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Recent advances in optical imaging have the potential to significantly improve patient outcomes. Among the most promising approaches under development is contrast-enhanced fluorescence imaging, which can be performed with molecular targeting to enhance tumor visualization. One key issue that has not been rigorously addressed is the potential phototoxicity of these fluorophores. In this study, we have used a commercial cell-free assay to qualify the singlet oxygen production rate in approved (ICG, Methylene Blue) and unapproved (IRDye700, IRDye800) fluorophores. Results shed light on the relative phototoxicity of each agent and will help to establish standardized methods for photochemical safety testing.

Ocular inflammation is a common pathological condition of a series of retinal degenerative diseases. Tetramethylpyrazine (TMP), a Chinese herbal extraction, is widely used in the treatment of several ocular diseases in Eastern countries. However, the exact mechanisms correlating the vision protective effects of TMP have not been elucidated. Thus, this study aimed to investigate TMP's molecular targets in anti-inflammatory activity in endotoxin lipopolysaccharide (LPS)-induced retinal inflammation both in vitro and in vivo. The primary cultured retinal microglial cells were pretreated with TMP and then activated by LPS. We found pretreatment with TMP significantly inhibited LPS-induced upregulation of CD68, a marker of mononuclear microglia activation. The morphological changes induced by LPS were also inhibited by the TMP pretreatment. Moreover, Toll like receptor 4 (TLR4), phosphorylation of inhibitor of NF-κB alpha (p-IκB-α) and the translocation of nuclear factor kappa B p65 (NF-κB p65) were significantly downregulated in retinal microglial cells with TMP pretreatment, which indicated that TMP might suppress LPS-induced retinal microglial activation through TLR4/NF-κB signalling pathway. And these results were confirmed in vivo. Pretreatment with TMP inhibited microglial activation, migration and regeneration, especially in ganglion cell layer (GCL). In addition to the inhibition of TLR4, TMP significantly inhibited the translocation of NF-κB p-65 to the nucleus in vivo. The downstream genes of NF-κB, such as the pro-inflammatory cytokines interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β), were significantly downregulated by TMP pretreatment in the retina. Accordingly, the increased expression of cleaved caspase-3 and the decreased ratio of B-cell lymphoma-2 (Bcl-2) to Bcl-2 associated X Protein (Bax) were significantly attenuated by TMP. TUNEL assay also demonstrated that TMP exerted neuroprotective effects in the retina. Therefore, this study elucidated a novel mechanism that TMP inhibits retinal inflammation by inhibiting microglial activation via a TLR4/NF-κB signalling pathway.

Background Autologous fat grafting has long been an essential technique in cosmetic and reconstructive surgery. Here, the authors report the advantages of a new device for preparing micronized fat, and they also investigated the therapeutic potential of micronized fat against ultraviolet B-induced photoaging. Methods Micronized fat aliquots were prepared through a connector device with trifoliate blades. The histologic structure and viability of the prepared fat samples were evaluated by calcein AM/propidium iodide staining. The levels of growth factor were measured by enzyme-linked immunosorbent assay, and flow cytometry was used to detect the ratio of adipose-derived mesenchymal stem cells to stromal vascular fraction. The authors also evaluated the effects of micronized fat transplantation through immunohistochemistry and Masson trichrome staining in an animal model of photoaging. Results The micronized fat had a normal histologic structure and viable adipocytes. It had a higher level of hepatocyte growth factor compared with the control group, and its ratio of adipose-derived mesenchymal stem cells to stromal vascular fraction was also higher than in the control fat preparations. Transplantation of micronized fat preparations in the animal model of photoaging produced increased skin neovascularization, epidermal cell proliferation, and dermal collagen density. Conclusions The authors' results demonstrated that the novel device produced micronized fat easily, which can condense adipose tissue. This micronized fat was easy to use with smaller cannulas. It mitigated the signs of cutaneous photoaging and was superior to control fat. Contrary to previous reports, normal histologic structures and viable adipocytes were noted in the micronized fat.

The interaction between berberine chloride and β-cyclodextrin (β-CyD) is investigated via 2D asynchronous UV-Vis spectrum. The occurrence of cross peaks around (420nm, 420nm) in 2D asynchronous spectrum reveals that specific intermolecular interaction indeed exists between berberine chloride and β-CyD. In spite of the difficulty caused by overlapping of cross peaks, we manage to confirm that the 420nm band of berberine undergoes a red-shift, and its bandwidth decreases under the interaction with β-CyD. The red-shift of the 420nm band that can be assigned to n-π* transition indicates the environment of berberine becomes more hydrophobic. The above spectral behavior is helpful in understanding why the solubility of berberine is enhanced by β-CyD.

In this work, we investigated the influence of polyvinylpyrrolidone (PVP) on the solubility of artemisinin in aqueous solution by using quantitative 1H NMR. Experimental results demonstrate that about 4 times of incremental increase occurs on the solubility of artemisinin upon introducing PVP. In addition, dipole-dipole interaction between the ester group of artemisinin and the amide group of N-methylpyrrolidone (NMP), a model compound of PVP, is characterized by two-dimensional (2D) correlation FTIR spectroscopy with the DAOSD (Double Asynchronous Orthogonal Sample Design) approach developed in our previous work. The observation of cross peaks in a pair of 2D asynchronous spectra suggests that dipole-dipole interaction indeed occurs between the ester group of artemisinin and amide group of NMP. Moreover, the pattern of cross peaks indicates that the carbonyl band of artemisinin undergoes blue-shift while the bandwidth and absorptivity increases via interaction with NMP, and the amide band of NMP undergoes blue-shift while the absorptivity increases via interaction with artemisinin. Dipole-dipole interaction, as one of the strongest intermolecular interaction between artemisinin and excipient, may play an important role in the enhancement of the solubility of artemisinin in aqueous solution.

In this study, the feasibility of using copper oxide (CuO) as an interface for the coupling of liquid chromatography (LC) and Fourier-transform infrared (FTIR) spectroscopy was investigated. CuO exhibits low absorption in the 4000 to 1000 cm-1 FTIR spectral region. In addition, LC-FTIR using CuO as the interface was extended to the analysis of sample mixtures containing benzamide and dioctyl sebacate; both analytes were successfully separated. After complete removal of the mobile phase, benzamide and dioctyl sebacate were successfully identified from the FTIR spectrum. Surprisingly, the interference from adsorbed water or conventionally used LC solvents in the FTIR spectrum was completely eliminated by using CuO particles as the interface in the off-line hyphenation of LC-FTIR. Based on these results, CuO demonstrates potential as an ideal interface for LC-FTIR analysis.

Properties of 2D asynchronous spectra generated from a series of fluorescence emission spectra are investigated. Variable excitation wavelengths are utilized as an external perturbation. Based on the results of mathematical analysis and computer simulation, we find that no cross peak will be produced on the 2D asynchronous spectrum if the fluorescent solute under investigation occurs in a single micro-environment. The observation of cross peaks implies that the fluorescent molecule may occur in different micro-environments in a solution. Based on these results, we use 2D asynchronous spectra to investigate the emission spectra of anthracene dissolved in cyclohexane. When the concentration of anthracene is low, no cross peak is produced in the resultant 2D asynchronous spectrum, confirming that anthracene is dissolved as single molecule in the solution. As the concentration elevated, cross peaks appear in the corresponding 2D asynchronous spectra. A plausible explanation of this phenomenon is that anthracene may undergo aggregation via π-π interaction or π-C-H interaction.

We propose a substantially simplified approach to construct a pair of 2D asynchronous spectra based on the DAOSD approach proposed in our previous papers. By using a new concentration series, only three 1D spectra are used to generate a pair of 2D correlation spectra together with two reference spectra. By using this method, the previous problem of labor intensive traditional DAOSD approach has been successfully addressed. We apply the new approach to characterize intermolecular interaction between acetonitrile and butanone dissolved in carbon tetrachloride. The existence of intermolecular interaction between the two solutes can be confirmed by the presence of a cross peak in the resultant 2D IR spectra. In addition, the absence of cross peak around (2254, 2292) in Psi(butanone) provides another experimental evidence to reveal the intrinsic relationship between the stretching band and an overtone band (delta(CH3)+v(C-C)). (C) 2016 Elsevier B.V. All rights reserved.

We applied a newly developed technique of the DAOSD (Double Asynchronous Orthogonal Sample Design) approach to probe weak coordination between Co2+ ions and acetone. Subtle spectral variation on the carbonyl band of acetone and d-d transition band are revealed via cross peaks of 2D asynchronous spectra generated by using the DAOSD approach. These results suggest that coordination occur between cobalt ions and the carbonyl group of acetone. To confirm whether coordination occur between cobalt ions and acetone, EXAFS experiments are utilized. The EXAFS results reveal that a Co2+ is coordinated by six methanol molecules in anhydrous COCl2/methanol solution. Upon addition of acetone in into the anhydrous COCl2/methanol solution, the coordination number of Co2+ ion becomes four, and one coordinating oxygen atom is replaced by a chlorine atom. We infer that the decrease in coordination number of Co2+ ion is due to the participation of the carbonyl oxygen of acetone in the coordination since the size of acetone is larger than methanol. This result provides an alternative evidence to support the conclusion that Co2+ ions coordinate with acetone, which is separately obtained from the 2D asynchronous spectra generated by using the DAOSD approach. (C) 2014 Elsevier B.V. All rights reserved.

With the development of new materials and new energy industries, power devices have also made great progress. Compared with traditional silicon-based power electronic devices, wide-band gap semiconductor devices based on silicon carbide which are considered to be an important alternative to silicon-based devices, have excellent properties such as high breakdown voltage, thermal conductivity, and electron saturation drift and radiation resistance. At the same time, power electronic devices are widely used in high-speed railway. The application of a new type of silicon carbide power device in electrical traction is discussed. The experiment of system characteristics shows that the power device made of silicon carbide can effectively reduce the power loss of the system, adapt to the bad working conditions, and make the equipment lightweight.

We applied TLC/FTIR coupled with a mapping technique to analyze a cholesterol/benzamide mixture. Narrow-band TLC plates by using AgI as a stationary phase were used to separate benzamide and cholesterol. The distribution of cholesterol and benzamide spots was manifested by 3D chromatogram. Benzamide and cholesterol can be successfully separated by the narrow-band TLC plate. Moreover, characteristic bands of benzamide and cholesterol can be identified from their FTIR spectra. In addition, the FTIR spectra of the separated benzamide and cholesterol spots on the narrow band TLC plate are roughly the same as the corresponding reference IR spectra.

We report the discovery of a potentially useful superconcentrated HCl at ambient temperature and pressure by using a simple surfactant-based reversed micelle system. Surprisingly, the molar ratios of H(+) to H(2)O (denoted as n(H+)/n(H2O)) in superconcentrated HCl can be larger than 5, while the maximum achievable n(H+)/n(H2O) value for conventional saturated HCl aqueous solution (37 wt %) is only about 0.28. Furthermore, both NMR and FT-IR results indicate that a significant amount of HCl remains in the molecular form rather than being ionized into H(+) and Cl(-). The superconcentrated HCl may promote some organic reactions that are not feasible by using conventional 37 wt % HCl solution. For example, addition reaction between C═C and HCl occurs in superconcentrated HCl solution without using catalysts.

Hydrogen sulfide (H2S) plays a crucial role in the regulation of blood pressure and oxidative stress. In the present study, we tested the hypothesis that H2S exerts its cardiovascular effects by reducing oxidative stress via inhibition of NADPH oxidase activity in the rostral ventrolateral medulla (RVLM). We examined cell distributions of cystathionine-β-synthase (CBS) and effects of H2S on reactive oxygen species (ROS) and mean arterial blood pressure (MAP) in spontaneously hypertensive rats (SHRs). We found that CBS was expressed in neurons of the RVLM, and the expression was lower in SHRs than in Wistar-Kyoto rats. Microinjection of NaHS (H2S donor), S-adenosyl-l-methionine (SAM, a CBS agonist), or Apocynin (NADPH oxidase inhibitor) into the RVLM reduced the ROS level, NADPH oxidase activity, and MAP, whereas microinjection of hydroxylamine hydrochloride (HA, a CBS inhibitor) increased MAP. Furthermore, intracerebroventricular infusion of NaHS inhibited phosphorylation ofp47phox, a key step of NADPH oxidase activation. Since decreasing ROS level in the RVLM reduces MAP and heart rate and increasing H2S reduces ROS production, we conclude that H2S exerts an antihypertensive effect via suppressing ROS production. H2S, as an antioxidant, may be a potential target for cardiovascular diseases.

We report a new super-concentrated HCl system prepared by using trioctylphosphine oxide (TOPO)-based reverse micelles. The observed molar ratio between acid and water (n(HCl)/n(H2O)) in the super-concentrated HCl are much higher than that in the saturated aqueous HCl solution (0.28). Moreover, FT-IR spectroscopic results reveal that a significant amount of HCI remains in the molecular form rather than being ionized into H+ and Cl-. As a result, two H-Cl stretching bands can be observed in the FT-IR spectrum, The super-concentrated HCI provides a unique chemical environment in which many chemical substances occur in unusual states. For example, the color of super-concentrated HCl solution containing copper ion was found to be reddish brown rather than green as in conventional state. UV-Vis-NIR spectral results indicate that both d-d transition band of Cu2+ and charge transfer band of Cl-Cu in super-concentrated HCl underwent significant variation. Additionally, copper ions bring about remarkable variation on the hydrogen bond network among HCI in the super-concentrated HCI solution as demonstrated by FT-IR spectra. According to the EXAFS results, we suggest that copper ion may occur as HCuCl3 in the super-concentrated HCl. (C) 2014 Elsevier B.V. All rights reserved.

We have recently demonstrated that the second hyperpolarizability γ of a selected vibrational mode of a molecule can be determined by using the computational Raman activity against an internal standard with a known Raman γ value. This approach provides a convenient way for prediction of the γ magnitude of DOVE four wave mixing spectroscopy, an optical analogue to two-dimensional (2D) NMR. Here, by using the Hartree-Fock (HF) method, the density functional theory (DFT) method, and the second-order Møller-Plesset perturbation theory (MP2) method, we extend our early work from the less anharmonic region2000 cm(-1) into the more anharmonic region2000 cm(-1) covering C-H, C-D, and C≡N stretching modes of benzene, deuterated benzene, acetonitrile, deuterated acetonitrile, and tetrahydrofuran. The computed Raman γ values of these vibrational modes have been determined by using either the 992 cm(-1) Raman band of benzene or the compound's own Raman band (C-C stretch) around 800-1000 cm(-1) as an internal standard. In this more anharmonic region, the HF method with a larger basis set provides the best outputs and the predicted Raman γ values agree well with experimental values for most of the vibrational modes studied. By choosing a suitable method and basis set, this facile approach could be applied to a broader spectral range for Raman γ estimation of various materials.