• Mcmillan Egelund opublikował 1 rok, 3 miesiące temu

    Furthermore, using a tunable ps Raman pump with broadband Raman probe on both the Stokes and anti-Stokes sides, we collected the pre-resonance ground-state femtosecond stimulated Raman spectroscopy (GS-FSRS) data with mode assignments aided by quantum calculations. Key vibrational marker bands at ~850, 1050, 1615, and 1649 cm-1 of the Pr conformer exhibit a notable blueshift to those of the Pg conformer inside AnPixJg2, reflecting the PCB chromophore terminal D (major) and A (minor) ring twist along the primary photoswitching reaction coordinate. This integrated ultrafast spectroscopy and computational platform has the potential to elucidate photochemistry and photophysics of more CBCRs and photoactive proteins in general, providing the highly desirable mechanistic insights to facilitate the rational design of functional molecular sensors and devices.Surface enhanced Raman spectroscopy based on rapid pretreatment combined with Chemometrics was used to determine chlorpyrifos residue in tea. Au nanoparticles were used to as enhance substrate. Different dosages of PSA and NBC were investigated to eliminate the tea substrate influence. Competitive adaptive reweighted sampling (CARS) was used to optimize the characteristic peaks, and compared to full spectra variables and the experiment selected variables. The results showed that PSA of 80 mg and NBC of 20 mg was an excellent approach for rapid detecting. CARS – PLS had better accuracy and stability using only 1.7% of full spectra variables. SVM model achieved better performance with R2p = 0.981, RMSEP = 1.42 and RPD = 6.78. Recoveries for five unknown concentration samples were 98.47 ~ 105.18% with RSD – 1.53% ~ 5.18%. T-test results showed that t value was 0.720, less than t0.05,4 = 2.776, demonstrating that no clear difference between the real value and predicted value. The detection time of a single sample is completed within 15 min. This study demonstrated that SERS coupled with Chemometrics and QuEChERS may be employed to rapidly examine the chlorpyrifos residue in tea towards its quality and safety monitoring.Supramolecular hydrogels are attracting soft materials with potential applications. In this study, we synthesized a facile gelator (named 2-QF) based on phenylalanine derivative with a Quinoline group. 2-QF can assemble to form hydrogels at room temperature in different colors under low pH values. Moreover, 2-QF was triggered to form a yellow metallohydrogel (2-QF-Zn) at high pH by the coordination between 2-QF and Zn2+. 2-QF-Zn metallohydrogel showed excellent multi-stimuli responsiveness, especially the reversible „on-off” luminescence switching, as induced by base/acid. In addition, at a low concentration, 2-QF can selectively and visibly identify Zn2+ through fluorescence enhancement, and can detect Zn2+ at physiological pH as a chemosensor. Remarkably, 2-QF and 2-QF-Zn exhibited an excellent biocompatibility without cell cytotoxicity, and 2-QF is able to penetrate live HeLa cells and image intracellular Zn2+ by a turn-on fluorescent response, which makes it a potential candidate for biomedical applications.In this study, nanocubes KTaO3-reduced graphene oxide (rGO-KTaO3) photocatalysts were synthesized by a facile hydrothermal method. Different technical methods were carried out to characterize the as-prepared compounds. UV-Vis spectra show that the absorption sideband of the complexes red-shift to visible light region, which enhances the light utilization. Meanwhile, X-ray photoelectron spectroscopy (XPS) reveals that the graphene oxide (GO) in the composite has been partially reduced, leading to more effective electron transport and thus improving the photocatalytic efficiency. Furthermore, photocatalytic degradation efficiency of Methylene blue (MB) and Rhodamine B (RhB) in the presence of rGO-KTaO3 reaches 96% and 98%, which is 10 times of that of KTaO3. The synthesized rGO-KTaO3 has good photocatalytic properties. Moreover, the stability of this photocatalyst is particularly excellent. The detailed mechanism of photocatalysis has been carefully discussed in the article.The interactions of acrylic acid-based super absorbent polymers (SAPs) with water and the hydrogen bonding of water within its three-dimensional network were studied using Raman spectroscopy. The Raman spectra of SAP solutions suggested that both the COO- and CH2 groups of SAPs interact with water. The Raman spectra of pure water and those of SAPs containing approximately 40, 50, and 60% water exhibited a broad band corresponding to the OH-stretching mode of water in the 4000-3000 cm-1 region. This band was separated into three components using a curve-fitting method. The three components at 3200, 3400, and 3600 cm-1 were assigned to the OH-stretching modes of strong hydrogen bonding (SHB), weak hydrogen bonding (WHB), and dangling bond (Dang) species of water, respectively. The fractional areas of the three components were calculated and compared. The changes in the hydrogen bonding of water were compared with those of the water present in SAPs, and their temperature-dependent variations were elucidated. At a water content of approximately 60%, the behavior of the fractional area versus temperature was similar to that of pure water. However, at a water content of approximately 40%, the behavior was significantly different. The fraction of SHB was smaller, and the fraction of WHB was larger than that of pure water. The difference in the CH and COO- peak shifts of SAP, which is a result of the addition of a small percentage of water, was revealed by Raman spectroscopy. The position of the CH2 deformation peak changed linearly. However, the position of the COO- rocking peak did not change significantly up to a water content of 30%, above which it exhibited a rapid shift to lower wavenumbers. This result indicates that the interactions of the CH2 and COO- groups are different.The supported CuO onto the ball-mill prepared clinoptilolite nanoparticles (CNPs) was prepared via an ion exchange process in Cu(II) aqueous solution followed by the calcination process. The CuO-CNP samples with various CuO loading were briefly characterized by XRD, FTIR, and DRS. pHpzc was varied in the range of 6.3 to 6.8 depending on the amount of loaded CuO in the samples. The band gap energy was estimated by applying the Kubelka-Munk equation on the DRS results that varied from 2.41 to 2.50 eV depending on the CuO loading. Based on the Scherrer equation nano-sized CuO-CNP at about 50 nm was estimated. The CuO-CNP contained 3.9% CuO showed the highest photocatalytic activity toward dichloroaniline (DCA). The effects of the experimental variables on DCA photodegradation were studied by using the Hinshelwood model. The optimal conditions for obtaining a higher rate for DCA photodegradation were the catalyst dose of 0.5 g/L, CDCA 5 ppm, and the initial pH 3. HPLC analysis of the photodegraded DCA solutions for 180 and 300 min gave the degradation extents 71% and 90%, respectively.The amplitude of Fourier spectra for natural scenes falls with spatial frequency (f) and is described by the equation, 1/fα, where exponent α corresponds to the slope of the spectral drop-off. For natural scenes α takes on intermediate values ~1.25, reflecting their scale invariance. It is also well-established that, on average, images with natural scene statistics are preferred to those that deviate from these properties. Although this average pattern of preference for images with the intermediate values of α is robust, there are also marked individual differences in preference for different levels of α. This study investigated the effects of adaptation on average and individual visual preferences for synthetic filtered noise images varying in α. Participant preferences (N = 58) were measured via a 2AFC task prior to adaptation (baseline) and post-adaptation There were 3 adaptation conditions (α = 0.25, 1.25, 2.25) and 5 test levels of α (0.25, 0.75, 1.25, 1.75, 2.25). On average, the adaptation elevated preferences for test images with α matching the adaptor conditions, especially in adaptor conditions, α = 0.25 and 2.25. We also observed marked individual differences in preference for different levels of α. These different preference profiles remained stable throughout the experiment and affected the levels of adaptation observed in different adaptation conditions.Given a large fraction of people’s exposure to urban PM2.5 occur indoors, reducing indoor PM2.5 levels may offer a more feasible and immediate way to save substantial lives and economic losses attributable to PM2.5 exposure. We aimed to estimate the premature mortality and economic loss reductions associated with achieving the newly established Chinese indoor air guideline and a few hypothetical indoor PM2.5 guideline values. We used outdoor PM2.5 concentrations from 1497 monitoring sites in 339 Chinese cities in 2015, coupled with a steady-state mass balance model, to estimate indoor concentrations of outdoor-infiltrated PM2.5. Using province-specific time-activity patterns for urban residents, we estimated outdoor and indoor exposures to PM2.5 of outdoor origin. We then proceeded to use localized census-based concentration-response models and the value of statistical life estimates to calculate premature deaths and economic losses attributable to PM2.5 exposure across urban China. Finally, we estimated pote limits. The findings demonstrate the effectiveness of reducing indoor concentrations of outdoor-originated PM2.5 in saving substantial lives and economic losses in China. The analysis provides quantitative evidence to support the implementation of an indoor air quality guideline or standard for PM2.5.

    Despite a trend in the use of systems epidemiology to fill the knowledge gap between risk-factor exposure and adverse outcomes in the OMICS data, such as the metabolome, seriously hindrances need to be overcome for identifying molecular connections.

    Using male infertility phenotypes and arsenic exposure, we aimed to identify intermediate biomarkers that reflect both arsenic exposure and male infertility with a meet-in-metabolite analysis (MIMA).

    Urinary arsenic levels and metabolome were measured by using inductively coupled plasma-mass spectrometry (ICP-MS) and HPLC-quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS), respectively. To identify arsenic-related metabolic markers (A-MIMA), the intermediate markers were profiled by orthogonal projections to latent structures (OPLS-DA). To detect infertility-related metabolic markers (I-MIMA), the intermediate markers were investigated by weighted gene co-expression network analysis. The key node markers, related to both A-MIMA and I-MIMA, were detersteroidogenesis dysfunction. Testosterone is at the hub between arsenic exposure and male infertility modules and, along with the related metabolic pathways, may service as a potential surrogate marker in risk assessment for male dysfunction due to arsenic exposure.

    From arsenic exposure to male infertility, the arsenic methylation that coupled one-carbon metabolism disruption with oxidation stress may have extended its effect to fatty acid oxidation and steroidogenesis dysfunction. Testosterone is at the hub between arsenic exposure and male infertility modules and, along with the related metabolic pathways, may service as a potential surrogate marker in risk assessment for male dysfunction due to arsenic exposure.

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