Three-body problem in a two-dimensional Fermi gas

We investigate the three-body properties of two identical "up" fermions and one distinguishable "down" atom interacting in a strongly confined two-dimensional geometry. We compute exactly the atom-dimer scattering properties and the three-body recombination rate as a function of collision energy and mass ratio m_up/m_down. We find that the recombination rate for fermions is strongly energy dependent, with significant contributions from higher partial waves at low energies. For m_up < m_down, the s-wave atom-dimer scattering below threshold is completely described by the scattering length. Furthermore, we examine the "up-up-down" bound states (trimers) appearing at large m_up/m_down and find that the energy spectrum for the deepest bound trimers resembles that of a hydrogen atom confined to two dimensions.Comment: 6 pages, 6 figure

Targeted therapies in the management of locally advanced and metastatic pancreatic cancer: a systematic review

Pancreatic cancer has a dismal prognosis particularly in patients presenting with unresectable tumors. We performed a bibliometric analysis of clinical trials for pancreatic cancer conducted between 2014-2016 focusing on patients that presented with unresectable (locally advanced or metastatic) tumors. We discuss a range of studies that employed FOLFIRINOX, the gemcitabine + nab-paclitaxel combination and studies that used molecularly-targeted therapy. Major areas of focus have been dual targeting of EGFR and VEGFR, immunotherapy or a multimodal approach – combining chemotherapy with radiotherapy. We also point out the need for molecular selection for low prevalence subtypes. Key insights sourced from these pivotal trials should improve clinical outcomes for this devastating cancer

Biologically-Active Gold(III) Complexes

A review is given of the background to and results of the succesful pharmacological testing of [AuX2(damp)] (X = Cl, OAc; damp = 2−Me2 NCH2C6 H4) against a range of microbes, fungi and tumouts, culminating in in vivo xenografts of ZR-1-75. These are the first fully evaluated gold(III) complexes. The activity and reactions of the diacetato-complex bear a resemblance to cisplatin, and some of the relevant chemistry is discussed. Preliminary screening data for C,P-chelated tertiary phosphine derivatives of gold(III) are presented

Bound states in a quasi-two-dimensional Fermi gas

We consider the problem of N identical fermions of mass M and one distinguishable particle of mass m interacting via short-range interactions in a confined quasi-two-dimensional (quasi-2D) geometry. For N=2 and mass ratios M/m<13.6, we find non-Efimov trimers that smoothly evolve from 2D to 3D. In the limit of strong 2D confinement, we show that the energy of the N+1 system can be approximated by an effective two-channel model. We use this approximation to solve the 3+1 problem and we find that a bound tetramer can exist for mass ratios M/m as low as 5 for strong confinement, thus providing the first example of a universal, non-Efimov tetramer involving three identical fermions.Comment: 5 pages, 4 figure

Supersolidity in electron-hole bilayers with a large density imbalance

We consider an electron-hole bilayer in the limit of extreme density imbalance, where we have a single particle in one layer interacting attractively with a Fermi liquid in the other parallel layer. Using an appropriate variational wave function for the dressed exciton, we provide strong evidence for the existence of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase in electron-hole bilayers with a large density imbalance. Furthermore, within this unusual limit of FFLO, we find that a dilute gas of minority particles forms excitons that condense into a two-dimensional "supersolid".Comment: 6 pages, 2 figure

Maintaining the quality of Western Australia\u27s oat harvest

WESTERN AUSTRALIA deservedly enjoys the reputation of being a producer of oats of high milling quality. Because of this, we have been able to develop valuable export markets which pay a premium for our oats. For some time Ballidu has been rated as the best milling oat in W.A. The work reported in this article indicates that other recommended varieties are equal to or better than Ballidu for milling

Dispersions of barium titanate in organic liquids

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1982.MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE.Includes bibliographical references.by Mark V. Parish.M.S

Preclinical detection of PrP\u3csup\u3eSc\u3c/sup\u3e in nictitating membrane lymphoid tissue of sheep

SHEEP scrapie is the prototype of a heterogeneous group of transmissible spongiform encephalopathies (TSES) which occur in humans, cattle, cats, mink and cervids. TSEs are characterised by the deposition of prion proteins (Prp-Scrapie or PrpSc) in the central nervous system of affected individuals (Prusiner 1982). PrPSc and infectivity have also been detected in the lymphoreticular system of sheep well before symptoms occur (Hadlow and others 1982, Race and others 1992). Detection of PrpSc in lymphoid tissue, such as tonsils or peripheral lymph nodes, has been proposed as a preclinical diagnostic test for scrapie (Ikegami and others 1991, Schreuder and others 1996). This short communication reports the use of a non-invasive diagnostic assay based on biopsy of lymphoid nodules in the nictitating membrane of sheep. The nictitating membrane or third eyelid (palpebra tertia) of ruminant animals consists of a cartilaginous sheet with superficial lymphoid follicles and a seromucinous secretory gland beneath the conjunctiva of the bulbar surface (Slatter and Mills 1981). The lymphoid nodules are easily biopsied under local anaesthesia. Sheep were pretreated by topical administration of proparacaine hydrochloride (Ophthetic; Allergan) and the nictitating membrane was everted with disposable 1 x 2-toothed, 5½-inch forceps (Sklar 78055-1). Typically two clusters of lymphoid tissue were visualised above the more pale glandular tissue. A biopsy of one cluster of lymphoid tissue was collected using disposable Metzenbaum scissors (Sklar 30455) and a second set of forceps. Biopsied tissue was fixed in formalin and paraffin embedded using conventional methods. Sections typically contained four to seven lymphoid follicles

Fulde-Ferrell-Larkin-Ovchinnikov states in one-dimensional spin-polarized ultracold atomic Fermi gases

We present a systematic study of quantum phases in a one-dimensional spin-polarized Fermi gas. Three comparative theoretical methods are used to explore the phase diagram at zero temperature: the mean-field theory with either an order parameter in a single-plane-wave form or a self-consistently determined order parameter using the Bogoliubov-de Gennes equations, as well as the exact soluble Bethe ansatz method. We find that a spatially inhomogeneous Fulde-Ferrell-Larkin-Ovchinnikov phase, which lies between the fully paired BCS state and the fully polarized normal state, dominates most of the phase diagram of a uniform gas. The phase transition from the BCS state to the Fulde-Ferrell-Larkin-Ovchinnikov phase is of second order, and therefore there are no phase separation states in one-dimensional homogeneous polarized gases. This is in sharp contrast to the three-dimensional situation, where a phase separation regime is predicted to occupy a very large space in the phase diagram. We conjecture that the prediction of the dominance of the phase separation phases in three dimension could be an artifact of the non-self-consistent mean-field approximation, which is heavily used in the study of three-dimensional polarized Fermi gases. We consider also the effect of a harmonic trapping potential on the phase diagram, and find that in this case the trap generally leads to phase separation, in accord with the experimental observations for a trapped gas in three dimension. We finally investigate the local fermionic density of states of the Fulde-Ferrell-Larkin-Ovchinnikov ansatz. A two-energy-gap structure is shown up, which could be used as an experimental probe of the Fulde-Ferrell-Larkin-Ovchinnikov states.Comment: 22 papes, 19 figure