An Inquiry into the Application and Preparation of Surfactant in Oil Field

As a commonly used chemical agent, surfactant is used to improve the efficiency of oil-and-gas exploitation. Since the conventional surfactant technology fails to meet the requirements of oil-and-gas resources exploitation currently, this paper deeply researches on the studies of cutting-edge technology of oil-and-gas exploitation, and learns the advanced experience from foreign countries. It aims to point out that the needs of China’s demand for oil-and-gas exploitation can be met with through technology innovation, preparation methods improvement and key technology mastery of surfactant in oil field

Catalase Enhances Viability of Human Chondrocytes in Culture by Reducing Reactive Oxygen Species and Counteracting Tumor Necrosis Factor-α-Induced Apoptosis

Background/Aims: Both physiologic remodeling and pathologic regeneration of cartilage tissue rely upon chondrocyte functions and are benefited from factors that promote viability and inhibit apoptosis of the cell, and associated mechanisms. High level of reactive oxygen species (ROS) and proinflammatory cytokines activate apoptosis signaling and initiate cell death, which can be attenuated by antioxidants. This study examined the effect of catalase (CAT) on ROS and tumor necrosis factor-α (TNF-α)-induced apoptosis in human C28/I2 chondrocytes cultured in monolayer. Methods: Chondrocytes were treated with diluted CAT in the presence or absence of TNF-α and compared to untreated cells. Levels of hydrogen peroxide (H2O2) and mitochondrial membrane potential (Δψm) were measured using fluorescent labeling, cell apoptosis was assayed by flow cytometry using Annexin V/propidium iodide (PI) staining, gene expression was detected by quantitative real time polymerase chain reaction (qRT-PCR) and the proteins were investigated by Western blotting. Results: CAT effectively reduced the intracellular ROS caused by the monolayer culture system, enhanced the Δψm depending on the presence of TNF-α and promoted morphological features at sub-cellular level. CAT also attenuated the TNF-α-upregulated expression of factors/mediators of extrinsic cell death cascade and apoptotic caspases, ultimately resulted in promoted cellular viability. Conclusion: The anti-apoptotic effect of CAT on chondrocytes via scavenging ROS and suppressing TNF-α-induced cell apoptosis by TNF/TNF receptor (TNFR) mediated death signaling pathway and potentiate CAT as a complementary agent beneficial to cartilage remodeling and regeneration in vivo, and cell-based therapies of cartilage repair demanding viable cells expanded ex vivo

Heterogeneous Nitrate Production Mechanisms in Intense Haze Events in the North China Plain

Abstract Studies of wintertime air quality in the North China Plain (NCP) show that particulate-nitrate pollution persists despite rapid reduction in NOx emissions. This intriguing NOx-nitrate relationship may originate from non-linear nitrate-formation chemistry, but it is unclear which feedback mechanisms dominate in NCP. In this study, we re-interpret the wintertime observations of 17O excess of nitrate (∆17O(NO3−)) in Beijing using the GEOS-Chem (GC) chemical transport model to estimate the importance of various nitrate-production pathways and how their contributions change with the intensity of haze events. We also analyze the relationships between other metrics of NOy chemistry and [PM2.5] in observations and model simulations. We find that the model on average has a negative bias of −0.9‰ and −3617O(NO3−) and [Ox,major] (≡ [O3] + [NO2] + [p-NO3−]), respectively, while overestimating the nitrogen oxidation ratio ([NO3−]/([NO3−] + [NO2])) by +0.12 in intense haze. The discrepancies become larger in more intense haze. We attribute the model biases to an overestimate of NO2-uptake on aerosols and an underestimate in wintertime O3 concentrations. Our findings highlight a need to address uncertainties related to heterogeneous chemistry of NO2 in air-quality models. The combined assessment of observations and model results suggest that N2O5 uptake in aerosols and clouds is the dominant nitrate-production pathway in wintertime Beijing, but its rate is limited by ozone under high-NOx-high-PM2.5 conditions. Nitrate production rates may continue to increase as long as [O3] increases despite reduction in [NOx], creating a negative feedback that reduces the effectiveness of air pollution mitigation

Response to Technostress from the Dual Systems Perspective: The Moderating Role of Constant Connectivity

Enterprise social media (ESM) has supported the constant connectivity routine in workplace. Existing studies have identified the negative effects of ESM use, such as technostress, but rarely have explored how constant connectivity moderates the relationships between stressors and responses, which can result in various outcomes. Grounded on technostress literature, this study aims to examine the effects of both techno-eustress and techno-distress processes in the context of ESM use and constant connectivity. Further, to better understand how to respond to technostress, we will examine the cognitive mechanism from the perspective of dual systems theory and also investigate the moderation role of constant connectivity. This study will collect survey data in two waves. This study attempts to contribute to technostress literature by identifying the mediation role of dual systems responding mechanisms in this process, and by elucidating the influence of ESM constant connectivity on individual performance

Response to technostress from the dual systems perspective: The moderating role of constant connectivity

Enterprise social media (ESM) has supported the constant connectivity routine in workplace. Existing studies have identified the negative effects of ESM use, such as technostress, but rarely have explored how constant connectivity moderates the relationships between stressors and responses, which can result in various outcomes. Grounded on technostress literature, this study aims to examine the effects of both techno-eustress and techno-distress processes in the context of ESM use and constant connectivity. Further, to better understand how to respond to technostress, we will examine the cognitive mechanism from the perspective of dual systems theory and also investigate the moderation role of constant connectivity. This study will collect survey data in two waves. This study attempts to contribute to technostress literature by identifying the mediation role of dual systems responding mechanisms in this process, and by elucidating the influence of ESM constant connectivity on individual performance

The Detection of Foodborne Pathogenic Bacteria in Seafood Using a Multiplex Polymerase Chain Reaction System

Multiplex polymerase chain reaction (PCR) assays are mainly used to simultaneously detect or identify multiple pathogenic microorganisms. To achieve high specificity for detecting foodborne pathogenic bacteria, specific primers need to be designed for the target strains. In this study, we designed and achieved a multiplex PCR system for detecting eight foodborne pathogenic bacteria using specific genes: toxS for Vibrio parahaemolyticus, virR for Listeria monocytogenes, recN for Cronobacter sakazakii, ipaH for Shigella flexneri, CarA for Pseudomonas putida, rfbE for Escherichia coli, vvhA for Vibrio vulnificus, and gyrB for Vibrio alginolyticus. The sensitivity of the single system in this study was found to be 20, 1.5, 15, 15, 13, 14, 17, and 1.8 pg for V. parahaemolyticus, L. monocytogenes, E. coli O157:H7, C. sakazakii, S. flexneri, P. putida, V. vulnificus, and V. alginolyticus, respectively. The minimum detection limit of the multiplex system reaches pg/μL detection level; in addition, the multiplex system exhibited good specificity and stability. Finally, the assays maintained good specificity and sensitivity of 104 CFU/mL for most of the samples and we used 176 samples of eight aquatic foods, which were artificially contaminated to simulate the detection of real samples. In conclusion, the multiplex PCR method is stable, specific, sensitive, and time-efficient. Moreover, the method is well suited for contamination detection in these eight aquatic foods and can rapidly detect pathogenic microorganisms

Investigating the Effects of Video-Based E-Word-of-Mouth on Consumers’ Purchase Intention: The Moderating Role of Involvement

Short videos have been increasingly prevalent around the globe and have become an important channel for users to share product and service information and for marketers to attract potential customers. However, rarely have studies empirically examined the impact of product review videos posted on short video platforms on consumers’ purchase intention. Grounded in the elaboration likelihood model, this study proposes a research model to investigate how the product review video features (i.e., video information quality, product information visualization, video emotion polarity, and video publisher credibility) influence consumers’ purchase intention. Moreover, the moderating role of involvement (i.e., product involvement and video involvement) in the above-mentioned relationships have also been examined in this new research context. We empirically validate the research model with survey data. It is interesting to find that product information visualization and video publisher credibility are significantly and positively related to purchase intention. Video involvement negatively moderates the relationship between video publisher credibility and purchase intention. Furthermore, video emotion polarity negatively moderates the relationship between product information visualization and purchase intention. Both theoretical and practical implications are discussed

Bismuth oxychloride hollow microspheres with high visible light photocatalytic activity

Hollow microspheres of two bismuth oxychlorides, BiOCl and BiOCl, were successfully synthesized using carbonaceous microsphere sacrificial templates. The phase evolution from BiOCl to BiOCl was easily realized by heating the former at 600 °C. With a uniform diameter of about 200 nm, an average shell thickness of 40 nm, and basic nanosheets o