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Cisplatin is recommended as a first-line chemotherapeutic agent against advanced non-small cell lung cancer (NSCLC), but acquired resistance substantially limits its clinical efficacy. Recently, DNA methylation has been identified as an essential contributor to chemoresistance. However, the precise DNA methylation regulatory mechanism of cisplatin resistance remains unclear. Here, we found that nicotinamide nucleotide transhydrogenase (NNT) was silenced by DNA hypermethylation in cisplatin resistance A549 (A549/DDP) cells. Also, the DNA hypermethylation of NNT was positively correlated to poor prognosis in NSCLC patients. Overexpression of NNT in A549/DDP cells could reduce their cisplatin resistance, and also suppressed their tumor malignancy such as cell proliferation and clone formation. However, NNT enhanced sensitivity of A549/DDP cells to cisplatin had little to do with its function in mediating NADPH and ROS level, but was mainly because NNT could inhibit protective autophagy in A549/DDP cells. Further investigation revealed that NNT could decrease NAD

Axial thermal deformation and axial stiffness are main technical indicators to affect manufacturing accuracy of face-grinding spindle. However, the face-grinding spindle supported by rolling bearings lubricated with grease has a relative disadvantage in respect of temperature rise, axial stiffness and rotational accuracy. To overcome this issue, this study proposes a novel face-grinding spindle supported by a combined bearings, which include a water-lubricated hydrostatic thrust bearing and two rolling bearings with oil-air lubrication system. The thermal model for the proposed face-grinding spindle is established and the spindle thermal behavior is analyzed systematically. An experiment prototype of the face-grinding spindle is developed, and temperature rise of the spindle is detected to verify the thermal model. The result shows that the temperature rise of the proposed spindle can be decreased by the using of the water-lubricated hydrostatic thrust bearing. A comparative study between the two types of spindles shows that the proposed face-grinding spindle with the combined support has technical advantage of low temperature rise, large axial stiffness and low rotation accuracy, etc.

This paper aims to investigate the lubricating performance of the bubbly oil. Due to space limitation, the work is divided into two parts. Part 1 concluded that the bubbly oil under high shear rate has a lower viscosity than the non-aerated oil, and the air volume fraction can be adjusted conveniently to reach a high value. Based on this, in Part 2, we intend to explore the feasibility of using the bubbly oil in lubricating high-speed bearings. Here, we select a step thrust bearing as object and analyze its static characteristics under the bubbly oil lubrication. A test rig for the high-speed step thrust bearing was developed to measure the static characteristics of the bearing under the bubbly oil lubrication. The lubrication models for the hydrodynamic step thrust bearing were established to predict the bearing static characteristics. The results show that the static characteristics parameters of the bearing under the bubbly oil lubrication are less than those under the non-aerated oil lubrication, and the differences of static characteristics parameters of the bearing between the non-aerated oil lubrication and the bubbly oil one become larger with the increase of air volume fraction and the external load, especially at a higher speed.

Bubbly oil lubrication is a type of lubrication method that has a high potential for application. However, the lubricating performance of the bubbly oil has not been thoroughly considered. This paper aims to investigate the lubricating performance of the bubbly oil including the generation of the bubbly oil, viscosity characteristics of the bubbly oil, and the application study of the bubbly oil lubrication. Due to space limitation, the work is divided into two parts. Part 1 focuses on the generation method of the bubbly oil, observation of the bubbly oil, and the measurement of viscosity characteristics under a high shear rate. Part 2 focuses on the application study of the bubbly oil lubrication in high-speed bearing. A generation method for the bubbly oil was proposed by a combination of the dispersed-air method and the pressurized dissolution one. An experiment setup for generating the bubbly oil, an observation system for the bubbly oil, and a specially-designed viscometer for the bubbly oil were developed. The research results show that the generation method for the bubbly oil is of high efficiency and stability and the observation system is operational.

A biomechanical study, in which imaging modalities are used to strictly include patients with concurrent lateral ankle instability (LAI) and osteochondral lesions of the talus (OLT), is needed to demonstrate the static and dynamic ankle range of motion (ROM) restriction in these patients, and determine whether ankle ROM restriction can be corrected postoperatively.Eight patients with concurrent LAI and OLT treated with the arthroscopic modified Broström procedure and microfracture were recruited from June 2019 to January 2020. Patients were assessed using outcome scales, static ankle ROM, and a stair descent gait analysis for dynamic ankle ROM, a day prior to surgery and one year postoperatively. Eight healthy subjects were assessed using the same modalities upon recruitment. Operative outcomes and variables during stair descent were documented and compared among the preoperative, postoperative, and healthy groups. A curve analysis, one-dimensional statistical parametric mapping, was performed to compare the dynamic ankle kinematics and muscle activation curves over the entire normalised time series.The functional outcomes of patients with concurrent LAI and OLT were significantly worse than those of healthy subjects preoperatively, but were partially improved postoperatively. Patients had decreased static and dynamic ROM preoperatively, and static ROM did not significantly increase postoperatively (preoperative, 39.6 ± 11.3; postoperative, 44.9 ± 7.1; healthy, 52.0 ± 4.6; p = 0.021). Patients showed increased dynamic ankle flexion ROM (preoperative, 41.2 ± 11.6; postoperative, 53.6 ± 9.0; healthy, 53.9 ± 3.4; p = 0.012) postoperatively, as well as increased peroneus longus activation (preoperative, 35.8 ± 12.0; postoperative, 55.4 ± 25.1; healthy, 71.9 ± 13.4; p = 0.002) and muscle co-contraction of the tibialis anterior and peroneus longus (preoperative, 69.4 ± 23.4; postoperative, 88.4 ± 9.3; healthy, 66.2 ± 18.1; p = 0.045).Patients with concurrent LAI and OLT had decreased static and dynamic sagittal ankle ROM and altered neuromuscular activation patterns. The arthroscopic modified Broström procedure and microfracture did not significantly increase the static sagittal ankle ROM. However, the dynamic sagittal ankle ROM, peroneus longus activation and muscle co-contraction of the tibialis anterior and peroneus longus increased postoperatively.IV.

Machine tool spindle stiffness is a leading technical indicatoraffecting cutting ability. However, the stiffness of the machine tool spindle with fluid bearings has not been studied thoroughly. This paper proposes a new methodology for the spindle stiffness with fluid bearing including definition of the spindle nose stiffness, experimental method and calculation method for this stiffness. A motorized spindle with hydrodynamic water-lubricated spiral groove bearings developed in our laboratory is selected as an object, a theoretical and experimental investigation on the spindle nose stiffness is conducted. The result shows that the proposed experimental method can be utilized to measure the nose stiffness of spindle with the fluid bearings, meanwhile, the spindle stiffness can be obtained by simultaneously solving the rotor dynamic model and the fluid bearing dynamic model. The fluid bearing spindle stiffness depends strongly on the rotary speed and the external load. We expect an improvement for the experimental device by introducing another load device to apply a perturbation load with an any angle to the external load on the spindle nose.

Vanadium oxides (VOx) have been studied extensively for applications in thermochromic materials, electrochomics, and infrared detectors due to their unique phase transition characteristics. However, various vanadium oxide phases usually occur under different deposition conditions due to their particularly complex vanadium-oxygen system. In this research, V3O7, VO2(B), VO2(M), and V2O5 thin films were obtained as pure or mixed phases by controlling the substrate temperatures between 250 °C and 400 °C during magnetron sputtering. The microstructure and phase composition of vanadium oxide thin films were characterized and analyzed using X-ray diffraction and Raman spectroscopy. The phase evolution was dependent on the substrate temperature and could be clarified. Metastable V3O7 and VO2(B) phases were obtained at substrate temperatures of 250–300 °C, while stable VO2 and V2O5 phases were obtained at 350–400 °C. The surface morphology and optical properties of vanadium oxide thin films with different substrate temperatures were investigated in detail. Our results provide methods for transforming vanadium oxide phases under well controlled substrate temperatures.

Axial static stiffness is a main technical indicator for the ball screw feed drive system, and the elastic deformation outside the Hertz contact zone of the system affects its axial static stiffness. However, the influence of elastic deformation outside the Hertz contact zone on the axial stiffness has not been studied thoroughly. This study was to establish a flexible model of axial stiffness for the feeding system with considering the elastic deformation outside the Hertz contact zone. The axial stiffness of the feeding system was calculated using the proposed flexible model, and the model was verified by measuring the axial stiffness of the feeding system. The results show that the proposed flexible model can be more accurate compared with the conventional rigid model, and the method to analyze the elastic deformation outside the Hertz contact zone is practicable.

Water-lubricated bearings have attracted increasing attention in the field of high-speed machine tools for their low friction due to low viscosity. However, new problems, in particular, insufficient load capacity, are on the way. To the point, groove-textured journal bearing is adopted in this study. Aiming at investigating the effects of groove texture on high speed, water-lubricated, hydrodynamic journal bearing precisely, and thoroughly, three-dimensional computational fluid dynamic analyses considering cavitation and turbulence are undertaken to assess the tribological performances of the bearing. To reduce the amount of three-dimensional modeling and meshing work, mesh deformation is presented. The numerical results are compared with experiments to verify the validity of the present models and calculation procedures. Pressure distribution, load capacity, and friction of groove-textured water-lubricated journal bearing are analyzed with respect to operating conditions and geometric parameters. Comparisons between groove-textured water-lubricated journal bearing and smooth bearing are carried out to find out the influence of groove texture. It is found that the groove texture can achieve a remarkable improvement of load capacity at a smaller eccentricity ratio and higher rotary speed. The load capacity is affected by the combined effects of groove depth, width, and length. However, generally, the friction force of water-lubricated journal bearing is slightly influenced by groove texture. Results can provide theoretical guidance for the optimal design of groove-textured water-lubricated journal bearing under different operating parameters.

Journal bearing reaction is usually represented by a set of forces and moments concentrated at a single point. This single point support model cannot be utilized to describe the behavior of fairly long bearing. This technical brief proposes a multiple nodes model for the long bearing considering the distributed characteristics of bearing reaction and the effect of shaft deformation. The static behaviors of a rotor-bearing case with the proposed multiple nodes model are compared with those of the other three typical models. The result shows that the proposed multiple nodes model is practical for the analysis of the rotor system with a fairly long bearing, and the distributed effect of bearing reaction should be considered when the ratio of bearing length to the half of rotor length exceeds 0.2.

Airborne nano-scale particulate matter (nPM) exposure is a risk factor for neurological diseases. However, to date, there has been no comprehensive evaluation of ambient nPM's neurotoxicity. We examined the toxic effects of nPM on human neurons derived from induced pluripotent stem cells (iPSCs) at doses ranging from 0 to 200 μg/mL, and employed whole-genome RNA-sequencing in different dose groups to gain further insight into the neurotoxicity of ambient nPM. Our findings showed that nPM was absorbed by neurons, and induced a variety of toxic effects. The apical benchmark dose lower confidence bound (aBMDL) values of each effect endpoint were ranked as follows, in ascending order: mitochondrial membrane potential, neurite length, early apoptosis, cell viability. BMD analysis based on transcriptomic data revealed that the point of departure (PoD) of the 20 pathways with the lowest p-values (0.75 μg/mL), the top 20 upstream regulators (0.79 μg/mL) and the neurological diseases (0.77 μg/mL) could be appropriate for nPM neurotoxicity evaluation. The transcriptomic PoDs (tPoDs) were similar to apical PoDs (aPoDs) since their absolute fold differences were within 10-fold. Further analysis of the transcriptomic data revealed that nPM exposure could disturb the pathways related to ferroptosis, neurotransmitters, xenobiotic metabolism, etc., which might be critical in regulating nPM neurotoxicity. We also found that low-dose nPM induced cytokine signaling pathways, while high doses of nPM activated cell-cycle regulation and DNA repair pathways. Our results indicate that BMD modeling based on transcriptomic data could be useful in illustrating the neurotoxic mechanism, and also could be a promising method for evaluating the potential health risks of nPM.

A complete thermohydrodynamic lubrication model for pump-out spiral groove thrust bearings (SGTB) with cavitating flow is established based on two-phase flow and transport theory. Various effects (...

Background Efforts have been exerted to establish the correlation between objective variables and subjectively perceived ankle instability. Whether or not biomechanical parameters during stair descent can serve as potential assessment tools for perceived stability in people with unilateral ankle sprain history is unknown. Methods Twenty-four subjects with unilateral ankle sprain history were categorized into four groups according to the severity of perceived stability during stair descent. Kinematic and kinetic parameters during stair descent were obtained with a motion analysis system. Spearman's correlation coefficient (ρ) was utilized to test the correlation between the score of perceived stability during stair descent and biomechanical variables. Findings Subjects with increased perceived instability were likely to show increased ankle inversion (ρ = −0.46, p = .025) and increased ankle plantarflexion (ρ = 0.46, p = .025), with increased hip adduction (ρ = −0.43, p = .036), hip flexion (ρ = −0.56, p = .004), knee adduction (ρ = 0.45, p = .027), and knee flexion (ρ = −0.44, p = .031). No significant correlation was detected between kinetic variables and perceived stability. Interpretation Sagittal and coronal plane motions of the ankle might require rehabilitative intervention to produce improved self-reported outcomes. Kinematic assessment during stair descent can aid in the quantification of subjective ankle instability.

To meet the needs of corrosion resistance and electrically conductivity for metallic bipolar plates that are employed in proton exchange membrane fuel cells (PEMFCs), a TiSiN nanocomposite coating was fabricated on to a Ti–6Al–4V substrate using reactive sputter-deposition through the double cathode glow discharge plasma technique. The microstructure of the TiSiN coating comprised nanocrystallite TiN grains embedded in an amorphous Si3N4 matrix. Electrochemical measurements were employed to investigate the corrosion behavior of the TiSiN coating in the simulated operating environments of a PEMFC, specifically 0.5 M H2SO4 solution containing different HF concentrations (namely 2, 4 and 6 ppm) at 70 °C pumped with H2 at the anode and air at the cathode. With increasing HF concentration, a higher corrosion current density and lower corrosion potential were observed from both the coating and the uncoated substrate, indicating that the addition of HF accelerated their corrosion rates under these conditions. Compared to the uncoated substrate, the TiSiN coating showed a markedly higher corrosion resistance at all HF concentrations. The passive film that formed on the TiSiN coating, with a resistance of the order of magnitude of ~107 Ω cm2, displayed good electrochemical stability and was less affected by changes in HF concentration. For the TiSiN coating, the values of interfacial contact resistance (ICR) were 14.7 mΩ cm−2 and 18.3 mΩ cm−2, respectively, before and after 2.5 h potentiostatic polarization with 6 ppm HF under cathodic conditions under a compaction pressure of 140 N cm−2. Both values are much lower than those for the bare substrate. Moreover, the TiSiN coating was shown to improve the hydrophobicity of Ti–6Al–4V that would help facilitate water management in the PEMFC operating environment. This coating, which exhibited excellent corrosion resistance, electro-conductivity and hydrophobicity, is therefore a promising material for protecting metallic bipolar plates from corrosive attack.

The support is a key factor affecting performance of face-grinding spindle. However, advantage of traditional rolling element bearing is not highlighted when it is for large-size face grinding. This technical brief aims to develop a combined support for the face-grinding spindle consisting of a water-lubricated hydrostatic thrust bearing and two types of radial rolling bearings, and the flexible rotor dynamics of the spindle with the combined support is analyzed using the modified transfer matrix method. The results show that the rotational stiffness of water-lubricated hydrostatic thrust bearing can increase the radial stiffness of the face-grinding spindle, so the small-size rolling bearings can be utilized as the radial support for the spindle by aid of such rotational stiffness. A comparative study of comprehensive performance between the spindle supported by rolling bearings and the replacement spindle designed with our proposed combined support shows that the proposed one has technical advantage of large axial load-carrying capacity, low frictional power loss, low temperature rise, etc.

To summarize the strategy of using extracorporeal membrane oxygenation (ECMO) support during lung transplantation from 2 coronavirus disease 2019 (COVID-19) with end-stage respiratory failure.Two COVID-19 with end-stage respiratory failure patients were admitted to Nanjing Medical University Affiliated Wuxi People's Hospital in March 2020. As the homoeostasis and vital signs could not be maintained in balance by conventional treatments, lung transplantations were performed. Here, detail information about combined application of peripheral veno-venous ECMO (VV-ECMO) and central veno-arterial ECMO (CVA-ECMO) during the operation will be discussed.Case 1: 59 years old, 172 cm height, 72 kg weight, who received mechanical ventilation for 22 days, tracheotomy tube for 17 days, and VV-ECMO support for 7 days. Case 2: 72 years old, 178 cm height, 71 kg weight, who received mechanical ventilation for 19 days, tracheotomy tube for 17 days, and VV-ECMO support for 18 days. As both of them have severe COVID-19-associated respiratory failure, and the recovery was determined to be unlikely, lung transplantations were performed. Severe pulmonary arterial hypertension (PAH) and cardiac insufficiency were found during the operation. Based on preoperative VV-ECMO, CVA-ECMO was added. The concomitant use of peripheral VV-ECMO and CVA-ECMO offered satisfied intraoperative oxygenation and cardiopulmonary status,the operations run smoothly, and the CVA-ECMO was successfully removed, no ECMO-related complications occurred.The combined use of VV-ECMO and CVA-ECMO is an optimal strategy in the end-stage ARDS patients with severe PAH and cardiac insufficiency, which can offer benefits on respiratory and cardiac functions simultaneously, and ensure surgery safety.

Previous studies on the kinematics of patients with chronic ankle instability (CAI) that did not incorporate MRI and arthroscopic assessment could not differentiate between patients with CAI without osteochondral lesion of the talus (OLT) and patients with CAI and OLT and have thus presented contradictory results.This study aimed to investigate the kinematic and electromyographic differences between patients with and without OLT.Sixteen subjects with CAI (eight without OLT and eight with OLT confirmed through MRI and arthroscopic assessment) and eight healthy subjects underwent gait analysis in a stair descent setting. The three groups' patient-reported outcomes; ankle joint range of motion in flexion, inversion and rotation; and muscle activation of the peroneus, tibialis anterior, and gastrocnemius during a gait cycle were analyzed and compared. A curve analysis, namely, one-dimensional statistical parametric mapping, was performed to compare the dynamic ankle kinematics and muscle activation curves over the entire normalized time series.The patients with and without OLT had no difference in patient-reported outcomes. The maximal ankle plantarflexion of the patients without OLT and the healthy subjects was significantly larger than that of patients with OLT (p = 0.005). The maximal ankle internal rotation of patients without OLT was significantly larger than that of patients with OLT (p = 0.048). The peroneal activation during 0-6% of the gait cycle of patients with OLT was reduced compared with the healthy subjects.Patients with CAI and OLT and patients with CAI without OLT have no difference in patient-reported outcomes, but patients with OLT can be differentiated using the post-initial-contact peroneal activation deficit and the restriction of ankle plantarflexion and internal rotation during stair descent. These variables can be utilized to monitor the function of patients with CAI and their possibility of developing OLT.

The dynamic network biomarkers (DNBs) are designed to identify the tipping point and specific molecules in initiation of PM

In order to study the dynamic position accuracy of bottom dead point (BDP) for multilink high-speed precision presses (MHSPPs), it’s essential to develop a dynamic model of planar multilink mechanism with clearance and spindle-bearing structure. Traditional models always neglect the effect of thermal characteristics of spindle-bearing structure, which reduces the prediction accuracy of dynamic model for multilink transmission mechanisms. To overcome the shortcomings of the previous models, a thermal network model (TNM) of the crankshaft-bearing system is established firstly considering the effects of thermal contact resistance and variable stiffness of bearing concerning the temperature rise. Then, dynamic model of the crankshaft-bearing system is built through the finite element method, which includes rigid disk, Timoshenko beam and quasi-statics model of ACBB. On this basis, an improved dynamic model of planar flexible multilink mechanism with clearance considering the thermal-mechanical coupling effect of the crankshaft-bearing structure is developed and the corresponding dynamic error dimension chain between slider and crankshaft is constructed in this work. Compared to the simulation from traditional models, the simulated slider’s BPD position error from the improved model agrees better with experimental data, which verifies the correctness of the proposed model. It’s demonstrated that the punching force and thermally induced variable stiffness of bearing lead to a significant increase of slider’s BDP position error, which reduces the machining precision of MHSPP. Furthermore, the influence of crankshaft speed, contact angle of bearing and clearance size on the slider’s BDP position error is also investigated.

To investigate the main postoperative complications, causes of death and the risk factors for survival in patient with benign end-stage lung diseases within 1 year after lung transplantation.A retrospective analysis was conducted to collect the clinical data of 200 patients with benign end-stage lung disease who underwent lung transplantation admitted to Wuxi People's Hospital Affiliated to Nanjing Medical University from May 2017 to October 2018. The main postoperative complications, survival and causes of death within 1 year after operation were analyzed. The Kaplan-Meier method was used to plot survival curves, and the Log-Rank test was used to compare the influence of factors, including recipient's gender, use of marginal donor lung, primary disease, preoperative combination of moderate to severe pulmonary hypertension (PAH), intraoperative extracorporeal membrane oxygenation (ECMO) support, surgical methods, intraoperative massive blood loss, postoperative complications [infection, primary graft dysfunction (PGD), acute rejection], on 1-year survival in patients who underwent lung transplantation. The multivariate Cox proportional hazards regression model was used to evaluate the risk factors of death within 1 year after lung transplantation.Two hundred patients underwent successful lung transplantation. The major postoperative complications within 1 year after transplantation included infection in 131 patients, PGD in 20 patients, acute rejection in 57 patients, anastomotic complication in 26 patients and others (new onset diabetes, osteoporosis, etc.) in 53 patients. The 3-month, 6-month, and 1-year postoperative cumulative survival rates were 81.5%, 80.0% and 77.5%, respectively. Forty-five patients died during 1 year after operation, among whom 14 died of infection, 7 died of PGD, 8 died of acute rejection, 4 died of anastomotic complication, 3 died of cardio-cerebrovascular accident, 3 died of multiple organ failure, 2 died of respiratory failure and 4 died of other causes (traffic accident, etc.). The Kaplan-Meier survival analysis showed that recipient's gender, idiopathic pulmonary fibrosis (IPF) as the primary disease, preoperative combination of moderate and severe PAH, intraoperative ECMO support, intraoperative massive blood loss, postoperative complications (infection, PGD, acute rejection) were influencing factors for postoperative 1-year survival rate. The multivariate Cox regression model showed that male was the protective factor [hazard ratio (HR) = 0.481, 95% confidence interval (95%CI) was 0.244-0.947, P = 0.034], IPF as the primary disease (HR = 2.667, 95%CI was 1.222-5.848, P = 0.014), intraoperative use of ECMO support (HR = 1.538, 95%CI was 0.787-3.012, P = 0.028), massive blood loss during surgery (HR = 2.026, 95%CI was 0.976-4.205, P = 0.045) and postoperative infection (HR = 3.138, 95%CI was 1.294-7.608, P = 0.011), PGD (HR = 1.604, 95%CI was 0.464-5.539, P = 0.004), and acute rejection (HR = 1.897, 95%CI was 0.791-4.552, P = 0.015) were the independent risk factors for death within 1 year after transplantation.One-year survival rates after lung transplantation are affected by recipient's gender, primary disease, preoperative combination of moderate and severe PAH, intraoperative ECMO support, intraoperative massive blood loss, and postoperative complications (infection, PGD, acute rejection). The male is the protective factor, while IPF as the primary disease, intraoperative ECMO support, massive blood loss during surgery and postoperative complications (infection, PGD, acute rejection) are independent risk factors for death within 1 year after lung transplantation.

Background: To explore the correlation between the preoperative systemic immune inflammation index (SII) and the prognosis of patients with gastric carcinoma (GC).Methods: The clinical data of 771 GC patients surgically treated in the Department of Gastrointestinal Surgery, Qinghai University Affiliated Hospital from June 2010 to June 2015 were retrospectively analyzed, and their preoperative SII was calculated. The optimal cut-off value of preoperative SII was determined using the receiver operating characteristic (ROC) curve, the confounding factors between the two groups were eliminated using the propensity score matching (PSM) method, and the correlation between preoperative SII and clinicopathological characteristics was assessed by chi-square test. Moreover, the overall survival was calculated using Kaplan-Meier method, the survival curve was plotted, and log-rank test was performed for the significance analysis between the curves. Univariate and multivariate analyses were also conducted using the Cox proportional hazards model.Results: It was determined by the ROC curve that the optimal cut-off value of preoperative SII was 489.52, based on which 771 GC patients were divided into high SII (H-SII) group and low SII (L-SII) group, followed by PSM in the two groups. The results of Kaplan-Meier analysis showed that before and after PSM, the postoperative 1-, 3- and 5-year survival rates in L-SII group were superior to those in H-SII group, and the overall survival rate had a statistically significant difference between the two groups (PConclusions: Preoperative SII is an independent risk factor for the prognosis of GC patients. The increase in preoperative SII in peripheral blood indicates a worse prognosis.

Water-lubricated hydrodynamic spiral groove bearing is a potential support way for high-speed rotary machine, but the frictional power loss of the bearing will increase with the rotatory speed. Surface texture processing should be an effective technical means to decrease the friction power loss, and other static characteristics of the bearing will be affected by the such textural surface. However, the static characteristics of water-lubricated textured spiral groove thrust bearing have not been thoroughly considered. This article aims to establish the theoretical model for the water-lubricated textured spiral groove thrust bearing under laminar cavitating flow, and field distribution and static characteristics of the bearing are analyzed using the model. A verified test indicates that the theoretical simulation agrees with the experimental value. The result shows that, with consideration of texture effect, the friction torque of the bearing is reduced, there exists an optimal texture parameter for a given film thickness, under which the bearing has the maximum load-carrying capacity, no obvious change rule is found for the volume flowrate; with consideration of the cavitation effect, the load-carrying capacity of the bearing is increased, while the volume flow and the friction torque are slightly affected. The model developed in this study lays a solid foundation for the design of the water-lubricated textured spiral groove bearing.

A ZrC nanoceramic coating was prepared on the bare 316 stainless steel for improving the cavitation erosion resistance by the double glow discharge sputter technique. The phase constitution and surface microstructure of the ZrC nanoceramic coating were characterized by X-ray diffraction, scanning electron microscope, and transmission electron microscopy. A 10-µm-thick ZrC nanoceramic coating exhibited equiaxed grains with an average grain size of 9 nm. The adhesion strength and mechanical properties for the ZrC nanoceramic coating were evaluated by scratch test and nanoindentation. The hardness value of the ZrC nanoceramic coating was about four times that of the uncoated 316 stainless steel. The cavitation erosion behavior of the ZrC nanoceramic coating in tap water was characterized by the combination of an ultrasonic vibration system with an electrochemical workstation. The volume loss, erosion depth, scanning electron microscope morphology, and electrochemical test were adopted to assess the surface damage of the ZrC nanoceramic coating. The results show that the volume loss of the ZrC nanoceramic coating is 0.53 mm3, which is only 46% of the 316 stainless steel (1.14 mm3) after cavitation test, and erosion damage of the ZrC nanoceramic coating is significantly decreased as compared to the uncoated 316 stainless steel. The electrochemical test results also indicate that the ZrC nanoceramic coating shows higher corrosion resistance than the 316 stainless steel under cavitation erosion condition. Thus, the ZrC nanoceramic coating can be adopted to enhance the cavitation erosion resistance of the 316 stainless steel.

The effect of Ag additions on the structural, mechanical and thermodynamic properties of α-Nb5Si3 is systematically investigated using the first-principles calculations based on density functional theory. The calculated formation enthalpies show that when Nb atoms in α-Nb5Si3 are replaced by one and two Ag atoms, Ag atoms prefer Nb4c sites rather than Nb16l sites. With increasing concentration of Ag atoms, the elastic moduli and theoretical Vickers hardness of the α-(Nb1-xAgx)5Si3 compounds decrease, while they become more ductile. Ag additions slightly raise the mechanical anisotropies of α-(Nb1-xAgx)5Si3 compounds and increases the linear thermal expansion coefficients of the α-(Nb1-xAgx)5Si3 compounds along the c and a axes, with a decrease in the αc/αa ratios. Finally, the anisotropy of acoustic velocities and Debye temperatures for the α-(Nb1-xAgx)5Si3 compounds were also calculated.

The purpose of this paper is to study the effect of chemical heat treatments on cavitation erosion resistance of the 304 stainless steel. Three types of diffusion layers are prepared on the 304 stainless steel using gas nitriding, gas carburizing, and carbonitriding treatments. Phase composition and surface microstructure of the diffusion layers are characterized by X-ray diffraction and scanning electron microscopy. And then, the cavitation erosion behavior of the diffusion layers are tested and compared with the one of the 304 stainless steel. The cavitation test is performed in an ultrasonic vibration system integrated with an electrochemical workstation. The mass loss, scanning electron microscopic morphology, and electrochemical test are adopted to assess the surface damage of the diffusion layers. A measurement for the mechanical properties of the diffusion layers shows that the hardness and the elastic modulus of the gas nitrided diffusion layer, carbonitrided diffusion layer, carburized diffusion layer, and 304 stainless steel are 5.3 GPa and 260 GPa, 4.2 GPa and 236 GPa, 4.0 GPa and 210 GPa, 2.5 GPa and 193 GPa, respectively. A cavitation erosion test of 14 h shows that mass loss of the gas nitrided diffusion layer, carbonitrided diffusion layer, carburized diffusion layer, and 304 stainless steel is 5.19 mg, 8.97 mg, 14.37 mg, and 6.62 mg, respectively. The electrochemical test results also indicate that the gas nitrided diffusion layer has a higher corrosion resistance than the carburized diffusion layer, carbonitrided diffusion layer, and stainless steel under cavitation erosion condition. As a conclusion, the gas nitrided diffusion layer is capable of enhancing the cavitation erosion resistance of the stainless steel, while the carburized diffusion layer and carbonitrided diffusion layer increases the mass loss of the stainless steel under cavitation erosion condition.

In this study, a β-Ta2O5 coating was deposited onto a Ti–6Al–4V substrate using a double-cathode glow discharge plasma technique. The hardness and elastic modulus values of the β-Ta2O5 coating were...

This technical note aims to reduce friction power loss of flywheel energy storage system (FESS) supported by hydrodynamic spiral groove bearing and permanent magnetic bearing (PMB). An approach is proposed to fabricate the spiral groove bearing using polytetrafluoroethylene (PTFE) composite. A test rig is developed to test tribological properties of the spiral groove PTFE bearings. Also, two PTFE composites (C-PTFE: 80 vol.% PTFE filled with 20 vol.% graphite; C-Cu-PTFE 50 vol.% PTFE filled with 20 vol.% graphite and 30 vol.% copper powder) are tested. Results show that the friction power losses of the C-PTFE and C-Cu-PTFE bearings are lower than that of the traditional albronze (CuAl) bearing in the whole speed range. In addition, the spiral groove PTFE bearings show an excellent friction-reducing property under boundary or mixed lubrication condition. Finally, a case study is given to show the spiral groove PTFE bearing is capable of reducing the friction power loss of the FESS.

A misaligned thermohydrodynamic (THD) model considering turbulent-flow is presented to predict the performance of water-lubricated hydrodynamic journal bearing (WHJB). The load capacity, frictional power loss, flow rate, mid-plane pressure distribution, translational, tilting and coupled translational-tilting dynamic coefficients versus the rotary speed, eccentricity ratio and tilting angle are analyzed; quantitative comparisons between models considering and without considering turbulent, THD and misaligned effects are given. Results show that the turbulence improves the load capacity while the THD effect decreases it; the THD effect reduces the frictional power loss significantly while the turbulent effect is weak; at large rotary speed and eccentricity ratio, the THD and turbulent effects on the dynamic coefficients should be fully considered at both of aligned and misaligned conditions.

To investigate the effects of Al alloying on the erosion-corrosion resistance of β-Ta5Si3, both a β-Ta5Si3 coating and an Al-alloyed β-Ta5(Si0.83Al0.17)3 coating were synthesized on a 316 substrate by the double cathode glow discharge technique. The phase constitution, composition and microstructure of the two coatings were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The two coatings were composed of nearly rounded D8m-β-Ta5Si3 grains with an average size of ∼4 nm, and after the addition of Al, the preferred growth orientation for the β-Ta5Si3 coating changed from (4 0 0) to (0 0 2). The hardness, elastic modulus and contact damage resistance of the coatings were measured using a nanoindentation tester. The results showed that Al alloying improved the contact damage resistance of β-Ta5Si3 with only a slight decrease in hardness. The erosion-corrosion behavior of the two coatings was performed in a 3.5 wt% NaCl solution containing a 12 wt% concentration of silica sand under two phase slurry flow condition and in a 3.5 wt% NaCl solution under ultrasonic cavitation erosion conditions. This revealed that the Al alloyed β-Ta5Si3 has a higher resistance to both erosion-corrosion and ultrasonic cavitation erosion as compared to the binary β-Ta5Si3 coating.

Background Selective Dorsal Rhizotomy (SDR) guided by our modified protocol can decrease spasticity in certain muscles. This study aimed to investigate gait parameters changes in cerebral palsy (CP) with focal spasticity after SDR in short-term follow-up. Methods CP classified as Gross Motor Function Classification System (GMFCS) level Ⅰ and Ⅱ who underwent SDR were included. Changes of spasticity, gait parameters and gait deviation index (GDI) were retrospectively reviewed. Results This study contained 26 individuals with 44 affected and 8 intact lower limbs (4 monoplegia, 4 hemiplegia and 18 diplegia). Mean age was 5.7 ± 1.9 years-old and follow-up duration was 9.9 ± 6.6 months. After SDR, average spasticity of 108 target muscles decreased from 2.9 ± 0.8 to 1.8 ± 0.6 in Modified Ashworth Scale (MAS). Kinematic curves changed after the surgery in sagittal and transverse plane in affected sides, further investigation showed improvements in ankle and knee. No changes were found in temporal-spatial parameters except decrease in cadence in affected sides. GDI improved significantly in affected limbs. Conclusion In short-term follow up, the new-protocol-guiding SDR can lower focal spasticity, GA showed improvements in kinematic parameters and GDI. Longer follow-up duration is needed to clarify the long-term outcome.