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ToTEM, a multislice‐based image simulation software is developed for transmission electron microscope (TEM). This software implements the following major features: (i) capability of assigning three‐dimensional potentials of atom into multiple slices and precise introduction of phase shift caused by the sub‐pixel atomic position, (ii) employing CUDA coding and graphical processing units (GPU) with multithreading parallel algorithm based on the powerful batch (inverse) fast Fourier transform (FFT), which is especially beneficial for image simulation of scanning transmission electron microscopy (STEM) or (integrated) differential phase contrast (I)DPC, (iii) design for efficiently generating large batch of data set of high‐resolution transmission electron microscopy (HRTEM) images. Image simulation acceleration for STEM has been verified by simulating a large‐scale SrTiO3. Additionally, iDPC image of MFI‐type zeolites with xylene molecules encapsulated in straight channels demonstrates the advantage of iDPC in detecting light molecules. [ABSTRACT FROM AUTHOR]

Presents a theoretical study of electron transport in the resonant-tunneling diode under the effects of an in-plane magnetic field. Description of the theoretical model; Results; Conclusions.

Objectives To investigate effects of platelet-rich plasma on tendon cell proliferation and the underlying molecular mechanisms. Materials and methods Platelet-rich plasma was prepared manually by two-step centrifugation. Proliferation was evaluated in cultured rat tendon cells by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay. Cell cycle progression was assessed by flow cytometry. Messenger RNA expression of proliferating cell nuclear antigen ( PCNA), cyclin E1, A2 and B1, and cyclin-dependent kinases (Cdks) 1 and 2 was assessed by real-time polymerase chain reaction. Protein expression of the above cyclins and Cdks and of signal transducer and activator of transcription (Stat) 3 and p27 was evaluated by western blotting. Results Platelet-rich plasma used in the present study had concentrations of platelets, TGF-β1 and PDGF over 3-fold higher than normal whole blood. Platelet-rich plasma enhanced tendon cell proliferation ( P = 0.008) by promoting G1/S phase transition in the cell cycle, and increased expression of PCNA, cyclin E1, A2 and B1, Cdks1 and 2, and phosphorylated Stat3, while inhibiting p27 expression. Conclusions Platelet-rich plasma contains high concentrations of TGF-β1 and PDGF that increase tendon cell proliferation by modulating Stat3/p27Kip1, which enhances expression of cyclin-Cdk complexes that promote cell cycle progression. These results provide molecular evidence for positive effects of platelet-rich plasma on tendon cell proliferation, which can be useful in clinical applications of tendon injury. [ABSTRACT FROM AUTHOR]

The erratic p-type conductivity in nitrogen-doped ZnO film is still under investigation and has been debated up to now. In this study, the authors have studied the effect of rapid thermal process (RTP) on the properties of N-doped ZnO films grown by metal-organic chemical vapor deposition. Hall-effect measurements show that the sample is of p-type as the RTP temperature is lower than 350 °C while, as the RTP temperature increased up to 550 °C or higher, the conduction-type of the sample changed to be n-type. Correspondingly, obvious D and G peaks, which are related to graphite clusters, are observed to increase their intensity with RTP temperature, indicating that interstitial or substitutional carbon atoms may migrate to form carbon clusters in the grain boundary during RTP. RTP is also found to lead to significant changes on the photoluminescence of the samples, with enhanced visible emissions observed as RTP temperature increased. Similar changes are observed on the intensity ratios of the D over G peaks and the visible emission around 600 nm over the near-band-edge emission. This indicates that besides zinc vacancy (VZn) and oxygen vacancy (VO), which are popularly ascribed as the origins of the visible emissions around 500 and 550 nm, carbon clusters may be a possible origin of the visible emission around 600 nm. Finally, carbon clusters formed in the grain boundary are also supposed to at least partly be responsible for the type transition caused by RTP. [ABSTRACT FROM AUTHOR]

Study design:A case report of spinal arteriovenous malformation presented as chest pain in a child.Objectives:To illustrate the atypical clinical presentation as right chest pain in a child with spinal cord arteriovenous malformation.Setting:Chang Gung Memorial Hospital and Chang Gung University, Taiwan.Case report:An 8-year-old boy was diagnosed with spinal cord arteriovenous malformation after paraplegia. However, early diagnosis was delayed for the atypical initial clinical presentation as chest pain. After surgery and rehabilitation for 6 months, the patient could walk without assistance.Conclusions:Correct diagnosis of spinal cord arteriovenous malformations is sometimes difficult in children with atypical presentations. Early diagnosis relies on detailed examination and high index of suspicion.Spinal Cord (2008) 46, 456–458; doi:10.1038/sj.sc.3102133; published online 23 October 2007 [ABSTRACT FROM AUTHOR]