Synthesis of New Bitopic Tetra(pyrazolyl)-Ligands with Neopentane and O-Xylene Backbones

Several new bitopic pyrazole-containing ligands were prepared from the corresponding pyrazoles and tetrahalogen or tetratosyloxy derivatives of o-xylene and neopentane in a superbasic medium (KOH-DMSO)

Demonstrating Quantum Error Correction that Extends the Lifetime of Quantum Information

The remarkable discovery of Quantum Error Correction (QEC), which can overcome the errors experienced by a bit of quantum information (qubit), was a critical advance that gives hope for eventually realizing practical quantum computers. In principle, a system that implements QEC can actually pass a "break-even" point and preserve quantum information for longer than the lifetime of its constituent parts. Reaching the break-even point, however, has thus far remained an outstanding and challenging goal. Several previous works have demonstrated elements of QEC in NMR, ions, nitrogen vacancy (NV) centers, photons, and superconducting transmons. However, these works primarily illustrate the signatures or scaling properties of QEC codes rather than test the capacity of the system to extend the lifetime of quantum information over time. Here we demonstrate a QEC system that reaches the break-even point by suppressing the natural errors due to energy loss for a qubit logically encoded in superpositions of coherent states, or cat states of a superconducting resonator. Moreover, the experiment implements a full QEC protocol by using real-time feedback to encode, monitor naturally occurring errors, decode, and correct. As measured by full process tomography, the enhanced lifetime of the encoded information is 320 microseconds without any post-selection. This is 20 times greater than that of the system's transmon, over twice as long as an uncorrected logical encoding, and 10% longer than the highest quality element of the system (the resonator's 0, 1 Fock states). Our results illustrate the power of novel, hardware efficient qubit encodings over traditional QEC schemes. Furthermore, they advance the field of experimental error correction from confirming the basic concepts to exploring the metrics that drive system performance and the challenges in implementing a fault-tolerant system

Facile Synthesis of Pyrazole- and Benzotriazole-Containing Selenoethers

Azole-containing selenoethers, 1,5-bis(3,5-dimethylpyrazol-1-yl)-3-selena pentane and 1,3-bis(1,2,3-benzotriazol-1-yl)-2-selena propane were prepared by the reaction of corresponding tosylate or chloride with sodium selenide generated in situ from elemental selenium and sodium formaldehydesulfoxylate (rongalite)

Confining the state of light to a quantum manifold by engineered two-photon loss

Physical systems usually exhibit quantum behavior, such as superpositions and entanglement, only when they are sufficiently decoupled from a lossy environment. Paradoxically, a specially engineered interaction with the environment can become a resource for the generation and protection of quantum states. This notion can be generalized to the confinement of a system into a manifold of quantum states, consisting of all coherent superpositions of multiple stable steady states. We have experimentally confined the state of a harmonic oscillator to the quantum manifold spanned by two coherent states of opposite phases. In particular, we have observed a Schrodinger cat state spontaneously squeeze out of vacuum, before decaying into a classical mixture. This was accomplished by designing a superconducting microwave resonator whose coupling to a cold bath is dominated by photon pair exchange. This experiment opens new avenues in the fields of nonlinear quantum optics and quantum information, where systems with multi-dimensional steady state manifolds can be used as error corrected logical qubits

Chronicles of nature calendar, a long-term and large-scale multitaxon database on phenology

We present an extensive, large-scale, long-term and multitaxon database on phenological and climatic variation, involving 506,186 observation dates acquired in 471 localities in Russian Federation, Ukraine, Uzbekistan, Belarus and Kyrgyzstan. The data cover the period 1890-2018, with 96% of the data being from 1960 onwards. The database is rich in plants, birds and climatic events, but also includes insects, amphibians, reptiles and fungi. The database includes multiple events per species, such as the onset days of leaf unfolding and leaf fall for plants, and the days for first spring and last autumn occurrences for birds. The data were acquired using standardized methods by permanent staff of national parks and nature reserves (87% of the data) and members of a phenological observation network (13% of the data). The database is valuable for exploring how species respond in their phenology to climate change. Large-scale analyses of spatial variation in phenological response can help to better predict the consequences of species and community responses to climate change.Peer reviewe

REVIEW ARTICLE The Role of N-Methyl-D-Aspartate (NMDA) Receptors in Pain: A Review

There is accumulating evidence to implicate the importance of N-methyl-d-aspartate (NMDA) receptors to the induction and maintenance of central sensitization during pain states. However, NMDA receptors may also mediate peripheral sensitization and visceral pain. NMDA receptors are composed of NR1, NR2 (A, B, C, and D), and NR3 (A and B) subunits, which determine the functional properties of native NMDA receptors. Among NMDA receptor subtypes, the NR2B subunitcontaining receptors appear particularly important for nociception, thus leading to the possibility that NR2Bselective antagonists may be useful in the treatment of chronic pain. (Anesth Analg 2003;97:1108–16) The mechanisms by which tissue injuries produce a state of pain represent one of the most intensely investigated areas in the biomedical sciences over several decades. A major advance in this field came in the late 1980s when two groups demonstrated that the spinal delivery of N-methyl-d-aspartate (NMDA) receptor (NMDAR) antagonists inhibits the hyperexcitability of spinal cord nociceptive neurons induced by C-fiber stimulation (1,2). Since then, hundreds of papers have been published emphasizing that activation of NMDARs after tissue injury and inflammation enables facilitated processing in the spinal cord. In this review, recent data on the role of NMDARs in pain will be examined in the context of subunit composition, particularly focusing on the importance of the NR2B subunit. The review introduces background information on receptor structure and functional properties. The contribution of peripheral somatic and visceral NMDARs to nociception is also discussed

Facile Synthesis of Pyrazole-and Benzotriazole-Containing Selenoethers

Azole-containing selenoethers, 1,5-bis(3,5-dimethylpyrazol-1-yl)-3-selena pentane and 1,3-bis(1,2,3-benzotriazol-1-yl)-2-selena propane were prepared by the reaction of corresponding tosylate or chloride with sodium selenide generated in situ from elemental selenium and sodium formaldehydesulfoxylate (rongalite)

Medium to severe iodine deficiency still exists in Abkhazia

Background.Due to historical reasons, Abkhazia is one of the few regions of the formerSoviet Unionwhere status of iodine nutrition of the population is still unknown and activities for the prevention of iodine deficiency are not carried out. Aim.To assess the status of iodine nutrtition of Abkhazian population (schoolchildren and pregnant women). Materials and methods.In total, 222 subjects were surveyed in Abkhazia, including 151 schoolchildren (age 812 years) and 61 pregnant women (aged 1939 years). The content of iodine has been studied in the urine, and the use of iodized salt has been assesses at the household level. Results.The results of the survey revealed medium to severe iodine deficiency in Abkhazia. In schoolchildren median urinary iodine concentration was 29.1 mcg/l, and in pregnant women 26.5 mcg/l. In some clusters the median urinary iodine concentration was below 20 mcg/l indicating the possibility of severe iodine deficiency. Conclusion.Results of the study point to a critical situation with regard to status of iodine nutrition of the population in Abkhazia. To eliminate iodine deficiency, based on experience of other Transcaucasian states (Armenia,Azerbaijan,Georgia), Abkhazia should take urgent measures to introduce partial or complete ban on the import, sale and use of common (non-iodized) salt

Synthesis and oxidation of some azole-containing thioethers

Pyrazole and benzotriazole-containing thioethers, namely 1,5-bis(3,5-dimethylpyrazol-1-yl)-3-thiapentane, 1,8-bis(3,5-dimethylpyrazol-1-yl)-3,6-dithiaoctane and 1,3-bis(1,2,3-benzotriazol-1-yl)-2-thiapropane were prepared and fully characterized. Oxidation of the pyrazole-containing thioether by hydrogen peroxide proceeds selectively to provide a sulfoxide or sulfone, depending on the amount of oxidant used. Oxidation of the benzotriazole derivative by hydrogen peroxide is not selective, and sulfoxide and sulfone form concurrently. Selenium dioxide-catalyzed oxidation of benzotriazole thioether by H2O2, however, proceeds selectively and yields sulfoxide only