136 research outputs found

    Evaluating Casing Damage Basing on Fuzzy Comprehensive Evaluation and Grey Relational Grade Analysis

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    Casing damage is one of the main factors influencing oil production, and determined the main factors which lead to casing damage is the premise to develop effective prevention and control measures of casing damage. The relationship between various factors of casing damage is complicated, and it is difficult to determine the main factors influenced the casing damage applying for conventional theoretical analysis and quantitative calculation. In this paper, the main factors influenced casing damage is evaluated by the method of combination fuzzy comprehensive evaluation and grey relational grade analysis. Firstly, this article analyzed factors causing casing damage, and then evaluated 22 wells of Daqing oilfield which is located in the west block of the Southern District fault. Comparing the evaluation and the actual results, the accuracy rate of this model is 86.3%, and showing that the evaluation results are accurate and reliable.Key words: Casing damage; Fuzzy comprehensive evaluation; Grey relational grade; Effect evaluatio

    The Research on the Model of the Multi-Interval Fracturing of Horizontal Wells

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    Multi-interval fracturing technology in horizontal well are used more and more widely in the exploitation of unconventional hydrocarbon resources, to accurately determine the initiation pressure having an important significance to improve the fracturing effect. On the basis of the homogeneous and isotropic two-dimensional plane strain model, established the geometric model of two-dimensional vertical fractures induced stress field; Based on rock mechanics and elastic mechanics theory, taking multi-stage fracturing induced stress into consideration, established the calculation model of the initiation pressure of the multi-stage fracturing of horizontal wells’ fracture. The calculation results showed that taking induced stress into consideration, the calculation result is consistent with the actual situation, compared with the actual construction pressure, and the average accuracy rate is 95.15%. It proved that this model can be used for calculating the initiation pressure of the multi-interval fracturing of horizontal wells’ fracture.Key words: Horizontal well; Multistage fracture; Initiation pressure; Induced stres

    Single-Port Laparoscopic Assisted Transcrotal Orchidopexy for Palpable Inguinal Canalicular Cryptorchidism Accompany With Indirect Inguinal Hernia

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    Purpose: To assess the outcomes of a novel laparoscopic assisted transcrotal orchidopexy (LATO) combined with percutaneous extraperitoneal closure (PEC) for palpable inguinal canalicular cryptorchidism accompany with indirect inguinal hernia, and evaluate its safety and efficiency.Materials and Methods: A retrospective cohort study for single-port LATO-PEC and traditional inguinal orchidopexy (TIO) was performed between 2011 and 2014. Totally 53 children with both palpable inguinal canalicular testes and indirect inguinal hernia were included. Median patient age was 15month (range, 6 months to 4 years). Of them, 35 patients underwent LATO-PEC procedure, utilizing an umbilical trocar for laparoscope, transcrotal dissection for orchidopexy, and an inner two-hooked cannula for ligation of the patent processus at the level of the internal ring. Three of them were bilateral, 12 on the left side and 20 on the right. Eighteen patients received TIO, seven of them on the left side and 11 on the right. Patient demographics, surgical technique, complications, and clinical outcomes were reviewed. Follow-up visits were performed to reassess position and size of the testes.Results: All 56 undescended testes were delivered into the scrotum successfully. In the LATO-PEC group, nine contralateral herniorrhaphy were accomplished simultaneously. Fifteen contralateral patent processus vaginalis (PPVs) in 32 unilateral undescended testis (UDT) were newly confirmed during the laparoscopy, while 6 of them received percutaneous extra-peritoneal herniorrhaphy for visible inguinal bubble in pneumoperitoneum condition. No additional port placement or conversion to open procedure was needed. Mean operative time for unilateral and bilateral LATO-PEC in this study was (37.81 ± 5.23) min and (53.33 ± 2.98) min, respectively. In TIO group, mean operative time was (41.11 ± 8.67) min. There was no statistical difference in operative time between the two approaches for unilateral UDTs (p = 0.098). Median follow-up interval was 24 months (range, 12–84 months). No operative complications were found in either group to date.Conclusions: Singe-port LATO-PEC is a safe, effective, and cosmetic choice for inguinal canalicular cryptorchidism accompany with indirect inguinal hernia, minimizing injuries to the vas deferens and testicular vessels. Laparoscopy can provide a diagnostic and therapeutic solution of contralateral PPV

    Identification and characterization of class 1 integrons among Pseudomonas aeruginosa isolates from patients in Zhenjiang, China

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    SummaryObjectivesThe role of integrons in the spread of antibiotic resistance has been well established. The aim of this study was to investigate the resistance profiles of Pseudomonas aeruginosa isolated from patients in Zhenjiang to 13 antibiotics, and to identify the structure and dissemination of class 1 integrons.MethodsThe Kirby–Bauer disk diffusion assay was used to determine the rate of P. aeruginosa resistance. Class 1 integrons from multidrug-resistant isolates were amplified by PCR, and their PCR products were sequenced. We also analyzed the integron structures containing the same gene cassettes by restriction fragment length polymorphism (RFLP). Isolates were genotyped by pulsed-field gel electrophoresis (PFGE).ResultsThe resistance rates were between 29.6% and 90.1%. The prevalence of class 1 integrons was 38.0%. These integrons included five gene cassettes (aadB, aac6-II, blaPSE-1, dfrA17, and aadA5). The dfrA17 and aadA5 gene cassettes were found most often.ConclusionsClass 1 integrons were found to be widespread in P. aeruginosa isolated from clinical samples in the Zhenjiang area of China. The antibiotic resistance rates in class 1 integron-positive strains of P. aeruginosa were noticeably higher than those in class 1 integron-negative strains. PFGE showed that particular clones were circulating among patients

    The Role of Circulating Tight Junction Proteins in Evaluating Blood Brain Barrier Disruption following Intracranial Hemorrhage

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    Brain injury after intracranial hemorrhage (ICH) results in significant morbidity and mortality. Blood brain barrier (BBB) disruption is a hallmark of ICH-induced brain injury; however, data mirroring BBB disruption in human ICH are scarce. The aim of this study was to assess the significance of circulating biomarkers in evaluating BBB disruption after ICH. Twenty-two patients with ICH were recruited in this study. Concentrations of the tight junction proteins (TJs) Claudin-5 (CLDN5), Occludin (OCLN), and zonula occludens 1 (ZO-1) and vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) were measured by using enzyme-linked immunosorbent assay in serum and cerebrospinal fluid (CSF) samples obtained from patients with ICH. The white blood cell (WBC) count in blood and CSF, albumin (ALB) levels in the CSF (ALB CSF ), and the BBB ratio were significantly higher in the ICH than in controls ( < 0.05). Significantly higher levels of CLDN5, OCLN, ZO-1, MMP-9, and VEGF in CSF were observed in the ICH group; these biomarkers were also positively associated with BBB ratio ( < 0.05). Our data revealed that circulating TJs could be considered the potential biomarkers reflecting the integrity of the BBB in ICH

    Saltwater intrusion into the Changjiang River : a model-guided mechanism study

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    Author Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 114 (2009): C02006, doi:10.1029/2008JC004831.The Changjiang River (CR) is divided into a southern branch (SB) and a northern branche (NB) by Chongming Island as the river enters the East China Sea. Observations reveal that during the dry season the saltwater in the inner shelf of the East China Sea flows into the CR through the NB and forms an isolated mass of saltwater in the upstream area of the SB. The physical mechanism causing this saltwater intrusion has been studied using the high-resolution unstructured-grid Finite-Volume Coastal Ocean Model (FVCOM). The results suggest that the intrusion is caused by a complex nonlinear interaction process in relation to the freshwater flux upstream, tidal currents, mixing, wind, and the salt distribution in the inner shelf of the East China Sea. The tidal rectification, resulting from the interaction of the convergence or divergence of tidal momentum flux and bottom friction over abrupt topography, produces a net upstreamward volume flux from NB to SB. With river discharge the net water transport in the NB is driven through a momentum balance of surface elevation gradient forcing, horizontal advection, and vertical diffusion. In the dry season, reducing the surface elevation gradient forcing makes tidal rectification a key process favorable for the saltwater intrusion. A northerly wind tends to enhance the saltwater intrusion by reducing the seaward surface elevation gradient forcing rather than either the baroclinic pressure gradient forcing or the wind-driven Ekman transport. A convergence experiment suggests that high grid resolution (∼100 m or less) is required to correctly resolve the net water transport through the NB, particularly in the narrow channel on the northern coast of Chongming Island.The development of FVCOM is supported by the Massachusetts Fisheries Institute through NOAA grants DOC/ NOAA/NA04NMF4720332 and DOC/NOAA/NA05NMF4721131; NSF grants OCE-0234545, OCE-0227679, OCE-0606928, OCE-0712903, OCE-0732084, OCE-0726851, ARC0712903; ARC0732084, and ARC0804029; NOAA grant NA160P2323; and an ONR subcontract grant from the Woods Hole Oceanographic Institution. The development of the nested modeling approach is supported by MIT and URI Sea Grant projects NA060AR41700019 and R/P-061. C. Chen serves as Zi Jiang Scholar at the State Key Laboratory for Estuarine and Coastal Research, East China Normal University (ECNU), and is an adjunct professor at Shanghai Ocean University (SHOU). His contribution is also supported by both ECNU and SHOU. P. Ding is supported by the Chinese National Key Basic Research Project grant 2002CB412403

    Ancient introgression drives adaptation to cooler and drier mountain habitats in a cypress species complex

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    Funding: This work was supported by the National Natural Science Foundation of China (grant numbers 31590821, 31622015, 31370261), the National Basic Research Program of China (grant number 2014CB954100), Sichuan Provincial Department of Science and Technology (grant number 2015JQ0018) and Sichuan University (Fundamental Research Funds for the Central Universities, SCU2019D013, SCU 2018D006)Introgression may act as an important source of new genetic variation to facilitate the adaptation of organisms to new environments, yet how introgression might enable tree species to adapt to higher latitudes and elevations remains unclear. Applying whole-transcriptome sequencing and population genetic analyses, we present an example of ancient introgression from a cypress species (Cupressus gigantea) that occurs at higher latitude and elevation on the Qinghai-Tibet Plateau into a related species (C. duclouxiana), which has likely aided the latter species to extend its range by colonizing cooler and drier mountain habitats during postglacial periods. We show that 16 introgressed candidate adaptive loci could have played pivotal roles in response to diverse stresses experienced in a high-elevation environment. Our findings provide new insights into the evolutionary history of Qinghai-Tibet Plateau plants and the importance of introgression in the adaptation of species to climate change.Publisher PDFPeer reviewe

    Pervasive hybridization during evolutionary radiation of Rhododendron subgenus Hymenanthes in mountains of southwest China

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    Radiations are especially important for generating species biodiversity in mountainous ecosystems. The contribution of hybridization to such radiations has rarely been examined. Here, we use extensive genomic data to test whether hybridization was involved in evolutionary radiation within Rhododendron subgenus Hymenanthes, whose members show strong geographic isolation in the mountains of southwest China. We sequenced genomes for 143 species of this subgenus and 93 species of four other subgenera, and found that Hymenanthes was monophyletic and radiated during the late Oligocene to middle Miocene. Widespread hybridization events were inferred within and between the identified clades and subclades. This suggests that hybridization occurred both early and late during diversification of subgenus Hymenanthes, although the extent to which hybridization, speciation through mixing-isolation-mixing or hybrid speciation, accelerated the diversification needs further exploration. Cycles of isolation and contact in such and other montane ecosystems may have together promoted species radiation through hybridization between diverging populations and species. Similar radiation processes may apply to other montane floras in this region and elsewhere

    Downregulation of Hlx

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    T-bet plays an important role in immunoregulation; it induces the differentiation of Th1 together with the homeobox transcription factor gene Hlx. Recent studies show that T-bet and Th1-associated factors are critical in regulating tumor development. However, the contributions of Hlx in the occurrence and development of cancer remain unknown. In this study, the Hlx, T-bet, Runx3, and IFN-γ were measured in PBMC from patients with gastric cancer and the correlation between Hlx and T-bet or IFN-γ was assessed. The expression levels of Hlx, T-bet, and IFN-γwere significantly decreased, and there was a positive correlation between Hlx and T-bet or IFN-γ. In addition, the Runx3 expression was also downregulated with the lower T-bet mRNA level. These results suggested that the decreased Hlx expression was closely associated with T-bet and Runx3 downregulations and may contribute to the development of gastric cancer

    Estimating the effect of urease inhibitor on rice yield based on NDVI at key growth stages

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    The effect of the urease inhibitor, N-(n-butyl) thiophosphoric triamide (NBPT) at a range of application rates on rice production was examined in a field experiment at Jinxian County, Jiangxi Province, China. The normalized difference vegetation index (NDVI) was measured at key growth stages in both early and late rice. The results showed that the grain yield increased significantly when urea was applied with NBPT, with the highest yield observed at 1.00% NBPT (wt/wt). NDVI differed with the growth stage of rice; it remained steady from the heading to the filling stage. Rice yield could be predicted from the NDVI taken at key rice growing stages, with R<sup>2</sup> ranging from 0.34 to 0.69 in early rice and 0.49 to 0.70 in late rice. The validation test showed that RMSE (t·hm<sup>-2</sup>) values were 0.77 and 0.87 in early and late rice, respectively. Therefore, it was feasible to estimate rice yield for different amounts of urease inhibitor using NDVI
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