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1.
Dalton Trans ; 49(23): 7945-7951, 2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32495779

RESUMO

Four heteroleptic Ir(iii) complexes (Ir-1-Ir-4) with varied π-conjugated diimine ligands were synthesized. Their optical properties were investigated systematically via spectroscopic methods, in order to elucidate the influence of the extended π-conjugation on the singlet and triplet states of the molecules. All these Ir(iii) complexes exhibit ligand localized 1π,π* transitions below 370 nm, and broad metal-to-ligand and ligand-to-ligand charge transfer (MLCT/LLCT) absorption bands in the visible region. Extending the π-conjugation in diimine ligands influences the electron distribution of the triplet state. The 3π,π* dominated Ir(iii) complexes (Ir-3 and Ir-4) exhibit long-lived triplet states and low phosphorescence quantum yields, compared with the charge transfer dominated Ir(iii) complexes (Ir-1 and Ir-2). Complexes Ir-3 and Ir-4 exhibit broadband transient absorption spectra from 420 to 750 nm, between which the nonlinear absorption could be observed by virtue of reverse saturable absorption. The results of nonlinear transmission measurements using 532 nm laser pulses further elucidate that selected complexes Ir-3 and Ir-4 are promising candidates for optical limiting applications.

2.
Spinal Cord ; 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32415223

RESUMO

STUDY DESIGN: Cross-sectional descriptive study. OBJECTIVES: To compare the diffusion tensor imaging (DTI) changes of the sacral cord in people with complete cervical spinal cord injury (SCI) and neurogenic bladder versus people without SCI, and to explore the relationship between sacral cord DTI changes and bladder contractility. SETTING: First Affiliated Hospital of Soochow University, Jiangsu Province, China. METHODS: Forty participants were included: 25 participants with complete cervical SCI and 15 without SCI. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were calculated by DTI for ventral horn and intermediate column of sacral cord at S2-S4 level. All participants underwent urodynamic examination. The urodynamic parameters (voiding efficiency (VE), and bladder contractility index (BCI)) and DTI parameters were compared between people with and without SCI. The correlations between DTI values (FA and ADC) and urodynamic parameters were analyzed. RESULTS: The FA values were significantly lower and the ADC values were significantly higher in the intermediate column and ventral horn at S2-S4 level of the participants with SCI compared with their able-bodied counterparts (p < 0.05). VE and BCI were significantly different between the two groups (p < 0.05). The FA values of intermediate column positively correlated with BCI (r = 0.749, p < 0.05) and the ADC values negatively correlated with BCI (r = -0.471, p < 0.05) in participants with SCI. The DTI values of sacral cord were not correlated with each urodynamic parameter in participants without SCI (p > 0.05). CONCLUSIONS: Complete cervical SCI might lead to microstructural changes of the sacral cord, which might further affect bladder contraction.

3.
Oncol Rep ; 43(5): 1606-1618, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32323798

RESUMO

Accumulating evidence suggests that lncRNAs are involved in almost all normal physiological processes and that aberrant expression of lncRNAs may be involved in the development of diseases, including non­small cell lung cancer (NSCLC). However, the roles of lncRNA­TPTE pseudogene 1 (TPTEP1) in lung cancer and the underlying molecular mechanisms have remained elusive. In the present study, significant downregulation of TPTEP1 in tumors compared with normal tissues from patients with NSCLC was observed. Overexpression of TPTEP1 inhibited cell proliferation and induced apoptosis in NSCLC cells. A bioinformatics analysis based on miRDB predicted microRNA (miR)­328­5p as a potential binding miRNA for TPTEP1. Using a dual­luciferase reporter assay and western blot analysis, it was further validated that TPTEP1 sponged miR­328­5p to upregulate Src kinase signaling inhibitor 1 (SRCIN1) in NSCLC cells. Through regulation of SRCIN1, TPTEP1 was indicated to inactivate the Src and STAT3 pathways in NSCLC cells. Notably, silencing of SRCIN1 reversed the TPTEP1 overexpression­induced inhibition of cell proliferation and increase of the apoptotic rate in NSCLC cells. Pearson correlation analysis revealed a significant positive correlation between TPTEP1 and SRCIN1 mRNA levels in NSCLC tumors. The present results provided insight into the roles of TPTEP1 in NSCLC and the underlying mechanisms.

4.
Bioelectrochemistry ; 131: 107352, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31494386

RESUMO

The designed synthesis of efficient materials can significantly enhance the performance of electrochemical immunoassay in the detection of diseases, pesticide residues and environmental pollutants. The hollow AgPt@Pt core-shell nanoparticles (AgPt@Pt HNs) have exhibited high catalytic efficiency to the hydrogen peroxide (H2O2) reduction for its high mass activity from their hollow structure. Their limitation of instability can be overcome by loading on polypyrrole nanosheet (PPy NS). Besides, PPy NS exhibits good conductivity, and there exists environmentally-friendly method for its synthetic. Thus, AgPt@Pt HNs loaded on PPy NS (AgPt@Pt HNs/PPy NS) exhibits high catalytic efficiency to the reduction of H2O2 and good stability. Furthermore, the quick electron transfer of AgPt@Pt HNs/PPy NS modified glassy carbon electrode has been evidenced by the finding that the large constant of apparent electron transfer rate has also enlarged the current signal when the amount of electron is invariant. The modified electrode has fabricated a label-free amperometric immunosensor to detect sensitively prostate-specific antigen (PSA) with H2O2 as the electroactive material. The immunosensor in hollow core-shell nanosheet structure exhibiting good detection performance of PSA shows its promising applications in the clinical diagnosis.


Assuntos
Técnicas Biossensoriais , Eletrodos , Ouro/química , Nanopartículas Metálicas/química , Nanoestruturas/química , Platina/química , Polímeros/química , Pirróis/química , Biomarcadores Tumorais/análise , Catálise , Peróxido de Hidrogênio/química , Limite de Detecção , Oxirredução , Antígeno Prostático Específico/análise
5.
Dalton Trans ; 48(40): 15105-15113, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31559974

RESUMO

Pt(ii) complexes that exhibit long-lived triplet excited state lifetimes are promising for optical power limiting materials. The introduction of large π-conjugated substituents can switch the triplet excited state to a long-lived 3π,π* state. Herein, we report four Pt(ii) diimine complexes with high π-conjugation via inserting an aryl group on the diimine ligand. Their photophysical properties were investigated using spectroscopic techniques. All the complexes exhibit strong ground absorption bands in their UV-Vis absorption spectra (maximum peaks ranging from 370 to 530 nm) and long-lived emission and triplet excited states. The insertion of π-conjugated substituents induces a pronounced red-shift in the ground state absorption and longer emission lifetime. Broadband transient absorption spectra in the visible-NIR region and Z-scan properties under 532 nm were carried out on the Pt(ii) diimine complexes, resulting in a remarkably strong reverse saturable absorption at 532 nm for nanosecond laser pulses. Otherwise, the high π-conjugation in the bipyridyl ligand increases the reverse saturable absorption. Therefore, these Pt(ii) diimine complexes with high π-conjugation are excellent candidates for devices that require strong reverse saturable absorption.

6.
Ann Transl Med ; 7(12): 266, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31355233

RESUMO

Background: To evaluate the efficacy and safety of acupuncture therapies for the treatment of essential hypertension. Methods: We performed a systematic electronic search of PubMed, Embase, the Cochrane Library, Chinese Biomedical Literature Database (CBM), Chinese National Knowledge Infrastructure (CNKI), and Wan-fang Data Database. The main outcome indicators measured were the amount of major adverse cardiovascular events (MACE), a change of blood pressure, and the response rate. STATA15.0 software was used for the network meta-analysis. Results: A total of 31 trials with 2,649 patients were included. Patients were allocated to 15 kinds of interventions. These including acupuncture types were electroacupuncture, moxibustion, warm needle therapy, sham acupuncture, behavioral therapy, angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), calcium channel blocker (CCB), beta-blocker, acupuncture combined ACEI, acupuncture combined CCB, acupuncture combined behavior, electroacupuncture combined CCB, and non-treatment. The results of the network meta-analysis showed that there was no significant clinical or statistic difference in systolic blood pressure (SBP) change magnitude between acupuncture treatment and the other 14 therapies. Moxibustion may be better than acupuncture in reducing diastolic blood pressure (DBP) [mean difference (MD): 15.9, 95% confidence interval (CI): 5.96-25.85]. There was no significant difference in reducing DBP between acupuncture and the other 13 interventions. The effective rate of acupuncture combined with AECI [odds ratio (OR) =7.96, 95% CI: 1.11-56.92] and acupuncture combined with behavioral therapy (OR =3.53, 95% CI: 1.08-11.51) in treating hypertension was better than that of acupuncture alone, and there was no statistically significant difference in the effective rate between acupuncture and the other therapies. Conclusions: The existing evidence shows that acupuncture could be used for treating hypertension, and it may have the same effects as common medication. However, due to the low qualities of the original studies, the quality of this evidence is poor. Therefore, it is recommended that more scientific research be performed to confirm the efficacy of acupuncture.

8.
Oncol Lett ; 17(1): 1108-1114, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30655872

RESUMO

Curcumin, a polyphenol derived from the rhizome of Curcuma, is a potential tumor inhibitor through affecting signaling pathways and epigenetic regulation. The mammalian target of rapamycin (mTOR) gene serves a crucial role in the carcinogenesis of multiple myeloma. The curcumin-induced epigenetic regulation of mTOR, including promoter DNA methylation in multiple myeloma, has not yet been fully elucidated. In the present study, antitumor effects of curcumin were investigated in RPMI-8226 and NCI-H929 cells using an MTT assay and flow cytometry. The expression of mTOR and DNA methyltransferase proteins were determined by western blot analysis, and the methylation status of the mTOR promoter were detected by sequencing following bisulfite conversion. The results of the present study revealed that the half-maximal inhibitory concentration of curcumin was 10 µM in myeloma cells. Following curcumin treatment, the mRNA and protein expression levels of mTOR were decreased by 43.31 and 39.34% in NCI-H929 cells, respectively. The promoter of mTOR, located in chromosome 1 (chromosome position, 11262153-11263153), contains a CpG island that was hypermethylated in myeloma cells following curcumin treatment. The expression levels of DNA methyltransferase (DNMT)3a and DNMT3b were increased in curcumin-treated cells. Collectively, these results indicate that curcumin serves a role in the epigenetic regulation of mTOR expression, and that mTOR downregulation is due to promoter hypermethylation, which may be associated with DNMT3a and DNMT3b upregulation. The results of the present study contribute towards improving the understanding of curcumin treatment in multiple myeloma and provide novel insights into the molecular mechanisms underlying the epigenetic regulation of mTOR.

9.
Int Heart J ; 59(6): 1320-1326, 2018 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-30369567

RESUMO

Cardiac resynchronization therapy (CRT) improves heart function and prognosis in third-degree atrioventricular block (AVB) patients with heart failure (HF). However, it is still unclear how to screen for appropriate patients before implantation. This study aimed to evaluate the value of using QRS duration to predict CRT efficacy.This study enrolled a total of 72 third-degree AVB patients with HF who received CRT implantation. The patients were divided into Groups A (QRS duration < 120 ms, 33 cases), B (120 ms ≤ QRS duration < 150 ms, 22 cases), and C (QRS duration ≥ 150 ms, 17 cases) according to their baseline QRS duration. The effects of different QRS durations on CRT efficacy were analyzed.The CRT response rate were 30.3%, 50.0%, and 76.5% in Groups A, B, and C, respectively (P = 0.008). The patients in the 3 groups showed significant changes in left ventricular (LV) end-diastolic volume, LV end-systolic volume, and LV ejection fraction over the baseline values at 12 months after the implantation (P < 0.05), with the greatest change observed in Group C. Survival analysis indicated statistically significant differences among Groups A, B, and C (P = 0.024). Multivariate logistic regression analysis suggested that QRS duration was an independent prognostic factor for CRT efficacy. Baseline QRS duration was associated with improved myocardial remodeling and reductions in the incidence rates of primary endpoint events.QRS ≥ 150 ms is an effective predictor of postoperative outcome in patients with third-degree AVB and HF treated with CRT.


Assuntos
Bloqueio Atrioventricular/terapia , Terapia de Ressincronização Cardíaca , Insuficiência Cardíaca/etiologia , Idoso , Idoso de 80 Anos ou mais , Bloqueio Atrioventricular/complicações , Bloqueio Atrioventricular/mortalidade , Bloqueio Atrioventricular/fisiopatologia , Feminino , Seguimentos , Insuficiência Cardíaca/mortalidade , Humanos , Estimativa de Kaplan-Meier , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Prognóstico , Resultado do Tratamento
10.
Molecules ; 23(8)2018 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-30065217

RESUMO

Polysaccharides from Ascophyllum nodosum (AnPS) were extracted and purified via an optimized protocol. The optimal extraction conditions were as follows: extraction time of 4.3 h, extraction temperature of 84 °C and ratio (v/w, mL/g) of extraction solvent (water) to raw material of 27. The resulting yield was 9.15 ± 0.23% of crude AnPS. Two fractions, named AnP1-1 and AnP2-1 with molecular weights of 165.92 KDa and 370.68 KDa, were separated from the crude AnPS by chromatography in DEAE Sepharose Fast Flow and Sephacryl S-300, respectively. AnP1-1 was composed of mannose, ribose, glucuronic acid, glucose and fucose, and AnP2-1 was composed of mannose, glucuronic acid, galactose and fucose. AnPS, AnP1-1 and AnP2-1 exhibited high scavenging activities against ABTS radical and superoxide radical, and showed protective effect on H2O2-induced oxidative injury in RAW264.7 cells. Furthermore, the immunostimulatory activities of AnP1-1 and AnP2-1 were evaluated by Caco-2 cells, the results showed both AnP1-1 and AnP2-1 could significantly promote the production of immune reactive molecules such as interleukin (IL)-8, IL-1ß, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α. Therefore, the results suggest that AnPS and its two fractions may be explored as a potential functional food supplement.


Assuntos
Adjuvantes Imunológicos/isolamento & purificação , Antioxidantes/isolamento & purificação , Ascophyllum/química , Extração Líquido-Líquido/métodos , Polissacarídeos/isolamento & purificação , Adjuvantes Imunológicos/química , Adjuvantes Imunológicos/farmacologia , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Células CACO-2 , Sobrevivência Celular/efeitos dos fármacos , Cromatografia DEAE-Celulose , Fucose/química , Fucose/isolamento & purificação , Galactose/química , Galactose/isolamento & purificação , Ácido Glucurônico/química , Ácido Glucurônico/isolamento & purificação , Humanos , Peróxido de Hidrogênio/antagonistas & inibidores , Peróxido de Hidrogênio/farmacologia , Interferon gama/biossíntese , Interferon gama/imunologia , Interleucina-1beta/biossíntese , Interleucina-1beta/imunologia , Interleucina-8/biossíntese , Interleucina-8/imunologia , Manose/química , Manose/isolamento & purificação , Camundongos , Polissacarídeos/química , Polissacarídeos/farmacologia , Células RAW 264.7 , Solventes/química , Sulfatos/química , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/imunologia , Água/química
11.
J Cell Biochem ; 119(9): 7707-7718, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29904944

RESUMO

Like other tumors, lung cancer must induce angiogenesis as it grows. Hypoxia-inducible factor 1α (HIF-1α) is the inducible subunit of the HIF-1 transcription factor that regulates genes involved in the response to hypoxia, some of which contributes to angiogenesis. Vascular endothelial growth factor (VEGF) is one of the genes upregulated by HIF-1 and is the primary cytokine in relation to angiogenesis. In this study we tested whether aberrant activation of hypoxia inducible factor-1α/vascular endothelial growth factor (HIF-1α/VEGF) pathway correlates with response to radiotherapy and examined the response of lung cancer cells to hypoxia in vitro. We determined increased expressions of HIF-1α and VEGF-A in 76 cancerous tissues of responders (complete remission and partial remission). HIF-1α and VEGF-A were shown to be upregulated in lung cancer cells in response to hypoxia. The treatment with anti-HIF-1α siRNA prior to hypoxia exposure was shown to decrease HIF-1α and VEGF-A expressions and reduce hypoxia-induced angiogenesis, suggesting that HIF-1α expression resulted in increased VEGF-A expression and activation of HIF-1α/VEGF pathway was responsible for hypoxia-induced angiogenesis. In conclusion, we identified the relationship between HIF-1α/VEGF pathway and response to radiotherapy and its role in angiogenesis in lung cancer in vitro. HIF-1α/VEGF pathway as a target for antiangiogenic treatment strategies for this tumor requires further investigation.


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neoplasias Pulmonares/radioterapia , Regulação para Cima/efeitos da radiação , Fator A de Crescimento do Endotélio Vascular/genética , Células A549 , Adulto , Idoso , Animais , Hipóxia Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/antagonistas & inibidores , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Masculino , Camundongos , Pessoa de Meia-Idade , RNA Interferente Pequeno/farmacologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/efeitos da radiação , Resultado do Tratamento , Fator A de Crescimento do Endotélio Vascular/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
12.
BMC Cancer ; 18(1): 635, 2018 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-29866064

RESUMO

BACKGROUND: Obesity is found to increase the risk of most cancer types, but reduce lung cancer risk in many studies. However, the association between obesity and lung cancer is still controversial, mainly owing to the confounding effect of smoking. METHODS: Eligible studies were identified from electric databases to July 1, 2017. Relevant data were extracted and pooled using random-effects models; dose-response and subgroup analyses were also performed. RESULTS: Twenty-nine studies with more than 10,000 lung cancer cases in15 million never smokers were included. Compared with normal weight, the summary relative risk (RR) was 0.77(95% confidence interval [CI]: 0.68-0.88, P < 0.01) for excess body weight (body mass index [BMI] ≥ 25 kg/m2). An inverse linear dose-response relationship was observed between BMI and lung cancer risk in never smokers, with an RR of 0.89(95% CI: 0.84-0.95, P < 0.01) per 5 kg/m2 increment in BMI. The results remained stable in most subgroup analyses. However, when stratified by sex, a significant inverse association existed in women but not in men. Similar results were found in analyses for other categories of BMI. CONCLUSION: Our results indicate that higher BMI is associated with lower lung cancer risk in never smokers.


Assuntos
Neoplasias Pulmonares/epidemiologia , Obesidade/complicações , Índice de Massa Corporal , Humanos , Fatores de Risco , Fumantes
13.
Org Lett ; 20(9): 2778-2781, 2018 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-29688020

RESUMO

A metal-free hydrophosphorylation of ynamides with diaryl phosphine oxides has been developed. A highly E-selective and ß-regioselective hydrophosphorylation protocol has been established as a general method for the synthesis of diversely hydrophosphinylated products employing an in situ generated electrophilic phosphorus species. Deuterium incorporation experiments suggest that the amino phosphirenium intermediate undergoes a concerted ring-opening hydrolysis upon treatment with H2O to exclusively furnish ß-aminovinylphosphine oxides.

14.
Int J Biol Macromol ; 112: 1055-1061, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29425873

RESUMO

Sulfated polysaccharides from marine algae exhibit various bioactivities with potential benefits for human health and well-being. In this study, the in vitro digestibility and fermentability of polysaccharides from the brown seaweed Ascophyllum nodosum (AnPs) were examined, and the effects of AnPs on gut microbiota were determined using high-throughput sequencing technology. Salivary amylase, artificial gastric juice, and intestinal juice had no effect on AnPs, but the molecular weight of AnPs and reducing sugar decreased significantly after fermentation by gut microbiota. AnPs significantly modulated the composition of the gut microbiota; in particular, they increased the relative abundance of Bacteroidetes and Firmicutes, suggesting the potential for AnPs to decrease the risk of obesity. Furthermore, the total SCFA content after fermentation increased significantly. These results suggest that AnPs have potential uses as functional food components to improve human gut health.


Assuntos
Ascophyllum/química , Microbioma Gastrointestinal/efeitos dos fármacos , Polissacarídeos/farmacologia , Sulfatos/farmacologia , Bactérias/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Ácidos Graxos/metabolismo , Fermentação , Humanos
15.
ACS Appl Mater Interfaces ; 9(38): 33029-33040, 2017 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-28862832

RESUMO

Recently, graphene-based materials have become well-known nonlinear optical materials for the potential application of laser protection. Two new graphene oxide-platinum  complex (GO-Pt) hybrid materials (GO-Pt-1, GO-Pt-2) have been fabricated through covalent modification and electrostatic adsorption of different Pt complexes with GO. The structural and photophysical properties of the resultant hybrid materials were studied. The nonlinear optical properties and optical power limiting (OPL) performance of Pt complexes, GO, and GO-Pt hybrid materials were investigated by using Z-scan measurements at 532 nm. At the same transmittance, the results illustrate that functionalization of GO makes GO-Pt hybrid materials possess better nonlinear optical properties and OPL performance than individual Pt complexes and GO due to a combination of nonlinear scattering, nonlinear absorption, and photoinduced electron and energy transfer between GO and Pt complex moieties. Furthermore, the nonlinear optics and OPL performance of GO-Pt-2 are better than those of GO-Pt-1, due to not only the excellent optical limiting of Pt-2 and more molecules per area of GO but also the way of combination of Pt-2 and GO.

16.
Org Biomol Chem ; 15(34): 7218-7226, 2017 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-28816329

RESUMO

A highly regio- and stereoselective trans-iodofluorination reaction of ynamides with NIS and Et3N·3HF has been achieved, affording (E)-α-fluoro-ß-iodoenamides in moderate to good yields. The reaction proceeds under mild reaction conditions and exhibits good functional group compatibility.


Assuntos
Amidas/química , Amidas/síntese química , Halogenação , Iodo/química , Catálise , Técnicas de Química Sintética , Estereoisomerismo
17.
Org Biomol Chem ; 15(14): 2923-2930, 2017 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-28290578

RESUMO

An attractive and novel methodology involving Pd/Cu-catalyzed tandem head-to-tail dimerization/cycloisomerization of terminal ynamides for the synthesis of 3,5-disubstituted oxazolones was developed. Under Pd(PPh3)2Cl2/CuI cooperative catalyzed reaction conditions, it provided efficient access to 5-vinyloxazolones with exceptional functional group tolerance and good chemoselectivity. The control experiments demonstrated that Pd(PPh3)2Cl2 serves a key role in the dimerization of terminal ynamides and shows low catalytic activity in the intramolecular cyclization. Moreover, the hetero-Diels-Alder reaction of product 5-vinyloxazolones was also described, which provided polycyclic oxazolones in good yield.

18.
Mar Pollut Bull ; 116(1-2): 156-166, 2017 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-28065549

RESUMO

The time taken for spilt oil to appear firstly at the sea surface and its location are two key issues for emergency response. The underwater spread of oil spill in a shear flow was studied experimentally in a re-circulating water channel. The high speed imaging technology was employed to record the whole transport process of oil spilt from a leak of a submarine pipe to the surface. Based on the experimental results, three underwater transport types are identified, which are single droplet pattern (model A), linear chain pattern (model B) and oil plume pattern (model C), respectively. The pressure difference inside and outside of the leak determines the underwater transport pattern. For single droplet pattern, the transport of oil droplet has two successive stage, namely the accumulation stage and the buoyant droplet stage. When it comes to linear chain pattern, the first stage changes to be the initial jet stage. Besides the initial jet stage and the buoyant droplet stage, oil plume pattern has an intermediate transition stage, namely the plume development stage. During the whole floating process, the pressure difference dominates the initial stage, while droplet buoyancy is the driven force in the rest. The required time for oil droplets to reach the surface is increased with the decreasing of the initial momentum and the increasing of the shear flow velocity. In the buoyance dominated stage, the floating rate of oil droplets is basically unchanged and the horizontal migration rate is similar with the shear flow velocity. Both the break-up and coalescence of oil droplets have two forms, which are single droplet splitting and droplet-column separation for break-up form and turbulence merging and pursuit merging for coalescence form, respectively.


Assuntos
Modelos Teóricos , Poluição por Petróleo/análise , Poluentes Químicos da Água/análise , Água do Mar
19.
Biosens Bioelectron ; 91: 424-430, 2017 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-28064127

RESUMO

A novel thionine unites with platinum nanowire inlaid globular SBA-15 (Pt NWs@g-SBA-15/Thi) not only utilizes as an efficient electrical signal probe but also constitutes an amplifying system with double-deck gold film (D-Au film) have been applied to the fabrication of sandwich-type immunosensor for detecting hepatitis B surface antigen (HBs Ag). The D-Au film can accelerate the electron transfer on the electrode interface due to the tunneling effect between the two Au films and can improve the load capacity of primary antibodies (Ab1) because of the good biocompatibility. The Pt NWs@g-SBA-15/Thi with uniform globular morphology not only can effectively reduce the spatial limitation for loading the secondary antibodies (Ab2) but also can provide outstanding pore accessibility of guest species from outside and offer catalytically active sites in a large scale. Besides, the presence of Thi can well enhance the electrical conductivity of Pt NWs@g-SBA-15/Thi. With the good cooperation between D-Au film and Pt NWs@g-SBA-15/Thi, a linear relationship between current signals and the concentrations of HBs Ag was obtained in the wide range from 10 fg/mL to 100ng/mL and the detection limit of HBs Ag was 3.3 fg/mL (signal-to-noise ratio of 3). Furthermore, the designed immunosensor with excellent selectivity, reproducibility and stability shows excellent performance in detection of human serum samples and provides a promising capacity for detecting a wide range of other tumor markers in clinical application.


Assuntos
Técnicas Eletroquímicas/métodos , Antígenos de Superfície da Hepatite B/sangue , Vírus da Hepatite B/isolamento & purificação , Hepatite B/sangue , Nanofios/química , Fenotiazinas/química , Platina/química , Anticorpos Imobilizados/química , Técnicas Biossensoriais/métodos , Ouro/química , Antígenos de Superfície da Hepatite B/análise , Humanos , Imunoensaio/métodos , Limite de Detecção , Nanofios/ultraestrutura , Reprodutibilidade dos Testes , Dióxido de Silício/química
20.
Pest Manag Sci ; 73(5): 917-924, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27427282

RESUMO

BACKGROUND: Anthranilic diamide derivatives are among the most important classes of synthetic insecticides. Moreover, the 1,2,4-oxadiazole heterocycle, a bioisostere of amide, has been extensively used in pesticides. In order to discover novel molecules with high insecticidal activities, a series of anthranilic diamide analogues containing 1,2,4-oxadiazole rings were designed and synthesised. RESULTS: A series of novel anthranilic diamide derivatives containing 1,2,4-oxadiazole were obtained, and confirmed by 1 H and 13 C nuclear magnetic resonance and high-resolution mass spectrometry. The structure of 3-bromo-N-(4-chloro-2-methyl-6-{3-[(methylsulphonyl)methyl]-1,2,4-oxadiazol-5-yl}phenyl)-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carboxamide was further characterised by X-ray diffraction analysis. In addition, bioassays showed that most of the newly synthesised compounds displayed 100% mortality against Plutella xylostella at 100 mg L-1 , and compound 3IIl showed 90% larvicidal activities at a concentration of 0.5 mg L-1 . The LC50 value of 3IIl was 0.20 mg L-1 , which indicated that it may be used as a potential leading compound for further structural optimisation. Furthermore, brief comparative molecular field analysis (CoMFA) models were established to study the structure-activity relationships (SARs) of the title compounds. CONCLUSION: Compound 3IIl may be used as a potential leading compound for further structural optimisation, and SARs and CoMFA models could provide reliable clues for further structural optimisation. © 2016 Society of Chemical Industry.


Assuntos
Diamida/química , Diamida/síntese química , Desenho de Fármacos , Inseticidas/química , Inseticidas/síntese química , Isoxazóis/química , Oxidiazóis/química , Animais , Técnicas de Química Sintética , Modelos Moleculares , Conformação Molecular , Mariposas , Relação Estrutura-Atividade
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