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1.
Financ Res Lett ; : 101783, 2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-33013239

RESUMO

This study investigates the impact of economic uncertainty due to the coronavirus (COVID-19) pandemic on the industrial economy in the US in terms of the interdependence and causality relationship. We apply wavelet coherence analysis to economic policy uncertainty (EPU) data and monthly sector volatility of the S&P 500 index from January 2008 to May 2020. The results reveal that EPU in terms of COVID-19 has influenced the sector volatility more than the global financial crisis (GFC) for all sectors. Furthermore, EPU leads the volatility of all sectors during COVID-19 pandemic, while some sector's volatilities lead EPU during the GFC.

2.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 28(5): 1762-1768, 2020 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-33067987

RESUMO

OBJECTIVE: To investigate the effect of dasatinib on the expansion of NK cells in vitro, as well as the subsets, receptor expression and cytotoxic function of NK cells. METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated from healthy adult volunteers and cultured with SCGM added IL-2 and IL-15 for expansion of NK cells. In this culture system, dasatinib of different concentrations were added. Cell counting and phenotyping by flow cytometry were used to evaluate the amplification efficiency of NK cells. FCM was used to detect the expression of receptors on the surface of NK cells and the distribution of subsets. Subsequently, degranulation assay and CFSE/7AAD based cytotoxicity assay were used to detect the effects of dasatinib on NK cytotoxicity against leukemia cell line K562 cells. RESULTS: The expansion efficiency of NK cells in vitro could be increased by dasatinib at the concentration range of 5-50 nmol/L, and the expansion efficiency of NK cells reached the peak at 20 nmol/L of dasatinib. The NK cytotoxicity against K562 cells in dasatinib cultured group at the concentration of 20 nmol/L was significantly higher than that in control group. For the cells cultured by disatinib in vitro, the MFI of CD226, NKP46 and NKG2D was up-regulated; the ratio of NKG2A+CD57- subset was down-regulated, while the ratio of NKG2A-CD57+ subset was up-regulated.The degranulation response of NKG2A-CD57+ NK cells to K562 cells was stronger than that of NKG2A+CD57- NK cells. CONCLUSION: The results shows that appropriate dose of dasatinib(20 nmol/L) can increases the amplification efficiency of NK cells, simultaneously up-regulates the expression of NK activating receptors and increases the NKG2A-CD57+ subset, which lead to the enhancement of NK cytotoxicty against leukemia cell lines.

4.
J Am Chem Soc ; 2020 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-33044819

RESUMO

Recent advances in spherical mesoporous metal oxides (SMMOs) have demonstrated their enormous potential in a large variety of research fields. However, a direct creation of these materials with precise control on their key shape features, particularly pore architectures, remains a major challenge as compared to the widely explored counterpart of silica. Here, using Al2O3 as an example, we identified that deposition kinetics in solution played an essential role in the construction of different SMMOs. Specifically, a controlled Al3+ precipitation is critical to maintaining the electrostatic interaction between the inorganic precursors and the molecular templates, thereby achieving a designable assembly of these two components toward uniform mesoporous Al2O3-based nanospheres. We demonstrated that such a synthesis strategy is not only able to precisely control the channel orientations from concentric to radial and dendritic, a synthesis capability impeded so far for SMMOs, but is readily applicable to other metal oxides. Our study showed that the growth-kinetics control is a simple but powerful synthesis protocol and opened up a multifunctional platform to achieve systematic design of SMMOs for their future applications.

5.
Acta Biomater ; 2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33045399

RESUMO

Stimulus-responsive nanosystem is a powerful method to improve the bioavailability and reduce the side effects of anticancer agents. In the present study, a customized dual pH-responsive micellar nanoplatform (DOX+LAP-M) based on polycarbonate-doxorubicin conjugate micelles was prepared to co-deliver the chemotherapeutic agent lapatinib for inhibiting tumor growth and metastasis. DOX+LAP-M micelles with spherical morphology had a size of ∼112 nm and had an initial negative surface charge, which are favorable characteristics for long-term circulation in the blood. Once the micelles accumulated in tumor tissues, the intrinsic tumor extracellular acidity triggered the charge switch of DOX+LAP-M micelles from -1 to 9 mV, thereby facilitating cell internalization and tumor penetration. Subsequently, the pH-sensitive micellar core accelerated the release of doxorubicin and lapatinib in the acidic intracellular environment. DOX+LAP-M micelles effectively inhibited the proliferation, migration, and invasion of 4T1 cells in vitro; furthermore, the administration of DOX+LAP-M micelles in 4T1 xenograft-bearing mice suppressed solid tumor growth with an inhibitory rate of 90.2% and significantly decreased pulmonary metastatic nodules, without significant systemic toxicity. This multifunctional micellar system has high potential for clinical cancer therapy.

6.
Carbohydr Polym ; 250: 116979, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33049867

RESUMO

In this work, 3, 3'-dithiobis (propanoic dihydrazide) modified and aldehyde-modified hyaluronic acid were respectively synthesized as precursor solutions to form redox and pH dual-responsive injectable hydrogels through dynamic acylhydrazone and disulfide linkages without exogenous stimulus conditions. The reversible sol-gel transition behavior of hydrogels could be repeated multiple times by adjusting DTT/H2O2 or HCl/TEA. Interestingly, the hydrogels shrank gradually when pH decreased, which improved significantly the storage modulus up to 8.4 times at pH 2. Furthermore, the hydrogel presented acid-switchable shape-recovery characteristics of self-healing by a dynamic recombination of acylhydrazone bonds. Moreover, the osmotic driving force derived from inner and outer concentration difference also affected the characteristic. The controlled release of bovine serum albumin (BSA) encapsulated in this hydrogel could be achieved in vitro under simulated pH/redox intracellular and intercellular microenvironment. This hydrogel could also promote chondrocytes proliferation.

7.
World J Gastroenterol ; 26(30): 4479-4488, 2020 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-32874059

RESUMO

BACKGROUND: Patients with hepatitis B virus-associated acute-on-chronic liver failure (HBV-ACLF) present a complex and poor prognosis. Systemic inflammation plays an important role in its pathogenesis, and interleukin-6 (IL-6) as a pro-inflammatory cytokine is related with severe liver impairment and also plays a role in promoting liver regeneration. Whether serum IL-6 influences HBV-ACLF prognosis has not been studied. AIM: To determine the impact of serum IL-6 on outcome of patients with HBV-ACLF. METHODS: We performed a retrospective study of 412 HBV-ACLF patients. The findings were analyzed with regard to mortality and the serum IL-6 level at baseline, as well as dynamic changes of serum IL-6 within 4 wk. RESULTS: The serum IL-6 level was associated with mortality. Within 4 wk, deceased patients had significantly higher levels of IL-6 at baseline than surviving patients [17.9 (7.3-57.6) vs 10.4 (4.7-22.3), P = 0.011]. Patients with high IL-6 levels (> 11.8 pg/mL) had a higher mortality within 4 wk than those with low IL-6 levels (≤ 11.8 pg/mL) (24.2% vs 13.2%, P = 0.004). The odds ratios calculated using univariate and multivariate logistic regression were 2.10 (95% confidence interval [CI]: 1.26-3.51, P = 0.005) and 2.11 (95%CI: 1.15-3.90, P = 0.017), respectively. The mortality between weeks 5 and 8 in patients with high IL-6 levels at 4 wk was 15.0%, which was significantly higher than the 6.6% mortality rate in patients with low IL-6 levels at 4 wk (hazard ratio = 2.39, 95%CI: 1.05-5.41, P = 0.037). The mortality was 5.0% in patients with high IL-6 levels at baseline and low IL-6 levels at 4 wk, 7.5% in patients with low IL-6 levels both at baseline and at 4 wk, 11.5% in patients with low IL-6 levels at baseline and high IL-6 levels at 4 wk, and 16.7% in patients with high IL-6 levels both at baseline and at 4 wk. The increasing trend of the mortality rate with the dynamic changes of IL-6 was significant (P for trend = 0.023). CONCLUSION: A high level of serum IL-6 is an independent risk factor for mortality in patients with HBV-ACLF. Furthermore, a sustained high level or dynamic elevated level of serum IL-6 indicates a higher mortality.

8.
Artif Cells Nanomed Biotechnol ; 48(1): 1114-1124, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32880192

RESUMO

In this paper, we developed a novel strategy of preparing doxorubicin (DOX) nanocrystal (NC) exerting spherical particles with a diameter of 102 nm, which experienced following coating of chondroitin sulphate derivative (CSOA) shell via electrostatic and hydrophobic interactions. Such multifunctional outerwear resulted in drug nanocapsules with high drug loading content up to 70% and high colloidal stability under physiological conditions. It exhibited accelerated drug release behaviour when dispersing in hyaluronidase (HAase) containing medium or incubated with cancer cells. CSOA/NCs were effectively taken up by cancer cells via CD44 receptor-mediated endocytosis, but were rarely internalised into normal fibroblasts. With the comparison of typical drug-loaded micelles system (DOX/PEG-PCL), CSOA/NCs showed greater inhibition to cancer cells due to the targeted and sensitive drug delivery.

9.
J Mater Chem B ; 2020 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-32895679

RESUMO

Although there have been many reports on the use of crosslinked hyaluronic acid and gelatin derivatives as injectable hydrogels in cartilage tissue engineering, however, almost no reports have analyzed the kinds of bonding intensity that were most conducive for the maintenance of cartilage phenotypes. Herein, the biomimetic composite hydrogels based on thiolated hyaluronic acid and modified gelatin derivatives with physical mixed, weak, and strong bonding intensity were fabricated, wherein the thiolated hyaluronic acid ensured the basic network structure of composite hydrogels, and gelatin derivatives endowed the bioactivity to hydrogels. These physicochemical properties of composite hydrogels implied that strong bonding intensity (HA-GSH) contributed to the maintenance of a more uniform pore structure, and increased the ability of water retention and resistance to degradation. Further immunohistochemical and RT-PCR analyses demonstrated that the HA-GSH hydrogel greatly improved the expression level of the associated cartilage matrix and the possibility of hyaline cartilage formation in comparison to the physically blended HA-Gel gel and weak bonding crosslinked HA-GMA gel. Overall, all results proved that strong bonding intensity of the disulfide bonds in the HA-GSH hydrogel was more beneficial for the proliferation of chondrocytes and the maintenance of the hyaline cartilage phenotype, which might provide valuable inspiration for designing cartilage repair scaffolds.

10.
Artigo em Inglês | MEDLINE | ID: mdl-32902746

RESUMO

In this study, the enhanced trichloroethylene (TCE) degradation performance was investigated by polyvinyl alcohol coated calcium peroxide nanoparticles (PVA@nCP) as an oxidant in Fe(II)-based catalytic systems. The nanoscale iron sulfide (nFeS), having an average particle size of 115.4 nm, was synthesized in the laboratory and characterized by SEM, TEM, HR-TEM along with EDS elemental mapping, XRD, FTIR, ICP-OES, and XPS techniques. In only ferrous iron catalyzed system (PVA@nCP/Fe(II)), TCE degradation was recorded at 58.9% in 6 h. In comparison, this value was increased to 97.5% or 99.7% with the addition of citric acid (CA) or nFeS in PVA@nCP/Fe(II) system, respectively. A comparative study was performed with optimum usages of chemical reagents in both PVA@nCP/Fe(II)/CA and PVA@nCP/Fe(II)/nFeS systems. Further, the probe compounds tests and electron paramagnetic resonance (EPR) analysis confirmed the generation of reactive oxygen species. The scavenging experiments elucidated the dominant role of HO• to TCE degradation, particularly in PVA@nCP/Fe(II)/nFeS system. Both CA and nFeS strengthened PVA@nCP/Fe(II) system, but displayed completely different mechanisms in the enhancement of active radicals generation; hence, their different contribution to TCE degradation. The acidic environment was favorable for TCE degradation, and a high concentration of HCO3- inhibited TCE removal in both systems. Conclusively, compared to PVA@nCP/Fe(II)/nFeS system, PVA@nCP/Fe(II)/CA system resulted in encouraging TCE degradation outcomes in actual groundwater, showing great potential for prolonged benefits in the remediation of TCE polluted groundwater. Graphical abstract.

11.
ACS Nano ; 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32902955

RESUMO

Metal-air batteries are potential candidates for post-lithium energy storage devices due to their high theoretical energy densities. However, our understanding to the electrochemistry of metal-air batteries is still in its infancy. Herein we report in-situ studies in the Na-O2/CO2 (O2 and CO2 mixture) and Na-O2 batteries with either carbon nanotubes (CNTs) or Ag nanowires as the air cathode medium in an advanced aberration corrected environmental transmission electron microscope. In the Na-O2/CO2/CNT nanobattery, the discharge reactions occurred in two steps: (1) 2Na+ + 2e- + O2  Na2O2; (2) Na2O2+ CO2  Na2CO3 + O2; concurrently a parasitic Na plating reaction took place. The charge reaction proceeded via: (3) 2Na2CO3 + C → 4Na+ + 3CO2 + 4e-. In the Na-O2/CO2/Ag nanobattery, the discharge reactions were essentially the same as the Na-O2/CO2/CNT nanobattery, however, the charge reaction in the former was very sluggish, suggesting that direct decomposition of Na2CO3 is difficult. In the Na-O2 battery, the discharge reaction occurred via reaction (1), but the reverse reaction was very difficult, indicating the sluggish decomposition of Na2O2. Overall the Na-O2/CO2/CNT nanobattery exhibited much better cyclability and performance than the Na-O2/CO2/Ag and the Na-O2/CNT nanobatteries, underscoring the importance of carbon and CO2 in facilitating the Na-O2 nanobatteries. Our study provides important understanding to the electrochemistry of the Na-O2/CO2 and Na-O2 nanobatteries, which may help the development of high performance Na-O2/CO2 and Na-O2 batteries for energy storage applications.

12.
Int J Nanomedicine ; 15: 6311-6324, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32922003

RESUMO

Background: Hyaluronic acid (HA) is a major component of extracellular matrix (ECM) and its over expression in tumor tissues contributes to the increase of interstitial fluid pressure (IFP) and hinders the penetration of nanoparticles into solid tumors. Materials and Methods: We here reported a tumoral microenvironment responsive multistage drug delivery system (NPs-EPI/HAase) which was formed layer by layer via electrostatic interaction with epirubicin (EPI)-loaded PEG-b-poly(2-(diisopropylamino)ethyl methacrylate)-b-poly(2-guanidinoethylmethacrylate) (mPEG-PDPA-PG, PEDG) micelles (NPs-EPI) and hyaluronidase (HAase). In this paper, we focused on the hyaluronidase-combined nanoparticles (NPs-EPI/HAase) for tumor penetration in tumor spheroid and solid tumor models in vitro and in vivo. Results: Our results showed that NPs-EPI/HAase effectively degrade the HA in ECM and facilitate deep penetration of NPs-EPI into solid tumor. Moreover, NPs-EPI mainly employed clathrin-mediated and macropinocytosis-mediated endocytic pathways for cellular uptake and were subsequently directed to the lysosomes for further drug release triggered by proton sponge effect. Compared with NPs-EPI, the HAase coating group showed an enhanced tumoral drug delivery efficacy and inhibition of tumor growth. Conclusion: Overall, our studies demonstrated that coating nanoparticles with HAase can provide a simple but efficient strategy for nano-drug carriers to enhance solid tumor penetration and chemotherapeutic efficacy.

13.
Ultrason Sonochem ; 70: 105347, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32956936

RESUMO

As a non-thermal processing method, the ultrasound treatment prior to the frying process has been demonstrated with great potential in reducing the oil absorption of fried food. This research aimed to evaluate the effect of ultrasound pretreatment on starch properties, water status, pore characteristics, and the oil absorption of potato slices. Ultrasound probe set with two power (360 W and 600 W) at the frequency of 20 kHz for 60 min was applied to perform the pretreatments. The results showed that ultrasound pretreatment led to the surface erosion of starch granules and higher power made the structure of starch disorganized. Moreover, the fraction of bound water and immobilized water were changed after ultrasonic pretreatment. Pores with the minor diameters (0.4-3 µm and 7-12 µm) were formed after ultrasound pretreatment. The penetrated surface oil (PSO) content, and structure oil (STO) content were reduced by 27.31% and 22.25% respectively with lower power ultrasound pretreatment. As the ultrasound power increased, the surface oil (SO) content and PSO content increased by 25.34% and 12.89% respectively, while STO content decreased by 38.05%. By using ultrasonic prior to frying, the quality of potato chips has been greatly improved.

14.
Proc Natl Acad Sci U S A ; 117(38): 23401-23407, 2020 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-32887804

RESUMO

Warm periods in Earth's history offer opportunities to understand the dynamics of the Earth system under conditions that are similar to those expected in the near future. The Middle Pliocene warm period (MPWP), from 3.3 to 3.0 My B.P, is the most recent time when atmospheric CO2 levels were as high as today. However, climate model simulations of the Pliocene underestimate high-latitude warming that has been reconstructed from fossil pollen samples and other geological archives. One possible reason for this is that enhanced non-CO2 trace gas radiative forcing during the Pliocene, including from methane (CH4), has not been included in modeling. We use a suite of terrestrial biogeochemistry models forced with MPWP climate model simulations from four different climate models to produce a comprehensive reconstruction of the MPWP CH4 cycle, including uncertainty. We simulate an atmospheric CH4 mixing ratio of 1,000 to 1,200 ppbv, which in combination with estimates of radiative forcing from N2O and O3, contributes a non-CO2 radiative forcing of 0.9 [Formula: see text] (range 0.6 to 1.1), which is 43% (range 36 to 56%) of the CO2 radiative forcing used in MPWP climate simulations. This additional forcing would cause a global surface temperature increase of 0.6 to 1.0 °C, with amplified changes at high latitudes, improving agreement with geological evidence of Middle Pliocene climate. We conclude that natural trace gas feedbacks are critical for interpreting climate warmth during the Pliocene and potentially many other warm phases of the Cenezoic. These results also imply that using Pliocene CO2 and temperature reconstructions alone may lead to overestimates of the fast or Charney climate sensitivity.

16.
Int Heart J ; 61(5): 872-878, 2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-32921669

RESUMO

In-stent restenosis (ISR) still exists after drug-eluting stent (DES) implantation, even up to one year. The incidence and risk factors for neoatherosclerosis in patients with early ISR have not yet been elucidated. Here, we used optical coherence tomography (OCT) to evaluate the incidence and predictors of neoatherosclerosis in patients with early ISRs.OCT was performed on ISR lesions in 185 patients in order to detect neoatherosclerosis. The median follow-up was 180 days, and neoatherosclerosis was detected in 37% of early ISR lesions. According to the presence of neoatherosclerosis, patients with ISR were divided into two groups: neoatherosclerosis (group A, n = 69) and non-neoatherosclerosis (group B, n = 116) groups.The risk factors were similar, except for hypercholesterolemia. Moreover, the tissue characteristics were not significantly different between patients with and without neoatherosclerosis. Follow-up low-density lipoprotein-cholesterol (LDL-C) levels were divided into three grades (LDL < 70 mg/dL, 70 mg/dL≤ LDL < 100 mg/dL, and LDL ≥ 100 mg/dL). The incidence of neoatherosclerosis was significantly lower (23% versus 57%, P < 0.0001) in the LDL < 70 mg/dL group. There was no significant difference in the incidence of neoatherosclerosis in patients with lipid levels between 70 and 100 mg/dL (P = 0.53). However, neoatherosclerosis was significantly more common in patients with a follow-up LDL-C level > 100 mg/dL (45% versus 15%, P < 0.0001).In patients with early ISR lesions, the LDL-C levels may be related to the formation and progression of early neoatherosclerosis, and poor LDL-C control may be a risk factor for the occurrence of early-stage neoatherosclerosis following DES implantation.


Assuntos
LDL-Colesterol/sangue , Doença da Artéria Coronariana/epidemiologia , Reestenose Coronária/epidemiologia , Stents Farmacológicos , Hipercolesterolemia/epidemiologia , Neointima/epidemiologia , Idoso , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/cirurgia , Reestenose Coronária/diagnóstico por imagem , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hipercolesterolemia/sangue , Hipercolesterolemia/tratamento farmacológico , Incidência , Masculino , Pessoa de Meia-Idade , Neointima/diagnóstico por imagem , Fatores de Risco , Tomografia de Coerência Óptica
17.
Math Biosci Eng ; 17(4): 3450-3477, 2020 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-32987538

RESUMO

In the field of remote sensing image processing, the classification of hyperspectral image (HSI) is a hot topic. There are two main problems lead to the classification accuracy unsatisfactory. One problem is that the recent research on HSI classification is based on spectral features, the relationship between different pixels has been ignored; the other is that the HSI data does not contain or only contain a small amount of labeled data, so it is impossible to build a well classification model. To solve these problems, a dual-channel CNN model has been proposed to boost its discriminative capability for HSI classification. The proposed dual-channel CNN model has several distinct advantages. Firstly, the model consists of spectral feature extraction channel and spatial feature extraction channel; the 1-D CNN and 3-D CNN are used to extract the spectral and spatial features, respectively. Secondly, the dual-channel CNN have been used for fusing the spatial-spectral features, the fusion feature is input into the classifier, which effectively improves the classification accuracy. Finally, due to considering the spatial and spectral features, the model can effectively solve the problem of lack of training samples. The experiments on benchmark data sets have demonstrated that the proposed dual-channel CNN model considerably outperforms other state-of-the-art method.

20.
Cell Biol Int ; 2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32910511

RESUMO

Circular RNA (circRNA) is a novel noncoding RNA that is mostly found in humans and animals. Although the flux of circRNA research has increased in recent years, its precise function is still unclear. Some studies demonstrate that circRNAs can function as microRNA (miRNA) sponges involved in the regulation of competitive endogenous RNAs networks and play a crucial role in many biological processes. Other studies show that circRNAs play multiple biological roles in gastrointestinal diseases. However, the expression characteristics and function of circRNA in intestinal mucosal injury and repair after severe burn have not been reported. This study aims to screen differentially expressed circRNAs in intestinal mucosal injury and repair after severe burns and understand their underlying mechanisms. To test our hypothesis that circRNA may play a role in promoting repair in intestinal mucosa injury after severe burns, we collected the intestinal tissues of three severely burned mice and three pseudo-scalded mice and evaluated the expression of circRNAs via microarray analysis. Quantitative real-time polymerase chain reaction was also used to validate the circRNA microarray data by selecting six based on different multiples, original values, and p values. The host genes of all differentially expressed circRNAs and the downstream target genes of six selected DEcircRNAs were identified by Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes pathway analysis. Meanwhile, we also created a circRNA-miRNA-mRNA network to predict the role and function of circRNAs in intestinal mucosal injury and repair after severe burns.

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