3,044 research outputs found
Quantum dense coding scheme via cavity decay
We investigate a secure scheme for implementing quantum dense coding via
cavity decay and liner optics devices. Our scheme combines two distinct
advantages: atomic qubit sevres as stationary bit and photonic qubit as flying
bit, thus it is suitable for long distant quantum communication.Comment: 5 pages, 2 figure. A revised version, accept for publication in
Journal of Modern Optc
Mathematical Treatment of Phase Transformation and Analytical Calculation Method of Restraint Stress-Strain(Welding Mechanics, Strength & Design)
Scheme for sharing classical information via tripartite entangled states
We investigate schemes for quantum secret sharing and quantum dense coding
via tripartite entangled states. We present a scheme for sharing classical
information via entanglement swapping using two tripartite entangled GHZ
states. In order to throw light upon the security affairs of the quantum dense
coding protocol, we also suggest a secure quantum dense coding scheme via W
state in analogy with the theory of sharing information among involved users.Comment: 4 pages, no figure. A complete rewrritten vession, accepted for
publication in Chinese Physic
Wind Tunnel Tests on Aerodynamic Characteristics of Ice-Coated 4-Bundled Conductors
Wind tunnel tests were carried out to obtain the static aerodynamic characteristics of crescent iced 4-bundled conductors with different ice thicknesses, initial ice accretion angles, bundle spaces, and wind attack angles. The test models were made of the actual conductors and have a real rough surface. Test results show that the influence of wake interference on the drag coefficients of leeward subconductors is obvious. The interference angle range is larger than 20° and the drag coefficient curves of leeward subconductors have a sudden decrease phenomenon at some certain wind attack angles. The absolute value of the lift and moment coefficient increases with the increase of the ice thickness. In addition, the galloping of the iced subconductor may occur at the angle of wind attack near ±20° and the wake increases the moment coefficient. The variation of initial ice accretion angle has a significant influence on the aerodynamic coefficients. The aerodynamic coefficient curves exhibit a “moving” phenomenon at different initial ice accretion angles. The bundle spaces have a great influence on the moment coefficient of leeward thin ice-coated conductors. With the increase of ice thickness, the bundle spaces generally have little influence on the aerodynamic coefficients
Combined anterior and posterior surgery for treatment of cervical fracture-dislocation in patients with ankylosing spondylitis
ObjectiveTo discuss the pathological characteristics of cervical spinal fracture complicating ankylosing spondylitis (AS) and the effect of combined anterior and posterior operation.MethodsEighteen AS patients with traumatic cervical fracture-dislocation were treated operatively from January 2000 to January 2006. The symptom duration of AS was 14.5 years on average. Three cases had undergone osteotomy in lumbar spine. There were 4 cases of Grade A, 3 cases of Grade B, 9 cases of Grade C and 2 cases of Grade D according to Frankel's score. There were 15 cases of Grade III dislocation and 3 cases of Grade II. All patients underwent surgical procedures by combined anterior and posterior approach.ResultsThere were 4 anterior-posterior procedures, 8 anterior-posterior-anterior procedures and 6 posterior-anterior procedures. Seven patients had one stage operation and 11 cases underwent two stage surgeries. There was certain extent of neurological improvement in 14 incomplete paraplegic patients, but no improvement in 4 complete paraplegic patients. The follow-up period was 21.2 months on average and the time for bone fusion was 3.6 months. There were 4 complications during operation and a long-term complication in follow-up.ConclusionsThe study suggests that anterior combined with posterior approach makes the spine stable and relieves the pressure immediately. It is a reasonable surgical strategy for treatment of cervical spinal fracture-dislocation with AS
Current Advances in Mass Spectrometry Imaging for Insect Physiology and Metabolism
Research regarding the distribution of metabolites is a vital aspect of insect molecular biology. However, current approaches (e.g., liquid chromatography-mass spectrometry or immunofluorescence) have cons like requirement of massive tissues, low efficiency, and complicated operating processes. As an emerging technology, mass spectrometry imaging (MSI) can visualize the spatiotemporal distribution of molecules in biological samples without labeling. In this chapter, we retrospect the major types of in situ measurement by MSI, and the application of MSI for investigating insect endogenous and exogenous metabolites and monitoring the dynamic changes of metabolites involved with the interactions between insects and plants. Future studies that combine MSI with other genetic tools can facilitate to better explore the underlying mechanisms concerning insect physiology and metabolism
Meta-analysis of quantitative diffusion-weighted MR imaging in the differential diagnosis of breast lesions
BACKGROUND: To determine, in a meta-analysis, the diagnostic performance of quantitative diffusion-weighted (DW) MR imaging in patients with breast lesions. METHODS: English and Chinese studies published prior to June 2009 to assess the diagnostic performance of quantitative DWI in patients with breast lesions were reviewed and summarized with reference to the inclusion and exclusion criteria. Methodological quality was assessed by using the quality assessment of diagnostic studies (QUADAS) instrument. Publication bias analysis was performed by using Comprehensive Meta-analysis version 2. Meta-Disc version 1.4 was used to describe primary results and explore homogeneity by Chi-square test and inconsistency index; to explore threshold effect by receiver operator characteristic (ROC) space and Spearman correlation coefficient; and to pool weighted sensitivity and specificity by fixed or random effect model. A summary ROC (sROC) curve was constructed to calculate the area under the curve (AUC). RESULTS: Of 65 eligible studies, 13 with 615 malignant and 349 benign lesions were included in the original meta-analysis, among which heterogeneity arising from factors other than threshold effect and publication bias was explored. Methodological quality was moderate. The pooled weighted sensitivity and specificity with corresponding 95% confidence interval (CI) in one homogenous subgroup of studies using maximum b = 1000 s/mm(2 )were 0.84 (0.80, 0.87) and 0.84 (0.79, 0.88) respectively. AUC of sROC was 0.9085. Sensitivity analysis demonstrated that the pooled estimates were stable and reliable. CONCLUSIONS: Quantitative DWI has a higher specificity to differentiate between benign and malignant breast lesions compared to that of contrast-enhanced MRI. However, large scale randomized control trials (RCTs) are necessary to assess its clinical value because of disunified diffusion gradient factor b and diagnosis threshold
NADPH Oxidase 1 and Its Derived Reactive Oxygen Species Mediated Tissue Injury and Repair
Reactive oxygen species are mostly viewed to cause oxidative damage to various cells and induce organ dysfunction after ischemia-reperfusion injury. However, they are also considered as crucial molecules for cellular signal transduction in biology. NADPH oxidase, whose only function is reactive oxygen species production, has been extensively investigated in many cell types especially phagocytes. The deficiency of NADPH oxidase extends the process of inflammation and delays tissue repair, which causes chronic granulomatous disease in patients. NADPH oxidase 1, one member of the NADPH oxidase family, is not only constitutively expressed in a variety of tissues, but also induced to increase expression in both mRNA and protein levels under many circumstances. NADPH oxidase 1 and its derived reactive oxygen species are suggested to be able to regulate inflammation reaction, cell proliferation and migration, and extracellular matrix synthesis, which contribute to the processes of tissue injury and repair
Magnetic resonance imaging and mammographic appearance of dermatofibrosarcoma protuberans in a male breast: a case report and literature review
<p>Abstract</p> <p>Introduction</p> <p>Dermatofibrosarcoma protuberans is a rare low-grade soft tissue neoplasm with trunk and extremities being the most common sites of involvement. We report a rare case of male breast with dermatofibrosarcoma protuberans and its imaging features. To our knowledge the imaging appearance of dermatofibrosarcoma protuberans of the breast has never been reported in the literature.</p> <p>Case presentation</p> <p>We report the imaging appearance of dermatofibrosarcoma protuberans on the breast of a 41-year-old Chinese man who initially presented with a palpable lump. A mammogram showed two lesions, one with well circumscribed and the other with an ill defined border, in his right breast. Conventional magnetic resonance imaging was performed and showed the well defined larger lesion with mild central hypointensity while the smaller lesion had an irregular border. Both lesions were well characterized on the fat-suppressed sequences.</p> <p>Conclusions</p> <p>Dermatofibrosarcoma protuberans is a rare soft tissue sarcoma and its occurrence on the breast is even rarer. Mammography and magnetic resonance imaging can help in characterizing the lesion and localizing the lesion for further diagnostic evaluation and surgical planning.</p
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