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Zhao Q.L.,Institute of Laser Life Science | Guo Z.Y.,Institute of Laser Life Science | Si J.L.,Guangzhou University | Wei H.J.,Institute of Laser Life Science | And 7 more authors.
Laser Physics | Year: 2011

The main objective of the present work is to study the influence of heat treatment on the esophageal cancer detection using the diffuse reflectance (DR) spectral intensity ratio R540/R575 of oxygenated hemoglobin (HbO2) absorption bands to distinguish the epithelial tissues of normal human esophagus and moderately differentiated esophageal squamous cell carcinoma (ESCC) at different heat treatment temperature of 20, 37, 42, 50, and 60°C, respectively. The DR spectra for the epithelial tissues of the normal esophagus and ESCC in vitro at different heat-treatment temperature in the wavelength range 400-650 nm were measured with a commercial optical fiber spectrometer. The results indicate that the average DR spectral intensity overall enhancement with concomitant increase of heat-treatment temperature for the epithelial tissues of normal esophagus and ESCC, but the average DR spectral intensity for the normal esophageal epithelial tissues is relatively higher than that for ESCC epithelial tissues at the same heat-treatment temperature. The mean R540/R575 ratios of ESCC epithelial tissues were always lower than that of normal esophageal epithelial tissues at the same temperature, and the mean R540/R575 ratios of the epithelial tissues of the normal esophagus and ESCC were decreasing with the increase of different heat-treatment temperatures. The differences in the mean R540/R575 ratios between the epithelial tissues of normal esophagus and ESCC were 13.33, 13.59, 11.76, and 11.11% at different heat-treatment temperature of 20, 37, 42, and 50°C, respectively. These results also indicate that the DR intensity ratio R540/R575 of the hemoglobin bands is a useful tool for discrimination between the epithelial tissues of normal esophagus and ESCC in the temperature range from room temperature to 50°C, but it was non-effective at 60°C or over 60°C. © 2011 Pleiades Publishing, Ltd.


Zheng J.,South China Normal University | Xing X.,South China Normal University | Xing X.,Institute of Laser Life Science | Evans J.,Zhejiang University | And 3 more authors.
NPG Asia Materials | Year: 2016

Manipulating large numbers of a variety of particles/wires is essential for many lab-on-a-chip technologies. Here we generate a planar array of optofluidic vortices with photothermal gradients from an easy-fabricated graphene oxide (GO) heater to achieve high-throughput and multiform manipulation at low excitation power and low loss. As a tweezer, each vortex can rapidly capture and confine particles without restrictions on shapes and materials. The stiffness of the confinement is easily tuned by adjusting the vortex dimension. As a motor, it can actuate any traps to persistently rotate/spin in clockwise or anti-clockwise mode. As a high-performance 'workshop', this work lays the groundwork for various self-assembly ranging from colloid-based clusters, chains, capsules, shells and ultra-thin films, through particles' surface modification and fusion, to nanowire-based architectures. Furthermore, we can create multiple vortex arrays through fabricating an array of heaters, which enables massively parallel manipulation and distributed operations all on a chip.


Xing X.,Institute of Laser Life Science | Xing X.,Jinan University | Li B.,Sun Yat Sen University
Advanced Materials Research | Year: 2011

Based on a finite difference method, terahertz (THz) confinement and dispersion in Si-based subwavelength slot waveguide has been investigated. The field of TE mode can be confined in an air slot (4 μm-wide) because of large discontinuity of electric field at high-index-contrast interfaces. Performance of the slot waveguide operating at a wavelength of λ = 165 μm (1.82 THz) has been analyzed. Normalized power in the air slot can reach 78%. It also exhibits weak wavelength dependence and large structure tolerance on the power confinement. Moreover, influence of group velocity dispersion (GVD) on reshaping of transmitted ps pulses has been analyzed, showing the slot waveguides with low GVD. © (2011) Trans Tech Publications.


Mi Y.-J.,Xiamen University | Geng G.-J.,Xiamen University | Zou Z.-Z.,Institute of Laser Life Science | Gao J.,Xiamen University | And 7 more authors.
PLoS ONE | Year: 2015

Despite recent advances in the therapy of non-small cell lung cancer (NSCLC), the chemotherapy efficacy against NSCLC is still unsatisfactory. Previous studies show the herbal antimalarial drug dihydroartemisinin (DHA) displays cytotoxic to multiple human tumors. Here, we showed that DHA decreased cell viability and colony formation, induced apoptosis in A549 and PC-9 cells. Additionally, we first revealed DHA inhibited glucose uptake in NSCLC cells. Moreover, glycolytic metabolism was attenuated by DHA, including inhibition of ATP and lactate production. Consequently, we demonstrated that the phosphorylated forms of both S6 ribosomal protein and mechanistic target of rapamycin (mTOR), and GLUT1 levels were abrogated by DHA treatment in NSCLC cells. Furthermore, the upregulation of mTOR activation by high expressed Rheb increased the level of glycolytic metabolism and cell viability inhibited by DHA. These results suggested that DHA-suppressed glycolytic metabolism might be associated with mTOR activation and GLUT1 expression. Besides, we showed GLUT1 overexpression significantly attenuated DHA-triggered NSCLC cells apoptosis. Notably, DHA synergized with 2-Deoxy-D-glucose (2DG, a glycolysis inhibitor) to reduce cell viability and increase cell apoptosis in A549 and PC-9 cells. However, the combination of the two compounds displayed minimal toxicity to WI-38 cells, a normal lung fibroblast cell line. More importantly, 2DG synergistically potentiated DHA-induced activation of caspase-9, -8 and -3, as well as the levels of both cytochrome c and AIF of cytoplasm. However, 2DG failed to increase the reactive oxygen species (ROS) levels elicited by DHA. Overall, the data shown above indicated DHA plus 2DG induced apoptosis was involved in both extrinsic and intrinsic apoptosis pathways in NSCLC cells. © 2015 Mi et al.


Hu J.,Shantou University | Yu M.,Shantou University | Ye F.,Institute of Laser Life Science | Da X.,Institute of Laser Life Science
Journal of Biomedical Optics | Year: 2011

Osteosarcoma is one of the most common primary malignant tumors of the bone and the second leading cause of cancer-related deaths in the pediatric age group. Confirmed diagnosis and prompt treatment of osteosarcoma are critical for effective prognosis. In this study, we investigate the application of photoacoustic imaging (PAI) for the detection of osteosarcoma in an animal model. Crosssection images of a normal rat leg and a tumorous rat leg were successfully reconstructed in vivo. Morphological changes and the development of the implanted osteosarcoma were accurately mapped with time-dependent photoacoustic images. Furthermore, we evaluate the use of gold nanorods as contrast agents for imaging osteosarcoma with PAI. This is the first study that uses PAI to detect osteosarcoma in vivo, and the results suggest that PAI has the potential clinical application for detecting osteosarcoma in the early stage. © 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).


Zhou J.,Institute of Laser Life Science | Sun A.,Institute of Laser Life Science | Xing D.,Institute of Laser Life Science
Journal of Experimental Botany | Year: 2013

Sclerotinia sclerotiorum can initially suppress host oxidative burst to aid infection establishment, but later promotes reactive oxygen species (ROS) generation as proliferation advances. Here, it was shown that the cellular redox status can be modulated by thiamine to protect Arabidopsis thaliana against Sclerotinia at the early stages of infection. The initial inhibition of host ROS generation by Sclerotinia-secreted oxalate could effectively be alleviated by thiamine. Thiamine pre-treatment and subsequent wild-type Sclerotinia invasion induced an increase of ascorbate peroxidase activity concomitant with decreased ascorbate/dehydroascorbate ratios, which led to the cellular transition towards oxidative status in infected tissues. Particularly, it was observed that wild-type Sclerotinia, but not oxalate-deficient A2 mutant, could suppress the activity of NADPH oxidase (NOX), which might be an important mechanism underlying the early inhibition of ROS burst. Nevertheless, thiamine pre-treatment followed by wild-type Sclerotinia infection promoted NOX-derived ROS accumulation. Further studies showed that cytosolic Ca2+ and staurosporine-sensitive protein kinase(s) participated in thiamine-induced activation of NOX. Moreover, thiamine-induced tissue defence responses including callose/lignin deposition and stomatal closure were closely correlated with NOX-derived ROS generation. Additionally, studies with Brassica species indicated that the regulation of thiamine is largely conserved upon Sclerotinia infection. Collectively, it was concluded that thiamine reverses the initial reducing status through activating NOX-dependent ROS signalling to perturb the disease progress of Sclerotinia. © The Author [2013].


Li X.L.,Institute of Laser Life Science
Applied Surface Science | Year: 2010

A quantitative thermodynamic model addressing the stability and evolution mechanism during growth process of quantum dots (QDs) in Stranski-Krastanow (SK) system is established by taking into account the thickness-dependent surface energy of wetting layer (WL). It is found that the thickness-dependent surface energy of WL prevents QDs from growing up without limit. The competition between relaxation energy of QDs and thickness-dependent surface energy of WL results in a puzzling phenomenon that WL not only can hardly capture atoms to grow, but also need release atoms into QDs during deposition process and annealing. Agreement between theoretical results and experiments implies that the established thermodynamic model could be expected to be a general approach to pursue the physical mechanisms of self-assembly of quantum dots. © 2010 Elsevier B.V. All rights reserved.


Li X.L.,Institute of Laser Life Science
Journal of Physical Chemistry C | Year: 2010

We have developed a theoretical model to elucidate the formation mechanisms of multiple concentric nanoring structures upon droplet epitaxy. On the basis of the developed model, we performed the shape evolution of GaAs nanostructures during the multistep crystallization process. Theoretical analyses indicated the rapid growth region at the periphery of the diffusion region is pushed outward by increasing growth temperature, which results in the formation of an outer ring. In addition, according to our model, we proposed that multiple concentric nanoring structures can also be obtained via reducing element flux intensity using a multistep crystallization procedure which may be more advantageous than that via increasing temperature. © 2010 American Chemical Society.


Yang Y.,Institute of Laser Life Science | Xing D.,Institute of Laser Life Science | Zhou F.,Institute of Laser Life Science | Chen Q.,Institute of Laser Life Science
Biochemical and Biophysical Research Communications | Year: 2010

Autophagy is an evolutionarily conserved process for bulk degradation of cytoplasmic components, including large molecules and organelles. It can either help to enhance or to resist apoptosis, depending on the circumstances. The mechanism of how autophagy impacts apoptosis and the subsequent cellular events upon heat shock remains unclear. In this study, we demonstrate for the first time that mitochondrial membrane permeability transition (MPT)-sensitive mitochondrial autophagy can protect against heat-induced apoptosis through reduction of cytosolic cytochrome c release and downstream caspase-3 activation. With confocal microscopy, it was revealed that as autophagosomes increased, mitochondrial content was mass decreased after heat shock. Detailed analysis shows that a single swelling mitochondrion could be entrapped into autophagosome. The depolarization of mitochondria preceded the mitochondrial loss, and both could be abolished by MPT inhibitor cyclosporine (CsA). In addition, along with the decrease of mitochondrial content, the level of total cytochrome c was also reduced, resulting in a reduction of its release to cytoplasm. When heat shock was combined with 3-methyladenine (3-MA), an inhibitor of autophagy, the mitochondrial loss and the reduction of total cytochrome c were both inhibited, and then caspase-3 activation and cell apoptosis were increased. Thus, it is reasonable to believe that, heat shock-induced cellular events can be modulated by controlling autophagy, and this may represent a novel approach to enhance the efficacy of hyperthermia. © 2010 Elsevier Inc. All rights reserved.

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