Evolution of pore structure, submaceral composition and produced gases of two Chinese coals during thermal treatment

This research was funded by the Research Program for Excellent Doctoral Dissertation Supervisor of Beijing (grant no. YB20101141501), the Fundamental Research Funds for Central Universities (grant no. 35832015136) and Key Project of Coal-based Science and Technology in Shanxi Province-CBM accumulation model and reservoir evaluation in Shanxi province (grant no. MQ2014-01).Peer reviewedPostprin

Does global value chain engagement improve export quality? Evidence from Chinese manufacturing firms

Using a firm-level data set of Chinese manufacturing sector, we examine whether global value chain (G.V.C.) engagement induces firms to upgrade the quality of the goods that they export. Empirical results show that G.V.C. participation has positive impact on export product quality, and this finding is consistent across several robustness checks. However, the influence of G.V.C. embedment on export quality presents an ‘inverted-U’ shape. The mechanism analysis demonstrates that the effect of G.V.C. participation on export quality is driven by competition effect and firms’ willingness to import high-quality intermediates. Furthermore, the quality effect of G.V.C. embedment differs depending on firm characteristics. This article therefore contributes to a better understanding of the benefits of participation in G.V.C.s for manufacturing firms from developing countries

1,1′-(4-Oxoheptane-1,7-di­yl)bis­(2-methyl-1H-benzimidazole) penta­hydrate

The title compound, C23H26N4O·5H2O, has noncrystallographic twofold rotation symmetry in the solid state. It crystallizes with five solvent water mol­ecules in the asymmetric unit. Four of these water mol­ecules are connected with each other via hydrogen-bonding inter­actions to form two types of centrosymmetric hexa­meric (H2O)6 rings. Via edge sharing of the hexa­mers, the water clusters thus build infinite chains that stretch parallel to the a axis. The fifth water mol­ecule provides an additional connection between the two hexa­meric (H2O)6 units via hydrogen bonds to both rings. The water mol­ecules in the channels along the a axis are also bonded via O—H⋯N hydrogen bonds to the organic units, and face-to-face π–π inter­actions [with centroid-to-centroid distances of 3.656 (1) Å and average face-to-face distances of 3.431 (5) Å] between the aromatic rings of adjacent mol­ecules complete the inter­molecular inter­actions in this structure

Analysis of CKM-Favored Quasi-Two-Body B→D(R→)KπB \to D (R\to) K \pi Decays in PQCD Approach

LHCb Collaboration studied the resonant structure of $B_s\to \overline{D}^0K^-\pi^+$ decays using the Dalitz plot analysis technique, based on a data sample corresponding to an integrated luminosity of $3.0{\rm fb}^{-1}$ of $pp$ collision. The $K^-\pi^+$ components have been analyzed in the amplitude model, where the decay amplitude is modeled to be the resonant contributions with respect to the intermediate resonances $K^*(892)$, $K_0^*(1430)$ and $K_2^*(1430)$. Motivated by the experimental results, we investigate the color-favored quasi-two-body $B \to \overline{D}^0K\pi$ decays in the framework of the perturbative QCD (PQCD) approach. We calculate the the branching fractions by introducing the appropriate wave functions of $K\pi$ pair. Our results are in agreement well the available data, and others can be tested in LHCb and Belle-II experiments. Using the narrow-width-approximation, we also extract the branching fractions of the corresponding two-body $B\to \overline D R$ decays, which agree to the previous theoretical calculations and the experimental data within the errors. There are no $CP$ asymmetries in these decays in the standard model, because these decays are all governed by only the tree operators.Comment: 18 pages, 1 figure

Surgical treatment of multivalvular endocarditis: Twenty-one–year single center experience

ObjectiveLittle information is available about surgical outcomes in patients with multivalvular endocarditis. The aim of this article is to review the 21-year experience with surgical treatment of patients with multivalvular endocarditis at our institution and, in particular, to determine the incidence, pathologic status, diagnosis, surgical strategies, and outcomes of patients with this disease.MethodsFrom January 1986 to December 2006, a total of 48 patients (40 men, 8 women), with a mean age of 42 ± 12 years, underwent surgery for multivalvular endocarditis. Endocarditis was active in 32 patients and healed in 16. Preoperative transthoracic echocardiographic evaluation was performed in all 48 patients with addition of transesophageal echocardiography in 22 (45.8%). Intraoperative findings showed that the endocarditis involved mostly the mitral and aortic valves (40/48 patients). Triple or quadruple valve involvement was found in 1 and 2 patients, respectively. Preoperative, perioperative, and postoperative data were retrospectively analyzed and risk factors for early and late survival were determined.ResultsIn only 24 (50.0%) patients was multivalvular endocarditis diagnosed by preoperative transthoracic echocardiography; 17 (77.3%) patients had multivalvular endocarditis confirmed by preoperative transesophageal echocardiography. The 30-day hospital mortality was 12.5% (n = 6). Preoperative renal failure, New York Heart Association class IV, and emergency surgery were identified as independent risk factors for hospital mortality. Overall long-term survival was 74% ± 6% at 5 years and 62% ± 3% at 10 years. Multivariate analysis revealed that renal failure and recurrent endocarditis were associated with increased late mortality. Ten-year freedom from recurrent endocarditis was 74% ± 5% and 10-year freedom from reoperation was 73% ± 6%.ConclusionsIn our institution, multivalvular endocarditis was diagnosed by transthoracic echocardiography in only half of the patients. Intraoperative transesophageal echocardiography provided a more effective means to identify this disease. Radical resection of all infected tissues for patients with multivalvular endocarditis and additional intraoperative interventions, depending on the intraoperative pathologic condition, produced satisfactory in-hospital and long-term results, similar to those in patients with a single infected heart valve

Factors affecting reorientation of hydraulically induced fracture during fracturing with oriented perforations in shale gas reservoirs

Hydraulic fracturing with oriented perforations is an effective technology for reservoir stimulation for gas development in shale reservoirs. However, fracture reorientation during fracturing operation can affect the fracture conductivity and hinder the effective production of shale gas. In the present work, a numerical simulation model for investigating fracture reorientation during fracturing with oriented perforations was established, and it was verified to be suitable for all investigations in this paper. Based on this, factors (such as injection rate and fluid viscosity) affecting both of initiation and reorientation of the hydraulically induced fractures were investigated. The investigation results show that the fluid viscosity has little effect on initiation pressure of hydraulically induced fracture during fracturing operation, and the initiation pressure is mainly affected by perforation azimuth, injection rate and the stress difference. Moreover, the investigation results also show that perforation azimuth and difference between two horizontal principle stresses are the two most important factors affecting fracture reorientation. Based on the investigation results, the optimization of fracturing design can be achieved by adjusting some controllable factors. However, the regret is that the research object herein is a single fracture, and the interaction between fractures during fracturing operation needs to be further explored

Relationship between the expression of hTERT and EYA4 mRNA in peripheral blood mononuclear cells with the progressive stages of carcinogenesis of the esophagus

<p>Abstract</p> <p>Objective</p> <p>To establish a relationship between esophageal squamous cell diseases and the expression of human telomerase reverse transcriptase (hTERT) and Eyes absent 4 (EYA4) mRNA in peripheral blood mononuclear cells.</p> <p>Methods</p> <p>Subjects were 50 patients with esophageal squamous cell carcinoma (ESCC), 50 with dysplasia (ESCD), 50 with basal cell hyperplasia (BCH) and 50 controls. All subjects were residents of Feicheng County, Shandong Province, China , diagnosed by histopathology. Expression of hTERT and EYA4 mRNA in peripheral blood was determined by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR).</p> <p>Results</p> <p>The hTERT and EYA4 mRNA positive expression increased according to disease severity. At the cut-off value of ≥ 0.2, the positive expression rates of EYA4 were 14% for controls, 20.0% for BCH, 26% for ESCD and 52% for ESCC, respectively. At the cut-off value of ≥ 0.8, the positive expression rates of hTERT in the four groups were 24%, 30.0%, 52% and 80%, respectively. Using a positive value of 0.47 for EYA4, the testing sensitivities in the ESCD and ESCC groups were 4% and 16%, respectively, and the testing specificity increased to 100%. Using a positive value of 1.0 for hTERT, the testing sensitivities in the ESCD and ESCC groups were 48% and 60%, respectively, and the testing specificity increased to 72%. The testing sensitivities in the predicting ESCD and ESCC in the discriminant model including EYA4 and hTERT and the five traditional risk factors (sex, age, smoking, alcohol drinking, and family history of esophageal cancer) were 70% and 80%, and testing specificities were 76% and 88% respectively. However, the testing sensitivities and specificities in the predicting ESCD and ESCC in the model only including the above five traditional risk factors were lower than that in the former case.</p> <p>Conclusion</p> <p>EYA4 and hTERT mRNA expression increased with the severity of esophageal pathological changes and may be useful for identifying high-risk endoscopy candidates or for monitoring changes in premalignant esophageal lesions.</p

Optimization of Fermentation Medium for the Production of Atrazine Degrading Strain Acinetobacter

Statistical experimental designs provided by statistical analysis system (SAS) software were applied to optimize the fermentation medium composition for the production of atrazine-degrading Acinetobacter sp. DNS32 in shake-flask cultures. A “Plackett-Burman Design” was employed to evaluate the effects of different components in the medium. The concentrations of corn flour, soybean flour, and K2HPO4 were found to significantly influence Acinetobacter sp. DNS32 production. The steepest ascent method was employed to determine the optimal regions of these three significant factors. Then, these three factors were optimized using central composite design of “response surface methodology.” The optimized fermentation medium composition was composed as follows (g/L): corn flour 39.49, soybean flour 25.64, CaCO3 3, K2HPO4 3.27, MgSO4 ·7H2O 0.2, and NaCl 0.2. The predicted and verifiable values in the medium with optimized concentration of components in shake flasks experiments were 7.079×108 CFU/mL and 7.194×108 CFU/mL, respectively. The validated model can precisely predict the growth of atrazine-degraing bacterium, Acinetobacter sp. DNS32