Germanium selenide monolayer is promising in photoelectric applications for its natural p-type semiconductor and complicated band structures. Basic experimental investigations of few-to-monolayer germanium selenide are still absent; major scientific challenge is to develop of techniques for controllably thinned monolayers. In this study laser thinned monolayer germanium selenide on SiO 2 /Si substrates is demonstrated. A broad photoluminescence spectrum with eight continues peaks is observed from visible to infrared wavebands centered at ≈589, 655, 737, 830, 1034, 1178, 1314, and 1456 nm, respectively. First-principle calculations based on density functional theory illuminate the band structures of few-to-monolayer germanium selenide. Photoluminescence investigation combined with first-principle calculations indicates that the indirect to direct bandgap transition happens at few layers of N = 3. Current-voltage and photoresponse characteristics of monolayer based devices show 3.3 times the photosensitivity and much faster falling edges compared with those of the pristine nanosheet based devices. The present results provide useful insight into deep understanding of thickness dependent performances of germanium selenide monocrystalline.

Wireless soft-bodied robots at the millimeter scale allow traversing very confined unstructured terrains with minimal invasion and safely interacting with the surrounding environment. However, existing untethered soft millirobots still lack the ability of climbing, reversible controlled surface adhesion, and long-term retention on unstructured three-dimensional (3D) surfaces, limiting their use in biomedical and environmental applications. Here, we report a fundamental peeling-and-loading mechanism to allow untethered soft-bodied robots to climb 3D surfaces by using both the soft-body deformation and whole-body motion of the robot under external magnetic fields. This generic mechanism is implemented with different adhesive robot footpad designs, allowing vertical and inverted surface climbing on diverse 3D surfaces with complex geometries and different surface properties. With the unique robot footpad designs that integrate microstructured adhesives and tough bioadhesives, the soft climbing robot could achieve controllable adhesion and friction to climb 3D soft and wet surfaces including porcine tissues, which paves the way for future environmental inspection and minimally invasive medicine applications.

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This paper aims at realizing an automatic parking method through a bird's eye view vision system. With this method, vehicles can make robust and real-time detection and recognition of parking spaces. During parking process, the omnidirectional information of the environment can be obtained by using four on-board fisheye cameras around the vehicle, which are the main part of the bird's eye view vision system. In order to achieve this purpose, a polynomial fisheye distortion model is firstly used for camera calibration. An image mosaicking method based on the Levenberg-Marquardt algorithm is used to combine four individual images from fisheye cameras into one omnidirectional bird's eye view image. Secondly, features of the parking spaces are extracted with a Radon transform based method. Finally, double circular trajectory planning and a preview control strategy are utilized to realize autonomous parking. Through experimental analysis, we can see that the proposed method can get effective and robust real-time results in both parking space recognition and automatic parking.

A murine homologue of the epithelial membrane protein 2 (EMP2) gene was identified in a search for genes associated with B-cell lymphoma tumorigenicity by using suppression subtractive hybridization. Expression of EMP2 messenger RNA in primary mouse tissues was limited to certain epithelial cell types and the peritoneal lymphoid compartment. EMP2 was expressed in the poorly tumorigenic DAC B-lymphoma cell line but was significantly down-regulated in a subline selected for in vivo tumor formation in Balb/c mice. Recombinant restoration of EMP2 expression in the subline suppressed its tumorigenicity, suggesting that loss of EMP2 was a causal factor in the malignant phenotype. Recombinant overexpression of EMP2 was studied in B lymphoma and NIH3T3 cells. EMP2 in both cell types induced cell death on serum deprivation. EMP2-induced cell death correlated with the expression level of EMP2 protein and was prevented by caspase inhibitors Z-VAD and Z-DEVD. These findings for the first time describe an apoptotic effect of a GAS3 family gene in lymphocytes. They also suggest that EMP2 may influence B-lymphoma tumorigenicity through a functional tumor suppressor phenotype. ( IntroductionB-cell lymphoma is among the more common classes of human malignancies, with the number of cases doubling over the past 20 years. Lymphomas are generally multifocal at the time of diagnosis and progress over time to more aggressive phenotypes, including invasion of extranodal sites and resistance to therapy. 1 A number of molecular targets have been identified in natural B-cell lymphomagenesis (eg, c-myc, bcl-2, bcl-6) with important roles in the molecular pathophysiology of corresponding classes of lymphomas (Burkitt, follicular, and diffuse large cell lymphomas, respectively). 2,3 However, in vivo and in vitro experimentation has shown that activation of these genes individually is insufficient for a malignant phenotype. Relatively few collaborating genes have been identified for the progression to malignancy, notably those involving checkpoint control and genomic stability. [4][5][6][7] The malignant phenotype involves the roles of several biologic traits in addition to growth control. 8 For example, in tumors arising in breast and prostate, invasion and metastasis are associated with altered expression of molecules affecting tumor-stromal and -endothelial interactions: matrix proteinases and proteinase inhibitors, and the integrin receptors. 9,10 In B-cell lymphomagenesis, there is also evidence for host-tumor interactions involving immune function either directly or through its action against lymphomagenic microbial infection. 11 To characterize host-tumor interaction in B-cell lymphomagenesis, our laboratory previously established a murine model system. 12-14 The DAC cell line was generated from the spontaneous in vitro outgrowth of splenic lymphocytes. Thus, DAC cells were not selected for in vivo growth and generally failed to form tumors in syngeneic immunocompetent mice. From the exceptional DAC tumors that did occur, malignant v...