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Abstract: ZnO whiskers and Sb2O3 co-modified lead zirconate titanate (denoted as PZT/ZnO w /Sb2O3) piezoelectric composites were fabricated using a solid state sintering technique. The characteristic diffraction peaks of the PZT perovskite and ZnO phases were identified from all the composites, suggesting the retention of these individual phases. The grain size of PZT was found to be reduced with Sb2O3 addition. A high relative density of 96.5%–99.1% was achieved in PZT co-doped with ZnO w and Sb2O3. Both the piezoelectric and mechanical properties of the PZT/ZnO w /Sb2O3 composites showed significant improvement over the monolithic PZT. The intrinsic effects of ZnO w and Sb2O3 on the electrical and mechanical properties of the PZT/ZnO w /Sb2O3 composites were discussed. [Copyright &y& Elsevier]

Objective: To observe the effect of electroacupuncture (EA) and moxibustion (Moxi) pretreatment on expression of myocardial heat shock protein (HSP) in acute myocardial ischemia-reperfusion injury (MIRI) rabbits., Methods: A total of 72 New Zealand rabbits were randomly divided into 4 groups:sham operation, MIRI model, EA pretreatment and Moxi pretreatment ( n =18 rabbits in each group) which were further divided into 0, 24 and 48 h (time-point) subgroups ( n =6 in each). The MIRI model was established by occlusion of the anterior descending branch (ADB) of the left coronary artery for 40 min and reperfusion for 60 min. EA and Moxi stimulation was respectively applied to bilateral "Neiguan"(PC 6) for 20 min, once daily for 5 days before ADB occlusion. The expressions of myocardial HSP 27, HSP 70 and HSP 90 were detected by immunohistochemistry. The pathological and ultrastructural changes of left ventricular ischemia tissue were observed under light and transmission electronic microscope (TEM), respectively., Results: Outcomes of H.E. staining and ultrastructure showed that MIRI-induced changes of disordered arrangement of cardiomyocytes, vague myocardial transverse striation, inflammatory infiltration, cardiac myofibre necrosis and fibrolysis (light microscope), and myofiber atrophy, vague and disorder in the arrangement of myofiber, myofilament necrosis, interstitial edema, mitochondrial swelling, microvessel expansion, etc. (TEM) were relatively milder in both EA and Moxi pretreatment groups (48 h). In comparison with the sham group, the expression levels of myocardial HSP 27, HSP 70 and HSP 90 had no significant changes after MIRI at the 3 time-points ( P >0.05). In the pretreatment groups, the expression levels of HSP 27 at 24 and 48 h in both EA and Moxi groups, HSP 70 at 48 h in both groups, HSP 70 at 0 and 24 h in the Moxi group were significantly up-regulated compared with the model group ( P <0.05, P <0.01). No significant changes were found in the expression of HSP 90 at the 3 time-points in the EA and Moxi pretreatment groups ( P >0.05). No significant differences were found between EA and Moxi in up-regulating expressions of myocardial HSP 27, HSP 70 and HSP 90 proteins at the 3 time-points ( P >0.05) except HSP 70 at 24 h (Moxi being stronger relative to EA, P <0.05)., Conclusions: EA and Moxi pretreatment has a protective effect on ischemic myocardium in MIRI rabbits, which Feb be associated with their actions in up-regulating myocardial HSP 27 and HSP 70 expression.

In the present paper electroluminescence spectrum and Raman spectrum were used to study electro-degradation of polymer light emitting devices (PLEDs) of PFO-BT15, a new and high-efficiency emitting polymer synthesized by the institute of polymer optoelectronic material & devices (IPOM) in South China University of Technology. The PLEDs with a configuration of ITO glass/PEDOT(120 nm)/PFO-BT15(80 nm)/Ba(4 nm)/Al(200 nm) emitted green light at 550 nm when 5 V dc voltage was applied. Three of those devices were used to study the electro-degradation mechanism of PLEDs. Device A was deposited in vacuum box in dark room to keep sample fresh; Device B was first lighted with current of 1 mA x 0.25 cm(-2) for 200 minutes, then with current of 5 mA x 0.25 cm(-2) for 60 minutes, finally with current of 10 mA x 0.25 cm(-2) for 40 minutes; Device C was lighted with current of 20 mA x 0.25 cm(-2) until the electroluminescence failure. Our experimental results indicate that the degradation speeds highly depend on the current through the devices. The stressed devices show the decrease in electroluminescence efficiency. However, the luminescence spectrum of the stressed device did not change compared with the fresh device, which suggest that the structure of the luminescent polymer did not change with the electro-stress. Raman spectrum was employed to probe the structure changes of the materials used in the device. We found that the PEDOT Raman peak disappeared andthe PFO-BT15 Raman peak still existed in electro-stress device. The results confirmed that it was the breakage of the PEDOT layer instead of degradation of emitting polymer, that led to the final failure of the PLEDs device. This work gives some valuable information for the design and development of highly stable organic light-emitting device.

Poly (3,4-ethylene dioxythiophene) (PEDOT): Poly (styrene sulfonate) (PSS) has attracted a lot of interest for application in organic electronics due to good stability and high electronic conductivity in its doped state. Indeed, thin layers of PEDOT:PSS was regularly used in light emitting diodes (PLEDs) as hole injection and transportation layer. Here, Doping and dedoping states of PEDOT:PSS were studied by absorbance spectra and Raman spectra. A new absorption band centered at 620 nm was observed on dedoped PEDOT:PSS. Consistently, Raman signals of dedoped PEDOT:PSS are resonantly intensified since the Raman excitation wavelength (633 nm) is set in the enhanced absorption band. So it gives a sensitive way to study the doping and dedoping states of PEDOT:PSS. Furthermore, for the encapsulated polymer light-emitting diodes, Raman spectroscopy is a powerful way to study the polymer layers inside the devices.

Unlabelled: To further explore the relationship between hypertrophic scar and injury to conical structure of skin and the pathogenesis of hypertrophic scar, and to reproduce an optimal animal model of hypertrophic scar., Methods: The back of two FRDP pigs were shaved, and a piece of normal skin was harvested for the observation of conical structure of skin. Skin wounds with depth of 0.38 mm, 0.76 mm, 1.14 mm and 1.52 mm, respectively, were created by gas-driven dermatome. Eight wounds measuring 7.0 cm x 7.0 cm were created on each pig. The wounds were divided into 4 groups according to the wound depth with 4 wounds in each group, i.e. 0.38 mm group, 0.76 mm group, 1.14 mm group and 1.52 mm group. The 0.38 mm and 0.76 mm groups were designated as superficial wound groups and 1.14 mm and 1.52 mm groups as deep wound groups. The wounds were allowed to heal without treatment. Tissue samples from the wound were harvested on 0, 10, 30, 60, 90 and 150 post injury day (PID) , and they were sectioned for HE staining and staining for elastic fibers (VVG). The wound healing and the scar formation were observed with naked eye. The skin conical structures in normal and injured skin were also observed. The morphology of hypertrophic scar was observed, and the thickness of the scar tissue was determined and scored., Results: The wounds in superficial wound groups healed within 3 weeks with flat surface without scar formation. The wounds in deep wound groups healed later than 4 weeks with thick, hairless, hard in texture, with depigmentation or pigmentation, finally forming contracture. The skin conical structure could be found on the back of FRDP with HE and VVG staining, and it was similar to that of human in terms of the structure. In superficial wound groups, the upper part of the skin conical structure was injured, but fat fornix and glands were intact. In deep wound groups, the lower part of the skin cone, together with the fat fornix and gland were all injured. On the 150th post injury day, the histological picture of the tissue in superficial wound groups was similar to that of normal skin. But the skin conical structure could not be found in deep wound groups, and the wounds were filled by a large accumulation of disarrayed and irregularly arranged collagen fibers. With passage of time, the scar became thicker and thicker, and the scar hypertrophy reached the zenith in 150th PID., Conclusion: The injury of skin conical structure can lead to the formation of hypertrophic scar. FRDP can be used to reproduce and ideal model of hypertrophic scar.

Depth analysis of confocal Raman micro-spectroscopy was applied to chirography identification. The result indicated that depth analysis has potential application to forensic science field, especially in longitudinal identification of ink and inkpad. No matter what the spatial distributions of the signature pen and inkpad are, confocal Raman micro-spectroscopy can longitudinally distinguish those spatial differences. All those suggested that confocal Raman micro-spectroscopy is a fast, simple, high sensitive and non-destructive technique.

The authors report Raman degradation study of polymer light-emitting devices under ambient conditions. In order to investigate the chemical degradation reaction in polymer light-emitting diode (PLEDs) devices, the chemical structure of the poly (2-(4-Ethylhexyl) phenyl-1, 4-phenylene vinylene) (P-PPV) polymer was analyzed by micro-Raman spectroscopy during the lifetime of the devices. The evidence for the reduction of conjugation length is provided by Raman spectroscopy. This reduction of theconjugation length, which dramatically increases the resistance and cuts off the current density, was the main reason for the failure of lighting. These findings provide an important insight into the intrinsic degradation mechanisms of the polymer LEDs and help in the development of even more stable devices.

In the present work we have designed a small-size portable imaging spectrometer using linear variable interference filter, with CCD camera as picture sensor, and micromotion stage to bring along interference filter which scan across every pixel of CCD array. The difference column pixel in the picture which we get at every step is monocolour partial image under different wavelength, with the step by step, these column monocolour pixels change the wavelength. And finally we reassembled these images and get the whole monocolour image with different wavelength. The interval of sweep step length decided by the required spectrum resolution and the required wavelength interval of different pictures. The experiment demonstrated the resolution of this spectrometer is about 16 nm, but that major reason of the limiting resolution is the band width of the linear variable interference filter. The spatial resolution of the instrument ultimately decided by CCD, filter and imaging lens. This spectrometer has some characters such as compact structure, higher spatial resolution, higher spectrum resolution, higher scan rate and so on. Furthermore, an application of this instrument in distinguishing from camouflage have been showed.