Hydraulic Fracturing Mechanism in Reservoirs with a Linear Inclusion Fissure

Hydraulic fracturing technology is widely used in most oil-water wells to improve production. However, the mechanism of fracturing in a reservoir with inclusion fissures is still unclear. In this study, a theoretical model was developed to determine the stress distribution during hydraulic fracturing. The line inclusion fissure was regarded as a thin bar and the stress around the artificial fracture, which is affected by a single line inclusion, was determined using the Eshelby equivalent inclusion theory. Stress intensity factors at the tip of both the artificial fracture and the inclusion were achieved, and initiation of the fracture was predicted. Furthermore, to validate the theoretical model, re-fracturing experiments were performed on a large-scale tri-axial system. The results showed that the defects reduce the intensity of the rock, which introduces the possibility that more complex fractures emerge in the reservoir. The results also showed that the fracture direction is governed by far-field stress. The obtained conclusions are helpful to better understand the mechanism of hydraulic fracturing in reservoirs

SA-Solver: Stochastic Adams Solver for Fast Sampling of Diffusion Models

Diffusion Probabilistic Models (DPMs) have achieved considerable success in generation tasks. As sampling from DPMs is equivalent to solving diffusion SDE or ODE which is time-consuming, numerous fast sampling methods built upon improved differential equation solvers are proposed. The majority of such techniques consider solving the diffusion ODE due to its superior efficiency. However, stochastic sampling could offer additional advantages in generating diverse and high-quality data. In this work, we engage in a comprehensive analysis of stochastic sampling from two aspects: variance-controlled diffusion SDE and linear multi-step SDE solver. Based on our analysis, we propose SA-Solver, which is an improved efficient stochastic Adams method for solving diffusion SDE to generate data with high quality. Our experiments show that SA-Solver achieves: 1) improved or comparable performance compared with the existing state-of-the-art sampling methods for few-step sampling; 2) SOTA FID scores on substantial benchmark datasets under a suitable number of function evaluations (NFEs)

Understanding the unique mechanism of ferroptosis: a promising therapeutic target

Ferroptosis is an iron-dependent form of regulated cell death and is characterized by high concentrations of intracellular lipid peroxide and a redox imbalance in the cells. Ferroptosis shows distinct morphological and biological features compared with other prominent mechanisms of programmed cell death. The distinct characteristics of ferroptosis include the dysfunction of the lipid peroxide repair enzyme glutathione peroxidase 4, the presence of ferrous iron overload, and the lipid peroxidation of polyunsaturated fatty acids. Several other metabolic pathways (including iron, lipid, and amino acid metabolism) and ferritinophagy, as well as transcription factors, can modulate ferroptosis. However, to date, the molecular mechanism of ferroptosis has not been elucidated. This review outlines the discovery, characterization, regulatory mechanisms, and crosstalk of ferroptosis. Further, we have noted the controversial elements in the ferroptosis-related mechanisms. Our inferences may provide a partial reference for developing strategies to regulate ferroptosis

A Nonlinear Wind Turbine Wake Expansion Model Considering Atmospheric Stability and Ground Effects

This study investigates the influence of atmospheric stability and ground effects on wind turbine wake recovery, challenging the conventional linear relationship between turbulence intensity and wake expansion coefficient. Through comprehensive field measurements and numerical simulations, we demonstrate that the linear wake expansion assumption is invalid at far-wake locations under high turbulence conditions, primarily due to ground effects. We propose a novel nonlinear wake expansion model that incorporates both atmospheric stability and ground effects by introducing a logarithmic relationship between the wake expansion coefficient and turbulence intensity. Validation results reveal the superior prediction accuracy of the proposed model compared to typical engineering wake models, with root mean square errors of wake wind speed predictions ranging from 0.04 to 0.063. The proposed model offers significant potential for optimizing wind farm layouts and enhancing overall wind energy production efficiency

Cross-cultural adaptation and validation of the PedsQL™ stem cell transplant module in China: A methodological and cross-sectional study

BackgroundHematopoietic stem cell transplantation (HSCT), as a mature technology, has significantly improved the survival rate of children. However, there lack efficient scales to assess the quality of life (QoL) of children with HSCT in China, which has important implications in the care of this population. This study aimed to translate the original English Pediatric Quality of Life Inventory™ (PedsQL™) Stem Cell Transplant Module into a Chinese mandarin version, and evaluate its reliability.MethodsChildren of ages 2–18 years who had received HSCT at Children's Hospital of Nanjing Medical University and Children's Hospital of Fudan University were recruited. Children or their parents were asked to fill the PedsQL™ 4.0 Generic Core Scales, PedsQL™ Stem Cell Transplant Module, and PedsQL™ Family Information Form. Feasibility was evaluated by completion rate and the percentage of missing items, reliability by the internal consistency and test-retest reliability, and validity by factor analysis and correlation analysis between the scores of total scale and each dimension.ResultsA total of 120 children (mean age 6.37, SD = 3.674) and some parents were included. A low percentage of items were missed in returned reports. Cronbach's alpha coefficient reached 0.70 in the majority of dimensions of both child self-report and parent proxy-report. Test-retest reliability was 0.685 in parents' forms and 0.765 in child's forms. Eight factors were extracted, with a cumulative contribution rate of 74.54%. The correlation between PedsQL™ 4.0 and Transplant Module was 0.748 for children self-report and 0.808 for parent proxy-report.ConclusionsThis study provides evidence that the Chinese mandarin version of the PedsQL™ Stem Cell Transplant is feasible, reliable and valid in evaluating the QoL of Chinese children after HSCT

De novo mutations in SMCHD1 cause Bosma arhinia microphthalmia syndrome and abrogate nasal development

Bosma arhinia microphthalmia syndrome (BAMS) is an extremely rare and striking condition characterized by complete absence of the nose with or without ocular defects. We report here that missense mutations in the epigenetic regulator SMCHD1 mapping to the extended ATPase domain of the encoded protein cause BAMS in all 14 cases studied. All mutations were de novo where parental DNA was available. Biochemical tests and in vivo assays in Xenopus laevis embryos suggest that these mutations may behave as gain-of-function alleles. This finding is in contrast to the loss-of-function mutations in SMCHD1 that have been associated with facioscapulohumeral muscular dystrophy (FSHD) type 2. Our results establish SMCHD1 as a key player in nasal development and provide biochemical insight into its enzymatic function that may be exploited for development of therapeutics for FSHD

Tandem autologous hematopoietic stem cell transplantation for treatment of adult T-cell lymphoblastic lymphoma: a multiple center prospective study in China

T-cell lymphoblastic lymphoma (T-LBL) is a highly aggressive form of lymphoma with poor clinical outcomes and lacks of a standard treatment regimen. In this study, we assessed the safety and efficacy of tandem autologous hematopoietic stem cell transplantation (auto-HSCT) strategy for adult T-LBL and evaluated prognostic factors affecting survival. 181 Newly-diagnosed adult T-LBL patients were enrolled, 89 patients were treated with chemotherapy alone, 46 patients were allocated to single auto-HSCT group, 46 patients were treated with tandem auto-HSCT. The median follow-up time was 37 months, the 3-year progression/relapse rate of the tandem auto-HSCT group was significantly lower than that of the single auto-HSCT group and chemotherapy group (26.5% vs 53.1% and 54.8%). The 3-year PFS and OS rate of the tandem auto-HSCT group (73.5% and 76.3%) were significantly higher than those of the single auto-HSCT group (46.9% and 58.3%) and the chemotherapy group (45.1% and 57.1%). In the tandem auto-HSCT group, age and disease status after the first transplantation impacted the OS and PFS. Multivariate analysis identified that disease status after the first transplantation was the only independent prognostic factor for patients treated with tandem-HSCT. In addition, diagnostic models of the initial CD8+CD28+/CD8+CD28- T cell ratio in predicting the disease status were found to be significant. Taken together, tandem auto-HSCT can be considered an optimal strategy for adult T-LBL patients (ChiCTR-ONN-16008480)

RNA regulons in Hox 5'UTRs confer ribosome specificity to gene regulation and embryonic development

Historically, the ribosome has been viewed as a ribozyme with constitutive rather than regulatory capacity in mRNA translation. However, emerging studies reveal that ribosome activity may be highly regulated to impart a new layer of specificity in control of gene expression and organismal biology. Heterogeneity in the composition of the ribosome may generate variations to the translation machinery that significantly impact on how the genomic template is translated into functional proteins. Studies in our laboratory have shown that ribosomal protein RPL38 confers specificity to the ribosome and is responsible for specifically translating a subset of Homeobox (Hox) mRNAs to regulate the mammalian body plan. In Rpl38 mutant embryos, global protein synthesis is unchanged while the translation of 8 of the 39 Hox mRNAs is specifically affected. Unexpectedly, Rpl38 transcripts are highly enriched in a tissue specific manner, most notably in somites and within the neural tube. Together, these studies led us to propose that ribosome in distinct regions of the embryo may be highly specialized to exert transcript-specific translational control. However how transcripts are recognized and selected by RPL38 remains unknown.Here I uncover a unique set of RNA regulons embedded in the 5'UTRs of Hox genes which are critical for ribosome-directed control of their spatiotemporal expression patterns. These structured RNA elements, resembling Viral Internal Ribosome Entry Sites (IRES), are positioned close to the AUG of subsets of Hox mRNA to interact with ribosomal proteins and directly recruit the ribosome. Using Hoxa9 as a model, I find that the IRES element folds into a stable structure in vitro and can recruit ribosomes directly to the mRNA. By generating the first targeted knock-out of an IRES element in the mouse, I show that the Hoxa9 transcript, despite numerous layers of transcriptional control, requires an IRES-element for accurate spatiotemporal expression and axial skeletal patterning. The unexpected requirement for specialized translation control of Hox transcripts is further explained by the activity of a novel Translational Inhibitory Element (TIE), which inhibits general cap-dependent translation, thereby converting a generic mode of mRNA translation into a highly specialized one. Together, these studies uncover a new paradigm of specialized translational regulation that is achieved through a combination of unique RNA regulons to facilitate ribosome-mediate control of gene expression

Parameter control methods for the pumping toolstring composed of perforating gun and fracturing plug in a horizontal well

According to the technological characteristics of the combination perforation and multistage fracturing using drillable bridging plugs, both the hydrodynamics model of wireline sealing system and the mechanical model of toolstring running in the hole were developed. In these models, the equations governing the sealing pressure of grease injection, structure parameters of toostring and pump rate were established. Based on the presented models, the parameter control methods of pumping and their primary influence factors were investigated through case study. For a development well in low-permeability reservoir, the control methods and the reasonable ranges of grease injection sealing pressure, minimum weight and maximum length of toolstring and pump rate were defined using the control equations. The effects of wellhead pressure, hole configuration and running velocity of wireline on parameter controlling were also analyzed. The results show that, with increasing wellhead pressure, the grease injection rate should be increased to improve sealing pressure, and the minimum weight of toolstring should also increase. Increasing the overall angle change rate could lead to a decrease of the maximum allowable length of the toolstring. The pump rate should be adjusted according to the running velocity of wireline. Key words: horizontal well, multistage fracturing, wireline conveyed perforation, toolstring, pump parameter, drillable bridging plug, low-permeability reservoi