Advances in GNSS Positioning and GNSS Remote Sensing.

Scientists and engineers use data utilize global navigation satellite systems (GNSSs) for a multitude of tasks: autonomous navigation, transport monitoring, construction, GNSS reflectometry, GNSS ionosphere monitoring, etc [...].

PKM2 Aggravates Cerebral Ischemia Reperfusion-Induced Neuroinflammation via TLR4/MyD88/TRAF6 Signaling Pathway.

OBJECTIVES: Cerebral ischemia-reperfusion (I/R) injury is the leading cause of ischemic stroke. Pyruvate Kinase isozymes M2 (PKM2), as a critical glycolytic enzyme during glycolysis, is involved in neuronal apoptosis in rats with hypoxic-ischemic encephalopathy. This study focused on functional investigation and potential molecular mechanism toward PKM2 in cerebral I/R injury. METHODS: Cerebral I/R injury model was established by middle cerebral artery occlusion (MCAO) in vivo or oxygen-glucose deprivation and reoxygenation (OGD/R) in vitro. qRT-PCR and Western blot were used to detect the expression of PKM2 in I/R injury models. The effects of PKM2 on I/R injury were determined via triphenyl tetrazolium chloride staining and evaluation of neurological deficits. Cell Counting Kit-8 was employed to detect cell viability, and ELISA was conducted to detect pro-inflammatory cytokines. The underlying mechanism involved in regulation of PKM2 on I/R injury was investigated via ELISA and Western blot. RESULTS: PKM2 was upregulated after cerebral I/R injury. Knockdown of PKM2 alleviated MCAO-induced infarction and neurological dysfunction. Moreover, PKM2 knockdown also alleviated OGD/R-induced neuronal cell injury and inflammatory response. Mechanistically, PKM2 knockdown-induced neuroprotection was accompanied by inhibition of high-mobility group box 1 (HMGB1), reflected by inactivation of TLR4/MyD88 (myeloid differentiation factor 88)/TRAF6 (TNF receptor-associated factor 6) signaling pathway. CONCLUSIONS: Knockdown of PKM2 attenuated cerebral I/R injury through HMGB1-mediated TLR4/MyD88/TRAF6 expression change, providing a potential target for cerebral I/R injury treatment.

Insights into non-symbiotic plant growth promotion bacteria associated with nodules of Sphaerophysa salsula growing in northwestern China.

In addition to rhizobia, other non-symbiotic endophytic bacteria also have been simultaneously isolated from the same root nodules. The existence of non-symbiotic endophytic bacteria in leguminous root nodules is a universal phenomenon. The vast majority of studies have detected endophytic bacteria in other plant tissues. In contrast, little systemic observation has been made on the non-symbiotic endophytic bacteria within leguminous root nodules. The present investigation was carried out to isolate plant growth-promoting endophytic non-symbiotic bacteria from indigenous leguminous Sphaerophysa salsula and their influence on plant growth. A total of 65 endophytic root nodule-associated bacteria were isolated from indigenous legume S. salsula growing in the northwestern arid regions of China. When combining our previous work with the current study, sequence analysis of the nifH gene revealed that the strain belonging to non-nodulating Bacillus pumilus Qtx-10 had genes similar to those of Rhizobium leguminosarum Qtx-10-1. The results indicated that horizontal gene transfer could have occurred between rhizobia and non-symbiotic endophyties. Under pot culture conditions, out of the 20 representative endophytic isolates, 15 with plant growth-promoting traits, such as IAA production, ACC deaminase, phosphate solubilization, chitinase, siderophore, and fungal inhibition activity showed plant growth-promoting activity with respect to various plant parameters such as chlorophyll content, fresh weight of plant, shoot length, nodule number per plant and average nodule weight per plant when co-inoculated with rhizobial bioinoculant Mesorhizobium sp. Zw-19 under N-free culture conditions. Among them, Bacillus pumilus Qtx-10 and Streptomyces bottropensis Gt-10 were excellent plant growth-promoting bacteria, which enhanced the seeding fresh weight by 87.5% and the shoot length by 89.4%, respectively. The number of nodules grew more than 31.89% under field conditions. Our findings indicate the frequent presence of these non-symbiotic endophytic bacteria within root nodules, and that they help to improve nodulation and nitrogen fixation in legume plants through synergistic interactions with rhizobia.

Effects of livestock grazing on grassland carbon storage and release override impacts associated with global climate change.

Predicting future carbon (C) dynamics in grassland ecosystems requires knowledge of how grazing and global climate change (e.g., warming, elevated CO2 , increased precipitation, drought, and N fertilization) interact to influence C storage and release. Here, we synthesized data from 223 grassland studies to quantify the individual and interactive effects of herbivores and climate change on ecosystem C pools and soil respiration (Rs). Our results showed that grazing overrode global climate change factors in regulating grassland C storage and release (i.e., Rs). Specifically, grazing significantly decreased aboveground plant C pool (APCP), belowground plant C pool (BPCP), soil C pool (SCP), and Rs by 19.1%, 6.4%, 3.1%, and 4.6%, respectively, while overall effects of all global climate change factors increased APCP, BPCP, and Rs by 6.5%, 15.3%, and 3.4% but had no significant effect on SCP. However, the combined effects of grazing with global climate change factors also significantly decreased APCP, SCP, and Rs by 4.0%, 4.7%, and 2.7%, respectively but had no effect on BPCP. Most of the interactions between grazing and global climate change factors on APCP, BPCP, SCP, and Rs were additive instead of synergistic or antagonistic. Our findings highlight the dominant effects of grazing on C storage and Rs when compared with the suite of global climate change factors. Therefore, incorporating the dominant effect of herbivore grazing into Earth System Models is necessary to accurately predict climate-grassland feedbacks in the Anthropocene.

Lingguizhugan decoction attenuates doxorubicin-induced heart failure in rats by improving TT-SR microstructural remodeling.

BACKGROUND: Lingguizhugan decoction (LGZG), an ancient Chinese herbal formula, has been used to treat cardiovascular diseases in eastern Asia. We investigated whether LGZG has protective activity and the mechanism underlying its effect in an animal model of heart failure (HF). METHODS: A rat model of HF was established by administering eight intraperitoneal injections of doxorubicin (DOX) (cumulative dose of 16 mg/kg) over a 4-week period. Subsequently, LGZG at 5, 10, and 15 mL/kg/d was administered to the rats intragastrically once daily for 4 weeks. The body weight, heart weight index (HWI), heart weight/tibia length ratio (HW/TL), and serum BNP level were investigated to assess the effect of LGZG on HF. Echocardiography was performed to investigate cardiac function, and H&E staining to visualize myocardial morphology. Myocardial ultrastructure and T-tubule-sarcoplasmic reticulum (TT-SR) junctions were observed by transmission electron microscopy. The JP-2 protein level was determined by Western blotting. The mRNA level of CACNA1S and RyR2 and the microRNA-24 (miR-24) level were assayed by quantitative RT-PCR. RESULTS: Four weeks after DOX treatment, rats developed cardiac damage and exhibited a significantly increased BNP level compared with the control rats (169.6 ± 29.6 pg/mL versus 80.1 ± 9.8 pg/mL, P < 0.001). Conversely, LGZG, especially at the highest dose, markedly reduced the BNP level (93.8 ± 17.9 pg/mL, P < 0.001). Rats treated with DOX developed cardiac dysfunction, characterized by a strong decrease in left ventricular ejection fraction compared with the control (58.5 ± 8.7% versus 88.7 ± 4.0%; P < 0.001). Digoxin and LGZG improved cardiac dysfunction (79.6 ± 6.1%, 69.2 ± 2.5%, respectively) and preserved the left ventricular ejection fraction (77.9 ± 5.1, and 80.5 ± 4.9, respectively, P < 0.01). LGZG also improved the LVEDD, LVESD, and FS and eliminated ventricular hypertrophy, as indicated by decreased HWI and HW/TL ratio. LGZG attenuated morphological abnormalities and mitochondrial damage in the myocardium. In addition, a high dose of LGZG significantly downregulated the expression of miR-24 compared with that in DOX-treated rats (fold change 1.4 versus 3.4, P < 0.001), but upregulated the expression of JP-2 and antagonized DOX-induced T-tubule TT-SR microstructural remodeling. These activities improved periodic Ca2+ transients and cell contraction, which may underly the beneficial effect of LGZG on HF. CONCLUSIONS: LGZG exerted beneficial effects on DOX-induced HF in rats, which were mediated in part by improved TT-SR microstructural remodeling.

A Method Framework for Automatic Airspace Reconfiguration-Monte Carlo Method for Eliminating Irregular Sector Shapes Generated by Region Growth Method.

With the growth of air traffic demand in busy airspace, there is an urgent need for airspace sectorization to increase air traffic throughput and ease the pressure on controllers. The purpose of this paper is to develop a method framework that can perform airspace sectorization automatically, reasonably, which can be used as an advisory tool for controllers as an automatic system, especially for eliminating irregular sector shapes generated by simulated annealing algorithm (SAA) based on the region growth method. The two graph cutting method, dynamic Monte Carlo method by changing location of flexible vertices (MC-CLFV) and Monte Carlo method by radius changing (MC-RC) were developed to eliminate irregular sector shapes generated by SAA in post-processing. The experimental results show that the proposed method framework of airspace sectorization (AS) can automatically and reasonably generate sector design schemes that meet the design criteria. Our methodology framework and software can provide assistant design and analysis tools for airspace planners to design airspace, improve the reliability and efficiency of airspace design, and reduce the burden of airspace planners. In addition, this lays the foundation for reconstructing airspace with the more intelligent method.

p63 protects chondrosarcoma malignancies mainly by enhancing the expression of PTEN.

Abnormal expression of p63 has been well identified in multiple malignancies. However, little study has been done on the association between p63 and chondro sarcoma. In the current study, we mainly explored the expression of p63 in different grades of chondrosarcoma. Our data showed that p63 was significantly decreased in grade II and III chondrosarcoma compared with that of grade I chondrosarcoma and normal control. As the characteristic of grade II and III chondrosarcoma is metastasis, we then searched the function of p63 chondrosarcoma. In vitro study showed that overexpression of p63 significantly suppressed chondrosarcoma cell viability, migration and invasion. Meanwhile, upregualtion of p63 induced chondrosarcoma cell apoptosis. Furthermore, we showed that overexpression of p63 could significantly increase the protein expression of PTEN. In contrast, silencing of PTEN markedly reduced the protein levels of Bax, and enhanced the expression of PCNA and p27, even in cells transfected with p-p63. These data showed that p63 was a tumor suppressor mainly through regulating PTEN in chondrosarcoma cells. In summary, reduction of p63 in grade II and III chondrosarcoma enhances the malignant phenotype mainly through modulating the expression of PTEN.

Tuning the resonance properties of 2D carbon nanotube networks towards a mechanical resonator.

The capabilities of the mechanical resonator-based nanosensors in detecting ultra-small mass or force shifts have driven a continuing exploration of the palette of nanomaterials for such application purposes. Based on large-scale molecular dynamics simulations, we have assessed the applicability of a new class of carbon nanomaterials for nanoresonator usage, i.e. the single-wall carbon nanotube (SWNT) network. It is found that SWNT networks inherit excellent mechanical properties from the constituent SWNTs, possessing a high natural frequency. However, although a high quality factor is suggested from the simulation results, it is hard to obtain an unambiguous Q-factor due to the existence of vibration modes in addition to the dominant mode. The nonlinearities resulting from these extra vibration modes are found to exist uniformly under various testing conditions including different initial actuations and temperatures. Further testing shows that these modes can be effectively suppressed through the introduction of axial strain, leading to an extremely high quality factor in the order of 10(9) estimated from the SWNT network with 2% tensile strain. Additional studies indicate that the carbon rings connecting the SWNTs can also be used to alter the vibrational properties of the resulting network. This study suggests that the SWNT network can be a good candidate for applications as nanoresonators.

Biomechanical comparison of a novel transoral atlantoaxial anchored cage with established fixation technique - a finite element analysis.

BACKGROUND: The transoral atlantoaxial reduction plate (TARP) fixation has been introduced to achieve reduction, decompression, fixation and fusion of C1-C2 through a transoral-only approach. However, it may also be associated with potential disadvantages, including dysphagia and load shielding of the bone graft. To prevent potential disadvantages related to TARP fixation, a novel transoral atlantoaxial fusion cage with integrated plate (Cage + Plate) device for stabilization of the C1-C2 segment is designed. The aims of the present study were to compare the biomechanical differences between Cage + Plate device and Cage + TARP device for the treatment of basilar invagination (BI) with irreducible atlantoaxial dislocation (IAAD). METHODS: A detailed, nonlinear finite element model (FEM) of the intact upper cervical spine had been developed and validated. Then a FEM of an unstable BI model treated with Cage + Plate fixation, was compared to that with Cage + TARP fixation. All models were subjected to vertical load with pure moments in flexion, extension, lateral bending and axial rotation. Range of motion (ROM) of C1-C2 segment and maximum von Mises Stress of the C2 endplate and bone graft were quantified for the two devices. RESULTS: Both devices significantly reduced ROM compared with the intact state. In comparison with the Cage + Plate model, the Cage + TARP model reduced the ROM by 82.5 %, 46.2 %, 10.0 % and 74.3 % in flexion, extension, lateral bending, and axial rotation. The Cage + Plate model showed a higher increase stresses on C2 endplate and bone graft than the Cage + TARP model in all motions. CONCLUSIONS: Our results indicate that the novel Cage + Plate device may provide lower biomechanical stability than the Cage + TARP device in flexion, extension, and axial rotation, however, it may reduce stress shielding of the bone graft for successful fusion and minimize the risk of postoperative dysphagia. Clinical trials are now required to validate the reproducibility and advantages of our findings using this anchored cage for the treatment of BI with IAAD.

Different responses of soil respiration and its components to nitrogen addition among biomes: a meta-analysis.

Anthropogenic activities have increased nitrogen (N) deposition by threefold to fivefold over the last century, which may considerably affect soil respiration (Rs). Although numerous individual studies and a few meta-analyses have been conducted, it remains controversial as to how N addition affects Rs and its components [i.e., autotrophic (Ra) and heterotrophic respiration (Rh)]. To reconcile the difference, we conducted a comprehensive meta-analysis of 295 published studies to examine the responses of Rs and its components to N addition in terrestrial ecosystems. We also assessed variations in their responses in relation to ecosystem types, environmental conditions, and experimental duration (DUR). Our results show that N addition significantly increased Rs by 2.0% across all biomes but decreased by 1.44% in forests and increased by 7.84% and 12.4% in grasslands and croplands, respectively (P < 0.05). The differences may largely result from diverse responses of Ra to N addition among biomes with more stimulation of Ra in croplands and grasslands compared with no significant change in forests. Rh exhibited a similar negative response to N addition among biomes except that in croplands, tropical and boreal forests. Methods of partitioning Rs did not induce significant differences in the responses of Ra or Rh to N addition, except that Ra from root exclusion and component integration methods exhibited the opposite responses in temperate forests. The response ratios (RR) of Rs to N addition were positively correlated with mean annual temperature (MAT), with being more significant when MAT was less than 15 °C, but negatively with DUR. In addition, the responses of Rs and its components to N addition largely resulted from the changes in root and microbial biomass and soil C content as indicated by correlation analysis. The response patterns of Rs to N addition as revealed in this study can be benchmarks for future modeling and experimental studies.

Dexmedetomidine activates the PKA/CREB pathway and inhibits proinflammatory factor expression through ß2 adrenergic receptors.

INTRODUCTION: Dexmedetomidine (DEX) is primarily utilized for sedation in the context of general anesthesia or intensive care. However, the exact regulatory mechanism by which DEX affects cytokines remains unclear. This study aims to investigate the underlying mechanism by which DEX inhibits proinflammatory factors through activation of the ß2 adrenergic receptor (ß2 AR). METHODS: The inflammatory cell model of human mononuclear macrophage (THP-1) cells induced by lipopolysaccharide (LPS) was established to study the effect of DEX on the expression of cell-related inflammatory factors. ADRA2A gene knockout THP-1 cells (THP-1KO ) were constructed by CRISPR technology, and the effect of DEX on the expression of inflammatory factors of THP-1KO cells was detected. The target sites of DEX on ß2 AR were screened by molecular docking. Reversion experiments were performed using ADRB2-siRNA. Western blot was used to detect the activation of ß2 AR/PKA/CREB pathway and NF-κB, and ELISA was used to detect the release level of inflammatory factors. RESULTS: The results demonstrated a significant reduction in the expression levels of MCP-1, interleukin-06, and IL-8 in both THP-1 and THP-1KO cells when induced by LPS following treatment with DEX. Additionally, DEX treatment led to an increase in IL-10 expression. Immunofluorescence analysis revealed an upregulation of ß2 AR expression after DEX treatment. Western blot results indicated that DEX notably enhanced the activation of the ß2 AR and PKA/CREB pathways, while concurrently suppressing the activation of NF-κB. Notably, the use of ADRB2 siRNA reversed the effects of DEX treatment and promoted the release of inflammatory cytokines. CONCLUSION: DEX initiates the activation of the PKA/CREB pathway through the activation of ß2 AR. Simultaneously, it exerts an inhibitory effect on the activation of NF-κB, consequently reducing the transcription of proinflammatory factors while increasing the transcription of anti-inflammatory factors.

Contrastive learning based method for X-ray and CT registration under surgical equipment occlusion.

Deep learning-based 3D/2D surgical navigation registration techniques achieved excellent results. However, these methods are limited by the occlusion of surgical equipment resulting in poor accuracy. We designed a contrastive learning method that treats occluded and unoccluded X-rays as positive samples, maximizing the similarity between the positive samples and reducing interference from occlusion. The designed registration model has Transformer's residual connection (ResTrans), which enhances the long-sequence mapping capability, combined with the contrast learning strategy, ResTrans can adaptively retrieve the valid features in the global range to ensure the performance in the case of occlusion. Further, a learning-based region of interest (RoI) fine-tuning method is designed to refine the misalignment. We conducted experiments on occluded X-rays that contained different surgical devices. The experiment results show that the mean target registration error (mTRE) of ResTrans is 3.25 mm and the running time is 1.59 s. Compared with the state-of-the-art (SOTA) 3D/2D registration methods, our method offers better performance on occluded 3D/2D registration tasks.

Thermodynamics of "exotic" Bañados-Teitelboim-Zanelli black holes.

A number of three-dimensional (3D) gravity models, such as 3D conformal gravity, admit "exotic" black hole solutions: the metric is the same as the Bañados-Teitelboim-Zanelli metric of 3D Einstein gravity but with reversed roles for mass and angular momentum, and an entropy proportional to the length of the inner horizon instead of the event horizon. Here we show that the Bañados-Teitelboim-Zanelli solutions of the exotic 3D Einstein gravity (with parity-odd action but Einstein field equations) are exotic black holes, and we investigate their thermodynamics. The first and second laws of black hole thermodynamics still apply, and the entropy still has a statistical interpretation.

Aptamer-based turn-on detection of thrombin in biological fluids based on efficient phosphorescence energy transfer from Mn-doped ZnS quantum dots to carbon nanodots.

This paper presents the first example of a sensitive, selective, and stable phosphorescent sensor based on phosphorescence energy transfer (PET) for thrombin that functions through thrombin-aptamer recognition events. In this work, an efficient PET donor-acceptor pair using Mn-doped ZnS quantum dots labeled with thrombin-binding aptamers (TBA QDs) as donors, and carbon nanodots (CNDs) as acceptors has been constructed. Due to the π-π stacking interaction between aptamer and CNDs, the energy donor and acceptor are taken into close proximity, leading to the phosphorescence quenching of donors, TBA QDs. A maximum phosphorescence quenching efficiency as high as 95.9% is acquired. With the introduction of thrombin to the "off state" of the TBA-QDs-CNDs system, the phosphorescence is "turned on" due to the formation of quadruplex-thrombin complexes, which releases the energy acceptor CNDs from the energy donors. Based on the restored phosphorescence, an aptamer-based turn-on thrombin biosensor has been demonstrated by using the phosphorescence as a signal transduction method. The sensor displays a linear range of 0-40 nM for thrombin, with a detection limit as low as 0.013 nM in pure buffers. The proposed aptasensor has also been used to monitor thrombin in complex biological fluids, including serum and plasma, with satisfactory recovery ranging from 96.8 to 104.3%. This is the first time that Mn-doped ZnS quantum dots and CNDs have been employed as a donor-acceptor pair to construct PET-based biosensors, which combines both the photophysical merits of phosphorescence QDs and the superquenching ability of CNDs and thus affords excellent analytical performance. We believe this proposed method could pave the way to a new design of biosensors using PET systems.

Effectiveness and safety of metoclopramide in treatment of intractable hiccup: a protocol of systematic review and meta-analysis.

INTRODUCTION: Hiccup is a common disease that not only occurred on adults but also on infants, which can severely do harm to patients' physical and psychological health. Metoclopramide has been reported to have effects on intractable hiccup. However, there is a limited evidence that describes the efficacy and safety of metoclopramide in the treatment of intractable hiccup. The aim of this article is to obtain evidence on the effectiveness and safety of metoclopramide in treating patients with intractable hiccup. METHODS AND ANALYSIS: We will search the following databases, including PubMed, Cochrane Library, Embase, Web of Science, CBM, Wan-fang, VIP database, CNKI and MEDLINE from their inception to 11 November 2021. All the randomised controlled trials associated with metoclopramide in treating intractable hiccup will be included. Articles screened, selected and extracted will be performed by two researchers independently. The risk of bias will be assessed by using the Cochrane Collaboration. We will carry out the meta-analysis by using RevMan V.5.4 software. PROSPERO REGISTRATION NUMBER: CRD42021293000.

Differential responses of leaf photosynthesis to insect and pathogen outbreaks: A global synthesis.

Outbreak of insects or pathogens (referred to as biotic disturbance), which is projected to continually increase in a warmer climate, may profoundly affect plant photosynthesis and production. However, the response of plant photosynthesis to biotic disturbance remains unclear, especially differences in response between insects and pathogens, which hinders the prediction of plant productivity in future climate. In this study, a meta-analysis approach was used to examine effects of insects and pathogens on photosynthetic rate per unit leaf area (Pn) and the associated characteristics from 115 studies. Our results showed that biotic disturbance significantly decreased Pn by 34.8% but increased Rd by 26.2%. Most of parameters associated with Pn were significantly reduced by biotic disturbance, including gs, Tr, photosynthetic pigments (e.g., a+b, a, and b), and chlorophyll fluorescence properties (Fv/Fm, qp). The disturbance type (insects vs pathogens) was the most important factor affecting the response of Pn, with a greater decrease in Pn by pathogens (-37.5%) than insects (-28.0%). The response ratio of Pn was positively correlated with that of gs and Tr for both insects and pathogens, while negatively with Ci and positively with Chl a+b, ΦPSII, and qp for only pathogens. In addition, the higher sensitivity of Pn to biotic disturbance in crop than non-crop plants poses a great challenge to agricultural system in the future. The weighted response ratio of Pn and relationships of Pn with other associated paramerters under insect and pathogen disturbance will facilitate vegetation models to integrate the effects of biotic disturbance on primary production, improving predicition of the ecosystem carbon cyling in combining with leaf area measurement.

Polylactic acid scaffold with directional porous structure for large-segment bone repair.

Biodegradable porous scaffolds with different structure, porosity, and strength play a critical role in the repair and regeneration of defects in bone tissue engineering by changing the proliferation condition for cell. In this study, polylactic acid (PLA) scaffold with directional porous structure is designed and fabricated using the method of ice template and phase inversion for speeding up bone repair by promoting the growth and proliferation of bone cells. The morphology, mechanical properties, hydrophilicity, and wicking properties of PLA scaffolds were characterized by scanning electron microscope, universal testing machine, contact angle tester and wicking rate test, respectively. In vitro biocompatibility has been investigated through measuring cell adhesion, proliferation, and viability on PLA scaffold with directional porous structure. Prepared PLA scaffold was implanted into animals to observe the repair mechanism of large-sized bone defects. This study proposes a novel bioporous scaffold design to induce osteocyte growth at the rat calvaria with a directional pore structure, and the scaffold edges were integrated with the calvaria at week 12, effectively promoting the repair and regeneration of defective bone tissue.

A New Approach for Modeling Mixed Lubricated Piston-Cylinder Pairs of Variable Lengths in Swash-Plate Axial Piston Pumps.

The swash-plate axial piston pump is one of the most widely used pumps due to its simplicity and compactness in structure. In such a pump, the piston-cylinder system plays a crucial role, with its lubrication characteristics greatly affecting the overall pumping performance. A new numerical approach is proposed in this study for modeling mixed lubricated piston-cylinder interfaces of variable lengths in swash-plate axial piston pumps in the framework of multibody dynamics. The approach couples the hydrodynamic mixed lubrication model of the piston-cylinder interface with the multibody dynamics model of the piston pump. The lubrication model is established with a transient average Reynolds equation considering asperity contacts and is solved with the finite element method to derive the hydrodynamic forces of the lubricated pair, while the multibody dynamics model is established with Lagrangian formalism by considering hydrodynamic forces as external forces. Results for piston-cylinder interfaces of variable lengths in swash-plate axial piston pumps are presented, and the impacts of cylinder length and the tilt angle of the swash plate on the tribological performances of the interface are discussed. The results indicate that increasing the cylinder length can improve the stability and wear resistance of the piston, but it can exacerbate the frictional power loss. Moreover, although enlarging the tilt angle of the swash plate can effectively increase pump displacement, it can easily lead to serious friction, wear, and leakage problems. Consequently, the tilt angle of the swash plate should be carefully selected in practical applications.

Small-diameter polyurethane vascular graft with high strength and excellent compliance.

In this study, a polyurethane vascular graft with excellent strength and compliance for clinical application was designed and fabricated by preparing three small-diameter vascular graft layers via the textile techniques of wet spinning and knitting. The polyurethane filament that was fabricated by wet spinning formed the inner layer. The polyurethane tubular fabric was used as the middle layer. The outer layer was prepared by spraying polyurethane solution. The three layers of the polyurethane vascular graft have uniform wall thickness, high strength, excellent compliance, and good puncture resistance compared with clinical poly(ethylene terephthalate) (PET) and expanded polytetrafluoroethylene (ePTFE) vascular graft. Therefore, these layers can have potential clinical applications in the replacement of the conventional artificial vascular graft prepared from PET and ePTFE.

Root-Associated Endophytic Bacterial Community Composition of Pennisetum sinese from Four Representative Provinces in China.

Pennisetum sinese, a source of bio-energy with high biomass production, is a species that contains high crude protein and will be useful for solving the shortage of forage grass after the implementation of "Green for Grain" project in the Loess plateau of Northern Shaanxi in 1999. Plants may receive benefits from endophytic bacteria, such as the enhancement of plant growth or the reduction of plant stress. However, the composition of the endophytic bacterial community associated with the roots of P. sinese is poorly elucidated. In this study, P. sinese from five different samples (Shaanxi province, SX; Fujian province, FJ; the Xinjiang Uyghur autonomous prefecture, XJ and Inner Mongolia, including sand (NS) and saline-alkali land (NY), China) were investigated by high-throughput next-generation sequencing of the 16S rDNA V3-V4 hypervariable region of endophytic bacteria. A total of 313,044 effective sequences were obtained by sequencing five different samples, and 957 effective operational taxonomic units (OTUs) were yielded at 97% identity. The phylum Proteobacteria, the classes Gammaproteobacteria and Alphaproteobacteria, and the genera Pantoea, Pseudomonas, Burkholderia, Arthrobacter, Psychrobacter, and Neokomagataea were significantly dominant in the five samples. In addition, our results demonstrated that the Shaanxi province (SX) sample had the highest Shannon index values (3.795). We found that the SX (308.097) and NS (126.240) samples had the highest and lowest Chao1 richness estimator (Chao1) values, respectively. Venn graphs indicated that the five samples shared 39 common OTUs. Moreover, according to results of the canonical correlation analysis (CCA), soil total carbon, total nitrogen, effective phosphorus, and pH were the major contributing factors to the difference in the overall composition of the bacteria community in this study. Our data provide insights into the endophytic bacteria community composition and structure of roots associated with P. sinese. These results might be useful for growth promotion in different samples, and some of the strains may have the potential to improve plant production in future studies.