74 research outputs found
Permeability of the fish intestinal membrane to bulky chemicals
The ability to predict the environmental behavior of chemicals precisely is important for realizing more rational regulation. In this study, the bioaccumulation of nine chemicals of different molecular weights absorbed via the intestinal tract was evaluated in fish using the everted gut sac method. The amounts of chemicals that passed through the intestinal membrane after a 24-hr exposure were significantly decreased for chemicals with MW≥548 and Dmax min≥15.8 Å (or Dmax aver≥17.2 Å). These thresholds are consistent with those previously proposed in terms of MW (>800) and molecular size (Dmax min>15.6 Å or Dmax aver>17.1 Å) for the limit of permeable chemicals through the gill membrane. The results show that the same MW and Dmax criteria can be used to predict low bioaccumulation through both the gill membrane and the intestinal tract. These findings are helpful in reducing the need to conduct animal tests in environmental safety studies
Criterion of molecular size to evaluate the bioaccumulation potential of chemicals in fish
To evaluate the bioaccumulation potential of chemicals in fish, a molecular-size descriptor, Dmax aver, has been used as a weight of evidence under the EU REACH. The Dmax aver value, however, is estimated on the basis of 3-D structures of possible stable conformers in a vacuum using OASIS software that requires expertise upon parameter input. We developed a method to calculate the 3-D conformers in water, which is more suitable for bioaccumulation potential evaluation in an aquatic environment, by introducing MD simulation. By examining the relationship of the calculated molecular size of 1665 chemicals with their reported BCF values, we found that 17.1 Å of Dmax aver or 15.6 Å of Dmax min was a threshold of molecular size in water to predict the low bioaccumulation (i.e., BCF<5000) of a chemical. Setting this threshold as a new standard would reduce the number of animal tests without compromising the quality of safety evaluation
AQT-D: Demonstration of the Water Resistojet Propulsion System by the ISS-Deployed CubeSat
AQT-D (AQua Thruster-Demonstrator) is a 3U CubeSat for a demonstration of a water resistojet propulsion system developed by The University of Tokyo. AQT-D installed the 1U propulsion system using water as a propellant, named AQUARIUS-1U (AQUA ResIstojet propUlsion System 1U). We completed the design and assembly of the AQT-D flight model. AQUARIUS-1U was fired on a pendulum-type thrust balance, and its performance was directly characterized in both a stand-alone test and an integrated test using an entire spacecraft system. AQT-D is currently scheduled to be delivered to JAXA in July 2019 and launched to the International Space Station (ISS) in the middle of 2019 by the H-IIB rocket. AQT-D will be deployed from the Japanese Experiment Module (JEM), known as Kibo, and demonstrate water propulsion technology
Is the combination therapy of IKr-channel blocker and left stellate ganglion block effective for intractable ventricular arrhythmia in a cardiopulmonary arrest patient?
Background: We have previously reported that the defibrillation success rate of intravenous nifekalant
hydrochloride (NIF), a pure IKr-channel (IKr: the rapid components of the delayed rectifier potassium
current) blocker, was more than 75% for lidocaine-resistant ventricular tachycardia and fibrillation
(VT/VF) in patients with out-of-hospital cardiopulmonary arrest (CPA). However, there was no
effective treatment for the remaining 25% of patients in whom defibrillation was unsuccessful. We
hypothesised that the combination therapy of NIF and left stellate ganglion block (LSGB) was useful for
defibrillation in NIF-resistant VT/VF and investigated its efficacy in a retrospective study.
Methods and results: We investigated sequentially 272 out-of-hospital CPA patients treated
at Tokai University between April and December 2006. VT/VF occurred in 55 patients on
arrival or during cardiopulmonary resuscitation (CPR). On the basis of our CPR algorithm,
NIF was administered (0.15-0.3 mg/kg, i.v.) after the first direct-current cardioversion.
NIF-resistant VT/VFs were observed in 15 out of 55 patients and LSGB was performed on
11 of these with administration of NIF. Sinus rhythm was restored in 7 patients following
LSGB (64%) and complete recovery was achieved in 2 patients. In the non-LSGB group,
however, all the patients died.
Conclusions: The combination therapy of intravenous NIF and LSGB was useful for defibrillation
in intractable VT/VF. It is a potential and innovative treatment strategy for
IKr-channel blocker resistant VT/VF. (Cardiol J 2007; 14: 355-365
Skuteczność terapii złożonej polegającej na podaniu blokera kanału IKr oraz wykonaniu blokady zwoju gwiaździstego w leczeniu opornych arytmii komorowych u chorych z zatrzymaniem krążenia
Wstęp: W poprzednich doniesieniach autorzy niniejszej pracy dowiedli, że współczynnik
skuteczności defibrylacji przy jednoczesnym dożylnym podaniu chlorowodorku nifekalantu
(NIF) - selektywnego blokera kanałów szybkiej składowej opóźnionego prostującego prądu
potasowego (IKr) wynosił powyżej 75% dla opornego na lignokainę częstoskurczu lub migotania
komór (VT/VF) w przebiegu pozaszpitalnego zatrzymania krążenia (CPA). Jednakże dla
pozostałych 25% chorych, u których wykonana defibrylacja okazała się nieskuteczna, nie
znaleziono efektywnych metod leczenia. Autorzy niniejszej pracy sugerują, że zastosowanie złożonej
terapii polegającej na dożylnym podaniu NIF oraz wykonaniu blokady lewego zwoju gwiaździstego
(LSGB) jest użyteczne w przypadku defibrylacji VT/VF opornego na działanie NIF. Na podstawie
własnych badań retrospektywnych podjęto także próbę oceny skuteczności tej terapii.
Metody i wyniki: Do badania włączono kolejnych 272 chorych przyjętych do Kliniki Kardiologii
Uniwersytetu Tokai w okresie od kwietnia do grudnia 2006 roku z powodu pozaszpitalnego
zatrzymania krążenia. U 55 pacjentów (podczas przyjęcia lub też w przebiegu resuscytacji
krążeniowo-oddechowej) stwierdzono VT/VF. Zgodnie z samodzielnie wypracowanymi przez
autorów pracy algorytmami prowadzenia resuscytacji krążeniowo-oddechowej NIF (w dawce
0,15-0,3 mg/kg) podawano dożylnie po pierwszej próbie kardiowersji. Oporne na działanie NIF częstoskurcze komorowe/migotania komór wystąpiły u 15 spośród 55 pacjentów.
U 11 chorych z powyższej grupy wykonano LSGB oraz podano dożylnie NIF. U 7 osób (64%)
po zabiegu LSGB uzyskano powrót rytmu zatokowego. Całkowity powrót do zdrowia zanotowano
u 2 chorych. Jednakże w grupie, w której nie wykonano zabiegu blokady lewego zwoju
gwiaździstego (grupa nie-LSBG), zmarli wszyscy pacjenci.
Wnioski: Terapia złożona polegająca na dożylnym podaniu NIF oraz wykonaniu LSGB
okazała się użyteczna w przypadku defibrylacji opornego VT/VF. Jest to potencjalna i innowacyjna
strategia leczenia opornego na selektywne blokery kanałów IKr częstoskurczu komorowego/
migotania komór. (Folia Cardiologica Excerpta 2007; 2: 524-536
Coincidence analysis to search for inspiraling compact binaries using TAMA300 and LISM data
Japanese laser interferometric gravitational wave detectors, TAMA300 and
LISM, performed a coincident observation during 2001. We perform a coincidence
analysis to search for inspiraling compact binaries. The length of data used
for the coincidence analysis is 275 hours when both TAMA300 and LISM detectors
are operated simultaneously. TAMA300 and LISM data are analyzed by matched
filtering, and candidates for gravitational wave events are obtained. If there
is a true gravitational wave signal, it should appear in both data of detectors
with consistent waveforms characterized by masses of stars, amplitude of the
signal, the coalescence time and so on. We introduce a set of coincidence
conditions of the parameters, and search for coincident events. This procedure
reduces the number of fake events considerably, by a factor
compared with the number of fake events in single detector analysis. We find
that the number of events after imposing the coincidence conditions is
consistent with the number of accidental coincidences produced purely by noise.
We thus find no evidence of gravitational wave signals. We obtain an upper
limit of 0.046 /hours (CL ) to the Galactic event rate within 1kpc from
the Earth. The method used in this paper can be applied straightforwardly to
the case of coincidence observations with more than two detectors with
arbitrary arm directions.Comment: 28 pages, 17 figures, Replaced with the version to be published in
Physical Review
Results of the search for inspiraling compact star binaries from TAMA300's observation in 2000-2004
We analyze the data of TAMA300 detector to search for gravitational waves
from inspiraling compact star binaries with masses of the component stars in
the range 1-3Msolar. In this analysis, 2705 hours of data, taken during the
years 2000-2004, are used for the event search. We combine the results of
different observation runs, and obtained a single upper limit on the rate of
the coalescence of compact binaries in our Galaxy of 20 per year at a 90%
confidence level. In this upper limit, the effect of various systematic errors
such like the uncertainty of the background estimation and the calibration of
the detector's sensitivity are included.Comment: 8 pages, 4 Postscript figures, uses revtex4.sty The author list was
correcte
The Japanese space gravitational wave antenna; DECIGO
DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future
Japanese space gravitational wave antenna. DECIGO is expected to open a new window of
observation for gravitational wave astronomy especially between 0.1 Hz and 10 Hz, revealing
various mysteries of the universe such as dark energy, formation mechanism of supermassive
black holes, and inflation of the universe. The pre-conceptual design of DECIGO consists of
three drag-free spacecraft, whose relative displacements are measured by a differential Fabry–
Perot Michelson interferometer. We plan to launch two missions, DECIGO pathfinder and pre-
DECIGO first and finally DECIGO in 2024
Observation results by the TAMA300 detector on gravitational wave bursts from stellar-core collapses
We present data-analysis schemes and results of observations with the TAMA300
gravitational-wave detector, targeting burst signals from stellar-core collapse
events. In analyses for burst gravitational waves, the detection and
fake-reduction schemes are different from well-investigated ones for a
chirp-wave analysis, because precise waveform templates are not available. We
used an excess-power filter for the extraction of gravitational-wave
candidates, and developed two methods for the reduction of fake events caused
by non-stationary noises of the detector. These analysis schemes were applied
to real data from the TAMA300 interferometric gravitational wave detector. As a
result, fake events were reduced by a factor of about 1000 in the best cases.
The resultant event candidates were interpreted from an astronomical viewpoint.
We set an upper limit of 2.2x10^3 events/sec on the burst gravitational-wave
event rate in our Galaxy with a confidence level of 90%. This work sets a
milestone and prospects on the search for burst gravitational waves, by
establishing an analysis scheme for the observation data from an
interferometric gravitational wave detector
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