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Background Spatial positioning is the key function of a surgical navigation robot system, and accuracy is the most important performance index of such a system. Methods The kinematic parameters of a six degrees of freedom (DOF) robot arm were used to form the transformation from intraoperative fluoroscopy images to a robot's coordinate system without C-arm calibration and to solve the redundant DOF problem. The influences of three typical error sources and their combination on the final navigation error were investigated through Monte Carlo simulation. Results The navigation error of the proposed method is less than 0.6 mm, and the feasibility was verified through cadaver experiments. Error analysis suggests that the robot kinematic error has a linear relationship with final navigation error, while the image error and gauge error have nonlinear influences. Conclusions This kinematic parameters based method can provide accurate and convenient navigation for orthopedic surgeries. The result of error analysis will help error design and assignment for surgical robots.

We report the colloidal synthesis of monodisperse nanocrystals (NCs) of InSb, which is an important member of III-V semiconductor family. Colloidal InSb NC quantum dots showed well-resolved excitonic transitions in the near-infrared spectral range, with the optical band gaps tunable from ∼1.03 eV (1200 nm) to ∼0.71 eV (1750 nm) corresponding to 3.3 and 6.5 nm InSb NCs, respectively. We observed size-tunable band edge photoluminescence that could be significantly enhanced by growing InSb/CdSe or InSb/CdS core-shell nanostructures. Films of InSb NCs capped with S(2-) ions showed ambipolar charge transport.

Image guided navigation systems (IGNS) have been implemented successfully in orthopaedic trauma surgery procedures because of their ability to help surgeons position and orient hand-held drills at optimal entry points. However, current IGNS cannot prevent drilling tools or instruments from slipping or deviating from the planned trajectory during the drilling process. A method is therefore needed to overcome such problems.A novel passive/active hybrid robot (the HybriDot) for positioning and supporting surgical tools and instruments while drilling and/or cutting in orthopaedic trauma surgery is presented in this paper. This new robot, consisting of a circular prismatic joint and five passive/active back-drivable joints, is designed to fulfill clinical needs. In this paper, a system configuration and three operational modes are introduced and analyzed. Workspace and layout in the operating theatre (OT) are also analyzed in order to validate the structure design. Finally, experiments to evaluate the feasibility of the robot system are described.Analysis, simulation, and experimental results show that the novel structure of the robot can provide an appropriate workspace without risk of collision within OT environments during operation. The back-drivable joint mechanism can provide surgeons with more safety and flexibility in operational modes. The mean square value of the positional accuracy of this robot is 0.811 mm, with a standard deviation (SD) of 0.361 mm; the orientation is accurate to within 2.186º, with a SD of 0.932º. Trials on actual patients undergoing surgery for distal locking of intramedullary nails were successfully conducted in one pass using the robot.This robot has the advantages of having an appropriate workspace, being well designed for human-robot cooperation, and having high accuracy, sufficient rigidity, and easy deployability within the OT for use in common orthopaedic trauma surgery tasks such as screw fixation and drilling assistance.

All-inorganic colloidal nanocrystals were synthesized by replacing organic capping ligands on chemically synthesized nanocrystals with metal-free inorganic ions such as S(2-), HS(-), Se(2-), HSe(-), Te(2-), HTe(-), TeS(3)(2-), OH(-) and NH(2)(-). These simple ligands adhered to the NC surface and provided colloidal stability in polar solvents. The versatility of such ligand exchange has been demonstrated for various semiconductor and metal nanocrystals of different size and shape. We showed that the key aspects of Pearson's hard and soft acids and bases (HSAB) principle, originally developed for metal coordination compounds, can be applied to the bonding of molecular species to the nanocrystal surface. The use of small inorganic ligands instead of traditional ligands with long hydrocarbon tails facilitated the charge transport between individual nanocrystals and opened up interesting opportunities for device integration of colloidal nanostructures.

The mitochondrial transcription factor A (TFAM) is required for mitochondrial DNA (mtDNA) replication and transcription. Disruption of TFAM results in heart failure and premature aging in mice. But very little is known about the role of TFAM in cancer development. Here, we report the identification of frequent frameshift mutations in the coding mononucleotide repeat of TFAM in sporadic colorectal cancer (CRC) cell lines and in primary tumors with microsatellite instability (MSI), but not in microsatellite stable (MSS) CRC cell lines and tumors. The presence of the TFAM truncating mutation, in CRC cells with MSI, reduced the TFAM protein level in vivo and in vitro and correlated with mtDNA depletion. Furthermore, forced overexpression of wild-type TFAM in RKO cells carrying a TFAM truncating mutation suppressed cell proliferation and inhibited RKO cell-induced xenograft tumor growth. Moreover, these cells showed more susceptibility to cisplatin-induced apoptosis due to an increase of cytochrome b (Cyt b) expression and its release from mitochondria. An interaction assay between TFAM and the heavy-strand promoter (HSP) of mitochondria revealed that mutant TFAM exhibited reduced binding to HSP, leading to reduction in Cyt b transcription. Collectively, these data provide evidence that a high incidence of TFAM truncating mutations leads to mitochondrial copy number reduction and mitochondrial instability, distinguishing most CRC with MSI from MSS CRC. These mutations may play an important role in tumorigenesis and cisplatin-induced apoptotic resistance of most microsatellite-unstable CRCs. Cancer Res; 71(8); 2978–87. ©2011 AACR.

This work describes a novel methodology for unequivocal identification of chemical constituents in Zhimu-Baihe herb-pair (ZMBHHP). Compounds were removed from ZMBHHP by ultrasonic extraction with 70% ethanol, and then analyzed by fast high-performance liquid chromatography (HPLC) coupled with time-of-flight mass spectrometry (TOFMS). The accurate-mass capability of the TOF analyzer allowed reliable confirmation of the identity of the detected compounds, normally with mass errors below 3 ppm in routine analysis. This mass accuracy was sufficient to verify the elemental compositions of the chemical constituents in ZMBHHP. With dynamic adjustment of fragmentor voltage in TOFMS, an efficient ion transmission was achieved to obtain the best sensitivity and abundant fragmentation. By accurate mass measurements for each molecular ion and subsequent fragment ions, a reliable identification and differentiation of 24 saponins, 3 xanthones, 1 anthraquinone and 2 alkaloids was described here, including four groups of isomers. It is concluded that this fast and sensitive HPLC/ESI-TOFMS technique is powerful in qualitative analysis of complex herbal medicines in terms of sensitivity, selectivity, resolving power, time savings and lower solvent consumption. Furthermore, the data gathered in this study may be helpful for understanding the synergistic nature of this herb pair in traditional Chinese medicine (TCM) and further pharmacokinetic studies of ZMBHHP. Copyright © 2010 John Wiley & Sons, Ltd.

Network detection in large distributed systems is a challenging task which requires accurate detect whether there exist fault. Exist works in active probing mainly use entropy-criterion; however, in practical, there exists several quality functions in network. In this paper, we present an approach, which can perform well under multi quality function conditions. We simulate our algorithm and other algorithm for network detection, the result shows that our algorithm will cost a Our algorithm guarantees solutions greatly improve the performance of detection set, at only a slightly higher cost.

NMI (network management interfaces) are important part of network management system. The conformance testing of NMI is an important mean to ensure interconnection, inter-working, interoperability among management systems. In order to complete complex function or service test for NMI, a series of test cases must be organized together with logical relationship to compose test transaction. Using test transaction to execute test automatically can improve test efficiency and reduce test cost. Currently, test transaction is described by script format and can not support visual edit. This paper presents a Graphical Presentation Format to describe test transaction so that test transaction is easily edited and showed flexibility.

Entry position of the graft is very important in anterior cruciate ligament (ACL) reconstruction. However the determination of entry position is very difficult to the surgeon. In this paper, a navigation and evaluation system assisted by the 6-DOFS robot is implemented for the simulation evaluation and planning insertion points based on quadrant method for the femur and Staublis method for the tibia on the lateral X-ray image of knee joint. Meanwhile, the implementation of the key technologies such as image correction, image registration, C-arm calibration, video tracking, bone surface reconstruction, image fusion, 6-DOFS robot, and virtual simulation are introduced. Finally, Experiments about the tunnel planning method and real time tracking of surgical apparatus are implemented on 8 bone of plastic models (Sawbone, Swiss) and 10 bones of the goat. In the experiment, the tibia rotates around the femur under the surgeon's implementation to evaluate the planning result with the virtual simulation and evaluation module. The positioning error is 1.59mm from analysis on 30 space targets. The virtual reconstruction ACL is satisfied with two important criteria of the best isometry and collision detection between graft and intercondylar surface of femur. The results are well accepted in operations. In order to satisfying with the request of exact operation in ACL reconstruction, we have developed 6-DOFS passive robot to assist the surgeons entry positioning and drilling of implant tunnels, implementing exact operation in knee joint.

The development process of joint kinematics and kinetics is expatiated from the aspects of technology and method. Firstly, the classical mechanics-based methods are introduced. Secondly, the computer assisted methods are analyzed from the technical aspects of video tracking, fluoroscopy and MR imaging separately. Then the assistance of robotic technique in this field is discussed. Finally the potential trend in the joint kinematics and kinetics is concluded.

Five compounds were isolated from the roots of Patrinia scabra Bunge separated and purified on sillica gel column chromatography. Their structures were elucidated on the physico-chemical properties and spectral data as lariciresinol(I), syringaresinol(II), scopoletin(III), quercetin(IV), ferulaic acid(V). All compounds were obtained from P. scabra for the first time. In vitro biological test of these compounds showed that syringaresinol was able to stimulate T and B lymphocyte proliferation.

The synthesis, characterization and catalytic capability of the NiW-nano-hydroxyapatite (NiW-nHA) composite were investigated in this paper. The NiW-nHA catalyst was prepared by a co-precipitation method. Then Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDX) were used to analyze this material. In addition, the catalytic capacity of the NiW-nHA composite was also examined by FT-IR and gas chromatography (GC). The results of FT-IR analysis indicated that Ni, W and nHA combined closely. TEM observation revealed that this catalyst was needle shaped and the crystal retained a nanometer size. XRD data also suggested that a new phase of CaWO(4) appeared and the lattice parameters of nHA changed in this system. nHA was the carrier of metals. The rates of Ni/W-loading were 73.24% and 65.99% according to the EDX data, respectively. Furthermore, the conversion of 91.88% Jatropha oil was achieved at 360 °C and 3 MPa h(-1) over NiW-nHA catalyst. The straight chain alkanes ranging from C(15) to C(18) were the main components in the production. The yield of C(15)-C(18) alkanes was up to 83.56 wt%. The reaction pathway involved hydrocracking of the C═C bonds of these triglycerides from Jatropha oil. This paper developed a novel non-sulfided catalyst to obtain a "green biofuel" from vegetable oil.