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The solution-treated second-generation single crystal (SX) superalloys underwent hot isostatic pressing (HIP) at 1316 °C and 105 MPa for varying durations. This study investigates the effect of HIP on micropores and stress-rupture behavior under conditions of 980 °C and 250 MPa. The results illustrate that the application of HIP treatment significantly reduces the porosity and volume of micropores, thereby increasing the rupture life of the alloys. With the disappearance of micropores, the crack initiation site shifts from the micropores to the γ/γʹ interface, resulting in reduced crack dimensions and decelerated propagation. Consequently, the smaller size of cracks in HIPed specimens slow down fracture. Nonetheless, the crack propagation pattern remains consistent: cracks expand perpendicular to the stress axis, connecting with cracks at other heights via secondary cracks along the direction.

Current analysis of fragile bronzes mainly relies on the research of two-dimensional aspects such as sample cross-sections and surfaces while typically utilizing optical and electronic microscopy, Raman spectroscopy, and X-ray fluorescence spectroscopy (XRF). As a fast and nondestructive testing method, computer tomography (CT) can be used to characterize and detect the internal structures, corrosion conditions, and corrosion distribution of bronzes. This study used the CT imaging results of fragile bronzes to analyze, locate, and measure corrosion in fragile bronzes quickly and accurately, thus providing strong support for corrosion evaluation and protection research of fragile bronzes. The results verified the value and application prospects of CT technology in the protection of cultural relics.

Objective The different cutting mode of robot‐assisted TKAs may influence the accuracy of alignment. The purpose of this study was to compare alignment accuracy and early clinical outcomes between a CT‐based, saw cutting robotic system (MAKO) and a CT‐free, jig‐guided robotic system (ROSA) for total knee arthroplasty (TKA). Methods A total of 20 MAKO TKAs and 20 ROSA TKAs from June 2021 to June 2022 were retrospectively analyzed. Differences in the postoperative hip‐knee‐ankle (HKA) angle, lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), posterior tibial slope (PTS) and 3° outlier frequency of the HKA, LDFA, MPTA and PTS were studied at 3 months and 1 year of follow‐up. The operative time and total blood loss (TBL) were compared between these two groups. Clinical outcomes at 1 year after surgery, including range of motion (ROM), Western Ontario McMaster University Osteoarthritis Index (WOMAC) score, and Knee Society Score‐2011 (KSS‐2011), were also compared between these two groups. Results The baseline characteristics of the two groups were comparable. There were no significant differences in the mean deviations of postoperative HKA, LDFA, MPTA or PTS between the two groups at 3 months or 1 year (all ps > 0.05). Moreover, there was no significant difference in the percentage of 3° outliers for HKA, LDFA, MPTA, or PTS between the two groups at 3‐month or 1‐year follow‐up (all ps > 0.05). The mean operation time of MAKO was longer than that of ROSA (112.7 ± 12.8 min vs 94.8 ± 23.0 min, p = 0.001), but the mean TBL (1356.7 ± 648.5 mL vs 1384.5 ± 676.3 mL) and transfusion rate (15.0% vs 5.0%) were not significantly different between the two groups (all ps > 0.05). No significant differences were found in postoperative ROM, WOMAC score or KSS score at 1 year (all ps > 0.05). Conclusion The MAKO and ROSA had similar accuracy and precision in TKA alignment. The clinical outcomes at 1 year after surgery were also comparable.

Objectives The reconstruction of bone defects in tibial revision knee arthroplasty is challenging. In this study, we evaluated the primary stability of a novel three‐dimensional (3D)‐printed custom‐made metaphyseal cone for Anderson Orthopedic Research Institute (AORI) IIb or III bone defect reconstruction in tibial revision knee arthroplasty using the combination of finite‐element analysis and biomechanical experiments. Methods In the finite‐element analysis, AORI II b and III medial tibial bone defects were designed at varying depths. A novel 3D‐printed custom‐made metaphyseal cone was designed and used to reconstruct the bone defect with or without a stem in simulated revision total knee arthroplasty (RTKA). A no‐stem group and a stem group were established (based on whether a stem was used or not). Von Mises stress and micromotion were calculated with varying depths of bone defects, ranging from 5 mm to 35 mm, and then micromotions at the bone–implant interface were calculated and compared with the critical value of 150 μm. In the biomechanical experiment, the no‐stem group was used, and the same bone defects were made in four synthetic tibias using patient‐specific instruments. Micromotions at the bone–implant interface were investigated using a non‐contact optical digital image correlation system and compared with the critical value of 150 μm. Results When the bone defect was

Background Primary hyperparathyroidism (PHPT) is an endocrine disorder with high serum calcium and parathyroid hormone (PTH) levels. Excessive secretion of PTH can cause bone loss and may have potential damage to implant fixation after total knee arthroplasty (TKA). However, there is currently no research or literature reporting prosthesis loosening after TKA associated with PHPT. Case presentation This case report describes a TKA failure of tibial prothesis loosening associated with PHPT. The patient faced aggravated pain and difficulty in walking 6 months after the primary TKA. Further examinations showed high serum calcium and PTH levels indicating the presence of PHPT. After the surgery of parathyroidectomy, the patient received revision TKA with 3D‐printed metaphyseal cone. Knee symptoms and function were finally improved. Conclusion PHPT is a risk factor for prosthesis loosening after TKA. Preoperative screening test of serum calcium and PTH levels is important to diagnose PHPT. For patients with PHPT undergoing TKA, preoperative endocrinotherapy and parathyroidectomy are recommended to improve the survival of prosthesis.

Comparable investigation of pore-induced defects during in-phase (IP) and out-of-phase (OP) thermo-mechanical fatigue (TMF) were conducted on fourth-generation single crystal superalloy. It was discovered that recrystallizations and deformation twins would take shape near micro-pores at IP and OP cycling, respectively. High-resolution observation uncovered that the increasing a/6〈112〉 twinning dislocations and more frequent activation of 〈112〉{111} viscous slipping during OP-TMF accounted for twinning nucleation. Atom-scale mapping additionally disclosed the dual effect of Re, Co, and Cr in facilitating twinning formation and impeding of partial dislocations movement. It was deemed that the accumulation of pore-induced twins caused the premature fracture of alloy during OP-TMF.

Abstract Background Knee osteoarthritis (KOA) causes not only pain, stiffness, and dysfunction of the knee, but also the reduction of the joint range of motion (ROM). This study explored the demographic and radiographic factors for knee symptoms and ROM in patients with symptomatic KOA. Methods The demographic variables, Kellgren-Lawrence (KL) grade, and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) of patients with symptomatic KOA recruited in Beijing were collected. The knee ROM of all patients were also measured. We analyzed the influencing factors for WOMAC and ROM using a generalize linear model, respectively. Results This study included a total of 2034 patients with symptomatic KOA, including 530 males (26.1%) and 1504 females (73.0%), with a mean age of 59.17 (± 10.22) years. Patients with advanced age, overweight or obesity, a family history of KOA, a moderate-to-heavy manual labor job and use of nonsteroidal anti-inflammatory drugs (NSAIDs) had significantly higher WOMAC and lower ROM (all P

In recent years, the use of zinc (Zn) alloys as degradable metal materials has attracted considerable attention in the field of biomedical bone implant materials. This study investigates the fabrication of porous scaffolds using a Zn-1Mg-0.1Sr alloy through a three-dimensional (3D) printing technique, selective laser melting (SLM). The results showed that the porous Zn-1Mg-0.1Sr alloy scaffold featured a microporous structure and exhibited a compressive strength (CS) of 33.71 ± 2.51 MPa, a yield strength (YS) of 27.88 ± 1.58 MPa, and an elastic modulus (E) of 2.3 ± 0.8 GPa. During the immersion experiments, the immersion solution showed a concentration of 2.14 ± 0.82 mg/L for Zn2+ and 0.34 ± 0.14 mg/L for Sr2+, with an average pH of 7.61 ± 0.09. The porous Zn-1Mg-0.1Sr alloy demonstrated a weight loss of 12.82 ± 0.55% and a corrosion degradation rate of 0.36 ± 0.01 mm/year in 14 days. The Cell Counting Kit-8 (CCK-8) assay was used to check the viability of the cells. The results showed that the 10% and 20% extracts significantly increased the activity of osteoblast precursor cells (MC3T3-E1), with a cytotoxicity grade of 0, which indicates safety and non-toxicity. In summary, the porous Zn-1Mg-0.1Sr alloy scaffold exhibits outstanding mechanical properties, an appropriate degradation rate, and favorable biosafety, making it an ideal candidate for degradable metal bone implants.

Objective To review the clinical outcomes of revision total knee arthroplasty (RTKA) with massive proximal tibial bone defects using patient‐customized three‐dimensional (3D) printed highly porous metaphyseal cones. Methods A retrospective study of all patients at our institution who underwent RTKA with the Anderson Orthopaedic Research Institute type III tibial defects using patient‐customized 3D‐printed highly porous metaphyseal cones was performed from 2016 to 2018. Seven patients were enrolled in this study. General results (age, sex, and body mass index); intraoperative results (interface compatibility and stability, and operating time); and perioperative complications (total blood loss, blood transfusion rate, and deep venous thrombosis) were recorded and analyzed. Clinical improvement and functional evaluation (survivorship of implant, improvement of Hospital for Special Surgery Score and McMaster Universities Osteoarthritis Index, and improvement of range of motion [ROM]), and radiographic improvement and implant evaluation (progressive radiolucent lines or radiographic loosening, and mechanical alignment) were evaluated at 2 weeks, 6 weeks, 3 months, 6 months, 1 year, 2 years, and then annually, postoperatively. Results The mean age at diagnosis was 68 (61–77) years. The mean follow‐up was 25.3 (19–36) months. At the latest follow‐up, no aseptic loosening, prosthetic joint infection, or other complications were noted. The mean Hospital for Special Surgery Score increased from 49 (39–63) to 78 (70–83) (P

The impact of a Pt-Al bond coat on the high-cycle fatigue (HCF) behaviour of fourth-generation single crystal superalloys at 760℃ and 900℃ was investigated. The Pt-Al bond coat was found to be almost negligible under low stresses at 760℃; however, the bond coat effect was detrimental at 900℃ or under high stresses at 760℃. At 760 °C with increasing high-amplitude stress, the tip cracks preferentially nucleated from defects within coat and propagated inwards, accelerating the fracture. The fatigue life of the coated alloys was considerably decreased at 900 °C, which was attributed to the damage accumulated in the bond coating via oxidation, crack-induced oxide cracking and interfacial microstructure degradation. An Elevated temperature led to the crack-induced oxides shifting from a small fan-shape to a large umbrella-shape, increasing the density of slip bands and quantity of secondary cracks in the substrate. Furthermore, more Ru diffused outwards at 900℃ than that at 760℃, which caused the disappearance of L-C dislocation locks and tertiary γ′ phases and aggravated TCP phases precipitation in the substrate at 900℃. Ultimately, to assess the degradation of the HCF life, an empirical life prediction method was developed, and the calculations results well matched the test results.

Deep vein thrombosis (DVT) is a common postoperative complication of knee/hip arthroplasty. There is a continued need for artificial intelligence-based methods of predicting lower extremity DVT risk after knee/hip arthroplasty. In this study, we performed a retrospective study to analyse the data from patients who underwent primary knee/hip arthroplasty between January 2017 and December 2021 with postoperative bilateral lower extremity venous ultrasonography. Patients’ features were extracted from electronic health records (EHRs) and assigned to the training (80%) and test (20%) datasets using six models: eXtreme gradient boosting, random forest, support vector machines, logistic regression, ensemble, and backpropagation neural network. The Caprini score was calculated according to the Caprini score measurement scale, and the corresponding optimal cut-off Caprini score was calculated according to the largest Youden index. In total, 6897 cases of knee/hip arthroplasty were included (average age, 65.5 ± 8.9 years; 1702 men), among which 1161 (16.8%) were positive and 5736 (83.2%) were negative for deep vein thrombosis. Among the six models, the ensemble model had the highest area under the curve [0.9206 (0.8956, 0.9364)], with a sensitivity, specificity, positive predictive value, negative predictive value, and F1 score of 0.8027, 0.9059, 0.6100, 0.9573 and 0.7003, respectively. The corresponding optimal cut-off Caprini score was 10, with an area under the curve, sensitivity, specificity, positive predictive value, and negative predictive values of 0.5703, 0.8915, 0.2491, 0.1937, 0.9191, and 0.3183, respectively. In conclusion, machine learning models based on EHRs can help predict the risk of deep vein thrombosis after knee/hip arthroplasty.

Circular RNAs (circRNAs) are covalently closed RNA molecules that play important regulatory roles in various tumors. Prostate cancer (PCa) is one of the most common malignant tumors in the world, with high morbidity and mortality. In recent years, more and more circRNAs have been found to be abnormally expressed and involved in the occurrence and development of PCa, including cell proliferation, apoptosis, invasion, migration, metastasis, chemotherapy resistance, and radiotherapy resistance. Most of the circRNAs regulate biological behaviors of cancer through a competitive endogenous RNA (ceRNA) regulatory mechanism, and some can exert their functions by binding to proteins. circRNAs are also associated with many clinicopathological features of PCa, including tumor grade, lymph node metastasis, and distant metastasis. In addition, circRNAs are potential diagnostic and prognostic biomarkers for PCa. Considering their critical regulatory roles in the progression of PCa, circRNAs would be the potential therapeutic targets. In this paper, the current research status of circRNAs in PCa is briefly reviewed.

A novel low-density nickel-based single-crystal superalloy was prepared and the effect of solution treatment on the creep deformation mechanism was systematically investigated. The results reveal that the creep life increases with the increase of solution treatment time, which can be ascribed to microstructural homogenization. However, when the solution treatment time exceeds a threshold limit, the relative proportion of undesirable defects significantly increases, which accelerates the failure and compromises the creep life. The homogenization of the composition leads to the precipitation of a more homogenized γ′ phase and, in turn, results in a more uniform and dense dislocation network, thus hindering the dislocation movement and improving the creep life. The undesirable defects may lead to the stress concentration and weaken the effect of the dislocation network, thus accelerating the creep process and the dislocation are more likely to shear into the γ′ phase. In general, the current study provides guidance for selecting a more reasonable solution treatment time to improve the creep strength.

Deepwater canyon is now the focus of the research field of offshore oil and gas exploration.In the Qiongdongnan Basin of the northwestern South China Sea, several deepwater exploration boreholes have been deployed in the Central Canyon to reveal the lithologic hydrocarbon reservoir of sediment infill therein.However, due to the relatively limited number of these boreholes, the large distance between each borehole, as well as the low resolution of seismic data, the issues regarding the superposition relationship between different sandstone bodies within the canyon, their contact relationship with boundaries, and sedimentary evolution remain poorly understood, which severely hinder the delicate characterization of reservoir physical properties.This study investigates the Lingshui area of the Central Canyon from the perspective of numerical simulation of sedimentation.Geological and mathematical models are established based on the specific geological observations.The hydrodynamic simulation software ANSYS FLUENT is used for the forward modeling of multiple sedimentary stages and sandstone bodies with different initial conditions (e.g., provenance and inlet velocity) to reveal the geometry of modeled turbidite sedimentation, including the horizontal and vertical distribution patterns of sandstone bodies.The simulation results show that: Within the straight section of the canyon, the flow rate and intensity of the turbidity current gradually decrease due to the effect of substrate friction; Relatively coarse and fine particles can be deposited on the substrate and suspended along with the vortex at the head of the turbidity flow, respectively; Within the narrow section of the canyon, the turbulence of the head of the turbidity flow is strong enough to erode the canyon wall and also shift the strike of the canyon.Suspended particles can be affected by centrifugation force to form the overflow sedimentation; In addition, the results show a vertical heterogeneity of sandstone bodies distributed within the canyon: sandstone bodies are usually interlayered by mudstone that features a small thickness and poor lateral continuity.A comparison with the available seismic and borehole data shows the validity of the obtained simulation results.This study attempts to reveal the hydrodynamic processes in terms of different sedimentary stages and sandstone bodies, and then to predict the configuration of sandstone bodies that provides a favorable basis for reservoir prediction.

The internal three-dimensional characteristics of X-ray microtomography (micro-CT) has great application potential in the field of bronze corrosion. This work presents a method of simulating bronze disease based on an in situ micro-CT image to study the characteristics of the oxidative hydrolysis reactions of copper(I) chloride and copper(II) chloride dihydrate. A series of high-resolution reconstruction images were obtained by carrying out micro-CT at three key points throughout the experiment. We found that the reactions of copper(I) chloride and copper(II) chloride dihydrate showed different characteristics at different stages of the simulation in the micro-CT view. The method proposed in this work specifically simulated one single type of bronze corrosion and characterized the evolution characteristics of simulated bronze disease. It provides a new perspective to investigate bronze disease and can help improve the subsequent use of micro-CT to distinguish real bronze corrosions.

The undeveloped low-permeability oil reserves of the Liushagang Formation in the Beibu Gulf Basin are large, but the reservoir quality is poor. The existing classification standards for low-permeability reservoirs cannot meet the needs of fine reservoir evaluation and offshore development.Based on the experiments of constant rate mercury injection, high pressure mercury injection, NMR and seepage mechanism, this paper comprehensively analyzed the micro-pore structure and seepage characteristics, and optimized six kinds of reservoir evaluation parameters: reservoir quality index, fractal dimension of pore structure, mainstream throat radius, mean throat radius, percentage of movable fluid and change rate of threshold pressure gradient, meanwhile, the classification limit of various characterization parameters were determined by integrating with the reservoir quality index, reservoir seepage ability evaluation factors and specific productivity index constraint parameters. A comprehensive evaluation criterion for low-permeability oil reservoirs is established based on the Grey Relational Analysis method, which is divided into Ⅰ, Ⅱa, Ⅱb, Ⅲ and Ⅳ from good to bad.Carried out the grading evaluation of low-permeability reserves and the research results provide a theoretical basis for the analysis of the development potential, the research direction of the low-permeability reserves in Beibu Gulf Basin.The results show: types Ⅰand Ⅱa are relatively high-quality low-permeability reserves and have been put into large-scale development.Types Ⅱb and Ⅲ are extra-low-permeability reserves and are difficult to develop, which need to be formulated for experimental development by reasonable technical measures and development models.

Abstract. Background:. The purpose of this study was to evaluate the clinical outcomes and complications of displaced proximal humeral fractures treated with proximal humeral internal locking system (PHILOS) plate fixation via a deltoid interfascicular (DI) vs a deltopectoral (DP) approach. Methods:. This prospective case-control study was conducted with patients admitted to our hospital from May 2015 to June 2018 who suffered from unilateral displaced proximal humerus fractures. Patients were treated with PHILOS plate fixation via a DI (DI group) or DP approach (DP group). The clinical outcomes and complication data were collected for comparison between the 2 groups. The patients were followed up at 3, 6, and 12 months; and every 6 months thereafter. The patients’ functional recoveries were evaluated according to the normalized Constant-Murley score, range of motion of the shoulder (flexion, abduction, external/internal rotation) and disabilities of the arm, shoulder and hand score. Results:. A total of 77 patients, followed for an average of 15 ± 2.2months (range, 12–21), were enrolled (36 in DI group and 41 in DP group) for final analysis. No significant differences in age, sex, affected side, fracture type, injury mechanism or time from injury to operation were found between the 2 groups (all P > .05). The incision length, intra-operative blood loss, and duration of operation in the DI group were significantly less than those in the DP group, respectively (all P .05). There was no significant difference in the range of shoulder external rotation and abduction during the postoperative follow-ups (P > .05). At the last follow-up, the mean disabilities of the arm, shoulder, and hand score was 14.0 (6.6) points in the DI group and 14.4 (6.9) points in the DP group (P = .793). Complications occurred in 1 patient in the DI group and 8 patients in the DP group (P = .049). Conclusion:. The current study demonstrates that DI approach is a safe and effective alternative for the treatment displaced proximal humerus fractures. The DI approach rather than DP approach was recommended when lateral and posterior exposure of the proximal humerus is required, especially when fixed with PHILOS plate.

Buried hill oil reservoirs have become a key area for offshore oil and gas exploration. In this paper, a typical oil field in the western South China Sea is used as the research object, and a study on the characterization, cause of formation and prediction of the fracture–cavity reservoir distribution is carried out. The reservoir in the study area is a complex fracture–cavity reservoir that developed due to weathering and leaching, tectonic movement and dissolution reconstruction on the limestone skeleton. The reservoir spaces are composed of karst caves, fractures and pores. The main controlling factors include lithological changes, karst landforms, tectonic deformation and faulting. To address the controlling mechanisms of the lithological changes on the formation of fracture–cavity reservoirs, a new parameter, the lithology standard deviation, to evaluate lithological changes is proposed based on the characteristics of the lithological changes, and the distribution of these lithological changes is portrayed in combination with the seismic attributes. The tectonic deformation principal curvature inversion algorithm is used to simulate the distribution of the tectonic principal curvature at the top of the Carboniferous. The larger the tectonic principal curvature is, the stronger the deformation of the rock formation and the more favorable the conditions are for fracture formation. The karst geomorphology controls the overall reservoir distribution, and the karst highlands and karst slope areas are the zones with the most–developed secondary pore space (or fractures and karst caves). The faulting control area is the fracture and dissolution pore development area, major faults control the distribution of the karst cave reservoirs, and secondary faults influence the formation of fractures in the faulted area. The study predicts and evaluates the distribution of fracture–cavity reservoirs from the perspective of fracture–cavity genesis quantification, and by gridding and normalizing the four major genesis quantification evaluation parameters and fusing the geological factors that control the formation of fractures and karst caves by using Back–Propagation neural network deep learning algorithms, a method for predicting the distribution of fracture–cavity reservoirs constrained by geological genesis analysis is developed.

Abstract Background Aseptic cup loosening is still one of the main reasons leading to acetabular cup failures. 3D printing porous trabecular titanium metal acetabular cup may provide good initial stability and secondary fixation because of its highly interconnected, porous structure. Few large sample studies have reported the clinical outcomes of electron beam melting (EBM) porous titanium acetabular cup in Chinese population. Methods We retrospectively collected and analyzed the clinical data of a total of 92 consecutive patients between January 2013 and November 2017, with an average follow-up of 48.2 ± 3.6 months. Clinical outcomes included Harris Hip Score (HHS), the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index, satisfaction rate, and cup survival rate were evaluated. Radiographic assessments were conducted to evaluate osteointegration. Results HHS scores improved significantly while the WOMAC score decreased significantly at the latest follow-up (p < 0.001). The satisfaction rate (prevalence of satisfied or very satisfied) was 91.3%. No acetabular cup failures occurred. Radiolucent lines appeared in 15 cases (18 hips) and disappeared in 6 months. No cup loosening signs found until the last follow-up. The overall survival rate of implantation is 99.1% (cup survival rate 100%). Conclusion The new EBM-produced 3D ACT™ cup demonstrated us its favorable short- to mid-term clinical outcomes in Chinese THA patients. It can provide high acetabular cup survival rate, great clinical improvements and excellent biological fixation. Further investigations are needed to confirm its long-term outcomes.

Abstract Background The role of cystoprostatectomy for the treatment of locally advanced prostate cancer (LAPC) was evaluated by a comprehensive review of contemporary literatures. Methods A systematic search of English language literatures using PubMed, EMBASE, Web of Science, and Cochrane library, from 1990 to 2018, was performed. Two independent authors reviewed abstracts as well as full-text articles and extracted data from the selected manuscripts. Results After the literature research, seven articles with a total of 211 patients were identified. Both 120 cases who received cystoprostatectomy for the primary treatment of LAPC and 91 cases for the salvage surgery after local recurrence were finally included. Overall incidence of positive surgical margins ranged from 25 to 78%. The incidence of major complications caused by the surgery during the follow-up time was limited. It had been reported that among LAPC patients who received cystoprostatectomy combined with adjuvant therapies, 5-year cancer-specific survival rate and 5-year biochemical progression-free survival was up to 87.1% and 62.2%. Moreover, symptoms such as hematuria and other urination dysfunctions, as well as patients’ quality of life were significantly improved after cystoprostatectomy in LAPC patients with the bladder invasion. Conclusions Cystoprostatectomy can serve as an alternative to the surgical step of multimodal therapy for highly selected LAPC patients with the bladder invasion, which may improve patients’ symptoms and related quality of life. Therefore, cystoprostatectomy as an option for the treatment of LAPC with the bladder invasion may be feasible and safe with considerable survival outcomes.

The global mobility theory was used to evaluate the experimental results of oil displacement with water of different salinities. The results of scanning electron microscopy, X diffraction of clay minerals, nonlinear seepage and nuclear magnetic resonance experiments and particle migration inhibition experiments before and after water flooding were compared to determine the mechanisms of water sensitive damage and enhanced water flooding mechanism of low permeability sandy conglomerate reservoirs in Wushi region of Beibuwan Basin, China. A production equation of the oil-water two phase flow well considering low-speed non-Darcy seepage and reservoir stress sensitivity was established to evaluate the effect of changes in reservoir properties and oil-water two-phase seepage capacity on reservoir productivity quantitatively, and injection water source suitable for the low permeability sandy conglomerate reservoirs in Wushi region was selected according to dynamic compatibility experimental results of different types of injected water. The seepage capacity of reservoir is the strongest when the injected water is formation water of 2 times salinity. The water-sensitive damage mechanisms of the reservoirs in Wushi region include hydration of clay minerals and particle migration. By increasing the content of cations (especially K+ and Mg2+) in the injected water, the water-sensitive damage of the reservoir can be effectively inhibited. The formation water of Weizhou Formation can be used as the injection water source of low permeability sandy conglomerate reservoirs in the Wushi region. Key words: Beibuwan Basin, low permeability reservoir, sandy conglomerate reservoir, water-sensitive damage, enhanced water flooding, effective driving coefficient, global mobility, water flooding

Bladder cancer (BCa) is a common heterogeneous urinary system tumor with high malignancy and limited advancement in treatment. Limited understanding of BCa has not contributed to any significant progress in diagnosis or treatment, exploring the mechanisms underlying BCa has become an urgent research focus. Exosomes, a type of extracellular vesicle (EV), have drawn substantial interest for their important roles in mediating intracellular communication. Exosomes shuttle numerous bioactive molecules, and noncoding RNAs (ncRNAs) are among the most numerous. ncRNAs including microRNA, long noncoding RNA, and circular RNA are sorted and packaged into exosomes selectively and transferred into recipient cells to regulate their function. Exosomal ncRNAs are associated with hallmarks of BCa, such as proliferation, apoptosis, epithelial-mesenchymal transition (EMT), cell cycle arrest, lymphangiogenesis, and chemotherapy resistance. Exosomal ncRNAs can also be detected in urine and serum, making them encouraging biomarkers for BCa diagnosis and prognosis. More importantly, exosomes exhibit excellent biocompatibility and potential for diversified applications. The delivery of bioactive substances and drugs into specific cells has become a promising approach for precision therapy for BCa patients. In addition, cancer vaccines have also received increasing attention. In this review, we summarize the current research on the regulatory roles of exosomal ncRNAs in BCa tumorigenesis and progression, as well as their potential clinical value in accelerating the diagnosis and therapy of BCa.

Rice is a staple food for the world’s population. However, the straw produced by rice cultivation is not used sufficiently. Returning rice straw to the field is an effective way to help reduce labor and protect the soil. This study focused on the effect of water-covered depth with the freeze–thaw cycle on rice straw decomposition and the soil fungal community structure in a field in Northeast China. The field and controlled experiments were designed, and the fungal ITS1 region was tested by high-throughput sequencing for analyzing the fungal communities in this study. The results showed that water coverage with the freeze–thaw cycle promoted the decomposition of rice straw and influenced the fungal community structure; by analyzing the network of the fungal communities, it was found that the potential keystone taxa were Penicillium, Talaromyces, Fusarium, and Aspergillus in straw decomposition; and the strains with high beta-glucosidase, carboxymethyl cellulase, laccase, lignin peroxidase, and manganese peroxidase could also be isolated in the treated experiment. Furthermore, plant pathogenic fungi were found to decrease in the water-covered treatment. We hope that our results can help in rice production and straw return in practice.

Based on the extended Huygens–Fresnel principle and the power spectrum of anisotropic oceanic turbulence, the analytical expressions of the average intensity and coherence properties of an off-axis hollow Gaussian-Schell model (OAHGSM) vortex beam propagating through anisotropic oceanic turbulence were derived. The effects of turbulent ocean and beam characteristic parameters on the evolution properties of the OAHGSM vortex beam were analyzed in detail. Our numerical simulation results showed that the OAHGSM vortex beam with a larger position factor is more focusable. Meanwhile, the OAHGSM vortex beam eventually evolves into a Gaussian-like beam after propagating through the anisotropic oceanic turbulent channel. The speed of this process can be accelerated by the decrease of the hollow order, topological charge, beam width, and transverse coherence width of the beam. The results also indicated that the normalized average intensity spreads more greatly and the spectral degree of coherence decays more rapidly for the smaller dissipation rate of the kinetic energy per unit mass of fluid, the smaller anisotropic coefficient, the smaller inner scale factor, the larger dissipation rate of the mean-squared temperature, and the higher temperature–salinity contribution ratio.

Rice straw is a byproduct of agricultural production and an important agricultural resource. However, rice straw has not yet been effectively used, and incorrect treatment methods (such as burning in the field) can cause serious damage to the environment. Studies have shown that straw returning is beneficial to soil, but there have been few studies focused on the effect of the amount of short-term straw returned on the soil microbial community. This study evaluates 0%, 50%, 75%, and 100% rice straw returned to the field on whether returning different amounts of straw in the short term would affect the diversity and composition of the soil microbial community and the correlation between bacteria and fungi. The results show that the amount of straw returned to the field is the main factor that triggers the changes in the abundance and composition of the microbial community in the paddy soil. A small amount of added straw (≤50% straw added) mainly affects the composition of the bacterial community, while a larger amount of added straw (>50% straw added) mainly affects the composition of the fungal community. Returning a large amount of straw increases the microbial abundance related to carbon and iron cycles in the paddy soil, thus promoting the carbon and iron cycle processes to a certain extent. In addition, network analysis shows that returning a large amount of straw also increases the complexity of the microbial network, which may encourage more microbes to be niche-sharing and comprehensively improve the ecological environment of paddy soil. This study may provide some useful guidance for rice straw returning in northeast China.

A productivity analysis for gas-water wells in abnormal overpressure gas reservoirs, considering seepage capability changes of gas-water two phases, elastic drive energy of reservoirs and fluids, physical property changes caused by stress sensitivity of reservoir etc, is proposed, and the influences of various factors on gas production rate are analyzed by practical examples. Based on generalized Darcy formula and the law of conservation of mass, mathematical models of steady-state and unsteady-state seepage considering stress sensitivity of reservoirs and seepage capability changes of gas-water two phases are established, then, corresponding formulas of gas production rate are deduced. Results of practical example analysis show that: the increase of reservoir water content causes decrease of seepage capability of gas phase, and thus declining the gas production rate, so the influence of seepage capability changes of gas-water two phases on gas production rate cannot be ignored in the process of productivity evaluation for gas-water wells; gas production rate has smaller variations with the increase of stress sensitivity when production pressure drop is small, while gas production rate decreases significantly with the increase of stress sensitivity when production pressure drop is large. Therefore, the production pressure drop of gas wells at the beginning of the development should not be too high for gas reservoirs with high stress sensitivity. Key words: water-bearing gas reservoir, abnormal overpressure gas reservoir, stress sensitivity, gas-water two phases, steady-state seepage, unsteady-state seepage, gas well productivity

An amendment to this paper has been published and can be accessed via the original article.

IntroductionMillions of patients are currently suffering from pain and dysfunction caused by osteoarthritis (OA), and billions of dollars have been invested into treatment. Because there is no effective treatment that can reverse the progression of knee OA, it is important to determine the risk factors that may influence the progression. However, although there are many studies that examine risk factors for progression, there are only a few that specifically focus on the impact of each risk factor for predicting progression of knee OA. This study aimed to develop a cohort of patients with primary knee OA in the Beijing area to establish models that identify the influence of each risk factor on the prediction of knee OA progression.Methods and analysisThis is a prospective, multicentre, hospital-based cohort study. The study population comprises 2000 patients with primary knee OA from the Beijing area. The recruitment and baseline visits started in December 2017 and will finish in November 2018. After baseline visits, the patients will be followed for 3 years or until the occurrence of primary outcomes. Demographic variables will be collected during the baseline visit. Influencing factors including occupational exposures, family history and treatment will be collected at baseline and each follow-up visit. The primary outcome measure is a comprehensive index which will be combined with clinical WOMAC score, imaging K-L grade and clinical outcomes. These data will also be collected at baseline and each follow-up visit.Ethics and disseminationThis study protocol has been approved by Peking University Third Hospital Medical Science Research Ethics Committee. All the eligible participants will give written informed consent. The findings will be published in peer-reviewed journals and presented at national or international conferences. Besides, the results will be disseminated to all participants via the social software ‘WeChat’.Trial registration numberChiCTR-ROC-17013790; preresults.

In this paper, we use two methods to research the propagation characteristics of a Hypergeometric-Gaussian (HyGG) vortex beam under oceanic turbulence. One is numerical calculation based on the Rytov approximation theory, where the theoretical detection probability equation of the HyGG vortex beam propagating through oceanic turbulence is derived. The other is numerical simulation based on random phase screens model of oceanic turbulence, where the influences generated by oceanic turbulence on the phase and intensity of the propagation beam as well as the propagation of the beam through several independent phase screens, kept at the same distance, have the same effect. The effects of oceanic turbulence parameters and initial beam parameters on the detection probability of the HyGG vortex beam at the receiver are discussed. The results of theoretical derivation are well in agreement with those of numerical simulation, which demonstrated that the numerical simulation method could effectively simulate the complex theoretical derivation. Both results show that with higher dissipation rate of kinetic energy per unit mass of fluid, smaller dissipation rate of mean-squared temperature and lower temperature-salinity contribution ratio comes the better detection probability. Meanwhile, a HyGG vortex beam with smaller topological charge and longer wavelength has a superior turbulent resistance property. It provides a promising way to estimate the propagation characteristics of the optical beams in an underwater environment.

This study concentrates on several factors which govern the nanoscale plasticity of in situ compressed dislocation-free Ni3Al nanocubes: cube size, aspect ratio and the presence of grooves. The yield strength of dislocation-free Ni3Al nanocubes exhibits an apparent size dependence. The size dependence is strong when cubes are smaller than 300 nm. Compared with the strength of bulk Ni3Al single crystals, the strength of nanocubes is two orders of magnitude higher, which clearly demonstrates that there is a size effect. Nanocube plasticity strongly depends on the alignment and the shape of the cubes. Deformed aligned nanocubes either display only a few localized deformation events (slip lines) or were homogenously compressed into flats due to multiple slip dislocation-mediated plasticity. For an aligned cube, crack initiation at the intersection of a slip line with a groove in the cube surface was observed. In case of a double cube, crack initiation occurs at surface irregularities, while subsequent crack propagation occurs along one or more slip planes.