Gas emissions in Planck cold dust clumps---A Survey of the J=1-0 Transitions of 12^{12}CO, 13^{13}CO, and C18^{18}O

A survey toward 674 Planck cold clumps of the Early Cold Core Catalogue (ECC) in the J=1-0 transitions of $^{12}$CO, $^{13}$CO and C$^{18}$O has been carried out using the PMO 13.7 m telescope. 673 clumps were detected with the $^{12}$CO and $^{13}$CO, and 68% of the samples have C$^{18}$O emission. Additional velocity components were also identified.A close consistency of the three line peak velocities was revealed for the first time. Kinematic distances are given out for all the velocity components and half of the clumps are located within 0.5 and 1.5 kpc. Excitation temperatures range from 4 to 27 K, slightly larger than those of $T_d$. Line width analysis shows that the majority of ECC clumps are low mass clumps. Column densities N$_{H_{2}}$ span from 10$^{20}$ to 4.5$\times10^{22}$ cm$^{-2}$ with an average value of (4.4$\pm$3.6)$\times10^{21}$ cm$^{-2}$. N$_{H_{2}}$ cumulative fraction distribution deviates from the lognormal distribution, which is attributed to optical depth. The average abundance ratio of the $^{13}$CO to C$^{18}$O in these clumps is 7.0$\pm$3.8, higher than the terrestrial value. Dust and gas are well coupled in 95% of the clumps. Blue profile, red profile and line asymmetry in total was found in less than 10% of the clumps, generally indicating star formation is not developed yet. Ten clumps were mapped. Twelve velocity components and 22 cores were obtained. Their morphologies include extended diffuse, dense isolated, cometary and filament, of which the last is the majority. 20 cores are starless.Only 7 cores seem to be in gravitationally bound state. Planck cold clumps are the most quiescent among the samples of weak-red IRAS, infrared dark clouds, UC H{\sc ii} region candidates, EGOs and methanol maser sources, suggesting that Planck cold clumps have expanded the horizon of cold Astronomy.Comment: Accepted to Ap

Detection of respiratory viral and bacterial pathogens causing pediatric community-acquired pneumonia in Beijing using real-time PCR

Objective: The aim of this study was to determine the etiology and prevalence of pediatric CAP in Beijing using a real-time polymerase chain reaction (PCR) technique. Methods: Between February 15, 2011 and January 18, 2012, 371 pediatric patients with CAP were enrolled at Beijing Children's Hospital. Sixteen respiratory viruses and two bacteria were detected from tracheal aspirate specimens using commercially available multiplex real-time reverse transcription PCR (RT-PCR) kits. Results: A single viral pathogen was detected in 35.3% of enrolled patients, multiple viruses in 11.6%, and virus/bacteria coinfection in 17.8%. In contrast, only 6.5% of patients had a single bacterial pathogen and 2.2% were infected with multiple bacteria. The etiological agent was unknown for 26.7% of patients. The most common viruses were respiratory syncytial virus (RSV) (43.9%), rhinovirus (14.8%), parainï¬uenza virus (9.4%), and adenovirus (8.6%). In patients under three years of age, RSV (44.6%), rhinovirus (12.8%), and Streptococcus pneumoniae (9.9%) were the most frequent pathogens. In children aged 3â7 years, S. pneumoniae (38.9%), RSV (30.6%), Haemophilus inï¬uenzae (19.4%), and adenovirus (19.4%) were most prevalent. Finally in children over seven years, RSV (47.3%), S. pneumoniae (41.9%), and rhinovirus (21.5%) infections were most frequent. Conclusions: Viral pathogens, specifically RSV, were responsible for the majority of CAP in pediatric patients. However, both S. pneumoniae and H. inï¬uenzae contributed as major causes of disease. Commercially available multiplexing real-time PCR allowed for rapid detection of the etiological agent. Keywords: Real-time reverse transcription polymerase chain reaction (RT-PCR), Respiratory virus, Community-acquired pneumoni

Rac1 is dispensable for oocyte maturation and female fertility in vivo

<div><p>Oocyte maturation, the important process to produce female haploid gamete, accompanies with polarity establishment and highly asymmetric cell division to emit minor polar body within little cytoplasm. Microfilaments play central roles in polarity establishment and asymmetric cell division. Several actin regulators like WASP protein family as well as small GTPases function in microfilament dynamics, involving the process. Rac1, one member of RhoGTPases, has been reported to regulate the polarity and asymmetric cell division in mouse oocytes in vitro. The physiological role of Rac1 in mouse oocyte remains unknown. By conditional knockout technology, we specifically deleted <i>Rac1</i> gene in mouse oocyte, and found that Rac1 deletion exerted little effect on mouse oocyte maturation including polarity establishment and asymmetric division, and the mutant mice showed normal fertility.</p></div

Protein Phosphatase 6 Protects Prophase I-Arrested Oocytes by Safeguarding Genomic Integrity.

Mammalian oocytes are arrested at prophase of the first meiotic division in the primordial follicle pool for months, even years, after birth depending on species, and only a limited number of oocytes resume meiosis, complete maturation, and ovulate with each reproductive cycle. We recently reported that protein phosphatase 6 (PP6), a member of the PP2A-like subfamily, which accounts for cellular serine/threonine phosphatase activity, functions in completing the second meiosis. Here, we generated mutant mice with a specific deletion of Ppp6c in oocytes from the primordial follicle stage by crossing Ppp6cF/F mice with Gdf9-Cre mice and found that Ppp6cF/F; GCre+ mice are infertile. Depletion of PP6c caused folliculogenesis defects and germ cell loss independent of the traditional AKT/mTOR pathway, but due to persistent phosphorylation of H2AX (a marker of double strand breaks), increased susceptibility to DNA damage and defective DNA repair, which led to massive oocyte elimination and eventually premature ovarian failure (POF). Our findings uncover an important role for PP6 as an indispensable guardian of genomic integrity of the lengthy prophase I oocyte arrest, maintenance of primordial follicle pool, and thus female fertility

Influence of vacuum annealing temperature on the structure and properties of AlCrSiN/Mo self-lubricating coatings

The AlCrSiN/Mo self-lubricating coating was prepared by hybrid technology of high power impulse magnetron sputtering and pulsed DC magnetron sputtering, and the structure and properties were modified by vacuum annealing. The influence of vacuum annealing temperature on composition, microstructure, mechanical and tribological properties of AlCrSiN/Mo coatings was systematically investigated by scanning electron microscope, X-ray diffractometer, electron probe analyzer, nano-indentation tester, scratch tester and friction and wear tester. The results show that all the AlCrSiN/Mo coatings possess the nanocomposite structure, namely the nc-(Al,Cr,Mo)N is surrounded by a-Si3N4 amorphous phase. After vacuum annealing, the particle size on the coating surface is increased significantly, whereas the nanohardness and critical load of the coatings are decreased correspondingly, and the wear resistance and antifriction performance are improved significantly. After being annealed at a temperature of 700 ℃, the coating presents the optimum properties with a nanohardness of 18.3 GPa, a friction coefficient of 0.51 and a wear rate of 3.4×10-4 μm3·(N·μm)-1. In this case, the characteristic values of H/E and H3/E*2 keep the highest

<i>Rac1</i> deletion has no effect on oocyte maturation.

<p>For A and B, chromosomes were stained in blue by Hoechst 33342 (2ng/mL in M16 medium) and the blue was changed into red. Alexa 488-phalloidin was microinjected into GV oocytes to show the actin dynamics during oocyte maturation. Bar = 20 μM. (A) The dynamics of Alexa 488-phalloidin during <i>Rac1</i>^{<i>loxP/loxP</i>} oocyte maturation. (B) The dynamics of Alexa 488- phalloidin during <i>Rac1</i>^{<i>loxP/loxP</i>}; <i>ZCre</i>^<i>+</i> maturation. (C) Normal actin cap in <i>rac1</i>^{<i>loxP/loxP</i>}; <i>ZCre</i>^<i>+</i> MII eggs. Oocytes were stained Alexa 488-phalloidine (green) and PI (10μg/mL, red), and viewed with confocal microscopy. Bar = 20μM.</p

Knockdown of Rac3 has no effect on <i>Rac1</i>^{<i>loxP/loxP</i>}; <i>ZCre</i>^<i>+</i> oocyte maturation.

<p>(A) Knockdown of Rac3 through RNA interference in <i>Rac1</i>^{<i>loxP/loxP</i>}; <i>ZCre</i>^<i>+</i> oocytes. The <i>Rac1</i>^{<i>loxP/loxP</i>}; <i>ZCre</i>^<i>+</i> oocytes were microinjected control SiRNA or Rac3 SiRNA, incubated in M16 medium with 2.5μM Milrinone for 24 hours, and then were collected for qRT-PCR. The experiments were repeated at least three times. ** P<0.01. (B) Normal MII eggs matured from Rac3-knockdowned- <i>Rac1</i>^{<i>loxP/loxP</i>}; <i>ZCre</i>^<i>+</i> oocytes. The control SiRNA or Rac3 SiRNA was microinjected into <i>Rac1</i>^{<i>loxP/loxP</i>}; <i>ZCre</i>^<i>+</i> oocytes. The oocytes were incubated in M16 medium with 2.5μM Milrinone for 24 hours, then were cultured in M16 medium, and the MII eggs were collected for immunofluorescent staining. The experiments were repeated for three times, and the typical images were shown. Green, spindle; Red,chromosomes.Bar,50μM.</p

Normal fertility and MII eggs in female mice with oocyte-specific deletion of <i>Rac1</i>.

<p>(A) Comparison of the average number of pups per litter per female mice during a period of 6 months between <i>Rac1</i>^{<i>loxP/loxP</i>}; <i>ZCre</i>^<i>+</i> (n = 4) and <i>Rac1</i>^{<i>loxP/loxP</i>} mice (n = 3). P>0.05. The data are mean ± SEM. (B) Normal spindle/chromosomes in <i>Rac1</i>^{<i>loxP/loxP</i>}; <i>ZCre</i>^<i>+</i> MII eggs. Ovulated eggss were fixed and stained with anti-α-tubulin- FITC antibody (green) and counterstained with PI to visualize DNA (red). Experiments were repeated at least three times and representative images were shown.</p