Artykuły w czasopismach: „LDV”

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van den Broek, M. F., R. Spörri, C. Even, P. G. Plagemann, E. Hänseler, H. Hengartner i R. M. Zinkernagel. "Lactate dehydrogenase-elevating virus (LDV): lifelong coexistence of virus and LDV-specific immunity." Journal of Immunology 159, nr 4 (15.08.1997): 1585–88. http://dx.doi.org/10.4049/jimmunol.159.4.1585.

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Abstract Viruses have developed various strategies to coexist with vertebrate hosts. Lactate dehydrogenase-elevating virus (LDV) is a highly cytopathic virus exhibiting an extraordinary rate of replication; LDV nevertheless establishes a persistent infection without harming the host. The cytotoxic and helper T cell responses to LDV were monitored in mice with different genetic backgrounds. LDV-specific cytotoxic and helper T cells were found in all strains tested. These responses persisted for at least up to 250 days despite high levels of LDV in the blood. Thus, the cytopathic LDV induces and maintains an inefficient immune response that is not exhausted. LDV infection in mice reveals a special type of host-virus equilibrium where LDV quickly establishes persistence despite continuously induced LDV-specific helper and cytotoxic T cell responses, which apparently are too slow to control the highly cytopathic and extremely fast replicating virus.

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Stokes, William, Carol Fenton, Fiona Clement, Matthew James, Paul Ronksley i Karen L. Tang. "The Efficacy and Safety of 12 Weeks of Sofosbuvir and Ledipasvir versus Sofosbuvir, Ledipasvir, and Ribavirin in Patients with Chronic Hepatitis C, Genotype 1, Who Have Cirrhosis and Have Failed Prior Therapy: A Systematic Review and Meta-Analysis". Canadian Journal of Gastroenterology and Hepatology 2017 (2017): 1–8. http://dx.doi.org/10.1155/2017/6468309.

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Background.The recommended therapy for patients with chronic hepatitis C (CHC), genotype 1, who have cirrhosis and have failed prior therapy is 12 weeks of sofosbuvir (SOF), ledipasvir (LDV), and ribavirin (RBV). This recommendation is based on expert opinion, and the efficacy of 12 weeks of SOF/LDV compared to SOF/LDV/RBV in this patient population has not yet been established.Methods. We conducted a systematic review and meta-analysis. Two investigators independently searched electronic databases and relevant conference proceedings for randomized controlled trials comparing rates of sustained virologic response 12 weeks after therapy (SVR12) when using 12 weeks of SOF/LDV versus 12 weeks of SOF/LDV/RBV in patients with CHC, genotype 1, who have cirrhosis and failed previous therapy.Results.Our search strategy yielded 596 studies of which four met criteria for inclusion. The pooled RR of not achieving SVR12 with SOF/LDV versus SOF/LDV/RBV was 1.21 (95% CI: 0.42–3.48). Adverse events were lower in the SOF/LDV compared to the SOF/LDV/RBV arms (pooled RR: 0.11, 95% CI: 0.04–0.29).Conclusions.Our findings suggest that 12 weeks of SOF/LDV cannot be considered noninferior to 12 weeks of SOF/LDV/RBV to achieve SVR12 in patients with CHC who have cirrhosis and failed prior therapy.

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Plagemann, Peter G. W., Quentin A. Jones i William A. Cafruny. "N-Glycans on the short ectodomain of the primary envelope glycoprotein play a major role in the polyclonal activation of B cells by lactate dehydrogenase-elevating virus". Journal of General Virology 81, nr 9 (1.09.2000): 2167–75. http://dx.doi.org/10.1099/0022-1317-81-9-2167.

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The common biologically cloned isolates of lactate dehydrogenase-elevating virus (LDV-P and LDV-vx) invariably cause a polyclonal activation of B cells in immunocompetent mice. It is recognized by an at least 10-fold increase in plasma IgG2a levels and the de novo formation of immune complexes that most likely consist of autoantibodies and their antigens. The present study indicates that three closely spaced N-glycans on the short ectodomain of the primary envelope glycoprotein, VP-3P, of LDV-P/vx, play a major role in inducing the polyclonal proliferation of B cells. IFN-γ then seems to mediate the differentiation of the activated B cells to IgG2a-producing plasma cells. These conclusions are based on the finding that the IgG2a hypergammaglobulinaemia and immune complex formation were much lower in mice that were infected with LDV variants (LDV-C and LDV-v) whose VP-3P ectodomains lack two of the three N-glycans than in LDV-P/vx infected mice. In contrast, the VP-3P ectodomains of three neutralization escape variants of LDV-C/v whose VP-3P ectodomains possess three N-glycosylation sites caused a polyclonal activation of B cells comparable to that of LDV-P/vx.

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Kiel, J. W., G. L. Riedel, G. R. DiResta i A. P. Shepherd. "Gastric mucosal blood flow measured by laser-Doppler velocimetry". American Journal of Physiology-Gastrointestinal and Liver Physiology 249, nr 4 (1.10.1985): G539—G545. http://dx.doi.org/10.1152/ajpgi.1985.249.4.g539.

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To determine the feasibility of measuring gastric mucosal blood flow by laser-Doppler velocimetry (LDV), we utilized two LDV flowmeters to monitor blood flow in mucosa and serosa of chambered canine stomach. In isolated, nonautoregulating gastric segments vasodilated with isoproterenol, LDV mucosal and muscularis blood flows were both linearly related to total electromagnetic blood flow during step increases in perfusion pressure. To assess the depth of the LDV measurement, we recorded reactive hyperemia following arterial occlusion. Reactive hyperemia was frequently registered in the mucosa but rarely in muscularis. Placing a layer of nonperfused mucosa-submucosa between the probe and the perfused mucosa abolished the resting LDV mucosal flow signal and attenuated the recording of peak hyperemia by 85%. Furthermore, intra-arterial infusions of both adenosine and isoproterenol frequently increased LDV mucosal flow and decreased LDV muscularis flow, although total flow was consistently increased. These findings indicate that our LDV instruments yield linear, superficial measurements of gastric blood flow in either mucosa or muscularis. Although calibration in absolute units remains to be achieved, our results demonstrate that LDV is a practical means of studying the gastric mucosal microcirculation.

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Arechvo, Irina, Nikoloz Lasurashvili, Matthias Bornitz, Zurab Kevanishvili i Thomas Zahnert. "Laser Doppler vibrometry of the middle ear in humans: derivation dependence, variability, and bilateral differences". Medicina 45, nr 11 (11.11.2009): 878. http://dx.doi.org/10.3390/medicina45110113.

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Objective. Derivation dependence, inter- and intrasubject/intertest variability, bilateral differences of the eardrum vibration characteristics have been investigated using laser Doppler vibrometry (LDV). Material and methods. A total of 31 normally hearing adults were examined. In each subject, both ears were consecutively stimulated by the chirp acoustic stimulus that covered 500–3700-Hz frequencies. The laser beam was directed to and the reflection was consecutively picked up from the tympanic membrane surface. Results. LDV curves derived from different eardrum loci possessed dissimilar characteristics. The derivation area dependence was particularly apparent for the stimulus frequency constituents above 1500 Hz. The intersubject variability of LDV parameters exceeded the intrasubject/ intertest one. The intersubject divergences looked selectively distinct for the frequencies over 2000 Hz. Under repeated recordings, LDV parameters remained stable. The intertest differences, if appeared, concerned predominantly the magnitudes of separate frequency bands. LDV waveforms registered by experienced and beginner investigators were alike. Bilaterally derived LDV curves regularly differed from each other. In individual cases, the bilateral divergences approximated the intersubject deviation. Conclusions. The derivation area on the eardrum should be taken into account when estimating the actual LDV recording. Over repeated recordings in separate individuals, LDV waveforms are stable while the experience of investigator has slight if any influence on the principal LDV characteristics. Due to bilateral differences in the middle ear transfer function, in LDV testing of the ear suspected to the pathology, LDV recording from the opposite healthy ear could hardly be taken as an appropriate reference sample.

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Cheng, Guofeng, Yang Tian, Brian Doehle, Betty Peng, Amoreena Corsa, Yu-Jen Lee, Ruoyu Gong i in. "In VitroAntiviral Activity and Resistance Profile Characterization of the Hepatitis C Virus NS5A Inhibitor Ledipasvir". Antimicrobial Agents and Chemotherapy 60, nr 3 (11.01.2016): 1847–53. http://dx.doi.org/10.1128/aac.02524-15.

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Ledipasvir (LDV; GS-5885), a component of Harvoni (a fixed-dose combination of LDV with sofosbuvir [SOF]), is approved to treat chronic hepatitis C virus (HCV) infection. Here, we report key preclinical antiviral properties of LDV, includingin vitropotency,in vitroresistance profile, and activity in combination with other anti-HCV agents. LDV has picomolar antiviral activity against genotype 1a and genotype 1b replicons with 50% effective concentration (EC50) values of 0.031 nM and 0.004 nM, respectively. LDV is also active against HCV genotypes 4a, 4d, 5a, and 6a with EC50values of 0.11 to 1.1 nM. LDV has relatively lessin vitroantiviral activity against genotypes 2a, 2b, 3a, and 6e, with EC50values of 16 to 530 nM.In vitroresistance selection with LDV identified the single Y93H and Q30E resistance-associated variants (RAVs) in the NS5A gene; these RAVs were also observed in patients after a 3-day monotherapy treatment.In vitroantiviral combination studies indicate that LDV has additive to moderately synergistic antiviral activity when combined with other classes of HCV direct-acting antiviral (DAA) agents, including NS3/4A protease inhibitors and the nucleotide NS5B polymerase inhibitor SOF. Furthermore, LDV is active against known NS3 protease and NS5B polymerase inhibitor RAVs with EC50values equivalent to those for the wild type.

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Li, Yanlu, Emiel Dieussaert i Roel Baets. "Miniaturization of Laser Doppler Vibrometers—A Review". Sensors 22, nr 13 (23.06.2022): 4735. http://dx.doi.org/10.3390/s22134735.

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Laser Doppler vibrometry (LDV) is a non-contact vibration measurement technique based on the Doppler effect of the reflected laser beam. Thanks to its feature of high resolution and flexibility, LDV has been used in many different fields today. The miniaturization of the LDV systems is one important development direction for the current LDV systems that can enable many new applications. In this paper, we will review the state-of-the-art method on LDV miniaturization. Systems based on three miniaturization techniques will be discussed: photonic integrated circuit (PIC), self-mixing, and micro-electrochemical systems (MEMS). We will explain the basics of these techniques and summarize the reported miniaturized LDV systems. The advantages and disadvantages of these techniques will also be compared and discussed.

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Robertson, Shelly J., Christoph G. Ammann, Ronald J. Messer, Aaron B. Carmody, Lara Myers, Ulf Dittmer, Savita Nair i in. "Suppression of Acute Anti-Friend Virus CD8+ T-Cell Responses by Coinfection with Lactate Dehydrogenase-Elevating Virus". Journal of Virology 82, nr 1 (24.10.2007): 408–18. http://dx.doi.org/10.1128/jvi.01413-07.

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ABSTRACT Friend virus (FV) and lactate dehydrogenase-elevating virus (LDV) are endemic mouse viruses that can cause long-term chronic infections in mice. We found that numerous mouse-passaged FV isolates also contained LDV and that coinfection with LDV delayed FV-specific CD8+ T-cell responses during acute infection. While LDV did not alter the type of acute pathology induced by FV, which was severe splenomegaly caused by erythroproliferation, the immunosuppression mediated by LDV increased both the severity and the duration of FV infection. Compared to mice infected with FV alone, those coinfected with both FV and LDV had delayed CD8+ T-cell responses, as measured by FV-specific tetramers. This delayed response accounted for the prolonged and exacerbated acute phase of FV infection. Suppression of FV-specific CD8+ T-cell responses occurred not only in mice infected concomitantly with LDV but also in mice chronically infected with LDV 8 weeks prior to infection with FV. The LDV-induced suppression was not mediated by T regulatory cells, and no inhibition of the CD4+ T-cell or antibody responses was observed. Considering that most human adults are carriers of chronically infectious viruses at the time of new virus insults and that coinfections with viruses such as human immunodeficiency virus and hepatitis C virus are currently epidemic, it is of great interest to determine how infection with one virus may impact host responses to a second infection. Coinfection of mice with LDV and FV provides a well-defined, natural host model for such studies.

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Luchins, Kerith R., Darya Mailhiot, Betty R. Theriault i George P. Langan. "Detection of Lactate Dehydrogenase Elevating Virus in a Mouse Vivarium Using an Exhaust Air Dust Health Monitoring Program". Journal of the American Association for Laboratory Animal Science 59, nr 3 (1.05.2020): 328–33. http://dx.doi.org/10.30802/aalas-jaalas-19-000107.

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Lactate dehydrogenase elevating virus (LDV) continues to be one of the most common contaminants of cells and cell byproducts. As such, many institutions require that tumor cell lines, blood products, and products derived or passaged in rodent tissues are free of LDV as well as other pathogens that are on institutional exclusion lists prior to their use in rodents. LDV is difficult to detect by using a live-animal sentinel health monitoring program because the virus does not reliably pass to sentinel animals. After switching to an exhaust air dust health monitoring system, our animal resources center was able to detect a presumably long-standing LDV infection in a mouse colony. This health monitoring system uses IVC rack exhaust air dust collection media in conjunction with PCR analysis. Ultimately, the source of the contamination was identified as multiple LDV-positive patient-derived xenografts and multiple LDV-positive breeding animals. This case study is the first to demonstrate the use of environmental PCR testing as a method for detecting LDV infection in a mouse vivarium.

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Casadevall, M., J. Panes, J. M. Pique, J. Bosch, J. Teres i J. Rodes. "Limitations of laser-Doppler velocimetry and reflectance spectrophotometry in estimating gastric mucosal blood flow". American Journal of Physiology-Gastrointestinal and Liver Physiology 263, nr 5 (1.11.1992): G810—G815. http://dx.doi.org/10.1152/ajpgi.1992.263.5.g810.

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This study investigated the accuracy of laser-Doppler flowmetry (LDV) and reflectance spectrophotometry (RS) measurements as an index of blood flow in the gastric mucosa of the rat, in experimental conditions such as pharmacologically induced vasoconstriction, hypoxia, hyperoxia, and acute normovolemic anemia. Hydrogen gas clearance was used as a reference method. After vasopressin infusion, LDV signal and indexes of hemoglobin (IHb) and oxygen (ISO2) content in the gastric mucosa estimated by RS significantly decreased in parallel with the reduction of gastric mucosal blood flow (GMBF). Neither hypoxia (5% O2 administration) nor hyperoxia (100% O2) affected GMBF or LDV signal. However, both IHb and ISO2 significantly decreased or increased after hypoxia or hyperoxia, respectively. Acute normovolemic anemia induced a significant increase in GMBF, while LDV signal and ISO2 remained unchanged. IHb significantly decreased in linear relationship with the decrements in the hematocrit. It is concluded that 1) in pharmacologically induced GMBF changes, LDV and RS correlate with GMBF; 2) when changes in hemoglobin saturation are induced, LDV but not RS reflects GMBF; and 3) in acute normovolemic anemia, neither LDV nor RS reflects changes in GMBF.

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Yonemura, Shinji, Lin Zhou i Frank E. Talke. "An Investigation of Slider Vibrations in Near Contact Recording Using a Digital Laser Doppler Vibrometer". Journal of Tribology 125, nr 3 (19.06.2003): 571–75. http://dx.doi.org/10.1115/1.1540124.

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At a flying height of 10 nanometers, contacts between slider and disk are likely to occur, and control of contact-induced slider vibrations is an important design consideration. In this study, slider vibrations during contact are investigated using a digital laser Doppler vibrometer (LDV). The noise level of the digital interferometer is compared with that of a conventional analog LDV. In addition, acoustic emission (AE) sensors are used to evaluate the contact behavior of the slider. A comparison of AE and LDV data is performed. The results show that the noise level of the digital LDV is lower than that of the analog LDV, and that suspension sway mode vibrations and torsion mode vibrations are excited during contact as a function of the skew angle.

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Kvietys, P. R., A. P. Shepherd i D. N. Granger. "Laser-Doppler, H2 clearance, and microsphere estimates of mucosal blood flow". American Journal of Physiology-Gastrointestinal and Liver Physiology 249, nr 2 (1.08.1985): G221—G227. http://dx.doi.org/10.1152/ajpgi.1985.249.2.g221.

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In autoperfused preparations of feline jejunum, blood flow was measured from the mucosal surface with laser-Doppler velocimetry (LDV) and hydrogen gas (H2) clearance techniques while blood flow was altered by intra-arterial infusions of isoproterenol. LDV and H2 clearance estimates of blood flow were compared with total-wall and mucosal-submucosal blood flows measured with the radiolabeled microsphere technique. Over the range (26.3–73.6 ml X min-1 X 100 g-1) of blood flows attained, a series of direct linear relationships were obtained among LDV, H2 clearance, and microsphere estimates of jejunal blood flow. The slopes of these relationships indicated that the H2 clearance technique over-estimates total intestinal blood flow but reflects mucosal-submucosal flow as measured with microspheres. LDV measurements of blood flow from the mucosal surface were equally well correlated with total and mucosal-submucosal blood flow measured by microspheres, thereby not allowing for a definitive conclusion on the measurement depth of the LDV method. However, the ability of the LDV method to detect changes in blood flow in the perfused gut, even through 3 mm of unperfused tissue, casts a doubt on the assumption that the LDV method has a spatial resolution of less than 0.5–1.0 mm. The results of this study indicate that the H2 clearance technique can be used to measure mucosal blood flow in the small intestine. By contrast, the precise measurement depth of the LDV method is still uncertain and requires further evaluation.

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van den Broek, Maries F., Roman Spörri, Chen Even, Peter G. W. Plagemann, Edgar Hänseler, Hans Hengartner i Rolf M. Zinkemagel. "Lactate dehydrogenase-elevating virus (LDV): Lifelong coexistence of virus and LDV-specific immunity". Immunology Letters 56 (maj 1997): 300. http://dx.doi.org/10.1016/s0165-2478(97)86210-4.

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van den Broek, M. "Lactate dehydrogenase-elevating virus (LDV): Lifelong coexistence of virus and LDV-specific immunity". Immunology Letters 56, nr 1-3 (maj 1997): 300. http://dx.doi.org/10.1016/s0165-2478(97)88048-0.

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Hasheminejad, Navid, Cedric Vuye, Wim Van den bergh, Joris Dirckx i Steve Vanlanduit. "A Comparative Study of Laser Doppler Vibrometers for Vibration Measurements on Pavement Materials". Infrastructures 3, nr 4 (1.11.2018): 47. http://dx.doi.org/10.3390/infrastructures3040047.

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A laser Doppler vibrometer (LDV) is a noncontact optical measurement device to measure the vibration velocities of particular points on the surface of an object. Even though LDV has become more popular in road engineering in recent years, their signal-to-noise ratio (SNR) is strongly dependent on light scattering properties of the surface which, in some cases, needs to be properly conditioned. SNR is the main limitation in LDV instrumentation when measuring on low diffusive surfaces like pavements; therefore, an investigation on the SNR of different LDV devices on different surface conditions is of great importance. The objective of this research is to investigate the quality of two types of commercially available LDV systems—helium–neon (He–Ne)-based vibrometers and recently developed infrared vibrometers—on different surface conditions, i.e., retroreflective tape, white tape, black tape, and asphalt concrete. Both noise floor and modal analysis experiments are carried out on these surface conditions. It is shown that the noise floor of the He–Ne LDV is higher when dealing with a noncooperative dark surface, such as asphalt concrete, and it can be improved by improving the surface quality or by using an infrared LDV, which consequently improves the modal analysis experiments performed on pavement materials.

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Huynh, Linh Quang, Hieu Sy Dau, Tien Van Tran i Long Ba Chu. "LASER DOPPLER VELOCITY MEASUREMENT SYSTEM". Science and Technology Development Journal 13, nr 4 (30.12.2010): 84–90. http://dx.doi.org/10.32508/stdj.v13i4.2180.

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Laser Doppler Velocimetry technique (LDV) isa measuring technique which has been developed since early 1980s. LDV has many advantages such as non-invasive measurement of one or all three components of velocity vector, measured dimensional vector of velocity, high accuracy, high resolution, wide measurement range ... Commercial Equipment based on LDV principle was applied to measure flow in industrial applications, in biomedical applications, etc. ... However, most of them are the specialized equipment which have high cost. In terms of technical training and education, LDV experiment is one of the basic experiments of application in high-tech optical measuring techniques, showing the skills of application of the principle of optical measurement applications in practical conditions. A model LDV system was designed and complete development within the lab for training purposes.

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Hawkins, Kelsey L., i Ives Hot. "Retrospective Cohort Study: Ledipasvir-Sofosbuvir With/Without Ribavirin for Chronic Hepatitis C Post–Liver Transplant in a Real-World Population". Journal of Pharmacy Technology 34, nr 5 (20.06.2018): 199–203. http://dx.doi.org/10.1177/8755122518782478.

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Background: Liver damage caused by hepatitis C virus (HCV) is the number one indication for liver transplantation in the United States and Europe. Patients with a detectable HCV level at time of transplant will universally develop a recurrent infection, which can lead to increased morbidity and mortality. Objective: To assess the sustained virologic response rate post end-of-treatment (SVR) in HCV-infected, post–liver transplant patients at the University of Washington Medical Center (UWMC) treated with ledipasvir-sofosbuvir (LDV/SOF). Methods: This retrospective, cohort study of HCV-positive, genotype 1 or 4 infected, post–liver transplant patients treated with LDV/SOF was conducted at a large academic medical center affiliated clinic. Patients treated with 12 weeks of LDV/SOF with or without ribavirin were included in the 12-week group, and patients treated with 24 weeks of LDV/SOF without ribavirin were included in the 24-week group. Results: Twenty-nine patients with recurrent HCV post–liver transplant receiving 12 weeks of LDV/SOF with or without ribavirin and 32 patients receiving 24 weeks of LDV/SOF alone were assessed. SVR was achieved by 100% (29/29) of patients in the 12-week group and 100% (32/32) of patients in the 24-week group. Conclusion: Post–liver transplant patients at UWMC treated with LDV/SOF for recurrent HCV achieved high rates of SVR.

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Wang, Mengmeng, Fengju Zhang, Christine Carole Copruz i Longhui Han. "First Experience in Small Incision Lenticule Extraction with the Femto LDV Z8 and Lenticule Evaluation Using Scanning Electron Microscopy". Journal of Ophthalmology 2020 (26.09.2020): 1–8. http://dx.doi.org/10.1155/2020/6751826.

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Purpose. To evaluate the specifications and technique properties of the new Femto LDV Z8 in creating intrastromal refractive lenticules during small incision lenticule extraction (SMILE). Methods. Six enucleated porcine eyeballs were equally divided into two groups (Femto LDV Z8 or VisuMax) and were randomly assigned to three experienced refractive surgeons who performed SMILE on each group. Five intraoperative time parameters and surgeons’ satisfaction on the surgical procedure were compared between two groups. Postoperatively, the roughness of the lenticule surfaces and the irregularity of edges were observed by scanning electron microscopy (SEM) and were also compared between the two groups. Results. Longer time on suction peak pressure, total laser application, and total surgery were spent in the Femto LDV Z8 group as compared with the VisuMax group. The Femto LDV Z8 group applied OCT scanning and offsetting before performing the laser procedure, which expended more time for these crucial steps. The widest range of surgeons’ satisfaction scores was found in the step of lenticule interface identification of the Femto LDV Z8 group. The roughness scores of the anterior and posterior lenticule surfaces were statistically less in the Femto LDV Z8 group than in the VisuMax group (anterior, ×180, p=0.039; anterior, ×250, p=0.337; posterior, ×180, p=0.006; and posterior, ×250, p=0.007). Conclusions. Femto LDV Z8 showed promising performances as a novel SMILE equipment for the correction of myopia. It has special and unique features for SMILE procedures, which need more learning and researching processes. With its low-energy high-frequency nJ-level laser system, the Femto LDV Z8 provided smoother lenticule surface than VisuMax.

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Maru, Koichi, i Yusaku Fujii. "Laser Doppler Velocimetry Using Integrated Waveguide Technology". Applied Mechanics and Materials 36 (październik 2010): 323–28. http://dx.doi.org/10.4028/www.scientific.net/amm.36.323.

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Integrated laser Doppler velocimeters (LDVs) using integrated waveguide technology are reviewed. LDVs have been widely used to measure the velocity of a fluid flow or rigid object in various research and industries. However, bulk optical systems used in conventional measurement need special care from temperature change and vibration, which become the expected sources of uncertainty in measurement, due to large optical path length. Therefore, the optical system should be more compact. The LDV can be drastically reduced by using a planar lightwave circuit (PLC). The possibility for realizing several types of novel integrated LDVs, including a wavelength-insensitive LDV, a scanning LDV and a multi-point LDV, is discussed.

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Sitte, B., i C. Egbers. "LDV-measurements on baroclinic waves". Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere 24, nr 5 (styczeń 1999): 473–76. http://dx.doi.org/10.1016/s1464-1909(99)00031-3.

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Bischoff, Martin. "LDV/SOF im Praxistest erfolgreich". MMW - Fortschritte der Medizin 158, S2 (czerwiec 2016): 62. http://dx.doi.org/10.1007/s15006-016-8334-6.

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Tirabassi, Mario, i Steve J. Rothberg. "Scanning LDV using wedge prisms". Optics and Lasers in Engineering 47, nr 3-4 (marzec 2009): 454–60. http://dx.doi.org/10.1016/j.optlaseng.2008.06.003.

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Markine-Goriaynoff, Dominique, Xavier Hulhoven, César L. Cambiaso, Philippe Monteyne, Thérèse Briet, Maria-Dolores Gonzalez, Pierre Coulie i Jean-Paul Coutelier. "Natural killer cell activation after infection with lactate dehydrogenase-elevating virus". Journal of General Virology 83, nr 11 (1.11.2002): 2709–16. http://dx.doi.org/10.1099/0022-1317-83-11-2709.

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Early after infection, lactate dehydrogenase-elevating virus (LDV) alters the immune system by polyclonally activating B lymphocytes, which leads to IgG2a-restricted hypergammaglobulinaemia, and by suppressing the secretion of Th2 cytokines. Considering that these alterations may involve cells of the innate immune system and cytokines such as interferon-gamma (IFN-γ), we analysed the effect of LDV on natural killer (NK) cells. Within a few days of infection, a strong and transient NK cell activation, characterized by enhanced IFN-γ message expression and cytolysis, was observed. LDV triggered a large increase in serum IFN-γ levels. Because NK cells and IFN-γ may participate in the defence against virus infection, we analysed their possible role in the control of LDV titres with a new agglutination assay. Our results indicate that neither the activation of NK cells nor the IFN-γ secretion affect the early and rapid virus replication that follows LDV inoculation.

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Antognoli, Luca, Sara Moccia, Lucia Migliorelli, Sara Casaccia, Lorenzo Scalise i Emanuele Frontoni. "Heartbeat Detection by Laser Doppler Vibrometry and Machine Learning". Sensors 20, nr 18 (18.09.2020): 5362. http://dx.doi.org/10.3390/s20185362.

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Background: Heartbeat detection is a crucial step in several clinical fields. Laser Doppler Vibrometer (LDV) is a promising non-contact measurement for heartbeat detection. The aim of this work is to assess whether machine learning can be used for detecting heartbeat from the carotid LDV signal. Methods: The performances of Support Vector Machine (SVM), Decision Tree (DT), Random Forest (RF) and K-Nearest Neighbor (KNN) were compared using the leave-one-subject-out cross-validation as the testing protocol in an LDV dataset collected from 28 subjects. The classification was conducted on LDV signal windows, which were labeled as beat, if containing a beat, or no-beat, otherwise. The labeling procedure was performed using electrocardiography as the gold standard. Results: For the beat class, the f1-score (f1) values were 0.93, 0.93, 0.95, 0.96 for RF, DT, KNN and SVM, respectively. No statistical differences were found between the classifiers. When testing the SVM on the full-length (10 min long) LDV signals, to simulate a real-world application, we achieved a median macro-f1 of 0.76. Conclusions: Using machine learning for heartbeat detection from carotid LDV signals showed encouraging results, representing a promising step in the field of contactless cardiovascular signal analysis.

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Even, C., i P. G. Plagemann. "Pseudotype virions formed between mouse hepatitis virus and lactate dehydrogenase-elevating virus (LDV) mediate LDV replication in cells resistant to infection by LDV virions." Journal of virology 69, nr 7 (1995): 4237–44. http://dx.doi.org/10.1128/jvi.69.7.4237-4244.1995.

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Doga, A. V., I. A. Mushkova, A. N. Karimova i E. V. Kechin. "In Vivo Histomorphologic Structure of Cornea after FemtoLASIK Using Various Femtosecond Laser Systems". Ophthalmology in Russia 15, nr 3 (5.10.2018): 264–72. http://dx.doi.org/10.18008/1816-5095-2018-3-264-272.

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Purpose:to compare in vivo histomorphologic structure of cornea after the FemtoLASIK procedure using femtolaser systems Femto Visum (Russia) and Femto LDV Z6 (Switzerland).Patients and methods:The study was carried for 70 eyes from 70 patients with low to moderate myopia after FemtoLASIK procedure. Group 1 (Femto Visum) included 36 eyes (n = 36) there the flap were formed using femtolaser Femto Visum («Optosystems», Russia), group 2 (Femto LDV Z6) included 34 eyes (n = 34) and Femto LDV Z6 was used («Ziemer Ophthalmic Systems AG», Switzerland). The excimer laser ablation was performed with Microscan Visum system («Optosystems», Russia) in both groups. The Femto Visum and Femto LDV Z6 groups were comparable in terms of pre-operative data (age, sex, corneal curvature, central corneal thickness, sphere, cylinder, spherical equivalent) (p > 0.05). In vivo histomorphological structure of the cornea was examined using confocal microscope Confoscan 4 (Nidek, Japan) 1 week, 1, 3, 6, and 12 months after FemtoLASIK. The endothelial cell density (ECD) was measured with endothelial microscope (EM-3000, Tomey, Japan) before surgery and 12 months after FemtoLASIK.Results:The main in vivo histomorphological cornea changes occurred in the anterior and middle layers of the corneal stroma during post-operative period in both groups (Femto Visum and Femto LDV Z6). The underlying corneal structures remained intact. There was no statistically significant difference between the two groups (p > 0.05). Twelve months postoperatively, the loss of ECD was 0.31 % in the Femto Visum group and 0.33 % in the Femto LDV Z6 group (p > 0,05).Conclusions:FemtoLASIK procedures using Femto Visum (Russia) and Femto LDV Z6 (Switzerland) lead to similar histomorphological cornea changes in post-operative period (p > 0.05) and they are safe for corneal structure in the treatment of myopia.

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Rau, Mark, Julius O. Smith i Doug L. James. "Augmenting a single-point laser Doppler vibrometer to perform scanning measurements". Journal of the Acoustical Society of America 151, nr 4 (kwiecień 2022): A157. http://dx.doi.org/10.1121/10.0010962.

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Laser Doppler vibrometers (LDV) are used for non-contact vibration measurements of various structures and are frequently used for stringed instrument measurements. Single-point LDVs can be used with the roving hammer or LDV method for mode shape measurements, but this is time-consuming and requires constant attention. Scanning LDVs exist but are expensive and often out of reach of musical acoustics researchers. An inexpensive apparatus to modify a common single-point LDV such that it can perform automated scanning measurements is presented. The augmentation consists of a mirror galvanometer, impact hammer controller, and 3D printed mounting hardware. The scanning system is controlled by a microprocessor and can be easily automated. The total cost of the system, excluding the LDV and impact hammer, is under two hundred dollars. Measurements of guitars are presented to validate the scanning system and discuss any shortcomings.

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Schewe, M., M. A. A. Ismail i C. Rembe. "Towards airborne laser Doppler vibrometry for structural health monitoring of large and curved structures". Insight - Non-Destructive Testing and Condition Monitoring 63, nr 5 (1.05.2021): 280–82. http://dx.doi.org/10.1784/insi.2021.63.5.280.

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Laser Doppler vibrometry is an important sensing technology for many structural health monitoring (SHM) methods, such as modal analysis. However, when it comes to large civil structures, for example historic structures and bridges, the applicability of laser Doppler vibrometry is significantly constrained by inaccessible remote surfaces. Some of these surfaces are fully inaccessible to a ground-mounted laser Doppler vibrometer (LDV), while others are partially inaccessible, and measurements are only possible for low incident angles. Consequently, LDV measurements are either impossible or have a weak signal strength. In this study, the concept of constructing an airborne LDV for SHM is explored, including the examination of a recently developed mechanism, the partially airborne LDV, comprising a reflective mirror attached to a drone. Preliminary proof of concept laboratory tests have been successfully conducted using two different set-ups and drone models.

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Wayner, E. A., i N. L. Kovach. "Activation-dependent recognition by hematopoietic cells of the LDV sequence in the V region of fibronectin." Journal of Cell Biology 116, nr 2 (15.01.1992): 489–97. http://dx.doi.org/10.1083/jcb.116.2.489.

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It has been shown that the alpha 4 beta 1 integrin is the lymphocyte receptor for the carboxy terminal cell-binding domain of fibronectin which comprises adhesion sites in Hep 2 and a high affinity site, CS-1, in the type III connecting segment or V (for variable) region. In the present studies, using a series of peptides derived from CS-1, we identify the tripeptide leu-asp-val (LDV), as the minimal peptide capable of supporting stable lymphocyte or melanoma cell adhesion. However, only cells which expressed an active form of the alpha 4 beta 1 complex were capable of attaching to and spreading on LDV peptide. On a molar basis, LDV minimal peptides were either not active or 10-20 times less active than intact CS-1 in promoting the adhesion of lymphocytes expressing the resting form of the receptor. In cells which express the high avidity form of the receptor, LDV and CS-1 were equally effective in promoting cell adhesion and spreading. The avidity of the alpha 4 beta 1 complex could be altered with mAbs to beta 1 which specifically activate beta 1 dependent function. The high avidity form of the alpha 4 beta 1 complex could be induced on U937 cells, T, and B lymphoblastoid cell lines, or PHA-stimulated T cell blasts. Resting PBL could not be induced to bind LDV peptide conjugates by activating antibodies to beta 1 implying that two signals are required for LDV recognition by T cells. In conclusion, these data show clearly that the minimal peptide for the alpha 4 beta 1 complex in CS-1 is the LDV sequence. Although numerous cell populations can interact with intact CS-1 only cells which express an active alpha 4 beta 1 complex can bind the LDV sequence. This implies that cell interaction with the carboxy terminal cell-binding domain of fibronectin can be regulated at several levels: (a) alpha 4 beta 1 expression; (b) activation of the alpha 4 beta 1 complex; and (c) alternate splicing of CS-1 into V+ isoforms of fibronectin.

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Tanishima, K., T. Hayashi, M. Matsushima i Y. Mochikawa. "Activity of lactate dehydrogenase isoenzymes LD1 and LD2 in serum as determined by using an inhibitor of the M-subunit." Clinical Chemistry 31, nr 7 (1.07.1985): 1175–77. http://dx.doi.org/10.1093/clinchem/31.7.1175.

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Abstract To measure activities of lactate dehydrogenase (EC 1.1.1.27) isoenzymes LD1 and LD2 in serum, we developed a method involving 1,6-hexanediol as specific inhibitor of the M-subunit. Addition of hexanediol, 0.6 mol/L, to five LD isoenzyme fractions purified from human liver and heart homogenates resulted in complete loss of activities of LD4 and LD5, and partial loss of LD2 and LD3. The activity of LD1, which is composed of the H-subunit only, was not affected. In studying what conditions would allow only the activities of LD1 or LD1 + LD2 to be expressed in serum, we found that the respective activities could be determined by treatment with hexanediol, 0.75 mol/L and 0.55 mol/L, respectively. Results of binding experiments and analytical-recovery tests supported the effectiveness of analyses with this inhibitor in determination of LD1 and LD1 + LD2 activities in serum. Results by this proposed inhibition method correlated well with those by the conventional electrophoretic method for determination of LD1 activity, but LD1 + LD2 activities by the inhibition method were a little less than those by the electrophoretic method, requiring some correction.

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Kislovskiy, Yasaswi, Catherine Chappell, Emily Flaherty, Megan E. Hamm, Flor de Abril Cameron, Elizabeth E. Krans i Judy C. Chang. "Experiences and Perspectives From Women Taking Investigational Therapy for Hepatitis C Virus During Pregnancy". Substance Abuse: Research and Treatment 15 (styczeń 2021): 117822182110462. http://dx.doi.org/10.1177/11782218211046261.

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Objective: Describe the experiences and perspectives among pregnant people with chronic HCV infection receiving ledipasvir/sofosbuvir (LDV/SOF) therapy during pregnancy. Methods: We conducted semi-structured, in-depth interviews within an open-label, phase 1 study of LDV/SOF therapy among pregnant people with chronic HCV infection. Participants took 12 weeks of LDV/SOF and were interviewed at enrollment and again at the end of treatment. We transcribed the interviews verbatim and coded them with NVivo software for subsequent inductive thematic analysis. Results: Nine pregnant people completed the study, leading to 18 interview transcripts. All participants identified as women. Eight women acquired HCV through injection drug use, and 1 through perinatal transmission. We identified 3 themes. (1) Treatment for HCV during pregnancy with LDV/SOF was tolerable and convenient. (2) Women described that taking investigational LDV/SOF increased their self-esteem and sense of well-being due to possible cure from HCV, and they felt that the experience of working hard to achieve cure may potentially prevent return to drug abuse in the future. (3) Women appreciated researchers and providers that gave non-judgmental care and communicated honestly, and preferred person-centered care that acknowledges women’s individual needs. Conclusions: Women stated that cure from HCV would be “life-changing,” and described antepartum treatment for HCV with LDV/SOF as tolerable and desired, when provided by non-judgmental providers. Antepartum treatment was found to be acceptable by study participants and should be further evaluated to combat the increasing HCV epidemic among young persons, including pregnant people.

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Schwarz, S., B. Hartmann, J. Sauer, R. Burgkart, S. Sudhop, D. J. Rixen i H. Clausen-Schaumann. "Contactless Vibrational Analysis of Transparent Hydrogel Structures Using Laser-Doppler Vibrometry". Experimental Mechanics 60, nr 8 (13.07.2020): 1067–78. http://dx.doi.org/10.1007/s11340-020-00626-0.

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Abstract Background Investigating the mechanical properties of biological and biocompatible hydrogels is important in tissue engineering and biofabrication. Atomic force microscopy (AFM) and compression testing are routinely used to determine mechanical properties of tissue and tissue constructs. However, these techniques are slow and require mechanical contact with the sample, rendering in situ measurements difficult. Objective We therefore aim at a fast and contactless method for determining the mechanical properties of biological hydrogels and investigate if an optical method, like Laser-Doppler vibrometry (LDV), can accomplish this task. Methods LDV is a fast contactless method for mechanical analysis. Nonetheless, LDV setups operating in the visible range of the optical spectrum are difficult to use for transparent materials, such as biological hydrogels, because LDV relies on reflected or back-scattered light from the sample. We therefore use a near-infrared (NIR) scanning LDV to determine the vibration spectra of cylindrical gelatin discs of different gelatin concentration and compare the results to AFM data and unconfined compression testing. Results We show that the gelatin test structures can be analyzed, using a NIR LDV, and the Young’s moduli can be deduced from the resonance frequencies of the first normal (0,1) mode of these structures. As expected, the frequency of this mode increases with the square root of the Young’s modulus and the damping constant increases exponentially with gelatin concentration, which underpins the validity of our approach. Conclusions Our results demonstrate that NIR wavelengths are suitable for a fast, contactless vibrational analysis of transparent hydrogel structures.

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Wei, Jie, Karmon Vongsy, Olga Mendoza-Schrock i Chi-Him Liu. "Vehicle Engine Classification Using Spectral Tone-Pitch Vibration Indexing and Neural Network". International Journal of Monitoring and Surveillance Technologies Research 2, nr 3 (lipiec 2014): 31–49. http://dx.doi.org/10.4018/ijmstr.2014070102.

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As a non-invasive and remote sensor, the Laser Doppler Vibrometer (LDV) has found a broad spectrum of applications in various areas such as civil engineering, biomedical engineering, and even security and restoration within art museums. LDV is an ideal sensor to detect threats earlier and provide better protection to society, which is of utmost importance to military and law enforcement institutions. However, the use of LDV in situational surveillance, in particular vehicle classification, is still in its infancy due to the lack of systematic investigations on its behavioral properties. In this work, as a result of the pilot project initiated by Air Force Research Laboratory, the innate features of LDV data from many vehicles are examined, beginning with an investigation of feature differences compared to human speech signals. A spectral tone-pitch vibration indexing scheme is developed to capture the engine's periodic vibrations and the associated fundamental frequencies over the vehicles' surface. A two-layer feed-forward neural network with 20 intermediate neurons is employed to classify vehicles' engines based on their spectral tone-pitch indices. The classification results using the proposed approach over the complete LDV dataset collected by the project are exceedingly encouraging; consistently higher than 96% accuracies are attained for all four types of engines collected from this project.

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Su, Dan, Thao Le-Thi-Phuong i Jean-Paul Coutelier. "Modulation of lipopolysaccharide receptor expression by lactate dehydrogenase-elevating virus". Journal of General Virology 93, nr 1 (1.01.2012): 106–12. http://dx.doi.org/10.1099/vir.0.037218-0.

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Lactate dehydrogenase-elevating virus (LDV) exacerbates mouse susceptibility to endotoxin shock through enhanced tumour necrosis factor (TNF) production by macrophages exposed to lipopolysaccharide (LPS). However, the in vivo enhancement of TNF production in response to LPS induced by the virus largely exceeds that found in vitro with cells derived from infected animals. Infection was followed by a moderate increase of Toll-like receptor (TLR)-4/MD2, but not of membrane CD14 expression on peritoneal macrophages. Peritoneal macrophages from LDV-infected mice unresponsive to type I interferons (IFNs) did not show enhanced expression of TLR-4/MD2 nor of CD14, and did not produce more TNF in response to LPS than cells from infected normal counterparts, although the in vivo response of these animals to LPS was strongly enhanced. In contrast, the virus triggered a sharp increase of soluble CD14 and of LPS-binding protein serum levels in normal mice. However, production of these LPS soluble receptors was similar in LDV-infected type I IFN-receptor deficient mice and in their normal counterparts. Moreover, serum of LDV-infected mice that contained these soluble receptors had little effect if any on cell response to LPS. These results suggest that enhanced response of LDV-infected mice to LPS results mostly from mechanisms independent of LPS receptor expression.

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Gaitan, Michael, Jon Geist, Benjamin J. Reschovsky i Ako Chijioke. "Characterization of laser Doppler vibrometers using acousto-optic modulators". ACTA IMEKO 9, nr 5 (31.12.2020): 361. http://dx.doi.org/10.21014/acta_imeko.v9i5.1001.

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We report on a new approach to characterize the performance of a laser Doppler vibrometer (LDV). The method uses two acousto-optic modulators (AOMs) to frequency shift the light from an LDV by a known quantity to create a synthetic velocity shift that is traceable to a frequency reference. Results are presented for discrete velocity shifts and for sinusoidal velocity shifts that would be equivalent to what would be observed in an ideal accelerometer vibration calibration. The method also enables the user to sweep the synthetic vibration excitation frequency to characterize the bandwidth of an LDV together with its associated electronics.

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Smedby, O¨, L. Fuchs i N. Tillmark. "Separated Flow Demonstrated by Digitized Cineangiography Compared With LDV". Journal of Biomechanical Engineering 113, nr 3 (1.08.1991): 336–41. http://dx.doi.org/10.1115/1.2894892.

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In order to demonstrate separated flow in vivo, a method for the computerized analysis of cineangiographies has been developed, tested in vitro, and compared with LDV. A pulsatile flow was created in a glass model bifurcation, and velocity profiles were obtained with LDV at several phase angles. The flow was cinefilmed during contrast injection and the images were digitized. The computer then transformed the image sequence into parametric images representing arrival times of the contrast. The separation regions demonstrated with LDV were identified as areas with delayed contrast arrival. A preliminary analysis of a cineangiography in vivo is also included.

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Legrain, Sarah, Dan Su, Mélanie Gaignage, Cor Breukel, Jill Claassens, Conny Brouwers, Margot M. Linssen, Shozo Izui, J. Sjef Verbeek i Jean-Paul Coutelier. "Involvement of Virus-Induced Interferon Production in IgG Autoantibody-Mediated Anemia". International Journal of Molecular Sciences 22, nr 16 (21.08.2021): 9027. http://dx.doi.org/10.3390/ijms22169027.

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Infection with viruses, such as the lactate dehydrogenase-elevating virus (LDV), is known to trigger the onset of autoimmune anemia through the enhancement of the phagocytosis of autoantibody-opsonized erythrocytes by activated macrophages. Type I interferon receptor-deficient mice show enhanced anemia, which suggests a protective effect of these cytokines, partly through the control of type II interferon production. The development of anemia requires the expression of Fcγ receptors (FcγR) I, III, and IV. Whereas LDV infection decreases FcγR III expression, it enhances FcγR I and IV expression in wild-type animals. The LDV-associated increase in the expression of FcγR I and IV is largely reduced in type I interferon receptor-deficient mice, through both type II interferon-dependent and -independent mechanisms. Thus, the regulation of the expression of FcγR I and IV, but not III, by interferons may partly explain the exacerbating effect of LDV infection on anemia that results from the enhanced phagocytosis of IgG autoantibody-opsonized erythrocytes.

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Feng, Jianjun, F. K. Benra i H. J. Dohmen. "Comparison of Periodic Flow Fields in a Radial Pump among CFD, PIV, and LDV Results". International Journal of Rotating Machinery 2009 (2009): 1–10. http://dx.doi.org/10.1155/2009/410838.

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The interaction between the impeller and the diffuser is considered to have a strong influence on the unsteady flow in radial pumps. In this paper, the unsteady flow in a low specific speed radial diffuser pump has been simulated by the CFD code CFX-10. Both Particle Image Velocimetry (PIV) and Laser Doppler Velocimetry (LDV) measurements have been conducted to validate the CFD results. Both the phase-averaged velocity fields and the turbulence fields obtained from different methods are presented and compared, in order to enhance the understanding of the unsteady flow caused by the relative motion between the rotating impeller and the stationary diffuser. The comparison of the results shows that PIV and LDV give nearly the same phase-averaged velocity fields, but LDV predicts the turbulence much clearer and better than PIV. CFD underestimates the turbulence level in the whole region compared with PIV and LDV but gives the same trend.

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Ivanchenko, Oleksandr, Ergin Esirgemez i Semih Ölçmen. "A miniature three-component LDV probe". Measurement Science and Technology 18, nr 7 (21.05.2007): 2014–20. http://dx.doi.org/10.1088/0957-0233/18/7/030.

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IKEDA, Yuji, Noboru KURIHARA i Tsuyoshi NAKAJIMA. "Burst Digital Correlator for LDV Signal Processing. 3rd Report. Burst Detection of LDV by Correlation Method." Transactions of the Japan Society of Mechanical Engineers Series B 58, nr 548 (1992): 1192–99. http://dx.doi.org/10.1299/kikaib.58.1192.

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Oyama, B. S., M. F. Andrade, P. Herckes, U. Dusek, T. Röckmann i R. Holzinger. "Vehicular emissions of organic particulate matter in Sao Paulo, Brazil". Atmospheric Chemistry and Physics Discussions 15, nr 23 (1.12.2015): 33755–88. http://dx.doi.org/10.5194/acpd-15-33755-2015.

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Abstract. Vehicular emissions have a strong impact on air pollution in big cities. Many factors affect these emissions: type of vehicle, type of fuel, cruising velocity, and brake use. This study focused on emissions of organic compounds by Light (LDV) and Heavy (HDV) duty vehicle exhaust. The study was performed in the city of Sao Paulo, Brazil, where vehicles run on different fuels: gasoline with 25 % ethanol (called gasohol), hydrated ethanol, and diesel (with 5 % of biodiesel). The vehicular emissions are an important source of pollutants and the principal contribution to fine particulate matter (smaller than 2.5 μm, PM2.5) in Sao Paulo. The experiments were performed in two tunnels: Janio Quadros (TJQ) where 99 % of the vehicles are LDV, and Rodoanel Mario Covas (TRA) where up to 30 % of the fleet was HDV. The PM2.5 samples were collected on quartz filters in May and July 2011 at TJQ and TRA, respectively, using two samplers operating in parallel. The samples were analyzed by Thermal-Desorption Proton-Transfer-Reaction Mass-Spectrometry (TD-PTR-MS), and by Thermal-Optical Transmittance (TOT). The organic aerosol (OA) desorbed at TD-PTR-MS represented around 30 % of the OA estimated by the TOT method, mainly due to the different desorption temperatures, with a maximum of 870 and 350 °C for TOT and TD-PTR-MS, respectively. Average emission factors (EF) organic aerosol (OA) and organic carbon (OC) were calculated for HDV and LDV fleet. We found that HDV emitted more OA and OC than LDV, and that OC emissions represented 36 and 43 % of total PM2.5 emissions from LDV and HDV, respectively. More than 700 ions were identified by TD-PTR-MS and the EF profiles obtained from HDV and LDV exhibited distinct features. Nitrogen-containing compounds measured in the desorbed material up to 350 °C contributed around 20 % to the EF values for both types of vehicles, possibly associated with incomplete fuel burning. Additionally, 70 % of the organic compounds measured from the aerosol filters with TD-PTR-MS were oxygenated for LDV and HDV, suggesting that the oxygenation occurs during fuel combustion and that the oxygen content of the fuel itself contributes. The thermal desorption analysis showed that HDV emitted compounds with higher volatility, mainly oxygenated (with up to 2 oxygen atoms) and longer chain hydrocarbons than LDV.

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Ciancio, Alessia. "Ledipasvir/sofosbuvir: the fixed dose combination in the new era of treatment for HCV". Reviews in Health Care 6, nr 3 (30.07.2015): 87–98. http://dx.doi.org/10.7175/rhc.v6i3.1178.

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Interferon-based treatment is not suitable for many patients with hepatitis C virus (HCV) infection because of contraindications, other reasons for ineligibility and side-effects. The fixed dosed combination ledipasvir/sofosbuvir (LDV / SOF) is the first approved regimen that doesn’t require administration with interferon or ribavirin. LDV / SOF is also the first single-pill approved for the treatment of chronic HCV genotype 1 in both treatment-naïve and treatment-experienced patients. The results of the phase III studies demonstrate the combination has been very well tolerated and SVR rates consistently above 90%. Objective of this review is to present clinical evidence of efficacy and safety of the combination LDV / SOF in different subgroups of patients with HCV.

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Eroglu, Hasan, i Widen Tabakoff. "LDV Measurements and Investigation of Flow Field Through Radial Turbine Guide Vanes". Journal of Fluids Engineering 113, nr 4 (1.12.1991): 660–67. http://dx.doi.org/10.1115/1.2926531.

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The results of LDV measurements and investigation of the detailed flow field in a radial inflow turbine nozzle are presented. The flow velocities were measured at upstream, inside and downstream of the nozzle blades for two different mass flow rates, using a three-component LDV system. Results are presented as contour plots of mean velocities, flow angles, and turbulence intensities. The flow field inside the nozzle blade passages was found to be influenced by the upstream scroll geometry. The flow turbulence increased in the downstream flow direction. The LDV mean flow results on the blade-to-blade midspan plane which is parallel to the end walls were also compared with an inviscid, “panel method” solution.

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Castellini, Paolo, Milena Martarelli i Enrico Primo Tomasini. "Laser Doppler Vibrometry for Structural Dynamic Characterization of Rotating Machinery". Applied Mechanics and Materials 415 (wrzesień 2013): 538–43. http://dx.doi.org/10.4028/www.scientific.net/amm.415.538.

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Laser Doppler Vibrometry (LDV) is a well established technique able to accurately measure vibration velocity of any kind of structure in remote, i.e. non-intrusive way, this allowing to overcome the problem of mass loading, typical of contact sensors as accelerometers and strain-gauges, which has strong influence in case of lightweight structures. Moreover, the possibility of driving automatically the laser beam, by means of moving mirrors controlled with galvanometer servo-actuators, permits to perform scanning measurements at different locations with high spatial resolution and reduced testing time and easily measure the operational deflection shapes (ODS) of the scanned surface. The exploitation of the moving mirrors has allowed to drive the laser beam in a continuous way making it to scan continuously over the structure surface and cover it completely. This way of operation, named Continuous Scanning LDV, permits to perform full-field measurements, the LDV output carrying simultaneously the time-and spatial-dependent information related to the structural vibration. A complementary strategy making use of the LDV coupled with moving mirrors is the so called Tracking LDV, where the laser beam is driven to follow a moving object whose trajectory must be known a priori or measured during operation (e.g. via an encoder in the case of rotating structures). In this paper some applications of the Tracking Laser Doppler Vibrometry (TLDV) and Continuous Scanning Laser Doppler Vibrometry (CSLDV) will be described they concerning, specifically modal and vibrational analysis of rotating structures.

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Daxer, Barbara, Haifa Mahmood i Albert Daxer. "MyoRing Treatment for Keratoconus: DIOPTEX PocketMaker vs Ziemer LDV for Corneal Pocket Creation". International Journal of Keratoconus and Ectatic Corneal Diseases 1, nr 3 (2012): 151–52. http://dx.doi.org/10.5005/jp-journals-10025-1029.

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ABSTRACT Purpose To compare the results of MyoRing implantation for keratoconus using two different techniques for corneal pocket creation. Materials and methods Seven eyes suffering from keratoconus were treated using Ziemer LDV for corneal pocket creation and seven eyes suffering from keratoconus were treated using DIOPTEX PocketMaker for corneal pocket creation. Results Both groups did not show any statistically significant difference, neither in the severity of the disease nor in the results. Conclusion Ziemer LDV and DIOPTEX PocketMaker give equal results for MyoRing implantation for keratoconus. How to cite this article Daxer B, Mahmood H, Daxer A. MyoRing Treatment for Keratoconus: DIOPTEX PocketMaker vs Ziemer LDV for Corneal Pocket Creation. Int J Kerat Ect Cor Dis 2012;1(3):151-152.

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Shang, Jianhua, Yan He, Qi Wang, Yilun Li i Lihong Ren. "Development of a High-Resolution All-Fiber Homodyne Laser Doppler Vibrometer". Sensors 20, nr 20 (14.10.2020): 5801. http://dx.doi.org/10.3390/s20205801.

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Based on the homodyne detection, a compact and cost-effective all-fiber laser Doppler vibrometer (LDV) with high resolution is presented. For the signal processing, the discrimination algorithm combined with the nonorthogonal correction is applied. The algorithm corrects the quadrature imbalance and other nonlinearity. In the calibration experiment, with the glass pasted on a piezoceramic transducer (PZT), the velocity resolution of 62 nm/s at 4 kHz and displacement resolution of 2.468 pm are achieved. For the LDV-based acousto-optic communication, the minimum detectable sound pressure level (SPL) reached 0.12 Pa under the hydrostatic air-water surface. The results demonstrate that the designed homodyne LDV has a low system background noise and can offer high precision in the vibration measurement.

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Fagan, J. R., i S. Fleeter. "Impeller Flow Field Measurement and Analysis". Journal of Turbomachinery 113, nr 4 (1.10.1991): 670–79. http://dx.doi.org/10.1115/1.2929133.

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A series of experiments are performed to investigate and quantify the three-dimensional mean flow field in centrifugal compressor flow passages and to evaluate contemporary internal flow models. The experiments include the acquisition and analysis of LDV data in the impeller passages of a low-speed moderate-scale research mixed-flow centrifugal compressor operating at its design point. Predictions from a viscous internal flow model are then correlated with these data. The LDV data show the traditional jet-wake structure observed in many centrifugal compressors, with the wake observed along the shroud 70 percent of the length from the pressure to suction surface. The viscous model predicts the major flow phenomena. However, the correlations of the viscous predictions with the LDV data were poor.

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Elsayed, Amr, Ehab M Abdelraheem, Hatem Hassan, Abbas Abbas i Alshymaa Hassnine. "Efficacy of antiviral therapy in patients with post-hepatitis C liver cirrhosis: is hyperuricaemia a potential adverse effect?" BMJ Open Gastroenterology 7, nr 1 (grudzień 2020): e000533. http://dx.doi.org/10.1136/bmjgast-2020-000533.

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Hepatitis C virus (HCV) related liver cirrhosis is considered a major health problem; sofosbuvir (SOF)/ledipasvir (LDV) and SOF/daclatsvir (DACLA) are very promising direct antiviral agents (DAAS) especially in treating HCV genotype 4 which is the main genotype in Egypt. Uric acid elevation was reported in many systemic diseases and might be elevated during direct antiviral therapy. The aim is to evaluate efficacy and safety of SOF/LDV and SOF/DACLA plus ribavirin in treating HCV related child A liver cirrhosis and assess hyperuricaemia as a potential adverse effect to this regimen.MethodsThis prospective observatinal study included 128 HCV naive child A cirrhotic patients divided into two groups (77 patients were treated with SOF 400 mg, DACLA 60 mg and ribavirin 600 mg and 51 patients were treated with SOF 400 mg, LDV 90 mg and ribavirin 600 mg) for 12 weeks, during the treatment complete blood count, creatinine, bilirubin, alanine transaminase, aspartate transaminase and serum uric acid were monitored, HCV RNA quantitative PCR at 12 weeks after the end of treatment was done.ResultsResponse to treatment in SOF/LDV (sof/led) group is about (98%), response to treatment in SOF/DACLA (sof/dacla) group is about (96%). Hyperuricaemia was noticed in 17.6% of patients received sof/led and in 15.5% of those received sof/dacla.ConclusionSOF+LDV and SOF+DACLA plus ribavirin regimens are highly effective in treating chronic HCV patients with compensated liver cirrhosis. Hyperuricaemia is considered a potential adverse effect to DAAS containing ribavirin and may lead to serious side effects such as renal impairment.

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Doga, A. V., I. A. Mushkova, A. D. Semenov, A. N. Karimova, E. V. Kechin i I. N. Shormaz. "Morphometric Parameters of the Corneal Flap after FemtoLASIK Using Various Femtosecond Laser". Ophthalmology in Russia 15, nr 2 (5.07.2018): 115–23. http://dx.doi.org/10.18008/1816-5095-2018-2-115-123.

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Purpose:to make a comparison of the corneal flap parameters after the FemtoLASIK procedure using femtolaser systems Femto Visum (Russia) and Femto LDV Z6 (Switzerland).Patients and methods.The study was carried out in 192 eyes from 192 patients with mild and moderate myopia who had undergone FemtoLASIK prodecure. Group 1 (Femto Visum) included 98 eyes (n = 98) on which flap were formed using femtolaser Femto Visum (“Optosystems”, Russia), group 2 (Femto LDV Z6) included 94 eyes (n = 94) and Femto LDV Z6 was used (“Ziemer Ophthalmic Systems AG”, Switzerland). The Femto Visum and Femto LDV Z6 groups were comparable in terms of pre-operative data (age, sex, corneal curvature, central corneal thickness, sphere, cylinder, spherical equivalent) (p > 0.05). The intended flap thickness was 100 μm and diameter was 9.0 mm in both groups. One month after surgery the achieved flap thickness in the horizontal and vertical meridians (14 measurement points) and the flap diameter in the horizontal meridian were measured using Visante OCT (Carl Zeiss, Germany), also we determined the shape of the flap and the mean deviation of the values from morphometric parameters of the corneal flap relative to the intended values.Results.In group 1 (Femto Visum), the total average thickness of the flap was 98.89 ± 3.96 μm with the mean deviation 2.91 ± 2.91 μm, the mean flap diameter was 8.96 ± 0.13 mm with the mean deviation 0.11 ± 0.07 mm, in group 2 (Femto LDV Z6) the same parameters were 99.11 ± 3.89 μm, 2.99 ± 2.64 μm and 8.91 ± 0.14 mm, 0.13 ± 0.10 mm, respectively. The configuration of the corneal flap was uniform in both groups. For all studied parameters it was no any statistically significant differences between studied groups (p > 0.05, Student’s t-test).Conclusions.The Femto Visum and Femto LDV Z6 femtolaser systems allow to shape the uniform and highly predictable corneal flap morphometric parameters, similar measurements were obtained from both systems.

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Lancaster, John, Michèle Lucarotti, Alison Mitchell i David Leaper. "Laser Doppler Flowmetric and Waveform Changes in Patients with Venous Reflux". Phlebology: The Journal of Venous Disease 3, nr 1 (marzec 1988): 69–72. http://dx.doi.org/10.1177/026835558800300110.

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Laser Doppler velocimetry (LDV) is useful in measurement of relative tissue blood flow. We have found a change in both the variability of the LDV waveform and its absolute level, when measured in the supine and dependent lower limb, in patients with venous reflux. This change correlated well with simultaneous photo-plethysmographic (PPG) assessment of venous reflux and was more pronounced in patients with leg ulcers.

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