1,638 research outputs found
Problems of the rotating-torsion-balance limit on the photon mass
We discuss the problems (and the promise) of the ingenious method introduced
by Lakes, and recently improved on by Luo, to detect a possible small photon
mass by measuring the ambient magnetic vector potential from large scale
magnetic fields. We also point out how an improved ``indirect'' limit can be
obtained using modern measurements of astrophysical magnetic fields and plasmas
and that a good ``direct'' limit exists using properties of the solar wind.Comment: 4 pages, revised title and content
Pristine C60 fullereneS inhibit the rate of tumor growth and metastasis
Aim: To estimate the impact of C60 fullerene aqueous solution (C60FAS) on the rate of transplanted malignant tumor growth and metastasis. Methods: Lewis lung carcinoma was transplanted into С57Bl/6J male mice. Conventional methods for the evaluation of antitumor and antimetastatic effects have been used. Results: The C60FAS at low single therapeutic dose of 5 mg/kg inhibited the growth of transplanted malignant tumor (antitumor effect) and metastasis (antimetastatic effect): the maximum therapeutic effect was found to be of 76.5% for the tumor growth inhibition; the increase of animal life span by 22% was found; the metastasis inhibition index was estimated as 48%. Conclusion: It was found that water-soluble pristine С60 fullerenes efficiently inhibit the transplanted malignant tumor growth and metastasis
Powers of the Vandermonde determinant, Schur Functions, and recursive formulas
Since every even power of the Vandermonde determinant is a symmetric
polynomial, we want to understand its decomposition in terms of the basis of
Schur functions. We investigate several combinatorial properties of the
coefficients in the decomposition. In particular, we give recursive formulas
for the coefficient of the Schur function s_{\m} in the decomposition of an
even power of the Vandermonde determinant in variables in terms of the
coefficient of the Schur function s_{\l} in the decomposition of the same
even power of the Vandermonde determinant in variables if the Young diagram
of \m is obtained from the Young diagram of \l by adding a tetris type
shape to the top or to the left. An extended abstract containing the statement
of the results presented here appeared in the Proceedings of FPSAC11Comment: 23 pages; extended abstract appeared in the Proceedings of FPSAC1
Local Casimir Energy For Solitons
Direct calculation of the one-loop contributions to the energy density of
bosonic and supersymmetric phi-to-the-fourth kinks exhibits: (1) Local mode
regularization. Requiring the mode density in the kink and the trivial sectors
to be equal at each point in space yields the anomalous part of the energy
density. (2) Phase space factorization. A striking position-momentum
factorization for reflectionless potentials gives the non-anomalous energy
density a simple relation to that for the bound state. For the supersymmetric
kink, our expression for the energy density (both the anomalous and
non-anomalous parts) agrees with the published central charge density, whose
anomalous part we also compute directly by point-splitting regularization.
Finally we show that, for a scalar field with arbitrary scalar background
potential in one space dimension, point-splitting regularization implies local
mode regularization of the Casimir energy density.Comment: 18 pages. Numerous new clarifications and additions, of which the
most important may be the direct derivation of local mode regularization from
point-splitting regularization for the bosonic kink in 1+1 dimension
Effect of the visible light irradiation of fullerene containing composites on the ros generation and the viability of tumor cells
Aim: To study the effect of fullerene-containing composites, irradiated by visible light, on the radical oxygen species (ROS) generation in thymocytes, ascitic cells from Erlich’s tumor and leukemia cells L1210; to investigate viability of these cells in the presence of fullerene-containing composites under irradiation conditions. Materials and Methods: The viability of cells was evaluated by staining with 0.4% solution of the trypan blue; ROS were detected with the use of electron paramagnetic resonance (EPR) spectroscopy and spin traps; solutions of fullerene-containing composites were irradiated with mercury-vapor lamp. Results: We demonstrated that under irradiation conditions fullerene-containing composites increase the rate of ROS generation and decrease the number of viable tumor cells. Conclusions: The obtained data allow to consider the fullerene-containing composites as potential agents for photodynamic therapy.Цель: изучить влияние фуллеренсодержащих композитов, облученных видимым светом, на генерирование радикальных
форм кислорода (РФК) в клетках тимоцитов, асцитного рака Эрлиха и лейкоза L1210. Исследовать жизнеспособность
этих клеток в присутствии облученных фуллеренсодержащих композитов. Методы: жизнеспособность клеток определяли с
использованием 0,4 % раствора трипанового синего; РФК регистрировали методом ЭПР- спектроскопии и спиновых ловушек;
облучение водных раcтворов фуллеренсодержащих композитов в видимом диапазоне осуществляли с помощью ртутной
лампы. Результаты: показано, что фуллеренсодержащие композиты при облучении повышают скорость генерирования РФК
и уменьшают количество жизнеспособных опухолевых клеток. Выводы: полученные результаты позволяют рассматривать
фуллеренсодержащие композиты как потенциальные препараты для фотодинамической терапии
Hyperthermic effect of multi-walled carbon nanotubes stimulated with near infrared irradiation for anticancer therapy: in vitro studies
It is proposed to use the novel paradigm of treating cancer with hyperthermic therapy using multi-walled carbon nanotubes (MWCNT) stimulated with near infrared (NIR) irradiation. Aim: To establish the capacity of MWCNT stimulated with NIR irradiation to destroy Erlich ascitic carcinoma (EAC) cells. Materials and Methods: EAC cells suspension was irradiated with NIR heating lamp with a wavelength of 0.78–1.40 mm and power density of 3.5 W/cm2 over 1.5 min in the presence of MWCNT (0.1 mg/ml). The changes in the temperature of suspension with the NIR exposure time was measured using the differential cooper-constantan thermocouple. The viability of EAC cells was evaluated by trypan blue staining. Results: The death of 95.2% of EAC cells in the presence of MWCNT was observed after 1.5 min of NIR light irradiation: thermal ablation temperature was ~50 °C. Conclusions: It was demonstrated that addition of MWCNT to EAC cell suspension results in the photo-ablative destruction of cells exposed to short time NIR irradiation
Msh2 ATPase Activity Is Essential for Somatic Hypermutation at A-T Basepairs and for Efficient Class Switch Recombination
Somatic hypermutation (SHM) and class switch recombination (CSR) are initiated by activation-induced cytidine deaminase–mediated cytidine deamination of immunoglobulin genes. MutS homologue (Msh) 2−/− mice have reduced A-T mutations and CSR. This suggests that Msh2 may play a role in repairing activation-induced cytidine deaminase–generated G-U mismatches. However, because Msh2 not only initiates mismatch repair but also has other functions, such as signaling for apoptosis, it is not known which activity of Msh2 is responsible for the effects observed, and consequently, many models have been proposed. To further dissect the role of Msh2 in SHM and CSR, mice with a “knockin” mutation in the Msh2 gene that inactivates the adenosine triphosphatase domain were examined. This mutation (i.e., Msh2G674A), which does not affect apoptosis signaling, allows mismatches to be recognized but prevents Msh2 from initiating mismatch repair. Here, we show that, similar to Msh2−/− mice, SHM in Msh2G674A mice is biased toward G-C mutations. However, CSR is partially reduced, and switch junctions are more similar to those of postmeiotic segregation 2−/− mice than to Msh2−/− mice. These results indicate that Msh2 adenosine triphosphatase activity is required for A-T mutations, and suggest that Msh2 has more than one role in CSR
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