3,579 research outputs found
Posterior-only spinal fusion without rib head resection for treating type I neurofibromatosis with intra-canal rib head dislocation
OBJECTIVES: Patients with Type I neurofibromatosis scoliosis with intra-canal rib head protrusion are extremely rare. Current knowledge regarding the diagnosis and treatment for this situation are insufficient. The purpose of this study is to share our experience in the diagnosis and surgical treatments for such unique deformities. METHODS: Six patients with Type I neurofibromatosis scoliosis with rib head dislocation into the spinal canal were diagnosed at our institution. Posterior instrumentation and spinal fusion without intra-canal rib head resection via a posterior-only approach was performed for deformity correction and rib head extraction. The efficacy and outcomes of the surgery were evaluated by measurements before, immediately and 24 months after the surgery using the following parameters: coronal spinal Cobb angle, apex rotation and kyphosis of the spine and the intra-canal rib head position. Post-operative complications, surgery time and blood loss were also evaluated. RESULTS: Patients were followed up for at least 24 months post-operatively. The three dimensional spinal deformity was significantly improved and the intra-canal rib head was significantly extracted from the canal immediately after the surgery. At follow-up 24 months after surgery, solid fusions were achieved along the fusion segments, and the deformity corrections and rib head positions were well maintained. There were no surgery-related complications any time after the surgery. CONCLUSIONS: Systematic examinations are needed to identify patients with Type I neurofibromatosis scoliosis with rib head dislocation into the canal who can be treated by posterior-only spinal fusion without rib head resection
Efficacy of sorafenib on metastatic renal cell carcinoma in Asian patients: Results from a multicenter study
<p>Abstract</p> <p>Background</p> <p>The effects of sorafenib in the treatment of advanced renal cell carcinoma (RCC) have been confirmed in an international collaborative phase III trial. This study aims to confirm similar efficacy and treatment-induced toxicities of sorafenib in the treatment of metastatic RCC in ethnic Chinese patients.</p> <p>Methods</p> <p>Ninety-eight consecutive and non-selected patients with pathologically confirmed metastatic RCC were treated according to an institutional treatment protocol. All patients were treated with 400 mg of sorafenib orally twice daily on a continuous basis until disease progression or intolerance to treatment occurred. Dose reduction to 400 mg once daily was required if grade 3 or 4 toxicities occurred. All patients except for 7 received nephrectomy in the course of their disease. All patients were assessed for tumor response, progression-free survival (PFS), overall survival (OS), and treatment-induced toxicities.</p> <p>Results</p> <p>The median follow-up time was 76 weeks (range 2–296 weeks) for the entire group of patients. Radiologically confirmed complete response (CR), partial response (PR), stable disease (SD) of more than 4 months, and disease progression as best objective responses were observed in 1 (1%), 23 (23.5%), 62 (63.3%), and 12 (12.2%) patients, respectively. The tumor control rate (CR+PR+SD of >4 months) was 87.8%. The 1-year estimated PFS and OS were 58.4% and 64.6%, respectively. The median progression-free survival (PFS) time was 60 weeks (95% CI 41–79); and the median overall survival (OS) time was not reached with a follow-up of 76 weeks. Reduction of sorafenib dose was required in 26 patients who developed grade 3 or 4 treatment-cause adverse-effects. An additional 9 patients discontinued sorafenib treatment due to severe adverse-effects. No grade 5 toxicity occurred.</p> <p>Multivariate analysis revealed that independent predictive factors for tumor response to sorafenib treatment included ECOG status, presence of lymph node metastasis, and nephrectomy prior to the development of metastasis.</p> <p>Conclusion</p> <p>Sorafenib produced an 87.8% disease control rate for metastatic renal cell carcinoma in Chinese patients, with acceptable rates of toxicity. The medication dosed at 400 mg twice daily is both efficacious and safe in the treatment of metastatic renal cell carcinoma in Chinese patients.</p
Jahn-Teller distortion induced charge-ordering in CE phase of manganites
The charge order of CE phase in half-doped manganites is studied, based on an
argument that the charge-ordering is caused by the Jahn-Teller distortions of
MnO6 octahedra rather than Coulomb repulsion between electrons. The uantitative
calculation on the ferromagnetic zigzag chain as the basic structure unit of CE
phase within the framework of two-orbital double exchange model including
Jahn-Teller effect is performed, and it is shown that the
charge-disproportionation of Mn cations in the charge-ordered CE phase is less
than 13%. In addition, we predict the negative charge-disproportionation once
the Jahn-Teller effect is weak enough.Comment: 12 pages, 4 figures(contained in the pdf file). submitted to Physical
Review
Electronic and Transport Properties of Radially Deformed Double-walled Carbon Nanotube Intramolecular Junction
The electronic and transport property of a radially deformed double-walled
carbon nanotube (DWNT) intramolecular junction (IMJ) has been studied by the
tight-binding (TB) model combined with the first-principle calculations. The
geometrical structures of the DWNT IMJ have been first optimized in energy by
the universal force field (UFF) method. It is found that when heavily squashed,
the DWNT will become an insulator-coated metallic wire, and the conductance
near the Fermi level has been significantly changed by the radial squash.
Specially, several resonance conductance peaks appear at some energies in the
conduction band of the squashed DWNT IMJ. Finally, we have also investigated
the conductance variation due to change of the length of the central
semiconductor in the squashed DWNT IMJ. Furthermore, a promising pure carbon
nanoscale electronic device is proposed based on the DWNT IMJ.Comment: 11 pages, 4 figure
Robust normalization and guaranteed cost control for a class of uncertain singular Markovian jump systems via hybrid impulsive control
This paper investigates the problem of robust normalization and guaranteed cost control for a class of uncertain singular Markovian jump systems. The uncertainties exhibit in both system matrices and transition rate matrix of the Markovian chain. A new impulsive and proportional-derivative control strategy is presented, where the derivative gain is to make the closed-loop system of the singular plant to be a normal one, and the impulsive control part is to make the value of the Lyapunov function does not increase at each time instant of the Markovian switching. A linearization approach via congruence transformations is proposed to solve the controller design problem. The cost function is minimized via solving an optimization problem under the designed control scheme. Finally, three examples (two numerical examples and an RC pulse divider circuit example) are provided to illustrate the effectiveness and applicability of the proposed methods
Mapping forests in monsoon Asia with ALOS PALSAR 50-m mosaic images and MODIS imagery in 2010.
Extensive forest changes have occurred in monsoon Asia, substantially affecting climate, carbon cycle and biodiversity. Accurate forest cover maps at fine spatial resolutions are required to qualify and quantify these effects. In this study, an algorithm was developed to map forests in 2010, with the use of structure and biomass information from the Advanced Land Observation System (ALOS) Phased Array L-band Synthetic Aperture Radar (PALSAR) mosaic dataset and the phenological information from MODerate Resolution Imaging Spectroradiometer (MOD13Q1 and MOD09A1) products. Our forest map (PALSARMOD50 m F/NF) was assessed through randomly selected ground truth samples from high spatial resolution images and had an overall accuracy of 95%. Total area of forests in monsoon Asia in 2010 was estimated to be ~6.3 × 10(6 )km(2). The distribution of evergreen and deciduous forests agreed reasonably well with the median Normalized Difference Vegetation Index (NDVI) in winter. PALSARMOD50 m F/NF map showed good spatial and areal agreements with selected forest maps generated by the Japan Aerospace Exploration Agency (JAXA F/NF), European Space Agency (ESA F/NF), Boston University (MCD12Q1 F/NF), Food and Agricultural Organization (FAO FRA), and University of Maryland (Landsat forests), but relatively large differences and uncertainties in tropical forests and evergreen and deciduous forests
Doping-dependent Phase Diagram of LaO{\it M}As ({\it M}=V--Cu) and Electron-type Superconductivity near Ferromagnetic Instability
By first-principles calculations, we present a doping-dependent phase diagram
of LaO{\it M}As ({\it M}=V--Cu) family. It is characterized as
antiferromagnetic semiconductor around LaOMnAs side and ferromagnetic metal
around LaOCoAs. Both LaOFeAs and LaONiAs, where superconductivity were
discovered, are located at the borderline of magnetic phases. Extensive Fermi
surface analysis suggests that the observed superconductivity is of
electron-type in its origin. We discuss possible pairing mechanisms in the
context of competing ferromagnetic phases found in this work and the
ferromagnetic spin fluctuations.Comment: 4 pages, 1 table, 3 figure
Global analysis of the rat and human platelet proteome - the molecular blueprint for illustrating multi-functional platelets and cross-species function evolution
Emerging evidences indicate that blood platelets function in multiple biological processes including immune response, bone metastasis and liver regeneration in addition to their known roles in hemostasis and thrombosis. Global elucidation of platelet proteome will provide the molecular base of these platelet functions. Here, we set up a high throughput platform for maximum exploration of the rat/human platelet proteome using integrated proteomics technologies, and then applied to identify the largest number of the proteins expressed in both rat and human platelets. After stringent statistical filtration, a total of 837 unique proteins matched with at least two unique peptides were precisely identified, making it the first comprehensive protein database so far for rat platelets. Meanwhile, quantitative analyses of the thrombin-stimulated platelets offered great insights into the biological functions of platelet proteins and therefore confirmed our global profiling data. A comparative proteomic analysis between rat and human platelets was also conducted, which revealed not only a significant similarity, but also an across-species evolutionary link that the orthologous proteins representing ‘core proteome’, and the ‘evolutionary proteome’ is actually a relatively static proteome
Electronic structure of optimally doped pnictide BaKFeAs: a comprehensive ARPES investigation
We have conducted a comprehensive angle-resolved photoemission study on the
normal state electronic structure of the Fe-based superconductor
BaKFeAs. We have identified four dispersive bands which
cross the Fermi level and form two hole-like Fermi surfaces around and
two electron-like Fermi surfaces around M. There are two nearly nested Fermi
surface pockets connected by an antiferromagnetic (, ) wavevector.
The observed Fermi surfaces show small dispersion and a total volume
consistent with Luttinger theorem. Compared to band structure calculations, the
overall bandwidth is reduced by a factor of 2. However, many low energy
dispersions display stronger mass renormalization by a factor of 4,
indicating possible orbital (energy) dependent correlation effects. Using an
effective tight banding model, we fitted the band structure and the Fermi
surfaces to obtain band parameters reliable for theoretical modeling and
calculations of the important physical quantities, such as the specific heat
coefficient.Comment: 13 pages, 4 figure
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