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IntroductionIn the course of immune development, HIV-exposed uninfected (HEU) infants exhibit abnormal immune function and increased infectious morbidity compared to HIV-unexposed uninfected (HUU) infants. Yet the specific functional phenotypes and regulatory mechanisms associated with in-utero HIV and/or ART exposure remain largely obscure.MethodsWe utilized flow cytometry and RNA-seq technologies to conduct the immunological and transcriptomic profiling in cord blood from 9 HEU mother-infant pairs and 24 HUU pairs. On top of that, we compared the cord blood dataset with the maternal venous blood dataset to characterize unique effects induced by in-utero HIV and/or ART exposure.ResultsFlow cytometry immunophenotyping revealed that the level of B lymphocyte subsets was significantly decreased in HEU cord blood as compared to HUU (P < 0.001). Expression profiling-based cell abundance assessment, includes CIBERSORT and ssGSEA algorithm, showed a significantly reduced abundance of naive B cells in HEU cord blood (both P < 0.05), supporting the altered composition of B lymphocyte subsets in HEU. Functional enrichment analysis demonstrated suppressed innate immune responses and impaired immune regulatory function of B cells in HEU cord blood. Furthermore, through differential expression analysis, co-expression network analysis using WGCNA, and feature selection analysis using LASSO, we identified a 4-gene signature associated with HEU status. This signature effectively assesses B cell levels in cord blood, enabling discrimination between HEU and HUU infants.DiscussionOur study provides the first comprehensive immunological and transcriptomic characterization of HEU cord blood. Additionally, we establish a 4-gene-based classifier that holds potential for predict immunological abnormalities in HEU infants.

Abstract Background It’s difficult to treat segmental tibial fractures (STFs), which are intricate injuries associated with significant soft tissue damage. The aim of this study was to compare the clinical effect of hexaxial external fixator (HEF) and intramedullary nail (IMN) in treatment of STFs. Methods A total of 42 patients with STFs were finally recruited between January 2018 and June 2022. There were 25 males and 17 females with age range of 20 to 60 years. All fractures were classified as type 42C2 using the Arbeitsgemeinschaftfür Osteosythese/Orthopaedic Trauma Association (AO/OTA) classification. 22 patients were treated with HEF and 20 patients were treated with IMN. The condition of vascular and neural injuries, time of full weight bearing, bone union time and infection rate were documented and analyzed between the two groups. The mechanical medial proximal tibial angle (mMPTA), mechanical posterior proximal tibial angle (mPPTA), mechanical lateral distal tibial angle (mLDTA), mechanical anterior distal tibial angle (mADTA), hospital for special surgery (HSS) knee joint score, American Orthopaedic Foot and Ankle Society (AOFAS) ankle joint score, range of motion (ROM) of flexion of keen joint and ROM of plantar flexion and dorsal flexion of ankle joint were compared between the two groups at the last clinical visit. Results There were no vascular and neural injuries or other severe complications in both groups. All 22 patients in HEF group underwent closed reduction but 3 patients in IMN group were treated by open reduction. The time of full weight bearing was (11.3 ± 3.2) days in HEF group and (67.8 ± 5.8) days in IMN group(P 0.05). The ROM of dorsal flexion of ankle joint in IMN group was (30.4 ± 3.5)°, better than (21.6 ± 2.8)° in HEF group (P

Abstract Background Stress hyperglycemia ratio (SHR), associated with adverse outcomes in patients with ST-segment elevation myocardial infarction (STEMI), has several definitions. This study aims to assess the prognostic value of SHR, derived from hemoglobin A1c (HbA1c) or glycated albumin (GA), to mortality. Methods The study comprised 1,643 STEMI patients who underwent percutaneous coronary intervention (PCI) in two centers. SHR1 was calculated using fasting blood glucose (FBG)/GA, while SHR2 was calculated using the formula FBG/(1.59*HbA1c-2.59). The primary endpoints were in-hospital death and all-cause mortality, with a median follow-up duration of 1.56 years. Results Higher SHR1 and SHR2 values are associated with increased risks of in-hospital death and all-cause mortality. Each standard deviation increase in SHR1 corresponded to a 39% and 22% escalation in in-hospital death and all-cause mortality, respectively. The respective increases for SHR2 were 51% and 26%. Further examinations validated these relationships as linear. Additionally, the areas under the curve (AUC) for in-hospital death were not significantly different between SHR1 and SHR2 (p > 0.05). Incorporating SHR1 or SHR2 into the base model significantly improved the discrimination and risk reclassification for in-hospital and all-cause mortality. A subgroup analysis revealed that the effects of SHR1 and SHR2 were more pronounced in patients with hypercholesteremia. Conclusion SHR1 and SHR2 have emerged as robust and independent prognostic markers for STEMI patients undergoing PCI. The SHR calculation based on either HbA1c or GA can provide additional predictive value for mortality beyond traditional risk factors, helping to identify high-risk STEMI patients.

Shrub species Caragana korshinskii Kom. dominates slope protection and soil and water conservation in the loess area of the northeastern Qinghai–Tibet Plateau. However, the root anchoring mechanism and the effects of soil consolidation and slope protection of this shrub species remain unclear. This study aimed to elucidate the anchoring mechanism of roots of the C. korshinskii roots and establish a calculation model to evaluate their contribution to the stability of shallow loess slopes. C. korshinskii plants with an 11-year growth period were selected as the study subject. The anchoring force of C. korshinskii roots was determined through in-situ excavation tests, in-situ root pullout tests, and theoretical analysis, along with their impact on the stability of shallow loess soil slopes. The results showed that, due to the absence of a “bolt head” structure on the root surface, it was reasonable to consider the anchoring force provided by the roots as the minimum value between the maximum pullout resistance of the roots below the sliding surface and the anchoring reaction force of the roots above the sliding surface, based on the geometric characteristics of the sliding surface. When the roots of an 11-year-old C. korshinskii roots were anchored on different sliding blocks of a shallow landslide with a maximum thickness of 2 meters, the stability coefficient of the potential sliding surface increased by 0.020% to 0.408%. When the roots of a single plant were anchored in the middle and upper parts of the potential sliding surface, the stability coefficient of the potential sliding surface was relatively higher than when the plant roots were anchored at the top and bottom positions. Moreover, when four C. korshinskii roots were anchored to the shallow landslide with a row spacing of two sliding blocks (approximately 3 m), the stability coefficient of the potential sliding surface increased by 1.035% to 1.111%, which was significantly higher than when a single C. korshinskii root was anchored (P

[Objective] The effects of different factors on the shear strength index and shear strength of the root-soil interface were analyzed, in order to provide an understanding of the mechanism of shrub root soil fixation and slope protection in the loess region of the Northeastern Tibetan Plateau. [Methods] The dominant shrub (Caragana korshinskii) for this region was selected as the study object, and the effects of the dry density, moisture content, and salt content of soil, and of root diameter on the shear characteristics of the root-soil interface and their mechanisms were analyzed and discussed using the direct shear test (i. e., one factor was varied at a time) for root diameters of (2.20±1.00—32.00±1.80) mm and moisture contents, dry densities, and salt contents of the soil of 6.00%—22.00%, 1.20—1.60 g/cm3, and 0.59%—2.50% respectively. [Results] Root diameter had no significant effect on the shear strength indexes and shear strength of the root-soil interface (p>0.05) when other influencing factors were held constant. As soil moisture content increased from 6.00% to 22.00%, the root-soil interface cohesion initially increased and then decreased, reaching a maximum value of 6.74 kPa at a soil moisture content of 14.00%. The root-soil interface friction angle decreased linearly from 21.40° to 15.75°. The shear strength of the root-soil interface decreased linearly. As the soil dry density increased from 1.20 g/cm3 to 1.60 g/cm3, the cohesion of the root-soil interface increased exponentially from 5.70 kPa to 6.85 kPa, and the friction angle increased linearly from 20.67° to 21.67°. The shear strength of the root-soil interface increased linearly. As the soil salt content increased from 0.59% to 2.50%, the root-soil interface cohesion increased linearly from 6.71 kPa to 7.31 kPa, and the shear strength increased linearly. However, there was no significant change in the root-soil interface friction angle (p>0.05). The gray correlation analysis of these results showed that dry density had the greatest influence on the cohesion, the friction angle, and the shear strength of the root-soil interface. [Conclusion] The dry density, moisture content, and salt content of soil can all affect the shear characteristics of the root-soil interface, however, the degree of influence is different. The influence of rainfall infiltration on the shear characteristics of the root-soil interface should be fully considered when evaluating the protective effect of plant roots on the shallow soil of loess slopes.

Abstract The electrothermal characteristics of metal oxide varistor (MOV), closely related to its microstructure, are important for studying its failure mechanism. This paper proposes an improved MOV microstructure model based on the Voronoi network for simulating the electrothermal behaviour of MOV. With the proposed model, not only the simulation accuracy under constant electrical stress can be improved, but also the simulation of MOV under time‐dependent electrical stress (a.c. or impulse) can be realized. The simulation results are in good agreement with the experimental data. In addition, according to the electrothermal characteristics of MOV microstructure and the failure phenomenon of MOV in the experiments, the failure mechanism of MOV under different electrical stresses is analysed and discussed. It is found that the serious local heating caused by current concentration and thermal stress caused by huge temperature gradient are the main reasons for the MOV failure. This paper provides an effective method for the study of MOV electrothermal characteristics and theoretical reference for the performance improvement of MOV.

The plateau pika (Ochotona curzoniae) actively contributes to soil erosion and meadow degradation in western China’s Yellow River source zone. This study aimed to elucidate the effects of the pika mound numbers on the hydrodynamic characteristics and soil water erosion through simulated rainfall experiments. The inhibition effects of restored vegetation growth on meadow degradation and soil erosion were explored using a revegetated pika mound as a control. The results showed that at a rainfall intensity of 30 mm/h, the soil loss per unit time increased and then decreased with rainfall time and that 15–20 min of rainfall duration was the sensitive period for soil loss in different pika mound patch lands. The degradation of meadows due to the activities of plateau pika is an essential factor influencing soil erosion, and the soil erosion rate is positively correlated with both the pika mound numbers and slope. The mean flow velocity can better describe the process of the soil erosion, and its value increased with the number of pika mounds and slope. The Reynolds number ranged from 57.85 to 153.63 (Re p < 0.01), and both the pika mound numbers and slope were significant factors affecting it (p < 0.05). The Darcy–Weisbach resistance coefficient instead decreased with the pika mound numbers and slope, and the inhibitory effect of vegetation on soil erosion was probably limited when the mound numbers reached a certain level. According to the results of the grey correlation and Pearson correlation analysis, changes in the number of pika mounds led to variability in the soil water erosion properties by altering the landscape scale effect. The number of pika mound patches (NP), edge length index (TE), area index (AREA), and volume index (V) were the key influencing factors on the soil erosion rate and hydrodynamic parameters. We conclude that plateau pika activities intensify meadow degradation, and the continuous increase in pika mounds decreases the vegetation cover and flow resistance and increases soil erodibility. Controlling the intensity of plateau pika activities will effectively prevent soil erosion in degraded areas.

BackgroundRisk scores for predicting in-hospital major bleeding in patients with acute myocardial infarction (AMI) are rare. The Swedish web-system for the enhancement and development of evidence-based care in heart disease evaluated according to recommended therapies (SWEDEHEART) score (SS), consisting of five common clinical variables, is a novel model for predicting in-hospital major bleeding. External validation of SS has not yet been completed.Methods and resultsA retrospective study recruiting consecutive East Asian patients diagnosed with AMI was conducted in the Second Affiliated Hospital, Zhejiang University. The primary endpoint was the ability of SS to predict in-hospital major bleeding, which was defined as Bleeding Academic Research Consortium (BARC) type 3 or 5 bleeding. To validate SS, the discrimination and calibration were assessed in the overall population and several subgroups. The receiver operating characteristic (ROC) curves and the areas under ROC curves (AUCs) were calculated for discrimination. The calibration of SS was evaluated with the unreliability U test. A total of 2,841 patients diagnosed with AMI during hospitalization were included, and 1.94% (55) of them experienced in-hospital major bleeding events. The AUC of SS for the whole population was only 0.60 [95% confidence interval (CI), 0.52–0.67], without an acceptable calibration (p = 0.001). Meanwhile, the highest AUC (0.72; 95% CI, 0.61–0.82) of SS for the primary endpoint was found in the diabetes subgroup, with an acceptable calibration (p = 0.87).ConclusionThis external validation study showed that SS failed to exhibit sufficient accuracy in predicting in-hospital major bleeding among East Asian patients with AMI despite demonstrating acceptable performance in the diabetic subgroup of patients. Studies to uncover optimal prediction tools for in-hospital major bleeding risk in AMI are urgently warranted.

ObjectiveTo explore the association between two polymorphisms of microRNA-143 (miR-143) and the risk of type 2 diabetes mellitus (T2DM) in the northern Chinese Han population.Study DesignThis case–control study involved 326 patients with T2DM and 342 healthy controls. Two genetic variants (rs4705342 and rs353292) of miR-143 were genotyped by the polymerase chain reaction/ligase detection reaction (PCR-LDR) method. The levels of miR-143 in the serum from 52 T2DM patients and 55 healthy subjects were investigated by quantitative real-time PCR (qRT–PCR).ResultsThe CC genotype frequency of rs4705342 was significantly higher in the T2DM patients than in the healthy controls (P = 0.012). After adjusting for sex, age, and body mass index, the rs4705342 CC genotype was also related to a significantly increased risk of T2DM compared with the TT genotype (adjusted OR: 1.87; 95% CI = 1.09-3.19; P = 0.022). Stratified analyses demonstrated that T2DM patients with the rs4705342 CC genotype had significantly higher levels of low-density lipoprotein cholesterol (LDL-C), fasting blood glucose (FBG), and glycated haemoglobin (HbA1C) than those carrying the rs4705342 TT genotype. The qRT–PCR results showed that the expression levels of miR-143 were significantly higher in the serum of cases than in the serum of controls (P < 0.001). Furthermore, the levels of miR-143 were significantly higher in the serum of T2DM patients carrying the rs4705342 CC genotype than in those carrying the TC and TT genotypes of rs4705342 (P = 0.005 and 0.003, respectively).ConclusionThe CC genotype of rs4705342 might be a risk factor for developing T2DM by increasing the expression of miRNA-143 in the northern Chinese Han population.

Aiming at the problem of the low accuracy of projector calibration in a structured light system, an improved projector calibration method is proposed in this paper. One of the key ideas is to estimate the sub-pixel coordinates in the projector image plane using local random sample consensus (RANSAC). A bundle adjustment (BA) algorithm is adopted to optimize the calibration parameters to further improve the accuracy and robustness of the projector calibration. After system calibration and epipolar rectification, the mapping relationship between the pixel coordinates and the absolute phase in the projector image plane is established by using cubic polynomial fitting, and the disparity is rapidly solved by using the mapping relationship, which not only ensures the measurement accuracy, but also improves the measurement efficiency. The experimental results demonstrated that the average re-projection error after optimization is reduced to 0.03 pixels, and the proposed method is suitable for high-speed 3D reconstruction without the time-consuming homogenous point searching.

Series of experiments were performed to simulate the invasion of formation sand into and the plugging process of gravel-pack at different viscosities and flowing rates of fluid. Two types of formation sands with the medium size of 0.10 mm and 0.16 mm and the quartz sand and ceramsite of 0.6—1.2 mm were used in the experiments. A new viscosity-velocity index (the product of fluid viscosity and velocity) was put forward to characterize the influencing mechanism and law of physical property and flow condition of formation fluid on gravel-pack plugging, and a new method to optimize the production rate of wells controlling sand production with gravel-packing was proposed. The results show that the permeability of formation sand invaded zone and final permeability of plugged gravel-pack have negative correlations with viscosity and flow velocity of fluid, the higher the flow velocity and viscosity, the lower the permeability of formation sand invaded zone and final permeability of plugged gravel-pack will be. The flow velocity and viscosity of fluid are key factors affecting plugging degree of the gravel zone. The viscosity-velocity index (v-v index) can reflect the flow characteristics of fluid very well and make it easier to analyze the plugging mechanism of gravel zone. For different combinations of fluid viscosity and flow velocity, if the v-v index is the same or close, their impact on the final gravel permeability would be the same or close. With the increase of the v-v index, the permeability of plugged gravel zone decreases first, then the reduction rate slows down till the permeability stabilizes. By optimizing production and increasing production step by step, the optimal working scheme for sand-control well can reduce the damage to gravel-pack zone permeability caused by sand-carrying fluid effectively, and increase well productivity and extend the sand control life. Key words: gravel-pack, sand retention experiment, plugging law, viscosity-velocity index, working scheme, optimization method, plugging simulation

Abstract Background Many studies have assessed the association between consumption of red and processed meat and the risk of heart failure, but the results are not consistent. This meta-analysis aimed to comprehensively evaluate the relationship between intake of red and processed meat and the risk of heart failure. Methods Databases of Web of Knowledge, PubMed, and Wan Fang Med Online were retrieved up to date of August 31st, 2017. Suitable publications were identified through using the defined inclusion criteria. The summarized relative risk (RR) with the corresponding 95% confidence interval (CI) was calculated. Results Six scientific literatures were included in this study. In comparison with the lowest category, the summarized RR and 95% CI of the highest category of processed meat intake for heart failure risk was 1.23 (95% CI = 1.07–1.41, I 2 = 58.9%, P = 0.045). A significant connection between processed meat intake and heart failure was identified among the Europeans (RR = 1.33, 95% CI = 1.15–1.54), but not the Americans. Yet few of essential association was found between heart failure risk and red meat intake (RR = 1.04, 95% CI = 0.96–1.12). Conclusions Findings of this meta-analysis indicated that the highest category of processed meat intake, other than red meat intake, correlated with an increased risk of heart failure.

Circular RNA (circRNA), a recently identified type of endogenous noncoding RNA, has been implicated in the occurrence and development of a variety of tumors; however, whether circ-SIRT1, derived from pre-mRNA of the parental SIRT1 gene, is involved in colorectal cancer (CRC) remains unknown, as do the potential underlying mechanisms. The expression of circ-SIRT1 in CRC cells and tissue was detected by RT-qPCR. Colony formation and Cell Counting Kit-8 assays were used to evaluate the effect of circ-SIRT1 knockdown on the proliferative ability of CRC cells. Wound healing and Transwell assays were used to assess the effect of circ-SIRT1 knockdown on the migratory and invasive capacity of CRC cells. RNA immunoprecipitation and RNA pull-down assays were employed to validate the binding of circ-SIRT1 to EIF4A3. Western blot was used to identify the changes in the expression of EIF4A3 and EMT-related proteins. The RT-qPCR results showed that circ-SIRT1 was highly expressed in CRC cells and tissue and was positively correlated with the depth of tumor invasion. Knocking down circ-SIRT1 inhibited the proliferation and invasion of CRC cells and EMT. We further found that EIF4A3 could bind to circ-SIRT1, and that overexpressing circ-SIRT1 decreased the abundance of EIF4A3 at the mRNAs of the EMT marker proteins N-cadherin and vimentin. Combined, our findings suggested that circ-SIRT1 regulates the expression of EMT-related proteins by preventing EIF4A3 recruitment to the respective mRNAs. Our results further indicate that circ-SIRT1 functions as an oncogene in CRC by promoting the proliferation, invasion, and EMT of CRC cells through the circ-SIRT1/EIF4A3/N-cadherin/vimentin pathway.

China’s pursuit of economic growth, rapid industrialization, and urbanization over the past few decades has resulted in high energy consumption, which in turn has caused serious environmental pollution problems, such as CO 2 and PM 2.5 emissions, the long-term exposure to which can seriously affect resident health. To resolve these air pollution problems, the Chinese government has put in place several policies to reduce air and environmental pollution. Past studies on energy and environmental efficiency have been mostly static, have ignored the dynamic changes over time and regional differences, and have rarely considered human health factors. Therefore, this study employed a modified meta 2-stage Epsilon-Based Measure (EBM) Malmquist model to explore the relationships between the economy, energy, the environment, health and media, and the regional differences in 31 Chinese cities from 2014 to 2016. It was found that (1) Haikou and Lhasa’s efficiencies were 1 and were the best in all 3 years, and Shijiazhuang, Jinan and Shenyang’s were the most improved; (2) there was a gap between the eastern, central and western technological frontiers, with Chengdu, Hohhot, Chongqing, and Nanchang having technological gap ratios below 0.70 in the western and central Chinese regions, and Haikou, Guangzhou, and Shanghai in eastern China having technological gap ratios above 0.90 in all 3 years; and (3) the variations in the health treatment stage were greater than in the production stage, indicating that technological changes and efficiency improvements in the health treatment stages in each city were not stable.

Colorectal cancer (CRC) appears to be rather refractory to checkpoint blockers except the patient with deficient in mismatch repair (dMMR). Therefore, new advances in the treatment of most mismatch repair proficiency (pMMR) (also known as microsatellite stability, MSS) type of CRC patients are considered to be an important clinical issue associated with programmed death 1 (PD-1) inhibitors. In the present study, we evaluated the effects of gut microbiome of MSS-type CRC tumor-bearing mice treated with different antibiotics on PD-1 antibody immunotherapy response. Our results confirmed that the gut microbiome played a key role in the treatment of CT26 tumor-bearing mice with PD-1 antibody. After PD-1 antibody treatment, the injection of antibiotics counteracted the efficacy of PD-1 antibody in inhibiting tumor growth when compared with the Control group (mice were treated with sterile drinking water). Bacteroides_sp._CAG:927 and Bacteroidales_S24-7 were enriched in Control group. Bacteroides_sp._CAG:927, Prevotella_sp._CAG: 1031 and Bacteroides were enriched in Coli group [mice were treated with colistin (2 mg/ml)], Prevotella_sp._CAG:485 and Akkermansia_muciniphila were enriched in Vanc group [mice were treated with vancomycin alone (0.25 mg/ml)]. The metabolites were enriched in the glycerophospholipid metabolic pathway consistent with the metagenomic prediction pathway in Vanc group, Prevotella_sp._CAG:485 and Akkermansia may maintain the normal efficacy of PD-1 antibody by affecting the metabolism of glycerophospholipid. Changes in gut microbiome leaded to changes in glycerophospholipid metabolism level, which may affect the expression of immune-related cytokines IFN-γ and IL-2 in the tumor microenvironment, resulting in a different therapeutic effect of PD-1 antibody. Our findings show that changes in the gut microbiome affect the glycerophospholipid metabolic pathway, thereby regulating the therapeutic potential of PD-1 antibody in the immunotherapy of MSS-type CRC tumor-bearing mice.

Inborn errors of metabolism (IEMs) have great repercussions in neonatal intensive care units (NICUs). However, the integrative analysis of the incidence for full-term and premature neonates of IEMs in NICUs have not been reported. In this study, we aimed to estimate the incidence of IEMs in the NICU population so as to better evaluate the impact of IEMs on Chinese NICUs. A total of 42,257 newborns (proportion of premature as 36.7%) enrolled to the largest Chinese NICU center for a sequential 7 years screen, and 66 were diagnosed with IEMs. The prevalence of IEMs in total, full-term, and premature infants was 1:640, 1:446, and 1:2,584, respectively. In spectrum of our NICU, diseases that cause endogenous intoxication like methylmalonic acidemia accounted for 93.9% (62/66), and this ratio was higher in full-term infants with 98.3% (59/60), while the most prevalent disease in premature newborn was hyperphenylalaninemia (50%, 3/6), respectively. The genetic analysis of 49 cases revealed 62 potentially pathogenic mutations in 10 well-documented pathogenic genes of IEMs, among which 21 were novel. In conclusion, differences in incidence and spectrum of full-term and premature births we obtained in NICU will provide diagnostic guidelines and therapeutic clues of neonatal IEMs for pediatricians.

The Asiatic toad Bufo gargarizans belongs to Bufonidae. This species is known from the Russian Far East, central, northern and north-eastern China, the Democratic People's Republic of Korea and Japan. In this study, the complete mitochondrial genome of B. gargarizans was sequenced. The mitogenome was 17,407 bp in length, consisting of 13 protein-coding genes, 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes, and a non-coding control region. As in other vertebrates, most mitochondrial genes are encoded on the heavy strand, except for ND6 and eight tRNA genes which are encoded on the light strand. The overall base composition of the B. gargarizans is 28.9% A, 28.2% T, 27.5% C, and 15.3% G. Phylogenetic analysis showed B. gargarizans was closely related to B. bankorensis and B. tibetanus. The complete mitogenome of B. gargarizans can provide an important data for the studies on phylogenetic relationship and population genetics to further explore the taxonomic status of this species.

In the meandering riverbank of the Upper Yellow River (UYR), the native alpine swamp meadow (AS) has continuously degenerated into an alpine meadow (AM) due to climate change and intensified grazing. Its implication on river morphology is still not well known. This study examined this effect by in situ measurings of (1) physical properties of roots and their distribution in the soil-root mixture of the upper bank layer, and (2) the tensile strength in terms of excavating tests for triggering cantilever collapses of AS and AM riverbanks. The results showed that the root number in AS was significantly greater than that in AM, though the root distribution in both was similar. Also, the average tensile strength of individual roots in AS was 31,310 kPa, while that in AM was only 16,155 kPa. For the soil-root mixture, it decreased from 67.39 to 21.96 kPa. The weakened mechanical property was mainly ascribed to the lessened root number and the simpler root structure in the soil-root mixture of AM that reduces its ability to resist the external force. These findings confirmed that healthy AS can enhance bank stability and delay the development of tensile cracks in the riverbank of the meandering rivers in the UYR.

Cavitation phenomenon has strong transient characteristics and is highly influenced by geometric structure. In this study, the cavitation performance with influence of blade tip clearance for a mixed-flow pump is studied using the renormalization group (RNG) k–ε turbulence model and the Zwart–Gerber–Belamri cavitation model. The dominant frequency and maximum amplitude values at non-cavitation condition and different cavitation conditions are compared and associated with flow field features. The results show that the dominant frequency value under incipient cavitation and critical cavitation is 3.2 f i and when the cavitation is severe, the frequency value changes to 3.5 f i . Then, the influence of tip clearance width on cavitation performance of the mixed-flow pump is also discussed. The results show that the increase in tip clearance will significantly aggravate the performance drop of the pump under cavitation conditions. The critical net positive suction head value increases in 4.79% of the value under no-tip clearance condition. At the same time, by the inner flow field observation and analysis, the morphological of cavitation bubbles is also changed, and the cavitation bubbles tend to attach to the blade suction side and the attachment length increases as the tip clearance increases.

Propellers, pumps, and turbines are widely applied in marine equipment, water systems, and hydropower stations. With the increasing demand for energy conservation and environmental protection, the high efficiency and the stable operation of pumps and turbine have been drawing great attention in recent decades. However, the tip clearance between the rotating impeller and the stationary shroud can induce leakage flow and interact with the main stream, introducing complex vortex structures. Consequently, the energy performance and the operation stability of pumps and turbines deteriorate considerably. Constant efforts are exerted to investigate the flow mechanism of tip-clearance flow and its induced influence on performance. However, due to various pump and turbine types and the complexity of tip-clearance flow, previous works are usually focused on a specific issue. Therefore, a systematic review that synthesizes the related research is necessary and meaningful. This review investigates related research in the recent two decades in the perspectives from fundamental physics to engineering applications. Results reveal the vortex types, trajectory, evolution, and cavitation behaviors induced by tip-clearance flow. It is concluded that the influence characteristics of tip clearance on energy performance are closely related to the machinery type. Tip-clearance size and tip shape are found to be crucial parameters for tip-leakage vortex (TLV). The proposed optimization schemes are also demonstrated to provide inspiration for future research. Overall, this review article provides a coherent insight into the characteristics of tip-clearance flow and the associated engineering-design applications. On the basis of these understandings, comments on conducted research and ideas on future research are proposed.

The energy performance and pressure fluctuations in a centrifugal pump with inlet guide vanes (IGVs) are investigated experimentally and numerically in a prewhirl angle range of −24° to 24° and in an axial distance range of 280 mm, 380 mm, and 460 mm. The reliability and accuracy of the numerical method are validated by the satisfactory agreement between the experimental data and numerical results. Prewhirl regulation with IGVs can significantly increase the energy performance and broaden the efficient operation range for the centrifugal pump due to the improvement of flow pattern at the impeller inlet. The prewhirl angle has an obvious impact on pump energy performance, and the maximum amplitudes of pressure fluctuations on the blade leading edge of the pressure and suction sides decrease by 69% and 89%, respectively. The axial distance has a slight impact on pump energy performance, but the maximum amplitudes of pressure fluctuations drop by 35.4% on the blade leading edge of pressure side when the axial distance extends from 280 mm to 460 mm.

Tip clearance between blade end and shroud is inevitable in pump operation and of great importance on pump energy performance and pressure fluctuation. As the tip clearance size increases, the head and efficiency of the mixed flow pump drop accordingly. The simulation results show that the development of a leakage vortex is observed as the tip clearance increases, and the trajectory of this leakage vortex remains in the same direction along the blade suction side for different tip clearances. With the increase in tip clearance size, the intensity of the leakage vortex is enhanced, and the separation between the main leakage vortex and the secondary leakage vortex is also strengthened. The leakage separation angle near the blade tip remains at the same value of 10° for different tip clearance sizes. As for the spectrum analysis, the maximum amplitudes of pressure fluctuations dramatically increase in the impeller when the tip clearance increases from 0.0 mm to 1.0 mm, and the dominant frequencies go from 145 Hz to 184 Hz due to the considerable leakage flow.

The energy performance and radial force of a mixed flow pump with symmetrical and unsymmetrical tip clearance are investigated in this paper. As the tip clearance increases, the pump head and efficiency both decrease. The center of the radial force on the principal axis is located at the coordinate origin when the tip clearance is symmetrical, and moves to the third quadrant when the tip clearance is unsymmetrical. Analysis results show that the total radial force on the principal axis is closely related to the fluctuation of mass flow rate in each single flow channel. Unsteady simulations show that the dominant frequencies of radial force on the hub and blade correspond to the blade number, vane number, or double blade number because of the rotor stator interaction. The radial force on the blade pressure side decreases with the tip clearance increase because of leakage flow. The unsymmetrical tip clearances in an impeller induce uneven leakage flow rate and then result in unsymmetrical work ability of each blade and flow pattern in each channel. Thus, the energy performance decreases and the total radial force increases for a mixed flow pump with unsymmetrical tip clearance.

In acute promyelocytic leukemia (APL), the promyelocytic leukemia-retinoic acid receptor alpha (PML/RARα) fusion protein destroys PML nuclear bodies (NBs), leading to the formation of microspeckles. However, our understanding, largely learned from morphological observations, lacks insight into the mechanisms behind PML/RARα-mediated microspeckle formation and its role in APL leukemogenesis. This study presents evidence uncovering liquid-liquid phase separation (LLPS) as a key mechanism in the formation of PML/RARα-mediated microspeckles. This process is facilitated by the intrinsically disordered region containing a large portion of PML and a smaller segment of RARα. We demonstrate the coassembly of bromodomain-containing protein 4 (BRD4) within PML/RARα-mediated condensates, differing from wild-type PML-formed NBs. In the absence of PML/RARα, PML NBs and BRD4 puncta exist as two independent phases, but the presence of PML/RARα disrupts PML NBs and redistributes PML and BRD4 into a distinct phase, forming PML/RARα-assembled microspeckles. Genome-wide profiling reveals a PML/RARα-induced BRD4 redistribution across the genome, with preferential binding to super-enhancers and broad-promoters (SEBPs). Mechanistically, BRD4 is recruited by PML/RARα into nuclear condensates, facilitating BRD4 chromatin binding to exert transcriptional activation essential for APL survival. Perturbing LLPS through chemical inhibition (1, 6-hexanediol) significantly reduces chromatin co-occupancy of PML/RARα and BRD4, attenuating their target gene activation. Finally, a series of experimental validations in primary APL patient samples confirm that PML/RARα forms microspeckles through condensates, recruits BRD4 to coassemble condensates, and co-occupies SEBP regions. Our findings elucidate the biophysical, pathological, and transcriptional dynamics of PML/RARα-assembled microspeckles, underscoring the importance of BRD4 in mediating transcriptional activation that enables PML/RARα to initiate APL. [ABSTRACT FROM AUTHOR]

In order to study the infiltration characteristics of grassland soil in the super large scale landslides distribution area in the upper reaches of the Yellow River, this study selected the Xiazangtan super large scale distribution area in Jianzha County as the study area. Through experiments and numerical simulations, plant roots characteristics, soil physical properties and infiltration characteristics of naturally grazed grassland and enclosed grassland with different slope directions were compared and analyzed, and the influence of rainfall on seepage field and stability of the two grassland slopes were discussed. The results show that the highest soil moisture infiltration capacity (FIR) is found on the shady slope of the enclosed grassland (2.25), followed by the sunny slope of the enclosed grassland (1.23) and the shady slope of the naturally grazed grassland (-0.87). Correlation analysis show that soil water content, root dry weight density, total soil porosity, number of forks and root length are positively correlated with infiltration rate (P <0.05), whereas soil dry density is negatively correlated with infiltration rate (P<0.05). The results of stepwise regression analyses show that soil water content, total soil porosity, root length and number of forks are the main factors affecting soil infiltration capacity. And the ability of roots to increase soil infiltration by improving soil properties is higher than the effect of roots itself. After 60 min of simulated rainfall, the safety factors of the shady slopes of naturally grazed grassland and enclosed grassland are reduced by 29.56% and 19.63%, respectively, comparing to those before rainfall. Therefore, in this study, the roots play a crucial role in regulating soil infiltration and enhance slope stability by increasing soil water content, soil total porosity and shear strength while decreasing soil dry density. The results of this study provide theoretical evidence and practical guidance for the effective prevention and control of secondary geological disasters such as soil erosion and shallow landslide on the slope of river banks in the study area by using plant ecological measures. [ABSTRACT FROM AUTHOR]