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1.
J Hazard Mater ; 383: 121156, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31505427

RESUMO

LaMnO3-based catalysts with perovskite structure have gained increasing interest for Hg0 oxidation owing to their excellent catalytic activity, high thermal stability and unique redox behavior. Understanding the Hg0 oxidation behavior on LaMnO3 will broaden the application of LaMnO3-based perovskites in Hg0 removal field. Density functional theory (DFT) calculations were conducted to examine the catalytic mechanism of Hg0 oxidation by HCl on LaMnO3 surface. The results indicate that Mn-terminated LaMnO3(010) surface is more active and stable than La-terminated surface. Hg0 and HgCl2 are chemisorbed on LaMnO3(010) surface. HgCl can be molecularly chemisorbed on LaMnO3(010) and serve as an intermediate in Hg0 oxidation reaction. HCl dissociatively adsorbs on LaMnO3(010) and generates surface active chlorine complexes. Langmuir-Hinshelwood mechanism, where the chemisorbed Hg0 reacts with the dissociatively adsorbed HCl, is responsible for Hg0 oxidation by HCl on LaMnO3(010). Catalytic Hg0 oxidation over the surface contains four-steps: Hg0 → Hg(ads) → HgCl(ads) → HgCl2(ads) → HgCl2, and the second step (Hg(ads) → HgCl(ads)) is the rate-determining step because of its relatively larger energy barrier (0.74 eV).

2.
J Am Coll Radiol ; 16(11S): S399-S416, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31685108

RESUMO

Renal cell carcinoma (RCC) accounts for most malignant renal tumors and is considered the most lethal of all urologic cancers. For follow-up of patients with treated or untreated RCC and those with neoplasms suspected to represent RCC, radiologic imaging is the most useful component of surveillance, as most relapses and cases of disease progression are identified when patients are asymptomatic. Understanding the strengths and limitations of the various imaging modalities for the detection of disease, recurrence, or progression is important when planning follow-up regimens. This publication addresses the appropriate imaging examinations for asymptomatic patients who have been treated for RCC with radical or partial nephrectomy, or ablative therapies. It also discusses the appropriate imaging examinations for asymptomatic patients with localized biopsy-proven or suspected RCC undergoing active surveillance. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

3.
BMC Genomics ; 20(1): 825, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31703618

RESUMO

BACKGROUND: 5-Azacytidine (5-azaC) promotes the development of 'Kyoho' grape berry but the associated changes in gene expression have not been reported. In this study, we performed transcriptome analysis of grape berry at five developmental stages after 5-azaC treatment to elucidate the gene expression networks controlling berry ripening. RESULTS: The expression patterns of most genes across the time series were similar between the 5-azaC treatment and control groups. The number of differentially expressed genes (DEGs) at a given developmental stage ranged from 9 (A3_C3) to 690 (A5_C5). The results indicated that 5-azaC treatment had not very great influences on the expressions of most genes. Functional annotation of the DEGs revealed that they were mainly related to fruit softening, photosynthesis, protein phosphorylation, and heat stress. Eight modules showed high correlation with specific developmental stages and hub genes such as PEROXIDASE 4, CAFFEIC ACID 3-O-METHYLTRANSFERASE 1, and HISTONE-LYSINE N-METHYLTRANSFERASE EZA1 were identified by weighted gene correlation network analysis. CONCLUSIONS: 5-AzaC treatment alters the transcriptional profile of grape berry at different stages of development, which may involve changes in DNA methylation.

4.
Artigo em Inglês | MEDLINE | ID: mdl-31691077

RESUMO

The previous clinical trials found that the co-administration of irinotecan with sunitinib exhibited a synergistic antitumor effect. In the current study, we aimed to investigate whether the synergistic effect is related to a potential pharmacokinetic interaction between sunitinib and irinotecan. The inhibitory effects of sunitinib on SN-38 glucuronidation were determined by measuring the formation rates for SN38 glucuronide using recombinant human UGT isoforms and human liver microsomes (HLMs) in the absence or presence of sunitinib. Our data indicated that sunitinib exhibited competitive inhibition against SN-38 glucuronidation by UGT1A1, but inhibitory effects of sunitinib were weak in pooled human liver microsomes (HLMs) (Ki = 119.00 µM) and recombinant UGT1A1 (Ki = 42.71 µM). Our further prediction study partly explains the possible mechanism of synergistic antitumor activity of sunitinib and irinotecan in the combined treatment and provides a basis for design of clinical studies for the development and optimization of this combination.

5.
Ir J Med Sci ; 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31691888

RESUMO

BACKGROUND: To explore the value of the right hemi-diaphragmatic excursion (DE) and its variation in predicting extubation outcome in mechanically ventilated patients with COPD. METHODS: All included patients with COPD received mechanical ventilation (MV) and were ready to wean from MV. After patients passed the 30 min spontaneous breathing trail (SBT), extubation was considered to be feasible, and the right DE measured by ultrasound at 0 min, 5 min, and 30 min of SBT were named as DE0, DE5, and DE30, respectively. RESULTS: Twenty-five patients succeeded extubation; 12 patients failed. The area under receiver operator characteristic curve (AUCROC) of DE30 and ΔDE30-5 (the variation between 30 and 5 min) were 0.762 and 0.835; a cutoff value of DE30 > 1.72 cm and ΔDE30-5 > 0.16 cm were associated with a successful extubation with a sensitivity of 76% and 84%, a specificity of 75% and 83.3%, respectively. The predictive probability equation of the DE30 plus ∆DE30-5 was P = 1/[1 + e-(-5.625+17.689×∆DE30-5+1.802×DE30)], a cutoff value of P > 0.626 was associated with a successful extubation with the AUCROC of 0.867, a sensitivity of 92%, and a specificity of 83.3%. CONCLUSION: The combination of DE30 and ∆DE30-5 could improve the predictive value and could be used as the predictor of extubation outcome in mechanically ventilated patients with COPD.

6.
Drug Des Devel Ther ; 13: 3693-3704, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31695336

RESUMO

Purpose: Spinal cord injury (SCI) is a relatively common, devastating traumatic condition resulting in permanent disability. In this study, the use of exosomes derived from bone mesenchymal stem cells (BMSCs-Exo) as a cell-free therapy for the treatment of SCI in rats was investigated to gain insights into their mechanisms of action. Methods: Rats were randomly divided into three groups, Sham (treated with PBS), SCI (SCI injury + PBS) and SCI + Exo (SCI injury + BMSCs-Exo). Changes in the complement system between the three groups were assessed with the use of proteomics. The proteomic data were verified using reverse transcription-polymerase chain reaction (RT-PCR). In addition, the distributions of BMSCs-Exo in rats with SCI were detected by immunofluorescence. Moreover, SCI-activated NF-κB levels were determined using Western blot. Results: SCI insult increased complement levels, including C4, C5, C6, C4 binding protein alpha and complement factor H. In contrast, the SCI + BMSCs-Exo group exhibited attenuated SCI-induced complement levels. Immunofluorescence assay results revealed that BMSCs-Exo mainly accumulated at the spinal cord injury site and were bound to microglia cells. Western blot analysis of tissue lysates showed that BMSCs-Exo treatment also inhibited SCI-activated nuclear factor kappa-B (NF-κB). Conclusion: BMSCs-Exo play a protective role in spinal cord injury by inhibiting complement mRNA synthesis and release and by inhibiting SCI-activated NF-κB by binding to microglia.

7.
Theranostics ; 9(24): 7140-7155, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31695758

RESUMO

Rationale: Peri-prosthetic osteolysis (PPO) is mainly induced by wear particles and represents the leading cause of implant failure and revision surgery. Previous studies have identified mitigation of wear particle-induced inflammation and bone resorption as the main approaches to treat PPO. Recently, wear particle-induced reduction of bone formation around the prosthesis was identified as a major factor in the development of PPO. Acetyl-11-keto-ß-boswellic acid (AKBA), a derivative of frankincense, has been shown to play a potential role in bone metabolism. However, whether AKBA enhances bone formation in wear particle-induced osteolysis remains unknown. In this study, we examined whether AKBA attenuates titanium particle-induced osteogenic reduction. Methods: Titanium particles were used to induce osteolysis in murine calvaria, and micro-CT and histological analyses were used to evaluate the results. Mouse osteoblast cells, MC3T3-E1 were co-cultured with titanium particles to determine their effect on osteoblast formation in vitro. Results: We demonstrated that AKBA treatment significantly inhibited titanium particle-induced osteogenic inhibition by enhancing osteogenesis both in vivo and in vitro. AKBA treatment also enhanced the phosphorylation of GSK-3ß, decreased the degradation of ß-catenin, and increased the translocation of ß-catenin from the cytoplasm to the nucleus. Taken together, these results showed that AKBA treatment attenuated titanium-induced osteogenic inhibition by activating the GSK-3ß/ß-catenin signaling pathway. Conclusion: These findings suggest that AKBA is a promising new target in the prevention and treatment of PPO.

8.
ISA Trans ; 2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31699400

RESUMO

This paper investigates the synchronization issue of the memristive neural networks (MNNs) with inertial terms and reaction-diffusion items. In order to smoothly derive the controller gains and obtain an excellent control effect, the desired controller that contains a discontinuous function is proposed. Moreover, by constructing a novel Lyapunov-Krasovskii functional and combining the inequality techniques, several sufficient conditions in terms of algebraic inequalities are obtained to guarantee the synchronization of the proposed drive and response systems. Finally, three numerical simulations are exploited to support the acquired theoretical results.

9.
Artigo em Inglês | MEDLINE | ID: mdl-31702970

RESUMO

There is still lack of a simple, accurate and noninvasive method for rat aortic pulse wave velocity (PWV) measurement, especially the transit distance cannot be accurately measured. Thus we aimed to derive an equation for aortic transit distance as a function of the nose-to-rump length (L), and to test the hypothesis that aortic PWV measured by new equation combined with Doppler ultrasound (the "equation method") may have stronger correlation with invasive measurements than traditional "body surface method". Two hundred male Sprague-Dawley (SD) rats (age ranged 5-24 weeks) were included in Protocol 1 and the aortic transit distances were measured post mortem. In Protocol 2, heart-femoral PWV and carotid-femoral PWV were measured by "equation method" (hfPWVE, cfPWVE), and also by traditional "body surface method" (hfPWVS, cfPWVS) in another 30 young and 28 old rats. Then these measurements were validated against invasively measured hfPWVI, cfPWVI from the same animal. Protocol 1 showed that the heart-femoral transit distance could be calculated by 0.6086×L-1.6523, the carotid-femoral transit distance by 0.4614×L+1.8335. In Protocol 2, in young rats, the Pearson r between hfPWVE, cfPWVE, hfPWVS, cfPWVS and their corresponding invasive measurement were 0.8962, 0.8509, 0.8387, 0.7828, respectively (all P<0.0001). In old group, the results were 0.8718, 0.7999, 0.8330, 0.7112, respectively (all P<0.0001). The hfPWVE and cfPWVE showed better agreement with hfPWVI and cfPWVI, and lower intra- and inter-observer variability compared with hfPWVS and cfPWVS in both groups. These findings demonstrate that this novel methodology provides a simple and reliable method for rat noninvasive aortic PWV measurement.

10.
Cell Prolif ; : e12726, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31755150

RESUMO

OBJECTIVES: In humans, non-obstructive azoospermia (NOA) is a major cause of male infertility. However, the aetiology of NOA is largely unknown. Previous studies reported that protein CK2ß was abundantly and broadly expressed in spermatogenic cells. Here, we investigate whether protein CK2ß participates in spermatogenesis. MATERIALS AND METHODS: In this study, we separated spermatogenic cells using STA-PUT velocity sedimentation, analysed the expression pattern of protein CK2ß by immunoblotting, specifically deleted Ck2ß gene in early-stage spermatogenic cells by crossing Ck2ßfl mice with Stra8-Cre+ mice and validated the knockout efficiency by quantitative RT-PCR and immunoblotting. The phenotypes of Ck2ßfl/Δ ;SCre+ mice were studied by immunohistochemistry and immunofluorescence. The molecular mechanisms of male germ cell development arrest were elucidated by immunoblotting and TUNEL assay. RESULTS: Ablation of Ck2ß gene triggered excessive germ cell apoptosis, germ cell development arrest, azoospermia and male infertility. Inactivation of Ck2ß gene caused distinctly reduced expression of Ck2α' gene and CK2α' protein. CONCLUSIONS: Ck2ß is a vital gene for germ cell survival and male fertility in mice.

11.
Prog Retin Eye Res ; : 100802, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31704338

RESUMO

The ocular lens is a unique tissue that contains an age gradient of cells and proteins ranging from newly differentiated cells containing newly synthesized proteins to cells and proteins that are as old as the organism. Thus, the ocular lens is an excellent model for studying long-lived proteins (LLPs) and the effects of aging and post-translational modifications on protein structure and function. Given the architecture of the lens, with young fiber cells in the outer cortex and the oldest cells in the lens nucleus, spatially-resolved studies provide information on age-specific protein changes. In this review, experimental strategies and proteomic methods that have been used to examine age-related and cataract-specific changes to the human lens proteome are described. Measured spatio-temporal changes in the human lens proteome are summarized and reveal a highly consistent, time-dependent set of modifications observed in transparent human lenses. Such measurements have led to the discovery of cataract-specific modifications and the realization that many animal systems are unsuitable to study many of these modifications. Mechanisms of protein modifications such as deamidation, racemization, truncation, and protein-protein crosslinking are presented and the implications of such mechanisms for other long-lived proteins in other tissues are discussed in the context of age-related neurological diseases. A comprehensive understanding of LLP modifications will enhance our ability to develop new therapies for the delay, prevention or reversal of age-related diseases.

12.
Neurosci Lett ; : 134616, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31705923

RESUMO

INTRODUCTION: Synaptosomal associated proteins of 25 kDa (SNAP-25), as a member of stable soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex, is critical for membrane fusion and required for the release of neurotransmitters. The α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor is implicated in pathologic pain. This study aimed to investigate whether and how SNAP-25 regulated AMPA receptors in neuropathic pain. METHODS: Male Sprague-Dawley rats underwent L4 spinal nerve ligation (SNL) or the sham procedure. After assessing mechanical allodynia and thermal sensitivity, the ipsilateral portion of the L4-5 spinal cord was harvested. The expression level of SNAP-25 was analyzed by Western blot analysis and real-time quantitative polymerase chain reaction. SNAP-25 phosphorylation and AMPA receptor membrane trafficking levels were evaluated with Western blot analysis. An association between SNAP-25 and AMPA membrane trafficking was confirmed by SNAP-25 expression or phosphorylation inhibition. RESULTS: The SNL procedure induced and maintained mechanical allodynia and thermal hyperalgesia. SNL increased the expression and phosphorylation of SNAP-25 and the membrane trafficking of AMPA receptors in the spinal cord. SNAP-25 expression or phosphorylation inhibition alleviated neuropathic pain and downregulated membrane trafficking of AMPA receptors after SNL. GluA1-containing AMPA receptor inhibition relieved mechanical allodynia and thermal hyperalgesia after SNL. CONCLUSIONS: The upregulation of SNAP-25-dependent membrane trafficking of AMPA receptors via SNAP-25 phosphorylation at Ser187 contributed to SNL-induced neuropathic pain. Thus, the inhibition of SNAP-25 expression or phosphorylation might serve as a treatment for neuropathic pain. However, the mechanism of GluA1-containing AMPA receptor membrane trafficking mediated by SNAP-25 phosphorylation in neuropathic pain deserves further exploration.

13.
Eur J Med Chem ; : 111866, 2019 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-31734023

RESUMO

Introducing pyrimidine bases, the basic components of nucleic acid, to P2 ligands might enhance the potency of Human Immunodeficiency Virus-1 (HIV-1) protease inhibitors because of the carbonyl and amino groups promoting the formation of extensive hydrogen bonding interactions. In this work, we provide evidence that inhibitor 10e, with N-2-(2,4-Dioxo-3,4-dihydropyrimidin-1(2H)-yl) acetamide as the P2 ligand and a 4-methoxylphenylsulfonamide as the P2' ligand, displayed remarkable enzyme inhibitory and antiviral activity, with the IC50 2.53 nM in vitro and a promising inhibition ratio with 68% against wild-type HIV-1 in vivo, with low cytotoxicity. This inhibitor also exhibited appreciable antiviral activity against DRV-resistant HIV-1 variants, which was of great value for further study.

14.
Drug Deliv ; 26(1): 1125-1139, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31736389

RESUMO

Stability in systemic circulation, effective tumor accumulation, and the subsequent crucial subcellular targeting are significant elements that maximize the therapeutic efficacy of a drug. Accordingly, novel nanoparticles based on polysaccharides that simultaneously presented prolonged systemic circulation and mitochondrial-targeted drug release were synthesized. First, the mitochondrial-targeted polymer, 3,4-dihydroxyphenyl propionic acid-chitosan oligosaccharide-dithiodipropionic acid-berberine (DHPA-CDB), was synthesized, which was used to form self-assembled curcumin (Cur)-encapsulated cationic micelles (DHPA-CDB/Cur). Negatively charged oligomeric hyaluronic acid-3-carboxyphenylboronic acid (oHA-PBA), a ligand to sialic acid and CD44, was further added to the surface of the preformed DHPA-CDB/Cur core to shield the positive charges and to prolong blood persistence. oHA-PBA@DHPA-CDB/Cur formed a covalent polyplex of oHA-PBA and DHPA-CDB/Cur via the pH-responsive borate ester bond between PBA and DHPA. The mildly acidic tumor environment led to the degradation of borate ester bonds, thereby realizing the exposure of the cationic micelles and causing a charge reversal from -19.47 to +12.01 mV, to promote cell internalization and mitochondrial localization. Compared with micelles without the oHA-PBA modification, the prepared oHA-PBA@DHPA-CDB/Cur showed enhanced cytotoxicity to PANC-1 cells and greater cellular uptake via receptor-mediated endocytosis. oHA-PBA@DHPA-CDB/Cur was effectively targeted to the mitochondria, which triggered mitochondrial membrane depolarization. In mice xenografted with PANC-1 cells, compared with control mice, oHA-PBA@DHPA-CDB/Cur resulted in more effective tumor suppression and greater biosafety with preferential accumulation in the tumor tissue. Thus, the long-circulating oHA-PBA@DHPA-CDB/Cur, with mitochondrial targeting and tumor environment charge-reversal capabilities, was shown to be an excellent candidate for subcellular-specific drug delivery.

15.
Int J Cardiol ; 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31757645

RESUMO

BACKGROUND: Recurrent spontaneous coronary artery dissection (SCAD) is believed to be infrequent. Predictors of recurrent SCAD are poorly characterized. METHODS: We evaluated the incidence, clinical characteristics, and predictors of recurrent SCAD using data from the Nationwide Readmissions Database from January 1, 2010, to December 30, 2016. RESULTS: Among 1836 SCAD patients admitted with the primary diagnosis of SCAD (61.9% female, mean age 56.1 ±â€¯14.5, 72.9% <65 years of age), 495 patients (26.9%) had recurrent SCAD within 1 year (74.0% female, 74% <65 years of age). Multivariable analysis showed that female sex (OR 2.09; 95% CI 1.49-2.95; p < 0.001) was an independent predictor of recurrent SCAD within 1 year. CONCLUSIONS: Recurrent SCAD is frequent and should be considered in younger females with a history of SCAD. Further research is needed to investigate the mechanistic links between female sex and recurrent SCAD.

16.
Med Sci Monit ; 25: 8873-8890, 2019 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-31758680

RESUMO

BACKGROUND Breast cancer has a high mortality rate and is the most common cancer of women worldwide. Our gene co-expression network analysis identified the genes closely related to the pathological stage of breast cancer. MATERIAL AND METHODS We performed weighted gene co-expression network analysis (WGCNA) from the Gene Expression Omnibus (GEO) database, and performed pathway enrichment analysis on genes from significant modules. RESULTS A non-metastatic sample (374) of breast cancer from GSE102484 was used to construct the gene co-expression network. All 49 hub genes have been shown to be upregulated, and 19 of the 49 hub genes are significantly upregulated in breast cancer tissue. The roles of the genes CASC5, CKAP2L, FAM83D, KIF18B, KIF23, SKA1, GINS1, CDCA5, and MCM6 in breast cancer are unclear, so in order to better reveal the staging of breast cancer markers, it is necessary to study those hub genes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes indicated that 49 hub genes were enriched to sister chromatid cohesion, spindle midzone, microtubule motor activity, cell cycle, and something else. Additionally, there is an independent data set - GSE20685 - for module preservation analysis, survival analysis, and gene validation. CONCLUSIONS This study identified 49 hub genes that were associated with pathologic stage of breast cancer, 19 of which were significantly upregulated in breast cancer. Risk stratification, therapeutic decision making, and prognosis predication might be improved by our study results. This study provides new insights into biomarkers of breast cancer, which might influence the future direction of breast cancer research.

17.
BMC Surg ; 19(1): 161, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31690303

RESUMO

BACKGROUND: Wound-related complications are an inevitable issue faced by spinal surgeons. Negative pressure drainage remains the most commonly used method to prevent postoperative hematoma and related complications. This prospective, randomized, controlled study was conducted to evaluate the efficacy of compression therapy following posterior lumbar interbody fusion, with emphasis on pain, anemia, and inflammation. METHODS: Sixty consecutive patients who have undergone posterior lumbar interbody fusion in the age range 43-78 years, with an average age of 59 years, were selected and randomly assigned into two groups. Factors, such as drainage volume, visual analog scale (VAS) pain score for back pain, white blood cell (WBC) count, red blood cell (RBC) count, hemoglobin (Hb) levels, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) levels assessed on the 1st, 3rd, and 10th days postoperatively, were compared between the two groups. RESULTS: The average follow-up was 6 months, ranging from 3 to 11 months. Drainage volume, VAS score, and CRP levels on the 10th day after the surgery were found to be significantly lower in the treatment group than in the control group. RBC count and Hb levels on the 3rd and 10th postoperative days were observed to be significantly higher in the treatment group than in the control group (P < 0.05). During discharge, the wounds of the patients of the both groups had healed and neither showed any symptoms of infection, hematoma, or necrosis. CONCLUSION: Compression therapy relieves pain, alleviates anemia, and the inflammatory response following posterior lumbar interbody fusion. TRIAL REGISTRATION: ChiCTR1800015825 on chictr.org.cn, April 23, 2018, the trial registry is Chinese Clinical Trial Registry.

18.
Environ Pollut ; : 113419, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31706769

RESUMO

Ozone has become a major atmospheric pollutant in China as the pattern of urban energy usage has changed and the number of motor vehicles has grown rapidly. The Beijing-Tianjin-Hebei Urban Agglomeration, also known as the Jing-Jin-Ji Urban Agglomeration (hereafter, JJJUA), with a precarious balance between protecting the ecological environment and sustaining economic development, is challenged by high levels of ozone pollution. Based on ozone observation data from 13 cities in the JJJUA from 2014 to 2017, the spatio-temporal trends in the evolution of ozone pollution and its associated influencing factors were analyzed using Moran's I Index, hot-spot analysis, and Geodetector using ArcGIS and SPSS software. Five key results were obtained. 1) There was an increase in the annual average ozone concentration, for the period 2014-2017. Comparing the 13 prefecture-level cities, ozone pollution in Chengde and Hengshui decreased, while it worsened in the remaining 11 cities. 2) Ozone pollution was worse in spring and summer than in autumn and winter; the peak ozone pollution season was from May to September; the average ozone concentration on workdays was higher than that on non-workdays, showing a counter-weekend effect. 3) Annual average concentrations were high in the central and southern parts of the study region but low in the north. 4) Prominent positive spatial correlations were observed in ozone concentration, with the best correlations shown in summer and autumn; concentrations were high in Baoding and Xingtai but low in Beijing and Chengde. 5) Concentrations of PM10, NO2, CO, SO2, and PM2.5, as well as average wind speed, sunshine duration, evaporation, precipitation, and temperature, all had significant effects on ozone pollution, and interactions between these influencing factors increased it.

19.
Artigo em Inglês | MEDLINE | ID: mdl-31751799

RESUMO

Branched chain fatty acids (BCFA) and linear chain/normal odd chain fatty acids (n-OCFA) are major fatty acids in human skin lipids, especially sebaceous gland (SG) wax esters. Skin lipids contain variable amounts of monounsaturated BCFA and n-OCFA, in some reports exceeding over 20% of total fatty acids. Fatty acid desaturase 2 (FADS2) codes for a multifunctional enzyme that catalyzes Δ4-, Δ6- and Δ8-desaturation towards ten polyunsaturated fatty acids but only one saturate, palmitic acid, converting it to 16:1n-10; FADS2 is not active towards 14:0 or 18:0. Here we test the hypothesis that FADS2 also operates on BCFA and n-OCFA. MCF-7 cancer cells stably expressing FADS1 or FADS2 along with empty vector control cells were incubated with anteiso-15:0, iso-16:0, iso-17:0, anteiso-17:0, iso-18:0, or n-17:0. BCFA were Δ6-desaturated by FADS2 as follows: iso-16:0 → iso-6Z-16:1, iso-17:0 → iso-6Z-17:1, anteiso-17:0 → anteiso-6Z-17:1 and iso-18:0 → iso-6Z-18:1. anteiso-15:0 was not desaturated in either FADS1 or FADS2 cells. n-17:0 was converted to both n-6Z-17:1 by FADS2 Δ6-desaturation and n-9Z-17:1 by SCD Δ9-desaturation. We thus establish novel FADS2-coded enzymatic activity towards BCFA and n-OCFA, expanding the number of known FADS2 saturated fatty acid substrates from one to six. Because of the importance of FADS2 in human skin, our results imply that dysfunction in activity of sebaceous FADS2 may play a role in skin abnormalities associated with skin lipids.

20.
Nat Commun ; 10(1): 5248, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31748526

RESUMO

Polar metals are commonly defined as metals with polar structural distortions. Strict symmetry restrictions make them an extremely rare breed as the structural constraints favor insulating over metallic phase. Moreover, no polar metals are known to be magnetic. Here we report on the realization of a magnetic polar metal phase in a BaTiO3/SrRuO3/BaTiO3 heterostructure. Electron microscopy reveals polar lattice distortions in three-unit-cells thick SrRuO3 between BaTiO3 layers. Electrical transport and magnetization measurements reveal that this heterostructure possesses a metallic phase with high conductivity and ferromagnetic ordering with high saturation moment. The high conductivity in the SrRuO3 layer can be attributed to the effect of electrostatic carrier accumulation induced by the BaTiO3 layers. Density-functional-theory calculations provide insights into the origin of the observed properties of the thin SrRuO3 film. The present results pave a way to design materials with desired functionalities at oxide interfaces.

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