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1.
Environ Pollut ; 261: 114115, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-32045794

RESUMO

The air traffic growth at Shanghai Pudong International Airport (PVG) has attracted much concern over the potential impacts on local air quality and human health; however, the emission contributions due to aircraft activities, impact on air quality and health effects remain unclear. In this study, the ground operational data derived from the Aircraft Communication Addressing and Reporting System (ACARS) dataset are newly utilized to obtain the PVG-specific emission parameters of 10 distinct aircraft-engine combinations during the taxi-in and taxi-out phases of the landing and take-off (LTO) cycle. The resulting emission parameters, together with PVG-specific operational conditions, are applied to quantify the annual emissions in 2017 for main engines and auxiliary power units (APUs) at PVG, emission variations caused by mixing layer height, sensitivity of black carbon (BC) emissions to the estimation method and sensitivity of PM2.5 emissions to the fuel sulfur content (FSC). The results show noticeable discrepancies between the corrected fuel flows and NOx emission indices (EIs) and those certified by the International Civil Aviation Organization (ICAO). The annual emissions of hydrocarbons (HC), CO, NOx, NO, NO2, HONO, HNO3, NOy, SO2, SO42-, BC, organic carbon (OC) and PM2.5 with corrected emission parameters are 3.82 × 105 kg, 4.35 × 106 kg, 5.36 × 106 kg, 4.40 × 106 kg, 9.58 × 105 kg, 1.03 × 105 kg, 3.83 × 103 kg, 5.47 × 106 kg, 3.56 × 105 kg, 1.31 × 104 kg, 5.43 × 104 kg, 4.73 × 103 kg and 7.22 × 104 kg, respectively, while the application of the maximum height of the mixing layer contributes to emission increases as high as 16.9% (NOx). An alternative estimation of BC emissions leads to an increase of 50% compared with first-order approximation 3 (FOA3), while a reduction in PM2.5 emissions can be expected by minimizing the FSC.

2.
Biomed Pharmacother ; 125: 109845, 2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-32058211

RESUMO

Osteoarthritis (OA), a progressive joint disorder, is principally characterized by the degeneration and destruction of the articular cartilage. Ellagic acid (EA), a natural polyphenol found in berries and nuts has shown potent anti-inflammatory effects, however, its effects and underlying mechanisms on OA have seldom been systematically illuminated. In this study, we reported the anti-inflammatory effects of Ellagic acid (EA) in the progression of OA in both in vitro and in vivo experiments. in vitro study, IL-1ß-induced expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), Nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), prostaglandin E2 (PGE2), and interleukin-6 (IL-6) were inhibited by Ellagic acid (EA). Moreover, Ellagic acid (EA) down-regulated the IL-1ß-stimulated matrix metalloproteinase-13 (MMP-13) and thrombospondin motifs 5 (ADAMTS-5) while up-regulated the collagen of type II and aggrecan. Mechanistically, we revealed that Ellagic acid (EA) suppressed nuclear factor kappa B (NF-κB) signaling in IL-1ß -induced chondrocytes. And Ellagic acid (EA)-induced protectiveness in OA development was also shown by the DMM model. Taken together, our data indicate that Ellagic acid (EA) may serve as a potential drug for OA treatment.

3.
Gastrointest Endosc ; 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31981648

RESUMO

BACKGROUND AND AIMS: Compared with conventional endoscopy, magnetically controlled capsule gastroscopy (MCCG) can be further optimized in gastric examination time and complete visualization of upper gastrointestinal (UGI) mucosa. The second-generation MCCG (MCCG-2) was developed with higher image resolution and adaptive frame rate, and we aimed to evaluate its clinical availability for UGI examination in this study. METHODS: Consecutive patients undergoing MCCG examination between May to June 2019 were prospectively enrolled and randomized to swallow the first-generation MCCG (MCCG-1) or MCCG-2 in a 1:1 ratio. The main outcomes included visualization of the esophagus and duodenum, operation related parameters, image quality, maneuverability, detection of lesions, as well as safety evaluation. RESULTS: Eighty patients were enrolled. In MCCG-2 group, frames captured for esophageal mucosa and Z-line were 171.00 and 2.00, significantly increased from those in MCCG-1 group with 97.00 and 0.00 (P=0.002 and 0.028). The gastric examination time was shortened from 7.78±0.97 min to 5.27±0.74 min (P<0.001), with the total running time of capsule extended from 702.83 min to 1001.99 min (P<0.001). MCCG-2 also greatly improved the image quality (P<0.001) and maneuverability (P<0.01). No statistical difference existed in the detection of lesions between the 2 groups, and no adverse events occurred. CONCLUSIONS: MCCG-2 showed better performance in mucosal visualization, examination duration and maneuverability, making better diagnosis of UGI diseases a possibility.

4.
BMJ Open ; 10(1): e028593, 2020 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-31932385

RESUMO

OBJECTIVE: The aims of this study were to describe distributions of the prevalence of osteopenia and osteoporosis and identify the potential risk factors by gender in a Chinese rural population. DESIGN: A cross-sectional survey. SETTING AND PARTICIPANTS: A total of 8475 participants (18-79 years) were obtained from the Henan Rural Cohort Study. Bone mineral density (BMD) of the calcaneus for each individual was measured by ultrasonic bone density apparatus. Logistic regression models were used to evaluate associations of potential risk factors with prevalence of osteopenia and osteoporosis. Furthermore, a meta-analysis of prevalence of osteoporosis which included eight studies was conducted to confirm this study results. RESULTS: The mean of BMD were 0.42 and 0.32 g/cm2 for men with osteopenia and osteoporosis (p<0.001), as well as 0.40 and 0.30 g/cm2 (p<0.001) for women with osteopenia and osteoporosis, respectively. The overall age-standardised prevalence of osteopenia and osteoporosis were 42.09% and 11.76% in all participants. The age-standardised prevalence of osteopenia in men (45.98%) was significantly higher than that in women (39.73%), whereas the age-standardised prevalence of osteoporosis in men (7.82%) was lower than that in women (14.38%). Meta-analysis results displayed pooled prevalence of osteoporosis of 18.0% (10.1%-25.8%) in total sample, 7.7% (5.7%-9.7%) in men and 22.4% (17.1%-27.6%) in women. Multivariable logistic regression models showed that ageing, women, low education level or income, drinking or underweight was related to increased risk for osteopenia or osteoporosis. CONCLUSIONS: About one-sixth of the participants suffered osteoporosis in rural China, and the prevalence in women was higher than men. Although the results were lower than that of meta-analysis, osteoporosis still accounts for huge burden of disease in rural population due to limited medical service and lack of health risk awareness rather than urban area. TRIAL REGISTRATION NUMBER: Chinese Clinical Trial Registry (ChiCTR-OOC-15006699; Pre-results).

5.
Aging (Albany NY) ; 12(2): 1867-1887, 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-31986487

RESUMO

OBJECTIVES: Breast cancer has been the second most prevalent and fatal malignancy due to its frequent metastasis to other organs. We aim to study the effects of a key miRNA-mRNA signaling in breast cancer. RESULTS: CNN1 was identified as the key gene in breast cancer by the bioinformatics analysis, and the downregulation of CNN1 in breast cancer tissues and cell lines was observed. Upregulating CNN1 inhibited cell survival, migration, invasion, and adhesion, but enhanced cell apoptosis. miR-106b-5p not only bound to CNN1 mRNA 3'UTR, but also promoted lung metastasis in vivo. Besides, the miR-106b-5p mimic enhanced breast cancer canceration by targeting CNN1 and activating Rho/ROCK1 signaling pathway. CONCLUSION: Overall, our results proved that miR-106b-5p promoted the metastasis of breast cancer by suppressing CNN1 and activating Rho/ROCK1 pathway. METHODS: Bioinformatics analysis was performed to select the key gene in breast cancer. The overexpression and knockdown of Calponin 1 (CNN1) in breast cancer cell lines were performed to conduct cell viability, migrating, invasion, proliferation, adhesion, and apoptosis experiments. To identify the role of miR-106b-5p and Rho/ROCK1 in CNN1-induced breast cancer, a dual-luciferase assay, tumor lung metastasis assay, transcript half-life assay, and Rho/ROCK1 inhibition assay were performed.

6.
Nat Commun ; 11(1): 170, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31924790

RESUMO

Reduced-dimensional perovskites are attractive light-emitting materials due to their efficient luminescence, color purity, tunable bandgap, and structural diversity. A major limitation in perovskite light-emitting diodes is their limited operational stability. Here we demonstrate that rapid photodegradation arises from edge-initiated photooxidation, wherein oxidative attack is powered by photogenerated and electrically-injected carriers that diffuse to the nanoplatelet edges and produce superoxide. We report an edge-stabilization strategy wherein phosphine oxides passivate unsaturated lead sites during perovskite crystallization. With this approach, we synthesize reduced-dimensional perovskites that exhibit 97 ± 3% photoluminescence quantum yields and stabilities that exceed 300 h upon continuous illumination in an air ambient. We achieve green-emitting devices with a peak external quantum efficiency (EQE) of 14% at 1000 cd m-2; their maximum luminance is 4.5 × 104 cd m-2 (corresponding to an EQE of 5%); and, at 4000 cd m-2, they achieve an operational half-lifetime of 3.5 h.

7.
Eur J Drug Metab Pharmacokinet ; 45(1): 51-69, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31602595

RESUMO

BACKGROUND AND OBJECTIVES: Methyl 3,4-dihydroxybenzoate (MDHB) has the potential to prevent neurodegenerative diseases (NDDs). The present work investigated its excretion, metabolism, and cytochrome P450-based drug-drug interactions (DDIs). METHODS: After intragastric administration of MDHB, the parent drug was assayed in the urine and faeces of mice. Metabolites of MDHB in the urine, faeces, brain, plasma and liver were detected by liquid chromatography-hybrid quadrupole time-of-flight mass spectrometry (LC-QTOF/MS). A cocktail approach was used to evaluate the inhibition of cytochrome P450 isoforms by MDHB. RESULTS: The cumulative excretion permille of MDHB in the urine and faeces were found to be 0.67 ± 0.31 and 0.49 ± 0.44‰, respectively. A total of 96 metabolites of MDHB were identified, and all IC50 (half-maximal inhibitory concentration) values of MDHB towards cytochrome P450 isoforms were > 100 µM. CONCLUSIONS: The results suggest that MDHB has a low parent drug cumulative excretion percentage and that MDHB has multiple metabolites and is mainly metabolized through the loss of -CH2 and -CO2, the loss of -CH2O, ester bond hydrolysis, the loss of -O and -CO2, isomerization, methylation, sulfate conjugation, the loss of -CH2O and -O and glycine conjugation, glycine conjugation, the loss of two -O groups and alanine conjugation, the loss of -CH2O and -O and glucose conjugation, glucuronidation, glucose conjugation, etc., in vivo. Finally, MDHB has a low probability of cytochrome P450-based DDIs.

8.
Cytokine ; 127: 154920, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31786503

RESUMO

Stanford type A Aortic dissection (TAAD) is a deadly cardiovascular disease but the relationship between inflammatory cytokines and disease pathogenesis is still unclear. Observation of the changes of different chemokines may help to explore the etiology of TAAD much further. Clinical data was collected from TAAD patients (TAAD group) and healthy controls (HC group) in our institute between October 2013 and December 2014. Blood sample was harvested from each subject of two groups. The expression levels of eighty chemokines were examined by protein array technology. Then we tested the expressions of macrophage inflammatory protein 1ß (MIP-1ß), epithelial neutrophil activating peptide 78 (ENA-78), interleukin 16 (IL-16), interferon inducible protein 10 (IP-10), and FMS-like tyrosine kinase 3 (Flt-3) ligand by using luminex technology. Osteopontin (OPN) and monocyte chemotaxis protein (MCP) levels were analyzed by ELISA kits. The mean age of TAAD group is 49.9 ±â€¯11.2 and 48.7 ±â€¯9.9 in HC group, respectively. 76.0% of TAAD patients and 72.0% of healthy controls were male. MIP-1ß and ENA-78 expression in TAAD group were significantly lower than that in HC group, while significant increasing IL-16 level was found. Plasma levels of OPN in TAAD group increased remarkably compared with HC group, but MCP-1 and MCP-2 expression significantly decreased. No correlation was shown between serum CRP levels and plasma level of these cytokines by using Spearman analysis. ROC analysis showed that OPN could be indicators for TAAD diagnosis with sensitivity of 0.92 and specificity of 0.99. Our results provide a reasonable way to focus on the chemokines in understanding the pathogenesis of human TAAD.

9.
Br J Cancer ; 122(2): 209-220, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31819189

RESUMO

BACKGROUND: Mitochondrial dynamics plays an important role in tumour progression. However, how these dynamics integrate tumour metabolism in hepatocellular carcinoma (HCC) metastasis is still unclear. METHODS: The mitochondrial fusion protein mitofusin-1 (MFN1) expression and its prognostic value are detected in HCC. The effects and underlying mechanisms of MFN1 on HCC metastasis and metabolic reprogramming are analysed both in vitro and in vivo. RESULTS: Mitochondrial dynamics, represented by constant fission and fusion, are found to be associated with HCC metastasis. High metastatic HCC displays excessive mitochondrial fission. Among genes involved in mitochondrial dynamics, MFN1 is identified as a leading downregulated candidate that is closely associated with HCC metastasis and poor prognosis. While promoting mitochondrial fusion, MFN1 inhibits cell proliferation, invasion and migration capacity both in vitro and in vivo. Mechanistically, disruption of mitochondrial dynamics by depletion of MFN1 triggers the epithelial-to-mesenchymal transition (EMT) of HCC. Moreover, MFN1 modulates HCC metastasis by metabolic shift from aerobic glycolysis to oxidative phosphorylation. Treatment with glycolytic inhibitor 2-Deoxy-D-glucose (2-DG) significantly suppresses the effects induced by depletion of MFN1. CONCLUSIONS: Our results reveal a critical involvement of mitochondrial dynamics in HCC metastasis via modulating glucose metabolic reprogramming. MFN1 may serve as a novel potential therapeutic target for HCC.

10.
Front Aging Neurosci ; 11: 279, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31803043

RESUMO

Although lipopolysaccharides (LPS) have been used to establish animal models of memory loss akin to what is observed in Alzheimer's disease (AD), the exact mechanisms involved have not been substantiated. In this study, we established an animal model of learning and memory impairment induced by LPS and explored the biological processes and pathways involved. Mice were continuously intraperitoneally injected with LPS for 7 days. Learning- and memory-related behavioral performance and the pathological processes involved were assessed using the Morris water maze test and immunostaining, respectively. We detected comprehensive expression of C1q, C3, microglia, and their regulatory cytokines in the hippocampus. After 7 days of LPS administration, we were able to observe LPS-induced learning and memory impairment in the mice, which was attributed to neural impairment and synapse loss in the hippocampus. We elucidated that the immune system was activated, with the classical complement pathway and microglial phagocytosis being involved in the synapse loss. This study demonstrates that an LPS-injected mouse can serve as an early memory impairment model for studies on anti-AD drugs.

11.
Onco Targets Ther ; 12: 9029-9040, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31806991

RESUMO

Purpose: Receptor-interacting protein kinase 1 (RIPK1) is an important upstream regulator of multiple cell signaling pathways including inflammatory signals. RIPK1 is reported to be closely associated with the prognostic implications of cancer, especially epithelial tumors. But its role in proliferation and lymphangiogenesis in cholangiocarcinoma (CCA) remains unclear and requires further investigation. Patients and methods: Expression of RIPK1 in human CCA tissues and CCA cell lines (QBC939, HUH28 and CCPL-1) was measured using qPCR, immunoblotting and immunohistochemistry. Silencing of RIPK1 was achieved by transduction of CCA cells via lentiviral plasmids (LV3-H1/GFP&Puro) encapsulating RIPK1 shRNA (LV-shRIPK1) or negative control shRNA (LV-shNC), and puromycin was used to select stable colonies. Proliferation and lymphangiogenesis were assessed in vitro by CCK-8 and matrigel-based tube formation assays, respectively. Activity of the activation protein-1 (AP-1) was evaluated by double-luciferase reporter gene assay. Protein expression of JNK, P38MAPK, ERK1/2, AP-1, P-AP-1, E-cadherin, N-cadherin and vascular endothelial growth factor-C (VEGF-C) was measured by immunoblotting or ELISA. An orthotopic CCA model in null mice was generated by transplanting QBC939 LV-shRIPK1, LV-shNC and control cells to further evaluate the role of RIPK1 on lymphangiogenesis in vivo. Immunohistochemistry was utilized to evaluate the expression of RIPK1 and VEGF-C, and tumor lymphatic vessels in the CCA model mice. Results: Upregulated expression of RIPK1 in CCA tissues was closely related to tumor size, lymph node metastasis and poor prognosis. RIPK1 promoted proliferation and lymphangiogenesis in CCA cells, and regulated the activation of JNK and P38MAPK-mediated AP-1/VEGF-C pathway. Finally, in vivo animal experiments in the orthotopic CCA mouse model further confirmed the function of RIPK1 in lymphangiogenesis. Conclusion: This is the first report demonstrating the role of RIPK1 in proliferation and lymphangiogenesis through the MAPK (JNK and P38MAPK)- AP-1 pathway in CCA.

12.
BMJ Open ; 9(12): e025803, 2019 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-31874864

RESUMO

OBJECTIVES: To investigate the treatment effects of endoscopic submucosal dissection (ESD) versus endoscopic mucosal resection (EMR) for early gastric cancer (EGC). DESIGN: Meta-analysis. METHODS: We systematically searched three electronic databases, including PubMed, EmBase and the Cochrane library for studies published with inception to January 2018. The eligible studies should be evaluated for the efficacy and safety of ESD versus EMR for patients with EGC. The summary ORs and standard mean differences (SMDs) with 95% CIs were employed as effect estimates. Sensitivity analyses were conducted to evaluate the impact of single study on overall analysis. Subgroup analyses were performed for investigated outcomes to evaluate the treatment effects of ESD versus EMR for patients with EGC with specific subsets. RESULTS: Eighteen studies, with a total of 6723 patients with EGC, were included in final analysis. The summary ORs indicated that patients with EGC who received ESD were associated with an increased incidence of en bloc resection (OR: 9.00; 95% CI: 6.66 to 12.17; p<0.001), complete resection (OR: 8.43; 95% CI: 5.04 to 14.09; p<0.001) and curative resection (OR: 2.92; 95% CI: 1.85 to 4.61; p<0.001) when compared with EMR. Furthermore, ESD was associated with lower risk of local recurrence (OR: 0.18; 95% CI: 0.09 to 0.34; p<0.001). In addition, there was no significant difference between ESD and EMR for the risk of bleeding (OR: 1.26; 95% CI: 0.88 to 1.80; p=0.203). Though, ESD was correlated with greater risk of perforation (OR: 2.55; 95% CI: 1.48 to 4.39; p=0.001), and longer operation time (SMD: 1.12; 95% CI: 0.13 to 2.10; p=0.026) as compared with EMR. Additionally, several different features observed in included studies and patients could bias the effectiveness of ESD versus EMR in patients with EGC. CONCLUSIONS: ESD is superior than EMR for en bloc resection, complete resection, curative resection and local recurrence, while it increased perforation risk and longer operation time.

13.
J Nat Prod ; 82(11): 3111-3120, 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31686503

RESUMO

Buxaustroines A-N (1-14), a series of triterpenoidal alkaloids featuring a novel 17(13→18)abeo motif, were obtained from the extract of Buxus austro-yunnanensis. Their structures were assigned based on NMR data analysis and X-ray diffraction crystallography. A putative biosynthetic pathway for one of the alkaloids from a co-isolate 15 is proposed. In the assessment of their bioactivities, some of the compounds displayed protective effects against doxorubicin-induced injury of myocardial cells. Preliminary structure-activity relationship studies of 1-14, which are based on the same skeleton, were conducted.

14.
Virol J ; 16(1): 129, 2019 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-31699105

RESUMO

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging hemorrhagic fever that was first described in China in 2011. We report a patient who died of Severe fever with thrombocytopenia syndrome virus (SFTSV) infection, with a rapidly progressive central nervous system (CNS) disturbance, in Dongyang, Zhejiang Province, China, in 2017. CASE PRESENTATION: A 64-year-old man was admitted to hospital after 4 days of fever. SFTSV was detected 1 day after the patient was admitted to hospital. The patient presented with CNS disturbance and died 4 days after admission. Detailed clinical and epidemiological investigations and laboratory tests were conducted. Reduced platelet, white blood cell, lymphocyte, and neutrophil counts, elevated lactate dehydrogenase, creatine kinase, aspartate aminotransferaseand alanine aminotransferase concentrations, and an increased activated partial thromboplastin time were observed. In a phylogenetic analysis, the isolate clustered close to a strain derived from South Korea. CONCLUSIONS: This is the first case of SFTSV infection with CNS disturbance in Dongyang, Zhejiang Province, China. The surveillance of suspected cases of SFTS is important in SFTSV endemic regions.

15.
Hemoglobin ; 43(4-5): 241-244, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31690131

RESUMO

Although mutations causing α-thalassemia (α-thal) are mainly larger deletions involving one or both of the duplicated α-globin genes, point mutations are not rare. We have identified a novel mutation of the translation initiation codon of the α2-globin gene with DNA sequencing and allele-specific multiplex ligation-dependent probe amplification (MLPA) in a Chinese family. RNA analysis was performed with reverse transcription-MLPA (RT-MLPA). A novel mutation at the translation initiation codon of the α2-globin gene (HBA2: c.3G>C) was identified. The proband and his father, who were both carriers of this mutation, had a hematological phenotype of mild α+-thalassemia (α+-thal) trait with low-normal limit of mean corpuscular volume (MCV) and normal Hb A2. RNA analysis showed markedly decreased levels of α-globin mRNA and the presence of a small amount of mutant mRNA. The HBA2: c.3G>C mutation most likely caused α-thal by lowering levels of wild α-globin chain. Our study increases the mutation spectrum of α-thal.

16.
Medicine (Baltimore) ; 98(48): e17984, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31770208

RESUMO

Pediatric patients suffer from chronic pancreatitis (CP), especially those with diabetes mellitus (DM). This study aimed to identify the incidence of and risk factors for DM in pediatric CP.CP patients admitted to our center from January 2000 to December 2013 were assigned to the pediatric (<18 years old) and adult group according to their age at onset of CP. Cumulative rates of DM and risk factors for both groups were calculated and identified.The median follow-up duration for the whole cohort was 7.6 years. In these 2153 patients, 13.5% of them were pediatrics. The mean age at the onset and the diagnosis of CP in pediatrics were 11.622 and 19.727, respectively. DM was detected in 13.1% patients and 31.0% patients in the pediatric group and adult group, respectively. Age at the onset of CP, smoking history, body mass index (BMI), and etiology of CP were identified risk factors for DM in pediatrics.DM was detected in 13.1% pediatric patients. Age at the onset of CP, smoking history, BMI, and etiology of CP were identified risk factors for the development of DM in pediatric CP patients. The high-risk populations were suggested to be monitored frequently. They could also benefit from a lifestyle modification.


Assuntos
Diabetes Mellitus/epidemiologia , Diabetes Mellitus/etiologia , Pancreatite Crônica/complicações , Adolescente , Criança , Bases de Dados Factuais , Feminino , Humanos , Incidência , Masculino , Estudos Retrospectivos , Fatores de Risco , Adulto Jovem
17.
Light Sci Appl ; 8: 94, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31645937

RESUMO

Optical wireless communication (OWC) using the ultra-broad spectrum of the visible-to-ultraviolet (UV) wavelength region remains a vital field of research for mitigating the saturated bandwidth of radio-frequency (RF) communication. However, the lack of an efficient UV photodetection methodology hinders the development of UV-based communication. The key technological impediment is related to the low UV-photon absorption in existing silicon photodetectors, which offer low-cost and mature platforms. To address this technology gap, we report a hybrid Si-based photodetection scheme by incorporating CsPbBr3 perovskite nanocrystals (NCs) with a high photoluminescence quantum yield (PLQY) and a fast photoluminescence (PL) decay time as a UV-to-visible colour-converting layer for high-speed solar-blind UV communication. The facile formation of drop-cast CsPbBr3 perovskite NCs leads to a high PLQY of up to ~73% and strong absorption in the UV region. With the addition of the NC layer, a nearly threefold improvement in the responsivity and an increase of ~25% in the external quantum efficiency (EQE) of the solar-blind region compared to a commercial silicon-based photodetector were observed. Moreover, time-resolved photoluminescence measurements demonstrated a decay time of 4.5 ns under a 372-nm UV excitation source, thus elucidating the potential of this layer as a fast colour-converting layer. A high data rate of up to 34 Mbps in solar-blind communication was achieved using the hybrid CsPbBr3-silicon photodetection scheme in conjunction with a 278-nm UVC light-emitting diode (LED). These findings demonstrate the feasibility of an integrated high-speed photoreceiver design of a composition-tuneable perovskite-based phosphor and a low-cost silicon-based photodetector for UV communication.

18.
Cancer Genomics Proteomics ; 16(6): 465-479, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31659101

RESUMO

BACKGROUND: Hyperactivity of the mechanistic target of rapamycin complex 1 (mTORC1) is implicated in a variety of diseases such as cancer and diabetes. Treatment may benefit from effective mTORC1 inhibition, which can be achieved by preventing arginine from disrupting the cytosolic arginine sensor for mTORC1 subunit 1 (CASTOR1)-GTPase-activating proteins toward RAGS subcomplex 2 (GATOR2) complex through binding with CASTOR1. An attractive idea is to determine analogues of arginine that are as competent as arginine in binding with CASTOR1, but without disrupting the CASTOR1-GATOR2 interaction. MATERIALS AND METHODS: Molecular dynamics simulations were performed for binding of arginine analogues with CASTOR1 and binding free energy, hydrogen bond formation, and root mean squared deviation and root mean square fluctuation kinetics were then calculated. RESULTS: The binding free energy calculations revealed that Nα-acetyl-arginine, citrulline, and norarginine have sufficient binding affinity with CASTOR1 to compete with arginine. The hydrogen bond analysis revealed that norarginine, Nα-acetyl-arginine and D-arginine have proficient H-bonds that can facilitate their entering the narrow binding pocket. CONCLUSION: Norarginine and Nα-acetyl-arginine are the top drug candidates for mTORC1 inhibition, with Nα-acetyl-arginine being the best choice.

19.
Macromol Rapid Commun ; 40(22): e1900435, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31596528

RESUMO

Sequence-controlled polymerization is the forefront of polymer chemistry. Herein, the feasibility of sequence regulation by using organocatalyzed ring-opening polymerization (ROP) is demonstrated. In particular, ring expansion strategy is employed to synthesize pre-organized monomers 1 and 2. ROP is conducted by using 1,5,7-triazabicyclo[4.4.0]dec-5-ene and benzyl alcohol as the catalyst and initiator, respectively. Poly(ester amide)s (PEAs) P1-P3 comprising glycolic acid, lactic acid, and 7-aminoheptanoic acid units are obtained in high molecular weights and good yields. NMR and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry results verify the microstructural integrity of P1 and P2. Differential scanning calorimetry results show that PEA without methyl branches is crystalline. Moreover, thermal stability, surface wettability, and degradation profiles of P1-P3 are also investigated.

20.
Heart Surg Forum ; 22(5): E366-E371, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31596713

RESUMO

OBJECTIVE: To investigate single center's clinical experiences of aortic valve surgery for aortitis patients. METHODS: From January 2010 to December 2018, 15 patients with aortitis disease were treated in our center. Among them, there were 7 males and 8 females with an average age of 48.5 ± 13.9 (29-76) years. Six patients were diagnosed as giant cell arteritis, 2 as Takayasu arteritis (Arteritis Group, N = 8) and 7 as Behcet's disease (BD Group, N = 7). Aortic valve surgery includes valvuloplasty, valve replacement, and root replacement (Bentall procedure). RESULTS: There were 15 cases with 19 operations, 8 cases in the Arteritis Group received 8 operations while 7 cases in the BD Group received 11 operations, including 4 redo operations. Preoperative patients' aortic valve regurgitation degree, diameter of ascending aorta and left ventricular ejection fraction were similar between the two groups. The type of aortic valve surgery also was no different. Cardiopulmonary bypass time of the BD Group seemed longer than the Arteritis Group but no different, the same as clamp time. Mechanical ventilation time is longer in the BD Group. The morbidity and mortality were similar, but the BD Group had significantly higher incidence of redo operations because of postoperative paravalvular leak or valve insufficiency (Arteritis Group versus BD Group, 0% versus 57.1%, P = .026). CONCLUSIONS: Clinical diagnosis and management of aortic valve patients with arteritis require comprehensive considerations. For aortitis patients with aortic valve surgery, special surgical techniques can be used to reduce the risk of prosthetic valve detachment.


Assuntos
Valva Aórtica/cirurgia , Aortite/cirurgia , Arterite de Células Gigantes/cirurgia , Implante de Prótese de Valva Cardíaca , Adulto , Idoso , Insuficiência da Valva Aórtica/cirurgia , Síndrome de Behçet/cirurgia , Ponte Cardiopulmonar , Feminino , Implante de Prótese de Valva Cardíaca/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Reoperação/estatística & dados numéricos , Arterite de Takayasu/cirurgia
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