Methane adsorption experiments over wide ranges of pressure (up to 30 MPa) and temperature (30–120 °C) were performed using a gravimetric method on the Longmaxi shale collected from the northeast ...boundary of Sichuan Basin, China. Organic geochemical analyses, shale composition determination, and porosity tests were also conducted. The experimental supercritical methane excess adsorption isotherms at different temperatures initially increase and then decrease with increasing pressure, giving a maximum excess adsorption capacity (G ex m = 1.86–2.87 cm3/g) at a certain pressure P m (6.71–12.90 MPa). The excess adsorption capacity decreases with increasing temperature below 28 MPa, while this effect reversed above 28 MPa. However, the absolute adsorption capacity decreases as the temperature increases over the full pressure range. Supercritical methane adsorption on shale is of temperature dependence because it is a physical exothermic process supported by calculated thermodynamic parameters. P m is positively correlated with the temperature, while the decline rates (0.021–0.058 cm3 g–1 MPa–1) in excess adsorption negatively correlate with the temperature. Meanwhile, Langmuir volume G L (3.07–4.04 cm3/g) decreases while Langmuir pressure P L (1.44–4.31 MPa) increases with temperature elevation. In comparison to the actual adsorbed gas (absolute adsorption), an underestimation exists in the excess adsorption calculation, which increases with increasing depth. The conventional method, without subtracting the volume occupied by adsorbed gas, overestimates the actual free gas content, especially for the deep shale reservoirs. In situ adsorbed gas is simultaneously controlled by the positive effect of the reservoir pressure and the adverse effect of the reservoir temperature. Nevertheless, in situ free gas is dominated by the positive effect of the reservoir pressure. Low-temperature overpressure reservoirs are favorable for shale gas enrichment. Geological application of gas-in-place estimation shows that, with increasing depth, the adsorbed gas content increases rapidly and then declines slowly, whereas the free gas content increases continuously. There was an equivalence point at which the contents of adsorbed and free gas are equal, and the equivalence point moved to the deep areas with increasing water saturation. Moreover, the adsorbed gas and free gas distribution are characterized by the dominant depth zones, providing the reference for shale gas exploration and development.
The tensile behaviors of an experimental nickel-base single crystal superalloy have been studied from room temperature to 1100 degree C. Obvious work hardening during the tensile tests from room ...temperature to 760 degree C has been observed. In contrast, at 900 degree C and 1000 degree C only a slight work hardening occurs. Furthermore, by using transmission electron microscopy (TEM), the microstructures of the alloy after tensile tests at various temperatures have been investigated. Detailed analysis demonstrates the stacking faults (SFs) presented in the gamma matrix at room temperature, 600 degree C and 760 degree C, which were seldom reported previously. These stacking faults are responsible for the appearance of stress jump (named steps) on the stress-strain curves. On the other hand, these stacking faults effectively prevent slipping of the dislocations and have a great contribution to work hardening. Apart from that, the stacking faults in gamma ' precipitates from room temperature to 900 degree C have also been observed. The interfacial dislocation networks at 1000 degree C and 1100 degree C cause a weak resistance to the slip dislocations because of the high flow stress. The a/3121 and a/2011 type dislocations are of vital importance for plastic deformation and rupture of the experimental alloy. At last, the relation between deformation mechanisms and tensile behaviors has been reasonably explained.
Background
According to some guidelines for the management of gastric cancer, adjuvant chemotherapy is recommended for patients with pT3–4 or node‐positive disease. The aim of this study was to ...define low‐ and high‐risk groups in terms of survival, and to predict the benefit of adjuvant fluoropyrimidine plus oxaliplatin (F‐OX) chemotherapy.
Methods
Patients with pT3–4 or node‐positive gastric cancer after gastrectomy with D2 lymphadenectomy between 2000 and 2013 were included. The performance of a previously published nomogram was assessed by discrimination and calibration. Patients were stratified into risk groups on the basis of the nomogram‐predicted overall survival probability. The efficacy of F‐OX within each risk subgroup was assessed using the log rank test and Cox regression analysis weighted by inverse propensity score.
Results
Some 1464 patients were included. The nomogram showed better discrimination than the seventh AJCC staging classification (concordance index 0·72 versus 0·68 respectively; P = 0·008) and accurate calibration. F‐OX was not associated with improved survival in patients in the low‐risk group, whereas it reduced the risk of death by over 20 per cent in the intermediate‐ and high‐risk groups (P = 0·036 and P < 0·001 respectively) (P for interaction = 0·014).
Conclusion
A nomogram can aid in individualized decision‐making regarding the administration of F‐OX after gastrectomy for cancer.
Facilitates individualized treatment
The promise of magnetic skyrmions in future spintronic devices hinges on their topologically enhanced stability and the ability to be manipulated by external fields. The technological advantages of ...nonvolatile zero-field skyrmion lattice (SkL) are significant if their stability and reliability can be demonstrated over a broad temperature range. Here, we study the relaxation dynamics including the evolution and lifetime of zero-field skyrmions generated from field cooling (FC) in an FeGe single-crystal plate via in situ Lorentz transmission electron microscopy (L-TEM). Three types of dynamic switching between zero-field skyrmions and stripes are identified and distinguished. Moreover, the generation and annihilation of these metastable skyrmions can be tailored during and after FC by varying the magnetic fields and the temperature. This dynamic relaxation behavior under the external fields provides a new understanding of zero-field skyrmions for their stability and reliability in spintronic applications and also raises new questions for theoretical models of skyrmion systems.
Individuals with impaired glucose tolerance (IGT) have a high risk of developing NIDDM. The purpose of this study was to determine whether, diet and exercise interventions in those with IGT may delay ...the development of NIDDM, i.e., reduce the incidence of NIDDM, and thereby reduce the overall incidence of diabetic complications, such as cardiovascular, renal, and retinal disease, and the excess mortality attributable to these complications. In 1986, 110,660 men and women from 33 health care clinics the city of Da Qing, China, were screened for IGT and NIDDM. Of these individual, 577 were classified (using World Health organization criteria) as having IGT. Subjects were randomized by clinic into a clinical trial, either to a control group or to one pf three active treatment groups diet only, exercise only or diet plus exercise. Follow-up evaluation examination were conducted at 2-year intervals over a year period to identify subjects who developed NIDDM. Cox's proportional hazard analysis was used to determine if the incidence of NIDDM varied by treatment assignment. The cumulative incidence of diabetes at 6 years was 67.7% (95% CI, 59.8-75.2) in the control group compared with 43.8% (95% CI, 35.5-52.3) in the diet group, 41.1% (95% CI, 33.4-49.4) in the exercise group, and 46.0% (95% CI, 37.3-54.7) in the diet-plus exercise group (P 0.05). When analyzed by clinic, each of the active intervention groups differed significantly from the control clinics (P 0.05). The relative decrease in rate of development of diabetes in the active treatment groups was similar when subjects were stratified as lean or overweight (BMI or greater than or equal to 25 kg/m2). In a proportional hazards analysis adjusted for differences in baseline BMI and fasting glucose, the diet, exercise, and diet-plus-exercise interventions were associated with 31% (P 0.03), 46% (P 0.0005), and 42% (P 0.005) reductions in risk of developing diabetes, respectively. Diet and/or exercise interve
We perform a comprehensive analysis of the strange-antistrange parton distribution function (PDF) asymmetry in the proton in the framework of chiral effective theory, including the full set of ...lowest-order kaon loop diagrams with off-shell and contact interactions, in addition to the usual on-shell contributions previously discussed in the literature. We identify the presence of δ-function contributions to the s¯ PDF at x=0, with a corresponding valencelike component of the s-quark PDF at larger x, which allows greater flexibility for the shape of s−s¯. Expanding the moments of the PDFs in terms of the pseudoscalar kaon mass, we compute the leading nonanalytic behavior of the number and momentum integrals of the s and s¯ distributions, consistent with the chiral symmetry of QCD. We discuss the implications of our results for the understanding of the NuTeV anomaly and for the phenomenology of strange-quark PDFs in global QCD analysis.
Because of the half-filled t_{2g}-electron configuration, the BO_{6} octahedral distortion in a 3d^{3} perovskite system is usually very limited. In this Letter, a perovskitelike oxide ...Hg_{0.75}Pb_{0.25}MnO_{3} (HPMO) with a 3d^{3} Mn^{4+} state was synthesized by using high pressure and high temperature methods. This compound exhibits an unusually large octahedral distortion enhanced by approximately 2 orders of magnitude compared with that observed in other 3d^{3} perovskite systems like RCr^{3+}O_{3} (R=rare earth). Essentially different from centrosymmetric HgMnO_{3} and PbMnO_{3}, the A-site doped HPMO presents a polar crystal structure with the space group Ama2 and a substantial spontaneous electric polarization (26.5 μC/cm^{2} in theory) arising from the off-center displacements of A- and B-site ions. More interestingly, a prominent net photocurrent and switchable photovoltaic effect with a sustainable photoresponse were observed in the current polycrystalline HPMO. This Letter provides an exceptional d^{3} material system which shows unusually large octahedral distortion and displacement-type ferroelectricity violating the "d^{0}-ness" rule.
This paper reports on ectoparasitic chigger mites found on small mammals in Yunnan Province, southwest China. Data were accumulated from 19 investigation sites (counties) between 2001 and 2009. A ...total of 10 222 small mammal hosts were captured and identified; these represented 62 species, 34 genera and 11 families in five orders. From the body surfaces of these 10 222 hosts, a total of 92 990 chigger mites were collected and identified microscopically. These represented 224 species, 22 genera and three subfamilies in the family Trombiculidae (Trombidiformes). Small mammals were commonly found to be infested by chigger mites and most host species harboured several species of mite. The species diversity of chigger mites in Yunnan was much higher than diversities reported previously in other provinces of China and in other countries. A single species of rodent, Eothenomys miletus (Rodentia: Cricetidae), carried 111 species of chigger mite, thus demonstrating the highest species diversity and heaviest mite infestation of all recorded hosts. This diversity is exceptional compared with that of other ectoparasites. Of the total 224 mite species, 21 species accounted for 82.2% of all mites counted. Two species acting as major vectors for scrub typhus (tsutsugamushi disease), Leptotrombidium scutellare and Leptotrombidium deliense, were identified as the dominant mite species in this sample. In addition to these two major vectors, 12 potential or suspected vector species were found. Most species of chigger mite had a wide range of hosts and low host specificity. For example, L. scutellare parasitized 30 species of host. The low host specificity of chigger mites may increase their probability of encountering humans, as well as their transmission of scrub typhus among different hosts. Hierarchical clustering analysis showed that similarities between different chigger mite communities on the 18 main species of small mammal host did not accord with the taxonomic affinity of the hosts. This suggests that the distribution of chigger mites may be strongly influenced by the environment in which hosts live.
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