The simple and reversible control of the degree of polymerization, and thereby the bulk material properties, of a supramolecular polymer is reported. Noncovalent capping agents (chain stoppers) ...modulate the length of supramolecular polymers by stacking on the surfaces of the polymer’s ends. Methylene blue (MB) is a positively charged, planar polycyclic dye that acts as a chain stopper. It can be reversibly switched between its colored, planar, cationic state and a colorless, nonplanar, neutral state (leucomethylene blue, LMB) by reduction with ascorbic acid and then reoxidized to MB by O2. LMB does not act as a chain stopper. This behavior was utilized to reversibly trigger the gel to sol transformation of supramolecular polymers formed by the self-assembly of hexameric rosettes comprising 2,4,6-triaminopyrimidine and a hexanoic acid-substituted cyanuric acid (CyCo6) in aqueous media. The results of our experiments highlight the ability of this approach to reversibly switch between the gel and solution states of materials formed from supramolecular polymers and thereby control their bulk properties.
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IJS, KILJ, NUK, PNG, UL, UM, UPUK
Abstract
The J-PARC E16 experiment measures mass spectra of low-mass vector mesons,
ρ
,
ω
, and
ϕ
, in nuclei via
e
+
e
-
decays. Vector mesons are produced in
p
A reactions. A spectrometer with ...a large acceptance and a high-intensity beam up to 1
× 10
10
protons per ∼2-sec duration pulse are utilized to collect a sufficient number
of vector mesons. We have developed a spectrometer, which has two types of electron
identification detectors: a hadron blind detector (HBD) and a lead-glass calorimeter.
Commissioning runs have been performed at the J-PARC high-momentum beam line. The HBD
successfully observed on average 11 ± 1 photoelectrons for an incident electron. We achieved
the pion rejection of 0.9 ± 0.2% with the electron detection efficiency of 61 ± 4% for
the HBD, which was consistent of the expected performance.
The use of flipped-classroom methodology has increased recently in higher education. However, there is a lack of quantitative data on students' performance, especially in engineering courses. A ...flipped-classroom methodology has been developed in two different engineering degrees with 167 students. In both degrees also a control group with 156 students has been taught using the classical methodology. Through the data collected it is possible to measure the impact of learning (through the usual exams), to reduce the class absenteeism and to increase the exams attendance. Also, the students' implication with the new methodology can be checked by the use of YouTube analytics. The results show that the flipped-classroom model improves the results, at least in partial examinations. Furthermore, as the marks dispersion are lower, can be state that diversity has been treated in a better way.
Matrix acetylglutamate of uncoupled rat liver mitochondria increased about 10-fold, to 4.3 nmol/microliters, upon incubation with 5 mM concentrations of that compound. Uncoupled mitochondria ...incubated with the reagents needed for carbamyl phosphate and citrulline synthesis and 5 mM acetylglutamate synthesized citrulline at velocities which reached 99 nmol/min/mg of protein; simultaneously, as much as 47 nmol/min/mg of carbamyl phosphate accumulated and was distributed between matrix and medium. Maximal total carbamyl phosphate synthesis was, therefore, 146 nmol/min/mg, similar to the activity measured in liver homogenates. Without added acetylglutamate, some carbamyl phosphate accumulated when citrulline synthesis was about 40 nmol/min/mg. The finding that ornithine transcarbamylase can be limiting for citrulline synthesis shows that the activity of this enzyme is greatly restricted in mitochondria. The stimulation by ornithine of mitochondrial carbamyl phosphate synthesis was prevented when ornithine transcarbamylase was inhibited more than 96% by 5 mM delta-N-phosphonacetyl-L-ornithine, suggesting that the normal stimulatory effect of ornithine on carbamyl phosphate synthetase occurs via ornithine transcarbamylase. Lower concentrations of delta-N-phosphonacetyl-L-ornithine were required to achieve a given inhibition of citrulline synthesis from added carbamyl phosphate from endogenously synthesized carbamyl phosphate. The results reported suggest the existence of interactions between carbamyl phosphate synthetase and ornithine transcarbamylase in the matrix.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This paper studies the problem of scheduling a set of $n$ independent tasks on $m$ identical processors so as to minimize mean weighted flow-time. The problem is known to be NP-complete for $m \geqq ...2$ and to be NP-complete in the strong sense for m arbitrary. The worst case behavior of a heuristic algorithm which requires time $O(n\log n)$ is investigated, and it is shown that the mean weighted flow-time obtained by the algorithm does not exceed ${{(\sqrt 2 + 1)} / 2} \cong 1.0207$ times that of an optimal schedule. Moreover the bound ${{(\sqrt 2 + 1)} / 2}$ is best possible.
In this paper we consider a sex-fair matching in the stable marriage problem. The sex-fair stable matching defined in this paper has a property that the sum of the partner's rank of each man in his ...preference list is as close as possible to the sum of the partner's rank of each woman in her preference list. We transform the sex-fair marriage problem into a graph problem which is suitable for a genetic algorithm. We propose a genetic algorithm for the sex-fair stable matching. The transformation into the graph problem makes application of the GA easier and effective. Computer experiments show the effectiveness of the proposed genetic algorithm.
Experiments with carbamoyl phosphate synthetase (ammonia) in solution and in isolated mitochondria are reported which show the following. NH3 rather than NH4+ is the substrate of the enzyme. The ...apparent Km of NH3 for the purified enzyme is about 38 microM. The apparent Km for NH3 measured in intact isolated mitochondria is about 13 microM. This value was obtained for both coupled and uncoupled mitochondria and was unchanged when the rate of carbamoyl phosphate synthesis was increased 2-fold by incubating uncoupled mitochondria in the presence of 5 mM-N-acetylglutamate. According to the literature, the concentration of NH3 in liver is well below the measured apparent Km. On the basis of this and previous work we conclude that, quantitatively, changes in liver NH3 and ornithine are likely to be the most important factors in the fast regulation of synthesis of carbamoyl phosphate and urea. This conclusion is consistent with all available evidence obtained with isolated mitochondria, isolated hepatocytes, perfused liver and whole animals.
Experiments with carbamoyl phosphate synthetase (ammonia) in solution and in isolated mitochondria are reported which show the following. NH3 rather than NH4+ is the substrate of the enzyme. The ...apparent Km of NH3 for the purified enzyme is about 38 microM. The apparent Km for NH3 measured in intact isolated mitochondria is about 13 microM. This value was obtained for both coupled and uncoupled mitochondria and was unchanged when the rate of carbamoyl phosphate synthesis was increased 2-fold by incubating uncoupled mitochondria in the presence of 5 mM-N-acetylglutamate. According to the literature, the concentration of NH3 in liver is well below the measured apparent Km. On the basis of this and previous work we conclude that, quantitatively, changes in liver NH3 and ornithine are likely to be the most important factors in the fast regulation of synthesis of carbamoyl phosphate and urea. This conclusion is consistent with all available evidence obtained with isolated mitochondria, isolated hepatocytes, perfused liver and whole animals.
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