Experimental Study of Fracture Propagation Mechanisms by Oriented Perforation Technology for SRV Fracturing

 Due to the growing importance of shale oil and gas resources, more effective techniques to develop unconventional reservoirs are strongly required. In this paper, a new volumetric fracturing measure for unconventional resources based on oriented perforation technology has been introduced. Moreover, this innovative approach was validated through a series of laboratory experiments varying the parameters of physical models, such as perforation azimuth, perforation length and horizontal stress difference. The results showed that the artificial hydraulic fracture formed by using oriented perforation technology was not a satisfactory straight dual-wing fracture, instead, it was a bent dual-wing crack like “S” or “X”, which could significantly increase the stimulated reservoir volume. The perforation azimuth and horizontal stress difference were the primary factors that affected the formation of multi fractures. The reorientation path was extended with the increasing of the oriented perforation azimuth angle, but decreased with the increasing of horizontal stress difference. In addition, increasing the perforation length could greatly decrease the initiation pressure. Therefore, the oriented perforation technology could be as a powerful way to accelerate the exploitation of the unconventional reservoirs. Due to the growing importance of shale oil and gas resources, more effective techniques to develop unconventional reservoirs are strongly required. In this paper, a new volumetric fracturing measure for unconventional resources based on oriented perforation technology has been introduced. Moreover, this innovative approach was validated through a series of laboratory experiments varying the parameters of physical models, such as perforation azimuth, perforation length and horizontal stress difference. The results showed that the artificial hydraulic fracture formed by using oriented perforation technology was not a satisfactory straight dual-wing fracture, instead, it was a bent dual-wing crack like “S” or “X”, which could significantly increase the stimulated reservoir volume. The perforation azimuth and horizontal stress difference were the primary factors that affected the formation of multi fractures. The reorientation path was extended with the increasing of the oriented perforation azimuth angle, but decreased with the increasing of horizontal stress difference. In addition, increasing the perforation length could greatly decrease the initiation pressure. Therefore, the oriented perforation technology could be as a powerful way to accelerate the exploitation of the unconventional reservoirs

Effect of Lipopolysaccharide (LPS) and Outer Membrane Protein (OMP) Vaccines on Protection of Grass Carp (Ctenopharyngodon idella) against Aeromonas hydrophila

Abstract The gram-negative bacterium, Aeromonas hydrophila, causes high mortality and economic losses to the aquaculture industry. We investigated whether lipopolysaccharide (LPS) or outer membrane proteins (OMP) from A. hydrophila can enhance specific and/or non-specific immunity in grass carp (Ctenopharyngodon idella). Fish were injected intraperitoneally with LPS, OMP, or formalin-killed cells (FKC) from A. hydrophila. The control group was injected with phosphate buffered saline (PBS). All three antigens elicited strong immune responses. Respiratory burst and phagocytic activities in head kidney leukocytes and serum lysozyme activity peaked on day 21 after vaccination. Heavy chain gene transcription of immunoglobulin M and Z in the head kidney in vaccinated fish peaked on day 28. Relative percent survival was 83.3%, 72.2%, and 55.6% in the LPS, OMP, and FKC groups, respectively, but only 10% in control fish. Results suggest that LPS and OMP isolated from A. hydrophila can enhance specific immunity, non-specific immunity, and protection against A. hydrophila in fish. Thus, LPS and OMP could be important antigens for development of vaccines to control diseases caused by A. hydrophila in grass carp and other aquatic animals

Changes of Microorganisms and Flavor Compounds in the Fourth Round Jiupei of Sauce-flavored Baijiu in Beijing

Sauce-flavor Baijiu shows a typical sauce flavor, with a delicate mouthfeel. Its fermentation process consists of seven cycles, and each cycle produces one kind of base liquor. The fourth cycle liquor has a rich flavor and excellent quality. During the fermentation process, microorganisms are in a dynamic state, while flavor substances differ. This study investigated the microbial changes of Jiupei in the fourth cycle and their impact on flavor substances. Species diversity analysis was conducted on the fourth cycle Jiupei sample using high-throughput sequencing. Flavor substances were analyzed using headspace solid-phase microextraction combined with gas chromatography-mass spectrometry. Results showed that the dominant bacteria in the Jiupei were Lactobacillus, Virgibacillus, and Kroppenstedtia, while dominant fungi were Thermoascus, Aspergillus, and Issatchenkia. The microbial community in the Jiupei showed significant dynamic changes during the later stage of fermentation. The Jiupei showed the richest variety of alcohol and ester substances at the beginning of fermentation, with the relative content of alcohol, ester, and acid compounds showing a pattern of increasing firstly and then gradually decreased during fermentation. This study conducted a correlation analysis between fungi and bacteria at the genus level and flavor substances, revealing that Monascus, Lactobacillus, and Wickerhamomyces were positively correlated with key flavor substances, such as ethyl acetate, ethyl lactate, and ethyl hexanoate, respectively. The data provided a basis for comparing the microorganisms and flavor substances in the fourth cycle of sauce-flavor Baijiu, and offered a theoretical basis for improving the quality of Baijiu

Improving EFL Learners Language Written Production Using Subtitled Videos

English as a Foreign Language (EFL) Learners tend to produce their speech or written production as they are associated with what they see and what they hear. So, they are able and desired to give comment spontaneously after watching and listening to them. Producing written language can, as a matter of fact, be detected from learners\u27 fluency, accuracy and complexity. This article endeavors to elaborate written language production done by university students by using English subtitled videos. Two intact groups were assigned to accomplish two different tasks; that is, one group watched the video with subtitle and the other one without subtitle. The result of the study reveals that learners who carry out the tasks of watching video with subtitle improve their ability in written production in terms of fluency and accuracy regardless to complexity

Protective Effect of 18 β

Triptolide (TP) is the major active component of Tripterygium wilfordii Hook F (TWHF) and possesses multiple pharmacological effects. However, hepatotoxicity of TP which is one of the toxic properties slows its progression in clinical application. 18β-Glycyrrhetinic acid (GA) is the main bioactive ingredient of Licorice (Glycyrrhiza glabra L.), a herbal medicine famous for its detoxification. This study aims to investigate whether GA possesses protective effect against TP-induced hepatotoxicity in rats. TP interference markedly elevated serum levels of ALT, AST, and ALP, caused evident liver histopathological changes, and elevated hepatic TNF-α, IL-6, IL-1β, and IFN-γ as well as nuclear translocation of NF-κB. TP also significantly elevated liver MDA and declined hepatic activities of SOD, CAT, and GSH-Px. Assay of TUNEL and apoptosis proteins (Bax, Bcl-2, and active caspase-3) showed that TP induced severe hepatocellular apoptosis. In contrast, low-dose GA (50 mg/kg) significantly reversed TP-induced changes above. However, high-dose GA (100 mg/kg) had no such effect. Overall, these findings indicated that low-dose GA but not high-dose GA exhibited a protective effect against TP-induced hepatotoxicity in rats by anti-inflammation, antioxidation, and antiapoptosis, which suggests that the doses of GA/Licorice should be carefully considered when used together with TWHF or TWHF preparations

Development and bin mapping of gene-associated interspecific SNPs for cotton (Gossypium hirsutum L.) introgression breeding efforts

BACKGROUND: Cotton (Gossypium spp.) is the largest producer of natural fibers for textile and is an important crop worldwide. Crop production is comprised primarily of G. hirsutum L., an allotetraploid. However, elite cultivars express very small amounts of variation due to the species monophyletic origin, domestication and further bottlenecks due to selection. Conversely, wild cotton species harbor extensive genetic diversity of prospective utility to improve many beneficial agronomic traits, fiber characteristics, and resistance to disease and drought. Introgression of traits from wild species can provide a natural way to incorporate advantageous traits through breeding to generate higher-producing cotton cultivars and more sustainable production systems. Interspecific introgression efforts by conventional methods are very time-consuming and costly, but can be expedited using marker-assisted selection. RESULTS: Using transcriptome sequencing we have developed the first gene-associated single nucleotide polymorphism (SNP) markers for wild cotton species G. tomentosum, G. mustelinum, G. armourianum and G. longicalyx. Markers were also developed for a secondary cultivated species G. barbadense cv. 3–79. A total of 62,832 non-redundant SNP markers were developed from the five wild species which can be utilized for interspecific germplasm introgression into cultivated G. hirsutum and are directly associated with genes. Over 500 of the G. barbadense markers have been validated by whole-genome radiation hybrid mapping. Overall 1,060 SNPs from the five different species have been screened and shown to produce acceptable genotyping assays. CONCLUSIONS: This large set of 62,832 SNPs relative to cultivated G. hirsutum will allow for the first high-density mapping of genes from five wild species that affect traits of interest, including beneficial agronomic and fiber characteristics. Upon mapping, the markers can be utilized for marker-assisted introgression of new germplasm into cultivated cotton and in subsequent breeding of agronomically adapted types, including cultivar development. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2164-15-945) contains supplementary material, which is available to authorized users