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Abstract In many applications, there is a need for algorithms that can align partially overlapping point clouds while remaining invariant to corresponding transformations. This research presents a method that achieves these goals by minimizing a binary linear assignment-least squares (BLALS) energy function. First, we reformulate the BLALS problem as the minimization of a quadratic function with quadratic and linear constraints through variable substitution. By utilizing semidefinite relaxation and the convex envelope of bilinear monomials, we relax the problem to create a lower bound that can be solved using linear assignment and low-dimensional semidefinite programming. Additionally, we develop a branch-and-bound (BnB) algorithm that only branches over the transformation variable, which enhances convergence. Experimental results show that, compared to state-of-the-art approaches, the proposed method is robust against non-rigid deformation and outliers when the outliers are separate from the inliers. However, its robustness decreases when outliers are mixed with inliers. The run time of our method is relatively high due to the need to solve a semidefinite program in each iteration of the BnB algorithm.

Abstract Glaucoma is a leading cause of irreversible visual impairment worldwide, characterized by the progressive death of retinal ganglion cells (RGCs). Deubiquitinating enzyme (DUB) inhibitors have shown promise as pharmacological interventions for neurodegenerative disorders. Our study focuses on the pan-DUB inhibitor PR-619 and its potential neuroprotective effects on RGCs through modulation of parkin-mediated mitophagy in experimental glaucoma models. The results show that impaired mitophagy exists in RGCs of our experimental glaucomatous model. In vivo, PR-619 increased RGCs survival in glaucomatous rats. In vitro, it protected RGCs against excitotoxicity and reduced ubiquitin-specific protease (USP) 15 expression. Additionally, PR-619 upregulated parkin expression, increased LC3-II/LC3-I ratios, and elevated LAMP1 levels, indicating enhanced mitophagy in vivo and in vitro. Moreover, numbers of mitophagosomes were increased in optic nerves of PR-619-treated ocular hypertensive rats in vivo. Furthermore, parkin knockdown negated the salutary effects of PR-619 and attenuated expression of parkin-dependent mitophagy effectors in RGCs subjected to glutamate excitotoxicity in vitro. Collectively, these findings implicate augmented parkin-mediated mitophagy as the mechanistic substrate underscoring the neuroprotective capacity of PR-619 in experimental glaucoma. These revelations engender the prospect that pharmacological agents or biotherapeutics augmenting parkin-mediated mitophagy may proffer viable therapeutic modalities for glaucomatous neurodegeneration characterized by impaired mitophagy.

Abstract The current extension limit prediction model for offshore extended-reach well (ERW) in mudstone does not consider the formation collapse, which poses a huge risk to offshore drilling construction. To address this problem, this paper presents new open-hole extension limit prediction model for ERW. By considering formation collapse, rate of penetration (ROP), and annular pressure loss, the extension limit models during normal drilling and tripping were derived. The sensitivity of geological and engineering factors was evaluated by analyzing limits for wells 1H and 2H. The research results showed that: (1) The extension limit increases with the ROP and formation collapse duration, but decreases with the increase in mud weight, plastic viscosity, and flow rate. (2) In ERWs, the mud flow rate has a significant impact on the extension limit than the plastic viscosity of mud fluid. However, mud weight has the least impact compared to the two. (3) Considering various parameters, the predicted extension limit of well 1H, when the mud weight is 1.16 g/cm3 [9.67 ppg], is 1593.28 m [5225.96 ft] less than the limit when the collapse period is not considered.

Abstract Sunspots play a crucial role in both weather forecasting and the monitoring of solar storms. In this work, we propose a novel combined model for sunspot prediction using improved gated recurrent units (GRU) guided by pinball loss for probabilistic forecasts. Specifically, we optimize the GRU parameters using the slime mould algorithm and employ a seasonal-trend decomposition procedure based on loess to tackle challenges related to sequence prediction, such as self-correlations and non-stationarity. To address prediction uncertainty, we replace the traditional $$l_2$$ l 2 -norm loss with pinball loss. This modification extends the conventional GRU-based point forecasting to a probabilistic framework expressed as quantiles. We apply our proposed model to analyze a well-established historical sunspot dataset for both single- and multi-step ahead forecasting. The results demonstrate the effectiveness of our combined model in predicting sunspot values, surpassing the performance of other existing methods.

Abstract To compare the biomechanical properties of several anterior pelvic ring external fixators with two new configurations in the treatment of Tile C pelvic fractures, in order to evaluate the effectiveness of the new configurations and provide a reference for their clinical application. A finite element model of a Tile C pelvic ring injury (unilateral longitudinal sacral fracture and ipsilateral pubic fracture) was constructed. The pelvis was fixed with iliac crest external fixator (IC), anterior inferior iliac spine external fixator (AIIS), combination of IC and AIIS, combination of anterior superior iliac spine external fixator (ASIS) and AIIS, and S1 sacroiliac screw in 5 types of models. The stability indices of the anterior and posterior pelvic rings under vertical longitudinal load, left–right compression load and anterior–posterior shear load were quantified and compared. In the simulated bipedal standing position, the results of the vertical displacement of the midpoint on the upper surface of the sacrum are consistent with the displacement of the posterior rotation angle, and the order from largest to smallest is IC, AIIS, ASIS + AIIS, IC + AIIS and S1 screw. The longitudinal displacement of IC is greater than that of the other models. The displacements of ASIS + AIIS and IC + AIIS are similar and the latter is smaller. In the simulated semi-recumbent position, the vertical displacement and posterior rotation angle displacement of the midpoint on the upper surface of the sacrum are also consistent, ranking from large to small: IC, AIIS, ASIS + AIIS, IC + AIIS and S1 screw. Under the simulated left–right compression load state, the lateral displacements of the highest point of the lateral sacral fracture end are consistent with the highest point of the lateral pubic fracture end, and the order from large to small is S1 screw, IC, AIIS, ASIS + AIIS and IC + AIIS, among which the displacements of S1 screw and IC are larger, and the displacements of ASIS + AIIS and IC + AIIS are similar and smaller than those of other models. The displacements of IC + AIIS are smaller than those of ASIS + AIIS. Under the simulated anterior–posterior shear load condition, the posterior displacements of the highest point of the lateral sacral fracture end and the highest point of the lateral pubic fracture end are also consistent, ranking from large to small: IC, AIIS, ASIS + AIIS, IC + AIIS and S1 screw. Among them, the displacements of IC and AIIS are larger. The displacements of ASIS + AIIS and IC + AIIS are similar and the latter are smaller. For the unstable pelvic injury represented by Tile C pelvic fracture, the biomechanical various stabilities of the combination of IC and AIIS are superior to those of the external fixators of conventional configurations. The biomechanical stabilities of the combination of ASIS and AIIS are also better than those of the external fixators of conventional configurations, and slightly worse than those of the combination of IC and AIIS. Compared with sacroiliac screw and conventional external fixators, the lateral stabilities of IC + AIIS and ASIS + AIIS are particularly prominent.

ObjectiveThe long-term glucose monitoring is essential to the risk assessment of diabetic retinopathy (DR), the aim of this study was to investigate the predictive ability of visit-to-visit fasting blood glucose (FBG) indices on the risk of DR.MethodsThis was a community-based, cohort study conducted from 2013 to 2021. DR was diagnosed by digital fundus photography. The FPG indices included FBG, var. Associations of each FBG indices and DR were estimated using multinomial logistic regression models adjusting for confounders, and discrimination was determined by area under the curve (AUC). Predictive utility of different models was compared by changes in AUC, integrated discrimination improvement (IDI), and net reclassification index (NRI).ResultsThis study analyzed 5054 participants, the mean age was 46.26 ± 11.44 years, and 2620 (51.84%) were women. After adjustment for confounders, the adjusted odds ratios (ORs) with 95% confidence intervals (CIs) for FBG, SD, CV, VIM, ARV, M-FBG, and cumulative FBG load were 1.62 (1.52—1.73), 2.74 (2.38—3.16), 1.78 (1.62—1.95), 1.11 (0.95—1.29), 1.72 (1.56—1.91), 2.15 (1.96—2.36), and 2.57 (2.31—2.85), respectively. The AUC of the model with separate cumulative FBG load and classical risk factors was 0.9135 (95%CI 0.8890—0.9380), and no substantive improvement in discrimination was achieved with the addition of other FBG indices once cumulative FBG load was in the model.ConclusionsCumulative FBG load is adequate for capturing the glucose-related DR risk, and the predictive utility of cumulative FBG load is not significantly improved by adding or replacing other FBG indices in the assessment of DR risk.

Background: Craniopharyngiomas have a high recurrence rate and a poor prognosis, and the key methods for reducing recurrences are unknown. The aim of this study was to explore the key points of microscopic or endoscopic transsphenoidal surgery used to treat infradiaphragmatic craniopharyngiomas. Methods: We reviewed the medical records of patients with infradiaphragmatic craniopharyngiomas who were admitted to Peking Union Medical College Hospital between 2011 and 2018. Results: When considering tumor location, all 34 patients had intrasellar tumors, with 19 of them exhibiting suprasellar extensions. Of the 34 patients, 24 patients underwent resection under the microscope and the remaining 10 patients underwent transsphenoidal endoscopic surgery. Gross total tumor resection was achieved in 16 patients. Twelve patients underwent invaded sellar diaphragm resection, while the remaining 22 patients were not. Cerebrospinal fluid leaks occurred during surgery in 18 patients. Visual acuity improved in two patients. After an average follow-up of 31.1 months, 13 patients experienced tumor recurrence. The short term recurrence rate in the sellar diaphragm resection group was significantly lower compared to the non-resected group (P

Abstract Current treatment for functional dyspepsia (FD) has limited and unsustainable efficacy. Probiotics have the sustainable potential to alleviate FD. This randomized controlled clinical trial (Chinese Clinical Trial Registry, ChiCTR2000041430) assigned 200 FD patients to receive placebo, positive-drug (rabeprazole), or Bifidobacterium animalis subsp. lactis BL-99 (BL-99; low, high doses) for 8-week. The primary outcome was the clinical response rate (CRR) of FD score after 8-week treatment. The secondary outcomes were CRR of FD score at other periods, and PDS, EPS, serum indicators, fecal microbiota and metabolites. The CRR in FD score for the BL-99_high group [45 (90.0%)] was significantly higher than that for placebo [29 (58.0%), p = 0.001], BL-99_low [37 (74.0%), p = 0.044] and positive_control [35 (70.0%), p = 0.017] groups after 8-week treatment. This effect was sustained until 2-week after treatment but disappeared 8-week after treatment. Further metagenomic and metabolomics revealed that BL-99 promoted the accumulation of SCFA-producing microbiota and the increase of SCFA levels in stool and serum, which may account for the increase of serum gastrin level. This study supports the potential use of BL-99 for the treatment of FD.

Objective To investigate the impact of the third lumbar skeletal muscle index (L3-SMI) assessed by CT on the in-hospital severity and short-term prognosis of acute pancreatitis. Methods A total of 224 patients with severe acute pancreatitis admitted to Yantaishan Hospital from January 2021 to June 2022 were selected as the subjects. Based on the in-hospital treatment outcomes, they were divided into a mortality group of 59 cases as well as a survival group of 165 cases. Upon admission, general information such as the Acute Physiology and Chronic Health Evaluation II (APACHE II) score, along with the abdominal CT images of each patient, were analyzed. The L3-SMI was calculated, and the Modified CT Severity Index (MCTSI) and Balthazar CT grade were used to assess the severity of in-hospital complications of acute pancreatitis. The evaluation value of L3-SMI for the prognosis of severe acute pancreatitis was analyzed, as well as the factors influencing the prognosis of severe acute pancreatitis. Results No statistically significant differences in gender, age, BMI, etiology, duration of anti-inflammatory drug use, and proportion of surgical patients between the survival and mortality groups were observed. But the mortality group showed higher proportions of patients with an elevated APACHE II score upon admission, mechanical ventilation, and renal replacement therapy, compared to the survival group, with statistically significant differences (P < 0.001). Furthermore, the mortality group had higher MCTSI scores (6.42 ± 0.69) and Balthazar CT grades (3.78 ± 0.45) than the survival group, with statistically significant differences (P < 0.001). The mortality group also had a lower L3-SMI (39.68 ± 3.25) compared to the survival group (42.71 ± 4.28), with statistically significant differences (P < 0.001). L3-SMI exhibited a negative correlation with MCTSI scores and Balthazar CT grades (r = −0.889, −0.790, P < 0.001). Logistic regression analysis, with mortality of acute pancreatitis patients as the dependent variable and MCTSI scores, Balthazar CT grades, L3-SMI, APACHE II score upon admission, mechanical ventilation, and renal replacement therapy as independent variables, revealed that MCTSI scores and L3-SMI were risk factors for mortality in acute pancreatitis patients (P < 0.001). Logistic regression analysis using the same variables confirmed that all these factors were risk factors for mortality in acute pancreatitis patients. Conclusion This study confirmed that diagnosing muscle depletion using L3-SMI is a valuable radiological parameter for predicting in-hospital severity and short-term prognosis in patients with acute pancreatitis.

The sustained casing pressure (SCP) caused by the sealing failure of cement sheaths has become one of the main threats to the safe and efficient production of high-temperature and high-pressure (HTHP) gas wells. An actual HTHP gas well was used as an example, and the temperature calculation models were established. Then, the temperature–pressure coupling finite element coupling models of casing-cement sheath-formation assembly for the whole well were established, and the factors affecting the integrity were examined. Finally, the maximum production and wellhead annular pressure based on the constraints of cement sheath integrity was analyzed. The results indicate that the natural gas would transfer energy to the wellbore assembly during production; the greater the production, the greater the temperature fluctuation of the cement sheath, which was unbeneficial to the integrity, the radial and tangential stresses of the cement sheath increase and decrease, respectively, with depth. The cement sheath near the ground was at risk of tensile failure, which could result in tangential tensile cracks. The cement sheath near the packer was susceptible to compression failure, resulting in radial compression cracks, reducing production and wellhead annular pressure were beneficial to relieve the stress state. Compared to the production, the wellhead pressure has a greater impact, it is necessary to control the wellhead pressure in a reasonable range to ensure integrity.

Electricity demand forecasting is crucial for practical power system management. However, during the COVID-19 pandemic, the electricity demand system deviated from normal system, which has detrimental bias effect in future forecasts. To overcome this problem, we propose a deep learning framework with a COVID-19 adjustment for electricity demand forecasting. More specifically, we first designed COVID-19 related variables and applied a multiple linear regression model. After eliminating the impact of COVID-19, we employed an efficient deep learning algorithm, long short-term memory multiseasonal net deseasonalized approach, to model residuals from the linear model aforementioned. Finally, we demonstrated the merits of the proposed framework using the electricity demand in Taixing, Jiangsu, China, from May 13, 2018 to August 2, 2021.

Drug-resistant efflux pumps play a crucial role in bacterial antibiotic resistance. In this study, potential efflux pump inhibitors (EPIs) with a diphenylmethane scaffold were screened and evaluated against drug-resistant Escherichia coli. Twenty-four compounds were docked against the drug-binding site of E. coli multidrug transporter AcrB, and 2,2-diphenylethanol (DPE), di-p-tolyl-methanol (DPT), and 4-(benzylphenyl) acetonitrile (BPA) were screened for their highest binding free energy. The modulation assay was further used for EPI evaluation, revealing that DPE, DPT, and BPA could reduce the drug IC50 value in E. coli strains overexpressing AcrB, indicating their modulation activity. Only DPE and BPA enhanced intracellular dye accumulation and inhibited the efflux of ethidium bromide and erythromycin. In addition, DPE and BPA showed an elevated post-antibiotic effect on drug-resistant E. coli, and they did not damage the permeability of the bacterial outer membrane. The cell toxicity test showed that DPE and BPA had limited human-cell toxicity. Therefore, DPE and BPA demonstrate efflux pump inhibitory activity, and they should be further explored as potential enhancers to improve the effectiveness of existing antibiotics against drug-resistant E. coli.

To extend the network life, an ordinal potential game is introduced into network topology control, and a network topology control algorithm based on the Theil entropy measure is designed by improving the revenue function. The revenue function is based on the Theil entropy measure, whose factors are in the residual energy of the nodes and their neighbors. By using a primary payoff function that considers all initial network factors and a secondary one that addresses connectivity in case of reduced residual energy, a segmentation function can calculate the model's payoff. Simulation experiments show that compared to the existing game algorithms of 3DK-RNG, DEBA, and EFPC, the proposed algorithm can effectively eliminate redundant links, reduce node degree and network link length, balance node energy consumption, enhance network load, and extend the network life cycle. • A Network Topology Control Algorithm Based on the Fusion of Thiel Entropy and Ordinal Potential Games. • A network topology control method for extending the network lifecycle is successfully established. • It proposes that the performance of the fusion topology control algorithm is significantly superior to other single algorithms in the paper.

IntroductionPediatric pituitary neuroendocrine tumor is a rare condition, and despite previous research focusing on this specific group, the main factors influencing the surgical cure rate have not been identified.MethodsWe conducted a single-center retrospective study on pediatric pituitary neuroendocrine tumor patients who visited Peking Union Medical College Hospital between 2010 and 2023. We collected data on their clinical characteristics, imaging features, surgical outcomes, and follow-up information. Additionally, we used multiple-factor logistic regression to investigate the factors affecting the surgical cure rate of pediatric pituitary neuroendocrine tumor.Results232 patients were diagnosed with pediatric pituitary neuroendocrine tumors, with a higher incidence in females. The most common type was ACTH-secreting adenoma (90/232), followed by prolactin-secreting adenoma (63/232), and growth hormone-secreting adenoma (41/232). The majority of pediatric adenomas were macroadenomas (139/232), and some tumors were associated with cystic changes or hemorrhage (58/232), while a few exhibited invasion of the cavernous sinus (33/232). The results of the multivariate analysis indicated that the different hormone secretion types, macroadenoma or the presence of cystic changes or hemorrhage were not significant risk factors for the cure rate after the first surgery. However, the invasion of the cavernous sinus was found to be an important factor influencing the postoperative cure rate. Most pediatric pituitary neuroendocrine tumors with cavernous sinus invasion were macroadenomas, and some displayed characteristics of refractory pituitary neuroendocrine tumors, with some patients experiencing irreversible complications after surgery.ConclusionPediatric pituitary neuroendocrine tumors are complex, and the postoperative cure rate is particularly poor for tumors with cavernous sinus invasion. Although macroadenoma itself does not significantly impact the postoperative cure rate, it is still recommended to diagnose and treat early to avoid unnecessary surgery or surgical complications.

PurposeTo investigate the prevalence of low blood testosterone level (LTL) and its determinant factors among active male acromegaly patients, as well as the effect of surgery on LTL in male acromegaly patients.MethodsA retrospective, single-center study focused on 252 male acromegaly patients aged 18 years–60 years diagnosed in the Peking Union Medical College Hospital from January 2015 to December 2018 was carried out. The measurements of preoperative and postoperative testosterone levels, serum growth hormone (GH), insulin-like growth factor 1 (IGF-1), and other clinical data were analyzed.ResultsForty per cent of subjects included were diagnosed with LTL pre surgery. Patients were divided into normal testosterone level (NTL) and LTL groups based on their testosterone level. There were significant differences (p < 0.01) between groups in the presence of macroadenomas, invasion of the cavernous sinus, compression of the optic chiasm, and serum GH and prolactin levels pre surgery. Invasion of the cavernous sinus [odds ratio (OR) = 4.299; p = 0.000] and serum prolactin level (OR = 1.023, p = 0.001) were independent predictors of LTLs in male patients before surgical intervention. A total of 67.9% of LTL patients recovered during the follow-up, with a new-onset rate of 3.4%. Body mass index, invasion of the cavernous sinus, GH, IGF-1, and prolactin levels, the presence of a prolactin-secreting tumor, and recovery from acromegaly were significantly different (p < 0.05) in the NTL group and in the LTL group during the follow-up. The presence of a prolactin-secreting tumor (OR = 0.224; p = 0.001) and recovery from acromegaly (OR = 0.168; p = 0.006) were independent predictors of LTLs in male acromegaly patients during the follow-up.ConclusionThe invasiveness of tumor and levels of blood prolactin are independent factors for LTLs before surgery, whereas GH and IGF-1 levels are not. Most male patients can recover from LTL after tumor restriction surgery: those who recover from acromegaly have a better chance of recovering from LTL.

Abstract Background Studies have shown that probiotics have an effect on reducing body fat on a strain-specific and dose–response bases. The purpose of this study was to evaluate the effect of a novel probiotic strain Lacticaseibacillus paracasei K56 on body fat and metabolic biomarkers in adult individuals with obesity. Methods 74 adult subjects with obesity (body mass index ≥ 30 kg/m2, or percent body fat > 25% for men, percent body fat > 30% for women) were randomized into 5 groups and supplemented with different doses of K56 (groups VL_K56, L_K56, H_K56, and VH_K56: K56 capsules, 2 × 107 CFU/day, 2 × 109 CFU/day, 2 × 1010 CFU/day, 2 × 1011 CFU/day, respectively) or placebo (group Pla: placebo capsule) for 60 days. Subjects were advised to maintain their original dietary intake and physical activity. Anthropometric measurements, body composition assessment, and metabolic parameters were measured at baseline and after 60 days of intervention. Results The results showed that the L_K56 group had significant decreases in percent body fat (p = 0.004), visceral fat area (p = 0.0007), total body fat mass (p = 0.018), trunk body fat mass (p = 0.003), waist circumference (p = 0.003), glycosylated hemoglobin(p = 0.002) at the end of the study compared with baseline. There were non-significant reductions in Body weight and BMI in the L_K56, H_K56, VL_K56 groups, whereas increases were observed in the placebo and VH_K56 groups compared with baseline values. In addition, K56 supplementation modulated gut microbiota characteristics and diversity indices in the L-K56 group. However, mean changes in body fat mass, visceral fat area, weight, body mass index, waist circumference and hip circumference were not significantly different between groups. Conclusions The results suggest that supplementation with different doses of Lacticaseibacillus paracasei K56 has certain effect on reducing body fat and glycosylated hemoglobin, especially at a dose of 109 CFU/day. Trial registration: clinicaltrials.gov Identifier: NCT04980599.

The precise segmentation of the glomerular basement membrane (GBM) can aid pathologists in making accurate pathological diagnoses. However, conventional methods solely focus on segmenting GBM from the background, disregarding the interconnections between GBM and its similar surrounding tissues, which leads to imprecise boundary segmentation of GBM. To address this issue, we employed a multi-category segmentation method to model the distinctions and interconnections between GBM and its similar surrounding tissues. Our experimental results demonstrate that this method can more accurately segment GBM with blurred boundaries. Historically, scholars have primarily used convolution to build models. This approach has limitation that only local information is modeled without effectively extracting global information. To address this issue, we propose a more reasonable structure combining convolution and attention, which we call the Self-Reinforcing Attention Mechanism. Experimental results indicate that the addition of the attention mechanism can help the segmentation of GBM by yielding more continuous boundaries. Finally, we incorporate the feature maps of each layer of the model in the loss function, allowing the model to focus semantic information at varying scales while also providing control over the model’s focus by adjusting the weight. Our experimental results demonstrated that the proposed method has higher performance and better generalization ability than the state-of-the-art approaches.

Abstract Objective To compare the breakage risk of lengthened sacroiliac screws and ordinary sacroiliac screws to treat unilateral vertical sacral fractures and provide a reference for clinical application. Methods A finite element model of Tile C pelvic ring injury (unilateral type Denis II fracture of the sacrum) was produced. The sacral fractures were fixed with a lengthened sacroiliac screw and ordinary sacroiliac screw in 6 types of models. The maximal von Mises stresses and stress distributions of the two kinds of screws when standing on both feet were measured and compared. Results The maximal von Mises stress of the lengthened screw was less than that of the ordinary screw. Compared with ordinary screw, the stress distribution in the lengthened screw was more homogeneous. Conclusions The breakage risk of screws fixed in double segments is lower than that of screws fixed in single segments, the breakage risk of lengthened screws is lower than that of ordinary screws, and the breakage risk of screws fixed in S2 segments is lower than that of screws fixed in S1 segments.

Casing is inevitably damaged during perforation operation, and the perforation parameters will have a significant impact on the degree of casing damage, which will directly affect the stability of casing structure in the process of hydraulic fracturing. A three-dimensional numerical model, which was composed of perforating charge, casing–cement sheath, and formation and consistent with the engineering practice, was established, considering the dynamic characteristics of materials in the process of explosion impact. The numerical simulation results were verified by physical model tests and showed that the stress superposition between adjacent perforations increases the damage degree of casing. Perforation density and phase angle directly affect the range of stress superposition area, with the increase of perforation density or decrease of phase angle, the damage area and damage coefficient of casing are increasing. Based on the results of numerical simulation, an innovative perforation parameter optimization method considering casing yield strength was proposed, which could effectively reduce the stress superposition area between adjacent perforations and keep casing damage within a reasonable range. Finally, perforation parameter optimization based on real wells was carried out, and analysis results showed that the casing stress was lower than the yield strength after parameter optimization, which could ensure the stability of the casing. The research results can provide an important reference for the optimization of perforation design and field operation.

The borehole breathing observed when drilling into natural fractured formations is often erroneously identified as leakage or kick. The main reason for this phenomenon is that the fractures around the well have opened and closed after being affected by the wellbore pressure fluctuations. In this paper, a three-dimensional geological model is established for simulating fractured borehole breathing based on the Cohesive unit method, and the full three-dimensional simulation of fractured borehole breathing is realized for the first time. Based on this model, this paper studies the dynamic response characteristics of the fractured borehole breathing mechanism in detail, and analyzes a variety of parameters that may affect borehole breathing. The research results show that: increasing the viscosity of drilling fluid can effectively inhibit the occurrence of borehole breathing and extend its duration; formation elastic modulus is inversely correlated with borehole breathing; borehole breathing is not sensitive to changes in formation Poisson’s ratio and porosity; horizontal geostress affects the severity of borehole breathing by determining the reopening pressure of the fracture; changes in the original width of the fracture will not affect the total volume of backflow, but will affect the amount of mud lost in the early stage.

Casing shear deformation caused by fault slip is a serious problem that restricts shale gas development. As yet, there is no effective method for controlling casing shear deformation. In this study, a cement sheath with hollow glass microspheres was used to prevent and mitigate casing deformation caused by a fault slip. An equivalent outer-diameter model was established. This model analyzes the mechanism by which casing shear deformation is controlled by a cement sheath with hollow glass microspheres under the condition of fault slip. The hollow glass microspheres in the cement sheath were broken owing to the strong shear forces of the fault slip. The internal volume of the hollow glass microspheres was released, which reduced the distance of the fault slip across the casing. The casing deformation was prevented or slowed down. A 3D assembly numerical model was established to evaluate the control effect of the hollow glass microspheres on casing shear deformation. Furthermore, the influences of slip distance, casing thickness, mechanical parameters of formation, mechanical parameters of the cement sheath, and crustal stress difference were analyzed. The mathematical calculation results showed that casing deformation increased with an increase in the fault slip distance, an increase in the stratum elastic modulus, and a decrease in the in situ stress difference. Therefore, the mass content of the hollow glass microspheres in the cement sheath also needs to be increased to ensure that the casing does not deform. The numerical analysis results showed that the change in casing thickness, Poisson’s ratio of formation, and mechanical parameters of the cement sheath had little effect on the mass content of hollow glass microspheres. Finally, the model was used to analyze the test wells in the Weirong Block, Sichuan, China. The calculation results showed that under the same condition of casing deformation of 8.23 mm in adjacent wells, casing shear deformation could be avoided by using a cement sheath with 11.9% hollow glass microspheres in the test well. This study provides a theoretical basis and reference for controlling the casing shear deformation caused by fault slip in shale gas wells.

This study compared the anti-inflammatory properties of Lactobacillus paracasei 6–1 lipoteichoic acid (LTA) obtained via different heat treatments to clarify the effect of heat intensity on its immunomodulatory activity. LTA exposed to low-temperature pasteurization (65 °C for 30 min) contained more acetylglucosamine and exhibited the strongest anti-inflammatory activity. It significantly down-regulated the pro-inflammatory cytokine levels (tumor necrosis factor-alpha (TNF-α), IL-1, IL-6, and IL-12) and increased that of the IL-10 anti-inflammatory cytokine (p

In general, wireless relays are used for connecting wireless communication links, but relays can bring security and deployment issues. This paper investigates the performance of air-to-water communication systems without relay nodes. The probability density function (PDF) of the RF link is obtained by unifying α−μ, the extended generalized -K (EGK) and Fisher Snedecor (ℱ) distributions of atmospheric turbulence. We obtained the joint PDF of the RF/UWOC system for atmospheric turbulence and ocean turbulence with nonzero mean single-sided pointing error as well as air–water interface under foggy conditions. Based on statistical results, exact expressions for outage probability (OP), bit error rate (BER), and channel capacity (CC) were derived. Finally, we validated the analytical expression using Monte Carlo simulation. The simulation results show that the fading parameters of the channel have a significant impact on the performance of a without-relay-assisted RF/UWOC system.

Mosquito transmission of dengue viruses to humans starts with infection of skin resident cells at the biting site. There is great interest in identifying transmission-enhancing factors in mosquito saliva in order to counteract them. Here we report the discovery of high levels of the anti-immune subgenomic flaviviral RNA (sfRNA) in dengue virus 2-infected mosquito saliva. We established that sfRNA is present in saliva using three different methods: northern blot, RT-qPCR and RNA sequencing. We next show that salivary sfRNA is protected in detergent-sensitive compartments, likely extracellular vesicles. In support of this hypothesis, we visualized viral RNAs in vesicles in mosquito saliva and noted a marked enrichment of signal from 3'UTR sequences, which is consistent with the presence of sfRNA. Furthermore, we show that incubation with mosquito saliva containing higher sfRNA levels results in higher virus infectivity in a human hepatoma cell line and human primary dermal fibroblasts. Transfection of 3'UTR RNA prior to DENV2 infection inhibited type I and III interferon induction and signaling, and enhanced viral replication. Therefore, we posit that sfRNA present in salivary extracellular vesicles is delivered to cells at the biting site to inhibit innate immunity and enhance dengue virus transmission.

Underground in situ pyrolysis for oil shale extraction is currently significant; the evolutions in microstructure, porosity, and permeability parameters are essential factors in evaluating the productivity of oil shale after pyrolysis. With the underground oil shale reservoir core, obtained from Jimsar Sag in the Junggar Basin in China, as the research object, the samples were subjected to the treatment at different high temperatures (400°C, 500°C, 600°C, and 700°C). The NMR and FE-SEM experiments on oil shale samples were conducted; the T2 relaxation spectra, pore size distribution, and porosity and permeability variation were analyzed; and the relationships between movable fluid saturation and porosity and permeability were established, respectively. The results showed that when the thermal treatment temperature increased, the porosity and permeability of oil shale rose continuously but showed different laws. With the temperature being lower than 400°C, the porosity increased slowly, and the growth rate of porosity increased rapidly when the thermal treatment temperature was higher than 500°C. In the pyrolysis temperature range of 25°C~400°C, the growth rate of permeability was relatively slow. With the continuously enhancing temperature (500°C~600°C), the growth rate of permeability accelerated rapidly. When the temperature continued to rise (700°C), the increase of permeability began to slow down. There is a nonlinear correlation between porosity and movable fluid saturation and an approximately linear correlation between permeability and movable fluid saturation. The findings showed that 600°C was the suitable temperature for the pyrolysis of oil shale.

Abstract Compound percussive drilling technology is a new method to improve the rock‐breaking efficiency in deep hard formation. In order to study the rock‐breaking mechanism of compound impact drilling, the thermal‐structure coupling simulation of the dynamic rock‐breaking process with a single PDC cutter was investigated by using ABAQUS software. The influence of impact parameters on the rock‐breaking performance and cutting temperature was analyzed. The results proved that the compound impact load changes the rock failure mode and improves the rock‐breaking efficiency. Compared with steady load cutting, the rock broken volume under compound impact increased by 7.5%, and the mechanical specific energy (MSE) decreased by 12.3%. As the axial impact load amplitude increases, the MSE increases gradually. With an increase in torsional impact load amplitude and impact frequency, the MSE decreases first and then increases, and the optimal torsional static load ratio is 0.3, and the optimal impact frequency is 30 Hz. In addition, the cutting temperature of the compound percussive drilling is higher than that of the steady load cutting, and it increases with the impact load amplitude and decreases with the frequency. For the three impact load waveforms—sine, triangle, and square in this paper, the rock‐breaking efficiency under the condition of sine waveform is the largest when the dynamic amplitude of the pulse force is fixed, and the cutting temperature under the condition of square waveform is the highest. Finally, based on the analysis of the rock‐breaking mechanism, a novel compound percussive drilling tool was designed and tested in the field.

Improving the rock-breaking efficiency of hard rock formation has always been of concern in drilling. Compound impact drilling technology is a new method to achieve efficient crushing of hard rock by exerting axial and torsional impacts on the drilling bit. In this study, to investigate the dynamic rock-breaking process and mechanism under compound impact, a numerical model was developed based on cohesive elements. Dynamic impact tests on sandstone were conducted to verify the effectiveness of the method. Then, the dynamic rock-breaking process under compound impact was simulated using the proposed model. Finally, the effects of impact parameters and cyclic loading on the rock-breaking performance were systematically studied. The results indicate that the stereoscopic crushing effect of rock can be achieved under compound impact. The amount of broken rock increases with the increase in the impact load amplitude and impact loading times, whereas both the impact angle and duration have an optimal range. When the impact angle is 30°, the impact duration is 2.5 ms, the amount of broken rock is maximum. A novel compound impact drilling tool was designed based on the analysis of the rock-breaking mechanism, the laboratory and field tests were carried out and the parameters were optimized.