Search

An interval statistical energy method is proposed to calculate the variation range of high-frequency vibration energy for acoustic–vibration coupling systems with uncertain material parameters. Instead of using statistical energy analysis parameters as the uncertainty variables, material physical parameters, with a clearer physical meaning, are used; this is convenient for determining the perturbation interval and avoiding mutual coupling among the uncertain parameters. In this novel method, the derivative matrix of the loss factor matrix with respect to material parameters is derived, and the sensitivity during the uncertain transfer process is obtained analytically. This approach is more accurate than previous numerical methods. Using this interval statistical energy method, numerical examples are calculated and compared with results obtained using the Monte Carlo method, which shows that this method can effectively and accurately calculate the variation range of the system vibration energy under the condition of material uncertainty for structural–acoustic coupling systems. [ABSTRACT FROM AUTHOR]

Background:Sometimes the diagnosis of recurrent cancer in patients with a previous malignancy can be challenging. This prospective cohort study assessed the clinical utility of 18F-fluorodeoxyglucose positron-emission tomography-computed tomography (18F-FDG PET-CT) in the diagnosis of clinically suspected recurrence of cancer.Methods:Patients were eligible if cancer recurrence (non-small-cell lung (NSCL), breast, head and neck, ovarian, oesophageal, Hodgkin's or non-Hodgkin's lymphoma) was suspected clinically, and if conventional imaging was non-diagnostic. Clinicians were asked to indicate their management plan before and after 18F-FDG PET-CT scanning. The primary outcome was change in planned management after 18F-FDG PET-CT.Results:Between April 2009 and June 2011, 101 patients (age, median 65 years; 55% female) were enroled from four cancer centres in Ontario, Canada. Distribution by primary tumour type was: NSCL (55%), breast (19%), ovarian (10%), oesophageal (6%), lymphoma (6%), and head and neck (4%). Of the 99 subjects who underwent 18F-FDG PET-CT, planned management changed after 18F-FDG PET-CT in 52 subjects (53%, 95% confidence interval (CI), 42-63%); a major change in plan from no treatment to treatment was observed in 38 subjects (38%, 95% CI, 29-49%), and was typically associated with 18F-FDG PET-CT findings that were positive for recurrent cancer (37 subjects). After 3 months, the stated post-18F-FDG PET-CT management plan was actually completed in 88 subjects (89%, 95% CI, 81-94%).Conclusion:In patients with suspected cancer recurrence and conventional imaging that is non-diagnostic, 18F-FDG PET-CT often provides new information that leads to important changes in patient management. [ABSTRACT FROM AUTHOR]

In this Letter, a hybrid 10 Gbit/s on-off keying free space optics and passive optical network (FSO-PON) system is proposed and demonstrated. The experimental received sensitivities are -18 and -20 dBm at the back to back (BtB) and after 25 km fibre transmission, respectively, with 5 m free space traffic link. In the proposed analysis, FSO-PON system can support 32 and 16; and 8 and 4 remote optical wireless units for free space communication at BtB and after 25 km fibre link, respectively, when the free space transmission lengths are 150 and 300 m. [ABSTRACT FROM AUTHOR]

The article presents questions and answers related to the risk of fatal pulmonary embolism after discontinuing anticoagulation including its problems, the reasons for its investigation and its limitations.

Background: The post-thrombotic syndrome frequently develops in patients with proximal deep-vein thrombosis despite treatment with anticoagulant therapy. Pharmacomechanical catheter-directed thrombolysis (hereafter "pharmacomechanical thrombolysis") rapidly removes thrombus and is hypothesized to reduce the risk of the post-thrombotic syndrome.Methods: We randomly assigned 692 patients with acute proximal deep-vein thrombosis to receive either anticoagulation alone (control group) or anticoagulation plus pharmacomechanical thrombolysis (catheter-mediated or device-mediated intrathrombus delivery of recombinant tissue plasminogen activator and thrombus aspiration or maceration, with or without stenting). The primary outcome was development of the post-thrombotic syndrome between 6 and 24 months of follow-up.Results: Between 6 and 24 months, there was no significant between-group difference in the percentage of patients with the post-thrombotic syndrome (47% in the pharmacomechanical-thrombolysis group and 48% in the control group; risk ratio, 0.96; 95% confidence interval [CI], 0.82 to 1.11; P=0.56). Pharmacomechanical thrombolysis led to more major bleeding events within 10 days (1.7% vs. 0.3% of patients, P=0.049), but no significant difference in recurrent venous thromboembolism was seen over the 24-month follow-up period (12% in the pharmacomechanical-thrombolysis group and 8% in the control group, P=0.09). Moderate-to-severe post-thrombotic syndrome occurred in 18% of patients in the pharmacomechanical-thrombolysis group versus 24% of those in the control group (risk ratio, 0.73; 95% CI, 0.54 to 0.98; P=0.04). Severity scores for the post-thrombotic syndrome were lower in the pharmacomechanical-thrombolysis group than in the control group at 6, 12, 18, and 24 months of follow-up (P<0.01 for the comparison of the Villalta scores at each time point), but the improvement in quality of life from baseline to 24 months did not differ significantly between the treatment groups.Conclusions: Among patients with acute proximal deep-vein thrombosis, the addition of pharmacomechanical catheter-directed thrombolysis to anticoagulation did not result in a lower risk of the post-thrombotic syndrome but did result in a higher risk of major bleeding. (Funded by the National Heart, Lung, and Blood Institute and others; ATTRACT ClinicalTrials.gov number, NCT00790335 .). [ABSTRACT FROM AUTHOR]

In this study, the nitrate transporter gene CmNRT1 was isolated from the chrysanthemum variety 'Nannongxuefeng'. The full-length cDNA contains an open reading frame of 1761 bp encoding 587 residues. Using qRT-PCR, we found that CmNRT1 was induced by 10 mM NO3(-) in roots and shoots. Two Arabidopsis thaliana transgenic plants expressing CmNRT1 were selected for functional analyses. Root (15)N influx in wild-type and transgenic A. thaliana lines under 10 or 0.2 mM (15)NO3 was tested. Our results indicate that CmNRT1 encodes a constitutive component for a low-affinity transporter.