Spin squeezing and quantum correlations

We discuss the notion of spin squeezing considering two mutually exclusive classes of spin-s states, namely, oriented and non-oriented states. Our analysis shows that the oriented states are not squeezed while non-oriented states exhibit squeezing. We also present a new scheme for construction of spin-s states using 2s spinors oriented along different axes. Taking the case of s=1, we show that the ‘non-oriented’ nature and hence squeezing arise from the intrinsic quantum correlations that exist among the spinors in the coupled state.     

New measurements of the masses of 15B and 19N

The neutron-rich nuclei ¹⁵B and ¹⁹N have been produced in reactions between ¹⁸O and ⁴⁸Ca. Mass excesses of 28.968 ± 0.025 MeV and 15.872 ± 0.020 MeV respectively were deduced from the reaction Q-values. These results are compared with previous measurements and theoretical predictions. Updated predictions using two different mass formulae are presented.     

Theory of sheath in a collisional multi-component plasma

The aim of this brief report is to study the behaviour of sheath structure in a multi-component plasma with dust-neutral collisions. The plasma consists of electrons, ions, micron size negatively charged dust particles and neutrals. The sheath-edge potential and sheath width are calculated for collisionally dominated sheath. Comparison of collisionless and collisionally dominated sheath are made.     

Partially ordered permutation groups

In this note we discuss permutation groups (G, ) in which the set admits aG-invariant order. By aG-invariant partial order (G-partial order) we mean a partial order < of such that < implies g<g, for all and in andg inG. If the set admits aG-partial order which is a total order, then (G, ) is an O-permutation group (orderable permutation group).The main concern of this paper is the development of a foundation for partially ordered permutation groups analogous to the existing one for partially ordered groups, as found in Fuchs [2].     

Synthesis and identification of small molecules that potently induce apoptosis in melanoma cells through G1 cell cycle arrest

Late-stage malignant melanoma is a cancer that is refractory to current chemotherapeutic treatments. The average survival time for patients with such a diagnosis is 6 months. In general, the vast majority of anticancer drugs operate through induction of cell cycle arrest and cell death in either the DNA synthesis (S) or mitosis (M) phase of the cell cycle. Unfortunately, the same mechanisms that melanocytes possess to protect cells from DNA damage often confer resistance to drugs that derive their toxicity from S or M phase arrest. Described herein is the synthesis of a combinatorial library of potential proapoptotic agents and the subsequent identification of a class of small molecules (triphenylmethylamides, TPMAs) that arrest the growth of melanoma cells in the G1 phase of the cell cycle. Several of these TPMAs are quite potent inducers of apoptotic death in melanoma cell lines (IC(50) approximately 0.5 muM), and importantly, some TPMAs are comparatively nontoxic to normal cells isolated from the bone marrow of healthy donors. Furthermore, the TPMAs were found to dramatically reduce the level of active nuclear factor kappa-B (NFkappaB) in the cell; NFkappaB is known to be constitutively active in melanoma, and this activity is critical for the proliferation of melanoma cells and their evasion of apoptosis. Compounds that reduce the level of NFkappaB and arrest cells in the G1 phase of the cell cycle can provide insights into the biology of melanoma and may be effective antimelanoma agents.     

Analysis of a shielded TE011 mode composite dielectric resonator for stable frequency reference

Analysis of a TE₀₁₁ mode composite sapphire-rutile dielectric resonator has been carried out to study the temperature variation of resonance frequency, close to the Cs atomic clock hyperfine frequency of 9.192 GHz. The complementary behavior of dielectric permittivity with temperature of the composite has been exploited to obtain the desired turning point in the resonant frequency. The frequency of the composite structure is found to be independent of the shield diameter beyond four times the puck diameter.     

The mass and low-lying levels of 40Cl

The mass excess of the T_z = 3 nucleus ⁴⁰Cl has been determined using the ⁴⁰Ar(⁷Li, ⁷Be)⁴⁰Cl reaction. A value ?27.527 ± 0.035 MeV was obtained. A number of excited states of ⁴⁰Cl were a1so observed. In addition, the ⁴⁰Ar(¹¹B, ¹¹C)⁴⁰Cl and ⁴⁰Ar(¹¹B, ¹³N)³⁸S reactions were investigated. Excited states of ³⁸S were observed at 1.28 ± 0.04 and 3.38 ± 0.10 MeV.     

Studies related to the total synthesis of pentostatin. Approaches to the synthesis of (8R)-3,6,7,8-tetrahydroimidazo-[4,5-d][1,3]diazepin-8-ol and N-3 alkyl congeners

A number of synthetic approaches to the (8R)-3,6,7,8-tetrahydroimidazo[4,5-d][1,3]diazepin-8-ol ring system ( 3 ) of pentostatin ( 1 ) are reported. These involve the synthesis of a number of 4-C-derivatives of N-alkyl-5-amino- and 5-nitro-1H-imidazoles derived from 4-methyl-5-nitro-1H-imidazole.     

Identification from a combinatorial library of a small molecule that selectively induces apoptosis in cancer cells

The selective induction of death in cancer cells is a major challenge in modern medicine. In this communication we describe the synthesis of an 88-membered combinatorial library, and the subsequent evaluation of these compounds for their ability to selectively induce apoptosis in cancerous cells. A compound was identified from the library that induces apoptosis in U-937 and HL-60 cell lines. This compound is a remarkably selective pro-apoptotic agent for these cancer cell lines, as it does not induce significant death in noncancerous white blood cells, even at concentrations as high as 1000 muM.