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The phasor approach to fluorescence lifetime imaging microscopy (FLIM) is used to identify different types of tissues from hematoxylin and eosin (H&E) stained basal cell carcinoma (BCC) sections. The results suggest that working directly on the phasor space with the clustering assignment achieves immunofluorescence like simultaneous five or six-color imaging by using multiplexed fluorescence lifetimes of H&E. The phase approach is of particular effectiveness for enhanced visualization of the abnormal morphology of a suspected nidus. Moreover, the phasor approach to H&E FLIM data can determine the actual paths or the infiltrating trajectories of basophils and immune cells associated with the preneoplastic or neoplastic skin lesions. The integration of the phasor approach with routine histology proved its available value for skin cancer prevention and early detection. We therefore believe that the phasor analysis of H&E tissue sections is an enhanced visualization tool with the potential to simplify the preparation process of special staining and serve as color contrast aided imaging in clinical pathological examination. [ABSTRACT FROM AUTHOR]

A scalable and facile solid-catalyzed growth approach is reported to integrate N-doped carbon tentacles with metal selenide nanoparticles, showing great potential for mass production of non-precious metal catalysts for rechargeable Zn–air batteries. [ABSTRACT FROM AUTHOR]

Melanoma is known to be radioresistant and traditional treatments have been intractable, and therefore, novel approaches are required to improve therapeutic efficacy. Gold nanoparticles (GNPs) have been explored as radiosensitizers, while most of the research in the area has focused on the enhancement occurred in the kilovoltage (kV ) range. The present study investigated the possible application and biological mechanism of gold nanorods (GNRs) for sensitization at clinically relevant MV X-ray energies. A375 melanoma cells were treated by gold nanorods (GNRs) with or without irradiation. The anti-proliferative impacts of the treatments were measured by MTT assay. The cellular uptake and intracellular localization were analyzed by transmission electron microscopy. Radiosensitizing effects were determined by a colony formation assay. Apoptosis and cell cycle data were measured by flow cytometry. DNA damage was estimated by γ-H2AX expression measured with immunofluorescent staining. Results showed that the addition of GNRs enhanced the radiosensitivity of A375 cells with a dose-modifying factor (DMFSF2) of 1.14, increasing more radiation-induced DNA double-strand breaks and apoptosis. DNA flow cytometric analysis indicated that GNRs plus irradiation significantly induced G2/M phase arrest in A375 cells. In Conclusions: GNRs could sensitize melanoma A375 cells to 6 MV X-ray irradiation, and this was mainly through increasing the DNA doublestrand breaks, in addition to the induction of a higher proportion of cells within the G2/M phase. The interaction of GNRs and high energy commonly used in the clinic may provides another rational for the potential application of GNRs in the treatment of cancer. [ABSTRACT FROM AUTHOR]

Maskless phase-change lithographic technology is developed as a photoresist of phase-change materials. The controllable growth behavior of the crystallization region on an amorphous thin film of Ge2Sb2Te5 (GST) irradiated by a laser beam is investigated; the GST thin film is deposited on a silicon substrate by the sputtering method. The results of a series of the experiments and the simulations all show that the width of a crystalline pattern is not only closely related to laser power and pulse duration, but also is apparently affected by the interactive area between the focused laser spot and thin film. The width maintains a nonlinear growth with the enhancement of the laser power until the thin film approaches melting, whereas it gradually reaches a constant value due to the local thermal equilibrium. This equilibrium makes the width irrelevant to the moving velocity with certain constraints when the laser works in continuous-wave mode. Within a defocus range of 15 µm, the widths of the crystalline patterns are obtained in a broad range from 690 nm to 8.13 µm under a 0.4-NA objective lens. By adjusting the defocus amount, some crystalline square patterns with expected widths in a wide range are fabricated, and the mean percentage error between the expected and fabricated widths is only 1.495%. [ABSTRACT FROM AUTHOR]

Ischemia and reperfusion (IR) injury constitutes a pivotal mechanism of tissue damage in pathological conditions such as stroke, myocardial infarction, vascular surgery, and organ transplant. Imaging or monitoring of the change of an organ at a molecular level in real time during IR is essential to improve our understanding of the underlying pathophysiology and to guide therapeutic strategies. Herein, we report molecular imaging of a rat model of hepatic IR with the autofluorescence of mitochondrial flavins. We demonstrate a revelation of the histological characteristics of a liver in vivo with no exogenous stain and show that intravital autofluor-escent images exhibited a distinctive spatiotemporal variation during IR. The autofluorescence decayed rapidly from the baseline immediately after 20-min ischemia (approximately 30% decrease in 5 min) but recovered gradually during reperfusion (to approximately 99% of the baseline 9 min after the onset of reperfusion). The autofluorescent images acquired during reperfusion correlated strongly with the reperfused blood flow. We show further that the autofluorescence was produced predominantly from mitochondria, and the distinctive autofluorescent variation during IR was mechanically linked to the altered balance between the flavins in the oxidized and reduced forms residing in the mitochondrial electron-transport chain. Our approach opens an unprecedented route to interrogate the deoxygenation and reoxygenation of mitochondria, the machinery central to the pathophysiology of IR injury, with great molecular specificity and spatiotemporal resolution and can be prospectively translated into a medical device capable of molecular imaging. We envisage that the realization thereof should shed new light on clinical diagnostics and therapeutic interventions targeting IR injuries of not only the liver but also other vital organs including the brain and heart. [ABSTRACT FROM AUTHOR]

A novel hydrothermal dephosphorylation route for the synthesis of ultrasmall nucleotide-coated superparamagnetic γ-Fe2O3nanoparticles (∼5 nm) has been demonstrated. The synthesized γ-Fe2O3nanoparticles show excellent thermal stability, water dispersion and biocompatibility, allowing possible applications for in vivoX-ray contrast agents. [ABSTRACT FROM AUTHOR]

Because of frequent exposure to carcinogens, the bronchus is prone to early pathologic alterations. The assessment of these early changes is of key significance in physiological studies and disease diagnosis of the bronchus. We utilize nonlinear optical microscopy (NLOM) to image mouse bronchial tissue based on intrinsic nonlinear optical contrast. Our results show that NLOM is effective for imaging the bronchial intact microstructural components, providing quantitative information about the biomorphology and biochemistry of tissue. Our findings also display that NLOM can provide a two-photon ratiometric redox fluorometry, based on mitochondrial signals and reduced pyridine nucleotide (NADH and NADPH) and oxidized flavoproteins (Fp) signals, to assess the metabolic state of the epithelial cells and chondrocytes. It was found that NLOM can offer a sensitive tool, based on the second-harmonic signal depth-dependent decay, to obtain quantitative information on the optical property of the stroma associated with normal and diseased tissue states. Our results suggest that with the advent of the clinical portability of typical nonlinear optical endoscopy, the NLOM technique has the potential to be applied in vivo to the clinical diagnosis and monitoring of bronchial disease. [ABSTRACT FROM AUTHOR]