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1.
Cell Oncol (Dordr) ; 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32006253

RESUMO

PURPOSE: FAM83D has been proposed to act as an oncoprotein in several types of human cancer. Its role and mode of action in human non-small cell lung cancer (NSCLC) metastasis and its impact on chemotherapy are as yet, however, poorly understood. METHODS: FAM83D expression was measured in NSCLC cells and normal lung epithelial cells, as well as in primary NSCLC tissues and corresponding adjacent non-cancerous tissues, using qRT-PCR, Western blotting and immunohistochemistry. FAM83D was stably overexpressed in BEAS2B cells or silenced in A549 and H1299 cells using retroviral or lentiviral vectors. The growth capacity of NSCLC cells was evaluated using MTT and colony formation assays. Epithelial-mesenchymal transition (EMT) was assessed using Western blotting and immunofluorescence. NSCLC cell invasive capacities were assessed using scratch wound healing and Boyden chamber assays. NSCLC cell viability in response to cisplatin treatment was assessed using MTT assays in vitro and a xenograft model in vivo. RESULTS: We found that FAM83D expression levels were significantly elevated in NSCLC cells and tissues, and positively correlated with tumor progression and a poor prognosis. Exogenous FAM83D overexpression promoted, while FAM83D silencing inhibited NSCLC cell proliferation, EMT and invasion. FAM83D silencing also reduced cisplatin resistance. Concordantly, we found that NSCLC patients with a low FAM83D expression benefited most from chemotherapy. Mechanistically, we found that FAM83D activated the protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway. Pharmacological treatment with either AKT or mTOR inhibitors reverted FAM83D-induced tumorigenic phenotypes. CONCLUSIONS: Our results suggest a role of FAM83D in NSCLC development. In addition, our results indicate that NSCLC patients exhibiting FAM83D overexpression are likely to benefit from AKT and/or mTOR inhibitor treatment.

2.
mSphere ; 5(1)2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31915218

RESUMO

The contribution of human gastrointestinal (GI) microbiota and metabolites to host health has recently become much clearer. However, many confounding factors can influence the accuracy of gut microbiome and metabolome studies, resulting in inconsistencies in published results. In this study, we systematically investigated the effects of fecal sampling regions and storage and retrieval conditions on gut microbiome and metabolite profiles from three healthy children. Our analysis indicated that compared to homogenized and snap-frozen samples (standard control [SC]), different sampling regions did not affect microbial community alpha diversity, while a total of 22 of 176 identified metabolites varied significantly across different sampling regions. In contrast, storage conditions significantly influenced the microbiome and metabolome. Short-term room temperature storage had a minimal effect on the microbiome and metabolome profiles. Sample storage in RNALater showed a significant level of variation in both microbiome and metabolome profiles, independent of the storage or retrieval conditions. The effect of RNALater on the metabolome was stronger than the effect on the microbiome, and individual variability between study participants outweighed the effect of RNALater on the microbiome. We conclude that homogenizing stool samples was critical for metabolomic analysis but not necessary for microbiome analysis. Short-term room temperature storage had a minimal effect on the microbiome and metabolome profiles and is recommended for short-term fecal sample storage. In addition, our study indicates that the use of RNALater as a storage medium of stool samples for microbial and metabolomic analyses is not recommended.IMPORTANCE The gastrointestinal microbiome and metabolome can provide a new angle to understand the development of health and disease. Stool samples are most frequently used for large-scale cohort studies. Standardized procedures for stool sample handling and storage can be a determining factor for performing microbiome or metabolome studies. In this study, we focused on the effects of stool sampling regions and stool sample storage conditions on variations in the gut microbiome composition and metabolome profile.

3.
FASEB J ; 2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31950551

RESUMO

Telomerase plays a pivotal role in tumorigenesis by maintaining telomere homeostasis, a hallmark of cancer. However, the mechanisms by which telomerase is reactivated or upregulated during tumorigenesis remain incompletely understood. Here, we report that the Hippo pathway effector Yes-associated protein (YAP) regulates the expression of human telomerase reverse transcriptase (hTERT). Ectopic expression or physiological activation of YAP increases hTERT expression, whereas knockdown of YAP decreases the expression of hTERT. YAP binds to the hTERT promoter through interaction with the TEA domain family transcription factors and activates hTERT transcription. Furthermore, sustained YAP hyperactivation promotes telomerase activity and extends telomere length, with increased hTERT expression. In addition, we show that hTERT expression is positively correlated with YAP activation in human liver cancer tissues. Together, our results demonstrate that YAP promotes hTERT expression, which could contribute to tumor progression.

4.
Gut Microbes ; : 1-13, 2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31944159

RESUMO

Hirschsprung disease (HSCR) is a birth defect with an approximate incidence of 1/5,000 live births, and up to one-third of HSCR patients develop Hirschsprung-associated enterocolitis (HAEC), the leading cause of HSCR-related death. Very little is known about the pathogenesis, prevention, and early diagnosis of HAEC. Here, we used a prospective study to investigate the enteric microbiome composition at the time of surgery as a predictor for developing postoperative HAEC. We identified a microbiome signature containing 21 operational taxonomic units (OTUs) that can potentially predict postoperative HAEC with ~85% accuracy. Furthermore, we identified exclusive breastfeeding as a novel protective factor for total HAEC (i.e., preoperative and postoperative HAEC combined). In addition, we discovered that breastfeeding was associated with a lowered risk for HAEC potentially mediated by modulating the gut microbiome composition characterized by a lower abundance of Gram-negative bacteria and lower LPS concentrations. In conclusion, modulating the gut microbiome by encouraging breastfeeding might prevent HAEC progression in HSCR patients.

5.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 27(6): 1799-1805, 2019 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-31839041

RESUMO

OBJECTIVE: To analyze the related factors affecting the nosopoiesis of childhood acute leukemia from the perspective of indoor environmental exposure, behavior and lifestyle. METHODS: The clinical data of 64 children with acute leukemia were retrospectively analyzed, and 50 healthy children were selected as the control group during the same period. The basic data of children, indoor environment, behavior and lifestyle of parents in 2 groups were recorded. Univariate and multivariate logistic regression analysis were used to analyze the related factors affecting the incidence of childhood acute leukemia, and the OR (95%CI) value was calculated. RESULTS: The unvariate analysis showed that the daily wine-drinking rate of father and pesticide use rate in acute leukemia group were significantly higher than those in control group (P<0.05). Multivariate Logistic regression analysis showed that indoor ventilation during summer sleep of children (OR=0.35, 95%CI: 0.14-0.88) and contact with other children before 3 years old (OR=0.34, 95%CI: 0.18-0.65) were protective factors for provention of childhood acute leukemia (P<0.05). Mothers had a history of exposure to chemical substances (OR=3.68, 95%CI: 1.64-8.27), and children had a history of exposure to chemical substances (OR=3.84, 95%CI: 1.64-9.01), family had internal decoration history after child birth (OR = 1.38, 95%CI: 1.05-1.81) and family uses of pesticides (OR=2.17, 95%CI: 1.08-4.36), all these factors were independent risk factors for acute leukemia (P<0.05). CONCLUSION: Indoor environmental exposure, behavior and lifestyle of children and parents may be closely related with the nosopoiesis of childhood acute leukemia.


Assuntos
Leucemia Mieloide Aguda , Estudos de Casos e Controles , Criança , Pré-Escolar , Exposição Ambiental , Humanos , Estudos Retrospectivos , Fatores de Risco
6.
Cancer Immunol Res ; 2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31831632

RESUMO

Because the incidence of breast cancer increases decades after ionizing radiation exposure, aging has been implicated in the evolution of the tumor microenvironment and tumor progression. Here, we investigated radiation-induced carcinogenesis using a model in which the mammary glands of 10-month-old BALB/c mice were transplanted with Trp53-null mammary tissue 3 days after exposure to low doses of sparsely ionizing γ-radiation or densely ionizing particle radiation. Mammary transplants in aged, irradiated hosts gave rise to significantly more tumors that grew more rapidly than those in sham-irradiated mice, with the most pronounced effects seen in mice irradiated with densely ionizing particle radiation. Tumor transcriptomes identified a characteristic immune signature of these aggressive cancers. Consistent with this, fast-growing tumors exhibited an immunosuppressive tumor microenvironment with few infiltrating lymphocytes, abundant immunosuppressive myeloid cells, and high COX-2 and TGFß. Only irradiated hosts gave rise to tumors lacking cytotoxic CD8+ lymphocytes (defined here as immune desert), which also occurred in younger irradiated hosts. These data suggest that host irradiation may promote immunosuppression. To test this, young chimera mice were fed chow containing a honeybee-derived compound with anti-inflammatory and immunomodulatory properties, caffeic acid phenethyl ester (CAPE). CAPE prevented the detrimental effects of host irradiation on tumor growth rate, immune signature, and immunosuppression. These data indicated that low-dose radiation, particularly densely ionizing exposure of aged mice, promoted more aggressive cancers by suppressing antitumor immunity. Dietary intervention with a nontoxic immunomodulatory agent could prevent systemic effects of radiation that fuel carcinogenesis, supporting the potential of this strategy for cancer prevention.

7.
Artigo em Inglês | MEDLINE | ID: mdl-31858358

RESUMO

Allergy to house dust mites (HDMs) can cause allergic rhinitis, allergic asthma and allergic skin disorders, which is becoming an enormous worldwide health and economic burden. To explore the relationship between air pollution and HDMs sensitization in children, this study used immunoblotting to determine the concentration of HDM serum-specific IgE (sIgE) in children with allergic diseases in Hangzhou. HDM sIgE was used to reflect the sensitization of children with HDMs. Using the meteorological and atmospheric pollutant data for Hangzhou, a distributed lag nonlinear model was founded to evaluate the effect of atmospheric pollutants on HDMs sensitization. Particulate matter (PM) 2.5 and PM10 were the main air pollutants in Hangzhou. The positive rate of HDM sIgE in children's serum increased with increasing PM2.5 and PM10 concentrations, and this effect was most obvious on the seventh and tenth days after increased PM2.5 and PM10 concentrations, respectively. In addition, there was a significant positive correlation between the concentration of HDM sIgE and the total serum IgE concentration. The rate of sensitization to HDMs rose dramatically in the first 3 years after birth. In addition, the period between June and November had the largest number of HDM sIgE-positive patients. Studies have shown that PM2.5 and PM10 are important factors in HDM sensitization, which presented obvious dose effects and lag effects. Children under the age of 3 years were the most susceptible to HDMs, and the period from June to November had a high risk of dust mite exposure. Avoiding exposure to particulate matter may have benefits in preventing HDM sensitization in children.

8.
Front Mol Biosci ; 6: 108, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31681796

RESUMO

The gut microbiome plays an important role in the mammalian host and when in proper balance helps protect health and prevent disease. Host environmental stress and its influence on the gut microbiome, health, and disease is an emerging area of research. Exposures to unnatural light cycles are becoming increasingly common due to travel and shift work. However, much remains unknown about how these changes influence the microbiome and host health. This information is needed to understand and predict the relationship between the microbiome and host response to altered sleep cycles. In the present study, we exposed three cohorts of mice to different light cycle regimens for 12 consecutive weeks; including continuous light, continuous dark, and a standard light dark regimen consisting of 12 h light followed by 12 h of dark. After exposure, motor and memory behavior, and the composition of the fecal microbiome and plasma metabolome were measured. Memory potential was significantly reduced in mice exposed to continuous light, whereas rotarod performance was minimally affected. The overall composition of the microbiome was relatively constant over time. However, Bacteroidales Rikenellaceae was relatively more abundant in mice exposed to continuous dark, while Bacteroidales S24-7 was relatively more abundant in mice exposed to continuous light. The plasma metabolome after the continuous dark exposure differed from the other exposure conditions. Several plasma metabolites, including glycolic acid, tryptophan, pyruvate, and several unidentified metabolites, were correlated to continuous dark and light exposure conditions. Networking analyses showed that serotonin was positively correlated with three microbial families (Rikenellaceae, Ruminococcaceae, and Turicibacteraceae), while tryptophan was negatively correlated with abundance of Bacteroidales S24-7 based on light exposure. This study provides the foundation for future studies into the mechanisms underlying the role of the gut microbiome on the murine host during light-dark stress.

9.
Metabolism ; 101: 153998, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31666193

RESUMO

BACKGROUND: The incidence of growth hormone deficiency (GHD) in adamantinomatous craniopharyngioma (aCP) is significantly higher than in other sellar region tumors, but the possible mechanism is still elusive. A high level of inflammatory responses is another feature of aCP. We investigated the internal connection between interleukin-1α (IL-1α) and GHD, while focusing on its biological activities in pituitary fibrosis. MATERIALS AND METHODS: To diagnosis of GHD, the Body Mass Index (BMI), Insulin Like Growth Factor-1(IGF-1) and peak growth hormone (GH) values after insulin stimulation test of 15 aCP patients were recorded. Histological staining was performed on the aCP samples. Levels of 9 proinflammatory cytokines in tumor tissue and cell supernatant were detected using Millipore bead arrays. The effect of IL-1α on GH secretion was evaluated in vivo and in vitro. Western blot, qRT-PCR and cell functional assays were used to explore the potential mechanism through which IL-1α acts on GH secretion. The stereotactic ALZET osmotic pump technique was used to simulate aCP secretion of proinflammatory cytokines in rats. Recombinant IL-1α (rrIL-1α) and conditioned media (CM) prepared from the supernatant of aCP cells was infused directly into the intra-sellar at a rate of 1 µl/h over 28 days, and then the effects of IL-1α treatment on pathological changes of pituitary gland and GH secretion were measured. To further confirm whether IL-1α affects GH secretion through IL-1R1, an IL-1R1 blocker (IL-1R1a, 10 mg/kg body weight, once daily) was administered subcutaneously from the first day until day 28. RESULTS: There was a significant positive correlation between pituitary fibrosis and GHD (rS = 0.756, P = 0.001). A number of cytokines, in particular IL-1α, interleukin-8 (IL-8), and monocyte chemoattractant protein-1 (MCP-1), were elevated in tumor tissue and cell supernatant. Only IL-1α showed a significant difference between the GHD group and the No-GHD group (P < 0.001, F = 6.251 in tumor tissue; P = 0.003, F = 1.529 in cell supernatant). IL-1α significantly reduced GH secretion in coculture of GH3 and pericytes. The activation of pericytes induced by IL-1α was mediated by the IL-1R1 signaling pathway. In vivo, IL-1α induces pituitary fibrosis, further leading to a decreased level of GH. This pathological change was antagonized by IL-1R1a. CONCLUSION: This study found that the cross talk between aCP cells and stroma cells in the pituitary, i.e. pericytes, is an essential factor in the formation of GHD, and we propose that neutralization of IL-1α signaling might be a potential therapy for GHD in aCP.

10.
Math Biosci Eng ; 16(6): 7921-7933, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31698647

RESUMO

Background: An increasing number of patients with advanced non-small cell lung cancer (NSCLC) have a poor prognosis and develop progressive disease after receiving conventional treatments. In recent years, several novel therapies have been approved for later lines of therapy of previously treated NSCLC. Erlotinib, an EGFR tyrosine kinase inhibitor, was recommended as the second-line therapy for pre-treated patients. However, the use of erlotinib has been reported to represent different clinical effects and adverse effects. Objectives: The current study was aim to investigate the efficacy and safety of erlotinib versus chemotherapy in pre-treated patients with advanced NSCLC. Methods: Electronic databases were searched for eligible literatures updated on June 2018. Randomized-controlled trials assessing the efficacy and safety of erlotinib in pre-treated NSCLC were included, of which the main outcomes were ORR (objective response rate), PFS (progression-free survival), OS (overall survival) and AEs (adverse events). All the data were pooled with the corresponding 95% confidence interval using RevMan software. Sensitivity analyses and heterogeneity were quantitatively evaluated. Results: A total of 11 randomized controlled trials were included in this analysis. The group of erlotinib did not achieved benefit in progression-free survival (OR = 0.61, 95%CI = 0.33-1.12, P = 0.11), overall survival (OR = 0.98, 95%CI = 0.84-1.15, P = 0.81) as well with the objective response rate (OR = 0.77, 95%CI = 0.36-1.63, P = 0.49), respectively. In the results of subgroup analysis among the patients with EGFR wild-type, there is also no significant differences in overall survival with erlotinib (OR = 0.90, 95%CI = 0.78-1.04, P = 0.15) and progression-free survival (OR = 0.33, 95%CI = 0.09-1.18, P = 0.09). The most common treatment-related adverse events in the erlotinib group is rash (OR = 5.79, 95%CI = 2.12-15.77, P = 0.0006), and neutropenia (OR = 0.02, 95%CI = 0.01-0.10, P ≤ 0.00001) is more found in the control group. In addition, fatigue (P = 0.09) and diarrhea (P = 0.52), the difference between the two groups had no statistical significance. Conclusions: There was no significant difference noted with regard to efficacy and safety between erlotinib vs. chemotherapy as the later-line therapy for previously treated patients with NSCLC, even with subgroup patients who have wild-type EGFR tumors. While, erlotinib might increase the risk of rash, and decrease the risk of neutropenia, compared with the chemotherapy. Further research is needed to develop a database of all EGFR mutations and their individual impact on the differing treatments.

11.
Zhongguo Dang Dai Er Ke Za Zhi ; 21(10): 1028-1032, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31642439

RESUMO

OBJECTIVE: To study the clinical features of neonatal necrotizing enterocolitis (NEC) and risk factors for poor outcomes. METHODS: A retrospective analysis was performed for the clinical data of 121 preterm infants diagnosed with NEC. According to the treatment method, they were divided into a non-surgical group (n=66) and a surgical group (n=55). According to the outcome, they were divided into a survival group (n=76) and a death group (n=45). Clinical features were compared between these groups. Risk factors for poor outcomes were analyzed by multivariate logistic regression analysis. RESULTS: Compared with the non-surgical group, the surgical group had significantly lower corrected gestational age, minimum platelet count, and incidence rate of bloody stool at the onset of NEC (P<0.05). The maximum C-reactive protein (CRP) and mortality rate in the surgical group were significantly higher than those in the non-surgical group (P<0.05). Compared with the survival group, the death group had significantly lower gestational age at birth, birth weight, proportion of small-for-gestational-age infants, and corrected gestational age, body weight and minimum platelet count at the onset of NEC (P<0.05). The incidence of patent ductus arteriosus, rate of use of ibuprofen, maximum CRP and rate of surgical treatment in the death group were significantly higher than those in the survival group (P<0.05). The multivariate logistic regression analysis showed that ibuprofen treatment was a risk factor for death in infants with NEC (OR=9.149, P<0.05). CONCLUSIONS: Ibuprofen treatment increases the risk for death in preterm infants with NEC.


Assuntos
Permeabilidade do Canal Arterial , Enterocolite Necrosante , Humanos , Ibuprofeno , Recém-Nascido , Recém-Nascido Prematuro , Estudos Retrospectivos
12.
Environ Pollut ; 255(Pt 2): 113267, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31574391

RESUMO

In recent years, ozone pollution has become more and more serious in China. Several epidemiological studies have demonstrated the correlation between short-term ozone exposure and several health risks including all-cause mortality, cardiovascular mortality, and respiratory mortality. In this study, the daily ozone exposure levels with 10 km × 10 km resolution were estimated based on satellite data derived from Ozone Monitoring Instrument (OMI) and the monitoring data. The health impacts for potential decrease in the daily ozone concentration and the corresponding economic benefits in 2016 were estimated by applying the environmental Benefits Mapping and Analysis Program-Community Edition (BenMAP-CE) model. By reducing the daily maximum 8-h average concentration of ozone to 100 µg/m3, the estimated avoided all-cause mortalities were 120 × 103 (95% confidence interval (CI): 67 × 103, 160 × 103) cases and the correspondingly economic benefits ranged from 36 to 64 billion CNY using amended human capital (AHC) and willingness to pay (WTP) method in 2016. If the daily maximum 8-h average concentration of ozone were rolled back to 70 µg/m3, the estimated avoided all-cause mortalities were 160 × 103 (95% CI: 98 × 103, 230 × 103) cases and economic benefits ranged from 54 to 95 billion CNY based on AHC and WTP methods.


Assuntos
Poluição do Ar/estatística & dados numéricos , Exposição Ambiental/estatística & dados numéricos , Tecnologia de Sensoriamento Remoto , Poluentes Atmosféricos/análise , Poluição do Ar/análise , China , Exposição Ambiental/análise , Humanos , Modelos Teóricos , Ozônio/análise , Astronave
13.
G3 (Bethesda) ; 9(11): 3663-3672, 2019 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-31506321

RESUMO

Platycladus orientalis is an ecologically important native conifer in Northern China and exotic species in many parts of the world; however, knowledge about the species' genetics and genome are very limited. The availability of well-developed battery of genetic markers, with large genome coverage, is a prerequisite for the species genetic dissection of adaptive attributes and efficient selective breeding. Here, we present a genome-wide genotyping method with double-digestion restriction site associated DNA sequencing (ddRAD-seq) that is effective in generating large number of Mendelian markers for genome mapping and other genetic applications. Using 139 megagametophytes collected from a single mother tree, we assembled 397,226 loci, of which 108,683 (27.4%) were polymorphic. After stringent filtering for 1:1 segregation ratio and missing rate of <20%, the remaining 23,926 loci (22% of the polymorphic loci) were ordered into 11 linkage groups (LGs) and distributed across 7,559 unique positions, with a total map length of 1,443 cM and an average spacing of 0.2 cM between adjacent unique positions. The 11 LGs correspond to the species' 11 haploid genome chromosome number. This genetic map is among few high-density maps available for conifers to date, and represents the first genetic map for P. orientalis The information generated serves as a solid foundation not only for marker-assisted breeding efforts, but also for comparative conifer genomic studies.

14.
Nanoscale ; 11(36): 16907-16918, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31490477

RESUMO

While red is one of the primary colors for display applications, the investigation of visible red emitting perovskites, particularly 2D perovskites, is relatively limited. In this work, we demonstrate a single-phase Ruddlesden-Popper quasi-2D (C3H7NH3)2CsPb2I7 perovskite for red color LEDs. Through increasing the annealing temperature of (C3H7NH3)2CsPb2I7 perovskite thin films, we have successfully achieved tunable emission wavelengths from 654 to 691 nm. Equally important, for all the quasi-2D perovskite LEDs, once the annealing temperature is fixed, the emission spectrum is independent of bias voltages, which is very important for their use in lighting and displays. With the analysis of the crystallinity, morphology, and thermodynamic stability of the quasi-2D perovskite, we find that the obtained (C3H7NH3)2CsPb2I7 perovskite is a single-phase quasi-2D perovskite with only n = 2 phase. Besides, we found that the red shifting of emission wavelength is caused by the increase of perovskite crystal size while increasing the annealing temperature. Our results also show that the temperature-induced color tunability can be applied to a series of quasi-2D perovskites with different alkylammonium cations. Importantly, we find that short alkylammonium spacers offer better electrical properties for efficient current transport and high performance in LED applications. This work contributes to controlling the optoelectronic properties of quasi-2D perovskites via controlling their crystal growth as well as paves the way to realize practical lighting and display applications of perovskite LEDs.

15.
Med Hypotheses ; 133: 109395, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31522108

RESUMO

Peripheral nerve regeneration remains a challenge in tissue engineering and regenerative medicine. However, the existing approaches have limited regenerative capability. 3D-printed nerve conduits with well-defined properties are potent tools to facilitate peripheral nerve regeneration after injuries. Meanwhile, the vascular networks within the constructs can promote the exchange of oxygen, neurotrophic factors, and removal of waste products, thereby providing an advantageous microenvironment for tissue regeneration. It will be an interesting approach to integrate 3D-printed nerve conduit with vascular networks for the guidance of regenerated nerves. We hypothesize that 3D-printed vascularized nerve conduit will be an effective platform to promote nerve regeneration and functional restoration.

16.
J Anal Methods Chem ; 2019: 4264738, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31531262

RESUMO

A simple, rapid, and reliable method based on dispersive solid-phase extraction (d-SPE) and gas chromatography-mass spectrometry (GC-MS) was developed for quantitating polychlorinated biphenyls (PCBs) in vegetable samples. Parameters affecting both the extraction yields and cleanup efficiency, including the type and volume of extraction solvent, extraction time, type and volume of cleanup sorbent, and cleanup time, were optimized. Matrix effects were evaluated, and matrix-matched calibration was recommended. Under the optimized conditions, carboxylated multiwalled carbon nanotubes (MWCNTs-COOH), which exhibit excellent adsorption capabilities due to large surface area and unique structure, were employed as d-SPE sorbent to remove interfering substances, rather than the analytes, from vegetable samples. Satisfactory linear relationship was observed for all PCBs across a concentration range of 5-500 µg/kg with correlation coefficients no less than 0.9993. Four representative vegetables (cucumber, tomato, lettuce, and cabbage) were selected as matrices for method validation. Each matrix was spiked at concentrations of 5, 10, and 100 µg/kg to evaluate recoveries, which ranged from 84.5% to 116.5% with relative standard deviations (n=6) between 0.6% and 17.6%. The limits of detection and the limits of quantification ranged from 0.3 to 1.4 µg/kg and 0.8 to 4.5 µg/kg, respectively. Twelve real vegetable samples were analyzed using the proposed method. Three of the target PCBs were detected in one lettuce sample with the total concentration of 17.9 µg/kg.

17.
Chem Commun (Camb) ; 55(72): 10717-10720, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31429442

RESUMO

For over a century, NH3 synthesis via the Haber-Bosch process has brought huge energy costs and high CO2 emission. The electrochemical N2 reduction reaction is an environmentally-benign alternative, which can be driven by renewable energy. In this work, CeO2 nanoparticle-reduced graphene oxide nanocomposites (CeO2-rGO) behave as an efficient non-noble-metal N2 reduction reaction electrocatalyst with excellent selectivity. In 0.1 M Na2SO4, CeO2-rGO achieves a high faradaic efficiency of 4.78% and a large NH3 yield of 16.98 µg h-1 mgcat.-1 at -0.7 V vs. reversible hydrogen electrode. The catalytic mechanism was explored using density functional theory calculations.

18.
ACS Appl Mater Interfaces ; 11(39): 36205-36212, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31469274

RESUMO

Highly ordered organic semiconductor single-crystal (OSSC) arrays are ideal building blocks for functional organic devices. However, most of the current methods are only applicable to fabricate OSSC arrays of a single component, which significantly hinders the application of OSSC arrays in integrated organic circuits. Here, we present a universal approach, termed three-dimensional (3D) wettability-induced sequential assembly that can programmatically and progressively manipulate the crystallization locations of different organic semiconductors at the same spatial position using a 3D microchannel template, for the fabrication of the two-component OSSC arrays. As an example, we successfully prepared two-component, bilayer structured OSSC arrays consisting of n-type N,N'-bis(2-phenylethyl)-perylene-3,4:9,10-tetracarboxylic diimide and p-type 6,13-bis(triisopropylsilylethynyl)pentacene microbelts. The bicomponent OSSCs show ambipolar carrier transport properties with hole and electron mobilities of 0.342 and 0.526 cm2 V-1 s-1, respectively. Construction of complementary inverters is further demonstrated based on the two-component OSSCs. The capability of integration of multicomponent OSSC arrays opens up unique opportunities for future high-performance organic complementary circuits.

19.
Ecol Evol ; 9(13): 7528-7548, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31346420

RESUMO

Determining the factors promoting speciation is a major task in ecological and evolutionary research and can be aided by phylogeographic analysis. The Qinling-Daba Mountains (QDM) located in central China form an important geographic barrier between southern subtropical and northern temperate regions, and exhibit complex topography, climatic, and ecological diversity. Surprisingly, few phylogeographic analyses and studies of plant speciation in this region have been conducted. To address this issue, we investigated the genetic divergence and evolutionary histories of three closely related tree peony species (Paeonia qiui, P. jishanensis, and P. rockii) endemic to the QDM. Forty populations of the three tree peony species were genotyped using 22 nuclear simple sequence repeat markers (nSSRs) and three chloroplast DNA sequences to assess genetic structure and phylogenetic relationships, supplemented by morphological characterization and ecological niche modeling (ENM). Morphological and molecular genetic analyses showed the three species to be clearly differentiated from each other. In addition, coalescent analyses using DIYABC conducted on nSSR variation indicated that the species diverged from each other in the late Pleistocene, while ecological niche modeling (ENM) suggested they occupied a larger area during the Last Glacial Maximum (LGM) than at present. The combined genetic evidence from nuclear and chloroplast DNA and the results of ENM indicate that each species persisted through the late Pleistocene in multiple refugia in the Qinling, Daba, and Taihang Mountains with divergence favored by restricted gene flow caused by geographic isolation, ecological divergence, and limited pollen and seed dispersal. Our study contributes to a growing understanding of the origin and population structure of tree peonies and provides insights into the high level of plant endemism present in the Qinling-Daba Mountains of Central China.

20.
Sensors (Basel) ; 19(14)2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31340606

RESUMO

According to the characteristics of the temperature distribution of the thrust sliding bearing bush, the principle and method of quasi-distributed fiber Bragg grating (FBG) sensing is used to measure it. The key problems such as calibration, arrangement and lying of optical FBG sensors are studied by using the simulated thrust sliding bearing bush, which was customized in the laboratory. Combined with the thrust sliding bearing bush, the measurement experiments were carried out, which were divided into two groups: Steady-state experiments and transient experiment. The steady-state experiments obtain the temperature data measured by the FBG temperature sensors at each setting temperature, and the transient experiment obtains the relationship between the measured temperature by each temperature sensor and time in the heating and cooling process. The experimental results showed that the FBG temperature sensors had good accuracy, stability and consistency when measuring the temperature distribution of bearing bush.

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