Large-field CO(1--0) observations toward the Galactic historical supernova remnants: a large cavity around Tycho's supernova remnant

The investigation of the interaction between the supernova remnants (SNRs) and interstellar gas is not only necessary to improve our knowledge of SNRs, but also to understand the nature of the progenitor systems. As a part of the Milky Way Imaging Scroll Painting CO line survey (MWISP), we study the interstellar gas surrounding the Galactic historical SNRs, using the PMO 13.7-meter telescope. In this work, we present large-field (3$^\circ$$\times$2$^\circ$) and high-sensitivity CO(1-0) molecular line observations toward Tycho's SNR. The CO observations reveal, from the outside in, large molecular clouds, stream-like structures, and an inner rim around Tycho's SNR. We derived the basic properties (column density, mass, and kinematics) of these objects based on the CO observations. The large molecular clouds individually show an arc toward the remnant center, outlining a large cavity with radii of $\sim$0.3$^\circ$$\times$0.6$^\circ$ (or 13 pc $\times$27 pc at a distance of 2.5 kpc) around the remnant. The CO line broadenings and asymmetries detected in the surrounding clouds, the observed expansion of the cavity, in concert with enhanced $^{12}$CO(2-1)/(1-0) intensity ratio detected in previous studies, suggest the interaction of the large cavity with a wind in the region. After excluding the scenario of a large bubble produced by bright massive stars, we suggest that the large cavity could be explained by accretion wind from the progenitor system of Tycho's supernova. Nevertheless, the possibility of the random distribution of a large cavity around Tycho's SNR cannot be ruled out thus far. Further observations are needed to confirm the physical association of the large cavity with Tycho's SNR.Comment: 15 pages, 9 figures, updated according to the A&A proo

Isolation and Identification of Acholeplasma sp. from the Mud Crab, Scylla serrata

For the first time, a mollicute-like organism (MLO) was cultured from moribund mud crabs (Scylla serrata) during an outbreak of clearwater disease in Zhejiang Province, China. The MLO displayed a fried-egg colony morphology in culture, did not possess a cell wall, and was not retained by 0.45 μm and 0.2 μm filters. It was able to ferment glucose, sucrose, lactose, and maltose, but it did not utilize arginine and urea. The MLO grew in the absence of bovine serum and was not susceptible to digitonin. Sequence analysis of the 16S rRNA gene revealed that this MLO had 99% identity with Acholeplasma laidlawii PG-8A, which indicates that the organism isolated from mud crabs is a member of the genus Acholeplasma

经尿道输尿管镜下微创治疗儿童输尿管术后再次狭窄 12例回顾分析

Objective: To explore the clinical efficacy of the minimally-invasive treatment of ureteral postoperative stenosis with self-made electrotome, ureteroscope hard expansion and ureteral stents indwelled. Methods: A retrospective analysis of 12 cases with ureteral postoperative strictures (10 in the upper, 1 in the middle, 1 in the lower ureters, 10 cases of male, female 2 cases, average 2.1 years) from June 2012 to April 2014 was made, the length from 0.2cm to 1.5 cm, with an average of 0.5 cm. Renal function were moderately impaired in 6 cases, severely impaired in 6 cases, underwent the therapy of ureteral stenosis with self-made micro-probe electrotome and ureteroscope hard expansion, postoperatively, one 4.7 or 6F ureteral stents were remained indwelling for 6～8 weeks. Results: 12 cases completed the operation smoothly, the operative duration was 35～65 minutes (average 46 minutes). No severe complications were accompanied. Postoperative hospital stays for 7～9 days, an average of 8.3 days. with a median follow-up 8 months (ranging form 1～20 months), success was achieved in 10 of the 12 children, 2 cases were unsuccessful so as to undergo pyeloureteroplasty on open surgery once again because of the long ureteral narrow（the length over 1.2cm）and recovered eventually. Conclusion: Minimally-invasive ureteroscopy combined with self-made electrotome ureteroscope hard expansion and ureteral stents indwelled is one of the effective methods for treatment of ureteral postoperative stenosis which worth further promotion clinical application, the operation effect is exact, little pain and quick recovery, it can be used to short period (<1.0cm) of ureteral stricture instead of long period (>1.2cm ) that requires to open surgery.目的  探讨输尿管镜下自制电刀电切、输尿管镜硬性扩张联合输尿管内支架置入治疗儿童输尿管术后再次狭窄的临床疗效。方法  回顾性分析2012年6月—2014年4月收治12例输尿管狭窄术后再次狭窄患者的临床资料，其中男10例，女2例；年龄6个月～9岁，平均2.1岁；肾盂输尿管连接处狭窄10例，输尿管中段狭窄1例，膀胱输尿管连接部狭窄1例；狭窄段长度0.2～1.5cm，平均0.5cm；患侧肾功能中度受损者6例，重度受损者6例。所有病例均经尿道输尿管镜下完成，双J管留置6～8周。结果  12例手术均顺利完成，手术时间35 65min，平均46min；术后住院时间7～9天，平均8.3天。12例患者均获随访，随访时间1～20个月，平均8个月。10例随访复查泌尿系彩超及MRU示肾积水明显减轻，IVU示输尿管显影通畅无明显狭窄；2例因长段狭窄段较长，拔除双J管后肾积水再次加重，再次行开放肾盂输尿管成形术，术后恢复好。结论  输尿管镜直视下电切狭窄区域、输尿管镜硬性扩张联合置入双J管治疗输尿管再次狭窄短段型（长度＜1.0cm）手术效果确切、痛苦小、术后恢复快，该方法对于长段型（长度＞1.2cm）效果不确切，建议开放手术

Subspecies in Przewalski's gazelle Procapra przewalskii and its conservation implication

Przewalski's gazelle Procapra przewalskii is an endangered species endemic to China. A question remains about subspecific variation in this species. Skulls of Przewalski's gazelle collected from its current remnant ranges around the Qinghai Lake in combi

The Online Data Quality Monitoring System at BESIII

The online Data Quality Monitoring (DQM) plays an important role in the data taking process of HEP experiments. BESIII DQM samples data from online data flow, reconstructs them with offline reconstruction software, and automatically analyzes the reconstructed data with user-defined algorithms. The DQM software is a scalable distributed system. The monitored results are gathered and displayed in various formats, which provides the shifter with current run information that can be used to find problems early. This paper gives an overview of DQM system at BESIII.Comment: Already submit to Chinese Physics

CO (J = 1–0) Observations toward Filamentary Molecular Clouds in the Galactic Region with l = [169.°75, 174.°75], b = [−0.°75, 0.°5]

We present observations of the CO isotopologues (12CO, 13CO, and C18O) toward the Galactic region with 169fdg75 ≤ l ≤ 174fdg75 and −0fdg75 ≤ b ≤ 0fdg5 using the Purple Mountain Observatory 13.7 m millimeter-wavelength telescope. Based on the 13CO (J = 1 − 0) data, we find five molecular clouds within the velocity range between −25 and 8 km s−1 that are all characterized by conspicuous filamentary structures. We have identified eight filaments with a length of 6.38–28.45 pc, a mean H2 column density of 0.70 × 1021–6.53 × 1021 cm−2, and a line mass of 20.24–161.91 M ☉ pc−1, assuming a distance of ~1.7 kpc. Gaussian fittings to the inner parts of the radial density profiles lead to a mean FWHM width of 1.13 ± 0.01 pc. The velocity structures of most filaments present continuous distributions with slight velocity gradients. We find that turbulence is the dominant internal pressure to support the fragmentation of filaments instead of thermal pressure. Most filaments have virial parameters smaller than 2; thus, they are gravitationally bound. Four filaments have an LTE line mass close to the virial line mass. We further extract dense clumps using the 13CO data and find that 64% of the clumps are associated with the filaments. According to the complementary IR data, most filaments have associated Class II young stellar objects. Class I objects are mainly found to be located in the filaments with a virial parameter close to 1. Within two virialized filaments, 12CO outflows have been detected, indicating ongoing star-forming activity therein.National Key Research & Development of China [2017YFA0402702]; European Unions Horizon 2020 research and innovation program [639459]; NSFC [11473069, 11503086, 11629302]This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]