7,920 research outputs found
Passive Mode-Locking of Monolithic InGaAs/AlGaAs Double Quantum Well Lasers at 42GHz Repetition Rate
Pulse trains with a 42GHz repetition rate were generated by monolithic InGaAs/AlGaAs double quantum well lasers at a wavelength of 985 [angstroms]. The cavity was electrically divided into three regions, one providing gain and the other two providing saturable absorption. The optical modulation has a depth greater than 98% and full-width at half-maximum under 6ps, and bias conditions for sustained mode-locking are determined
Antibiotics to improve recovery following tonsillectomy: a systematic review.
OBJECTIVE: To determine if antibiotics improve recovery following tonsillectomy. STUDY DESIGN: DATA SOURCES: Electronic databases Medline, Embase, and Cochrane Controlled Trials Register were searched using relevant search terms. Additional trials, if any, were retrieved by searching the references from all identified trials, reviews, correspondences, editorials, and conference proceedings. No language restriction was applied. STUDY SELECTION: Systematic review of trials in which antibiotic was administered as a study medication intraoperatively and/or postoperatively, in children or adults undergoing tonsillectomy or adenotonsillectomy. Only randomized, placebo-controlled, double-blind trials attaining preset quality scores were included. Outcomes analyzed: 1) pain, need for analgesia, fever, halitosis, and return to normal diet and activities; 2) secondary hemorrhage using 2 parameters-significant hemorrhage (ie, warranting readmission, blood transfusion, or return to theatre for hemostasis) and total hemorrhage; and 3) adverse events. RESULTS: Five trials met the eligibility criteria. Antibiotics significantly reduced the number of subjects manifesting fever (relative risk [RR]: 0.62, 95% confidence interval [CI]: 0.45, 0.85) and duration of halitosis (-1.94 [-3.57, -0.30] days), and marginally reduced the time taken to resume normal activity (-0.63 [-1.12, -0.14] days), but had no significant effect in reducing pain scores (-0.01 [-0.60, 0.57]) or need for analgesia. Similarly, there was no significant difference in the time taken to resume normal diet or incidence of significant and total hemorrhage, although data was underpowered to detect differences for these outcomes. In the antibiotic group 4 patients developed an adverse reaction (3 cases of rash and 1 case of oropharyngeal candidiasis), while in the control group 1 patient had an adverse reaction (rash). The RR of antibiotic-related adverse events was 2.45 (0.45, 13.31). CONCLUSION: Antibiotics appear to be effective in reducing some, but not all, morbid outcomes following tonsillectomy, and may increase the risk of adverse events. Further trials are needed to better define the role of antibiotics in facilitating post-tonsillectomy recovery. EBM RATING: A-1a
Nonlinear Stiffness and Viscoelasticity of Inhibitor-Treated Blood Clots by Tensile Testing
Although blood clots are vital to wound healing, little is known about what factors influence clot stiffness and dynamic response. This work investigates the mechanics of inhibitor-treated clots by direct tensile testing using a custom designed system for forces below 1 N. Inhibitors that affect clot formation include blebbistatin, which affects myosin II movement on actin, and cytochalasin D, which affects actin polymerization. The hypothesis of this investigation is that blebbistatin will have a greater effect on mechanical behavior than cytochalasin D, because the inhibition of myosin II will weaken the overall clot more than actin. This hypothesis was investigated using clots that were treated with blebbistatin and cytochalasin, using untreated whole blood as a reference. Clots were tested from five different donors with at least two replicates from each donor. Each clot was subjected to an initial stretch ratio of 1.5 to measure nonlinear stiffness, followed by a series of 1 mm increments to record stress relaxation. At a stretch ratio of 1.5, blebbistatin-treated clots exhibited 4.3% lower tensile stress than cytochalasin-treated clots. The relaxation time constant for blebbistatin-treated clots was 10% faster than for cytochalasin-treated clots. This evidence supports the hypothesis about the role of myosin II in blood and introduces experimental methodology that can be extended to studies on mechanics of other soft biological tissues
An information adaptive system study report and development plan
The purpose of the information adaptive system (IAS) study was to determine how some selected Earth resource applications may be processed onboard a spacecraft and to provide a detailed preliminary IAS design for these applications. Detailed investigations of a number of applications were conducted with regard to IAS and three were selected for further analysis. Areas of future research and development include algorithmic specifications, system design specifications, and IAS recommended time lines
Submilliamp threshold InGaAs-GaAs strained layer quantum-well laser
Strained-layer InGaAs-GaAs single-quantum-well buried-heterostructure lasers were fabricated by a hybrid beam epitaxy and liquid-phase epitaxy technique. Very low threshold currents, 2.4 mA for an uncoated laser (L=425 μm) and 0.75 mA for a coated laser (R~0.9, L=198 μm), were obtained. A 3-dB modulation bandwidth of 7.6 GHz was demonstrated at low bias current (14 mA). Procedures for material preparation and device fabrication are introduced
Corporate branding and value creation for initiating and managing relationships in B2B markets
Purpose
This study aims to fill a gap in branding literature concerning the effect of corporate brand relationships on brand value through the case study method in a business-to-business (B2B) context. The objectives of this study can be framed in three questions: (1) what are the main constituents of a corporate brand; (2) how does a corporate brand generate tangible and intangible brand value for their business customers; and (3) how do tangible and intangible brand benefits influence relationship initiation and management practices of the case companies?
Design/methodology/approach
The study adopts a qualitative multiple case study design by using archival data, and both in-depth telephone and online interviews with senior representatives of the case study companies to investigate corporate branding and associated issues in a B2B context.
Findings
From a managerial perspective, this study reveals that corporate business culture, brand relationships, products, and corporate identity and personality as the main constituents of a corporate brand in a B2B context. The results show that a corporate brand can generate intangible and tangible brand value benefits for business customers. The findings also note the importance of the brand value in enhancing relationship initiation.
Originality/value
The study contributes to the branding literature by developing a conceptual model that explains the development and role of the corporate brand in a B2B context with its associated value creation and brand management outcomes. The findings advance brand management literature on business relationships, which addresses a gap in B2B contexts rather than mainly about product brand management and value creation in B2C contexts
Unconventional Hall effect in oriented CaCoO thin films
Transport properties of the good thermoelectric misfit oxide
CaCoO are examined. In-plane resistivity and Hall resistance
measurements were made on epitaxial thin films which were grown on {\it c}-cut
sapphire substrates using the pulsed laser deposition technique. Interpretation
of the in-plane transport experiments relates the substrate-induced strain in
the resulting film to single crystals under very high pressure ( 5.5 GPa)
consistent with a key role of strong electronic correlation. They are confirmed
by the measured high temperature maxima in both resistivity and Hall
resistance. While hole-like charge carriers are inferred from the Hall effect
measurements over the whole investigated temperature range, the Hall resistance
reveals a non monotonic behavior at low temperatures that could be interpreted
with an anomalous contribution. The resulting unconventional temperature
dependence of the Hall resistance seems thus to combine high temperature
strongly correlated features above 340 K and anomalous Hall effect at low
temperature, below 100 K.Comment: Submitted to Physical Review B (2005
Focal Defects in Single-Celled Tubes Mutant for Cerebral Cavernous Malformation 3, GCKIII, or NSF2
Tubes of differing cellular architecture connect into networks. In the Drosophila tracheal system, two tube types connect within single cells (terminal cells); however, the genes that mediate this interconnection are unknown. Here we characterize two genes that are essential for this process: lotus, required for maintaining a connection between the tubes, and wheezy, required to prevent local tube dilation. We find that lotus encodes N-ethylmaleimide sensitive factor 2 (NSF2), whereas wheezy encodes Germinal center kinase III (GCKIII). GCKIIIs are effectors of Cerebral cavernous malformation 3 (CCM3), a protein mutated in vascular disease. Depletion of Ccm3 by RNA interference phenocopies wheezy; thus, CCM3 and GCKIII, which prevent capillary dilation in humans, prevent tube dilation in Drosophila trachea. Ectopic junctional and apical proteins are present in wheezy terminal cells, and we show that tube dilation is suppressed by reduction of NSF2, of the apical determinant Crumbs, or of septate junction protein Varicose
A uniform proteomics MS/MS analysis platform utilizing open XML file formats
The analysis of tandem mass (MS/MS) data to identify and quantify proteins is hampered by the heterogeneity of file formats at the raw spectral data, peptide identification, and protein identification levels. Different mass spectrometers output their raw spectral data in a variety of proprietary formats, and alternative methods that assign peptides to MS/MS spectra and infer protein identifications from those peptide assignments each write their results in different formats. Here we describe an MS/MS analysis platform, the Trans-Proteomic Pipeline, which makes use of open XML file formats for storage of data at the raw spectral data, peptide, and protein levels. This platform enables uniform analysis and exchange of MS/MS data generated from a variety of different instruments, and assigned peptides using a variety of different database search programs. We demonstrate this by applying the pipeline to data sets generated by ThermoFinnigan LCQ, ABI 4700 MALDI-TOF/TOF, and Waters Q-TOF instruments, and searched in turn using SEQUEST, Mascot, and COMET
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