The LAMOST Survey of Background Quasars in the Vicinity of the Andromeda and Triangulum Galaxies -- II. Results from the Commissioning Observations and the Pilot Surveys

We present new quasars discovered in the vicinity of the Andromeda and Triangulum galaxies with the LAMOST during the 2010 and 2011 observational seasons. Quasar candidates are selected based on the available SDSS, KPNO 4 m telescope, XSTPS optical, and WISE near infrared photometric data. We present 509 new quasars discovered in a stripe of ~135 sq. deg from M31 to M33 along the Giant Stellar Stream in the 2011 pilot survey datasets, and also 17 new quasars discovered in an area of ~100 sq. deg that covers the central region and the southeastern halo of M31 in the 2010 commissioning datasets. These 526 new quasars have i magnitudes ranging from 15.5 to 20.0, redshifts from 0.1 to 3.2. They represent a significant increase of the number of identified quasars in the vicinity of M31 and M33. There are now 26, 62 and 139 known quasars in this region of the sky with i magnitudes brighter than 17.0, 17.5 and 18.0 respectively, of which 5, 20 and 75 are newly-discovered. These bright quasars provide an invaluable collection with which to probe the kinematics and chemistry of the ISM/IGM in the Local Group of galaxies. A total of 93 quasars are now known with locations within 2.5 deg of M31, of which 73 are newly discovered. Tens of quasars are now known to be located behind the Giant Stellar Stream, and hundreds behind the extended halo and its associated substructures of M31. The much enlarged sample of known quasars in the vicinity of M31 and M33 can potentially be utilized to construct a perfect astrometric reference frame to measure the minute PMs of M31 and M33, along with the PMs of substructures associated with the Local Group of galaxies. Those PMs are some of the most fundamental properties of the Local Group.Comment: 26 pages, 6 figures, AJ accepte

Recent Progress in Binder‐Free Electrodes Synthesis for Electrochemical Energy Storage Application

Fabrication of binder-free electrodes is an effective way to increase the performance of electrochemical energy storage (EES) devices, such as rechargeable batteries and supercapacitors. In traditional electrodes, the binder is usually electrochemically inert and has weak interactions and interfaces between binder and the active material, which increase “dead mass” and directly affect the performance of energy storage system. The binder-free electrode can provide well-designed electrode material structure enables well connection between active materials themselves and current collectors. In addition, without insulating binder, electron and electrolyte ions can transfer more efficiently within the electrode materials. Here, we reviewed research efforts in using various techniques involving chemical, physical and electrical methods to fabricate binder-free electrodes. For every technique, we first briefly describe their principle and involved factors that influence the performance of as-fabricated binder-free electrodes and summarize advantages and disadvantages. Next, we reviewed several works which have used this technique to fabricate binder-free electrodes. Further, the effect of well-crafted structure design on the properties of energy storage performances including rate capability, and cycle stability was highlighted. Last, we offer our perspectives on the challenges and potential future research directions in this area. We hope this review can stimulate more research to design and synthesize the binder-free materials for EES devices

Prediction of 5‐year overall survival of diffuse large B‐cell lymphoma on the pola‐R‐CHP regimen based on 2‐year event‐free survival and progression‐free survival

Abstract This study aimed to predict the 5‐year overall survival (OS) benefit of pola‐R‐CHP versus R‐CHOP in the POLARIX trial based on the 2‐year event‐free survival (EFS) and progression‐free survival (PFS) rates in diffuse large B‐cell lymphoma (DLBCL). We identified randomized controlled trials (RCT) published before 31 May 2023. The correlation between the logarithmic (log) hazard ratio (HR) for EFS (HREFS) or PFS (HRPFS) and the HR for OS (HROS) was estimated at the trial‐level. Correlation analysis was performed between 2‐year PFS or EFS and 5‐year OS rates at the treatment arm‐level. Linear regression models were used to calculate the 5‐year OS of pola‐R‐CHP and R‐CHOP. In the included 20 RCTs, a linear correlation between HREFS (r = 0.765) or HRPFS (r = 0.534) and HROS was observed at the trial‐ level. Two‐year EFS (r = 0.918) or 2‐year PFS (r = 0.865) correlated linearly with 5‐year OS. Linear regression analysis between 2‐year EFS/PFS and 5‐year OS gave estimated 5‐year OS rates between pola‐R‐CHP and R‐CHOP of 6.4% and 6.3%, respectively. Two‐year EFS and PFS are feasible early endpoints in patients with DLBCL treated primarily with immunochemotherapy. The pola‐R‐CHP regimen is expected to improve 5‐year OS

Experimental and Theoretical Evidence of an Axially Chiral Borospherene

Chirality plays an important role in chemistry, biology, and materials science. The recent discovery of the B₄₀^–/0 borospherenes marks the onset of a class of boron-based nanostructures. Here we report the observation of axially chiral borospherene in the B₃₉^– nanocluster on the bases of photoelectron spectroscopy, global minimum searches, and electronic structure calculations. Extensive structural searches in combination with density functional and CCSD(T) calculations show that B₃₉^– has a <i>C</i>₃ cage global minimum with a close-lying <i>C</i>₂ cage isomer. Both the <i>C</i>₃ and <i>C</i>₂ B₃₉^– cages are chiral with degenerate enantiomers. The <i>C</i>₃ global minimum consists of three hexagons and three heptagons around the vertical <i>C</i>₃ axis. The <i>C</i>₂ isomer is built on two hexagons on the top and at the bottom of the cage with four heptagons around the waist. Both the <i>C</i>₃ and <i>C</i>₂ axially chiral isomers of B₃₉^– are present in the experiment and contribute to the observed photoelectron spectrum. The chiral borospherenes also exhibit three-dimensional aromaticity, featuring σ and π double delocalization for all valence electrons. Molecular dynamics simulations reveal that these chiral B₃₉^– cages are structurally fluxional above room temperature, compared to the highly robust <i>D</i>_2<i>d</i> B₄₀ borospherene. The current findings add chiral members to the borospherene family and indicate the structural diversity of boron-based nanomaterials