Reduction of Noise from a Fan Stage for a Turbofan Engine by Use of Long-Chord Acoustically-Treated Stator Vanes

A set of acoustically-treated long-chord vanes was designed to replace the vanes in an existing fan stage to investigate the noise reduction possibilities of both increased stator chord length and a method of incorporating acoustic damping material. The vanes were tested with both active and inactive acoustic surfaces. Results of the inactive tests show significant broadband noise effects with noise reductions in the middle to high frequencies and an increase at low frequencies. No reduction in blade passage tone was observed, but decreases in the overtones were observed. Results of the tests with the active acoustic treatment show large noise reductions over a wide frequency range

Effects of long-chord acoustically treated stator vanes on fan noise. 1: Effect of long chord (taped stator)

A set of long-chord stator vanes was designed to replace the vanes in an existing fan stage. The long vanes consisted of a turning section and axial extension pieces, both of which incorporated acoustic damping material. The acoustic damping material was made inactive for these tests by covering with metal tape, and the stator vanes were tested in three length configurations. Compared to the values for the original stage, broadband noise was reduced in the middle to high frequencies with the long stator vanes, but a broadband noise increase was observed at the low frequencies. No change was observed in the blade passage tone, but some aft end reduction in the overtones was observed

Effects of long-chord acoustically treated stator vanes on fan noise. 2: Effect of acoustical treatment

A set of long chord stator vanes was designed to replace the vanes in an existing fan stage. The long chord stator vanes consisted of a turning section and axial extension pieces, all of which incorporated acoustic damping material. The long chord stator vanes were tested in two lengths, with the long version giving more noise reduction than the short, primarily because of the additional lining material. The noise reduction achieved with the acoustically treated long chord stator vanes was compared with the reduction achieved by an acoustically treated exhaust splitter. The long chord stator was at least as good as the splitter as a method for incorporating acoustic lining material. In addition, comparing an acoustic three ring inlet and an acoustic wall-only inlet discloses that the wall-only inlet could be used in an engine where the noise reduction requirements are not too stringent

Towards a Precise Parton Luminosity Determination at the CERN LHC

A new approach to determine the LHC luminosity is investigated. Instead of employing the proton-proton luminosity measurement, we suggest to measure directly the parton-parton luminosity. It is shown that the electron and muon pseudorapidity distributions, originating from the decay of W+, W- and Z0 bosons produced at 14 TeV pp collisions (LHC), constrain the x distributions of sea and valence quarks and antiquarks in the range from about 3 x 10**-4 to about 10**-1 at a Q**2 of about 10**4 GeV**2. Furthermore, it is demonstrated that, once the quark and antiquark structure functions are constrained from the W+,W- and Z0 production dynamics, other quark-antiquark related scattering processes at the LHC like q-qbar --> W+W- can be predicted accurately. Thus, the lepton pseudorapidity distributions provide the key to a precise parton luminosity monitor at the LHC, with accuracies of about +-1% compared to the so far considered goal of +-5%.Comment: plain tex, 14 pages, 5 figure

Evaluation of the Impact of an Antibiotic Time-out for Transition of IV Vancomycin to Oral Linezolid in Hospitalized Patients

Background: Oral linezolid is a broad-spectrum oxazolidinone antibiotic that offers advantages compared to intravenous (IV) vancomycin including no requirement for therapeutic drug monitoring, no need for home health or peripherally inserted central catheter (PICC) line placement, and opportunities for earlier hospital discharge due to the ease of continuing therapy outpatient. A medication use evaluation investigated if opportunities existed for oral linezolid over IV vancomycin among a randomized cohort of 100 patients initiated on IV vancomycin. Reviewers identified 15 patients who were candidates for transition to oral linezolid and calculated a potential cost avoidance of $125 per day of antibiotic therapy. The purpose of this study is to assess the feasibility of implementing an interdisciplinary approach for transitioning IV vancomycin to oral linezolid based on pharmacist-led transition criteria. Methods: This is an IRB-reviewed, single-center, quasi-experimental study at Baptist Hospital of Miami, a 900-bed tertiary community hospital. Included patients were \u3e18 years old, receiving IV vancomycin for \u3e48 hours, and admitted between January 10, 2023 and March 31, 2023. Patients were excluded if they had an active vasopressor order, were immunocompromised, or if the patient was receiving antibiotics for meningitis, endocarditis, febrile neutropenia, or surgical prophylaxis. A pharmacy resident was on-call to assess for oral linezolid candidates using antibiotic timeout criteria and intervened as appropriate. Continuous and categorical variables were evaluated using the Mann-Whitney U test and Fisher’s exact test, respectively. The primary outcome was total cost avoidance in patients transitioned from IV vancomycin to oral linezolid. Secondary outcomes included median hospital length of stay, median antibiotic treatment days, and incidence of thrombocytopenia and acute kidney injury, and pharmacist intervention acceptance rate. Results: Investigators screened 317 patients for study inclusion and 94 patients met criteria. 66 (70$5,538, with a total of $21 and$70 saved per inpatient and outpatient antibiotic treatment day, respectively. Median length of antibiotic treatment days was 6 days between both groups (p=0.3524). No statistically significant differences were observed between length of stay, length of antibiotic treatment days, or safety outcomes between the 2 groups. Acute kidney injury occurred in 1 patient receiving linezolid and 1 patient receiving IV vancomycin. Thrombocytopenia, defined as a \u3e50% drop in platelet count from baseline, occurred in 1 patient receiving provider-driven linezolid therapy. Conclusion: Pharmacist-driven transition criteria from IV vancomycin to linezolid therapy resulted in a positive cost avoidance strategy, with similar effect on hospital antibiotic treatment days and no difference in incidence of adverse effects. These results demonstrate the practicality of a pharmacist prospective antibiotic timeout and intervention strategy for patients receiving empiric or targeted Methicillin-resistant Staphylococcus aureus (MRSA) therapy

Assessment of a Pharmacist-Led Antibiotic Time-out for Transition of IV Vancomycin to Oral Linezolid

Introduction: Intravenous (IV) vancomycin requires therapeutic drug monitoring and line placement and may prolong hospital stay. Linezolid requires less monitoring, is orally bioavailable, and may expedite transitions of care. This study assessed the impact of a pharmacist-led antibiotic timeout for the transition from IV vancomycin to oral linezolid. Methods: This single-center, quasi-experimental study included admitted adult patients receiving IV vancomycin for over 48 hours. Patients receiving vasopressors, of immunocompromised status, or with specific antibiotic indications were excluded. The primary outcome was the pharmacist intervention acceptance rate. Secondary outcomes included median hospital length of stay, median antibiotic treatment days, and incidence of adverse effects. Results: Of the 317 screened patients, 94 were eligible for the antibiotic time-out assessment, of which 66 met the criteria for oral linezolid. Of those meeting the criteria, 27 interventions were made, of which 20 (74%) were accepted. The median length of antibiotic treatment days was six days between both groups (p = .352). No differences in safety outcomes were observed. Discussion: A pharmacist-led antibiotic timeout for IV vancomycin to oral linezolid resulted in a high intervention acceptance rate and increased oral linezolid use without impacting safety outcomes. These results support the use of this strategy for antimicrobial stewardship. Conclusion: This study illustrates the impact of a pharmacist-led antibiotic timeout for the transition from IV vancomycin to oral linezolid therapy as an antimicrobial stewardship tool

MicroRNA-34a promotes genomic instability by a broad suppression of genome maintenance mechanisms downstream of the oncogene KSHV-vGPCR

The Kaposi's sarcoma-associated herpesvirus (KSHV)-encoded chemokine receptor vGPCR acts as an oncogene in Kaposi's sarcomagenesis. Until now, the molecular mechanisms by which the vGPCR contributes to tumor development remain incompletely understood. Here, we show that the KSHV-vGPCR contributes to tumor progression through microRNA (miR)-34a-mediated induction of genomic instability. Large-scale analyses on the DNA, gene and protein level of cell lines derived from a mouse model of vGPCR-driven tumorigenesis revealed that a vGPCR-induced upregulation of miR-34a resulted in a broad suppression of genome maintenance genes. A knockdown of either the vGPCR or miR-34a largely restored the expression of these genes and confirmed miR-34a as a downstream effector of the KSHV-vGPCR that compromises genome maintenance mechanisms. This novel, protumorigenic role of miR-34a questions the use of miR-34a mimetics in cancer therapy as they could impair genome stability

H-->WW as the discovery mode for a light Higgs boson

The production cross section for a m_H=115 GeV, SM Higgs boson in weak boson fusion at the LHC is sizable. However, the branching fraction for H-->WW is expected to be relatively small. The signal, with its two forward jets, is sufficiently different from the main backgrounds that a signal to background ratio of better than 1:1 can nevertheless be obtained, with large enough rate to allow for a 5 sigma signal with 35 fb^{-1} of data. The H-->WW signal in weak boson fusion may thus prove to be the discovery mode for the Higgs boson at the LHC.Comment: 10 pages, 4 figures, uses revte