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1.
Ann Palliat Med ; 9(1): 1-7, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32005057

RESUMO

BACKGROUND: Optimal communication and collaboration between inter-disciplinary health care providers is critical to ensuring high quality patient care. We aimed to quantify the impact on physician-nurse collaboration (PNC) of implementing daily goal sheets (DGSs) in emergency settings. METHODS: The usage of a DGS was administered in morning rounds in an emergency intensive care unit (ICU) for four consecutive months. A Jefferson Scale of Attitudes Toward Physician-Nurse Collaboration (JSAPNC) form was used before (n=113) and after (n=107) the intervention to evaluate the attitudes of PNCs from the perspective of both physicians and nurses. RESULTS: There is a significant positive relation between the attitude to PNC and the participant age, educational background, and professional rank and title before DGS application (P<0.01 for each), whereas there was no significant difference observed after the initiation of the DGS. CONCLUSIONS: The use of a DGS improves physician-nurse collaborations in emergency care settings.

2.
Sci Rep ; 10(1): 952, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31969602

RESUMO

We compared community composition and co-occurrence patterns of phyllosphere fungi between island and mainland populations within a single plant species (Mussaenda kwangtungensis) using high-throughput sequencing technology. We then used 11 microsatellite loci for host genotyping. The island populations differed significantly from their mainland counterparts in phyllosphere fungal community structure. Topological features of co-occurrence network showed geographic patterns wherein fungal assemblages were less complex, but more modular in island regions than mainland ones. Moreover, fungal interactions and community composition were strongly influenced by the genetic differentiation of host plants. This study may advance our understanding of assembly principles and ecological interactions of phyllosphere fungal communities, as well as improve our ability to optimize fungal utilization for the benefit of people.

3.
ACS Appl Mater Interfaces ; 12(5): 5520-5530, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31891473

RESUMO

Radiotherapy (RT) is one of the most widely used cancer treatments in the clinical setting, while hypoxia-associated resistance often occurs. Herein, a PEGylated TaOx-based oxygen-carrying nanoplatform was constructed for triple sensitizing tumor radiotherapy. The high-Z element based hollow mesoporous TaOx nanospheres were prepared following the in situ growth of ultrasmall CuS nanocrystals and then packaged with O2-saturated perfluoropentane (PFP). NIR laser-triggered mild hyperthermia would lead to the increase of intratumoral blood flow, together with the release of O2, the radiotherapeutic efficiency would be enhanced. Alternatively, radiant energy would be deposited inside the tumor by the Ta element, therefore triple sensitization of radiotherapy could be achieved. The in vivo studies showed that the as-prepared nanospheres could achieve almost total inhibition of tumor growth without obvious side effects, which provides new possibilities for multisensitizing tumor radiotherapy.

4.
Bioorg Chem ; 96: 103575, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31962202

RESUMO

Inhibitors of poly (ADP-ribose) polymerase-1 (PARP-1) have shown to be promising in clinical trials against cancer, and many researchers are interested in the development of new PARP-1 inhibitors. Herein, we designed and synthesized 44 novel erythrina derivatives bearing a 1,2,3-triazole moiety as PARP-1 inhibitors. MTT assay results indicated that compound 10b had the most potent anti-proliferative activity against A549 cells among five cancer cells. The enzyme inhibitory activity in vitro of compound 10b was also significantly better than rucaparib. Furthermore, the selectivity index of compound 10b was higher than rucaparib for lung cancer cells. Flow cytometry analysis showed that compound 10b induced apoptosis of A549 cells by the mitochondrial pathway. Western blot analysis indicated that compound 10b was able to inhibit the biosynthesis of PAR effectively, and it was more potent than rucaparib. Also, compound 10b was able to up-regulate the ratio of bax/bcl-2, activate caspase-3, and ultimately induced apoptosis of A549 cells. The combined results revealed that the discovery of novel non-amide based PARP-1 inhibitors have great research significance and provide a better choice for the future development of drugs.

5.
Inflammation ; 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31907686

RESUMO

Disordered glucose and lipid metabolism contributes to the progression of several liver diseases, while the upregulation of phosphatase and tensin homology deleted on chromosome ten (PTEN), a well-known tumour suppressor gene, can improve the condition through metabolic programming. This study first characterized the metabolic profiles and the involvement of PTEN in the hepatic fibrosis induced by Schistosoma japonicum (S. japonicum) to provide a novel clue for metabolism-targeted treatment. Compared with control mice, infected mice showed infiltrated immune cells in their livers, increased levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and decreased glucose levels in their sera. The expression of key enzymes in the glycolytic pathway was significantly increased, and the expression of gluconeogenic genes was distinctly decreased. Moreover, the infection upregulated the hepatic expression of enzymes involved in fatty acid oxidation, which was consistent with the decreased number of lipid droplets in livers and the lowered levels of triglyceride in sera. Consistently, PTEN and its downstream signalling were significantly inhibited. In vitro, soluble egg antigen (SEA) downregulated the expression of PTEN in both the macrophage RAW264.7 cell line and the murine hepatocellular carcinoma HEP1-6 cell line, and induced a metabolic phenotype similar to the in vivo results. Overall, this study showed that S. japonicum infection induced the reprogramming of glucose and lipid metabolism in mice during the period of liver fibrosis and that SEA could act as a modulator to trigger such a metabolic switch in macrophages and hepatocytes. PTEN might play an essential role in mediating these metabolic reprogramming events.

6.
Cancer Manag Res ; 11: 10239-10248, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31824194

RESUMO

Objective: The purpose of this study was to evaluate the cost-effectiveness of the combined use of afatinib and epidermal growth factor receptor (EGFR) testing versus gemcitabine-cisplatin as the first-line treatment for patients with non-small cell lung cancer (NSCLC) in China. Methods: A decision-analytic model, based on clinical phase III trials, was developed to simulate patient transitions. Direct costs were estimated from the perspective of the Chinese healthcare system. Quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICER) were calculated over a 5-year lifetime horizon. Model robustness was conducted in sensitivity analyses. Results: For the base case, EGFR mutation testing followed by afatinib treatment for advanced NSCLC increased 0.15 QALYs compared with standard chemotherapy at an additional cost of $5069.12. The ICER for afatinib maintenance was $33,416.39 per QALY gained. The utility of PFS and the cost of afatinib had the most important impact on the ICER. Scenario analyses suggested that when a patient assistance program (PAP) was available, ICER decreased to $22,972.52/QALY lower than the willingness-to-pay (WTP) threshold of China ($26,508/QALY). Conclusion: Our results suggest that gene-guided maintenance therapy with afatinib with the PAP might be a cost-effective treatment option compared with gemcitabine - cisplatin in China.

7.
ACS Omega ; 4(22): 19977-19982, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31788631

RESUMO

Olfactory is an extremely fine way of perception. However, the process of smelling is prone to various interference factors. Further development to enhance the communication desires an odor-releasing strategy, which could quantitatively offer a variety of fragrances. Here, we report a fully printing strategy to heterogeneously integrate odor-containing materials and protective coating films. Inspired from the fragrance-containing drum structure on the geranium leaf, encapsulated arrays are fully printed on the flexible or rigid substrates with more than 20 spices. Quantitative concentrations of odor molecules can be released from the encapsulated arrays after scraping the protective poly(lactic-co-glycolic) acid (PLGA) shells. Importantly, various odor-based arrays are printed on the same flexible substrate, which permits selective releasing and arbitrary mixing of the spices. Effective odor-releasing properties of encapsulated arrays make them promising for food security and anticounterfeiting, investigating olfactory discrimination abilities, and strengthening olfactory communication.

8.
Microorganisms ; 7(12)2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31835573

RESUMO

Penicillium digitatum is one of the most important pathogens known widely to cause postharvest losses of citrus. It is significant to explore its infection mechanism to improve the control technology of postharvest diseases of citrus. This research aimed to study the changes in gene expression of P. digitatum at its early stages of citrus infection by transcriptomics sequencing and bioinformatics analysis in order to explore the molecular mechanism of its infection. The results showed that genes associated with pathogenic factors, such as cell wall degrading enzymes, ethylene, organic acids, and effectors, were significantly up-regulated. Concurrently, genes related to anti-oxidation and iron transport were equally up-regulated at varying degrees. From this study, we demonstrated a simple blueprint for the infection mechanism of P. digitatum in Citrus reticulata Blanco, which provided a new direction for subsequent pathological research and paves the way for developing new control strategies.

9.
Biomed Res Int ; 2019: 5049248, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31886221

RESUMO

Background: Rapid on-site evaluation (ROSE) is commonly used to evaluate the adequacy of biopsy materials in fine-needle aspiration; however, the diagnostic performance of ROSE during fiber optic bronchoscopy (FOB) biopsy under direct vision is rarely reported. Here, we evaluated the role of ROSE during FOB biopsy of visible lesion in trachea or bronchi. Methods: The role of ROSE was prospectively evaluated in consecutive bronchoscopy specimens obtained between January 2016 and January 2018. The agreement and accuracy between ROSE and final histopathological interpretation were assessed. The frequency and possible reasons for discrepancy between ROSE and definitive histopathology results were identified. Histological and cytological classification was performed according to the International Association for the Study of Lung Cancer, the American Thoracic Society, and the European Respiratory Society (IASLC/ATS/ERS) criteria of lung ADCs classification. Results: The study enrolled 651 patients, of which 33 were excluded because of insufficient cells. Final diagnosis of malignancy was achieved in 462 cases (74.8%), whereas 156 cases (25.2%) were nonmalignant. ROSE and pathology were well correlated for the diagnosis of squamous cell carcinoma (SCC) (Kappa = 0.718, p < 0.05), adenocarcinoma (AdC) (Kappa = 0.662; p < 0.05) and small cell lung cancer (SCLC) (Kappa = 0.955; p < 0.05). In 24 cases diagnosed as malignant by ROSE and nonmalignant by pathology, the lesion tissues were surgically excised and re-analyzed, and the 24 cases were finally confirmed as malignant by pathology. Conclusions: ROSE technique allows bronchoscopists to obtain viable and adequate material for the diagnosis of histopathology, and provides them with an onsite preliminary diagnosis especially in cases with inconclusive macroscopic appearance. ROSE and pathology should be used in combination to increase the accuracy of diagnosis.

10.
Sensors (Basel) ; 19(23)2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31766586

RESUMO

With the rapid development of unmanned aerial vehicle in space exploration and national defense, large-scale wireless sensor network (WSN) became an important and effective technology. It may require highly accurate locating for the nodes in some real applications. The dynamic node topology control of a large-scale WSN in an unmanned region becomes a hot research topic recently, which helps improve the system connectivity and coverage. In this paper, a hybrid optimization based on two different virtual force algorithms inspired by the interactions among physical sensor nodes is proposed to address the self-consistent node deployment in a large-scale WSN. At the early stage, the deployment algorithm was to deploy the sensor nodes by leveraging the particle motions in dusty plasma to achieve the hexagonal topology of the so-called "Yukawa crystal". After that, another virtual exchange force model was combined to present a hybrid optimization, which could yield perfect hexagonal topology, better network uniformity, higher coverage rate, and faster convergence speed. The influence of node position, velocity, and acceleration during the node deployment stage on the final network topology are carefully discussed for this scheme. It can aid engineers to control the network topology for a large number of wireless sensors with affordable system cost by choosing suitable parameters based on physical environments or application scenarios in the near future.

11.
Artif Cells Nanomed Biotechnol ; 47(1): 4172-4181, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31713440

RESUMO

Diabetic cardiomyopathy (DCM) is an important cardiac disorder in patients with diabetes. High glucose (HG) levels lead to inflammation of cardiomyocytes, oxidative stress, and long-term activation of autophagy, resulting in myocardial fibrosis and remodelling. Astragaloside-IV (AS-IV) has a wide range of pharmacological effects. This study aimed to investigate the effects of AS-IV on injury induced by HG in rat cardiomyocytes (H9C2(2-1)) and the involvement of the miR-34a-mediated autophagy pathway. An AS-IV concentration of 100 µM was selected based on H9C2(2-1) cell viability using the cell counting kit-8 (CCK-8). We found that 33 mM HG induced a morphologic change in cells and caused excessive oxidative stress, whereas AS-IV inhibited lipid peroxidation and increased superoxide dismutase activity. In terms of mRNA expression, HG increased miR-34a and inhibited Bcl2 and Sirt1, whereas AS-IV and miR-34a-inhibitor reversed the above effects. Further, LC3-GFP adenovirus infection and western blotting showed that HG increased autophagy, which was reversed synergistically by AS-IV and miR-34a-inhibitor. Bcl2 and pAKT/AKT protein expressions in the HG group was significantly lower than that in controls, but AS-IV and miR-34a-inhibitor antagonized the process. Thus, AS-IV inhibits HG-induced oxidative stress and autophagy and protects cardiomyocytes from injury via the miR-34a/Bcl2/(LC3II/LC3I) and pAKT/Bcl2/(LC3II/LC3I) pathways.

12.
Onco Targets Ther ; 12: 8105-8115, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31632063

RESUMO

Background: Colorectal cancer (CRC) is one of the most common malignancies worldwide. Studies have demonstrated that epigenetic modifications play essential roles in the development of CRC. ADHFE1 is a differentially expressed gene that has been reported to be hypermethylated in CRC. However, the role and mechanism of ADHFE1 in the proliferation of CRC remain unclear. Materials and methods: ADHFE1 expression was analyzed in CRC tissues by IHC and qRT-PCR, and the relationship between ADHFE1 expression and the clinicopathological parameters was analyzed. Cell proliferation were assessed by the in vitro and in vivo experimental models. GSEA assay was performed to explore the mechanism of ADHFE1 in the proliferation of CRC. Flow cytometry and Western blot were used to detect the activation of the cell cycle signaling. Bisulfite genomic sequence (BSP) assay was used to test the methylation degree of ADHFE1 gene promoter in CRC tissues. Results: Here, we verified that ADHFE1 was down-regulated and hypermethylated in CRC tissues. The down-regulation of ADHFE1 was correlated with poor differentiation and advanced TNM stage of CRC patients. And ADHFE1 expression restored when the CRC cell line SW620 was treated with the demethylating agent 5-Aza-CdR. Overexpression of ADHFE1 inhibited the proliferation of CRC, while ADHFE1 knockdown promoted the proliferation of CRC cells in vitro and in vivo. Moreover, ADHFE1 overexpression could induce a significant G1-S cell cycle arrest in CRC cells and vice versa. Conclusion: Hypermethylation of ADHFE1 might promote cell proliferation by modulating cell cycle progression in CRC, potentially providing a new therapeutic target for CRC patients.

13.
Microorganisms ; 7(11)2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31652932

RESUMO

Green mold disease, a common citrus post-harvest disease caused by Penicillium digitatum, has an unresolved initial infection mechanism. Understanding the infection mechanism leads to the development of potential controls and preventive measures against the disease. The present study aimed to delineate the infection mechanism by investigating spore germination, changes of organic molecules and enzyme activity, and differential expression of genes in the P. digitatum infection. P. digitatum spore germination was observed by a pathology section scanner and it was found that in vivo germination was 3 h behind the in vitro germination. In addition, cell wall degrading enzymes and soluble sugar and titratable acid content during the infection process measured dynamically. The level of pectinase reached its maximum of 6067 U/g before 48 hpi, while cellulase increased rapidly after 48 hpi. The soluble sugar and organic acid content increased considerably with the progression of the infection. The transcriptomic profile of P. digitatum before and after infection was analyzed by RNA-seq. The genes related to cell wall degrading enzymes were significantly up-regulated and annotated to participate in two major carbon source synthesis pathways. The study delineated the initial infection mechanism of P. digitatum which eventually opened the gate way for the development of new control strategies in the future.

14.
PeerJ ; 7: e7787, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31608171

RESUMO

Plastomes of heterotrophs went through varying degrees of degradation along with the transition from autotrophic to heterotrophic lifestyle. Here, we identified the plastome of mycoheterotrophic species Burmannia itoana and compared it with those of its reported relatives including three autotrophs and one heterotroph (Thismia tentaculata) in Dioscoreales. B. itoana yields a rampantly degraded plastome reduced in size and gene numbers at the advanced stages of degradation. Its length is 44,463 bp with a quadripartite structure. B. itoana plastome contains 33 tentatively functional genes and six tentative pseudogenes, including several unusually retained genes. These unusual retention suggest that the inverted repeats (IRs) regions and possibility of being compensated may prolong retention of genes in plastome at the advanced stage of degradation. Otherwise, six rearrangements including four inversions (Inv1/Inv2/Inv3/Inv4) and two translocations (Trans1/Trans2) were detected in B. itoana plastome vs. its autotrophic relative B. disticha. We speculate that Inv1 may be mediated by recombination of distinct tRNA genes, while Inv2 is likely consequence of extreme gene losses due to the shift to heterotrophic lifestyle. The other four rearrangements involved in IRs and small single copy region may attribute to multiple waves of IRs and overlapping inversions. Our study fills the gap of knowledge about plastomes of heterotroph in Burmannia and provides a new evidence for the convergent degradation patterns of plastomes en route to heterotrophic lifestyle.

15.
Ann Vasc Surg ; 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31655109

RESUMO

BACKGROUND: The neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) are 2 markers of inflammation, which are associated with worse cardiovascular disease outcomes. Here, we aimed to determine the association between these ratios and disease severity and evaluate predictive validity of the NLR and PLR in lower limb arteriosclerosis obliterans (ASO). METHODS: We evaluated 211 patients with a diagnosis of ASO from January 2016 to December 2018 at Shanghai Jiaotong University Renji Hospital. The NLR and PLR were accessed from routinely drawn peripheral venous blood at the ward of vascular surgery during hospitalization. The association between the NLR and PLR with baseline characteristics, disease severity, and one-year outcomes were determined, respectively. RESULTS: Both the NLR and PLR showed significant values on predicting disease severity. A higher NLR (P = 0.001) and PLR (P < 0.001) were associated with lower ankle-brachial index and worse clinical presentation. Both the NLR and PLR are positively correlated with one-year readmission rate (P < 0.001, P = 0.001, respectively). Both the NLR and PLR also positively correlated with the tissue loss rate and one-year mortality (P = 0.007, P = 0.034, respectively). CONCLUSIONS: The NLR and PLR show a positive association with the severity of lower extremity peripheral artery disease, both higher ratios correlate with poor prognosis, especially, the risk of one-year readmission. A higher NLR also correlates with one-year mortality.

16.
Sci Total Environ ; 697: 134073, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31473547

RESUMO

The improvement of urban river revetment soil is conducive to promote the growth of pioneer plants which can accelerate the restoration of ecosystems. How to effectively amend soil structure and composition to provide a suitable soil rhizosphere for rapid plant expansion is essential to be solved in the study. Biochar and lake dredged sediments were used to amend an urban river bank soil, where compaction and lack of mineral nutrition hindered the growth of Phragmites. The study found that the addition of 50% mass of dredged sediments combined with 5% mass of straw biochar increased the plant height maximum growth rate, tiller number per unit area, and root biomass by 32.93%, 29.62%, and 41.39%, respectively. The reason for these positive effects on plant growth mainly involved the improvement of rhizosphere soil properties. Addition of biochar increased porosity and available phosphorus content while dredged sediments increased soil organic carbon, thereby increasing the underground unit total phosphorus content of Phragmites by 18.18%. An increase of the Alpha diversity index of rhizosphere microorganisms (8.18%) and the decrease in infection rate of arbuscular mycorrhizal fungi (23.61%) also proved that the rapid expansion of Phragmites was improved owing to changes of the soil physicochemical properties. The combination of biochar and dredged sediments realized synergistic improvement of soil physical structure and increase of nutrient content, which helped promote the growth and expansion of the underground part of Phragmites. This cost-effective method can be feasible used for improvement of urban river revetment ecosystem.


Assuntos
Recuperação e Remediação Ambiental/métodos , Poaceae/crescimento & desenvolvimento , Rizosfera , Microbiologia do Solo , Carvão Vegetal/química , Micorrizas , Fotossíntese
17.
Cancer Res ; 79(20): 5151-5158, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31416845

RESUMO

miRNAs are key players in the integrated regulation of cellular processes and shape many of the functional properties that define the "cancer stem cell" (CSC) phenotype. Little is known, however, about miRNAs that regulate such properties in human colorectal carcinoma. In this study, we compared the expression levels of 754 miRNAs between paired samples of EpCAM+/CD44+ cancer cells (enriched in CSCs) and EpCAM+/CD44neg cancer cells (with CSC depletion) sorted in parallel from human primary colorectal carcinomas and identified miR-221 as the miRNA that displayed the highest level of preferential expression in EpCAM+/CD44+ cancer cells. High levels of miR-221 expression were associated with Lgr5+ cells in mouse colon crypts and reduced survival in patients with colorectal carcinoma. Constitutive overexpression of miR-221 enhanced organoid-forming capacity of both conventional colorectal carcinoma cell lines and patient-derived xenografts (PDX) in vitro. Importantly, constitutive downregulation of miR-221 suppressed organoid-forming capacity in vitro and substantially reduced the tumorigenic capacity of CSC populations from PDX lines in vivo. Finally, the most abundant splicing isoform of the human Quaking (QKI) gene, QKI-5, was identified as a functional target of miR-221; overexpression of miR-221-reduced QKI-5 protein levels in human colorectal carcinoma cells. As expected, overexpression of QKI-5 suppressed organoid-forming capacity in vitro and tumorigenic capacity of colorectal carcinoma PDX cells in vivo. Our study reveals a mechanistic link between miR-221 and QKI and highlights their key role in regulating CSC properties in human colorectal cancer. SIGNIFICANCE: These findings uncover molecular mechanisms underlying the maintenance of cancer stem cell properties in colon cancer.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/20/5151/F1.large.jpg.

18.
BMJ Open ; 9(7): e023981, 2019 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-31362958

RESUMO

INTRODUCTION: Sepsis commonly results in acute kidney injury (AKI), whereas about 50% of AKI cases are due to sepsis. Sepsis-associated acute kidney injury (SA-AKI) increases morbidity and mortality especially among critically ill patients. This study aims to monitor renal microcirculation perfusion during sepsis using contrast-enhanced ultrasonography (CEUS), and to explore whether CEUS is useful for predicting the development of SA-AKI. METHODS AND ANALYSIS: This prospective observational study will enrol patients who were diagnosed with sepsis-3 definition. The total of septic or septic shock patients were stratified into AKI (including stages 1, 2 and 3) and non-AKI groups according to Kidney Disease Improving Global Outcomes criteria on days 0, 1, 2 and 7 after admission to the emergency intensive care unit, meanwhile, the CEUS technique will be performed to monitor renal microcirculation perfusion. A multivariable model including all CEUS variables were expected to create for predicting the development of AKI during sepsis. Ultrasonography results, demographic information, therapeutic interventions, survival outcomes, laboratory and other clinical datas will also be collected for further analysis. ETHICS AND DISSEMINATION: The study protocol was approved on 2 August 2017 by the Ethics Committee of Sir Run Run Shaw Hospital (Zhejiang University Medical College) (approval number: 2016C91401). The results will be published in a peer-reviewed journal and shared with the worldwide medical community within 2 years after the start of the recruitment. TRIAL REGISTRATION NUMBER: ISRCTN14728986.

19.
Sci Total Environ ; 694: 133591, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31386956

RESUMO

Although heavy metal monitoring campaigns are established worldwide, it is still difficult to model heavy metals in aquatic environments with limited monitoring data. In this study, surface water physicochemical indexes and heavy metal concentrations were measured in a drinking water source in the Taihu Lake region, China. Afterwards, indexes including water temperature, pH, suspended matter, turbidity, and total nitrogen, nitrate nitrogen, ammonia nitrogen, total phosphorous, orthophosphate and permanganate index were used to simulate dissolved, particulate and total heavy metal concentrations using artificial neural network (ANN) and support vector machine (SVM) models. Sensitivity analysis showed that simulated heavy metal concentrations were most sensitive to pH. Thereafter, quick simulation models based on five sensitive parameters (pH, suspended matter, water temperature, total phosphorus and permanganate index) allowed for quick simulations of heavy metal concentrations were built. Both ANN and SVM quick simulation models simulated particulate heavy metal concentrations well with most Nash-Sutcliffe efficiency coefficients >0.8. Models performed worse when simulating dissolved and total heavy metal concentrations. Results demonstrate that artificial intelligence models like ANN and SVM are alternative ways to simulate heavy metal concentrations with limited monitoring data. Furthermore, sensitivity analysis may help to identify key factors affecting heavy metal behavior, and to improve environmental monitoring campaigns and management strategies.

20.
Environ Sci Technol ; 53(16): 9789-9799, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31328514

RESUMO

Few studies have focused on the association between previous particulate matter (PM) exposure and antioxidant defense response to a haze challenge. In this study, a combined exposure model was used to investigate whether and how PM exposure history affected the antioxidant defense response to haze episodes. At first, C57BL/6 male mice were randomly assigned to three groups and exposed for 5 weeks to whole ambient air, ambient air containing a low (≤75 µg/m3) PM concentration, and filtered air, which simulated different exposure history of high, relatively low, and almost zero PM concentrations. Thereafter, all mice underwent a 3-day haze exposure followed by a 7-day exposure to filtered air. The indexes involved in the primary and secondary antioxidant defense response were determined after pre-exposure and haze exposure, as well as 1 day, 3 days, and 7 days after haze exposure. Our research demonstrated repeated exposure to a high PM concentration compromised the antioxidant defense response and was accompanied by an increased susceptibility to a haze challenge. Conversely, mice with a lower PM exposure developed an oxidative stress adaption that protected them against haze challenge more efficiently and in a more timely manner than was the case in mice without PM exposure history.


Assuntos
Poluentes Atmosféricos , Material Particulado , Animais , Antioxidantes , Pulmão , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Tamanho da Partícula
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