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In the aerospace field, titanium alloys are extensively used for the airframe and engine parts to improve aircraft fuel consumption. Drilling through these parts in a single-shot process to produce high quality holes is challenging. During drilling, high temperatures are generated owing to the friction between the cutting tool and workpiece, causing the process becomes inefficient in terms of tool life and surface quality. To reduce the temperature produced in the cutting zone, different types of cooling techniques during drilling have been used by researchers. In this study, the feasibility of quarry dust suspension as coolant in drilling of titanium alloy was performed. The effects of different concentrations of quarry dust on surface roughness, thrust force, and burr formation were evaluated, and their machining performances were compared with those obtained using aluminium oxide suspension. Before the experiments, both suspensions were prepared by dispersing quarry dust and aluminium oxide particles into deionised water at various concentrations ranging from 0 wt% to 0.10 wt%. Results indicated that by using 0.06 wt% of quarry dust suspension, thrust force and surface roughness showed an improvement by 8.31% and 18.29%, respectively, compared with those of aluminium oxide suspension at the same concentration. The burr height formed at the drilled holes using 0.06 wt% of quarry dust was also lower than that formed with aluminium oxide suspension at the same concentration.

The present study focused on the surface modification of aluminum 6061 by using electrical discharge coating (EDC) with powder suspension. The effects of peak current (Ip) and pulse on time (Ton) on the coating layer thickness were investigated. This study used Tungsten powder as an additive and mixed it with the kerosene oil and surfactant Span 83. The results indicated that peak current and pulse on-time significantly affected the coating layer thickness. The thinnest coating layer was observed at 3A, 150 µs, while the thickest coating layer with an average value of 17.239 µm was obtained at parameter 4A and 250 µs. In conclusion, the high value of peak current and longer pulse duration on time increased the thickness of the coating layer.

Micro ultrasonic machining (micro-USM) is an unconventional micromachining technology that has capability to fabricate high aspect ratio micro-holes, intricate shapes and features on various hard and brittle materials. The material removal in USM is based on brittle fracture of work materials. The mechanical properties and fracture behaviour are different for varied hard and brittle materials, which would make a big difference in the processing capability of micro-USM. To study the processing capability of USM and exploit its potential, the material removal of work materials, wear of abrasive particles and wear of machining tools in USM of three typical hard and brittle materials including float glass, alumina, and silicon carbide were investigated in this work. Both smoothed particle hydrodynamics (SPH) simulations and verification experiments were conducted. The material removal rate is found to decrease in the order of glass, alumina, and silicon carbide, which can be well explained by the simulation results that cracking of glass is faster and larger compared to the other materials. Correspondingly, the tool wear rate also dropped significantly thanks to the faster material removal, and a formation of concavity on the tool tip center due to intensive wear was prevented. The SPH model is proved useful for studying USM of different hard and brittle materials, and capable of predicting the machining performance.

Inositol-requiring enzyme 1 (IRE1) is an evolutionarily conserved sensor of endoplasmic reticulum (ER) stress and mediates a key branch of the unfolded protein response in eukaryotic cells. It is an ER-resident transmembrane protein that possesses Ser/Thr protein kinase and endoribonuclease (RNase) activities in its cytoplasmic region. IRE1 is activated through dimerization/oligomerization and autophosphorylation at multiple sites, acting through its RNase activity to restore the functional capacity of the ER. However, it remains poorly defined in vivo how the autophosphorylation events of endogenous IRE1 govern its dynamic activation and functional output. Here, we generated a mouse model harboring a S724A knock-in mutation (Ern1

BackgroundMyelin oligodendrocyte glycoprotein-antibody (MOG-ab)-associated disease (MOGAD) has highly heterogenous clinical and imaging presentations, in which encephalitis is an important phenotype. In recent years, some atypical presentations in MOG-ab-associated encephalitis (MOG-E) have been increasingly reported but have not yet been described well. The aim of the study was to describe the clinical and imaging features of patients with MOG-E in our center. Atypical phenotypes would be reported, which is expected to expand the spectrum of MOGAD.MethodsWe reviewed medical records of 59 patients with MOGAD diagnosed in our center and identified cases who had ever experienced encephalitic symptoms. Three hundred ten patients with autoimmune encephalitis (AE) were also reviewed, and cases with positive MOG-ab were identified. Besides, patients with chronically progressive encephalitis were identified from 13 MOG-E and 310 AE patients. We collected demographic, clinical, laboratory, radiological, and outcome data to explore clinical and imaging characteristics in MOG-E, especially in the atypical phenotype of chronically progressive encephalitis.ResultsWe identified 13 patients (7 males, 6 females) with MOG-E. The median age at onset was 33 years (range 13~62 years). Most (9/13, 69.2%) of patients showed acute or subacute onset of encephalitic symptoms. Brain MRI abnormalities were observed in all patients. The most common lesion locations on MRI were cortical/subcortical (11/13, 84.6%), deep/periventricular white matter (10/13, 76.9%) and corpus callosum (4/13, 30.8%). Brain MRI patterns were categorized into four phenotypes. The most common pattern was cortical encephalitis with leptomeningeal enhancement/brain atrophy (10/13, 76.9%). Eight (8/13, 61.5%) patients had a good response to immunotherapy. Four (4/13, 30.8%) patients with chronically progressive course were identified from MOG-E cohort. They showed leukodystrophy-like pattern, multifocal hazy lesions, or cortical encephalitis on MRI. With immunotherapy, they only showed mild or no improvement. We also identified four (4/310, 1.3%) patients with chronically progressive course from AE cohort. They had better outcomes than counterparts in MOG-E.ConclusionsThis study demonstrates that encephalitic presentations in MOGAD had complex clinical patterns. Chronically progressive encephalitis may be a new phenotype of MOGAD. We recommend to test MOG-ab in subacute and chronic progressive dementia with leukodystrophy-like MRI lesions.

Sliding bearings are critical components of the internal combustion engine. Friction and wear occur in the contact area between the shaft and the bearing. Significant wear can occur in poor working conditions or after a long service time, leading to the failure of the sliding bearing and affecting the reliability of the machinery. It is essential to investigate the wear performance of sliding bearings, understand their wear mechanism, predict their service life, and select wear-resistant materials and surface treatments. This paper reviews the current status and prospects of sliding bearing wear research, focusing on the classification of sliding bearing wear tests, wear testing machines, wear test research, wear prediction models, and future research prospects.

Di-(2-ethylhexyl) phthalate (DEHP) is a typical endocrine-disrupting chemical (EDC) that can increase the risk of central nervous system disease. This study aimed to investigate the in vitro and in vivo effects of DEHP exposure on GDNF secretion and the underlying mechanisms. Pregnant Wistar rats were randomly assigned into four groups and administered 0, 30, 300, or 750 mg/kg DEHP daily by oral gavage. In addition, primary astrocytes were exposed to mono-(2-ethylhexyl) phthalate (MEHP), the main metabolite of DEHP. Our results showed that DEHP exposure reduced GDNF levels and downregulated the ERK/c-fos signaling pathway in the cerebral cortex of male, but not female, offspring. Moreover, exogenous estrogen could overcome the decreased GDNF levels in astrocytes caused by MEHP exposure. MEHP also decreased p300 levels and downregulated the ERK/c-fos signaling pathway in primary astrocytes. Honokiol restored GDNF levels following MEHP exposure by activating the ERK/c-fos signaling pathway, while the inhibitor U0126 further reduced the GDNF levels. These results suggested that DEHP exposure could interfere with the normal effects of estrogen in the brain and downregulate the ERK/c-fos signaling pathway to decrease the GDNF secretion from astrocytes in the cerebral cortex.

In ultrasonic machining (USM), a mirror-like surface cannot be readily obtained on hard and brittle materials owing to easily generated microcracks. This drawback greatly limits the utilisation of USM as a finish machining technology. Therefore, minimizing the crack size or even eliminating the cracks is necessary to improve surface quality. In this study, fine abrasive particles are first applied to minimize the crack size during USM. Material removal efficiency and surface quality are then evaluated. However, crack formation during this process is unavoidable, and microcracks left on the machined surface cannot be completely removed by merely decreasing the particle size. In addition, minimizing the particle size is not beneficial to maintaining a desired machining rate. Therefore, a new method to repair the cracks by laser irradiation is proposed. The USM machined surfaces of glass plates are irradiated by a carbon dioxide laser at a wavelength of 10.6 μm to repair the cracks because glass has a high absorption coefficient at this wavelength. The temperature field generated during this process is evaluated using the finite element method. Simulation and experimental results demonstrate that the scanning speed of the laser beam has a considerable effect on the temperature increase, thereby influencing the repair result accordingly. Finally, a smoothed surface without cracks is obtained under a scanning speed of 300 mm/min and 5 W power. The combination of micro-USM and laser irradiation exhibits great potential for fabricating various micro-shapes and structures on hard and brittle materials, such as glass with high efficiency, high form precision and high surface quality.

The spectrum of anti-contactin-associated protein-like 2 (CASPR2) antibody-associated disease is expanding and the involvement of cerebellum was reported in the past few years. We report a 45-year-old male with chronically progressive cerebellar ataxia. CASPR2 antibodies were detected in his serum and cerebellar atrophy was observed on MRI. His symptoms improved prominently with steroids and intravenous immunoglobulins. 23 cases with CASPR2 antibodies and cerebellar ataxia were identified from previous publications. Most of patients showed acute or subacute onset with other typical presentations of anti-CASPR2 antibody-associated disease, such as limbic encephalitis. Immunotherapy was effective in the majority of patients.

This paper focuses on the fatigue reliability analysis and the development of a new life model of reliability and crack growth mechanisms in FV520B-I (high strength martensitic-type stainless steels) in the very-high cycle fatigue (VHCF) regime, which haven&rsquo, t been studied well. First, the fatigue test was carried out to clarify the fatigue failure mechanism in the very-high cycle regime. Based on the test results and fatigue reliability theory, the fatigue life distribution and P-S-N curves were modeled. A new fatigue life evaluation model for FV520B-I is proposed according to the fracture mechanics and classic life evaluation method. With the comprehensive application of P-S-N curves and a new proposed fatigue life evaluation model, a new assumption of a P-Sc-N curve is developed and verified, to quantitatively express the relationship between fatigue life, reliability and fatigue cracking. This is novel and valuable for further fatigue study of FV520B-I.

The indoor–outdoor (IO) status of mobile devices is fundamental information for various smart city applications. In this paper, we present NeuralIO, a neural-network-based method for dealing with the IO detection problem for smartphones. Multimodal data from various sensors on a smartphone are fused through neural network models to determine the IO status. A data set containing more than one million labeled samples is then constructed. We test the performance of an early fusion scheme in various settings. NeuralIO achieves an accuracy above 98% in 10-fold cross-validation and an accuracy above 90% in a real-world test.

As a particular important factor in UltraSonic Machining (USM), the tool wear largely affects the material removal process and accordingly influences the machining performance. Although a number of experiments were conducted to monitor and measure the tool wear during USM in previous works, the nature of the tool wear mechanism and its relation to material removal have not been totally understood. Therefore, both simulations and experiments were conducted for studying the influence of tool wear on material removal in this work. Three different tool materials i.e. 304 stainless steel, 1045 carbon steel, and tungsten carbide were used. A numerical simulation model utilizing both Smoothed Particle Hydrodynamics (SPH) meshfree method and Finite Element Method (FEM) was built first to predict tool deformation and fractures of workpiece and abrasive particles. Experiments were then conducted to verify the simulation results. It was found that using tool materials possessing a high flexibility such as 304 stainless steel can slow down the wear of abrasive particles and improve the material removal efficiency. Additionally, work hardening was confirmed to occur in 304 stainless steel and accordingly suppressed the tool wear. On the other hand, when using tungsten carbide as the tool material, even though the tool wear was small due to the high hardness, the abrasive particles were abraded seriously and the material removal efficiency was lowest. Finally, the relation between the material removal and the tool wear was discussed based on these results.

UltraSonic Machining (USM) shows potentialities in many manufacturing uses including fabricating structures of any shapes on hard and brittle materials. However, the nature of the mechanism of this process is still not clear. Crack generation for material removal and wear mechanism of abrasive particles and machining tools have not been thoroughly understood. Therefore, this paper presents a new method for studying USM by using a numerical simulation model built with both Smoothed Particle Hydrodynamics (SPH) meshfree method and Finite Element Method (FEM). Two main particle shapes: cubical and spherical shapes filled by SiC and Al2O3 materials were incorporated in the simulation models for studying the fracture process of the workpiece and abrasive particles. Hole drilling experiments by USM were also conducted to validate the simulation results. Both of the experimental and simulation results suggest that hard abrasive particles possessing spherical shapes resist wear better and it improves the material removal efficiency. However, the surface quality was inverse, large cracks were found to be remaining on the machined surfaces after etching. The best machining result was obtained with spherical Al2O3 abrasive particles in this work. The tool feed rate can be up to 40 μm/s, the cracks were less than 5 μm and 4 μm in depth for bottom and wall surfaces after etching, and the tool wear was the lowest. These results help us better understanding the nature of USM and provide technological indicators for selecting suitable process parameters for improving the machining performance.

Hard coatings are extensively required in industry for protecting mechanical/structural parts that withstand extremely high temperature, stress, chemical corrosion, and other hostile environments. Electrical discharge coating (EDC) is an emerging surface modification technology to produce such hard coatings by using electrical discharges to coat a layer of material on workpiece surface to modify and enhance the surface characteristics or create new surface functions. This paper presents a comprehensive overview of EDC technologies for various materials, and summarises the types and key parameters of EDC processes as well as the characteristics of resulting coatings. It provides a systematic summary of the fundamentals and key features of the EDC processes, as well as its applications and future trends.

Background Cervical spinal cord atrophy (CSCA), which partly reflects the axonal loss in the spinal cord, is increasingly recognized as a valuable predictor of disease outcome. However, inconsistent results have been reported regarding the correlation of CSCA and clinical disability in multiple sclerosis (MS). The aim of this meta-analysis was to synthesize the available data obtained from 3.0-Tesla (3T) MRI scanners and to explore the relationship between CSCA and scores on the Expanded Disability Status Scale (EDSS). Methods We searched PubMed, Embase, and Web of Science for articles published from the database inception to February 1, 2019. The quality of the articles was assessed according to a quality evaluation checklist which was created based on the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. We conducted a meta-analysis of the correlation between EDSS scores and CSCA at 3T MRI in MS. Results Twenty-two eligible studies involving 1933 participants were incorporated into our meta-analysis. Our results demonstrated that CSCA was negatively and moderately correlated with EDSS scores (rs = -0.42, 95% CI: -0.51 to -0.32; p Conclusions The correlation between CSCA and EDSS scores was significant but moderate. We encourage more studies using reliable and consistent methods to explore whether CSCA is suitable as a predictor for MS progression.

Powder-based layered Additive Manufacturing (AM) techniques lead to high surface roughness, due to the balling and partial melting of powders, which cannot satisfy the requirements of design and practical use. Consequently, until there is a significant step-change in the resolution of AM technology, finishing processes will be a necessary step in the additive manufacturing process. In this work, ultrasonic abrasive polishing experiments are conducted with the aim of improving the surface quality of additive manufactured components. The roles of cavitation bubbles and abrasive particles in material removal are discussed. The impact action of abrasive particles is simulated using the Smoothed Particle Hydrodynamics (SPH) method. The effects of ultrasonic output power and the concentration of abrasive suspension on machining characteristics are also examined. It is found that the cavitation bubble collapse in ultrasonic polishing can remove the partially melted structures efficiently, and further roughness improvement could be obtained using the micro-cut and impact of abrasive particles in the slurry. An increase in the ultrasonic output power and abrasive concentration within a certain range lead to a more desirable polishing effect.

The initiation and propagation of cracks generated on a work surface during UltraSonic Machining (USM) were simulated using Smoothed Particle Hydrodynamics (SPH). Different abrasive materials, tool materials, and abrasive sizes were used in this simulation. The distribution and size of the calculated cracks were found to be strongly influenced by different process conditions. According to the simulation results, using tools with a lower yield strength and slurry comprising softer and smaller abrasives decreases the crack size. Experiments were conducted to drill deep blind holes in soda-lime glass by USM and observe the cracks remaining on the machined surfaces. The experimental results agreed well with the simulation results. This work was the first to visualize the crack formation during USM under different process parameters with the SPH method. The results may be very useful for improving the machining performance of the USM process.

Hammering action plays a primary role in material removal in ultrasonic machining (USM). In the present study, Smoothed Particle Hydrodynamics (SPH) is used to simulate the hammering action of a single silicon carbide abrasive particle on a float glass workpiece, and the implications for crack initiation and propagation on the workpiece are discussed in detail. The adequacy of the SPH model is verified through an experiment that utilizes a stationary ultrasonic drilling machine. It is shown that the distribution and size of the cracks on the sample workpiece are well in agreement with the simulation results. The current study presents a new way to understand the material removal process of USM, which is extremely significant for the further improvement of the performance of USM techniques.

An efficient diastereo- and enantioselective Michael addition of 3-substituted oxindoles onto nitroalkenes catalyzed by a bifunctional chiral squaramide catalyst has been developed. This organocatalytic reaction with 2 mol % of catalyst proceeded smoothly to afford 3,3-disubstituted oxindoles in high yields with good diastereoselectivities and enantioselectivities (up to 98:2 dr, 88% ee).

An efficient diastereo- and enantioselective Michael addition of 3-substituted oxindoles onto nitroalkenes catalyzed by a bifunctional chiral squaramide catalyst has been developed. This organocatalytic reaction with 2 mol % of catalyst proceeded smoothly to afford 3,3-disubstituted oxindoles in high yields with good diastereoselectivities and enantioselectivities (up to 98:2 dr, 88% ee).

To find out the status and distribution characteristics of senile cataract, which is one of the common disease affecting the quality of life of the elderly people.One thousand and sixteen people aged 60 or more in the urban and rural areas of Chengdu were included by cluster random sampling and investigated by questionnaire method and medical examination.It was found that the prevalence of senile cataract was 52.3% in urban area and 51.3% in rural area. The prevalence was higher in women than in men, and it increased with age. The prevalence of senile cataract by past diagnosis was lower than that by present medical examination; this difference was found obvious in the rural area.The prevention and treatment of senile cataract should be strengthened.