166 research outputs found
Subphthalocyanines, Phthalocyanines and Azulenocyanines: Red and NIR-Absorbing Dyes for Molecular Photovoltaics
Tesis doctoral inédita leída en la Universidad Autónoma de Madrid. Facultad de Ciencias, Departamento de Química Orgánica. Fecha de lectura: 23-07-201
Photoinduced energy transfer in ZnCdSeS quantum dot-phthalocyanines hybrids
In this article, interaction between ZnCdSeS quantum dot (QD) and phthalocyanines with variable linker has been reported. Steady-state and time-resolved spectroscopic investigation reveals that only photoinduced energy transfer occurs from QD to phthalocyanines. To evaluate quantitatively the energy transfer, the Poisson statistics of QD-dye complex formation was used in the analysis of steady-state and time-resolved emission quenching, which allows to estimate the energy transfer rate constant for an ideal one-to-one complex. The measured rate constants are compared to the rates evaluated based on the classic Förster theory, which shows roughly 1 nm discrepancy in the energy transfer distance estimation, or one order in magnitude discrepancy in the transfer rate constants.S.M. is grateful to the TUT postdoctoral programme. T.T. is grateful for the financial support of the MINECO, Spain (CTQ2017-85393-P), the Comunidad de Madrid (FOTOCARBON, S2013/MIT-2841). IMDEA Nanociencia acknowledges support from the ‘Severo Ochoa’ Programme for Centres of Excellence in R&D (MINECO, Grant SEV-2016-0686)
Farklı eğe sistemlerinin kök kanallarından kalsiyum hidroksiti uzaklaştırmadaki etkinliklerinin değerlendirilmesi
Amaç: Tek köklü dişlerden farklı eğe sistemlerini kullanarak
kanal içi ilaç olan kalsiyum hidroksit’in (KH)
uzaklaştırılmasının değerlendirilmesidir.
Gereç ve Yöntemler: Bu çalışmada 30 adet tek köklü
çekilmiş insan dişi kullanıldı. Kök kanalları ProTaper F4
eğesine kadar genişletildi. KH patı kök kanallarına çalışma
uzunluklarında yerleştirildi. Köklerin koronal kısımlarına
pamuk pelet ve geçici bir dolgu maddesi konularak
kapatıldı. Daha sonra dişler distile su içinde 37oC’de 7 gün
boyunca bekletildi. Sonrasında geçici dolgular kaldırıldı.
Kök kanallarındaki KH’ın uzaklaştırılmasında kullanılan
yönteme göre örnekler rastgele dört deney grubu
(ProTaper Universal F4, ProTaper Next X4, Reciproc 40,
WaveOne Large) ve kontrol grubu olmak üzere toplam 5
gruba (n=12) ayrıldı. Kökler bukko-lingual olarak ikiye
ayrıldı ve kanal içerisinde kalan artık KH miktarı x 15
büyütmede stereomikroskop altında değerlendirildi. Veriler
SPSS programında Cronbach alpha yöntemi ile istatistiksel
olarak değerlendirildi.
Bulgular: KH’in kök kanallarından tamamen
uzaklaştırılamadığı görüldü. Reciproc eğe sistemi ile
istatistiksel olarak diğer gruplardan daha fazla KH’i
uzaklaştırıldığı belirlendi (P < 0.05). Kontrol grubunda diğer
gruplardan daha az KH uzaklaştırılmasına rağmen ProTaper
Universal, ProTaper Next ve WaveOne eğe sistemleriyle
aralarında istatistiksel olarak anlamlı bir fark görülmedi
(P > 0.05).
Sonuç: Reciproc eğe sisteminin NaOCl ile birlikte kullanımı
kök kanallarından KH’i uzaklaştırmada yalnızca NaOCl
kullanımından veya ProTaper Universal, ProTaper Next ve
WaveOne eğe sistemlerinden daha etkili olduğu
görülmüştür. Ancak, kullanılan tekniklerin hiçbiri kök
kanallarından KH’i tamamen uzaklaştıramamaktadır
Vitamin D deficiency in pregnancy may affect fetal thymus development
Objectives: The aim of our study was to evaluate the association of vitamin D deficiency (VDD) during pregnancy with thymus size in full-term fetuses.
Material and methods: In this prospective study, we evaluated mid-pregnancy serum 25-hydroxyvitamin D3 (25(OH)D3) concentrations. The fetal thymus size was measured by ultrasound in the third trimester. Neonatal 25(OH)D3 levels were evaluated by umbilical cord blood sampling. Correlation of maternal and neonatal vitamin D levels and association between thymus size and both, maternal and neonatal vitamin D concentrations were investigated.
Results: Serum 25(OH) D3 concentrations were within the normal range in 48 (29.8%) mothers and 10 (13.1%) newborns. A strong correlation between mid-pregnancy maternal and neonatal 25(OH)D3 concentration (r = 0.8, p < 0.001) was found. A significant linear correlation was observed between both, maternal and neonatal 25(OH)D3 concentrations and thymus perimeter length (r = 0.45, p = 0.04 and r = 0.43, p < 0.01, respectively). Both, maternal and fetal VDDs were associated with decreased thymus perimeter (p = 0.04, p = 0.03).
Conclusions: Vitamin D deficiency during pregnancy may be associated with smaller fetal thymus. Our data suggest that VDD in pregnancy may lead to systemic inflammatory response in the fetus
Selective Photokilling of Human Pancreatic Cancer Cells Using Cetuximab-Targeted Mesoporous Silica Nanoparticles for Delivery of Zinc Phthalocyanine
Background: Photodynamic therapy (PDT) is a non-invasive and innovative cancer therapy based on the photodynamic effect. In this study, we sought to determine the singlet oxygen production, intracellular uptake, and in vitro photodynamic therapy potential of Cetixumab-targeted, zinc(II) 2,3,9,10,16,17,23,24-octa(tert-butylphenoxy))phthalocyaninato(2-)-N29,N30,N31,N32 (ZnPcOBP)- loaded mesoporous silica nanoparticles against pancreatic cancer cells. Results: The quantum yield (Φ∆) value of ZnPcOBP was found to be 0.60 in toluene. In vitro cellular studies were performed to determine the dark- and phototoxicity of samples with various concentrations of ZnPcOBP by using pancreatic cells (AsPC-1, PANC-1 and MIA PaCa-2) and 20, 30, and 40 J/cm2 light fluences. No dark toxicity was observed for any sample in any cell line. ZnPcOBP alone showed a modest photodynamic activity. However, when incorporated in silica nanoparticles, it showed a relatively high phototoxic effect, which was further enhanced by Cetuximab, a monoclonal antibody that targets the Epidermal Growth Factor Receptor (EGFR). The cell-line dependent photokilling observed correlates well with EGFR expression levels in these cells. Conclusions: Imidazole-capped Cetuximab-targeted mesoporous silica nanoparticles are excellent vehicles for the selective delivery of ZnPcOBP to pancreatic cancer cells expressing the EGFR receptor. The novel nanosystem appears to be a suitable agent for photodynamic therapy of pancreatic tumor
Photophysicochemical properties and photodynamic therapy activity of highly water-soluble Zn (II) phthalocyanines
The syntheses of two zinc(II) phthalocyanines (ZnPcs) having either imidazole (ZnPc 1) or pyridiloxy (ZnPc 2) moieties as their macrocycle substituents are reported. Quaternization of the ZnPcs with methyl iodide afforded water soluble cationic phthalocyanines. The photophysical, photochemical properties and photodynamic therapy (PDT) activity of the ZnPcs were studied in solution. The fluorescence quantum yield and lifetime of ZnPc 1 were higher as compared to ZnPc 2. ZnPc 2 afforded higher triplet state (ΦT) and singlet oxygen quantum yields (ΦΔ) in comparison to ZnPc 1. The PDT activity of ZnPcs was investigated against human breast adenocarcinoma cells (MCF–7). The two compounds afforded a very minimal in vitro dark cytotoxicity with 85% viable cells at concentration ≤80 μM. On irradiation of the cells having the ZnPcs, ≥50% cell death was recorded for ZnPc 1 which was also evidenced by the cells photo–micrograph
Targeted Genetic Screen in Amyotrophic Lateral Sclerosis Reveals Novel Genetic Variants with Synergistic Effect on Clinical Phenotype
Amyotrophic lateral sclerosis (ALS) is underpinned by an oligogenic rare variant architecture. Identified genetic variants of ALS include RNA-binding proteins containing prion-like domains (PrLDs). We hypothesized that screening genes encoding additional similar proteins will yield novel genetic causes of ALS. The most common genetic variant of ALS patients is a G4C2-repeat expansion within C9ORF72. We have shown that G4C2-repeat RNA sequesters RNA-binding proteins. A logical consequence of this is that loss-of-function mutations in G4C2-binding partners might contribute to ALS pathogenesis independently of and/or synergistically with C9ORF72 expansions. Targeted sequencing of genomic DNA encoding either RNA-binding proteins or known ALS genes (n = 274 genes) was performed in ALS patients to identify rare deleterious genetic variants and explore genotype-phenotype relationships. Genomic DNA was extracted from 103 ALS patients including 42 familial ALS patients and 61 young-onset (average age of onset 41 years) sporadic ALS patients; patients were chosen to maximize the probability of identifying genetic causes of ALS. Thirteen patients carried a G4C2-repeat expansion of C9ORF72. We identified 42 patients with rare deleterious variants; 6 patients carried more than one variant. Twelve mutations were discovered in known ALS genes which served as a validation of our strategy. Rare deleterious variants in RNA-binding proteins were significantly enriched in ALS patients compared to control frequencies (p = 5.31E-18). Nineteen patients featured at least one variant in a RNA-binding protein containing a PrLD. The number of variants per patient correlated with rate of disease progression (t-test, p = 0.033). We identified eighteen patients with a single variant in a G4C2-repeat binding protein. Patients with a G4C2-binding protein variant in combination with a C9ORF72 expansion had a significantly faster disease course (t-test, p = 0.025). Our data are consistent with an oligogenic model of ALS. We provide evidence for a number of entirely novel genetic variants of ALS caused by mutations in RNA-binding proteins. Moreover we show that these mutations act synergistically with each other and with C9ORF72 expansions to modify the clinical phenotype of ALS. A key finding is that this synergy is present only between functionally interacting variants. This work has significant implications for ALS therapy development
Sulu ortamda fotokatalizör olarak kullanılabilecek bir ftalosiyanin türevinin sentezlenmesi ve fotokatalizör olarak uygulanması
Subftalosiyaninler (SubPc) merkezde bor atomu bulunan üç izoindol üniteden olusmus, 14 -elektron sisteminin delokalize oldugu aromatik ve koni biçimindeki yapılardır. Bu tezde, öncelikle farklı substitüe (nitro-, metoksi-, metoksifenoksi-) gruplar içeren ftalonitril türevleri, birkaç basamakta sentezlenmistir. Elde edilen ftalonitril türevleri SubPc sentezinde baslangıç maddesi olarak kullanılmıstır. Elde edilen ürünlerin yapıları UVgörünür, fluoresans, FT-IR, 1H NMR ile aydınlatılarak, bu türevlerin, TGA ile termal dayanımları, DÖNGÜSEL VOLTAMETRE ile redoks potansiyelleri tespit edilerek, fotofiziksel ve fotokimyasal özellikleri ortaya konmustur. Metilen mavisinin, SubPc bilesikleri kullanılarak günes ve yogunlastırılmıs günes ısıgı altındaki fotooksidatif degradasyonu incelenmistir. Degradasyon miktarları UVgörünür spektrofotometresi ile takip edilmistir
Membrane fouling in thermophilic membrane bioreactor with different sludge retention times
As membrane fouling is based on various factors, it is a complex phenomenon that is hard to estimate. This study investigated membrane fouling in a thermophilic jet loop membrane bioreactor (JLMBR). With this purpose, four different empirical membrane fouling models with different sludge retention times were applied on the flow data obtained in the system. As a result of the model implementation, it was found for all sludge retention times that, standard blocking is effective in the first 1.5 hours of filtration, while cake filtration was dominant in the remaining duration. Additionally, it was observed that as the sludge retention time increases, membrane fouling rate decreases. © 2018 Techno-Press, Ltd.110Y134The research described in this paper was financially supported by TUBITAK (The Scientific and Technological Research Council of Turkey) (grant number 110Y134)
Morphological features of thermophilic activated sludge treating food industry wastewater in MBR
Microscopic examination of the activated sludge and morphological characterization of the flocs provides detailed information about the treatment process. The aim of this study is to investigate the morphological parameters of flocs obtained from a thermophilic jet loop membrane bioreactor (JLMBR) in different sludge retention times (SRTs), considering EPS and SMP concentration, hydrophobicity, zeta potential. The results showed that irregularity decreased with the increasing SRT. The compactness value was calculated to be less than 1 for all SRTs. However, the sludge had a more compact structure when the SRT increased. Zeta potential increased whereas hydrophobicity and floc size reduced, with increasing SRT. Furthermore, 2-D porosity calculated using the hole ratio was higher at greater SRTs. Hence, there was a significant correlation between the results obtained using the imaging technique and operation conditions of thermophilic JLMBR. © 2018 Techno-Press, Ltd.110Y134This study was financially supported by the Scientific and Technological Research Council of Turkey (TUBITAK) with the project number 110Y134
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