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1.
Nanoscale ; 11(33): 15605-15611, 2019 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-31403639

RESUMO

Two-dimensional boron (borophene) features structural polymorphs and distinct in-plane anisotropy, opening opportunities to achieve tailored electronic properties by intermixing different phases. Here, using scanning tunneling spectroscopy combined with first-principles calculations, delocalized one-dimensional nearly free electron states (NFE) in the (2,3) or ß12 borophene sheet on the Ag(111) surface were observed. The NFE states emerge from a line defect in borophene, manifested as a structural unit of the (2,2) or χ3 sheet, which creates an in-plane potential well that shifts the states toward the Fermi level. The NFE states are held near the 2D plane of borophene, rather than in the vacuum region as observed in other nanostructures. Furthermore, borophene can provide a rare prototype to further study novel NFE behaviors, which may have potential applications in transport or field emission nanodevices based on boron.

2.
Cardiology ; : 1-7, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31434097

RESUMO

Several studies have indicated that early repolarization (ER) is a risk factor for ventricular tachyarrhythmias (VTAs) in acute myocardial infarction (AMI) patients. The prognostic values of ER detail characteristics except J-point morphology, and inferior leads ER location for VTAs are still unclear. We searched PubMed, Embase, and the Cochrane Library for eligible studies up to March 4, 2019. Studies to investigate the relationship between ER and the incidence of VTAs in AMI patients were extracted. A total of 10 studies with 2,672 participants were included in the analysis. ER significantly predicted the incidence of VTAs (odds ratio [OR] 3.62, 95% confidence intervals [CI] 2.77-4.73), regardless of the type of AMI. The presence of ER before AMI (OR 5.58, 95% CI 3.41 to 9.12) and after AMI (OR 3.02, 95% CI 2.19-4.15) increased the risk of VTAs. The prognostic value of ER for VTAs in the long follow-up (≥30 days) (OR 2.39, 95% CI 1.59-3.59) fell by half compared to the short follow-up duration (<30 days) (OR 4.97, 95% CI 3.48-7.09). Patients with ER displayed a higher risk of developing ventricular fibrillation (VF) (OR 6.94, 95% CI 3.87-12.43) than those without ER. However, neither J-point elevation with OR = 2.48 nor lateral leads' ER location with OR = 3.83 remarkably increased the risk of VTAs in patients with AMI. ER is significantly associated with increasing risk of VTAs, particularly VF, in AMI patients. This relationship is weaker in the 30-day follow-up and is not reinforced by J-point elevation and lateral leads' ER location.

3.
Methods Mol Biol ; 2035: 323-331, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31444759

RESUMO

Fluorescence resonance energy transfer (FRET) is a distance-dependent process by which energy is transferred from an excited donor fluorophore to an acceptor molecule when the donor and acceptor are in close proximity to each other. Depending on the assay design, FRET can provide a real-time measurement of structural integrity and dynamics of biomacromolecules in solution and is particularly suitable for studying G-quadruplex (G4) nucleic acids and their ligand interactions. FRET-based assays are ideally suited for high throughput screening (HTS) methodology because they are simple, sensitive, and easily automated. G4s are stable nucleic acid structures involved in important regulatory roles in gene replication, transcription, and genomic instability. Four-stranded G4s are promising drug targets as these non-canonical structures are enriched in oncogene promoters, 5' UTRs, and telomeres, and have been linked to regulation of gene expression in cancer and other diseases. Although molecules that bind to G4s, with subsequent influence on gene expression, have been well documented, the identification of new chemical scaffolds that potently and selectively bind to G4s and control specific gene expression are still much less common. Here, we describe a detailed protocol of a FRET-based HTS methodology to identify novel G4 ligands.

4.
Anim Reprod Sci ; 208: 106114, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31405454

RESUMO

Egg production is determined by the function of ovary and is regulated by the hypothalamic-pituitary-ovary axis. The mechanism by which the ovary regulates egg production, however, is still poorly understood. The purpose of this study is to compare the transcriptome difference in ovary of relatively greater and lesser egg producing chickens, and to screen candidate genes related to egg production. A RNA sequencing was performed to analyze and compare the mRNA in ovarian tissues of relatively greater and lesser egg producing chickens. A total of 4 431 new genes expressed in the chicken ovary were mined. There were 305 differentially expressed genes (DEGs) identified between the relatively greater and lesser egg producing hens. Gene ontology analysis identified five candidate genes related to egg production, including ZP2, WNT4, AMH, IGF1, and CYP17A1 genes. Tissue expression profiles indicated these five candidate genes were highly expressed in chicken ovarian tissues, indicating a potential role in regulating chicken ovarian function and egg production. The KEGG analysis indicated the neuroactive ligand-receptor interaction pathway might have an important function in regulation of egg production. In addition, four known pathways related to reproduction were detected, including the calcium signaling, wnt signaling pathway, focal adhesion, and cytokine-cytokine receptor interaction pathways. Results of the present study indicate gene expression differences in the ovarian tissues of relatively greater and lesser egg producing chickens, and identified five important candidate genes related to egg production, which provided a theoretical basis for improving egg production of Jinghai Yellow Chickens.

5.
Zhongguo Dang Dai Er Ke Za Zhi ; 21(8): 830-835, 2019 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-31416511

RESUMO

OBJECTIVE: To study the effects of different melatonin treatment regimens on the proliferation of neural stem cells (NSCs) and long-term histopathology in neonatal rats with hypoxic-ischemic brain damage (HIBD), and to identify better melatonin treatment regimens. METHODS: A total of 96 Sprague-Dawley rats aged 7 days were randomly divided into normal control, HIBD, single-dose immediate melatonin treatment (SDIT), and 7-day continuous melatonin treatment (7DCT) groups, with 24 rats in each group. The rat model of HIBD was prepared by isolation and electrocoagulation of the right common carotid artery as well as hypoxic treatment in a hypoxic chamber (oxygen concentration 8.00% ±â€…0.01%) for 2 hours. On day 7 after modeling, proliferating cell nuclear antigen/Nestin double-labeling immunofluorescence was used to measure the proliferation of endogenous NSCs in the subventricular zone (SVZ) and the hippocampal dentate gyrus (DG) region in 8 rats in each group, and Western blot was used to measure the protein expression of Nestin in brain. On day 28 after modeling, hematoxylin-eosin (HE) staining and Nissl staining were used to observe the changes in the histopathology and the number of pyramidal cells in the hippocampal CA1 region in 8 rats in each group. RESULTS: Immunofluorescent staining showed that compared with the HIBD group, the SDIT and 7DCT groups had a significant increase in the number of PCNA+Nestin+DAPI+ cells, and the 7DCT group had a significantly higher number than the SDIT group (P<0.01). Western blot showed that the SDIT and 7DCT groups had significantly higher protein expression of Nestin than the HIBD group, and the 7DCT group had significantly higher expression than the SDIT group (P<0.05). HE staining showed that the SDIT and 7DCT groups had alleviated cell injury, and Nissl staining showed that compared with the HIBD group, the SDIT and 7DCT groups had a significant increase in the number of pyramidal cells, and the 7DCT group had a significantly higher number than the SDIT group (P<0.01). CONCLUSIONS: Both single-dose immediate melatonin treatment and 7-day continuous melatonin treatment can promote the proliferation of endogenous NSCs and alleviate long-term histological injury in the brain of neonatal rats with HIBD. A 7-day continuous melatonin treatment has a better effect than single-dose immediate melatonin treatment.


Assuntos
Hipóxia-Isquemia Encefálica , Células-Tronco Neurais , Animais , Animais Recém-Nascidos , Encéfalo , Proliferação de Células , Melatonina , Neurônios , Ratos , Ratos Sprague-Dawley
6.
J Cell Mol Med ; 2019 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-31449347

RESUMO

This study reports the establishment of a bone marrow mononuclear cell (BMMC) 3D culture model and the application of this model to define sensitivity and resistance biomarkers of acute myeloid leukaemia (AML) patient bone marrow samples in response to Cytarabine (Ara-C) treatment. By mimicking physiological bone marrow microenvironment, the growth conditions were optimized by using frozen BMMCs derived from healthy donors. Healthy BMMCs are capable of differentiating into major hematopoietic lineages and various types of stromal cells in this platform. Cryopreserved BMMC samples from 49 AML patients were characterized for ex vivo growth and sensitivity to Ara-C. RNA sequencing was performed for 3D and 2D cultures to determine differential gene expression patterns. Specific genetic mutations and/or gene expression signatures associated with the ability of the ex vivo expansion and response to Ara-C were elucidated by whole-exome and RNA sequencing. Data analysis identified unique gene expression signatures and novel genetic mutations associated with sensitivity to Ara-C treatment of proliferating AML specimens and can be used as predictive therapeutic biomarkers to determine the optimal treatment regimens. Furthermore, these data demonstrate the translational value of this ex vivo platform which should be widely applicable to evaluate other therapies in AML.

7.
Acta Neurobiol Exp (Wars) ; 79(2): 205-216, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31342956

RESUMO

The present study aimed to identify commonalities in the microRNA (miRNA) expression profiles of the brain ischemic penumbra and the blood after hyperacute ischemic stroke and then to address whether the miRNA profile of blood has potential usefulness as a diagnostic biomarker of hyperacute ischemic stroke. Blood was collected from the jugular vein 4 h after permanent middle cerebral artery occlusion (pMCAO). After venous blood was collected, the rats were decapitated immediately, and brain ischemic penumbra samples were collected. Hematoxylin and eosin staining was used to observe the histopathological changes. Penumbra and blood miRNAs were measured by miRNA microarray and real-time polymerase chain reaction (PCR) analysis. MicroRNA profiles differed between hyperacute ischemic stroke and sham-operated rats. The expression of some miRNAs changed by more than 1.5-fold in the penumbra and blood 4 h after pMCAO; among those miRNAs, several were upregulated and several were downregulated. MiR-223-3p was found to be highly expressed in both the penumbra and the blood 4 h after pMCAO, and let-7b-3p was found to have low expression in both the penumbra and the blood 4 h after pMCAO. Moreover, miR-223-3p and let-7b-3p expression in blood and brain ischemic penumbra were positively correlated. The results show that select blood miRNAs may correlate with miRNA changes in the penumbra in a rat model of hyperacute ischemic stroke. Our findings suggest the potential usefulness of blood miR-223-3p and let-7b-3p as noninvasive bio markers for the diagnosis of hyperacute ischemic stroke.

8.
Adv Mater ; : e1900111, 2019 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-31343086

RESUMO

Halide perovskite colloidal quantum dots (CQDs) have recently emerged as a promising candidate for CQD photovoltaics due to their superior optoelectronic properties to conventional chalcogenides CQDs. However, the low charge separation efficiency due to quantum confinement still remains a critical obstacle toward higher-performance perovskite CQD photovoltaics. Available strategies employed in the conventional CQD devices to enhance the carrier separation, such as the design of type-Ⅱ core-shell structure and versatile surface modification to tune the electronic properties, are still not applicable to the perovskite CQD system owing to the difficulty in modulating surface ligands and structural integrity. Herein, a facile strategy that takes advantage of conjugated small molecules that provide an additional driving force for effective charge separation in perovskite CQD solar cells is developed. The resulting perovskite CQD solar cell shows a power conversion efficiency approaching 13% with an open-circuit voltage of 1.10 V, short-circuit current density of 15.4 mA cm-2 , and fill factor of 74.8%, demonstrating the strong potential of this strategy toward achieving high-performance perovskite CQD solar cells.

9.
Phys Rev Lett ; 122(24): 247701, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31322382

RESUMO

Controlling the direction of the magnetization by an electric field in multiferroics that are both ferroelectric and strongly ferromagnetic will open the door to the design of the next generation of spintronics and memory devices. Using first-principles simulations, we report that the discovery that the PbTiO_{3}/LaTiO_{3} (PTO/LTO) superlattice possesses such highly desired control, as evidenced by the electric-field-induced rotation of 90° and even a possible full reversal of its magnetization in some cases. Moreover, such systems also exhibit Jahn-Teller distortions, as well as orbital orderings, that are switchable by the electric field, therefore making PTO/LTO of importance for the tuning of electronic properties too. The origin for such striking electric-field controls of magnetization, Jahn-Teller deformations, and orbital orderings resides in the existence of three different types of energetic coupling: one coupling polarization with antiphase and in-phase oxygen octahedral tiltings, a second one coupling polarization with antiphase oxygen octahedra tilting and Jahn-Teller distortions, and finally a biquadratic coupling between antiphase oxygen octahedral tilting and magnetization.

10.
Molecules ; 24(14)2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31336643

RESUMO

A method for the simultaneous analysis of amoxicillin (AMO), amoxicillin metabolites, and ampicillin residues in edible chicken muscle, liver, and kidney samples via high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI/MS/MS) was developed and verified. The extraction and purification procedures involved the extraction of the sample using a liquid-liquid extraction method with acetonitrile to eliminate the proteins. The chicken tissue extract was then injected directly onto an HPLC column coupled to a mass spectrometer with an ESI(+) source. The HPLC-ESI/MS/MS method was validated according to specificity, sensitivity, linearity, matrix effects, precision, accuracy, decision limit, detection capability, and stability, as defined by the European Union and Food and Drug Administration. The linearity was desirable, and the determination coefficients (r2 values) ranged from 0.9968 and 0.9999. The limits of detection and limits of quantification were 0.10-2.20 µg/kg and 0.30-8.50 µg/kg, respectively. The decision limits were 57.71-61.25 µg/kg, and the detection capabilities were 65.41-72.50 µg/kg, and the recoveries of the four target analytes exceeded 75% at the limits of quantification and exceeded 83% at 25, 50, and 100 µg/kg (n = 6 at each level), confirming the reliability of this method for determining these analytes and providing a new detection technology. For real sample analysis, this experiment tested 30 chicken tissue samples, only one chicken muscle, liver, and kidney sample were contaminated with 5.20, 17.45, and 7.33 µg/kg of AMO values, respectively, while other target compounds were not detected in the 30 tested chicken tissue samples.

11.
Genes (Basel) ; 10(7)2019 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-31319533

RESUMO

The growth traits are important traits in chickens. Compared to white feather broiler breeds, Chinese local broiler breeds have a slow growth rate. The main genes affecting the growth traits of local chickens in China are still unclear and need to be further explored. This experiment used fast-growth and slow-growth groups of the Jinghai Yellow chicken as the research objects. Three males and three females with similar body weights were selected from the two groups at four weeks old and eight weeks old, respectively, with a total of 24 individuals selected. After slaughter, their chest muscles were taken for transcriptome sequencing. In the differentially expressed genes screening, all of the genes obtained were screened by fold change ≥ 2 and false discovery rate (FDR) < 0.05. For four-week-old chickens, a total of 172 differentially expressed genes were screened in males, where there were 68 upregulated genes and 104 downregulated genes in the fast-growth group when compared with the slow-growth group. A total of 31 differentially expressed genes were screened in females, where there were 11 upregulated genes and 20 downregulated genes in the fast-growth group when compared with the slow-growth group. For eight-week-old chickens, a total of 37 differentially expressed genes were screened in males. The fast-growth group had 28 upregulated genes and 9 downregulated genes when compared with the slow-growth group. A total of 44 differentially expressed genes were screened in females. The fast-growth group had 13 upregulated genes and 31 downregulated genes when compared with the slow-growth group. Through gene ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, many genes were found to be related to cell proliferation and differentiation, muscle growth, and cell division such as SNCG, MCL1, ARNTL, PLPPR4, VAMP1, etc. Real-time PCR results were consistent with the RNA-Seq data and validated the findings. The results of this study will help to understand the regulation mechanism of the growth and development of Jinghai Yellow chicken and provide a theoretical basis for improving the growth rate of Chinese local chicken breeds.

12.
Langmuir ; 35(25): 8325-8332, 2019 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-31149819

RESUMO

The role of the C?OH group in citric acid (CA) in the molecular coordination with Fe3O4 nanoparticles (NPs) has been elusive for a long time. In this study, attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectral deconvolution and thermogravimetric analysis (TGA) have been used to quantitatively clarify its significance in CA adsorption and its corresponding conformation. The experimental results show that the coordination and the corresponding conformation are exclusively determined by COOH not C?OH at pH 3, where its adsorption behavior conforms to the Brunauer?Emmett?Teller (BET) multilayer model with a maximal monolayer coordination number of 2.1/nm2. However, C?OH is involved in the coordination at pH 10, and CA conforms to the Langmuir monolayer model with 1.4/nm2 as its maximal monolayer coordination number, which is more stable than the COOH-only coordination. Especially, the conformational transformation is observed for the first time at pH 3, where the CA molecules adjust their conformation upon elution to maximize the utilization of the available binding sites on Fe3O4 NPs. This finding deepens the understanding on the fundamental mechanism for the interaction between the C?OH and COOH groups containing the organic ligand and metal oxide.

13.
Heart Rhythm ; 16(9): 1383-1391, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31150819

RESUMO

BACKGROUND: Subcutaneous nerve stimulation (ScNS) damages the stellate ganglion and improves rhythm control of atrial fibrillation (AF) in ambulatory dogs. OBJECTIVE: The purpose of this study was to test the hypothesis that thoracic ScNS can improve rate control in persistent AF. METHODS: We created persistent AF in 13 dogs and randomly assigned them to ScNS (n = 6) and sham control (n = 7) groups. 18F-2-Fluoro-2-deoxyglucose positron emission tomography/magnetic resonance imaging of the brain stem was performed at baseline and at the end of the study. RESULTS: The average stellate ganglion nerve activity reduced from 4.00 ± 1.68 µV after the induction of persistent AF to 1.72 ± 0.42 µV (P = .032) after ScNS. In contrast, the average stellate ganglion nerve activity increased from 3.01 ± 1.26 µV during AF to 5.52 ± 2.69 µV after sham stimulation (P = .023). The mean ventricular rate during persistent AF reduced from 149 ± 36 to 84 ± 16 beats/min (P = .011) in the ScNS group, but no changes were observed in the sham control group. The left ventricular ejection fraction remained unchanged in the ScNS group but reduced significantly in the sham control group. Immunostaining showed damaged ganglion cells in bilateral stellate ganglia and increased brain stem glial cell reaction in the ScNS group but not in the control group. The 18F-2-fluoro-2-deoxyglucose uptake in the pons and medulla was significantly (P = .011) higher in the ScNS group than the sham control group at the end of the study. CONCLUSION: Thoracic ScNS causes neural remodeling in the brain stem and stellate ganglia, controls the ventricular rate, and preserves the left ventricular ejection fraction in ambulatory dogs with persistent AF.

14.
Acta Cytol ; 63(4): 340-346, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31163417

RESUMO

Neuroendocrine tumors (NET) and carcinomas (NEC) of the breast are rare diseases, but NEC has attracted attention in both cytopathology and surgical pathology because of its specific management and prognosis. Fine-needle aspiration biopsy (FNAB) cytology can make the diagnosis in many cases particularly with high-grade NEC, with definitive diagnosis based on histopathology and immunohistochemistry. This review describes the characteristics of the disease based on the WHO classification 2012 and recent literature and -includes discussion related to the International Academy of Cytology Yokohama System of Reporting Breast FNAB -cytology.


Assuntos
Adenocarcinoma/patologia , Neoplasias da Mama/patologia , Carcinoma Neuroendócrino/patologia , Citodiagnóstico/métodos , Adenocarcinoma/cirurgia , Biópsia por Agulha Fina , Neoplasias da Mama/cirurgia , Carcinoma Neuroendócrino/cirurgia , Feminino , Humanos , Valor Preditivo dos Testes
15.
Parasit Vectors ; 12(1): 302, 2019 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-31200771

RESUMO

BACKGROUND: Tissue transglutaminase (tTG)-regulating IL-13 plays an important role in the pathogenesis of liver fibrosis resulting from Schistosoma japonicum (Sj) infection. IL-33 and its receptor ST2 are involved in Th2-biased immune responses through the release of IL-5 and IL-13 and subsequent hepatic granuloma pathology induced by Sj infection. However, the relationship between tTG, IL-33/ST2, and liver fibrosis during Schistosoma infection has not been established. RESULTS: This study investigated the link between tTG and IL-33/ST2 in the induction of liver fibrogenesis during Sj infection in mice. The extent of liver fibrosis coincided with an increase in tTG and IL-33/ST2 expression in the liver of infected mice between five to eight weeks, with a peak of correlation at six weeks after Sj infection. The inhibition of tTG activity through cystamine administration or gene knockout alleviated the level of TLR4, NF-κB pathway molecules, IL-33/ST2, and the severity of liver fibrosis resulting from Sj infection. CONCLUSIONS: These results indicate that during Sj infection tTG may control liver fibrosis at least partially through TLR4, NF-κB pathway activation and then IL-33/ST2. tTG, IL-33 or ST2 might be promising drug targets against liver fibrosis induced by Sj infection.


Assuntos
Proteínas de Ligação ao GTP/genética , Proteína 1 Semelhante a Receptor de Interleucina-1/metabolismo , Interleucina-33/metabolismo , Cirrose Hepática/enzimologia , Esquistossomose Japônica/imunologia , Transglutaminases/genética , Animais , Cistamina/administração & dosagem , Sistemas de Liberação de Medicamentos , Feminino , Proteínas de Ligação ao GTP/imunologia , Regulação da Expressão Gênica , Técnicas de Inativação de Genes , Fígado/parasitologia , Fígado/patologia , Cirrose Hepática/parasitologia , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Schistosoma japonicum , Esquistossomose Japônica/patologia , Transglutaminases/imunologia
16.
Phys Rev Lett ; 122(19): 196801, 2019 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-31144949

RESUMO

Atomic scale engineering of two-dimensional materials could create devices with rich physical and chemical properties. External periodic potentials can enable the manipulation of the electronic band structures of materials. A prototypical system is (3×3)-silicene/Ag(111), which has substrate-induced periodic modulations. Recent angle-resolved photoemission spectroscopy measurements revealed six Dirac cone pairs at the Brillouin zone boundary of Ag(111), but their origin remains unclear [Proc. Natl. Acad. Sci. USA 113, 14656 (2016)]. We used linear dichroism angle-resolved photoemission spectroscopy, the tight-binding model, and first-principles calculations to reveal that these Dirac cones mainly derive from the original cones at the K (K^{'}) points of free-standing silicene. The Dirac cones of free-standing silicene are split by external periodic potentials that originate from the substrate-overlayer interaction. Our results not only confirm the origin of the Dirac cones in the (3×3)-silicene/Ag(111) system, but also provide a powerful route to manipulate the electronic structures of two-dimensional materials.

17.
Nano Lett ; 19(6): 3480-3489, 2019 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-31091110

RESUMO

A proper immune response is key for the successful implantation of biomaterials, and designing and fabricating biomaterials to regulate immune responses is the future trend. In this work, three different nanostructures were constructed on the surface of titanium using a hydrothermal method, and through a series of in vitro and in vivo experiments, we found that the aspect ratio of nanostructures can affect the elastic modulus of a material surface and further regulate immune cell behaviors. This work demonstrates that nanostructures with a higher aspect ratio can endow a material surface with a lower elastic modulus, which was confirmed by experiments and theoretical analyses. The deflection of nanostructures under the cell adsorption force is a substantial factor in stretching macrophages to enhance cell adhesion and spreading, further inducing macrophage polarization toward the M1 phenotype and leading to intense immune responses. In contrast, a nanostructure with a lower aspect ratio on a material surface leads to a higher surface elastic modulus, making deflection of the material difficult and creating a surface that is not conducive to macrophage adhesion and spreading, thus reducing the immune response. Moreover, molecular biology experiments indicated that regulation of the immune response by the elastic modulus is primarily related to the NF-κB signaling pathway. These findings suggest that the immune response can be regulated by constructing nanostructural surfaces with the proper elastic modulus through their influence on cell adhesion and spreading, which provides new insights into the surface design of biomaterials.

18.
J Am Heart Assoc ; 8(10): e012327, 2019 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-31070083

RESUMO

Background We previously reported that vascular smooth muscle cells ( VSMC s) from spontaneously hypertensive rats ( SHR s) show the increased expression of complement 3 (C3) and the synthetic phenotype. We targeted the SHR C3 gene (C3 knockout [C3 KO] SHRs ) by the zinc finger gene editing method. In the current study, we investigated the mechanisms underlying the increased expression of C3 and the role of endogenous C3 in the synthetic phenotype of SHR VSMC s in comparison to cells from Wistar-Kyoto ( WKY) rats and C3 KO SHR s. Methods and Results Nonmuscle myosin heavy chain staining of aortas from SHR s at 1 day after birth was stronger in comparison to WKY rats and C3 KO SHR s. DNA synthesis in VSMC s from SHR s was significantly higher in comparison to WKY rats and C3 KO SHR s. Immunohistochemical staining of renin and liver X receptor α in VSMC s from SHR s was stronger in comparison to WKY rats and C3 KO SHR s. The expression of renin, Krüppel-like factor 5, and liver X receptor α proteins in VSMC s from SHR s was significantly higher in comparison to WKY rats and C3 KO SHR s. The expression of synthetic phenotype markers osteopontin, matrix gla, and l-caldesmon, growth factors transforming growth factor-ß1 and platelet-derived growth factor-A, transcription factors Krüppel-like factor 5 and liver X receptor α, and angiotensinogen mRNA s in VSMC s from SHR s was significantly higher in comparison to WKY rats and C3 KO SHR s. The expression of miR-145 mRNA in VSMC s from SHR s was suppressed in comparison to cells from WKY rats. miR-145 inhibitor significantly increased the expression of C3 in VSMC s from WKY rats, but not in cells from SHR s. Conclusions These findings indicate that the increased C3 with the suppression of miR-145 induces the synthetic phenotype through Krüppel-like factor 5 and the activation of the renin-angiotensin system through liver X receptor α in VSMC s from SHR s.

19.
J Phys Chem Lett ; 10(12): 3248-3253, 2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-31084011

RESUMO

Room-temperature-operated continuous-wave lasers have been intensively pursed in the field of on-chip photonics. The realization of a continuous-wave laser strongly relies on the development of gain materials. To date, there is still a huge gap between the current gain materials and commercial requirements. In this work, we demonstrate continuous-wave lasers at room temperature using rationally designed in situ fabricated perovskite quantum dots in polyacrylonitrile films on a distributed feedback cavity. The achieved threshold values are 15, 24, and 58 W/cm2 for green, red, and blue lasers, respectively, which are one order lower than the reported values for the conventional CdSe quantum dot-based continuous-wave laser. Except for the high photoluminescence quantum yields, smooth surface, and high thermal conductivity of the resulting films, the key success of an ultralow laser threshold can be explained by the interaction of polyacrylonitrile and perovskite induced "charge spatial separation" effects. This progress opens up a door to achieve on-chip continuous-wave lasers for photonic applications.

20.
Emerg Infect Dis ; 25(6): 1127-1135, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31107230

RESUMO

During July 2007-June 2015, we enrolled 4,225 hospitalized children with pneumonia in a study to determine the seasonality of respiratory syncytial virus (RSV) infection in Beijing, China. We defined season as the period during which >10% of total PCRs performed each week were RSV positive. We identified 8 distinctive RSV seasons. On average, the season onset occurred at week 41 (mid-October) and lasted 33 weeks, through week 20 of the next year (mid-May); 97% of all RSV-positive cases occurred during the season. RSV seasons occurred 3-5 weeks earlier and lasted ≈6 weeks longer in RSV subgroup A-dominant years than in RSV subgroup B-dominant years. Our analysis indicates that monitoring such RSV subgroup shifts might provide better estimates for the onset of RSV transmission. PCR-based tests could be a flexible or complementary way of determining RSV seasonality in locations where RSV surveillance is less well-established, such as local hospitals throughout China.

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