A pulsed source of continuous variable polarization entanglement

We have experimentally demonstrated polarization entanglement using continuous variables in an ultra-short pulsed laser system at telecommunication wavelengths. Exploiting the Kerr-nonlinearity of a glass fibre we generated a polarization squeezed pulse with S2 the only non-zero Stokes parameter thus S1 and S3 being the conjugate pair. Polarization entanglement was generated by interference of the polarization squeezed field with a vacuum on a 50:50 beam splitter. The two resultant beams exhibit strong quantum noise correlations in S1 and S3. The sum noise signal of S3 was at the respective shot noise level and the difference noise signal of S1 fell 2.9dB below this value

2-aryl-6-Polyfluoroalkyl-4-Pyrones as Promising Rf-Building-Blocks: Synthesis and Application for Construction of Fluorinated Azaheterocycles

A convenient and general method for the direct synthesis of 2-aryl-6-(trifluoromethyl)-4-pyrones and 2-aryl-5-bromo-6-(trifluoromethyl)-4-pyrones has been developed on the basis of one-pot oxidative cyclization of (E)-6-aryl-1,1,1-trifluorohex-5-ene-2,4-diones via a bromination/dehy-drobromination approach. This strategy was also applied for the preparation of 2-phenyl-6-polyfluoroalkyl-4-pyrones and their 5-bromo derivatives. Conditions of chemoselective enediones bromination were found and the key intermediates of the cyclization of bromo-derivatives to 4-pyrones were characterized. Synthetic application of the prepared 4-pyrones has been demonstrated for the construction of biologically important CF3-bearing azaheterocycles, such as pyra-zoles, pyridones, and triazoles. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: This research was funded by the Russian Science Foundation, grant number 18-13-00186

Polarization squeezing and continuous-variable polarization entanglement

The Stokes-parameter operators and the associated Poincare sphere, which describe the quantum-optical polarization properties of light, are defined and their basic properties are reviewed. The general features of the Stokes operators are illustrated by evaluation of their means and variances for a range of simple polarization states. Some of the examples show polarization squeezing, in which the variances of one or more Stokes parameters are smaller than the coherent-state value. The main object of the paper is the application of these concepts to bright squeezed light. It is shown that a light beam formed by interference of two orthogonally-polarized quadrature-squeezed beams exhibits squeezing in some of the Stokes parameters. Passage of such a primary polarization-squeezed beam through suitable optical components generates a pair of polarization-entangled light beams with the nature of a two-mode squeezed state. The use of pairs of primary polarization-squeezed light beams leads to substantially increased entanglement and to the generation of EPR-entangled light beams. The important advantage of these nonclassical polarization states for quantum communication is the possibility of experimentally determining all of the relevant conjugate variables of both squeezed and entangled fields using only linear optical elements followed by direct detection.Comment: 27 pages, including 10 figure

The PHENIX Experiment at RHIC

The physics emphases of the PHENIX collaboration and the design and current status of the PHENIX detector are discussed. The plan of the collaboration for making the most effective use of the available luminosity in the first years of RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program available at http://www.rhic.bnl.gov/phenix

ПЭТ-КТ с 11С-метионином в диагностике анапластических астроцитом и анапластических олигодендроглиом

The aim of this study was to evaluate average 11C-methionine uptake for grade II (anaplastic) gliomas in a large cohort, as well as relations between MRI and PET characteristics and their unfluence on overall and progression-free survival.Materials and methods. The study was based upon 78 patients with supratentorial tumors, among them 48 with anaplastic astrocytoma (AA) and 30 with anaplastic oligodendroglioma (AO). ALL patients underwent PET-CT with 11C-methionine and MRI study (Т1, Т2, Т2-FLAIR, DWI и 3D Т1+Gd regimes). Tumor removal was performed in 71 cases, stereotactic biopsy in 8 patients. Tumor specimen were assessed by neuropatomorphologists and IDH1-status and 1p/19q co-deletion were evaluated.Study results. AA IDH− tumors demonstrated statistically significant bigger metabolic volume and radiotracer uptake comparing with AA IDH+. Moreover, AA IDH − characterized by higher fractional MET uptake. The smallest tumors (by MRI) were AOs, meanwhile their fractional contrast enhancement was higher than for AAs. AOs were also known as tumors with minimal difference between MRI and PET-CT volume. MET uptake decreased in a row АА IDH− – АОД – AA IDH+, but the difference has not reached statistical significance. For wild-type AAs metabolic volume correlated with OS and PFS, meanwhile for IDH-mutant AAs tumor volume (measured by MRI) correlated only with PFS.Conclusion. Present study based on the largest cohort of patients with anaplastic gliomas who underwent both MRI and PET with 11C-methionine. It turned out, that unlike grade II oligodendogliomas, AOs do not always demonstrate higher than their astrocytic counterparts MET uptake levels.Цель исследования: определение усредненных показателей индекса накопления (ИН) радиофармпрепарата (РФП) (11С-метионина) в группе глиом Grade III на большом клиническом материале, а также изучение взаимосвязи показателей МРТ- и ПЭТ-исследований и значений ИН РФП с показателями общей и безрецидивной выживаемости.Материал и методы. В исследуемую группу вошло 78 пациентов, из них с диагнозом анапластическая астроцитома (АА) 48 (61,5%) пациентов и анапластическая олигодендроглиома (АОД) 30 (38,5%) пациентов; во всех случаях супратенториальной локализации. Всем пациентам выполнена ПЭТ-КТ с 11С-метионином по стандартной методике, а также МРТ в режимах Т1, Т2, Т2-FLAIR, DWI и 3D Т1+Gd. В 71 случае выполнено удаление опухоли, в 8 – верификация гистологического диагноза путем стереотаксической биопсии. Все опухоли подверглись молекулярно-генетическому анализу, в том числе с исследованием мутации IDH1 и ко-делеции 1p/19q.Результаты исследования. Метаболический объем опухоли и величина ИН РФП были статистически значимо выше в группе IDH-негативных АА, нежели в группе IDH-позитивных АА; кроме того, АА дикого типа продемонстрировали более высокие значения долевого накопления РФП. Наименьший общий объем опухоли по МРТ продемонстрировали АОД, при этом долевой объем контрастирования этих опухолей был значительно выше, чем в общей группе астроцитарных опухолей; для АОД характерно минимальное отличие общего объема опухоли от метаболического. Значения ИН РФП уменьшается в ряду АА IDH− – АОД – AA IDH+, однако эти различия не достигли статистически значимых величин. В группе IDH-негативных АА объем метаболически активной ткани по данным ПЭТ демонстрировал слабоотрицательную зависимость с общей и безрецидивной выживаемостью, а объем опухоли в группе IDH-мутантных АА коррелировад только с безрецидивной выживаемостью.Заключение. Настоящая работа на крупнейшем клиническом материале анализирует соотношения результатов МРТ и ПЭТ-КТ с 11С-метионином в группе глиом Grade III. На основании полученных данных удалось продемонстрировать неоднозначность зависимости значений ИН РФП в группе анапластических глиом от наличия олигодендрокомпонента в гистоструктуре опухоли, где, в отличие от глиом Grade II, не получено значимых отличий в уровне метаболической активности астроцитарных и олигодендроглиом, обе группы демонстрировали большой разброс показателей

Nonviral Approaches for Neuronal Delivery of Nucleic Acids

The delivery of therapeutic nucleic acids to neurons has the potential to treat neurological disease and spinal cord injury. While select viral vectors have shown promise as gene carriers to neurons, their potential as therapeutic agents is limited by their toxicity and immunogenicity, their broad tropism, and the cost of large-scale formulation. Nonviral vectors are an attractive alternative in that they offer improved safety profiles compared to viruses, are less expensive to produce, and can be targeted to specific neuronal subpopulations. However, most nonviral vectors suffer from significantly lower transfection efficiencies than neurotropic viruses, severely limiting their utility in neuron-targeted delivery applications. To realize the potential of nonviral delivery technology in neurons, vectors must be designed to overcome a series of extra- and intracellular barriers. In this article, we describe the challenges preventing successful nonviral delivery of nucleic acids to neurons and review strategies aimed at overcoming these challenges

Calcium Homeostasis and Cone Signaling Are Regulated by Interactions between Calcium Stores and Plasma Membrane Ion Channels

Calcium is a messenger ion that controls all aspects of cone photoreceptor function, including synaptic release. The dynamic range of the cone output extends beyond the activation threshold for voltage-operated calcium entry, suggesting another calcium influx mechanism operates in cones hyperpolarized by light. We have used optical imaging and whole-cell voltage clamp to measure the contribution of store-operated Ca2+ entry (SOCE) to Ca2+ homeostasis and its role in regulation of neurotransmission at cone synapses. Mn2+ quenching of Fura-2 revealed sustained divalent cation entry in hyperpolarized cones. Ca2+ influx into cone inner segments was potentiated by hyperpolarization, facilitated by depletion of intracellular Ca2+ stores, unaffected by pharmacological manipulation of voltage-operated or cyclic nucleotide-gated Ca2+ channels and suppressed by lanthanides, 2-APB, MRS 1845 and SKF 96365. However, cation influx through store-operated channels crossed the threshold for activation of voltage-operated Ca2+ entry in a subset of cones, indicating that the operating range of inner segment signals is set by interactions between store- and voltage-operated Ca2+ channels. Exposure to MRS 1845 resulted in ∼40% reduction of light-evoked postsynaptic currents in photopic horizontal cells without affecting the light responses or voltage-operated Ca2+ currents in simultaneously recorded cones. The spatial pattern of store-operated calcium entry in cones matched immunolocalization of the store-operated sensor STIM1. These findings show that store-operated channels regulate spatial and temporal properties of Ca2+ homeostasis in vertebrate cones and demonstrate their role in generation of sustained excitatory signals across the first retinal synapse