Search

Aims: To evaluate the ability of carbohydrate antigen 125 (CA125), human epididymis protein 4 (HE4), risk of ovarian malignancy algorithm (ROMA), and Copenhagen Index (CPH‐I) to identify primary ovarian cancer (OC) from borderline and benign ovarian tumors (OTs) and explore ideal cutoff points. Methods: A total of 684 OTs containing 276 OC patients, 116 ovarian borderline OTs and 292 benign OTs patients who underwent surgery in our hospital were included. We retrospectively searched the results of CA125 and HE4 before patients' surgery from the hospital's electronic medical records system. ROMA and CPH‐I were calculated according to their menopausal status and age, respectively. Diagnostic performance of these four were assessed by drawing receiver operating characteristic (ROC) curves. Results: CA125, HE4, ROMA, and CPH‐I were all significantly higher in OC women compared with borderline OTs (p < 0.001), followed by benign OTs (p < 0.001). Area under the curves (AUCs) for distinguishing OC were 0.850 (0.818–0.882), 0.891 (0.865–0.916), 0.910 (0.888–0.933) and 0.906 (0.882–0.930), respectively, and the corresponding ideal cutoff values for CA125, HE4, ROMA, and CPH‐I were 132.5, 68.6, 23.8, and 6.4, respectively. The difference between ROMA and CPH‐I was not significant (p = 0.97), but both were higher than CA125 and HE4 (p < 0.05). HE4 showed a significantly higher AUC than CA125 (p < 0.05). For postmenopausal women, CA125 performed equivalently to ROMA (p = 0.73) and CPH‐I (p = 0.91). Conclusions: In identifying patients with OC, ROMA and CPH‐I outperformed single tumor marker. The diagnostic performance of HE4 was significantly higher than that of CA125. CA125 was more suitable for postmenopausal women. [ABSTRACT FROM AUTHOR]

A rapid identification method for flue-cured tobacco quality was proposed based on Raman spectroscopy. Considering the critical quality factors of flue-cured tobacco-like oil content, softness, and glossiness, four statistical methods, random forest, K-nearest neighbor, logistic regression, and partial least squares, can effectively improve the accuracy of quality identification. We randomly collected 149 flue-cured tobacco samples from multiple producing areas in China. After Raman spectroscopy analysis, Savitzky–Golay convolution smoothing and multi-scatter correction were done. The functional groups were analyzed to select characteristic peaks as features for discriminant analysis. The results show that the Raman spectroscopic information can distinguish the quality of flue-cured tobacco with an accuracy greater than 95%, whereas the partial least-squares approach delivers an accuracy of 100%. We conclude that Raman spectroscopy can be considered a vital avenue for identifying the quality of flue-cured tobacco. [ABSTRACT FROM AUTHOR]

Introduction: Malaria importation can be caused by cross-border movement either of both people and anopheline mosquitoes. However, there still lacks robust evidence of imported malaria caused by Plasmodium spp. infected anopheles along international border areas (border-spill malaria). The objectives of this study were to confirm whether an outbreak of Plasmodium vivax malaria is border-spill malaria and assess the effects of China's public health response along China-Myanmar border. Methods: Epidemiological, parasitological and entomological investigations were conducted to investigate the outbreak of border-spill malaria. Meanwhile, comprehensive interventions were carried out to prevent further transmission and reintroduction of malaria. Results: Rapid diagnostic testing, microscopy and polymerase chain reaction were performed and the infections were confirmed as P. vivax. A total of 22 (9.21%) of 239 workers contracted P. vivax during the outbreak. Multivariate logistic regression analysis identified that the distance of worker shelters in China within 300 meters to the internally displaced person (IDP) camps in Myanmar was a risk factors associated with malaria infection (adjusted odds ratio 7.5920; 95% confidence interval, 2.6079–22.1013; P = 0.0002). After comprehensive interventions, malaria transmission was successfully interpreted and prevented at the project site till the completion of project on 14 January 2020, and recurrence of P. vivax malaria was not detected by the end of 2020. Conclusion: This study provided robust evidence of border-spill malaria along China-Myanmar border. Malaria parasite reservoir and distance travelled by female anopheline mosquitoes are two determinants for border-spill malaria. The public health response to the outbreak indicates that the malaria surveillance and response system works well in preventing reintroduction of malaria. However, prevention of border-spill malaria is still a major challenge in the Yunnan border area, China. [ABSTRACT FROM AUTHOR]

Re–Os radiometric dating of crude oil can be used to constrain the timing of hydrocarbon generation, migration or charge. This approach has been successfully applied to marine petroleum systems; however, this study reports on its application to lacustrine-sourced natural crude oils. Oil samples from multiple wells producing from the Cretaceous Nantun Formation in the Wuerxun-Beier depression of the Hailar Basin in NE China were analysed. Subsets of the Re–Os data are compatible with a Cretaceous hydrocarbon generation event (131.1 ± 8.4 Ma) occurring within 10 Myr of deposition of the Nantun Formation source rocks. In addition, two younger age trends of 54 ± 12 Ma and 1.28 ± 0.69 Ma can be regressed from the Re–Os data, which may reflect the timing of subsequent hydrocarbon generation events. The Re–Os geochronometer, when combined with complementary age dating techniques, can provide direct temporal constraints on the evolution of petroleum system in a terrestrial basin. [ABSTRACT FROM AUTHOR]

In order to choose the appropriate time for the dynamic reinforcement, the time effect of stress field evolution of the surrounding rock was first analyzed in this study. Then the deep soft rock roadway in Xinhu Coal Mine, China was taken as a typical example with regard to how the rheology-affected stress field of the surrounding rock evolved. The calculation algorithm of stress field evolution was given together with the corresponding program developed. Calculation results showed that the peak point of the surrounding rock in the early phase moved faster, where the turn appeared on the 60th day when the peak point lied 6.96 m away from the center of the roadway. Then the peak point moved at a slower pace, and finally, on the 124.8th day, the stress peak point was basically stabilized 7.21 m away from the center. In this way, the appropriate dynamically-reinforced supporting time of the No. 2 North rail-crosscut in Xinhu Mine was determined as 60 days after the primary support. In addition, a dynamic reinforcement technical plan was developed. The primary supporting system was bolt + W-shaped strip + diamond mesh + shallow hole grouting bolt + cable + shotcrete, and the reinforcement support system was bolt + M4 strip + diamond mesh + grouting cable. In-situ observation showed that both the maximum deformation and its maximum velocity in the roof and both walls of the roadway were small. The results indicated that both the reinforced supporting time and the parameters are appropriate. [ABSTRACT FROM AUTHOR]

The microbial community in oil reservoirs plays important roles in carbon, sulfur, and nitrogen cycling. We identified the microbial composition, abundance, and diversity in two heavy oil wells (W1 and W2) located at Liaohe oilfield, China, that were flooded with higher temperatures, forming a decreasing gradient-temperature field (DGTF) from the steam chamber to the original surrounding formation. The two wells were connected to each other at a depth of 650 m and with temperatures of 249 °C (W1) and 259 °C (W2) in the steam chamber. Water and oil samples were collected from both wells, and 16S rRNA genes were sequenced using Illumina MiSeq (Illumina, San Diego, CA). The number of operational taxonomic units (OTUs) was 5499 and 5938 for W1 and W2, respectively, at 97% clustering. In both wells, the dominant bacterial phylum was Proteobacteria. Euryarchaeota and Crenarchaeota were the only two archaeal phyla detected. Terrimonas and Fluviicola were more abundant in the water sample W1–W, whereas Thermomonas, Nitrosomonas, and Sphingobacterium were more abundant in the oil sample W2-O. Aquificae was the only phylum detected in these wells that had not been detected in other oilfields. Excluding exogenous contamination, the results of this study showed abundant in-situ microbial diversity. The heavy oil reservoir has a large DGTF in higher temperature heavy oil reservoirs, potentially affecting the inner environment. [ABSTRACT FROM AUTHOR]

Abstract: Detailed petrological, geochemical and geochronological studies were carried out for the core samples from the Chinese Continental Scientific Drilling Main Hole (CCSD-MH) with a final depth of 5158 m. This borehole has penetrated into an ultrahigh-pressure (UHP) metamorphic slice consisting mainly of eclogites, gneisses, garnet–pyroxenites and garnet–peridotites. Geochemical characteristics indicate that their protoliths are igneous rocks, and occur in a continental rifting tectonic setting. Quartz-, rutile- and ilmenite-rich eclogites from 0 to 710 m occur as alternating layers; the eclogites, together with interlayers of peridotites and gneisses form a layered ultramafic–mafic–acidic intrusion, which was formed by extensive fractional crystallization of basaltic magma in continental environments. The granitic gneisses from 1190 to 1505 m and 3460 to 5118 m show affinity to within-plate granite, whereas the granitic gneisses from 710 to 1190 m and 1505 to 3460 m exhibit characteristics of volcanic-arc granite. Zircon U–Pb dating demonstrates that the magmatic zircon cores, which have relatively high Th/U ratios (mostly >0.4), from both eclogites and gneisses, yield the same age at c. 788.8 Ma, suggesting that the protoliths of UHP rocks were formed by bimodal magmatism in Neoproterozoic rifting tectonic zones along the northern margin of the Yangtze Plate, in response to the breakup of the supercontinent Rodinia. U–Pb dating of metamorphic zircons with coesite and other eclogite-facies mineral inclusions and with relatively low Th/U ratios (mostly <0.14) gives similar Triassic ages, which define two main zircon-forming events at 221.1 Ma and 216.7 Ma. We suggest that the older weighted mean age represents the peak-UHP metamorphic event at a pressure of 5.0 GPa (corresponds to ∼165 km depth), whereas the younger mean age reflects the UHP/HP retrograde event at a pressure 2.8 GPa (∼92 km depth). Therefore, a maximum rate of vertical movement during early exhumation of the UHP rocks from the Sulu orogen would be 17 mm/year, which is quite similar to initial exhumation rates (16 to 35 mm/year) of many UHP terranes in the world. [Copyright &y& Elsevier]