal symptoms induced by low estrogen status:improving hectic fever and sweating [ OR=0.1, 95% CI(0.02, 0.47), P < 0.01], reducing the occurrence of insomnia symptoms [ OR=0.23, 95% CI(0.13, 0.39), P < 0.01], improving fatigue [ OR=0.09, 95% CI(0.04, 0.20), P < 0.01], reducing the occurrence of vaginal dryness [ OR=0.04, 95% CI(0.01, 0.30), P < 0.01]. BCE affected Kupperman's menopausal index (KMI) score 12 weeks after the surgery [ MD=-11.50, 95% CI(-20.09, -2.90), P < 0.01] and KMI score 24 weeks after the surgery [ MD=-23.68, 95% CI(-39.66, -7.69), P < 0.01]. CONCLUSIONS: The limited evidence so far indicates that BCE could efficiently improve perimenopausal symptoms cause by low estrogen status of the patients recieved GnRHa treatment after surgery for endometriosis, but does not alter hormone levels of patients.


Assuntos
Cimicifuga , Endometriose , Estrogênios , Feminino , Humanos , Extratos Vegetais
5.
Med Sci Monit ; 25: 8172-8180, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31670317

RESUMO

BACKGROUND Baicalin, one of the main bioactive components extracted from the traditional Chinese medicine baical Skullcap root, has an anti-tumor activity which had been studied in several cancers. However, its role in human mesothelioma remains unknown. In this study, we investigated the anti-tumor mechanisms of baicalin in the mesothelioma cell line MESO924. MATERIAL AND METHODS Effects of baicalin on mesothelioma were assessed by measuring cell viability, apoptosis, migration, invasion, inactivation of signaling intermediates, and cell-cycle alterations. RESULTS Baicalin inhibited the proliferation, migration, and invasion of human mesothelioma cells and increased their apoptosis, all in a dose-dependent manner. Specifically, baicalin decreased the expression of p-EGFR, p-AKT, p-MAPK, p-S6, Bcl-2, and VEGF and increased the expression of Bax in mesothelioma cells. The suppressed mesothelioma cellular proliferation is due to the arrest of the S cell cycle by baicalin. Inhibition of the PI3K/AKT/mTOR signaling pathway by a PI3K/AKT/mTOR inhibitor augmented the anti-proliferation effects induced by baicalin. In addition, baicalin increased the sensitivity of MESO924 to the chemotherapeutic drugs doxorubicin, cisplatin, and pemetrexed. CONCLUSIONS These results highlight the roles of baicalin in inhibiting cell growth, migration, and invasion of mesothelioma cells while increasing apoptosis and sensitizing cells to chemotherapeutic agents through the PI3K/AKT/mTOR signaling pathway, which indicates that baicalin could be a useful drug for mesothelioma therapy.


Assuntos
Flavonoides/farmacologia , Mesotelioma/tratamento farmacológico , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , China , Flavonoides/metabolismo , Flavonoides/uso terapêutico , Humanos , Invasividade Neoplásica/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo
6.
Med Sci Monit ; 24: 4841-4850, 2018 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-30002361

RESUMO

BACKGROUND Alteration of DNA methylation of tumor suppressor genes (TSGs) is one of the most consistent epigenetic changes in human cancers. DNMTs play several important roles in DNA methylation and development of cancers. Regarding DNMTs protein expressions, little is known about the clinical significance and correlation with promoter methylation status of TSGs in human pituitary adenomas. MATERIAL AND METHODS We analyzed the protein expression of 3 DNMTs using immunohistochemistry and assessed DNA hypermethylation of RASSF1A, CDH13, CDH1, and CDKN2A (p16) in 63 pituitary adenomas. We examined associations between DNMTs expression and clinicopathological features or promoter methylation status of TSGs. RESULTS Overexpression of DNMTs was detected in pituitary adenomas. Frequencies of DNMT1 overexpression were significantly higher in macroadenomas, invasive tumors, and grade III and IV tumors. DNMT3A was frequently detected in invasive tumors and grade IV tumors. In addition, DNMT1 and DNMT3A were frequently detected in high-methylation tumors. Furthermore, in multivariate logistic regression, the significant association between DNMT1 or DNMT3A and high-methylation status persisted after adjusting for clinicopathological features. CONCLUSIONS Our findings suggested that tumor overexpression of DNMT1 and DNMT3A is associated with tumor aggressive behavior and high-methylation status in pituitary adenomas. Our data support a possible role of DNMT1 and DNMT3A in TSG promoter methylation leading to pituitary adenoma invasion and suggest that inhibition of DNMTs has the potential to become a new therapeutic approach for invasive pituitary adenoma.


Assuntos
Adenoma/genética , DNA (Citosina-5-)-Metiltransferase 1/biossíntese , DNA (Citosina-5-)-Metiltransferases/biossíntese , Metilação de DNA , Genes Supressores de Tumor , Neoplasias Hipofisárias/genética , Adenoma/enzimologia , Adenoma/metabolismo , Adenoma/patologia , Adulto , Antígenos CD , Caderinas/genética , Caderinas/metabolismo , Inibidor p16 de Quinase Dependente de Ciclina , Inibidor de Quinase Dependente de Ciclina p18/genética , Inibidor de Quinase Dependente de Ciclina p18/metabolismo , DNA/metabolismo , DNA (Citosina-5-)-Metiltransferase 1/genética , DNA (Citosina-5-)-Metiltransferase 1/metabolismo , DNA (Citosina-5-)-Metiltransferases/genética , DNA (Citosina-5-)-Metiltransferases/metabolismo , DNA Metiltransferase 3A , Epigênese Genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Hipofisárias/enzimologia , Neoplasias Hipofisárias/metabolismo , Neoplasias Hipofisárias/patologia , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo
7.
Wei Sheng Yan Jiu ; 46(1): 99-108, 2017 Jan.
Artigo em Zh | MEDLINE | ID: mdl-29903160

RESUMO

OBJECTIVE: To explore detecting methods and quality control standard system for hepatitis A virus( HAV) in water for fruits and vegetables production. METHODS: 100 µL of coliphage MS2( 2. 5 × 10~9 pfu / mL) was added into each water sample, and positively charged membrane filter method was used to capture virus. The virus extraction efficiency of each sample can be calculated according to standard curve of coliphage. Then the quality control system and real-time RT-PCR method were established. RESULTS: This research compared the extraction efficiency of HAV and coliphage MS2 which were added into the water samples at the same time. The extraction efficiency of HAV was from 1. 24% to 32. 68%, and coliphage MS2 1. 64% to 14. 24%. The efficiency met the requirements of ISO / TS 15216-2-2013. Meanwhile, the HAV in 30 water samples were detected, and one was positive. The extraction efficiency of coliphage MS2 was from1. 24% to 24. 19%, and the standard deviation was 0. 0612. CONCLUSION: This research establish a quality control system to ensure the quality of test results.


Assuntos
Contaminação de Alimentos/análise , Frutas/microbiologia , Vírus da Hepatite A/isolamento & purificação , Levivirus/genética , Controle de Qualidade , RNA Viral/análise , Reação em Cadeia da Polimerase em Tempo Real/normas , Verduras/microbiologia , Virologia/métodos , Microbiologia da Água , Microbiologia de Alimentos , Vírus da Hepatite A/genética , Humanos , RNA Viral/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Virologia/normas , Água
8.
Sci Data ; 11(1): 638, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38886400

RESUMO

Despite the importance of measuring racial-ethnic segregation and diversity in the United States, current measurements are largely based on the Census and, thus, only reflect segregation and diversity as understood through residential location. This leaves out the social contexts experienced throughout the course of the day during work, leisure, errands, and other activities. The National Experienced Racial-ethnic Diversity (NERD) dataset provides estimates of diversity for the entire United States at the census tract level based on the range of place and times when people have the opportunity to come into contact with one another. Using anonymized and opted-in mobile phone location data to determine co-locations of people and their demographic backgrounds, these measurements of diversity in potential social interactions are estimated at 38.2 m × 19.1 m scale and 15-minute timeframe for a representative year and aggregated to the Census tract level for purposes of data privacy. As well, we detail some of the characteristics and limitations of the data for potential use in national, comparative studies.


Assuntos
Diversidade Cultural , Etnicidade , Grupos Raciais , Humanos , Estados Unidos
9.
Biosensors (Basel) ; 13(2)2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36831946

RESUMO

Rapid and sensitive detection of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is essential for early diagnosis and effective treatment. Nucleic acid testing has been considered the gold standard method for the diagnosis of COVID-19 for its high sensitivity and specificity. However, the polymerase chain reaction (PCR)-based method in the central lab requires expensive equipment and well-trained personnel, which makes it difficult to be used in resource-limited settings. It highlights the need for a sensitive and simple assay that allows potential patients to detect SARS-CoV-2 by themselves. Here, we developed an electricity-free self-testing system based on reverse transcription loop-mediated isothermal amplification (RT-LAMP) that allows for rapid and accurate detection of SARS-CoV-2. Our system employs a heating bag as the heat source, and a 3D-printed box filled with phase change material (PCM) that successfully regulates the temperature for the RT-LAMP. The colorimetric method could be completed in 40 min and the results could be read out by the naked eye. A ratiometric measurement for exact readout was also incorporated to improve the detection accuracy of the system. This self-testing system is a promising tool for point-of-care testing (POCT) that enables rapid and sensitive diagnosis of SARS-CoV-2 in the real world and will improve the current COVID-19 screening efforts for control and mitigation of the pandemic.


Assuntos
COVID-19 , Humanos , SARS-CoV-2 , Autoteste , Teste para COVID-19 , Técnicas de Laboratório Clínico/métodos , Sensibilidade e Especificidade , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos
10.
J Med Chem ; 66(5): 3635-3647, 2023 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-36843292

RESUMO

To discover ulcerative colitis (UC) treatment agents, 28 oleanane-type triterpenoid saponins (1-28) including three new saponins, pulsatillosides P-R (1-3), were isolated from Pulsatilla chinensis. The isolated saponins could observably ameliorate UC by improving the intestinal epithelial cell barrier and intestinal flora in vivo. The structure-activity relationship indicated that the oligosaccharide chain at C-28 was essential for their anti-UC activities; the methyl group at the C-23 site of triterpene saponins showed important effects on anti-UC efficacy; the chain length of oligosaccharides at position C-28 had little effect on their anti-UC activities. In vivo investigation of representative saponins 1 and 13 further confirmed that 23-methyl-3,28-bisdesmosidic oleanane-type saponins inhibited the TNFα-NFκB-MLCK axis to improve the intestinal epithelial cell barrier of the colon in UC mice. These findings revealed the potential of 23-methyl-3,28-bisdesmosidic oleanane-type saponins from P. chinensis as promising candidates for the treatment of UC.


Assuntos
Colite Ulcerativa , Pulsatilla , Saponinas , Animais , Camundongos , Colite Ulcerativa/tratamento farmacológico , Saponinas/farmacologia , Saponinas/uso terapêutico , Relação Estrutura-Atividade
11.
J Phys Chem B ; 113(21): 7423-9, 2009 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-19456172

RESUMO

In this article, molecular orientation of crystalline and amorphous phases of both linear low-density polyethylene (LLDPE) and isotactic polypropylene (iPP) and epitaxy in the LLDPE/iPP blends prepared via dynamic packing injection molding have been investigated with the aid of polarized Fourier transform infrared (FTIR) spectroscopy and two-dimensional X-ray scattering (2D-WAXS). In LLDPE-rich blends, LLDPE was oriented along the shear flow direction, and iPP kept very low orientation. No epitaxial growth between LLDPE and iPP was observed. However, for the blends with LLDPE content less than 50 wt %, where iPP was the matrix and LLDPE formed the droplets, iPP was highly oriented along shear flow direction and LLDPE epitaxially grew onto iPP. The contact planes were (100)LLDPE and (010)iPP, and LLDPE molecules were about 50 degrees apart from the shear direction. The epitaxy fraction in LLDPE/iPP blends could be tentatively calculated from the values of orientation function of the LLDPE crystalline a-axis (fa) and that of crystalline b-axis (fb). Both tensile strength and tensile modulus decreased with the increase of LLDPE composition, indicating they were composition dependent, though shear-induced orientation and epitaxial crystallization might play some role. The impact strength of the blend samples reached a plateau in the LLDPE composition range of 20-50%, due to the contribution of orientation and epitaxy.

12.
J Phys Chem B ; 113(29): 9664-8, 2009 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-19569644

RESUMO

A study on the mechanism for the degraded toughness in nylon 6/clay nanocomposite is explored in this article. Such a nanocomposite exhibits lower specific essential work of fracture we and specific nonessential work of fracture betawp than its pure nylon 6 counterpart, as revealed by essential work of fracture (EWF) measurements. Furthermore, the molecular orientation in a small region (20x20 microm2) ahead of crack tip, obtained from micro-FTIR measurements for the first time, is found to be lower in the nanocomposite during crack initiation and propagation. The decreased molecular orientation, mostly resulted from severe microvoiding at crack tips, is responsible for the reduced specific essential work of fracture we. Meanwhile, the molecular orientation around crack tip also indicates that lower plastic deformation occurs in the plastic zone, which is well correlated with decreased specific nonessential work of fracture betawp in the nanocomposite.


Assuntos
Silicatos de Alumínio/química , Caprolactama/análogos & derivados , Nanoestruturas/química , Polímeros/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Caprolactama/química , Argila , Tamanho da Partícula , Propriedades de Superfície
13.
Cell Cycle ; 18(24): 3472-3490, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31713447

RESUMO

Protein kinase CK2 alpha (CK2α) is involved in the development of multiple malignancies. Overexpression of Y-box binding protein 1 (YBX1) is related to tumor proliferation, drug resistance, and poor prognosis. Studies have demonstrated that both CK2 and YBX1 could regulate the PI3K/AKT pathway. In addition, we predicted that CK2 might be the upstream kinase of YBX1 through the Human Protein Reference Database (HPRD). Herein, we hypothesize that CK2 may interact with YBX1 and they regulate the PI3K/AKT signaling pathway together. Expressions of CK2α and YBX1 in cancer cell lines were evaluated by immunoblotting. The results showed that CK2α could regulate the expression of YBX1 at the transcriptional level, which is dependent on its enzymatic activity. Synergistic effects of PI3K/AKT pathway inactivation could be observed through combined inhibition of CK2α and YBX1, and YBX1 was required for CK2α-induced PI3K/AKT pathway activation. Further results demonstrated that CK2α could interact with YBX1 and PI3K/AKT antagonist decreased cell resistance to doxorubicin induced by co-activation of CK2α and YBX1. These results indicated that combined inhibition of CK2α and YBX1 showed synergistic effects in inactivating the PI3K/AKT signaling pathway and may be one of the mechanisms involved in tumor growth and migration.


Assuntos
Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias/tratamento farmacológico , Proteína 1 de Ligação a Y-Box/genética , Caseína Quinase II/antagonistas & inibidores , Caseína Quinase II/genética , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HeLa , Células Hep G2 , Humanos , Neoplasias/genética , Neoplasias/patologia , Proteína Oncogênica v-akt/genética , Fosfatidilinositol 3-Quinases/genética , Ligação Proteica/genética , Transdução de Sinais/genética , Proteína 1 de Ligação a Y-Box/antagonistas & inibidores
14.
Zhonghua Jie He He Hu Xi Za Zhi ; 31(3): 213-7, 2008 Mar.
Artigo em Zh | MEDLINE | ID: mdl-18785522

RESUMO

OBJECTIVE: To observe the epithelial Toll like receptor (TLR)4 expression changes and the signaling pathway function after respiratory syncytial virus (RSV) infection and to explore the mechanisms of RSV-induced airway inflammation. METHODS: 9HTEo-human tracheal epithelial cell line was infected by RSV (MOI = 10), and TLR1-10 mRNA were detected by RT-PCR assay at 3 h post RSV infection. TLR4 mRNA was detected by real time Q-PCR assay at 3 h, 6 h and 9 h post RSV infection, and TLR4 protein expression and cell apoptosis were determined by flow cytometry at 24 h post RSV infection. IL-8 in supernatant was detected by ELISA after RSV-infected cells exposed to lipopolysaccharide (LPS). A normal control group and a RSV infection group were set up for the RT-PCR and flow cytometry experiments, and the data were analyzed by paired t test using GraphPad 4.0 software. A normal group, a RSV group and a UV-inactivated RSV group were set up for the real time Q-PCR, experiments, and the data were analyzed by Kruskal-Wallis test. The ELISA experiments were divided into 4 groups including a normal control, a RSV, a LPS stimulation, and a RSV plus LPS co-stimulation groups, and the data were analyzed by One-way ANOVA test. RESULTS: (1) TLR2-10 mRNA level was significantly up-regulated (t value of TLR2-10: 3.49 -14.47, P < 0.05), especially TLR-2, 6 enhanced expression, compared with the normal epithelial cells. Real time Q-PCR assay showed that TLR4 mRNA started to increase at 3hr (Kruskal-Wallis test value = 8.82, P < 0.05, n = 6) and significantly elevated at 9 hour (Kruskal-Wallis test value = 6.62, P < 0.05, n = 6). UV inactivated-RSV had no effect on the TLR4 mRNA level. (2) Flow cytometry showed that membrane TLR4 mean fluorescence intensity (MFI) increased (RSV: 1.27 +/- 0.48, normal: 0.97 +/- 0.25; t = 2.39, P > 0.05, n = 10) while cytoplasmic TLR4 MFI simultaneously decreased (RSV: 3.08 +/- 1.38, normal: 3.36 +/- 1.31, t = 2.92, P = 0.225, n = 10). Percentage of membrane TLR4-positive cells was higher in RSV infected population [RSV: (11.99 +/- 7.74)%, normal: (1.16 +/- 0.47)%, Mann-Whitney t value = 0.001, P < 0.01, n = 8], most (93.32 +/- 1.7)% of which were Annexin V positive. IL-8 was significantly induced in the RSV plus LPS costimulation group compared with RSV group (F = 59.29, P < 0.01, n = 3). CONCLUSIONS: RSV induced epithelial TLR4 up-regulation, localization changes from cytoplasm to membrane, IL-8 secretion through TLR4 signaling pathway and epithelial cell apoptosis in membrane TLR4 positive population. These results indicate TLR4 is involved in RSV-induced acute or chronic epithelial-dependent inflammation, which might contribute to acute or chronic airway inflammation.


Assuntos
Células Epiteliais/metabolismo , Infecções por Vírus Respiratório Sincicial/metabolismo , Vírus Sinciciais Respiratórios/fisiologia , Receptor 4 Toll-Like/metabolismo , Apoptose , Linhagem Celular , Humanos , Inflamação , Interleucina-8/metabolismo , RNA Mensageiro/genética , Infecções por Vírus Respiratório Sincicial/fisiopatologia , Receptor 4 Toll-Like/genética , Regulação para Cima
15.
J Phys Chem B ; 111(46): 13206-10, 2007 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-17973423

RESUMO

Irradiation of ultrahigh molecular weight polyethylene (UHMWPE) with a dose of 150 kGy by an electron beam can effectively increase the entanglement density in the amorphous phase and has little influence on the properties of the crystalline phase, which provides examples to comparatively investigate the role of lamellar coupling and entanglement density in determining the strain-hardening effect in semicrystalline polymers. The strain-hardening modulus, deduced from the Haward plots of true stress-strain curves, is inversely temperature-dependent and has a sharp transition around 65 degrees C that corresponds to the mechanical alphaI-process of the crystalline phase for both nonirradiated and irradiated samples, irrespective of the entanglement density in the amorphous phase. Lamellar coupling takes more effect in determining the strain-hardening behavior before the mechanical alphaI-process is activated. With further increasing temperature, lamellar coupling becomes weaker and the role of the entangled amorphous phase is gradually presented. However, the same temperature dependence of the strain-hardening modulus in both nonirradiated and irradiated samples indicates that the strain-hardening behavior in semicrystalline polymer is mostly determined by lamellar coupling rather than by entanglement density.

16.
J Phys Chem B ; 113(45): 14920-4, 2009 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-19839570

RESUMO

The conformational and polymorphic transformations in the melt-spun monofilament of syndiotactic polypropylene upon annealing and subsequent stretching have been first explored by micro-FTIR studies. The results indicate that annealing of as-spun monofilament gives rise to an unusual increase in the molecular orientation of helical conformations in both amorphous phase and ordered crystals as a result of structural transitions of transplanar conformations to helical ones as well as mesophase to ordered crystals. The increased molecular orientation in the annealed monofilament is mainly responsible for the enhanced strength during stretching. Furthermore, high stress exerted by the molecular chains of annealed monofilament is confirmed by the significant structural transitions opposite to that induced by annealing.

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