Cherenkov Excited Short-Wavelength Infrared Fluorescence Imaging in vivo with External Beam Radiation

Cherenkov emission induced by external beam radiation therapy from a clinical linear accelerator (LINAC) can be used to excite phosphors deep in biological tissues. As with all luminescence imaging, there is a desire to minimize the spectral overlap between the excitation light and emission wavelengths, here between the Cherenkov and the phosphor. Cherenkov excited short-wavelength infrared (SWIR, 1000 to 1700 nm) fluorescence imaging has been demonstrated for the first time, using long Stokes-shift fluorophore PdSe quantum dots (QD) with nanosecond lifetime and an optimized SWIR detection. The 1  /  λ2 intensity spectrum characteristic of Cherenkov emission leads to low overlap of this into the fluorescence spectrum of PdSe QDs in the SWIR range. Additionally, using a SWIR camera itself inherently ignores the stronger Cherenkov emission wavelengths dominant across the visible spectrum. The SWIR luminescence was shown to extend the depth sensitivity of Cherenkov imaging, which could be used for applications in radiotherapy sensing and imaging in human tissue with targeted molecular probes

Effect of Myostatin Depletion on Weight Gain, Hyperglycemia, and Hepatic Steatosis during Five Months of High-Fat Feeding in Mice

The marked hypermuscularity in mice with constitutive myostatin deficiency reduces fat accumulation and hyperglycemia induced by high-fat feeding, but it is unclear whether the smaller increase in muscle mass caused by postdevelopmental loss of myostatin activity has beneficial metabolic effects during high-fat feeding. We therefore examined how postdevelopmental myostatin knockout influenced effects of high-fat feeding. Male mice with ubiquitous expression of tamoxifen-inducible Cre recombinase were fed tamoxifen for 2 weeks at 4 months of age. This depleted myostatin in mice with floxed myostatin genes, but not in control mice with normal myostatin genes. Some mice were fed a high-fat diet (60% of energy) for 22 weeks, starting 2 weeks after cessation of tamoxifen feeding. Myostatin depletion increased skeletal muscle mass ∼30%. Hypermuscular mice had ∼50% less weight gain than control mice over the first 8 weeks of high-fat feeding. During the subsequent 3 months of high-fat feeding, additional weight gain was similar in control and myostatin-deficient mice. After 5 months of high-fat feeding, the mass of epididymal and retroperitoneal fat pads was similar in control and myostatin-deficient mice even though myostatin depletion reduced the weight gain attributable to the high-fat diet (mean weight with high-fat diet minus mean weight with low-fat diet: 19.9 g in control mice, 14.1 g in myostatin-deficient mice). Myostatin depletion did not alter fasting blood glucose levels after 3 or 5 months of high-fat feeding, but reduced glucose levels measured 90 min after intraperitoneal glucose injection. Myostatin depletion also attenuated hepatic steatosis and accumulation of fat in muscle tissue. We conclude that blocking myostatin signaling after maturity can attenuate some of the adverse effects of a high-fat diet

Locational Dynamics of Luxury Hotels in Shanghai Metropolis, China: A Spatial-Temporal Perspective

This study aims to investigate the spatial associations of luxury hotels by using geographical information system (GIS) tools and the multiscale geographically weighted regression (MGWR) model to examine the relationships between the distribution of luxury hotels and exogenous (regional) determinants of urban subdistricts in which the luxury hotels are located. Shanghai City is used as an example. The study first introduces the spatial-temporal characteristics of luxury hotels in Shanghai City, and the key exogenous determinants that contribute to luxury hotel location choice are identified with the MGWR model. The nearest neighbor index decreased from 1.01 to 0.47 and Moran’s I statistics increased from 0.268 to 0.452, revealing that the spatial-temporal evolution pattern of luxury hotels presents a cluster trend from 1995 to 2015. The significance level of the standard regression coefficient shows that the institutional proximity, room rate, green space and the World Expo are the primary determining factors that influence the distribution of luxury hotels in Shanghai City. The analysis is important theoretically, as it presents new and novel methodologies for shedding light on the influencing factors of the locational dynamics of luxury hotels. Meanwhile, it enriches the methodologies for analyzing the relationships between luxury hotels and urban structures, and it is important for practitioners, as it provides strategic information that would enable them to globally select appropriate locations for luxury hotels

Locational Dynamics of Luxury Hotels in Shanghai Metropolis, China: A Spatial-Temporal Perspective

This study aims to investigate the spatial associations of luxury hotels by using geographical information system (GIS) tools and the multiscale geographically weighted regression (MGWR) model to examine the relationships between the distribution of luxury hotels and exogenous (regional) determinants of urban subdistricts in which the luxury hotels are located. Shanghai City is used as an example. The study first introduces the spatial-temporal characteristics of luxury hotels in Shanghai City, and the key exogenous determinants that contribute to luxury hotel location choice are identified with the MGWR model. The nearest neighbor index decreased from 1.01 to 0.47 and Moran’s I statistics increased from 0.268 to 0.452, revealing that the spatial-temporal evolution pattern of luxury hotels presents a cluster trend from 1995 to 2015. The significance level of the standard regression coefficient shows that the institutional proximity, room rate, green space and the World Expo are the primary determining factors that influence the distribution of luxury hotels in Shanghai City. The analysis is important theoretically, as it presents new and novel methodologies for shedding light on the influencing factors of the locational dynamics of luxury hotels. Meanwhile, it enriches the methodologies for analyzing the relationships between luxury hotels and urban structures, and it is important for practitioners, as it provides strategic information that would enable them to globally select appropriate locations for luxury hotels

Study on the microstructure and properties of TiO2/Al composites prepared by FSP

In order to solve the problem of strength and toughness of aluminum matrix composites, TiO2/Al matrix composites were prepared by friction stir processing(FSP). The experiments were carried out by microstructure observation test, tensile test and micro-hardness test to characterize and analyze the strengthening mechanism, microstructure and mechanical properties of composites. The results show that with the introduction of TiO2, the grain has been refined, and the crystalline form of Al is change from continuous dynamic recrystallization(CDRX) of invisible core to the particle-stimulated nucleation mechanism by FSP. The tensile strength and microhardness of the composite are improved. When the addition amount reaches 48%（mass fraction）, the tensile strength is 456 MPa, and the hardness is 130 HV, which increases by 17% and 16%, respectively, compared with that of the unadded particles, and the elongation decreases only by 4%. TiO2 prepared by FSP can effectively improve the mechanical properties and improve the strength and toughness mismatch, which provides theoretical basis and technical reference for the application of new composite materials

Mean (+SEM) muscle and intra-abdominal adipose tissue mass.

<p>Myostatin-deficient (gray bars) and control mice (white bars) were fed a normal low-fat diet (13% of energy from fat) or were fed a high-fat diet (60% of energy from fat) for the final 22 weeks of the experiment. Each bar represents the mean and SEM of 12–15 mice. *<i>P</i><0.001 versus mice with normal myostatin levels.</p

Hepatic steatosis scores and representative micrographs of liver sections.

<p>Distribution of steatosis scores (A) is based on examination of 12 mice with normal myostatin expression and 13 myostatin-deficient mice, all of which received the high-fat diet. Mice fed a low-fat diet did not have hepatic fat accumulation (B, Osmium H&E×250). Mice with normal myostatin expression had significant hepatic steatosis after 5 months of high-fat feeding (C×250; D×500). Larger lipid droplets often lift off the tissue leaving the clear spaces seen in the micrographs. Less fat accumulation was evident in livers of myostatin-deficient mice fed a high-fat diet for 5 months (E×250; F×500).</p

Effects of myostatin depletion and high-fat feeding on body and organ mass.

<p>Values are mean±standard error. Organ mass was determined when mice were 10 months old. Myostatin depletion was induced by tamoxifen feeding for two weeks when mice were 4 months old. High-fat feeding started when mice were 5 months old.</p>a<p><i>P</i><0.02 versus normal myostatin group on same diet.</p>b<p><i>P</i><0.03 versus low-fat diet group with same myostatin status.</p

Mean (±SEM) change in total body mass.

<p>Top panel shows cumulative weight gains after changing dietary fat from 13% to 60% of energy, and lower panel shows biweekly weight changes independent of previous measures. IPGTT = intraperitoneal glucose tolerance test. *<i>P</i><0.05 (adjusted for multiple comparisons) for difference between normal and myostatin-depleted.</p