Design and morphology control of a thiophene derivative through electrospraying using various solvents

In the present work, electrospraying of an organic molecule is carried out using various solvents, obtaining fibril structures along with a range of distinct morphologies. Solvent characteristics play a major role in determining the morphology of the organic material. A thiophene derivative (7,9-di(thiophen-2-yl)-8H-cyclopentaa]acenaphthylen-8-one) (DTCPA) of donor-acceptor-donor (DAD) architecture is used to study this solvent effect. Seven solvents with decreasing vapour pressure are selected for experiments. Electrospraying is conducted at a solution concentration of 1.5 wt% and a constant applied voltage of 15 kV. Gradual transformation in morphology of the electrospun product from spiked-spheres to only spikes is observed. A mechanism describing this transformation is proposed based on electron micrograph analysis and XRD analysis. These data indicate that the morphological change is due to the synergistic effect of both vapour pressure and dielectric constant of the solvents. Through a reasonable control of the crystallite size and morphology along with the proposal of the transformation mechanism, this study elucidates electrospraying as a prospective method for designing architectures in organic electronics.

Engineering a multi-biofunctional composite using poly(ethylenimine) decorated graphene oxide for bone tissue regeneration

Toward preparing strong multi-biofunctional materials, poly(ethylenimine) (PEI) conjugated graphene oxide (GO_PEI) was synthesized using poly(acrylic acid) (PAA) as a spacer and incorporated in poly( e-caprolactone) (PCL) at different fractions. GO_PEI significantly promoted the proliferation and formation of focal adhesions in human mesenchymal stem cells (hMSCs) on PCL. GO_PEI was highly potent in inducing stem cell osteogenesis leading to near doubling of alkaline phosphatase expression and mineralization over neat PCL with 5% filler content and was approximate to 50% better than GO. Remarkably, 5% GO_ PEI was as potent as soluble osteoinductive factors. Increased adsorption of osteogenic factors due to the amine and oxygen containing functional groups on GO_ PEI augment stem cell differentiation. GO_ PEI was also highly efficient in imparting bactericidal activity with 85% reduction in counts of E. coli colonies compared to neat PCL at 5% filler content and was more than twice as efficient as GO. This may be attributed to the synergistic effect of the sharp edges of the particles along with the presence of the different chemical moieties. Thus, GO_ PEI based polymer composites can be utilized to prepare bioactive resorbable biomaterials as an alternative to using labile biomolecules for fabricating orthopedic devices for fracture fixation and tissue engineering.

Increased physical activity is not enough to recover astrocytic population from dark-rearing. Synergy with multisensory enrichment is required

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The COMT Val158 Met polymorphism as an associated risk factor for Alzheimer disease and mild cognitive impairment in APOE 4 carriers

Background: The aim of this study is to examine the influence of the catechol-O-methyltranferase (COMT) gene (polymorphism Val158 Met) as a risk factor for Alzheimer's disease (AD) and mild cognitive impairment of amnesic type (MCI), and its synergistic effect with the apolipoprotein E gene (APOE). A total of 223 MCI patients, 345 AD and 253 healthy controls were analyzed. Clinical criteria and neuropsychological tests were used to establish diagnostic groups. The DNA Bank of the University of the Basque Country (UPV-EHU) (Spain) determined COMT Val158 Met and APOE genotypes using real time polymerase chain reaction (rtPCR) and polymerase chain reaction (PCR), and restriction fragment length polymorphism (RFLPs), respectively. Multinomial logistic regression models were used to determine the risk of AD and MCI. Results: Neither COMT alleles nor genotypes were independent risk factors for AD or MCI. The high activity genotypes (GG and AG) showed a synergistic effect with APOE epsilon 4 allele, increasing the risk of AD (OR = 5.96, 95% CI 2.74-12.94, p < 0.001 and OR = 6.71, 95% CI 3.36-13.41, p < 0.001 respectivily). In AD patients this effect was greater in women. In MCI patients such as synergistic effect was only found between AG and APOE epsilon 4 allele (OR = 3.21 95% CI 1.56-6.63, p = 0.02) and was greater in men (OR = 5.88 95% CI 1.69-20.42, p < 0.01). Conclusion: COMT (Val158 Met) polymorphism is not an independent risk factor for AD or MCI, but shows a synergistic effect with APOE epsilon 4 allele that proves greater in women with AD.

Increased antiparkinson efficacy of the combined administration of VEGF- and GDNF-loaded nanospheres in a partial lesion model of Parkinson's disease

Current research efforts are focused on the application of growth factors, such as glial cell line-derived neurotrophic factor (GDNF) and vascular endothelial growth factor (VEGF), as neuroregenerative approaches that will prevent the neurodegenerative process in Parkinson's disease. Continuing a previous work published by our research group, and with the aim to overcome different limitations related to growth factor administration, VEGF and GDNF were encapsulated in poly(lactic-co-glycolic acid) nanospheres (NS). This strategy facilitates the combined administration of the VEGF and GDNF into the brain of 6-hydroxydopamine (6-OHDA) partially lesioned rats, resulting in a continuous and simultaneous drug release. The NS particle size was about 200 nm and the simultaneous addition of VEGF NS and GDNF NS resulted in significant protection of the PC-12 cell line against 6-OHDA in vitro. Once the poly(lactic-co-glycolic acid) NS were implanted into the striatum of 6-OHDA partially lesioned rats, the amphetamine rotation behavior test was carried out over 10 weeks, in order to check for in vivo efficacy. The results showed that VEGF NS and GDNF NS significantly decreased the number of amphetamine-induced rotations at the end of the study. In addition, tyrosine hydroxylase immunohistochemical analysis in the striatum and the external substantia nigra confirmed a significant enhancement of neurons in the VEGF NS and GDNF NS treatment group. The synergistic effect of VEGF NS and GDNF NS allows for a reduction of the dose by half, and may be a valuable neurogenerative/neuroreparative approach for treating Parkinson's disease.

Identification of treatments targeting PMLexpressing breast cancers

The main aim of this project is to find a suitable ATO concentration to combine with already approved chemotherapeutic agents to find that synergistic effect in triple negative breast cancer MDA-MB 231 cell line, as a new strategy to treat the disease.

Avaliação da presença de metilparabeno e propilparabeno no ambiente aquático e seus potenciais estrogênicos e a toxicidade aguda.

Atualmente no cenário mundial a qualidade da água tem gerado muitas preocupações, pois milhares de produtos sintéticos são produzidos para facilitar muitas práticas industriais, domésticas e pessoais e com isso diversas substâncias químicas utilizadas para esses fins são introduzidas no meio ambiente. Os parabenos são substâncias químicas utilizadas pelas indústrias farmacêuticas, de alimentos e cosméticos e que cuja função é a conservação, sendo que há muitos questionamentos em relação a sua segurança, pois alguns relatórios têm mostrado que a exposição a esses parabenos pode modular ou perturbar o sistema endócrino e com isso gerar consequências prejudiciais à saúde humana e aos ambientes aquáticos. Esse estudo teve como objetivo avaliar a presença dos Parabenos Metilparabeno e Propilparabeno no ambiente aquático e os seus potenciais estrogênicos e a toxicidade aguda. A metodologia se desenvolveu a partir do ensaio in vitro YES para a determinação da atividade estrogênica, ensaios de toxicidade aguda em Daphnia similis e em Aliivibrio fischeri e a quantificação dos parabenos na água do Rio Maracanã-RJ através da cromatografia líquida acoplada ao espectrômetro de massa. Os resultados obtidos para a CE50 dos MP e PP, a partir do ensaio in vitro YES, foi de 18,91 mgL-1 e 7 mgL-1 e a magnitude da resposta foi de 10-5 e 10-4 menos potente que 17ß-estradiol para o MP e o PP, respectivamente. A partir do ensaio de toxicidade aguda, os valores de CE50 obtidos em Daphnia similis, foi de 29,42 mgL-1 e 9,94 mgL-1e em Aliivibrio fischeri foi de 3,047 mgL-1 e 1,946 mgL-1, respectivamente, com isso observou-se que o PP é mais tóxicos em todos os organismos testados, sendo mais tóxicos para um e menos para outros. A água do Rio Maracanã não foi tóxica para a Daphnia similis em nenhum dos dois pontos, já para o Aliivibrio fischeri foi tóxica em apenas um ponto. As concentrações encontradas de MP e PP foram maiores no ponto onde, de acordo com os parâmetros físico-químicos, a qualidade da água não está dentro dos padrões exigidos pela legislação, sendo quantificados na ordem de ngL-1, contudo é válido ressaltar que os DEs não são encontrados no meio ambiente separados, eles interagem entre si e provocam efeitos aditivos ou sinérgicos, sendo muito difícil de prever qual o efeito, por isso é importante o conhecimento do potencial estrogênico das substâncias simples, pois em um estudo com uma matriz ambiental, pode-se observar se houve algum efeito aditivo ou sinérgico de outras substâncias.

Effects of Cd2+ and Pb2+ on the substrate biofilms in the integrated vertical-flow constructed wetland

The effects of single Cd2+ and Pb2+, and combined Cd2+ and Pb2+ on dehydrogenase activity and polysaccharide content of the substrate biofilms in the integrated vertical-flow constructed wetland (IVCW) were studied. Dehydrogenase activities decreased linearly with the increasing concentrations of Cd2+ and Pb2+ at different times (6, 24, 72, and 120 h). The activities at both 6 and 24 h were significantly higher than that at 72 and 120 h in the case of single and combined treatments. The single Cd2+ and Pb2+ treatments significantly inhibited dehydrogenase activities at concentrations in excess of 20 mu mol/L Cd2+ and 80 mu mol/L Pb2+, respectively. The inhibitory effect of Cd2+ was much greater than that of Pb2+. At the same time, the combined treatment of Cd2+ and Pb2+ Significantly inhibited dehydrogenase activities at all five concentrations studied and the lowest combined concentration was 1.25 mu mol/L Cd2+ and 5 mu mol/L Pb2+. A synergistic effect of Cd2+ and Pb2+ was observed. On the other hand, polysaccharide contents varied unpredictably with the increasing concentrations of Cd2+ and Pb2+ and extended experimental time. There were no significant statistical differences within the range of concentration and time studied, whether singly or in combination. These results implied that the effects of heavy metals on biofilms should be a concern for the operation and maintenance of constructed wetlands.

Relationship between the allelopathic activity and molecular structure of hydroxyl derivatives of benzoic acid and their effects on cyanobacterium Microcystis aeruginosa

The antialgal activities of benzoic acid, 2-hydroxybenzoic acid (salicylic acid), 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 3,5-dihydroxybenzoic acid and 3,4,5-trihydroxybenzoic acid (gallic acid) were studied on the growth of two strains of Microcystis aeruginosa (toxic FACHB 942 and non-toxic 469). The results showed that the sequence of 50% growth inhibition concentration (ErC50) of 6- compounds for both strains of M. aeruginosa followed the same order: gallic acid > 3,5-dihydroxybenzoic acid > 4-hydroxybenzoic acid > salicylic acid > 3-hydroxybenzoic acid > benzoic acid. The position and the numbers of hydroxy groups between the hydroxy group and carboxyl influenced the antialgal effects of phenolic acids. We also investigated the joint effects of benzoic acid, 4-hydroxybenzoic acid and 3,4,5-trihydroxybenzoic acid on the growth of M. aeruginosa ( toxic FACHB 942). The mixture of phenolic allelochemicals showed the synergistic effects.

Aspergillus sp136抗细菌耐药活性成分研究

基于广谱抗细菌耐药性这一思路，本研究中心建立了一套抗细菌耐药性化合物的筛选方法。由此从3000多种西南地区特殊生境的微生物和植物样品提取物中筛选获得17个抗细菌耐药性活性样品。对其中一株来自峨嵋山土样的微生物（Aspergillus sp136）进行了深入研究。通过TLC自显影等方法从其发酵产物中追踪分离得到抗耐药有效成分，并鉴定为烟曲霉酸。 采用多种方法对烟曲霉酸的体外抗细菌耐药活性进行评价。在平板扩散法中，烟曲霉酸表现出对青霉素（β-内酰氨抗生素）的协同抗耐药能力，其活性大约3倍于克拉维酸。在MIC的测试实验中，烟曲霉酸表现出对青霉素（β-内酰氨抗生素）以及非β-内酰氨抗生素如红霉素、四环素、氯霉素、链霉素、卡那霉素、庆大霉素的抗耐药能力。在棋盘格杀菌以及时间致死曲线的研究中，烟曲霉酸也表现出对青霉素、红霉素、四环素的协同抗细菌耐药活性。 在广泛的活性筛选中发现烟曲霉酸对LDLR基因具有上调活性，表明烟曲霉酸可能具有降血脂的活性。 在研究中发现，同空白对照相比，烟曲霉酸使耐药菌（Bacillus cereus NCPF63509）细胞外β-内酰胺酶酶活大幅度下降，而细胞内β-内酰胺酶酶活仅略有上升，这表明烟曲霉酸对β-内酰胺酶分泌过程具有抑制作用。 综述了β-内酰胺酶的研究进展。 A two-step agar diffusion method was established to screen wide spectrum synergistic antibacterial agents. By using this method, 17 active samples against antibiotic resistance were discovered from more than 3000 plants and microbes, which were collected from southwest china. One isolate Aspergillus sp136 collected from E-mei mountain area was selected for further studies. From the metabolites of this strain, a synergistic antibacterial compound was isolated by bioautographic TLC assay-guided fractionation and identified as helvolic acid. The synergistic effect of helvolic acid was confirmed by several methods in vitro. The synergistic effect of helvolic acid with penicillin (β-lactam antibiotics) was about 3 times as that of clavulanic acid with penicillin in agar diffusion assay. In MIC studies, helvolic acid exhibited synergistic effects with β-lactam antibiotics such as penicillin and non β-lactam antibiotics such as erythromycin, tetracycline, kanamycin, streptomycin and gentamycin. In checkerboard and time-kill studies, helvolic acid also exhibited synergistic effects with penicillin, erythromycin and tetracycline. In general screen of bioactivities, helvolic acid upregulate LDLR gene, which was indirectly determined by the activity of fluorescent enzyme. Therefore, helvolic acid might have the ability to lower lipid in blood. Compared with blank control, the extracellular β-lactamase activity decrease significantly and the intracellular β-lactamase activity increase slightly in Bacillus cereus NCPF63509 in the presence of helvolic acid, indicating that the secretion of β-lactamase was inhibited by helvolic acid. The research of β-lactamase was reviewed.

侵蚀环境撂荒地植被恢复与土壤质量的协同效应

探索黄土丘陵区退耕撂荒地植被恢复与土壤相关要素的关系,为生态恢复重建决策提供理论依据。【方法】以中国科学院安塞水土保持实验站墩山退耕不同年限的撂荒地为研究对象,通过植被群落特征调查和土壤质量测试分析等,运用相关和回归分析方法对植被恢复过程中植被与土壤质量的协同效应研究。【结果】在其恢复过程中,植被地上生物量与植被覆盖度呈正相关,它们与土壤容重呈负相关,而与土壤大团聚体、水稳性大团聚体、有机质含量、全氮含量、水解氮含量、速效钾含量、微生物量(C、N、P)以及土壤呼吸强度之间呈正相关,与土壤全磷、速效磷含量无显著相关性。同时,植被地上生物量和植被覆盖度与土壤抗蚀性关系密切,它们与表示土壤抗蚀性能的土壤团聚度、结构系数之间呈正相关,与土壤分散系数、结构体破坏率之间呈负相关。土壤容重与土壤大团聚体、水稳性团聚体含量之间呈负相关,土壤大团聚体含量与水稳性团聚体含量之间亦呈正相关。黄土丘陵区退耕撂荒地植被恢复过程中,土壤质量得到不断恢复提高,并能促进植被的生长繁衍,推动植被恢复演替进展,植被恢复健康和演替的同时,亦进一步推动土壤质量的改善提高,二者之间表现为正向互作效应。

Combination of Carbon Nanotubes with Ni2O3 for Simultaneously Improving the Flame Retardancy and Mechanical Properties of Polyethylene

Effects of multiwalled carbon nanotubes (MWCNTs) and Ni2O3 on the flame retardancy of linear low density polyethylene (LLDPE) have been studied. A combination of MWCNTs and Ni2O3 showed a synergistic effect in improving the flame retardancy of LLDPE compared with LLDPE composites containing MWCNTs or Ni2O3 alone. As a result, the peak value of heat release rate measured by cone calorimeter was obviously decreased in the LLDPE/MWCNTs/Ni2O3 Composites. According to the results from rheological tests, carbonization experiments, and structural characterization of residual char, the improved flame retardancy was partially attributed to the formation of a networklike structure due to the good dispersion of MWCNTs in LLDPE matrix, and partially to the carbonization of degradation products of LLDPE catalyzed by Ni catalyst originated from Ni2O3, More importantly, both viscoelastic characteristics and catalytic carbonization behavior of LLDPE/MWCNTs/Ni2O3 composites acted in concert to result in a synergistic effect in improving the flame retardancy.

Perovskite-Like Mixed Oxides (LaSrMn1-x Ni (x) O4+delta, 0 a parts per thousand currency sign x a parts per thousand currency sign 1) as Catalyst for Catalytic NO Decomposition: TPD and TPR Studies

Catalytic NO decomposition on LaSrMn1-x Ni (x) O4+delta (0 a parts per thousand currency sign x a parts per thousand currency sign 1) is investigated. The activity of NO decomposition increases dramatically after the substitution of Ni for Mn, but decreases when Mn is completely replaced by Ni (x = 1.0). The optimum value is at x = 0.8. These indicate that the catalytic performance of the samples is contributed by the synergistic effect of Mn and Ni. O-2-TPD and H-2-TPR experiments are carried out to explain the change of activity. The former indicates that only when oxygen vacancy is created, could the catalyst show enhanced activity for NO decomposition; the latter suggests that the best activity is obtained from catalyst with the most matched redox potentials (in this work, the biggest Delta T and Delta E values).

Synthesis of different gold nanostructures by solar radiation and their SERS spectroscopy

In this article, a simple and novel photochemical synthesis of different gold nanostructures is proposed using solar radiation. This method is rapid, convenient and of low cost, and can be performed under ambient conditions. By adjusting the concentration of sodium acetate (NaAc), different morphologies of the products can be easily obtained. Without NaAc, the products obtained are mainly polyhedral gold particles; lower concentration of NaAc (0.05 and 0.1 M) accelerates the formation of flowerlike gold nanostructures; while higher concentration of NaAc (0.5 M) facilitates the formation of a variety of gold nanowires and nanobelts. It is found that the morphology change of gold nanaostructures is the result of the synergistic effect of poly(diallyl dimethylammonium) chloride (PDDA), Ac- ions, and the pH value. In addition, the different gold nanostructures thus obtained were used as substrates for surface-enhanced Raman scattering (SERS) with p-aminothiophenol (p-ATP) as the probe molecule.