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A novel ultra-long-distance (up to 76 km) fibre Bragg grating (FBG) sensor system based on a spectrum-limited Fourier domain modelocking fibre laser is proposed. Raman pumps are employed to form a Raman amplifier to compensate the transmission loss of the long fibre and ensure ultra-long-distance sensing. Strain sensing based on such an ultra-long-distance FBG sensor system is demonstrated with a signal-to-noise ratio over 22 dB and a sensitivity of 1.03 pm/µℇ in the wavelength domain or 18.3 ns/µℇ in the time domain. [ABSTRACT FROM AUTHOR]

A simple dual-wavelength single-longitudinal-mode erbium-doped fibre laser is proposed by incorporating a fibre Bragg grating pair, which is used as a Fabry-Perot filter with two ultra-narrow (∼0.12 pm) transmission bands. Stable dual-wavelength single-longitudinal-mode lasing with a wavelength spacing of ∼0.08 nm is achieved at room temperature. By beating the dual-wavelengths at a photodetector, a microwave signal at 9.616 GHz is demonstrated with a frequency stability better than 1 MHz and a spectral width less that 10 kHz. [ABSTRACT FROM AUTHOR]

A frequency doubling approach for optical generation of tunable microwave and millimetre-wave signals is proposed and verified experimentally. The experimental setup is based on an optical phase modulator and a simple uniform fibre Bragg grating. The generated signal is of high quality and can be tuned. [ABSTRACT FROM AUTHOR]

A novel layout for an ultra-compact arrayed-waveguide grating (AWG) demultiplexer is presented. The present layout has two overlapped free propagation regions, and is more compact than a conventional layout. Using αSi-on-SiO2 nanowire waveguides, an ultra-small 4×4 AWG (about 40×50 µm2) with channel spacing of 11 nm is fabricated and characterised. [ABSTRACT FROM AUTHOR]

A novel notch filter based on a composite right/left-handed (CRLH) transmission line is proposed. The proposed CRLH transmission line is different from a conventional CRLH transmission line. The novel notch filter has a large notch depth, very small loss in the passband, and very sharp transitions at the two edges of the stop-band. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 626–628 2006; Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.21427 [ABSTRACT FROM AUTHOR]

A fibre Bragg grating feedback fibre laser with both Raman and erbium-doped fibre pumps is proposed. Dual-wavelength switching is achieved by controlling the power of the Raman pump. The characteristics of the dual-wavelength switching are studied experimentally, and the mechanism is explained physically. [ABSTRACT FROM AUTHOR]

B Background: b To compare recurrence and survival outcomes of concurrent hepatectomy with extrahepatic bile duct resection(H+BDR) and hepatectomy with only removal of bile duct tumor thrombi(H+T) for hepatocellular carcinoma(HCC) patients with bile duct tumor thrombi(BDTT). B Conclusion: b Hepatectomy combined with BDR for the HCC patients with BDTT offers decreasing recurrence at 1-year, better survival at 1-year and 3-year but similar long-term survival and should be considered when feasible. [Extracted from the article]

Structural phase transformation from multiwalled carbon nanotubes to nanocrystalline diamond by hydrogen plasma post-treatment was carried out. Ultrahigh equivalent diamond nucleation density above 1011 nuclei/cm2 was easily obtained. The diamond formation and growth mechanism was proposed to be the consequence of the formation of sp3 bonded amorphous carbon clusters. The hydrogen chemisorption on curved graphite network and the energy deposited on the carbon nanotubes by continuous impingement of activated molecular or atomic hydrogen are responsible for the formation of amorphous carbon matrix. Diamond nucleates and grows in the way similar to that of diamond chemical vapor deposition processes on amorphous carbon films. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A genetic algorithm is applied to optimize the size and location of a sleeve, which reduces parasitic currents on the surface of the feed cable of a mobile handset antenna, so that the influence of the RF cable on the radiation pattern is minimized. The pattern is calculated by the electric-field integral equation (EFIE) method in each iteration of the genetic algorithm. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 25: 194–196, 2000 [ABSTRACT FROM AUTHOR]

With cancer stem cells (CSCs) became the research hotspot, emerging studies attempt to reveal the functions of these special subsets in tumorigenesis. Although various approaches have been used in CSCs researches, only a few could really reflect or simulate the microenvironment in vivo. At present, CSCs theories are still difficult to apply for clinical remedy because CSCs subpopulations are always hard to identify and trace. Thus an ideal approach for clinicians and researchers is urgently needed. Circulating tumor cells (CTCs), as the method of noninvasive-liquid biopsy, could be detected in the peripheral blood (PB) from many tumors and even could be treated as procurators for CSCs deeper researches from patient-derived sample. However, CTCs, as a diagnostic marker, also raise much controversy over theirs clinical value. Mechanisms causing CTCs to shed from the tumor have not been fully characterized, thus it is unclear whether CTCs represent the entire makeup of cancer cells in the tumor or only a subset. The heterogeneity of CTCs also caused different clinical outcomes. To overcome these unsolved problems, recently, CTC researches are not just depend on enumerations, whereas those CTC subsets that could expand in vitro may play a pivotal role in the metastatic cascade. Here, we retrospect the CTC developmental history and discourse upon the enrichment of viable CTCs in functional assays, probe the further avenue at the crossroad. [ABSTRACT FROM AUTHOR]

Electrons can be efficiently injected into a plasma wave by colliding two counterpropagating laser pulses in a laser wakefield acceleration. However, the generation of a high-quality electron beam with a large charge is difficult in the traditional on-axis colliding scheme due to the growth of the electron beam duration coming from the increase of the beam charge. To solve this problem, we propose an off-axis colliding scheme, in which the collision point is away from the axis of the driver pulse. We show that the electrons injected from the off-axis region are highly concentered on the tail of the bubble even for a large trapped charge, thus feeling almost the same accelerating field. As a result, quasimonoenergetic electron beams with a large charge can be produced. The validity of this scheme is confirmed by both the particle-in-cell simulations and the Hamiltonian model. Furthermore, it is shown that a Laguerre-Gauss (LG) laser can be adopted as the injection pulse to realize the off-axis colliding injection in three dimensions symmetrically, which may be useful in simplifying the technical layout of the real experiment setup. [ABSTRACT FROM AUTHOR]

Two types of waveguide power splitters based on a bending multimode waveguide are demonstrated for an unbalanced power splitting ratio. An arbitrary splitting ratio is achieved by choosing the bending radius and the length of the multimode section appropriately. Experimental results show that the fabricated devices have wide bandwidth. [ABSTRACT FROM AUTHOR]

Objective: To produce a reliable objective method of assessing the House-Brackmann (H-B) and regional grades of facial palsy with the results produced and presented in a time and manner suitable for a routine clinical setting. Study design: Analysis of video pixel data using artificial neural networks (ANNs). Setting: Tertiary-referral neuro-otologic center. Subjects: Subjects with varying degrees of unilateral facial palsy. Method: Clinicians assessed videos of subjects with varying degrees of facial palsy performing prescribed movements. The results of their overall and regional assessments were used to train ANNs. These were then tested for consistency, accuracy and ability to identify clinical changes in grading. Results: A group of subjects had their objective computer assessment repeated, and consistent H-B and regional grades were obtained. A second group had both subjective clinical and objective computer assessments performed. The program gave results that were within the expected level of agreement with the subjective clinical assessment for both H-B and regional grades. A third group had repeated clinical and computer assessments from the time of onset to recovery of facial function. The changes in the computer results both for H-B and regional grades tracked the clinical change. Conclusion: It is possible to measure consistently and objectively the H-B and regional grades of facial palsy using trained ANNs to analyse video pixel data, and this can be performed in a routine clinical environment by a technician. The results from each region of the face are presented as a facogram along with the H-B grade. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To summarize the clinical manifestations and treatment of acquired hemophilia A in a patient with lumbar disc herniation. SUMMARY OF BACKGROUND DATA: Acquired hemophilia A is a rare but potentially life-threatening hemorrhagic disorder. It is caused by the development of autoantibodies directed against coagulation factor VIII (F VIII) in adults or elderly patients, who do not have a personal or family history of bleeding episodes. The mortality is high if the diagnosis was missed or delays, especially after a surgery. METHODS: A case was investigated retrospectively and the relevant literature was reviewed. RESULTS: A 59-year-old man with a 1-year history of lower back and leg pain was admitted to the hospital. He has no family medical history of hemophilia A and the routine laboratory examination did not find abnormality on blood coagulation function. He underwent decompression by laminectomy and discectomy. Seven hours after operation, it was found that the incision was oozing profusely and hemoglobin was reduced gradually, though platelet count was within the normal range. He was diagnosed with acquired factor VIII (FVIII) deficiency based on a prolonged activated partial-thromboplastin time (61.0 seconds), reduced FVIII activity (4.2%), and FVIII inhibitor (8 BU). After treatment with hemodynamic stabilization and immunosuppression therapies (including transfusion of packed red blood cells, fresh frozen plasma, and cryoprecipitate) and administration of human antihemophilic globulin, corticosteroid, and cyclophosphamide, bleeding was stopped gradually. The clinical and biologic condition of the patient improved, though neurological deficit was left. CONCLUSION: Surgical operation may be a factor contributing to acquired hemophilia A, which, to our knowledge, has not been reported in the literature. Diagnosis of acquired hemophilia requires clinical acumen and any patient who presents with bleeding and a prolonged activated partial-thromboplastin time should be considered. Initial hemodynamic stabilization followed by treatment with immunosuppressive therapy is straightforward and highly successful. [ABSTRACT FROM AUTHOR]

We present a direct observation of a structural transition at molecular scale in an organic p-nitrobenzonitrile (PNBN) thin film using scanning tunneling microscopy (STM). STM images clearly show an ordered molecular structure of unrecorded regions in the films, while the PNBN molecular arrangements are disordered in the recorded regions. The current-voltage (I-V) measurements from the STM demonstrate a great increase of the conductance transition in the recorded regions after the voltage pulses. Those results suggest that the recording mechanism may be due to a crystalline structural transition, which is consistent with our previously proposed mechanism in another organic system for ultrahigh density data storage. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]