Search Results (297)

Bedding-parallel fractures represent a crucial flow-path network in shale oil reservoirs, yet their timing of opening and driving mechanisms remain subjects of long-standing debate. This study investigates the origin and opening mechanisms of bedding-parallel fractures within the Paleogene Funing shale oil reservoir of the Huazhuang area, Subei Basin, eastern China. A combination of petrography, fluid-inclusion analysis, PVTx paleo-pressure modeling, hydrocarbon generation history modeling, and reflectance measurements was employed. The results reveal the presence of abundant oil inclusions and bitumen within the bedding-parallel veins, indicating that the initiation of fracture was essentially synchronous with the oil emplacement. The studied Funing shale, with vitrinite reflectance values of 0.85% to 1.04%, is mature, identifying it as an effective oil-prone source rock. Thermal maturity of bitumen is comparable to that of the host shale, suggesting a local oil source. Homogenization temperatures (T_h) of coeval aqueous inclusions record fracture opening temperatures of approximately 100–150 °C, consistent with oil-window conditions. By integrating T_h data with burial history modeling, the timing of fracture formation and coeval oil injection is constrained to the peak period of local hydrocarbon generation, rather than the Oligocene Sanduo tectonic event. This indicates that fracture opening was primarily associated with hydrocarbon generation rather than tectonic compression. Petroleum-inclusion thermodynamic modeling demonstrates that the bedding-parallel fracture opening occurred under moderate to strong overpressure conditions, with calculated paleo-pressure coefficients of ~1.35–2.36. This finding provides direct paleo-pressure evidence supporting the mechanism of bedding-parallel fracture opening driven by fluid overpressure created during oil generation. These oil-bearing, overpressured fluids facilitated the initial opening and subsequent propagation of fractures along the bedding planes of shales. Concurrently, the precipitation of the calcite veins may have been triggered by pressure drop associated with the expulsion of some coexisting aqueous fluids. This study provides evidence addressing the debated mechanisms of bedding-parallel fracture opening in organic-rich shales, highlighting the critical role of oil generation-induced overpressure. Full article

Background: Pelvic organ prolapse (POP) significantly impairs women’s quality of life (QoL), particularly in resource-limited settings where surgical options may be restricted. Vaginal pessaries provide a conservative and cost-effective treatment, yet local evidence on their effectiveness in Vietnam remains scarce. Methods: In this six-month prospective study, 130 women with stage II–IV POP received vaginal pessaries. QoL was evaluated using validated PFDI-20 and PFIQ-7 questionnaires, and changes in symptoms, satisfaction, and adverse events were analyzed. Results: Most women presented with advanced POP (65.4% stage III, 19.2% stage IV). Ring pessaries were most frequently used (64.6%), followed by Gellhorn (23.9%) and Donut (11.5%). Successful fitting was achieved in 95.4% of participants, with six women discontinuing use due to expulsion or discomfort. QoL scores improved significantly after six months: mean PFDI-20 total decreased from 78.5 ± 51.4 to 42.2 ± 38.3 (p < 0.001), and PFIQ-7 total decreased from 62.6 ± 43.2 to 25.1 ± 22.9 (p < 0.001), with all subscales showing consistent improvement. Nearly all women (98.5%) reported symptomatic improvement, and 95.4% were satisfied with treatment. Correlation analyses showed no significant relationships between POP stage and obstetric factors (vaginal delivery, macrosomia, and episiotomy). In multivariate regression analysis including only age, BMI, and POP stage, none were significantly associated with QoL improvement. Conclusions: Vaginal pessary use was safe, highly effective, and well tolerated, leading to symptom and QoL improvements among Vietnamese women with advanced POP. These findings support pessary use as a first-line management option, especially for women who are elderly, have comorbidities, or lack access to surgery. Full article

This study examined the spatial distribution of shamanic practice in contemporary South Korea, focusing on its territorial relationship with institutional religions. Contrary to portrayals of shamanism as a rural remnant or as absorbed by Pentecostal Christianity, population-adjust maps and spatial models reveal substantial concentrations in urban and peri-urban districts. Drawing on a geocoded dataset of 15,639 shamanic sites and 78,323 religious facilities across 229 districts, we estimated the ordinary least squares (OLS), spatial error models, and geographically weighted regression (GWR) models to evaluate how Protestant, Buddhist, and Catholic infrastructures were associated with shamanic site density. Protestant church density showed a consistent negative association with shamanic presence, strongest in regions with concentrated Protestant institutions. Buddhist temples had no uniform national effect but showed positive local associations in certain areas, suggesting localized symbiosis. Catholic sites displayed limited and inconsistent spatial relationships. These results demonstrate two contrasting dynamics: expulsion in Protestant strongholds and symbiosis, where Buddhist institutions allow more accommodation. Shamanism’s contemporary geography reflects adaptation to the territorial politics of institutional religion rather than a cultural revival. Full article

Huhehu Sag is a sag with high exploration degree in Hailar Basin. With large sedimentary thickness, complete stratigraphic development and excellent oil generation conditions, it is the main oil- and gas-producing sag in Hailar Basin. The primary source rocks are the Nantun Formation, with the Tongbomiao and Damoguaihe Formations as secondary sources. Hydrocarbon accumulation periods in the sag were comprehensively analyzed using methodologies including source rock hydrocarbon generation-expulsion history, authigenic illite dating of reservoirs, and fluid inclusion homogenization temperature analysis. Results reveal two major accumulation stages: Stage 1 (125–90 Ma), corresponding to the depositional period of the Yimin Formation, represented the peak paleo-geothermal regime and the primary hydrocarbon accumulation phase. Intensive hydrocarbon generation and expulsion, coupled with robust migration dynamics, facilitated large-scale oil and gas pooling. Stage 2(65 Ma-now), from the deposition of Qingyuangang Formation to the present, uplift and denudation reduce the burial depth of source rocks, the hydrocarbon generation intensity is weakened. This phase involved secondary adjustments of pre-existing reservoirs and continued charging of newly generated hydrocarbons. The Huhehu Sag is a typical half-graben structure. Fault-block and fault-lithologic reservoirs dominate, distributed zonally along gentle and steep slopes. Lithologic reservoirs primarily occur near or within the central hydrocarbon-generating sub-sags. The most favorable hydrocarbon accumulation zones are located in the sub-sag centers and adjacent areas with high-quality reservoirs. Full article

The Northern Tibetan Plateau Basin is the most extensive and least explored Mesozoic marine basin in China and shows considerable potential for oil and gas exploration. This study systematically analyzed the abundance, type, hydrocarbon generation potential, and conversion rate of organic matter within three Jurassic drill core samples from the Biloucuo area of the Northern Tibetan Plateau Basin. The total organic carbon (TOC) content of these Jurassic source rocks was >4%, on average, permitting their classification as excellent source rocks. The average contents of sapropelinite, exinite, vitrinite, and inertinite in kerogen were 74%, 4%, 18%, and 4%, respectively. The H/C and O/C ratios of the kerogen mainly ranged from 0.8 to 1.3 and 0.06 to 0.11, respectively, indicative of type II₁ kerogen. The average S₁ + S₂ content was 15.0 mg/g rock, indicating a high hydrocarbon generation potential. On the basis of the relationship between the quantity of soluble hydrocarbons remaining in the strata and the S₂ and TOC contents, it can be inferred that the hydrocarbon generation conversion rate of these Jurassic source rocks was between 25% and 50%, and partial hydrocarbon expulsion has taken place. It is estimated that the maximum oil generation potential of the formation will reach 20 kg/t rock at a greater depth, which equates to good exploration potential. Full article

Background/Objectives: The aim of this study is to analyze the frequency and type of subjective adverse events reported after the use of oxytocin and carbetocin in women giving birth by cesarean section. Methods: A total of 70 pregnant women, previously scheduled for elective cesarean section, were enrolled in this study and divided into two groups. One group (OXY) received intrapartum oxytocin at a dose of 5 IU intravenously, and the other group (CARBE) received intrapartum carbetocin at a dose of 100 μg intravenously. Both drugs were used alternately to contract the uterus immediately after the expulsion of baby during the cesarean section. Results: An analysis of reported subjective adverse symptoms associated with the administration of uterotonic drugs showed a higher incidence of adverse effects in the group of women receiving oxytocin compared to those receiving carbetocin. Statistical significance was observed for all of the following reported symptoms: headache, chest pain, burning sensation and heaviness in the chest, and palpitations. Conclusions: Although chest pain, burning and heaviness in the chest, palpitations, and headaches are more common in women giving birth by cesarean section after administration of oxytocin than after administration of carbetocin, this fact appears to be of limited clinical significance from a clinical point of view. Full article

Complications during pregnancy and parturition can lead to foetal hypoxia, which may be responsible for cardiac ischemia and the subsequent release of troponin from cardiac muscles into the amniotic fluid (AF) and bloodstream. So far, cardiac troponin T (cTnT) has only been measured in the blood samples of adult dogs, while no data on its presence and relevance in AF are available. This study aimed to determine whether cTnT can be detected in canine AF collected at birth. Furthermore, a possible correlation between amniotic cTnT concentration and maternal and neonatal outcomes was explored. For this purpose, 40 AF samples were collected from 14 bitches at the time of delivery. A commercially available ELISA kit was used for the analysis of canine cTnT in biological fluids. Cardiac troponin T was detected in all amniotic specimens with concentrations ranging from 74.1 to 318 ng/L (191.6 ± 66.4 ng/L). The dams’ morphotype, age, and weight, as well as the type of parturition (elective vs. emergency C-section) and the expulsion time of puppies, were significantly associated with amniotic cTnT concentrations. Although amniotic cTnT warrants further investigation to fully understand its clinical role in canine neonatology, these results suggest a promising and valuable contribution. Full article

Welding is a technological variant of the electric resistance spot-welding process in which the machined protrusion on the surface is heated and rapidly deformed, and the small molten zone formed at the interface is then forged to form the weld spot. The paper analyses the effects of projection welding parameter values for thin, low-carbon aluminized steel sheets. Two sets of 16 welded samples having three or five protrusions were performed and analyzed using the Taguchi method. The microstructural aspects were analyzed in cross sections made through the welded points, highlighting the expulsion or accumulated effects of the Al-Si alloy protective layer and the formation of intermetallic compounds. To estimate the effect of welding parameters, the samples were subjected to tensile strength tests, and the fracture mode was evaluated. It was found that the values of the breaking forces were close for the two types of samples analyzed, for identical values of the welding regime parameters, but the elongation at break was double in the case of samples with five protrusions. The breaking force increased from 10.9 kN for samples with three protrusions to 11.4 kN for samples with five protrusions, for the same values of welding parameters. Full article

This article treats the familiar triad “Gold, God, and Glory” as a heuristic to track how commercial, missionary, and reputational aims were configured within overlapping jurisdictions of the Portuguese world. Through three cases—the 1552 clash in Malacca between St. Francis Xavier and Captain D. Álvaro de Ataíde da Gama; the Gama family’s bargaining over offices and revenues; and the 1759 expulsion of the Society of Jesus—it argues that localized, negotiable frictions in the sixteenth century evolved into a structural confrontation by the mid-eighteenth century. Drawing on published Jesuit correspondence and secondary analyses of royal and municipal records, the study shows how missions initially supported metropolitan aims yet increasingly challenged them as Jesuit educational networks and revenue-bearing assets expanded. The Malacca dispute is read as a jurisdictional struggle over diplomatic access and rents, not merely a moral drama. The 1750 Treaty of Madrid and the Guaraní War further politicized perceptions of Jesuit wealth and influence, while the Lisbon-centered reform agenda after 1755 turned tension into rupture. Full article

The Baorao Trough of the Jiergalangtu Sag, located in the central Erlian Basin, is rich in petroleum resources. However, due to a lack of systematic geochemical characterization and comparative studies with other source rocks, the hydrocarbon generation potential of its Jurassic strata remains unclear. In this study, 125 samples from the Baorao Trough were analyzed to evaluate their hydrocarbon generation potential, identify organic matter sources and depositional environments, and characterize hydrocarbon generation and expulsion. Results show that source rocks from the first member of the Tengge’er (K₁bt₁) Formation and the Aershan (K₁ba) Formation have high organic matter content, favorable kerogen types, and have reached low to medium maturity. In contrast, Jurassic source rocks are predominantly Type III kerogen and highly mature. K₁bt₁ was deposited in a weakly oxidizing to reducing, brackish environment, while K₁ba formed under weakly reducing, saline conditions. Jurassic source rocks also developed in weakly reducing, brackish to saline settings. Notably, saline and reducing environments promote the development of high-quality source rocks. The lower total organic carbon (TOC) threshold for effective source rocks in the study area is 0.8%, and the hydrocarbon expulsion threshold for vitrinite reflectance ratio (R_o) is approximately 0.8%. Accordingly, K₁bt₁ and K₁ba have undergone partial hydrocarbon expulsion but remain within the oil-generating window, indicating strong oil-generating potential. Jurassic source rocks likely experienced early thermal cracking of Type III kerogen, with generated oil migrating or escaping during early geological activity. However, some gas-generating potential remains. These findings provide significant evidence for assessing resource potential, predicting the distribution of high-quality source rocks and favorable exploration areas. Full article

Emergency surfacing acts as the final line of defense in preserving the operational viability of submarines, playing a crucial role in their safety. To investigate the dynamic characteristics of submarine emergency surfacing, utilizing whole moving mesh technology, a method for coupled simulation of high-pressure air blowing out water tanks and emergency surfacing motion of submarines is proposed, enhancing the simulation’s fidelity to real-world dynamics. Based on meeting the requirements for simulation accuracy, utilizing the coupled simulation model, this study explored the effects of varying expulsion pressures on submarine motion parameters including depth, roll, pitch, and yaw angles. The findings indicate that the hull emerges slightly earlier and reaches a marginally higher point when coupling effects are accounted for compared to scenarios where these effects are neglected. At consistent expulsion pressures, as the pitch and roll angles increase and the back pressure decreases, the expulsion rate from the ballast tank accelerates. Higher expulsion pressures result in quicker surfacing of the hull, smaller amplitude of pitch angles, and larger amplitudes of roll angles, while the changes in yaw angle displayed no clear pattern. The methodologies and conclusions of this study offer valuable insights for the design and operational strategies of actual submarines. Full article

The direct visualization of the Meissner effect is achieved by mapping the expulsion of static magnetic fields from a high-${\mathrm{T}}_{\mathrm{C}}$ superconductor, specifically Yttrium Barium Copper Oxide (YBCO). This is accomplished using a miniaturized scanning magnetometer based on an ensemble of nitrogen-vacancy (NV) centers in diamond, operating under ambient room-temperature conditions. By comparing the magnetic field profiles above the YBCO sample at temperatures above and below its critical temperature $T_C$, we observe clear suppression and distortion of the magnetic field in the superconducting state. These observations are consistent with both magnetic simulations and expected characteristics of the Meissner effect. This work introduces a novel and practical method for visualizing the Meissner effect, offering potential applications in educational demonstrations and the diagnostic testing of superconductivity using room-temperature quantum magnetometry. Full article

This study investigates the uplift and exhumation history of the southern segment of the western margin of the Ordos Basin using low-temperature thermochronology, including zircon (U-Th)/He (ZHe), apatite fission-track (AFT), and apatite (U-Th)/He (AHe) data, combined with thermal history modeling. The study area exhibits a complex structural framework shaped by multiple deformation events, leading to the formation of extensively developed fault systems. Such faulting can adversely affect hydrocarbon preservation. To better constrain the timing of fault reactivation in this area, we carried out an integrated study involving low-temperature thermochronology and burial history modeling. The results reveal a complex, multi-phase thermal-tectonic evolution since the Late Paleozoic. The ZHe ages (291–410 Ma) indicate deep burial and heating related to Late Devonian–Early Permian tectonism and basin sedimentation, reflecting early orogenic activity along the western North China Craton. During the Late Jurassic to Early Cretaceous (165–120 Ma), the study area experienced widespread and differential uplift and cooling, controlled by the Yanshanian Orogeny. Samples on the western side of the fault show earlier and more rapid cooling than those on the eastern side, suggesting a fault-controlled, basinward-propagating exhumation pattern. The cooling period indicated by AHe data and thermal models reflects the Cenozoic uplift, likely induced by far-field compression from the rising northeastern Tibetan Plateau. These findings emphasize the critical role of inherited faults not only as thermal-tectonic boundaries during the Mesozoic but also as a pathway for hydrocarbon migration. Meanwhile, thermal history models based on borehole data further reveal that the study area underwent prolonged burial and heating during the Mesozoic, reaching peak temperatures for hydrocarbon generation in the Late Jurassic. The timing of major cooling events corresponds to the main stages of hydrocarbon expulsion and migration. In particular, the differential uplift since the Mesozoic created structural traps and migration pathways that likely facilitated hydrocarbon accumulation along the western fault zones. The spatial and temporal differences among the samples underscore the structural segmentation and dynamic response of the continental interior to both regional and far-field tectonic forces, while also providing crucial constraints on the petroleum system evolution in this tectonically complex region. Full article

Intratumoral injections of macromolecules, such as biologics and immunotherapeutics, show promise in overcoming dose-limiting side effects associated with systemic injections and improve treatment efficacy. However, the retention of injectates in the tumor microenvironment is a major underappreciated challenge. High interstitial pressures and dense tumor architectures create shear forces that rapidly expel low-viscosity solutions post-injection. Injectable hydrogels may address these concerns by providing a viscoelastic delivery vehicle that shields loaded therapies from rapid expulsion from the tumor. A chitosan–glycerol hydrogel was thus developed and characterized with the goal of improving the injection retention of loaded therapeutics. The gelation parameters and mechanical properties of the hydrogel were explored to reveal a shear-thinning gel that is injectable through a 27-gauge needle. Biocompatibility studies demonstrated that the chitosan–glycerol hydrogel was nontoxic. Retention studies revealed significant improvements in the retention of model therapeutics when formulated with the chitosan–glycerol hydrogel compared to less-viscous solutions. Finally, release studies showed that there was a sustained release of model therapeutics of various molecular sizes from the hydrogel. Overall, the chitosan–glycerol hydrogel demonstrated injectability, enhanced retention, biocompatibility, and sustained release of macromolecules, indicating its potential for future clinical use in intratumoral macromolecule delivery. Full article

Porosity and roughened surfaces of implant materials have been shown to lead to improved cellular attachment and enhanced osseointegration. These topography changes in the surface also aid in the mechanical interlocking of the material to the bone. Polyetheretherketone (PEEK) has emerged as a popular alternative to titanium-based implants due to its lack of stress-shielding effect, radiolucency, and high chemical resistance. However, PEEK is bioinert, thus requiring surface modifications to elicit appropriate cellular responses that lead to successful osteointegration of the material in vivo. Sulfonation is a process used to modify the surface of PEEK, which can be controlled by varying parameters such as soak time and soak temperature, thereby fabricating a porous surface on the material. This work aimed to ensure the repeatability of a previously optimized sulfonated and hydrothermally treated PEEK surface and subsequently observe the mechanical properties, bacterial attachment, and cellular response of pre-osteoblast MC3T3-E1 cells on the surface. This study found that while all PEEK surfaces had similar cell and Staphylococcus aureus attachment, the sulfonated and hydrothermally treated PEEK (peak mean load of 605 N, p ≤ 0.0001) and the sulfonated only PEEK (peak mean load of 495 N, p = 0.0240) had a higher level of performance in expulsion testing than smooth PEEK due to its mechanical interlocking ability. Imaging and contact angle analysis confirm that a surface with repeatable porosity can be achieved. Full article