The first detection of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO) in 2015 launched the era of gravitational-wave astronomy. The quest for gravitational-wave ...signals from objects that are fainter or farther away impels technological advances to realize ever more sensitive detectors. Since 2019, one advanced technique, the injection of squeezed states of light, is being used to improve the shot-noise limit to the sensitivity of the Advanced LIGO detectors, at frequencies above ∼50 Hz. Below this frequency, quantum backaction, in the form of radiation pressure induced motion of the mirrors, degrades the sensitivity. To simultaneously reduce shot noise at high frequencies and quantum radiation pressure noise at low frequencies requires a quantum noise filter cavity with low optical losses to rotate the squeezed quadrature as a function of frequency. We report on the observation of frequency-dependent squeezed quadrature rotation with rotation frequency of 30 Hz, using a 16-m-long filter cavity. A novel control scheme is developed for this frequency-dependent squeezed vacuum source, and the results presented here demonstrate that a low-loss filter cavity can achieve the squeezed quadrature rotation necessary for the next planned upgrade to Advanced LIGO, known as "A+."
This study compared the relative cellular uptake of 80 nm silver nanoparticles (AgNP) with four different coatings including: branched polyethyleneimine (bPEI), citrate (CIT), polyvinylpyrrolidone ...(PVP), and polyethylene glycol (PEG). A gold nanoparticle PVP was also compared to the silver nanoparticles. Biophysical parameters of cellular uptake and effects included flow cytometry side scatter (SSC) intensity, nuclear light scatter, cell cycle distributions, surface plasmonic resonance (SPR), fluorescence microscopy of mitochondrial gross structure, and darkfield hyperspectral imaging. The AgNP-bPEI were positively charged and entered cells at a higher rate than the negatively or neutrally charged particles. The AgNP-bPEI were toxic to the cells at lower doses than the other coatings which resulted in mitochondria being transformed from a normal string-like appearance to small round beaded structures. Hyperspectral imaging showed that AgNP-bPEI and AgNP-CIT agglomerated in the cells and on the slides, which was evident by longer spectral wavelengths of scattered light compared to AgNP-PEG and AgNP-PVP particles. In unfixed cells, AgNP-CIT and AgNP-bPEI had higher SPR than either AgNP-PEG or AgNP-PVP particles, presumably due to greater intracellular agglomeration. After 24 hr. incubation with AgNP-bPEI, there was a dose-dependent decrease in the G1 phase and an increase in the G2/M and S phases of the cell cycle suggestive of cell cycle inhibition. The nuclei of all the AgNP treated cells showed a dose-dependent increase in nanoparticles following non-ionic detergent treatment in which the nuclei retained extra-nuclear AgNP, suggesting that nanoparticles were attached to the nuclei or cytoplasm and not removed by detergent lysis. In summary, positively charged AgNP-bPEI increased particle cellular uptake. Particles agglomerated in the peri-nuclear region, increased mitochondrial toxicity, disturbed the cell cycle, and caused abnormal adherence of extranuclear material to the nucleus after detergent lysis of cells. These results illustrate the importance of nanoparticle surface coatings and charge in determining potentially toxic cellular interactions.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The Hippo pathway regulates organ size by inhibiting cell proliferation and promoting cell apoptosis upon its activation. The Yes Associated Protein 1 (YAP1) is a nuclear effector of the Hippo ...pathway that promotes cell growth as a transcription co-activator. In human cancer, the YAP1 gene was reported as amplified and over-expressed in several tumor types.
Immunohistochemical staining of YAP1 protein was used to assess the expression of YAP1 in pancreatic tumor tissues. siRNA oligonucleotides were used to knockdown the expression of YAP1 and their effects on pancreatic cancer cells were investigated using cell proliferation, apoptosis, and anchorage-independent growth assays. The Wilcoxon signed-rank, Pearson correlation coefficient, Kendall's Tau, Spearman's Rho, and an independent two-sample t (two-tailed) test were used to determine the statistical significance of the data.
Immunohistochemistry studies in pancreatic tumor tissues revealed YAP1 staining intensities were moderate to strong in the nucleus and cytoplasm of the tumor cells, whereas the adjacent normal epithelial showed negative to weak staining. In cultured cells, YAP1 expression and localization was modulated by cell density. YAP1 total protein expression increased in the nuclear fractions in BxPC-3 and PANC-1, while it declined in HPDE6 as cell density increased. Additionally, treatment of pancreatic cancer cell lines, BxPC-3 and PANC-1, with YAP1-targeting siRNA oligonucleotides significantly reduced their proliferation in vitro. Furthermore, treatment with YAP1 siRNA oligonucleotides diminished the anchorage-independent growth on soft agar of pancreatic cancer cells, suggesting a role of YAP1 in pancreatic cancer tumorigenesis.
YAP1 is overexpressed in pancreatic cancer tissues and potentially plays an important role in the clonogenicity and growth of pancreatic cancer cells.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
During studies on the absorption and interactions between silver nanoparticles and mammalian cells grown in vitro it was observed that large extracellular rings of silver nanoparticles were deposited ...on the microscope slide, many located near post-mitotic cells. Silver nanoparticles (AgNP, 80nm), coated with citrate, were incubated at concentrations of 0.3 to 30 μg/ml with a human-derived culture of retinal pigment epithelial cells (ARPE-19) and observed using darkfield and fluorescent microscopy, 24 h after treatment. Approximately cell-sized extracellular rings of deposited AgNP were observed on the slides among a field of dispersed individual AgNP. The mean diameter of 45 nanoparticles circles was 62.5 +/-12 microns. Ring structures were frequently observed near what appeared to be post-mitotic daughter cells, giving rise to the possibility that cell membrane fragments were deposited on the slide during mitosis, and those fragments selectively attracted and retained silver nanoparticles from suspension in the cell culture medium. These circular structures were observable for the following technical reasons: 1) darkfield microscope could observe single nanoparticles below 100 nm in size, 2) a large concentration (108 and 109) of nanoparticles was used in these experiments 3) negatively charged nanoparticles were attracted to adhesion membrane proteins remaining on the slide from mitosis. The observation of silver nanoparticles attracted to apparent remnants of cellular mitosis could be a useful tool for the study of normal and abnormal mitosis.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Ensuring equitable and fair organ allocation is a central charge of the United Network for Organ Sharing (UNOS) as the Organ Procurement and Transplantation Network (OPTN) through its contract with ...the Department of Health and Human Services (DHHS). The OPTN/UNOS Board initiated a reassessment of the current allocation system. This paper describes the efforts of the OPTN/UNOS Heart Subcommittee, acting on behalf of the OPTN/UNOS Thoracic Organ Transplantation Committee, to modify the current allocation system. The Subcommittee assessed the limitations of the current three‐tiered system, outcomes of patients with status exceptions, emerging ventricular assist device (VAD) population, options for improved geographic sharing and status of potentially disenfranchised groups. They analyzed waiting list and posttransplant mortality rates of a contemporary cohort of patient groups at risk, in collaboration with the Scientific Registry of Transplant Recipients to develop a proposed multi‐tiered allocation scheme. This proposal provides a framework for simulation modeling to project whether candidates would have better waitlist survival in the revised allocation system, and whether posttransplant survival would remain stable. The tiers are subject to change, based on further analysis by the Heart Subcommittee and will lead to the development of a more effective and equitable heart allocation system.
The Thoracic Committee of the United Network for Organ Sharing is proposing a revised, multi‐tier heart allocation scheme in the United States that is designed to improve priority stratification based primarily upon contemporary waitlist mortality risk. Also see editorial by Barr and Taylor (page 7) and meeting report by Kobashigawa et al (page 55).
Summary
Background
Factor XI (FXI) deficiency is a rare autosomal recessive disorder. Many patients with even very low FXI levels (< 20 IU dL−1) are asymptomatic or exhibit only mild bleeding, ...whereas others experience severe bleeding, usually following trauma. Neither FXI antigen nor activity predicts the risk of bleeding in FXI‐deficient patients.
Objectives
(i) Characterize the formation, structure and stability of plasma clots from patients with severe FXI deficiency and (ii) determine whether these assays can distinguish asymptomatic patients (‘non‐bleeders’) from those with a history of bleeding (‘bleeders’).
Methods
Platelet‐poor plasmas were prepared from 16 severe FXI‐deficient patients who were divided into bleeders or non‐bleeders, based on bleeding associated with at least two tooth extractions without prophylaxis. Clot formation was triggered by recalcification and addition of tissue factor and phospholipids in the absence or presence of tissue plasminogen activator and/or thrombomodulin. Clot formation and fibrinolysis were measured by turbidity and fibrin network structure by laser scanning confocal microscopy.
Results
Non‐bleeders and bleeders had similarly low FXI levels, normal prothrombin times, normal levels of fibrinogen, factor VIII, von Willebrand factor and factor XIII, and normal platelet number and function. Compared with non‐bleeders, bleeders exhibited lower fibrin network density and lower clot stability in the presence of tissue plasminogen activator. In the presence of thrombomodulin, seven of eight bleeders failed to form a clot, whereas only three of eight non‐bleeders did not clot.
Conclusions
Plasma clot structure and stability assays distinguished non‐bleeders from bleeders. These assays may reveal hemostatic mechanisms in FXI‐deficient patients and have clinical utility for assessing the risk of bleeding.
Résumé
Une étude du sentiment de guérison à distance d’un cancer traité avant l’âge de 15 ans a été conduite, au cours d’entretiens semi-directifs menés par la psychologue, chez 25 jeunes gens de 18 ...à 31 ans médicalement guéris, recrutés à l’occasion d’une consultation de suivi avec le même oncopédiatre référent 8 à 20 ans après le diagnostic. Les traces ineffaçables du traumatisme du cancer, dont le travail d’élaboration reste le plus souvent incomplet, sont soulignées de façon récurrente par les anciens patients: la soudaineté de l’entrée dans la maladie et l’ébranlement existentiel qu’elle a déterminés (séparation d’avec le monde familier d’avant et apprentissage de la précarité). La gravité ressentie de la situation, le plus souvent liée aux sensations douloureuses provoquées par la tumeur et les agressions diagnostiques et thérapeutiques, est reflétée dans les yeux et l’attitude des proches. La solitude omniprésente à l’hôpital, au sein de sa fratrie, comme parmi les pairs. Si la présence réconfortante des parents et l’information dédramatisante du médecin sont dans le souvenir des patients leurs deux planches de salut, la mort refoulée affleure dans presque tous les entretiens. Ceux-ci suggèrent chez les anciens patients la coexistence prolongée de trois sentiments de guérison: envisagée grâce à la parole médicale comme possible, vécue dans la crainte de rechutes et de séquelles comme incertaine, la guérison paraît surtout durablement inachevée, caractérisée notamment par la difficulté de sortir du statut d’enfant précaire et de formuler un projet parental.
The most advantageous combination of immunosuppressive agents for cardiac transplant recipients has not yet been established. Between November 2001 and June 2003, 343 de novo cardiac transplant ...recipients were randomized to receive steroids and either tacrolimus (TAC) + sirolimus (SRL), TAC + mycophenolate mofetil (MMF) or cyclosporine (CYA) + MMF. Antilymphocyte induction therapy was allowed for up to 5 days. The primary endpoint of ≥3A rejection or hemodynamic compromise rejection requiring treatment showed no significant difference at 6 months (TAC/MMF 22.4%, TAC/SRL 24.3%, CYA/MMF 31.6%, p = 0.271) and 1 year (p = 0.056), but it was significantly lower in the TAC/MMF group when compared only to the CYA/MMF group at 1 year (23.4% vs. 36.8%; p = 0.029). Differences in the incidence of any treated rejection were significant (TAC/SRL = 35%, TAC/MMF = 42%, CYA/MMF = 59%; p < 0.001), as were median levels of serum creatinine (TAC/SRL = 1.5 mg/dL, TAC/MMF = 1.3 mg/dL, CYA/MMF = 1.5 mg/dL; p = 0.032) and triglycerides (TAC/SRL = 162 mg/dL, TAC/MMF = 126 mg/dL, CYA/MMF = 154 mg/dL; p = 0.028). The TAC/SRL group encountered fewer viral infections but more fungal infections and impaired wound healing. These secondary endpoints suggest that the TAC/MMF combination appears to offer more advantages than TAC/SRL or CYA/MMF in cardiac transplant patients, including fewer ≥3A rejections or hemodynamic compromise rejections and an improved side‐effect profile.
Evaluation of the potential hazard of man‐made nanomaterials has been hampered by a limited ability to observe and measure nanoparticles in cells. In this study, different concentrations of TiO2 ...nanoparticles were suspended in cell culture medium. The suspension was then sonicated and characterized by dynamic light scattering and microscopy. Cultured human‐derived retinal pigment epithelial cells (ARPE‐19) were incubated with TiO2 nanoparticles at 0, 0.1, 0.3, 1, 3, 10, and 30 μg/ml for 24 hours. Cellular reactions to nanoparticles were evaluated using flow cytometry and dark field microscopy. A FACSCalibur™ flow cytometer was used to measure changes in light scatter after nanoparticle incubation. Both the side scatter and forward scatter changed substantially in response to the TiO2. From 0.1 to 30 μg/ml TiO2, the side scatter increased sequentially while the forward scatter decreased, presumably due to substantial light reflection by the TiO2 particles. Based on the parameters of morphology and the calcein‐AM/propidium iodide viability assay, TiO2 concentrations below 30 μg/ml TiO2 caused minimal cytotoxicity. Microscopic analysis was done on the same cells using an E‐800 Nikon microscope containing a xenon light source and special dark field objectives. At the lowest concentrations of TiO2 (0.1–0.3 μg/ml), the flow cytometer could detect as few as 5–10 nanoparticles per cell due to intense light scattering by TiO2. Rings of concentrated nanoparticles were observed around the nuclei in the vicinity of the endoplasmic reticulum at higher concentrations. These data suggest that the uptake of nanoparticles within cells can be monitored with flow cytometry and confirmed by dark field microscopy. This approach may help fulfill a critical need for the scientific community to assess the relationship between nanoparticle dose and cellular toxicity Such experiments could potentially be performed more quickly and easily using the flow cytometer to measure both nanoparticle uptake and cellular health. Published 2010 Wiley‐Liss, Inc.
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