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result(s) for
"Pan, Shuxin"
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Genetic and biological properties of H7N9 avian influenza viruses detected after application of the H7N9 poultry vaccine in China
2021
The H7N9 avian influenza virus (AIV) that emerged in China have caused five waves of human infection. Further human cases have been successfully prevented since September 2017 through the use of an H7N9 vaccine in poultry. However, the H7N9 AIV has not been eradicated from poultry in China, and its evolution remains largely unexplored. In this study, we isolated 19 H7N9 AIVs during surveillance and diagnosis from February 2018 to December 2019, and genetic analysis showed that these viruses have formed two different genotypes. Animal studies indicated that the H7N9 viruses are highly lethal to chicken, cause mild infection in ducks, but have distinct pathotypes in mice. The viruses bound to avian-type receptors with high affinity, but gradually lost their ability to bind to human-type receptors. Importantly, we found that H7N9 AIVs isolated in 2019 were antigenically different from the H7N9 vaccine strain that was used for H7N9 influenza control in poultry, and that replication of these viruses cannot, therefore, be completely prevented in vaccinated chickens. We further revealed that two amino acid mutations at positions 135 and 160 in the HA protein added two glycosylation sites and facilitated the escape of the H7N9 viruses from the vaccine-induced immunity. Our study provides important insights into H7N9 virus evolution and control.
Journal Article
Genetic and biological characteristics of the globally circulating H5N8 avian influenza viruses and the protective efficacy offered by the poultry vaccine currently used in China
2022
The H5N8 avian influenza viruses have been widely circulating in wild birds and are responsible for the loss of over 33 million domestic poultry in Europe, Russia, Middle East, and Asia since January 2020. To monitor the invasion and spread of the H5N8 virus in China, we performed active surveillance by analyzing 317 wild bird samples and swab samples collected from 41,172 poultry all over the country. We isolated 22 H5N8 viruses from wild birds and 14 H5N8 viruses from waterfowls. Genetic analysis indicated that the 36 viruses formed two different genotypes: one genotype viruses were widely detected from different wild birds and domestic waterfowls; the other genotype was isolated from a whopper swan. We further revealed the origin and spatiotemporal spread of these two distinct H5N8 virus genotypes in 2020 and 2021. Animal studies indicated that the H5N8 isolates are highly pathogenic to chickens, mildly pathogenic in ducks, but have distinct pathotypes in mice. Moreover, we found that vaccinated poultry in China could be completely protected against H5N8 virus challenge. Given that the H5N8 viruses are likely to continue to spread in wild birds, vaccination of poultry is highly recommended in high-risk countries to prevent H5N8 avian influenza.
Journal Article
Triassic Intracontinental Crustal Reworking of the Eastern Tianshan: New Insights From Late Triassic Adakitic and Low‐Sr/Y Granitoids in the Bogda Range
2025
Continental intraplate magmatism remains a fundamental challenge in Plate Tectonics. Triassic magmatism represents a critical phase in the evolution of the Central Asian Orogenic Belt and continues to provoke debate about its tectonic setting. This study presents an integrated analysis of field, petrographic, geochronologic, geochemical, and isotopic data from two newly identified Triassic granitoids in the Bogda Range: an adakitic porphyry and a low‐Sr/Y granite porphyry. Zircon U‐Pb dating yields nearly coeval crystallization ages of 221–220 Ma and 219–217 Ma, respectively. Both granitoids are characterized by high SiO2 and K2O content, low MgO (Mg#) and Ni content, and elevated K2O/Na2O and Th/Nb ratios. They have also depleted whole‐rock Sr‐Nd and zircon Hf isotopic compositions, indicative of juvenile crustal sources. The adakitic porphyry exhibits high Sr/Y and (La/Yb)N ratios, low Rb/Sr ratios, and weak Eu anomalies, suggesting derivation from garnet‐stable mafic lower crust. In contrast, the granite porphyry displays low Sr/Y and (La/Yb)N ratios, consistent with a plagioclase‐stable source. By integrating these results with regional data, we propose that the diversity of Triassic magmatism in the Eastern Tianshan is due to the reworking of juvenile and ancient crust at different depths and temperatures, resulting in arc‐like geochemical signatures. This process was associated with transcurrent tectonics and variable mantle contributions in a continental intraplate setting.
Journal Article
The secondary pore development model of coarse-grained deposition: A case study of the Xiazijie Formation in the Northwestern Margin of the Junggar Basin
2023
The coarse-grained glutenite rock mass of the proximal fan delta is characterized by the blocky texture, mixing of gravels with varied sizes, high mud content, and low porosity and permeability, leading to difficulties in assessment and exploration of oil and gas enrichment regularities of tight glutenite. The Permian Xiazijie Formation in the northwest margin of Junggar Basin has a set of tight glutenite reservoirs, and the reservoir quality is an important controlling factor for oil and gas enrichment. Based on three-dimensional earthquake, casting thin sections, rock physical property, geochemistry, the sedimentary facies division, petrologic features, physical property regularities, pore types and diagenesis of Xiazijie Formation were analyzed. This research develops the pore evolution model of the coarse-grained deposition via the quantitative analysis of porosity evolution. First, during the rapid compaction, intensive mechanical compaction results in reduction of the original porosity from 29.8% to 15.1%. Secondly, the cement formed during the eodiagenesis destructs the reservoir space and leads to an average porosity loss of 6.5%. Third, dissolution effectively improves reservoir quality. It mainly dissolves the zeolite cement, and the porosity grows to 12.1% from 8.6%. The dissolution occurs during the main hydrocarbon expulsion stage of the source rock, which is in favor of hydrocarbon emplacement. Fourth, during the telodiagenesis with the deepening burial and intensifying pressure solution, siliceous and carbonate cement precipitate, the reservoir physical property is degraded again, the porosity loss is about 3.4%. After a series of complex diagenetic processes, the current tight glutenite reservoir comes into being, with the porosity of about 8.7%. The research results provide theoretical reference for coarse-grained glutenite reservoir prediction.
Journal Article
Quantifying the effects of different hydrocarbon charging periods on reservoir quality: A case study of the Upper Wuerhe Formation, Junggar Basin, NW China
2024
Mineral dissolution and precipitation is an important factor affecting pore genesis and hydrocarbon accumulation in sedimentary basins. Differential diagenetic processes at different hydrocarbon charging periods generally cause disparate effects on reservoir quality, which is important for reservoir evaluation and prediction. Focusing on this question, petrologic work, quantitative analysis on reservoir quality including porosity, permeability, and micro-scale X-ray computer tomography were conducted in conglomeratic reservoirs of the late Permian Upper Wuerhe Formation (P3w) in the Shawan Sag, Junggar Basin, northwestern China. The results show that tuff and volcanic debris are enriched in the formation. Laumontites generally occur as cements in the reservoirs due to the alteration of volcanic materials and small amounts of early-stage calcite precipitated during eodiagenesis. Partial laumontite and calcite cements, as well as some debris and feldspar, are differentially dissolved due to differential hydrocarbon charging. During the continuous compaction of the reservoir, first-stage hydrocarbon charging occurred in the middle Jurassic when primary porosity almost disappeared. Hydrocarbon charging inhibited the precipitation of laumontite and calcite, promoting their dissolution. Second-stage hydrocarbon charging in the early Cretaceous further caused more extensive dissolution of laumontite and calcite, forming more than 70% secondary porosity. Authigenic quartz, kaolinite, and late-stage calcite are precipitated as the associated minerals of laumontite dissolution. This study presents the significance of reservoir reconstruction after hydrocarbon charging and suggests prospective hydrocarbon accumulations in deeply buried clastic reservoirs when hydrocarbon supply is sufficient from source rocks.
Journal Article
Characteristics and controlling factors of glutenite reservoir rock quality of retrogradational fan Delta
2021
The glutenite reservoir rock of the fan delta facies is associated with a complex sedimentary environment and high heterogeneity, and by far the characteristics and controlling factors of the reservoir rock quality have not been well understood. By comprehensively investigating the lithofacies, petrology, physical properties and diagenesis of the Upper Wuerhe Formation of the Mahu Sag, the Junggar Basin, it is concluded that the Upper Wuerhe Formation develops three major groups of lithofacies, totally consisting of 11 sub-types, and reservoir rock properties of different lithofacies are greatly varied. This research shows that the lithofacies attributed to the tractive current and density current have well-sorted rock particles, low mud content, welldeveloped secondary dissolved pores, and thus high overall reservoir rock quality. On the contrary, the lithofacies based on debris flow and sheet flow, are observed with high mud content, suppressed development of intergranular and dissolved pores, and thus poor reservoir rock quality. The system tract controls the macro variation of the reservoir rock quality. The best quality is found in the highstand system tract, followed by those of the lake transgression and at last lowstand system tracts. The micro variation of the reservoir rock quality is determined by the mud content, rock particle size and dissolution. The muddy matrix mainly damages the pore connectivity, and presents the strongest correlation with permeability. The reservoir rock with concentrated particle sizes and well-sorted particles has quality better than those of reservoir rocks composed of excessively large or small particles. Dissolution effectively improves the storage capability of the reservoir rock, resulting in an average porosity increment by 4.2%.
Journal Article
Formation Mechanism and Prediction Method for the Permian Fused Breccia Tuff Reservoir, Wuxia Region, Junggar Basin
2021
Fused breccia tuff occurs globally, but its formation mechanism is very controversial. Volcanic reservoirs have developed at the bottom of the Permian Fengcheng Formation in the Wuxia region of the Junggar Basin, and here, the lithology is fused breccia tuff. The reservoir porosity is mainly vesicles, but the development and relative filling of the vesicles vary spatially, resulting in strong reservoir heterogeneity. Through core and thin section observations and structural analysis, and combined with reconstructions of the paleosedimentary environment, we discussed in detail the formation mechanism of the fused breccia tuff reservoir. Our conclusions are as follows. In the high-temperature and high-pressure environment of the deep crust, intermediate acidic lava containing volatile components rapidly rose to the earth’s surface along a fault. The volatile components in the lava foamed strongly and then exploded due to the sharp decline of pressure and temperature. A small part of the volcanic dust and pyroclastic material was erupted into the upper atmosphere. Most of the magma became magmatic pyroclast, vitric pyroclast, rock debris, dust, and other matter. This material was in a semimolten state and overflowed into a nearby low-lying lake. The extremely high-temperature pyroclastic flow quickly vaporized the water into high-pressure water vapor, which was squeezed into the pyroclastic flow and became mixed with other volatiles in the foam. On cooling, the pyroclastic material solidified into rock, and the vesicles were preserved. In a later period, due to strong tectonic movement, faults and fractures developed, surface water penetrated into the vesicles along the faults and fractures, and silica and other substances were deposited, filling the primary vesicles. To quantify the development and relative filling of vesicles, drilling parameters were used to establish different geologic models, and wave equation forward modeling was used to obtain a relationship between the development and filling of vesicles, and the seismic amplitude. The 3D seismic amplitude attributes were then extracted to predict the extent of the reservoir, yielding prediction results consistent with the drilling observations.
Journal Article
Effective Cellulase Production by Trichoderma reesei Using Solid and Liquid Inducers Mixture with Varying Ratios
2024
Cellulase serves as a pivotal enzymatic catalyst in the bioconversion of lignocellulosic biomass into fermentable sugars and subsequent bioproducts. However, its high cost poses a significant challenge, making the overall lignocellulosic biorefinery process economically burdensome. To mitigate this issue and enhance cost-effectiveness, it becomes imperative to employ in-house built and highly potent cellulases. This study focused on effective cellulase production by
Trichoderma reesei
RUT C30 and PB3 strains using solid and liquid inducers mixture with varying ratios. By optimizing the SLI mixture at a ratio of 1:5 (w/w), we successfully attained maximum cellulase production and productivity, reaching 29.5 FPU/mL and 204.8 FPU/L/h, respectively. Furthermore, this strategy yielded comparatively elevated levels of cellobiase and xylanase production, achieving 69.6 CBU/mL and 250.1 IU/mL, respectively, in contrast to the control process utilizing either solid or liquid inducers. Ultimately, hydrolysis of 10% (w/v) H
2
SO
4
-pretreated corn stover (HPCS) utilizing a crude enzyme dosage of 15 FPU/g-HPCS liberated 45.5 g/L of glucose and 18.2 g/L of xylose, underscoring the immense potential of this methodology in alleviating the cost burden associated with lignocellulosic biorefinery.
Journal Article
Different Targeting Ligands-Mediated Drug Delivery Systems for Tumor Therapy
2024
Traditional tumor treatments have the drawback of harming both tumor cells and normal cells, leading to significant systemic toxic side effects. As a result, there is a pressing need for targeted drug delivery methods that can specifically target cells or tissues. Currently, researchers have made significant progress in developing targeted drug delivery systems for tumor therapy using various targeting ligands. This review aims to summarize recent advancements in targeted drug delivery systems for tumor therapy, focusing on different targeting ligands such as folic acid, carbohydrates, peptides, aptamers, and antibodies. The review also discusses the advantages, challenges, and future prospects of these targeted drug delivery systems.
Journal Article