Simulation Study of Coal Failure Law under High-Pressure Water Jetting

High-pressure water jetting impinging on coal plays a relatively important role in improving pressure relief and permeability of the coal body, which can elevate the gas drainage effect and eliminate the outburst danger. But the slot formed by high-pressure water jetting impinging on the coal is affected by various factors in pressure relief and permeation of the surrounding coal. To explore how to improve the effect of pressure relief and permeability of the coal body in the process of high-pressure water jetting, the stress-strain and failure of the surrounding coal after the formation of slots were analyzed based on Fast Lagrangian Analysis of Continua 3D(FLAC3D) software, the influence and law exerted from each of the factors was screened out on pressure relief of the slot, and the mathematical model of the slot failure range was constructed. Results show that stress of slots impinged by high-pressure water jetting changes considerably in different directions. As vertical stress increases, the range of pressure relief and failure of the coal body gradually increase, and the pressure relief range enlarges exponentially with the increase of depth. The synergy pressure relief between slots can strengthen the pressure relief of the coal body. The findings obtained from this study can provide construction guidance and reference value for the onsite application of related hydraulic measures

Comparison of left ventricular mechanical dyssynchrony parameters between exercise and adenosine triphosphate stress tests using gated single-photon emission computed tomography myocardial perfusion imaging

Background Left ventricular mechanical dyssynchrony (LVMD) can be induced after stress test. However, no studies have compared the influence of different stress-inducing methods on LVMD parameters. aims The aim of the study was to determine whether there is a difference between exercise and adenosine triphosphate (ATP) stress tests in terms of changes in LVMD parameters assessed using gated single-photon emission computed tomography myocardial perfusion imaging (GSPECT MPI). methods A total of 190 patients who underwent 99mTc-sestamibi GSPECT MPI were consecutively enrolled. Treadmill exercise and ATP stress tests were performed in 95 patients each. Normal myocardial perfusion was defined as the summed stress score (SSS) ≤3 and summed rest score (SRS) ≤3, myocardial ischemia as SSS \u3e3 and SRS ≤3, and myocardial infarction as SSS \u3e3 and SRS \u3e3. Parameters of LVMD, including phase standard deviation (PSD), phase bandwidth (PBW), skewness, and kurtosis were compared. Subtraction was made between values during stress and rest phases to acquire ∆PSD, ∆PBW, ∆skewness, and ∆kurtosis. results There were no differences in LVMD parameters between the exercise and ATP groups. The same results were obtained in the normal perfusion, ischemia, and infarction subgroups. Furthermore, no differences were observed in ∆PSD (median [interquartile range, IQR], 0.25 [-2.3 to 3.1] vs 0.42 (-1.7 to 3.1]; P = 0.73), ∆PBW (median [IQR], 1 [-7 to 11] vs 1 [-6 to 11]; P = 0.95), ∆skewness (mean [SD], -0.06 [0.63] vs 0 [0.81]; P= 0.53), and ∆kurtosis (median [IQR], -0.47 [-4.2 to 4.3] vs -0.42 [-4.8 to 5.2]; P= 0.73) between the exercise and ATP stress-inducing methods. conclusions There are no differences between the exercise and ATP stress tests in terms of changes in LVMD parameters. Thus, the 2 methods can be used alternatively

Myocardial Stunning-Induced Left Ventricular Dyssynchrony On Gated Single-Photon Emission Computed Tomography Myocardial Perfusion Imaging

Objectives Myocardial stunning provides additional nonperfusion markers of coronary artery disease (CAD), especially for severe multivessel CAD. The purpose of this study is to assess the influence of myocardial stunning to the changes of left ventricular mechanical dyssynchrony (LVMD) parameters between stress and rest gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). Patients and methods A total of 113 consecutive patients (88 males and 25 females) who had undergone both stress and rest 99mTc-sestamibi gated SPECT MPI were retrospectively enrolled. Suspected or known patients with CAD were included if they had exercise stress MPI and moderate to severe myocardial ischemia. Segmental scores were summed for the three main coronary arteries according to standard myocardial perfusion territories, and then regional perfusion, wall motion, and wall thickening scores were measured. Myocardial stunning was defined as both ischemia and wall dysfunction within the same coronary artery territory. Patients were divided into the stunning group (n=58) and nonstunning group (n=55). Results There was no significant difference of LVMD parameters between stress and rest in the nonstunning group. In the stunning group, phase SD and phase histogram bandwidth of contraction were significantly larger during stress than during rest (15.05±10.70 vs. 13.23±9.01 and 46.07±34.29 vs. 41.02±32.16, PP\u3c0.05). Conclusion Both systolic and diastolic LVMD parameters deteriorate with myocardial stunning. This kind of change may have incremental values to diagnose CAD

Clinical efficacy analysis of laparoscopic uterine artery pre-ligation combined with hysteroscopic curettage in the treatment of type II cesarean scar pregnancy

ObjectiveTo explore and evaluate the clinical therapeutic effect of laparoscopic uterine artery pre-ligation combined with hysteroscopic curettage in the treatment of type II cesarean scar pregnancy.MethodsThis study analyzed the clinical data of patients with cesarean scar pregnancy (CSP) in the Maternal and Child Health Hospital of Hubei Province from 2018 to 2022. A total of 134 patients with type II cesarean section were enrolled, out of which 78 patients were included in the final analysis. Treatment included either uterine artery embolization (UAE) combined with hysteroscopic curettage (n = 37 patients) or laparoscopic uterine artery pre-ligation (LUAP) combined with hysteroscopic curettage (n = 41 patients). The demographic and clinical characteristics of these two groups were recorded, and their short- and long-term complications on follow-up were compared. For patients with subsequent fertility requirements, we followed up these patients for 2 years after surgery, then collected and analyzed the compared subsequent pregnancy outcome.ResultsWe found no significant discrepancies in the success rate of operation, length of hospital stay, and intraoperative blood loss between the two different operation modes. The cost of LUAP was significantly lower than that of UAE. Furthermore, the incidence of short-term postoperative complications such as fever and pelvic pain was lower in patients treated with LUAP than in those treated with UAE. In terms of long-term postoperative complications, the recovery time for menstruation in the LUAP group (49.81 ± 11.47) was earlier than that in the UAE group (34.90 ± 7.41) (p < 0.05). Additionally, 4.9% of patients in the LUAP group had decreased menstrual flow, while 59% of patients in the UAE group had a marked decrease in menstrual flow, and the incidence and severity of intrauterine adhesions were significantly lower in the LUAP group than in the UAE group(p < 0.05). Consistent with the aforementioned observations, patients treated with LUAP had better postoperative re-pregnancy outcomes than those treated with UAE.ConclusionsBased on the findings, LUAP combined with hysteroscopic curettage is a safe and effective surgical scheme for the treatment of type II CSPs. In addition, compared with UAE, LUAP is associated with a lower surgical cost, fewer short and long-term complications, and better postoperative pregnancy outcomes. Thus, it should be widely applied in patients with type II CSPs

Population genetics of Camellia granthamiana, an endangered plant species with extremely small populations in China

Introduction:Camellia, the largest genus of Theaceae, is well-known for having high economic values. Camellia granthamiana demonstrates large beautiful flowers with some primitive characters, such as multiple large and persistent bracteoles and sepals, was listed as Vulnerable species on the IUCN Red List.Methods: In this study, we investigated all possible records of the species, and sampled four natural populations and five cultivated individuals. By applying shallow-genome sequencing for nine individuals and RAD-seq sequencing for all the sampled 77 individuals, we investigated population genetic diversity and population structure of the species.Results and discussion: The results showed that the population sampled from Fengkai, previously identified as C. albogigias, possessed different plastid genome from other species possibly due to plastid capture; the species possesses strong population structure possibly due to the effect of isolation by distance, habitat fragmentation, and self-crossing tendency of the species, whose effective population size declined quickly in the past 4,000 years. Nevertheless, C. granthamiana maintains a medium level of genetic diversity within population, and significant differentiation was observed among the four investigated populations, it is anticipated that more populations are expected to be found and all these extant populations should be taken into instant protection

Effects of dietary energy level on antioxidant capability, immune function and rectal microbiota in late gestation donkeys

IntroductionThis study investigated the effects of dietary energy level on the antioxidant capability, immune function, and rectal microbiota in donkey jennets during the last 60 days of gestation.MethodsFifteen pregnant DeZhou donkeys with age of 6.0 ± 0.1 years, body weight of 292 ± 33 kg, parity of 2.7 ± 0.1 parities and similar expected date of confinement (74 ± 4 days) were randomly allocated to three groups and feed three diets: high energy (10.92 MJ/kg, H), medium energy (10.49 MJ/kg, M), and low energy (9.94 MJ/kg, L).Results and DiscussionThe serum activity of catalase (CAT), total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC) in group M was significantly higher, whereas the concentrations of malondialdehyde (MDA), interleukin 1 (IL-1), IL-2, and IL-6 were lower than those recorded for groups H and L (p ≤ 0.05). The dietary energy level significantly affected rectal microbial community structure in the jennet donkeys 35 days and 7 days before the parturition (p ≤ 0.05). The abundances of norank_f_norank_o_Coriobacteriales genus was significantly higher (p ≤ 0.05) in group H, and the abundances of norank_f_norank_o_Mollicutes_RF39 and the Candidatus_Saccharimonas were higher in group L (p ≤ 0.05). The abundance of Fibrobacter in group M was significantly increased (p ≤ 0.05). The abundance of norank_f_norank_o_Coriobacteriales was positively correlated with average daily gain (ADG) and tumor necrosis factor-α (TNF-α) concentrations (p ≤ 0.05). The abundance of norank_f_norank_o_Mollicutes_RF39 was positively correlated with IL-2 and IL-6 concentrations. The abundance of Candidatus_Saccharimonas was positively correlated with CAT, T-SOD and GSH-Px activities (p ≤ 0.05). The abundance of Fibrobacter was positively correlated with CAT and T-SOD activities (p ≤ 0.05), but negatively correlated with IL-2 concentration (p ≤ 0.05). In conclusion, an appropriate dietary with an energy content of 10.49 MJ/kg for jennet donkeys during late gestation increased the prenatal antioxidant capacity, reduced inflammatory cytokines, and promoted fetal growth, and these changes were related to diet-induced changes in rectal microbiota compositions

Thermodynamic Stabilities of Perfect and Vacancy-Defected Li2 TiO3 (001) Surfaces From First-Principles Analyses

Lithium titanate (Li2TiO3) is an attractive ceramic material for various industrial applications, particularly as one of the most promising breeder blanket materials in future nuclear-fusion reactors. Previously reported studies mainly focus on sintered polycrystalline samples of Li2TiO3. Surface structure of the single-crystal form is rarely reported, although the information of surface structures and stabilities can be critical for further understanding the surface-associated processes. In this work, we perform extensive first-principles density-functional-theory (DFT) calculations to obtain the surface energies of Li2TiO3 (001) with different surface terminations. For four perfect (defect-free) Li-, O-, or LiTi-terminated (001) surfaces, Li- or O-terminated (001) surfaces can be most stable in limited chemical-potential ranges corresponding to certain experimental conditions, while a LiTi-terminated (001) surface is always unfavorable relative to Li or O terminations. By calculating the total energies of various possible configurations with surface vacancies, we determine the energetically most favorable vacancy-defected surface terminations. From the corresponding ternary phase diagram, we analyze the stability of a specific surface termination with vacancies as well as the possible formation of oxides. Our stability analysis together with DFT-simulated STM images reveals that a 1/3-monolayer-Li-terminated surface most likely corresponds to the ordered hexagonal-like pattern observed previously in STM experiments. For a 1/2-monolayer-Li-terminated surface, the most stable surface structure from our DFT calculations contrasts with previous results from an empirical-potential model