239 research outputs found
In Search of Infall Motion in Molecular Clumps. IV. Mapping of the Global Infall Sources
We have used the IRAM 30-m telescope to map some targets with HCO (1-0)
and HCO (1-0) lines in order to search for gas infall evidence in
the clumps. In this paper, we report the mapping results for 13 targets. All of
these targets show HCO emissions, while HCO emissions are
observed in ten of them. The HCO integrated intensity maps of ten targets
show clear clumpy structures, and nine targets show clumpy structures in the
HCO maps. Using the RADEX radiative transfer code, we estimate the
column density of HCO, and determine the abundance ratio
[HCO]/[H] to be approximately 10 to 10. Based on
the asymmetry of the HCO line profiles, we identify 11 targets show blue
profiles, while six clumps have global infall evidence. We use the RATRAN and
two-layer models to fit the HCO line profiles of these infall sources, and
analyze their spatial distribution of the infall velocity. The average infall
velocities estimated by these two models are 0.24 -- 1.85 km s and 0.28
-- 1.45 km s, respectively. The mass infall rate ranges from
approximately 10 to 10 M yr, which suggests that
intermediate- or high-mass stars may be forming in the target regions
In search for infalling clumps in molecular clouds -- A catalogue of CO blue-profiles
We have started a systematic survey of molecular clumps with infall motions
to study the very early phase of star formation. Our first step is to utilize
the data products by MWISP to make an unbiased survey for blue asymmetric line
profiles of CO isotopical molecules. Within a total area of 2400 square
degrees nearby the Galactic plane, we have found 3533 candidates showing
blue-profiles, in which 3329 are selected from the CO&CO pair and
204 are from the CO&CO pair. Exploration of the parametric spaces
suggests our samples are in the cold phase with relatively high column
densities ready for star formation. Analysis of the spatial distribution of our
samples suggests that they exist virtually in all major components of the
Galaxy. The vertical distribution suggest that the sources are located mainly
in the thick disk of 85 parsec, but still a small part are located far
beyond Galactic midplane. Our follow-up observation indicates that these
candidates are a good sample to start a search for infall motions, and to study
the condition of very early phase of star formation
Comparison of cold resistance physiological and biochemical features of four Herba Rhodiola seedlings under low temperature
AbstractTo discuss the cold resistance performance of different Herba Rhodiolae and successfully transplant Herba Rhodiolae to the Gansu plateau area for nursing, domestication and planting, this paper systematically studies six physiological and biochemical features of Rhodiola kirilowii, Rhodiola algida, Rhodiola crenulata and Herba Rhodiolae that are closely associated with cold resistance features and concludes with the cold resistance capability of Rhodiola kirilowii. In the selected six main indexes of the Herba Rhodiolae, the POD, SOD and CAT activity and MDA and Pro content in the leaf are the main physiological and biochemical indexes to indicate the cold resistance performance of four Herba Rhodiolae seedlings and can be regarded as the preliminary indexes to assess the winter performance of Herba Rhodiolae. The research work will provide the theoretical basis for the wild variants of Herba Rhodiolae and GAPJ base construction
First Principles Calculation and Analysis of Adsorption of Choline Deep with Zinc Oxide
This is an article in the field of metallurgical engineering. In order to better realize the leaching of zinc oxide from zinc-containing dust, Materials Studio software based on density functional theory was used to simulate and optimize the crystal structure of zinc oxide and the structure of three kinds of choline deep eutectic solvents, and the mutual adsorption model of the two was calculated. The calculated results show that the ZnO(001) plane is a complete cleavage plane, and the highest occupied state near the Fermi level shifts to the left, and the peak of the highest occupies state increases, and the p orbital of O and the d orbital of Zn are more active, which are the active sites of the ZnO(001) plane. Optimization of three choline hyper eutectic solvent shows that choline chloride forms multiple intermolecular hydrogen bonds with three different hydrogen bond donors centered on chlorine atom. The adsorption model of deep eutectic solvents and zinc oxide was calculated using Forcite module. The results shows that the interaction strength of zinc oxide with three choline deep eutectic solvent is Chcl-MA >Chcl-Urea>Chcl-Eg. The radial distribution function shows that malonic acid makes it easier for Cl in choline chloride to chemisorb with Zn. In the three kinds of hydrogen bond donors, the activity of oxygen atomic functional groups forming chemical bonds with Zn is C=O, N-O and C-O, indicating that C=O in malonic acid makes the combination of Chcl-MA and ZnO more stable. Results show that the leaching temperature of Chcl-MA is 70 ℃ and the liquid-solid ratio is 10∶1. Under the condition of leaching time of 1 h for 60 min, single mineral zinc oxide can be almost completely leached, and the leaching effect is far greater than that of Chcl-Urea and Chcl-Eg, thus proving the accuracy of molecular simulation and providing theoretical guidance for the leaching of zinc-containing dust in choline deep eutectic solvent
The prognostic value of circulating lymphocyte counts and ABO blood group in lung cancer stereotactic body radiation therapy: a retrospective study
Background: Clinically, there is a lack of simple and feasible indicators to predict the efficacy of stereotactic body radiation therapy (SBRT). Circulating lymphocyte counts (CLCs) is considered to be related to curative effect in conventional radiotherapy of lung cancer, and blood groups are also associated with the survival. In this study, we investigate the prognostic value of CLCs and ABO blood groups in lung cancer patients treated with SBRT.
Methods: We retrospectively analyzed 191 patients who were treated with lung cancer SBRT in Taizhou Hospital of Zhejiang Province from September 2014 to December 2018. The medical record system of Taizhou Hospital was used to collect relevant clinical data, such as stage, CLC, ABO blood groups and other important clinical co-variates. The effects of SBRT were evaluated by patient reexamination image data and telephone follow-up. The RECIST 1.1 standard was used to evaluate the short-term efficacy in the first, third, and sixth months after SBRT. Progression-free survival (PFS) was defined as the time from the day of SBRT to disease progression or death from any cause. Overall survival (OS) was measured from the day of SBRT until the last follow-up or death. Survival curves and univariate, multivariate logistic-regression analyses were used to expound the prognostic factors for local control (LC), PFS, and OS of lung cancer SBRT patients.
Results: Univariate and multivariate analysis results showed that post-SBRT CLCs were independent factors for the short-term efficacy 3 and 6 months after lung cancer SBRT [hazard ratio (HR) =0.249, P=0.037; HR =0.347, P=0.012]. Survival analyses showed that the PFS and OS of lung cancer SBRT patients with A blood type was significantly shorter than that in the other three non-A blood groups (PFS: 6.5 vs. 10 months, HR =1.535, P=0.020; OS: 24 vs. 41 months, HR =1.578, P=0.048). Moreover, the patients with high post-SBRT CLCs in the non-A blood group had the longest PFS and OS after lung cancer SBRT (HR =0.551, P=0.043).
Conclusions: Lung cancer SBRT patients with high-post-SBRT CLCs and non-A blood groups seem to exhibits best curative effect, which represent a potential opportunity to improve the clinical management of these patients. The mechanisms of this association deserve further verification and investigation
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