Research on geophysical response analysis and prediction technology of geostress in the shale gas area of the southern Sichuan Basin

The exploration and development potential of shale gas reservoirs in the Sichuan Basin is enormous; however, it also faces difficulties such as complex structures, strong heterogeneity, and unclear geophysical response characteristics. Fine prediction of geostress is an important part of shale gas exploration and development, which directly affects the implementation effect of reservoir evaluation, well trajectory design, and fracture reconstruction. The existing geostress prediction techniques lack high-precision seismic data constraints, making it difficult to accurately reflect the planar distribution characteristics of geostress in the block with rapid changes in complex tectonic zones. At the same time, the geophysical response characteristics of geostress in the Sichuan Basin are unknown, and the geostress seismic prediction technology lacks theoretical basis. This paper combines numerical simulation and physical experiments and defines the characteristics of the geophysical response of shale gas reservoirs in the Sichuan Basin changing with the stress field, and technical countermeasures for geostress seismic prediction have been established to provide technical means for accurate prediction of the geostress field in the shale gas block. Based on the geostress sensitive parameters obtained from prestack seismic inversion, the geostress field prediction of a shale gas work area in the Sichuan Basin is realized

Bloodstream infection, peritonitis, and pneumonia caused by Pasteurella multocida in a patient with liver cirrhosis despite no animal contact: case report and literature review

Pasteurella multocida is an opportunistic pathogen. Previously reported infections associated with P. multocida have often been linked to contact with cats, dogs, and other animals. Cases of systemic multiple-site infections following P. multocida infection are rare. This case study presents a 49-year-old middle-aged man with post-hepatitis B cirrhosis and no history of animal contact. The patient was admitted with symptoms of fever accompanied by diarrhea, abdominal distension, and cough. Blood tests showed elevated levels of CRP, PCT, and IL-6, and blood culture revealed the growth of P. multocida. CT scans revealed a large amount of abdominal effusion, a small amount of pleural effusion, and pulmonary infection foci. The patient’s condition improved after successive administration of ceftriaxone and levofloxacin to fight the infection, and abdominal puncture and drainage. Multiple-site infections caused by P. multocida are rarely encountered in patients with liver cirrhosis but without animal contact, which could be regarded as serious conditions warranting careful attention in terms of clinical diagnosis and treatment

Possible Luttinger liquid behavior of edge transport in monolayer transition metal dichalcogenide crystals.

In atomically-thin two-dimensional (2D) semiconductors, the nonuniformity in current flow due to its edge states may alter and even dictate the charge transport properties of the entire device. However, the influence of the edge states on electrical transport in 2D materials has not been sufficiently explored to date. Here, we systematically quantify the edge state contribution to electrical transport in monolayer MoS2/WSe2 field-effect transistors, revealing that the charge transport at low temperature is dominated by the edge conduction with the nonlinear behavior. The metallic edge states are revealed by scanning probe microscopy, scanning Kelvin probe force microscopy and first-principle calculations. Further analyses demonstrate that the edge-state dominated nonlinear transport shows a universal power-law scaling relationship with both temperature and bias voltage, which can be well explained by the 1D Luttinger liquid theory. These findings demonstrate the Luttinger liquid behavior in 2D materials and offer important insights into designing 2D electronics

Terahertz-driven irreversible topological phase transition in two-dimensional MoTe2_{2}

Recent discoveries of broad classes of quantum materials have spurred fundamental study of what quantum phases can be reached and stabilized, and have suggested intriguing practical applications based on control over transitions between quantum phases with different electrical, magnetic, and$/$or optical properties. Tabletop generation of strong terahertz (THz) light fields has set the stage for dramatic advances in our ability to drive quantum materials into novel states that do not exist as equilibrium phases. However, THz-driven irreversible phase transitions are still unexplored. Large and doping-tunable energy barriers between multiple phases in two-dimensional transition metal dichalcogenides (2D TMDs) provide a testbed for THz polymorph engineering. Here we report experimental demonstration of an irreversible phase transition in 2D MoTe$_{2}$ from a semiconducting hexagonal phase (2H) to a predicted topological insulator distorted octahedral ($1T^{'}$) phase induced by field-enhanced terahertz pulses. This is achieved by THz field-induced carrier liberation and multiplication processes that result in a transient high carrier density that favors the $1T^{'}$ phase. Single-shot time-resolved second harmonic generation (SHG) measurements following THz excitation reveal that the transition out of the 2H phase occurs within 10 ns. This observation opens up new possibilities of THz-based phase patterning and has implications for ultrafast THz control over quantum phases in two-dimensional materials

Nanocone Decorated ZnO Microspheres Exposing the (0001) Plane and Enhanced Photocatalytic Properties

WZ thanks EPSRC for a platform grant (No. EP/K015540/1) and financial support to the Electron Microscopy Laboratory (No. EP/F019580/1)ZnO spherical particles exposing only the (0001) planes were prepared by an established solvothermal method using a water‒ethylene glycol (EG) mix as a solvent. It was found that poorly crystalline nanoparticles formed first, followed by their aggregation into microspheres consisting of crystallites embedded in ethylene glycol and precursor molecules/ions. The grown up nanocrystallites and nanocones in the microspheres are all radially aligned. The possible formation mechanisms, in particular, the roles of water molecules, ethylene glycol and the intrinsic dipolar field of ZnO crystals, are discussed. X-ray photoelecton spectroscopy (XPS) experiments indicated the spherical particles were terminated solely by zinc atoms. Brunauer-Emmett-Teller (BET) measurements in conjunction with the degradation of methylene blue (MB) dye data demonstrated that the photocatalytic performance of the ZnO spheres depended on the growth time and was significantly improved compared to traditional ZnO nanorods. This study is a rare example which combines nanostructural characterisation of ZnO particles terminated with a single (0001) plane of known Zn2+-polarity with their photocatalytic performance.PostprintPeer reviewe

Dedifferentiation process driven by radiotherapy-induced HMGB1/TLR2/YAP/HIF-1α signaling enhances pancreatic cancer stemness

Differentiated cancer cells reacquiring stem cell traits following radiotherapy may enrich cancer stem cells and accelerate tumor recurrence and metastasis. We are interested in the mechanistic role of dying cells-derived HMGB1 in CD133− pancreatic cancer cells dedifferentiation following radiotherapy. We firstly confirmed that X-ray irradiation induced differentiation of CD133− pancreatic cancer cells, from either sorted from patient samples or established cell lines, into cancer stem-like cells (iCSCs). Using an in vitro coculture model, X-ray irradiation induced dying cells to release HMGB1, which further promoted CD133− pancreatic cancer cells regaining stem cell traits, such as higher sphere forming ability and expressed higher level of stemness-related genes and proteins. Inhibiting the expression and activity of HMGB1 attenuated the dedifferentiation stimulating effect of irradiated, dying cells on C133− pancreatic cancer cells in vitro and in PDX models. Mechanistically, HMGB1 binding with TLR2 receptor functions in a paracrine manner to affect CD133− pancreatic cancer cells dedifferentiation via activating Hippo-YAP pathway and HIF-1α expression in oxygen independent manner in vitro and in vivo. We conclude that X-ray irradiation induces CD133− pancreatic cancer cell dedifferentiation into a CSC phenotype, and inhibiting HMGB1 may be a strategy to prevent CSC enrichment and further pancreatic carcinoma relapse.</p