1,505 research outputs found
Echo Path Transfer Function Estimation for Spectral Subtraction-based Acoustic Echo Suppression
In this study, we propose a novel technique for spectral subtraction (SS)-based acoustic echo suppression (AES). Conventional AES methods based on SS apply fixed weights to the estimated echo path transfer function (EPTF) at the current signal segment and to the EPTF estimated until the previous time interval. We propose a new EPTF estimation approach that adaptively updates the weight parameters in response to abrupt changes in the acoustic environment. From the experiments, we conclude that the developed techniques can be successfully used for the SS-based AES systems
Ultrasound of the Urinary Bladder, Revisited
Urine-filled bladder can be evaluated easily with ultrasound, and bladder tumors are usually well shown at ultrasound. Although ultrasound is not a primary imaging modality for staging of bladder tumors, it can provide general information regarding depth of tumor invasion into the proper muscle or perivesical adipose tissue. Ultrasound is also useful in showing nonneoplastic lesions of the bladder, such as stone, cystitis, diverticulum and ureterocele. Color Doppler ultrasound can show vascularity of the tumor. It also shows urine flow from the ureteral orifice or through the diverticular neck. As compared with transabdominal ultrasound, transrectal ultrasound shows bladder lesions more markedly in the dorsal wall or neck of the bladder
The Biological Safety of Stainless Steel Needles Used in Warm-needling
Warm-needling (also called thermo-acupuncture) is a combination of acupuncture and moxibustion. Due to the intense heat involved, there have been concerns over the biological safety of the acuneedles used in the treatment. This paper reports two phases of a safety test. For a preliminary test, we compared the temperature change patterns of stainless steel (SS304) needles and traditional gold alloy needles, which have been increasingly replaced by the former. To verify the effects of the presence of coating materials, the main test involved three different kinds of SS304: silicone-coated, salicylic acid-coated and non-coated needles. Each group of needles was tested for pH level, heavy metals and UV absorbance spectrum along with biological tests on the cytotoxicity and hemolysis of the needle. All the tests on the extractants from the needles were negative. In the biological tests, each test result showed a significant difference from the positive control samples, while no significant difference was observed compared with the negative control samples. In the hemolysis tests, all samples satisfied the Korean Government Standards. All the results suggest that SS304 needles are biologically safe to be used in warm-needling, though they can be improved to perform as well as the gold alloy needles in terms of temperature fluctuations
In-situ fabrication of cobalt-doped SrFe2As2 thin films by using pulsed laser deposition with excimer laser
The remarkably high superconducting transition temperature and upper critical
field of iron(Fe)-based layered superconductors, despite ferromagnetic material
base, open the prospect for superconducting electronics. However, success in
superconducting electronics has been limited because of difficulties in
fabricating high-quality thin films. We report the growth of high-quality
c-axis-oriented cobalt(Co)-doped SrFe2As2 thin films with bulk
superconductivity by using an in-situ pulsed laser deposition technique with a
248-nm-wavelength KrF excimer laser and an arsenic(As)-rich phase target. The
temperature and field dependences of the magnetization showing strong
diamagnetism and transport critical current density with superior Jc-H
performance are reported. These results provide necessary information for
practical applications of Fe-based superconductors.Comment: 8 pages, 3figures. to be published at Appl. Phys. Let
The biological significance of non-enzymatic reaction of menadione with plasma thiols: enhancement of menadione-induced cytotoxicity to platelets by the presence of blood plasma
AbstractTo test the hypothesis that the non-enzymatic reaction of quinones with thiols in plasma can generate reactive oxygens (ROS), thereby leading to potentiated cellular toxicity, we have studied the effect of a representative quinone compound, menadione, on plasma isolated from rats. The experimental results are as follows: (1) menadione generated ROS via non-enzymatic reaction with protein thiols in plasma; (2) the presence of plasma increased menadione-induced cytotoxicity to platelets; (3) pretreatment of plasma with a thiol-depleting agent significantly suppressed menadione-induced ROS and cytotoxicity. These results suggest that the non-enzymatic reaction of menadione with plasma thiols could be an important process in quinone-induced cellular toxicity
Degree distributions under general node removal: Power-law or Poisson?
Perturbations made to networked systems may result in partial structural
loss, such as a blackout in a power-grid system. Investigating the resultant
disturbance in network properties is quintessential to understand real networks
in action. The removal of nodes is a representative disturbance, but previous
studies are seemingly contrasting about its effect on arguably the most
fundamental network statistic, the degree distribution. The key question is
about the functional form of the degree distributions that can be altered
during node removal or sampling, which is decisive in the remaining
subnetwork's static and dynamical properties. In this work, we clarify the
situation by utilizing the relative entropies with respect to the reference
distributions in the Poisson and power-law form. Introducing general sequential
node removal processes with continuously different levels of hub protection to
encompass a series of scenarios including random removal and preferred or
protective removal of the hub, we classify the altered degree distributions
starting from various power-law forms by comparing two relative entropy values.
From the extensive investigation in various scenarios based on direct
node-removal simulations and by solving the rate equation of degree
distributions, we discover in the parameter space two distinct regimes, one
where the degree distribution is closer to the power-law reference distribution
and the other closer to the Poisson distribution.Comment: 12 pages, 7 figure
Discovery and Genetic Characterization of Novel Paramyxoviruses Related to the Genus Henipavirus in Crocidura Species in the Republic of Korea
Paramyxoviruses, negative-sense single-stranded RNA viruses, pose a critical threat to
human public health. Currently, 78 species, 17 genera, and 4 subfamilies of paramyxoviruses are harbored by multiple natural reservoirs, including rodents, bats, birds, reptiles, and fish. Henipaviruses
are critical zoonotic pathogens that cause severe acute respiratory distress and neurological diseases
in humans. Using reverse transcription-polymerase chain reaction, 115 Crocidura species individuals
were examined for the prevalence of paramyxovirus infections. Paramyxovirus RNA was observed in
26 (22.6%) shrews collected at five trapping sites, Republic of Korea. Herein, we report two genetically
distinct novel paramyxoviruses (genus: Henipavirus): Gamak virus (GAKV) and Daeryong virus
(DARV) isolated from C. lasiura and C. shantungensis, respectively. Two GAKVs and one DARV were
nearly completely sequenced using next-generation sequencing. GAKV and DARV contain six genes
(30
-N-P-M-F-G-L-50
) with genome sizes of 18,460 nucleotides and 19,471 nucleotides, respectively.
The phylogenetic inference demonstrated that GAKV and DARV form independent genetic lineages
of Henipavirus in Crocidura species. GAKV-infected human lung epithelial cells elicited the induction
of type I/III interferons, interferon-stimulated genes, and proinflammatory cytokines. In conclusion,
this study contributes further understandings of the molecular prevalence, genetic characteristics
and diversity, and zoonotic potential of novel paramyxoviruses in shrews
- …