ABSTRACT
In recent years, millisecond-duration radio signals originating in distant galaxies appear to have been discovered in the so-called fast radio bursts. These signals are dispersed according to a precise physical law and this dispersion is a key observable quantity, which, in tandem with a redshift measurement, can be used for fundamental physical investigations. Every fast radio burst has a dispersion measurement, but none before now have had a redshift measurement, because of the difficulty in pinpointing their celestial coordinates. Here we report the discovery of a fast radio burst and the identification of a fading radio transient lasting ~6 days after the event, which we use to identify the host galaxy; we measure the galaxy's redshift to be z = 0.492 ± 0.008. The dispersion measure and redshift, in combination, provide a direct measurement of the cosmic density of ionized baryons in the intergalactic medium of ΩIGM = 4.9 ± 1.3 per cent, in agreement with the expectation from the Wilkinson Microwave Anisotropy Probe, and including all of the so-called 'missing baryons'. The ~6-day radio transient is largely consistent with the radio afterglow of a short γ-ray burst, and its existence and timescale do not support progenitor models such as giant pulses from pulsars, and supernovae. This contrasts with the interpretation of another recently discovered fast radio burst, suggesting that there are at least two classes of bursts.
ABSTRACT
This study presents a method of measuring the activity of a specific radionuclide 234mPa in samples placed in bulk transport containers under changing background conditions. The method makes it possible to measure specific activity of 234 mPa in objects without the need for sampling. The change in the effective sample volume limited by the surfaces of the containers is considered depending on the density of the measured material and the energy of gamma radiation of the radionuclide. The high sensitivity of scintillation detector, supplemented by adequate Monte Carlo simulation, allows spectrum measurements to be taken in a short time (less than an hour) with subsequent determination of specific activity. A comparison of measurement results and calculation of 234mPa activity in samples with different densities and compositions using the proposed algorithm, and those obtained by an HPGe spectrometer, demonstrated the high efficiency of the proposed solution.
ABSTRACT
Cilia-driven nodal flow is important in the determination of left-right asymmetry in the body. Several theoretical and computational models have been proposed to explain the mechanics of ciliary motion, although the full mechanism remains unknown. Here, we developed a three-dimensional nodal cilia axoneme model using a finite element-boundary element coupling method, and investigated the mechanics of nodal ciliary motion. We found that the rotational orbit was strongly dependent on the dynein activation frequency. We also investigated flow field generated by the ciliary rotation, and the flow strength decayed as r-3 at the far field from the cilium. Our numerical results also suggest that experimentally observed tilt angle θ=2π/9 is sufficiently large to make a leftward flow. These findings are helpful in better understanding ciliary motion and nodal flow.
Subject(s)
Axoneme/ultrastructure , Cilia/ultrastructure , Algorithms , Cilia/physiology , Computer Simulation , Dyneins/chemistry , Finite Element Analysis , Models, Molecular , Motion , Protein Structure, QuaternaryABSTRACT
We demonstrate that the sheath created adjacent to the surface of a negatively biased electrode that interfaces an insulator acts as a lens that focuses the positive ions to distinct regions on the surface. Thus, the positive ion flux is discrete, leading to the formation of a passive surface, of no ion impact, near the edge and an active surface at the center. Trajectories of positive ions within the sheath are obtained by solving in three dimensions the Poisson equation for electrodes of different geometry. Simulations are confirmed by developing the ion flux profile on the electrode surface as the sputtering pattern produced by ion impact. Measurements are performed in a dc plasma produced in Ar gas.
ABSTRACT
A self-consistent fluid theory of complex electronegative colloidal plasmas in parallel-plate low-pressure discharge is presented. The self-organized low-pressure diffusion equilibrium is maintained through sources and sinks of electrons, positive and negative ions, in plasmas containing dust grains. It is shown that the colloidal dust grain subsystem strongly affects the stationary state of the discharge by dynamically modifying the electron temperature and particle creation and loss processes. The model accounts for ionization, ambipolar diffusion, electron and ion collection by the dusts, electron attachment, positive-ion-negative-ion recombination, and relevant elastic and inelastic collisions. The spatial profiles of electron and positive-ion-negative-ion number densities, electron temperature, and dust charge in electronegative SiH4 discharges are obtained for different grain size, input power, neutral gas pressure, and rates of negative-ion creation and loss.
ABSTRACT
Optic disc swelling was measured by computerized image analysis in diabetic patients. The subjects were divided into four groups. Group 1 contained 13 eyes without diabetic retinopathy, group 2, 14 eyes with a mild stage of simple diabetic retinopathy, group 3, 14 eyes with a severe stage of simple diabetic retinopathy and group 4, 14 eyes with preproliferative diabetic retinopathy. There were statistically significant differences in the optic disc swelling between group 1 and group 4, and between group 2 and group 4 (p < 0.05). The optic disc swelling increased as the stage of diabetic retinopathy progressed.
Subject(s)
Diabetic Retinopathy/pathology , Image Processing, Computer-Assisted , Optic Disk/pathology , Diabetic Retinopathy/classification , Humans , Middle AgedABSTRACT
To 13 uremic patients with secondary hyperparathyroidism, 4 micrograms of 1,25(OH)2D3 were given orally twice a week for 4 weeks. Intact PTH values fell from 488.3 +/- 84.2 to 235.2 +/- 59.6 pg/ml (Mean +/- SE, p less than 0.01), while serum total and ionized calcium elevated from 10.3 +/- 0.2 to 11.8 +/- 0.6 mg/dl (p less than 0.01), from 1.43 +/- 0.03 to 1.64 +/- 0.06 mmol/l (p less than 0.05), respectively, in 9 patients whose initial intact PTH level had been below 1000 pg/ml. The other 4 patients, of whom intact PTH level had been above 1000 pg/ml, did not show significant change in intact PTH values, though serum ionized calcium elevated slightly after this treatment. The correlation curve, determined by ionized calcium and intact PTH values in each period, was found to shift in only 2 out of 5. During the 4 weeks of high dose oral 1,25(OH)2D3 therapy, mean blood pressure elevated from 92.4 +/- 3.3 to 103.5 +/- 3.5 mmHg (p less than 0.01) in general, and 7 patients out of 13 complained of mental irritability. These data suggest that oral administration of high dose 1,25(OH)2D3 suppresses PTH secretion of uremic patients directly, however, reliability of this effect is still controversial. Indication of this therapy and adverse effects caused by rapid increase in serum calcium should be studied in more detail.
Subject(s)
Calcitriol/administration & dosage , Hyperparathyroidism, Secondary/drug therapy , Administration, Oral , Adult , Calcitriol/adverse effects , Calcitriol/pharmacology , Calcium/blood , Chronic Disease , Depression, Chemical , Female , Glomerulonephritis/complications , Humans , Hyperparathyroidism, Secondary/etiology , Hypertension/chemically induced , Male , Middle Aged , Parathyroid Hormone/metabolismABSTRACT
It has been reported that the population of regulatory T cells (T regs) is increased in tumour-infiltrating lymphocytes in cancer-bearing hosts. Recently, forkhead/winged helix transcription factor p3, Foxp3, is thought to be the most reliable marker of T regs. In the present study, we investigated the prevalence and localisation pattern of Foxp3+ cells in gastric cancer (n=80) by immunohistochemistry, in relation to the clinical outcome of gastric cancer patients. Immunohistochemical staining was performed with anti-Foxp3 mAb, and Foxp3+ cells were semiquantified. We divided all cases into two groups: Foxp3+ -high (n=40) and Foxp3+ -low (n=40) groups, by the median size of the population of Foxp3+ cells. Furthermore, in terms of the localisation pattern of accumulating Foxp3+ cells in tumours, we classified all cases into three groups: a peri-tumour group (n=30), a diffuse group (n=40), and a follicular group (n=10). As a result, although the populations of Foxp3+ cells in stage IV were significantly larger than those in stage I (P<0.05), there was no significant difference in survival between the patients with high and low population levels of Foxp3+ cells. However, survival in patients with a diffuse pattern of Foxp3+ cells was significantly poorer than in those with a peri-tumoral pattern. In conclusion, the localisation pattern, but not the population size, of Foxp3+ cells was significantly related to patient survival.
Subject(s)
Forkhead Transcription Factors/metabolism , Stomach Neoplasms/metabolism , T-Lymphocytes, Regulatory/metabolism , Adenocarcinoma, Follicular/immunology , Adenocarcinoma, Follicular/metabolism , Adenocarcinoma, Follicular/pathology , Female , Humans , Immunoenzyme Techniques/methods , Intestinal Neoplasms/immunology , Intestinal Neoplasms/metabolism , Intestinal Neoplasms/pathology , Lymphatic Metastasis , Lymphocytes, Tumor-Infiltrating/metabolism , Male , Middle Aged , Prognosis , Stomach Neoplasms/immunology , Stomach Neoplasms/pathology , Survival Rate , T-Lymphocytes, Regulatory/immunologyABSTRACT
We previously reported that oesophageal squamous cell carcinoma (SCC) had a relatively high incidence of EGFR and HER-2 overexpression. Thus, anti-HER family targeting may become a promising approach to treat oesophageal SCC. In the present study, we investigated (a) the distribution of EGFR and HER-2 expression in oesophageal SCC (n=66) detected by immunohistochemistry and (b) cetuximab- and/or trastuzumab-mediated biological activity (antiproliferative effect by the MTT assay, apoptosis-inducing activity by the annexin V/propidium iodide assay, and antibody-dependent cellular cytotoxicity (ADCC) by the (51)Cr-release assay) against oesophageal SCC cell lines with various levels of EGFR and HER-2. Twelve of the 66 patients (18%) showed both EGFR- and HER-2 expression. Out of both EGFR- and HER-2-positive cases, nine cases (75%) showed EGFR and HER-2 expression in individually distinct regions. Furthermore, the combination of cetuximab and trastuzumab could induce synergistic antiproliferative effects and additional ADCC activities against not all, but several oesophageal SCC cell lines with EGFR and HER-2 expression. The combination of cetuximab and trastuzumab may be useful in the treatment of oesophageal SCC with EGFR and HER-2 expression.
Subject(s)
Antibodies, Monoclonal/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Squamous Cell/therapy , ErbB Receptors/antagonists & inhibitors , Esophageal Neoplasms/therapy , Immunotherapy , Receptor, ErbB-2/antagonists & inhibitors , Aged , Aged, 80 and over , Antibodies, Monoclonal/pharmacology , Antibodies, Monoclonal, Humanized , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Carcinoma, Squamous Cell/genetics , Carcinoma, Squamous Cell/mortality , Cell Proliferation/drug effects , Cetuximab , ErbB Receptors/genetics , ErbB Receptors/immunology , Esophageal Neoplasms/genetics , Esophageal Neoplasms/mortality , Female , Gene Expression Regulation, Neoplastic , Humans , Male , Middle Aged , Receptor, ErbB-2/genetics , Receptor, ErbB-2/immunology , Survival Analysis , Trastuzumab , Tumor Cells, CulturedABSTRACT
A complex focusing effect of positive and negative ions caused by the sheath forming to biased electrodes that interface insulators has been found by solving in three dimensions the potential distribution and ion kinetics within the sheath. Thus, intrinsically correlated with the sheath shape, certain electrical charges are focused on the surface, forming well defined patterns named modal lines and modal spots. Their superposition to the previously reported discrete focusing leads to a total flux that represents a "fingerprint" of the entire sheath on the electrode surface. The ion flux pattern is developed experimentally on the surface of square and octagonal electrodes exposed to Ar/SF(6) and CF4 plasmas. Present results are of high potential importance for fundamental studies concerning sheath formation and charge kinetics and also in a wide range of plasma applications.
ABSTRACT
The utilisation of antitumour T cells induced by cancer vaccination with HER-2 peptides or antibodies (Herceptin) against HER-2, as immunotherapy for oesophageal cancer, is a novel and attractive approach. It is important to clarify the frequencies of HER-2 expression and gene amplification in patients with oesophageal squamous cell carcinoma (SCC) and to evaluate the relationship between HER-2 status and HLA haplotype, since the candidates for HER-2 peptide-based vaccination are restricted to a certain HLA haplotype. We determined the frequency of HER-2 expression using the HercepTest for immunohistochemistry and HER-2 gene amplification by fluorescence in situ hybridisation (FISH) assay in oesophageal SCC (n=66). HER-2-positive tumours (1+/2+/3+) analysed by a HercepTest were observed in 30.3% of all the patients and HER-2 gene amplification evaluated by FISH was observed in 11.0% of all the patients, in which all HercepTest (3+) tumours were found to have gene amplification and three of six moderately positive (2+) tumours showed gene amplification. Furthermore, HER-2-positive cells were present more diffusely and were larger within each tumour in the patients who were HercepTest 3+ than those who were HercepTest 1+. Moreover, the survival rate in HER-2-positive group was significantly worse than that in HER-2-negative group. Also, the survival rate in the patients with HER-2 gene amplification was significantly worse than that without HER-2 gene amplification. In addition, oesophageal SCC patients with both HLA-A24-positive and HER-2-positive tumours (1+/2+/3+) accounted for 26% of these cases, and both HLA-A2- and HER-2-positive tumours accounted for 18% of them.
Subject(s)
Carcinoma, Squamous Cell/genetics , Esophageal Neoplasms/genetics , Gene Amplification , Gene Expression Profiling , Receptor, ErbB-2/biosynthesis , Receptor, ErbB-2/genetics , Aged , Aged, 80 and over , Carcinoma, Squamous Cell/pathology , Esophageal Neoplasms/pathology , Female , Follow-Up Studies , HLA Antigens , Haplotypes , Humans , Immunohistochemistry , Immunotherapy , In Situ Hybridization, Fluorescence , Male , Middle Aged , Reverse Transcriptase Polymerase Chain Reaction , Survival Analysis , T-Lymphocytes , VaccinationABSTRACT
Venous blood sera from children infected with Mycoplasma pneumoniae (MP) responded with a high titer to MP antibodies, affected healthy normal erythrocytes in vitro, and gave rise to changes in erythrocyte osmotic fragility. When serum was inactivated at 56 degrees C for 30 min or preincubated with anti-human C1 esterase inhibitor, the changes in the osmotic properties were suppressed at the lower level. The total sialic acid content and the intracellular ATP concentration of the treated erythrocytes were analyzed.
Subject(s)
Blood Proteins/physiology , Mycoplasma Infections/blood , Osmotic Fragility , Adenosine Triphosphatases/metabolism , Antibodies/immunology , Complement Activation , Erythrocytes/drug effects , Erythrocytes, Abnormal/classification , Erythrocytes, Abnormal/enzymology , Erythrocytes, Abnormal/physiology , Hot Temperature , Humans , Mycoplasma Infections/immunology , N-Acetylneuraminic Acid , Sialic Acids/bloodABSTRACT
A systematic experimental study on muon-catalyzed fusion was conducted using a series of solid deuterium and tritium mixtures. A variety of conditions were investigated, i.e., tritium concentrations from 20% to 70%, and temperatures from 5 to 16 K. With decreasing temperature, we observed an unexpected decrease in the muon cycling rate (lambda(c)) and an increase in the muon loss probability (W). The origins of these observed changes were interpreted by the temperature-dependence in the dt mu formation process for lambda(c) and that in the muon reactivation process after muon-to-alpha sticking for W.
ABSTRACT
Very large macrophages, which we have termed "giant macrophages" (G-M phi), have been found in renal tubules, some containing cytoplasmic vacuoles. To elucidate their pathophysiological roles, we examined renal biopsy tissues from various primary glomerulonephritis (GN) and tubulointerstitial nephritis (TIN) using immunohistochemistry with monoclonal antibodies against M phi and other cell surface markers. Giant macrophages were absent or rare in TIN, minimal change nephrotic syndrome, and minor glomerular abnormalities, but G-M phi was plentiful in progressive glomerulonephrides such as IgA nephropathy with crescents, membranoproliferative GN, focal segmental glomerulosclerosis, and especially in crescentic GN. These G-M phi were usually seen in the lumen of renal tubules, but occasionally were found in the Bowman's spaces and glomerular tufts, and similar cells were also found in urine. Moreover, they frequently made contact with tubular epithelial cells expressing intercellular adhesion molecule-1, and the tubular epithelial cells in such lesions often had degenerative changes. Giant M phi may damage tubular epithelial cells from the luminal side. Phenotypically, G-M phi showed activated (CD71+) and mature (25F9+) characteristics along with features of M phi (CD68+), and the cytoplasm contained a great deal of lipids. The numbers of G-M phi in renal tissues closely correlated with the degree of hematuria (rho = 0.5, P < 0.001), serum creatinine value (r = 0.63, P < 0.001) in GN patients (N = 96) and with proteinuria in IgA nephropathy patients (r = 0.89, P < 0.001, N = 27). These data suggest that G-M phi are M phi that were activated and matured in certain active inflammatory sites, which flowed into tubules and then into urine. Thus, the existence of G-M phi in biopsy tissue or urine reflect the activity of GN and may have a predictive value for the progression of GN.