150 research outputs found

    Liquid phase blockage in micro-nano capillary pores of tight condensate reservoirs

    Get PDF
    The development of tight condensate gas reservoirs faces complex formation damage mechanisms, seepage characteristics and hydrocarbon phase changes, which are common challenges for both tight gas reservoirs and condensate gas reservoirs. In the near-well area, the liquid phase blockage problem due to water phase retention formed by capillary spontaneous imbibition of invasive water and oil phase accumulation due to retrograde condensation precipitation has become a key obstacle to the efficient development of tight condensate gas reservoirs. Experiments were conducted to evaluate the damage of liquid phase blockage under different conditions near the wellbore area. The results show that when the liquid phase saturation in the near-wellbore area increased to 80.12%, the relative permeability of the gas phase decreased to 0. It is concluded that the mixed wettability of formation rocks, ultra-low water saturation, abundant hydrophilic clay minerals and high capillary resistance of micro-nano pores are the main causes for the easy adsorption and retention of liquid phase. Reduced pressure transmission capacity and irreversible formation damage induced by liquid-phase blockage are the two major controlling factors for the low liquid phase flowback rate. It is suggested that developing a flowback system based on the formation physical properties differentiation to control water phase invasion, and changing wettability or injecting thermochemical fluid to control condensate blocking are feasible methods to relieve liquid phase blockage damage in tight condensate reservoirs.Cited as: Wang, Y., Kang, Y., Wang, D., You, L., Chen, M., Yan, X. Liquid phase blockage in micro-nano capillary pores of tight condensate reservoirs. Capillarity, 2022, 5(1): 12-22. https://doi.org/10.46690/capi.2022.01.0

    A compact ka-band active integrated antenna with a GaAs amplifier in a ceramic package

    Get PDF
    This letter presents the design of a Ka-band active integrated antenna in package (AIAiP). A monolithic microwave integrated circuit amplifier based on the GaAs process and a compact patch antenna based on the printed circuit board process are implemented, respectively. Then, the amplifier and antenna are assembled together in a specified package using the wire-bond process. Thus, compared to the traditional solutions, the transmission loss and the size of the proposed AIAiP are significantly reduced. Furthermore, the influence of the bonding wire and the package is taken into account in the design of the amplifier and the antenna, respectively. A good agreement between the simulation and measurement results can be observed. The proposed AIAiP occupies a compact size of 7 × 7 mm2. Meanwhile, it achieves -10-dB impedance bandwidth from 33.4 to 37.2 GHz and a peak gain of 18.9 dBi at 35 GHz. Additionally, the impact of the package size on the antenna performance has been demonstrated for future AIA designers

    Real-world landscape transition of death causes in the immunotherapy era for metastatic non-small cell lung cancer

    Get PDF
    BackgroundWith approval of anti-PD-1/PD-L1, metastatic non-small cell lung cancer (NSCLC) has entered the era of immunotherapy. Since immune-related adverse events (irAEs) occur commonly in patients receiving anti-PD-1/PD-L1, the landscape of death causes may have changed in metastatic NSCLC. We aim to compare patterns of death causes in metastatic NSCLC between the pre-immunotherapy and immunotherapy era to identify the consequent landscape transition of death causes.MethodsIn this cohort study, 298,485 patients with metastatic NSCLC diagnosed between 2000 and 2018 were identified from the Surveillance, Epidemiology, and End Results Program. Unsupervised clustering with Bayesian inference method was performed for all patients’ death causes, which separated them into two death patterns: the pre-immunotherapy era group and the immunotherapy era group. Relative risk (RR) of each death cause between two groups was estimated using Poisson regression. Reduced death risk as survival time was calculated with locally weighted scatterplot smooth (Lowess) regression.ResultsTwo patterns of death causes were identified by unsupervised clustering for all patients. Thus, we separated them into two groups, the immunotherapy era (2015-2017, N=40,172) and the pre-immunotherapy era (2000-2011, N=166,321), in consideration of obscure availability to immunotherapy for patients diagnosed in 2012-2014, when the follow-up cutoff was set as three years. Although all-cause death risk had reduced (29.2%, 13.7% and 27.8% for death risks of lung cancer, non-cancer and other cancers), non-cancer deaths in the immunotherapy era (N=2,100, 5.2%; RR=1.155, 95%CI: 1.101-1.211, P<0.001) significantly increased than that in the pre-immunotherapy era (N=7,249, 5.0%), which included causes of chronic obstructive pulmonary disease, cerebrovascular disease, pneumonia and influenza, septicemia, infectious diseases, accidents and adverse effects, hypertension, and chronic liver disease and cirrhosis. However, cancer-caused deaths (excluding lung cancer) had no significant changes.ConclusionsThe real-world landscape of death causes has changed in metastatic NSCLC when entering the immunotherapy era, and the increased non-cancer diseases may contribute to the changes that may be associated with commonly occurring irAEs

    Analyzing evolution of variability in a software product line: from contexts and requirements to features

    Get PDF
    In the long run, features of a software product line (SPL) evolve with respect to changes in stakeholder requirements and system contexts. Neither domain engineering nor requirements engineering handles such co-evolution of requirements and contexts explicitly, making it especially hard to reason about the impact of co-changes in complex scenarios. In this paper, we propose a problem-oriented and value-based analysis method for variability evolution analysis. The method takes into account both kinds of changes (requirements and contexts) during the life of an evolving software product line. The proposed method extends the core requirements engineering ontology with the notions to represent variability-intensive problem decomposition and evolution. On the basis of problem-orientation, the analysis method identifies candidate changes, detects influenced features, and evaluates their contributions to the value of the SPL. The process of applying the analysis method is illustrated using a concrete case study of an evolving enterprise software system, which has confirmed that tracing back to requirements and contextual changes is an effective way to understand the evolution of variability in the software product line

    Exploration of potential novel drug targets and biomarkers for small cell lung cancer by plasma proteome screening

    Get PDF
    Background: Small cell lung cancer (SCLC) is characterized by extreme invasiveness and lethality. There have been very few developments in its diagnosis and treatment over the past decades. It is urgently needed to explore potential novel biomarkers and drug targets for SCLC.Methods: Two-sample Mendelian Randomization (MR) was performed to investigate causal associations between SCLC and plasma proteins using genome-wide association studies (GWAS) summary statistics of SCLC from Transdisciplinary Research Into Cancer of the Lung Consortium (nCase = 2,791 vs. nControl = 20,580), and was validated in another cohort (nCase = 2,664 vs. nControl = 21,444). 734 plasma proteins and their genetic instruments of cis-acting protein quantitative trait loci (pQTL) were used, whereas external plasma proteome data was retrieved from deCODE database. Bidirectional MR, Steiger filtering and phenotype scanning were applied to further verify the associations.Results: Seven significant (p < 6.81 × 10−5) plasma protein-SCLC pairs were identified by MR analysis, including ACP5 (OR = 0.76, 95% CI: 0.67–0.86), CPB2 (OR = 0.90, 95% CI: 0.86–0.95), GSTM3 (OR = 0.45, 95% CI: 0.33–0.63), SHMT1 (OR = 0.74, 95% CI: 0.64–0.86), CTSB (OR = 0.79, 95% CI: 0.71–0.88), NTNG1 (OR = 0.81, 95% CI: 0.74–0.90) and FAM171B (OR = 1.40, 95% CI: 1.21–1.62). The external validation confirmed that CPB2, GSTM3 and NTNG1 had protective effects against SCLC, while FAM171B increased SCLC risk. However, the reverse causality analysis revealed that SCLC caused significant changes in plasma levels of most of these proteins, including decreases of ACP5, CPB2, GSTM3 and NTNG1, and the increase of FAM171B.Conclusion: This integrative analysis firstly suggested the causal associations between SCLC and plasma proteins, and the identified several proteins may be promising novel drug targets or biomarkers for SCLC

    Improving feature location using structural similarity and iterative graph mapping

    Get PDF
    Locating program element(s) relevant to a particular feature is an important step in efficient maintenance of a software system. The existing feature location techniques analyze each feature independently and perform a one-time analysis after being provided an initial input. As a result, these techniques are sensitive to the quality of the input. In this paper, we propose to address the above issues in feature location using an iterative context-aware approach. The underlying intuition is that features are not independent of each other, and the structure of source code resembles the structure of features. The distinguishing characteristics of the proposed approach are: (1) it takes into account the structural similarity between a feature and a program element to determine feature-element relevance; (2) it employs an iterative process to propagate the relevance of the established mappings between a feature and a program element to the neighboring features and program elements. We evaluate our approach using two different systems, DirectBank, a small-scale industry financial system, and Linux kernel, a large-scale open-source operating system. Our evaluation suggests that the proposed approach is more robust and can significantly increase the recall of feature location with only a minor decrease of precision

    Optimization of Traced Neuron Skeleton Using Lasso-Based Model

    Get PDF
    Reconstruction of neuronal morphology from images involves mainly the extraction of neuronal skeleton points. It is an indispensable step in the quantitative analysis of neurons. Due to the complex morphology of neurons, many widely used tracing methods have difficulties in accurately acquiring skeleton points near branch points or in structures with tortuosity. Here, we propose two models to solve these problems. One is based on an L1-norm minimization model, which can better identify tortuous structure, namely, a local structure with large curvature skeleton points; the other detects an optimized branch point by considering the combination patterns of all neurites that link to this point. We combined these two models to achieve optimized skeleton detection for a neuron. We validate our models in various datasets including MOST and BigNeuron. In addition, we demonstrate that our method can optimize the traced skeletons from large-scale images. These characteristics of our approach indicate that it can reduce manual editing of traced skeletons and help to accelerate the accurate reconstruction of neuronal morphology

    Antibiotic susceptibility of Escherichia coli isolated from neonates admitted to neonatal intensive care units across China from 2015 to 2020

    Get PDF
    BackgroundEscherichia coli is one of the most common pathogens causing neonatal infections. Recently, the incidence and drug resistance of E. coli have increased, posing a major threat to neonatal health. The aim of this study was to describe and analyze the antibiotic resistance and multilocus sequence typing (MLST) characteristics of E. coli derived from infants admitted to neonatal intensive care units (NICUs) across China.MethodsIn this study, 370 strains of E. coli from neonates were collected. E. coli isolated from these specimens were subjected to antimicrobial susceptibility testing (by broth microdilution method) and MLST.ResultsThe overall resistance rate was 82.68%, with the highest rate of methicillin/sulfamethoxazole (55.68%) followed by cefotaxime (46.22%). Multiple resistance rate was 36.74%, 132 strains (35.68%) had extended-spectrum β-lactamase (ESBL) phenotype and 5 strains (1.35%) had insensitivity to the tested carbapenem antibiotics. The resistance of E. coli isolated from different pathogenicity and different sites of infections varied, strains derived from sputum were significantly more resistant to β-lactams and tetracyclines. Currently, the prevalence spectrum in NICUs was dominated by ST1193, ST95, ST73, ST69 and ST131 across China. And the multidrug resistance of ST410 was the most severe. ST410 had the highest resistance rate to cefotaxime (86.67%), and its most common multidrug resistance pattern was β-lactams + aminoglycosides + quinolones + tetracyclines + sulfonamides.ConclusionsSubstantial proportions of neonatal E. coli isolates were severely resistant to commonly administered antibiotics. MLST results can suggest the prevalent characteristics of antibiotic resistance in E. coli with different ST types

    Effect of Parental Migration on the Intellectual and Physical Development of Early School-Aged Children in Rural China

    Get PDF
    Abstract OBJECTIVE: The purpose of this study is to estimate the effect of parent migration on intellectual and physical development of early school-aged children in rural China. DESIGN: setting and participants: The present cross-sectional study participants were a subset from a controlled, cluster-randomized, double-blind trial. From October 2012 to September 2013, the offspring of women who participated in a large trial were examined in the present study. Wechsler intelligence scale for children (WISC-IV) in which validity and reliability were shown to be satisfactory was used to measure the intellectual function and trained anthropometrists measured weight and height of children using standard procedures. RESULTS: The mean difference of FSIQ scores between non-migration and both-parent migration groups was -3.68 (95%CI: -5.49, -1.87). After adjusting for the confounders, the mean difference of full-scale IQ between non-migration and both-parent migration group was -1.97 (95%CI: -3.92, -0.01), the mean differences of perceptual reasoning index and processing speed index were -2.41 (95%CI: -4.50, -0.31) and -2.39 (95%CI: -4.42, -0.35) between two groups respectively. CONCLUSION: Our results emphasized the impairment of both-parental migration in intellectual function (FSIQ, PRI, PSI) of children. These findings have important policy implications for the Chinese government to prevent the impairment of left-behind children. Further research is required to clarify the mechanisms by which both-parental migration influence the impairment in intellectual function of children

    Association of antenatal vitamin B complex supplementation with neonatal vitamin B12 status: evidence from a cluster randomized controlled trial

    Get PDF
    Purpose Evidence about the effect of maternal vitamin B12 supplementation on offspring’s vitamin B12 status is limited. The present interventional study sought to evaluate the association of antenatal vitamin B complex supplementation with neonatal vitamin B12 status. Methods In an ongoing cluster randomized controlled trial conducted in three rural counties in northwest China, pregnant women < 20 weeks of gestation were randomized to three treatment groups: blank control, iron supplements, or vitamin B complex supplements. All women were administered folic acid supplements during the periconceptional period. In a sub-study, we collected cord blood samples of 331 participants from the control or vitamin B complex groups in the Xunyi county from January 2017 to December 2017. Plasma concentrations of folate, vitamin B12, and homocysteine were measured. Linear mixed models with a random intercept for cluster were used to compare biochemical indexes between groups after controlling for covariates. Results Compared with newborns whose mothers were in the control group, newborns of the vitamin B complex-supplemented women had significantly higher cord plasma vitamin B12 (P = 0.001) and lower homocysteine concentrations (P = 0.043). The association of antenatal vitamin B complex supplementation with cord blood vitamin B12 concentrations appeared to be more pronounced among newborns with high folate status than those with low folate status (Pinteraction = 0.060). Conclusions Maternal vitamin B complex supplementation during pregnancy was associated with better neonatal vitamin B12 status in rural northwest China
    corecore