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Optical Music Recognition (OMR) is an important way to digitize score images and has broad application prospects in fields such as the storage of music documents, music education and digital creation. As a new paradigm for object detection, DETR (detection transformer) has the ability to associate contextual information, which can be exploited to resolve the OMR task. However, the original DETR does not fit OMR well due to its high computational complexity and numerous parameters. To address the DETR defects and improve the recognition accuracy of OMR, we propose a novel multi-scale DETR (M-DETR) with a multi-scale feature fusion mechanism and improved attention mechanisms. First, a new multi-scale feature fusion mechanism is designed to let the backbone network of M-DETR get rich multi-scale information. Then, a key-region attention mechanism is incorporated based on the character that the key information is concentrated on a score image. Finally, the pre-context attention mechanism is introduced to make better use of the contextual association between recognition notes in music scores. Experiment results show that M-DETR achieves recognition accuracy of 90.6% for 7 typical small-sized notes, which is better than Faster R-CNN and YOLO v5, and the improvement rate is 10.02% compared to the original DETR algorithm. The results indicate that M-DETR is an effective way for the OMR task, which also provides a new solution for the detection of small-sized objects with contextual association. • A backbone network with a feature fusion mechanism. • A key-region attention mechanism on the information of the head regions. • A pre-context attention mechanism with correlation among the targets in music scores. • A novel M-DETR algorithm to improve the recognition accuracy for OMR. [ABSTRACT FROM AUTHOR]

Harsh environments in poorly perfused tumor regions may select for traits driving cancer aggressiveness. Here, we investigated whether tumor acidosis interacts with driver mutations to exacerbate cancer hallmarks. We adapted mouse organoids from normal pancreatic duct (mN10) and early pancreatic cancer (mP4, KRAS-G12D mutation, ± p53 knockout) from extracellular pH 7.4 to 6.7, representing acidic niches. Viability was increased by acid adaptation, a pattern most apparent in wild-type (WT) p53 organoids, and exacerbated upon return to pH 7.4. This led to increased survival of acid-adapted organoids treated with gemcitabine and/or erlotinib, and, in WT p53 organoids, acid-induced attenuation of drug effects. New genetic variants became dominant during adaptation, yet they were unlikely to be its main drivers. Transcriptional changes induced by acid and drug adaptation differed overall, but acid adaptation increased the expression of gemcitabine resistance genes. Thus, adaptation to acidosis increases cancer cell viability after chemotherapy. [Display omitted] • Acid adaptation of pancreatic organoid increased viability and chemotherapy resistance • This response was enhanced upon return to physiological pH • Transcriptional changes induced by acid and drug adaptations are overall dissimilar • Acid adaptation led to more genotype changes compared to growth in physiological pH Stigliani et al. show that when pancreatic organoids from normal ducts and PanINs are adapted to an environment mimicking acidic tumor niches, they gain cancer hallmarks including increased viability and drug resistance. [ABSTRACT FROM AUTHOR]

• Dual bronchodilations therapy is the approach for treating patients with moderate to severe COPD, and can relieve dyspnea. • Dual bronchodilators may increase the incidence of MACE, so we maked a meta-analysis on the efficacy and safety of IND/GLY. • IND/GLY significantly reduced incidence of acute COPD exacerbations, and did not increase adverse cardiovascular events. Bronchodilators are the cornerstone for treating patients with chronic obstructive pulmonary diseases (COPD), although some studies have shown that dual bronchodilators may exacerbate incidence of adverse cardiovascular events. Here, we evaluated the cardiopulmonary safety of indacaterol/glycopyrronium (IND/GLY) using a meta-analysis. We searched PubMed, OVID, Cochrane Library and Web of Science databases, using "indacaterol/glycopyrronium", "indacaterol/glycopyrrolate", "IND/GLY", "QVA149", "chronic obstructive pulmonary diseases", "COPD", "chronic obstructive airway disease", "chronic obstructive lung disease" as key words. Acute exacerbation of COPD and FEV 1 as indicators of pulmonary function and occurrence of hypertension, atrial fibrillation, myocardial infarction and heart failure as indicators of cardiovascular safety. A total of 23 articles, comprising 21,238 participants, were included in the analysis. FEV 1 values were significantly different compared to IND/GLY and single bronchodilator therapy (LABA or LAMA), with the MD 0.11 L (95%CI: 0.10–0.13, P <0.01). Hypertension was more frequent in the IND/GLY, than the single bronchodilator therapy group, although this difference was insignificant (IND/GLY vs LABA, RR=1.88, P = 0.09; IND/GLY vs LAMA, RR=1.42, P = 0.08; IND/GLY vs LABA+ICS, RR=1.85, P = 0.23). In addition, IND/GLY did not significantly increase the risk of myocardial infarction (IND/GLY vs LAMA or double therapy, total RR: 1.49, 95%CI: 0.72–3.08, P = 0.28), atrial fibrillation (IND/GLY vs LAMA, RR: 1.62, 95%CI: 0.64–4.10, P = 0.31) and heart failure (IND/GLY vs LAMA, RR: 0.40, 95%CI: 0.07–2.33, P = 0.31) in COPD patients. IND/GLY significantly reduced incidence of acute COPD exacerbations, and slowed down the decline of FEV 1. Adequate safety measures are needed to control incidence of adverse cardiovascular events. [ABSTRACT FROM AUTHOR]

Polycrystalline Al workpieces go through a complex surface atom sputtering and surface/subsurface atom diffusion throughout the ion beam machining process that plays a critical role in determining machining quality of optical mirror surfaces. Here, we leverage molecular dynamics method for the first time to reveal the machining mechanism and the polycrystalline effect of aluminum during ion beam sputtering, in term of cascade collision, atom trajectory, sputtering yield, and surface characteristic. Polycrystalline Al presents a significant low potential energy state, leading to milder cascade collision and weaker sputtering effects than monocrystalline Al during ion beam machining. The atom trajectory demonstrates irregular variation as the atom diffusion is blocked by grain boundary (GB) in polycrystalline Al, leading to the relief microstructure and poor surface quality. With incident ions increasing, the GBs are broken and atom diffusion enhancing, as well as lower subsurface defects and better finishing surface quality. The microscopic morphology evolves into gravel microstructure. Simulation results also reveal that atom diffusion will benefit from high ion concentration and low ion energy. Sputtering yield variation is more sensitive to ion energy. To acquiring better finishing surface quality of Al without influencing machining efficiency, ion concentration must be increased while the ion energy needs to be decreased appropriately but a large number of cascading collisions need to be ensured. • The machining mechanism and polycrystalline effect of Al during ion beam sputtering are investigated via molecular dynamics simulation. • Cascade collision is milder in polycrystalline Al, and atom trajectory demonstrates irregular variation as the atom diffusion blocked by grain boundary. • Impeding effect of grain boundaries induces the relief microstructure. With incident ions increasing, the grain boundaries are broken, and the gravel structure dominates the surface morphology. • Lower ion energy and higher ion concentration will benefit atomic diffusion, inducing a better finishing surface roughness. [ABSTRACT FROM AUTHOR]

Carbon market is the most effective market tool for carbon emission reduction. China, the largest carbon emitter in the world, established the national carbon market in 2021, covering over 2000 key units in the power sector. Therefore, the forecasting of carbon price has profound implications for environmental and energy policies. In this paper, two traditional econometric model and three kinds of machine learning (ML) algorithms are used to predict carbon returns in the Chinese carbon trading market based on carefully selected predictors. Among all forecasting models, the Random Forest (RF) has the best forecasting performance, followed by some GARCH models using various factors. Compared with the traditional benchmark of ARMA model, the BP neural network (BP) and the GA improved BP method (GA-BP) are less competitive in predicting carbon returns in China because of their large forecasting errors. According to the optimal model, social attention to the carbon market, the international crude oil returns and the overall performance of the stock market are the most important predictors. The findings are robust to the change in the sample set. Overall, the ML approach shows an advantage in forecasting carbon returns, but the selection of predictors is also important. • Machine learning and econometric models are used to forecast carbon returns in China. • The selection of predictors is based on economic analysis. • The Random Forest (RF) outperforms the other ML and econometric methods. • The energy market is extremely important for predicting carbon returns. • Social concerns and stock market performance improve forecasting accuracy. [ABSTRACT FROM AUTHOR]

DNA has many unique properties beyond encoding genetic information, one of which is its physicochemical stability based on Watson–Crick base pairing. Differences in sequence complementarity between multiple DNA strands can lead to the strand displacement reaction (SDR). SDRs have been regularly applied in synthetic biology, drug delivery, and, importantly, biosensing. SDR-based biosensors have high controllability, high sensitivity, and low interference, and can be used for multiplexed detection. Such biosensors have been demonstrated to detect nearly every class of biomolecule. As the field continues to mature, such platforms can be used as an integral tool for the manipulation of biomolecular reactions, bringing biosensors one step closer to the ultimate goal of point-of-care systems. SDRs directly connect a biosensing recognition event to its signaling event, producing simple, integrated platforms. Combining SDRs into cascades provides inherent amplification of target signals, thus boosting the sensitivity of the biosensing system. The incorporation of orthogonal strand displacement cascades allows multiplexed detection of multiple targets in one sample. SDRs can be applied universally to a diverse type of targets, including nucleic acids, proteins, and small molecules. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Different tunnel structured MnO 2 nanoparticles were synthesized and characterized. • The first investigation on the effect of tunnel structured MnO 2 on electrochemical oxidation of nitrite. • α-MnO 2 found to be the most reactive structure for electrochemical sensing. Abstract Three MnO 2 nanoparticles with different tunnel structures, α-, β-, and γ-MnO 2 , were synthesized and characterized. We demonstrated and compared their capabilities on the electrochemical oxidation of nitrite, providing a new perspective for MnO 2 or MnO 2 based materials on sensing application. α-MnO 2 exhibited higher electrochemical reactivity than β- or γ-MnO 2 , which was ascribed to its higher conductivity, more exposure to MnO 6 edges, longer average Mn O bond length, and lower Mn average oxidation state(AOS). We hereby reported the first α-MnO 2 nanoparticle-based electrochemical sensor for nitrite sensing. A highly controlled micro-plotter was used to deposit the MnO 2 nanoparticles for the sensor fabrication, providing a micro-pattern of the sensing surface area of MnO 2 and ensuring the reproducibility and sensitivity of this MnO 2 based sensor. Using differential pulse voltammetry, a detection range of 10–800 μM of nitrite was accomplished along with a sensitivity of 17.1 μA μM−1 and a detection limit of 0.5 μM. [ABSTRACT FROM AUTHOR]

As the thickness of the adhesive layer between the mirror and the actuator decreases and the performance requirements of the unimorph deformable mirror (DM) increase, stricter control on the adhesive layer thickness and Young’s modulus is necessary. In this paper, a finite element model (FEM) for the unimorph DM with an adhesive layer is obtained. Based on the model, the influence of adhesive layer thickness and Young’s modulus on the deformation is studied. Also their influence on the adhesive’s maximum shear stress is analyzed. In the meantime, the design principles of the adhesive layer thickness and Young’s modulus are established with the restrictions of shear failure and the maximum displacement. As a result, different adhesive Young’s modulus has corresponding requirements for the upper and lower thicknesses (<20 μm) to obtain 85% maximum displacement. Then, DMs with four different mirror thicknesses are fabricated for verification experiments. The experiments results can be matched with the simulation results. Finally, the thickness in the spin coating process of adhesive layer is explored. The adhesive layer thickness can be controlled within 12.1 μm, and the deviation of uniformity is better than ±2%. [ABSTRACT FROM AUTHOR]

To restrain surface deliquescence which directly influences surface quality and machining efficiency of polishing KDP crystal, this paper presents a novel water-dissolution magneto-rheological finishing process by controlling fluid-crystal temperature difference. Deliquescence mechanism is revealed from the perspective of deliquescence circle. Micro-condensation is proved as the main cause of deliquescence, which is restrained by fluid-crystal synergistic heating. Case test on KDP crystal verified that the humidity threshold of anti-deliquescence rises from 40% to 80%, which has realized synchronous improvements of machining efficiency as well as surface roughness and laser induced threshold on KDP crystal during the process of water-dissolution magneto-rheological finishing. [ABSTRACT FROM AUTHOR]

Because of finite stiffness of grinding system, grinding force will cause the tool deflection (the difference between actual cutting depth and nominal cutting depth). During helix path contour grinding, the grinding condition are variable at different grinding point which will bring forward different tool deflection and result in dimensional errors. This paper presents an error analysis model during multi-pass grinding, which can predict the accumulation process of surface profile error induced by tool deflection. It establishes the relationship between profile error and grinding parameters. The estimation method of key model parameters is described in the proposed model through series of experiments. According to the error analysis model, we can implement the varied feed rate and varied cutting depth method for compensating the profile error. The grinding experimentation and compensation grinding verifies the validity of error analysis model and effectiveness of compensation method, and the profile error reduced by 82.1% comparing with grinding process without compensation. [ABSTRACT FROM AUTHOR]

Aiming to develop a prototype swing arm profilometer for several meter-class aspheres, we first present detailed error analysis including error motions of the swing rotary table and the part rotary table, and misalignment of the axes of the two rotary tables. The induced probing error in the normal direction of the reference sphere is calculated by considering the error motions in the coordinate transformation. A surface reconstruction algorithm is then proposed to separate the error motions of the part rotary table by stitching multiple traces. The error motions are optimally recognized and then removed from the trace measurement based on the least squares principle. We model the objective function by relating the normal error to the rigid body transformation of each trace. The basic idea is to minimize the inconsistency of all intersection points of different traces simultaneously. Finally the algorithm is verified through simulations. It shows that error motions of sub-milliradian scale are even tolerant with the surface reconstruction algorithm. [ABSTRACT FROM AUTHOR]

Abstract: Stitching test of large optical flats is still quite challenging. In this paper, aiming to reduce the 2nd order error accumulation effect, separation of the reference surface error from the subaperture measurements is proposed in stitching of large flats. The reference error is decomposed into power and astigmatism, residual Zernike polynomial surface and high frequency component, which are estimated or calibrated, respectively. The error separation procedure is then incorporated into the subaperture stitching algorithm. Finally experiments are presented to show the effect of error reductions in stitching test of a 600mm-aperture flat, with reference surface separated and verified by the factory report of the transmission flat. [Copyright &y& Elsevier]

Abstract: In an ion-beam figuring (IBF) process, the desired material removal, which is specified to the contour algorithm to calculate dwell time, decides the calculated process time and the resulted residual surface figure error. Usually, an IBF process with more removal consumes a longer process time, although the resulted residual error is smaller, whereas an IBF process with less removal needs only a shorter process time, but the resulted residual error is greater. Therefore, in order to balance the process time and the residual error, an optimum removal should be determined. In this study, the characteristic relationship between the process time and the residual error on different specified removals is investigated first. The investigation shows that for smaller removals, the residual error decreases rapidly while the process time increases slowly, and for larger removals, the process time increases rapidly without much decrease in residual error. This characteristic makes the figure-prediction curve (process times vs. rediual errors (RMS)) often in the shape of the letter “L”. Therefore, the optimum removal can be determined at the corner of the curve. Finaly, experiments are performed to verify the proposed method. [Copyright &y& Elsevier]

Curcumin is antioxidative, liver protective and it has lipid regulatory effects. However, its in vivo efficiency is limited because of the low absorption rate and bioavailability. LVYP (Leu-Val-Tyr-Pro) is a tetrapeptide isolated, purified and identified from Corbicula fluminea with strong antioxidant activity. The interaction mechanisms between curcumin and LVYP were investigated using UV–vis absorption and fluorescence spectra. The results showed that the interaction between curcumin and LVYP was hydrophobic. When the temperature was increased from 25 to 37 °C, ΔG decreased and the number of ligand molecules increased, the interaction was quenched statically explained the formation of some compounds. On the other hand, dynamic quenching occurred when the temperature reached 60 °C, ΔG increased and the number of ligand molecules decreased, which indicated that temperature affected the interaction between curcumin and LVYP. This study also showed that LVYP could promote intestinal absorption of curcumin, predominantly in the ileum, which was explored using a non-everted intestinal sac model. In vivo experiments showed that the liver's protective effect with the combined administration of LVYP and curcumin was better than the curcumin alone, and LVYP could promote the hepatoprotective function of curcumin. It was hypothesized that the interaction of LVYP and curcumin enhanced the intestinal absorption rate of curcumin, thereby increasing its liver protection effect. • Interaction between curcumin and LVYP was mediated by temperature. • LVYP could promote intestinal absorption of curcumin. • An animal model of alcoholic liver injury was established. • LVYP enhanced the liver protection effect of curcumin. [ABSTRACT FROM AUTHOR]

Subaperture stitching test in combination of the reconfigurable optical null we proposed recently provides flexible solutions to various surfaces including convex aspheres and even aspheres of large aperture. However it is challenging for the stitching optimization to get the real surface error because the surface error is strongly coupled with misalignment-induced aberrations in near-null subaperture measurements. Aiming at this challenge, we first figure out the property of aberrations induced by misalignment of optical null or test surface. It shows that identical misalignment of the optical null introduces nearly identical aberrations to subapertures with different off-axis distances, while misalignment of the test surface introduces little aberrations to the central subaperture. The stitching algorithm is then proposed with focus on decoupling surface error and induced aberrations. The major step is to calibrate out the effect of misaligned near-null optics before stitching optimization by using the central subaperture measurement. We also present the through-the-back null test for the purpose of cross test. The axial distance is precisely monitored by a low coherence interferometer, which enables accurate determination of the spherical aberration component of surface error. Final experimental results show consistent spherical aberration obtained by stitching test and by the through-the-back null test. It is a big step towards instrumentation of subaperture stitching test for aspheres with rather big amount of misalignments in surface metrology practice. [ABSTRACT FROM AUTHOR]

The roundness of the journal directly affects the radial synchronous error (RSE) of the aerostatic spindle. However, the state-of-the-art ultra-precision grinding machine can only achieve a roundness of 0.2–0.3 µm, which limits the improvement of the rotating accuracy. Hence, novel time-controlled grinding (TCG) is proposed to further converge the rotor's roundness. To provide the machining basis and prediction, CFD is used to quantitatively analyze the effect of roundness on the flow field and a rotating trajectory model is established. Based on the model's guidance, the rotor's average roundness converged to 0.08 µm by TCG, even better than manual lapping, and the RSE decreased from ∼30 nm to ∼11 nm synchronously, proving the model's and TCG's feasibility and potential. [Display omitted] • TCG breaks the limit of current ultra-precision grinding, further improving the precision of the rotor in aerostatic spindle. • Quantitative relationship between the bearing capacity of the air film and roundness error of the rotor is obtained by CFD. • A model based on the roundness error and unbalanced mass is established to explain and predict the radial synchronous error. • Radial synchronous error reduced from ∼ 30 nm to ∼ 11 nm after TCG and is expected to reach 8 nm after dynamic balance. [ABSTRACT FROM AUTHOR]

Abstract: Subaperture stitching interferometry combined with a test plate is attractive for testing large convex aspheres, but the stitching algorithm is challenging because the aberrations induced by misaligned test surface or test plate are coupled with the surface figure. By relating the subaperture configuration to the overlapping deviations through ray trace and coordinate transformation, the subaperture misalignment is optimally recognized and corrected to give a minimal overlapping inconsistency in an iterative way. Allowing for misaligned test plate, we decompose the induced aberrations into three parts which are corrected by the stitching algorithm, removed in the form of the Zernike polynomials and left uncorrected as residuals. Finally we present simulation results of testing a convex aspheric mirror with a computer generated hologram which shows the algorithm successfully retrieves the surface figure with the test mirror or the hologram misaligned. [Copyright &y& Elsevier]

Robust developments of personalized medicine for next-generation healthcare highlight the need for sensitive and accurate point-of-care platforms for quantification of disease biomarkers. Broad presentations of clustered regularly interspaced short palindromic repeats (CRISPR) as an accurate gene editing tool also indicate that the high-specificity and programmability of CRISPR system can be utilized for the development of biosensing systems. Herein, we present a CRISPR Cas system enhanced electrochemical DNA (E-DNA) sensor with unprecedented sensitivity and accuracy. The principle of the E-DNA sensor is the target induced conformational change of the surface signaling probe (containing an electrochemical tag), leading to the variation of the electron transfer rate of the electrochemical tag. With the introduction of CRISPR cleavage activity into the E-DNA sensor, a more apparent signal change between with and without the presence of the target can be achieved. We compared the performance of Cas9 and Cas12a enhanced E-DNA sensor and optimized the chemical environment of CRISPR, achieving a femto-molar detection limit without enzymatic amplification. Moreover, we correlated the CRISPR cleavage signal with the original E-DNA signal as a strategy to indicate potential mismatches in the target sequence. Comparing with classic DNA electrochemistry based mutation detection strategy, CRISPR enhanced E-DNA sensor can determine the presence of a single mutation at an unknown concentration condition. Overall, we believe that the CRISPR enhanced E-DNA sensing strategy will be of especially high utility for point-of-care systems owing to the programmability, modularity, high-sensitivity and high-accuracy. Image 1 • Surpassing the detection limit of conventional stem loop-probe based E-DNA sensing system. • Application of CRISPR Cas9/Cas12a systems for electrochemical sensing. • Complementarity dependent CRISPR enzymatic activity for mutation analysis. • Dose-independent discriminating single-mutation through CRISPR enhanced DNA electrochemistry. [ABSTRACT FROM AUTHOR]

Cachexia, a metabolic syndrome, affects 21 % of patients suffering from ischemic encephalopathy. However, the specific mechanism and prevention measures are still unclear. Omega-3 polyunsaturated fatty acids (n−3 PUFAs) have been proven to reduce inflammatory cytokine levels during ischemic events, but whether they have a protective effect against cachexia after hypoxic-ischemic brain damage (HIBD) remains unclear. C57BL/6J wild-type and mfat-1 transgenic male mice were treated with and without HIBD. One day after HIBD, the epididymal white fat, gastrocnemius muscle and hypothalamus were weighed and analyzed the phenotypic changes. RNA sequencing was applied to gastrocnemius muscle to identify differential genes and pathways in HIBD groups. The effect of HPA axis on cachexia post-HIBD was examined via adrenalectomy, dexamethasone (0.1 mg/kg), and corticosterone injection (100 mg/kg). The results showed that the incidence of cachexia in mfat-1 mice, which produce high proportion of n−3 PUFAs, was significantly lower than that in wild-type mice post-HIBD. Cachexia-related factors, such as inflammation, muscle atrophy and lipid metabolism were significantly improved in mfat-1 HIBD. RNA sequencing revealed that catabolic and proteasome pathways were significantly downregulated. In hypothalamus, inflammatory cytokines, lipid peroxidation levels were reduced. Corticosterone, glucocorticoid receptor, and dexamethasone suppression test all showed that mfat-1 improved the dysfunction of the HPA axis post-HIBD. The present study elucidated for the first time that mfat-1 reduced HIBD-induced hyperactivation of the HPA axis in mice by reducing inflammation and oxidative stress and contributed to the reduction of metabolic imbalance in peripheral tissues. Our study provides mechanistic information for the development of intervention strategies to prevent cachexia. [ABSTRACT FROM AUTHOR]

Phenylethanoid glycosides derived from Cistanche deserticola (PhGs) are plant-derived natural medicinal compounds that occur in many medicinal plants. This study aims to investigate whether PhGs treatment improves the stroke and its potential mechanisms. Adult male C57BL/6 J mice were administrated PhGs once daily for 7 days after MCAO surgery. The neurological score, and catwalk were evaluated on Day 1, 3 and 7 after ischemic stroke. Furthermore, triphenyl-2,3,5-tetrazoliumchloride (TTC) and hematoxylin-eosin (H&E) staining were used for evaluating the infarct volume and neuronal restoration. The effects of PhGs on NSCs proliferation were investigated in vitro and in vivo. Western blot was used to detect the proteins of Wnt/β-catenin signaling pathway. This study found that PhGs effectively improved the neurological functions in ischemic stroke mice. TTC and H&E staining demonstrated that PhGs not only reduced infarct volume, but also improved neuronal restoration. The immunohistochemistry and 5-Ethynyl-2-deoxyuridine (EdU) incorporation assays revealed that PhGs promoted the proliferation of neural stem cells (NSCs) in subventricular zone (SVZ). In addition, transcriptome analysis of NSCs showed that the Wnt/β-catenin signaling pathway was involved in the PhGs induced NSCs proliferation. Importantly, the related proteins in the Wnt/β-catenin signaling pathway were changed after PhGs treatment, including β-catenin, Wnt3a, GSK-3β, c-Myc. PhGs treatment improved the stroke through enhancing endogenous NSCs proliferation via activating Wnt/β-catenin signaling pathway. Due to its effect on the proliferation of NSCs, PhGs are a potential adjuvant therapeutic drug for post-stroke treatment. [Display omitted] • PhGs improve outcomes in ischemic stroke. • PhGs promote the proliferation of NSCs contributing to the improvement of ischemic stroke. • PhGs improve stroke through enhancing endogenous NSCs proliferation via activating of the Wnt/β-catenin signaling pathway. [ABSTRACT FROM AUTHOR]

• Monolithic multiple surfaces simplifies the alignment by "freezing" surfaces. • Multiple surfaces including form and orientation are measured simultaneously by a single CGH. • Null test is used as feedback after mapping distortion correction. • Higher accuracy is achieved by corrective machining with fast axis servo. • Null fringes are experimentally observed for monolithic two mirrors in final test. Monolithic multiple freeform mirrors integrate two or more surfaces on a single substrate. Alignment of these surfaces is no longer required because they are frozen there as they are machined. Null test is then critical as a feedback to corrective machining which is indispensable for high accuracy optics. This paper presents a methodology for corrective machining of monolithic multiple freeform mirrors based on holographic null test capable of measuring multiple surfaces simultaneously. The surfaces are firstly related and modeled by coordinate transformation. A single computer generated hologram is then proposed with different regions to compensate aberrations of different surfaces. A combined tilt and power carrier is designed to separate the disturbance orders of diffraction. Mapping distortion in the null test is corrected through a pure ray tracing procedure by introducing a virtual reference sphere. The surface error including the orientation error is then superposed on the nominal surface to generate the tool path for corrective machining with fast axis servo. The tool radius and decenter is recognized by pre-cutting a spherical surface. The remounted workpiece is aligned with the machine tool by using an on-machine probe. Finally the proposed method is experimentally verified by corrective machining monolithic two mirrors with surface error effectively reduced and null fringes observed for both surfaces. [ABSTRACT FROM AUTHOR]

The volume fracturing in the Mahu conglomerate reservoir, double-wing fractures are generated, resulting in inadequate proppant laying effect and low fracture conductivity. Experiments are designed to explore methods for improving the conductivity of conglomerate-supported fractures. Real triaxial indoor experiments are conducted to explore the effects of displacement, stress difference, and weak surfaces. The proppant diversion experiment explores the diversion ability under the conditions of single proppant, mixed proppant, and multiple sand-laying concentrations. Attention is focused on the impact of proppant embedding and fragmentation on conductivity. Research has shown that (1) stepped variable displacement fracturing is beneficial for controlling the generation of fractures. High displacement is beneficial for activating naturally weak surfaces. Small displacements are beneficial for identifying naturally weak surfaces and controlling the speed of crack extension. (2) Embedding of proppants mainly affects the conductivity of mixed base-supported conglomerates. Crushing mainly affects the conductivity of particles supporting conglomerate fractures. (3) Quartz sand or quartz sand-mixed ceramsite is used for conglomerate reservoirs with low effective closure stress and a complex matrix. Ceramic particles can are reduce the impact of fragmentation on the conductivity of particle-supported conglomerate reservoirs. Study aims to provide scientific guidance for the efficient development of the Mahu reservoir. • Experiments are employed to optimize the conglomerate reservoir fracturing. • Variable displacement fracturing is beneficial to activate the natural fractures. • A method for high conductivity support-type fracture was developed. • The basis for selecting proppant for the Mahu reservoir was formed. [ABSTRACT FROM AUTHOR]

Recent studies in mice showed that the Ten-eleven translocation Enzymes (TET) family is involved in the active DNA demethylation. The isotype TET-3 is responsible for the conversion of 5mc (5-methylcytosine) to 5hmc (5-hydroxymethylcytosine) at the pronuclear stages of mouse embryo. This study was performed to investigate the pattern of methylation change and the role of TET family in the demethylation process of porcine in-vitro fertilization (IVF) and somatic cell nuclear transfer (SCNT) derived embryo. Bisulfite-sequencing PCR (BSP) and DNA glucosylation and digestion before quantitative PCR (qGluMS-PCR) were done to evaluate the exact change of methylation during porcine pronuclear stages. The results showed that the amount of 5hmc detected increased whereas 5mc decreased in IVF embryo from pronuclear stage 2 (PN2) to pronuclear stage 5 (PN5). In addition, Immunofluorescent staining showed that the 5hmc signal, also detected in oocytes, significantly increased in both pronucleus from fertilization to PN2. The amount of 5hmc continued to rise in male pronucleus but decreased to a very low level in female pronucleus from PN2 to PN5. The above results indicate that female pronucleus might undergo active demethylation only at early pronuclear stages. On the other hand, male pronucleus might undergo active demethylation throughout all pronuclear stages. The expression of three TET isotypes (TET-1, TET-2, TET-3) were tested and TET-3 was found to be the highest expressed isotype. High TET-3 concentrations observed mainly in male pronucleus using immunofluorescent staining, implying that TET-3 might be the main enzyme which catalyzes the conversion of 5mc to 5hmc. In contrast, no TET-3 signal was detected in female pronucleus through the pronuclear stages. The demethylation pattern of SCNT embryos resembled that of the male pronucleus of IVF embryos, suggesting that active demethylation might happen in porcine cloned embryo. [ABSTRACT FROM AUTHOR]

In order to improve tribological properties of tappets made of GCr15 bearing steel, a combination of martensitic heat treatment and surface texture was applied to the GCr15 bearing steel. The texture was designed based on a fluid-solid coupling simulation performed using COMSOl, and effectiveness of the designed texture was verified by performed wear tests using a pin-disk line contact rotary motion tester under oil lubrication condition. The worn surface morphology and wear mechanism for the friction pair were analyzed with three-dimensional scanning microscopy and scanning electron microscopy to reveal the antifriction behavior and wear resistance. Results of the study show that the heat treatment increased the surface hardness and significantly reduced wear of the GCr15 bearing steel. The designed surface texture helped reduce the contact area, store tiny wear debris, and increase the oil film pressure, thus improving the tribological performance. However, the texture edge was prone to severe plastic deformation due to the stress concentration and lowered lattice confinement. The martensitic heat treatment involving tempering effectively reduced plastic flow at the edge of texture. The combination of texture and the martensitic heat treatment considerably improved the tribological properties of GCr15 steel. [Display omitted] • Discuss the wear mechanism by synergistic modification of chemical heat treatment and surface texture. • Tribological test by simulating the actual cam tappet line contact method. • A fluid-solid coupling model is developed to analyze the effect of surface texture on friction characteristics. • The fluid domain is modeled with a new circular arc-shaped geometry that more closely matches the actual line contact. [ABSTRACT FROM AUTHOR]

Smooth polishing has a good improvement on the medium and high frequency errors of the workpiece, but the surface accuracy of the workpiece will be damaged subsequently. Therefore, a nonlinear compensation method is proposed. The realization mechanism, mathematical model and compensation effect of nonlinear compensated smooth polishing are illustrated separately and verified by experiments. In addition, the process parameters and motion trajectory are optimized by theoretical simulation. The experimental results demonstrate that the full-band error of the workpiece can be improved simultaneously by the smooth polishing method based on nonlinear compensation. The number of iterations for the figuring experiments and smooth polishing is greatly reduced by the nonlinear compensation model, which is significantly beneficial to improve the surface convergence speed and lower the manufacturing cost. • Mathematical model of nonlinear compensation is developed. • The full-band error of the workpiece is converged. • Toolpath is optimized. • Process parameters are optimized. [ABSTRACT FROM AUTHOR]

Abstract: A new seed layer TiW is proposed for SmCo5 films with perpendicular magnetic anisotropy. The influence of a TiW seed layer on the microstructure and the surface morphology of Cu underlayer are studied. The grain size and surface roughness dependence of Cu underlayer on the thickness and the annealing of the TiW seed layer are also investigated. The improvement in the perpendicular magnetic properties of SmCo5 film from the TiW seed layer is approved. The results show that a 5nm Ti3W7 seed layer improves the microstructure and surface morphology of Cu underlayer, and significantly improves the perpendicular magnetic properties of SmCo5 film. The diffusion barrier and a high melting point of the TiW seed layer are regarded as the physical mechanism of the improvement for SmCo5 film with perpendicular magnetic anisotropy. [Copyright &y& Elsevier]

Various items of roll molds are popularly used to fabricate different kinds of optical films for optoelectronic information and other new and high-tech fields, while the fabrication and evaluation of optical microstructures on the cylindrical roller surface is more difficult than ecumenic manufactured products. This paper investigates the machinability of microstructures on the roll based on a fast tool servo (FTS) system. First, the flexible hinge holder for FTS is designed and its structure parameters are optimized with finite element analysis and fatigue reliability theory. Then the tool radius compensation algorithm for complicated microstructures is deduced based on the surface fitting and bilinear interpolation algorithm of discrete data. Meanwhile, the evaluation index and method are proposed by the medium section method. Finally, a machining test of aspheric arrays on aluminum cylindrical surface is carried out, and the high quality of the microstructure indicates that the proposed method is able to fabricate optical microstructures. [ABSTRACT FROM AUTHOR]

Acid fracturing is a useful technique to stimulate carbonate reservoirs. Nowadays, acid leak-off becomes a vital problem during the operation of acid fracturing. In order to encounter this issue, alternating acid fracturing has been developed. However, the fracture propagation and the interaction between hydraulic fractures and natural fractures/caves during alternating acid fracturing are ambiguous. Hence, a series of alternating acid fracturing experiments covering coupling mechanics and chemical interaction were conducted for the first time. In this study, slick water, self-generating acid, cross-linked gel, and gelled acid were used as a fracturing fluid whereas the specimens for this experiment are carbonate outcrop which excavated from Dengsi Formation. The results show that: (1) acid fracturing can reduce fracturing pressure effectively as the acid will etch and weaken the natural fractures to let them easily connecting each other; (2) different pad fluid properties will have different impacts on the acid fracturing performance; (3) the interaction of hydraulic fractures and natural filled caves can be divided into five categories, and two of them had been observed in the experiments. Moreover, a new curvature-calculation algorithm has been developed based on the 3-D scanning technology. The results have a great significance for acid fracturing design and physical simulation experiments. In this work, we designed a new method to simulate alternate acid fracturing process based on true tri-axial experiment system. And the study had investigated the effects of pad fluid on acid fracturing treatment. • We designed and executed the alternating acid fracturing physical simulation based on tri-axial experiment for the first time; • The interaction between acid fractures and natural caverns had been observed and classified; • New method of depicting surface of acid fractures based on 3-D scanning method had been invented. [ABSTRACT FROM AUTHOR]