Residues and Topological Yang-Mills Theory in Two Dimensions

A residue formula which evaluates any correlation function of topological $SU_n$ Yang-Mills theory with arbitrary magnetic flux insertion in two dimensions are obtained. Deformations of the system by two form operators are investigated in some detail. The method of the diagonalization of a matrix valued field turns out to be useful to compute various physical quantities. As an application we find the operator that contracts a handle of a Riemann surface and a genus recursion relation.Comment: 23 pages, some references added, to appear in Rev.Math.Phy

Astrocytes mediate neurovascular signaling to capillary pericytes but not to arterioles

Active neurons increase their energy supply by dilating nearby arterioles and capillaries. This neurovascular coupling underlies blood oxygen level-dependent functional imaging signals, but its mechanism is controversial. Canonically, neurons release glutamate to activate metabotropic glutamate receptor 5 (mGluR5) on astrocytes, evoking Ca(2+) release from internal stores, activating phospholipase A2 and generating vasodilatory arachidonic acid derivatives. However, adult astrocytes lack mGluR5, and knockout of the inositol 1,4,5-trisphosphate receptors that release Ca(2+) from stores does not affect neurovascular coupling. We now show that buffering astrocyte Ca(2+) inhibits neuronally evoked capillary dilation, that astrocyte [Ca(2+)]i is raised not by release from stores but by entry through ATP-gated channels, and that Ca(2+) generates arachidonic acid via phospholipase D2 and diacylglycerol kinase rather than phospholipase A2. In contrast, dilation of arterioles depends on NMDA receptor activation and Ca(2+)-dependent NO generation by interneurons. These results reveal that different signaling cascades regulate cerebral blood flow at the capillary and arteriole levels

Subtleties in QCD theory in Two Dimensions

It is shown that in a formulation of Yang-Mills theory in two dimensions in terms of A=if^{-1}\pa f, \bar A=i\bar f\bpa\bar f^{-1} with $f(z,\bar z)$, $\bar f(z,\bar z)\in[SU(N_C)]^c$ the complexification of $SU(N_C)$ , reveals certain subtleties. ``Physical" massive color singlet states seem to exist. When coupled to $N_F$ quarks the coupling constant is renormalized in such a way that it vanishes for the pure Yang- Mills case. This renders the above states massless and unphysical. In the abelian case, on the other hand, the known results of the Schwinger model are reproduced with no need of such a renormalization. The massless $QCD_2$ theory is analyzed in similar terms and peculiar massive states appear, with a mass of $e_c\sqrt {N_F \over 2\pi}$.Comment: 21 page

K+ efflux through postsynaptic NMDA receptors suppresses local astrocytic glutamate uptake

Glutamatergic transmission prompts K+ efflux through postsynaptic NMDA receptors. The ensuing hotspot of extracellular K+ elevation depolarizes presynaptic terminal, boosting glutamate release, but whether this also affects glutamate uptake in local astroglia has remained an intriguing question. Here, we find that the pharmacological blockade, or conditional knockout, of postsynaptic NMDA receptors suppresses use-dependent increase in the amplitude and duration of the astrocytic glutamate transporter current (IGluT), whereas blocking astrocytic K+ channels prevents the duration increase only. Glutamate spot-uncaging reveals that astrocyte depolarization, rather than extracellular K+ rises per se, is required to reduce the amplitude and duration of IGluT. Biophysical simulations confirm that local transient elevations of extracellular K+ can inhibit local glutamate uptake in fine astrocytic processes. Optical glutamate sensor imaging and a two-pathway test relate postsynaptic K+ efflux to enhanced extrasynaptic glutamate signaling. Thus, repetitive glutamatergic transmission triggers a feedback loop in which postsynaptic K+ efflux can transiently facilitate presynaptic release while reducing local glutamate uptake

Voltammetry of the complexes of the platinum metals with organic sulphides in acetonitrile

The electrochemical behaviour of palladium(II), ruthenium(III), rhodium(III), osmium(IV), iridium(IV) and platinum(IV) complexes with a number of sulphides was investigated at a glassy carbon electrode in acetonitrile. Complexes of Ru(III), Os(IV) and Ir(IV) have been found to undergo a reversible one-electron transfer yielding Ru(II), Os(III) and Ir(III) complexes. Electroreduction of the Ru(II) and Ir(III) compounds is of the EC type and is accompanied by the rearrangement of the complex coordination sphere. Compounds of Pd(II), Rh(III) and Pt(IV) are reduced with the transfer of 2 electrons in the first stage. The electrode process differs from a reversible one and is complicated by the dissociation reaction of the ligands. The influence of the nature of the donor atoms on the oxidation potentials of the complexes is considered. © 1988

PHARMACOECONOMICAL RESEARCH OF THE USE OF SORAFENIB IN MALIGNANT TUMORS

Purpose. Pharmacoeconomic rationale for the use of sorafenib in malignant tumors in comparison with drugs that are included in the list of pharmaceuticals to provide to certain categories of citizens.Method of the study. Pharmacoeconomic rationale for the use of sorafenib in this study is made by analyzing the impact on the budget. The calculated costs of treatment with sorafenib at a hypothetical group of 100 patients with metastatic renal cell carcinoma (MRCC), hepatocellular carcinoma (HCC) and differentiated thyroid cancer resistant to radioactive iodine (DCT). These costs were compared with costs of treatment of a similar group of 100 patients, with treatment of MRCC applied bevacizumab (original or generic) in combination with interferon α, and patients with HCC and DCT were excluded from receiving drugs from a program of providing with necessary medicines (PNM). As a result the potential economic effect of the inclusion of sorafenib in the list of PNM was calculated.Results. Treatment of MRCC is cheaper with the use of sorafenib compared to bevacizumab in combination with interferon α: savings is 592 878 rubles in the original use of bevacizumab and 274 976 rubles in the use of generic bevacizumab for one patient-year. If we use sorafenib in a group of 100 people with MRCC, HCC and DCT suitable for treatment with sorafenib, the overall expenses are more than 175 million rubles, while using the original combination of bevacizumab with interferon α – more than 204 million rubles, and in the application of the generic combination of bevacizumab with interferon α – more than 176 million rubles, while in the two last cases the treatment of patients with HCC and DCT is not carried out. The total amount of annual budget savings in the treatment of 100 patients is more than 28.5 million rubles at the account of original of bevacizumab or more than 1 million rubles in accounting of generic bevacizumab.Conclusion. The inclusion of the targeted drug sorafenib in the list of pharmaceuticals to provide certain categories of citizens is economically justified. The use of sorafenib, instead of the combination of bevacizumab + interferon-α in patients with MRCC gives us the opportunity to release the funds and provide a systemic treatment of patients with other malignancies (HCC, DCT) while reducing the burden on the budget

Structural and magnetic studies of FE100–xCox nanotubes obtaine by template method

Hollow nanostructures based on the Fe100–xCox alloy were synthesized in the pores of polymer template matrices based on PET using the electrochemical deposition method. Morphology, elemental composition, and structural features were characterized by scanning electron microscopy, energy dispersive analysis, and X-ray diffractometry. The study of the internal magnetic texture was carried out using Mossbauer spectroscopy. The dependence of the change in structural and magnetic properties from the atomic content of components in nanotube structure is revealed. It is established that the synthesized nanostructures are hollow Fe100–xCox nanotubes with a body-centered cubic crystal structure. The decrease in the unit cell parameter with increasing cobalt concentration is due to the difference in the radii of Fe (1.227 Å) and Co (1.191 Å) atoms. It is established that a random distribution of magnetic moments directions of Fe atoms is observed for Fe100Co0 nanotubes. And magnetic texture along the nanotube axis is observed for Fe100–xCox nanotubes, with an increase in Co atoms concentration. The average angle between the direction of the magnetic moment of iron atoms and the nanotube axis decreases from v = 54:6° to v = 24:5°. © 2018, Electromagnetics Academy. All rights reserved

Template synthesis and magnetic characterization of FeNi nanotubes

Iron-nickel nanotubes consisting of 20% Ni and 80% Fe with an aspect ratio of about 100 were synthesized by electrochemical deposition in the pores of polyethylene terephthalate ion-track membranes. The main morphological parameters such as composition, wall thickness and structural characteristics were defined. Macro- and micromagnetic parameters of FeNi nanotubes were determined. © 2017, Electromagnetics Academy. All rights reserved

Density Correlation Functions in Calogero Sutherland Models

Using arguments from two dimensional Yang-Mills theory and the collective coordinate formulation of the Calogero-Sutherland model, we conjecture the dynamical density correlation function for coupling $l$ and $1/l$, where $l$ is an integer. We present overwhelming evidence that the conjecture is indeed correct.Comment: 12 pages phyzzx, CERN-TH/94.7243 One reference change