•Olivine and serpentine behave differently with respect to mechanical activation.•Mechanical pre-treatment is effective to activate olivine containing materials.•Combining chemical and mechanical ...activation is favorable to activate serpentine.•An integrated mineral carbonation process may put mechanical activation into practice.
Mechanical activation is one of the most efficient pretreatment methods used to accelerate the reaction rate in the mineral carbonation technology. This paper reviews the current research related to this technique with a specific focus on three types of magnesium silicates - olivine and serpentine, and partially serpentinized olivine. First, the effects of mechanical activation on magnesium silicates are listed and compared with regard to a variety of milling conditions, including diverse energy inputs, grinding aids and mill types. Then, the existing literature determines the extents of mechanical activation, reviewed with respect to downstream carbonation processes, including direct gas/solid carbonation, direct aqueous carbonation, indirect aqueous carbonation, and indirect solid/solid mechanochemical carbonation. Finally, suggestions are made for further study on applying mechanical activation in an integrated mineral carbonation process, in order to lower the energy consumption of commercial systems.
•A novel geometrical nonlinear model for piezoelectric energy harvesters is proposed.•The high order terms of the derivative of deflection are consistently handled.•The effects of geometrical ...nonlinearity on the boundary conditions are considered.•The proposed model shows better agreement with experiments on the output voltage in comparison with the common geometrical nonlinear model..
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Current theories inconsistently handled the geometrical nonlinearity of cantilevered piezoelectric energy harvesters (PEHs) in two aspects: first, some of the high order terms of the first derivative of deflection were unintentionally omitted in deriving the governing equations; second, the effect of the geometrical nonlinearity on the motion of the tip mass was neglected. In this paper, a consistent geometrically nonlinear model (CGNM) was derived by neglecting the fourth and higher order terms of the first derivative of deflection in the governing equations, and by considering the effect of geometrical nonlinearity on the motion of the tip mass. For a flexible unimorph cantilever, the errors caused by either of the inconsistent treatments of the geometrical nonlinearity were numerically analyzed, respectively, and the theoretical and experimental results showed that both of them have remarkable effects on the simulation accuracy under harmonic base excitations with the amplitudes of 1.5 g and 2.0 g (g = 9.81 m s−2). Under excitations of different levels, the voltage across a 500 kΩ resistor worked out from a published geometrically nonlinear model (GNM) and the proposed CGNM were compared with experiments. The CGNM is more accurate than the GNM in the prediction of the root mean square (RMS) voltage at the resonant frequency, especially under high-level excitations. Numerical simulations show that the optimum load resistance increases and the resonant frequency decreases when the excitation level increases due to the geometrical nonlinearity. The model may be used to predict the responses of cantilevered PEHs experiencing large amplitude vibrations.
Abstract Background To develop and evaluate a predictive nomogram for polyuria during general anesthesia in thoracic surgery. Methods A retrospective study was designed and performed. The whole ...dataset was used to develop the predictive nomogram and used a stepwise algorithm to screen variables. The stepwise algorithm was based on Akaike’s information criterion (AIC). Multivariable logistic regression analysis was used to develop the nomogram. The receiver operating characteristic (ROC) curve was used to evaluate the model’s discrimination ability. The Hosmer–Lemeshow (HL) test was performed to check if the model was well calibrated. Decision curve analysis (DCA) was performed to measure the nomogram’s clinical usefulness and net benefits. P < 0.05 was considered to indicate statistical significance. Results The sample included 529 subjects who had undergone thoracic surgery. Fentanyl use, gender, the difference between mean arterial pressure at admission and before the operation, operation type, total amount of fluids and blood products transfused, blood loss, vasopressor, and cisatracurium use were identified as predictors and incorporated into the nomogram. The nomogram showed good discrimination ability on the receiver operating characteristic curve (0.6937) and is well calibrated using the Hosmer–Lemeshow test. Decision curve analysis demonstrated that the nomogram was clinically useful. Conclusions Individualized and precise prediction of intraoperative polyuria allows for better anesthesia management and early prevention optimization.
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Pulsar research has been a hot topic in the area of astronomy since they were first discovered. Pulsar discovery is fundamental for pulsar research. While pulsars are now visible across the ...electromagnetic spectrum, pulsar searches with modern radio telescopes are most promising. As the performance of astronomical instruments improves, the number of pulsar candidates detected by modern radio telescopes grows at an exponential rate. The application of artificial intelligence to the field of pulsar-candidate identification can automatically and efficiently address the identification problem with enormous amounts of data. However, there are still significant challenges in enhancing the accuracy of deep-learning-based pulsar-candidate identification. These problems result primarily from the fact that real pulsar data is scarce: the number of candidates that can be successfully identified as real pulsars (positive samples) is much smaller than those candidates that turn out to not be pulsars but instead radio-frequency interference or noise (negative samples). This makes it difficult to train a machine-learning model that can accurately select those candidates that are real pulsars. Therefore a novel pulsar-candidate identification framework is proposed that combines a deep convolutional generative adversarial neural network (DCGAN) and a deep aggregation residual network (ResNeXt). To overcome sample imbalance, the DCGAN is utilized to generate images that approximate real pulsars, while observed and generated candidates are employed together to train the pulsar-candidate identification model ResNeXt. Experiments on the HTRU Medlat data set back up the framework’s performance. The precision, recall, and F1-score of the framework are 100%.
Choroidal neovascularization (CNV) is a common pathological feature of various eye diseases and an important cause of visual impairment in middle-aged and elderly patients. In previous studies, ...tetrahedral framework nucleic acids (tFNAs) showed good carrier performance. In this experiment, we developed microRNA-155-equipped tFNAs (T-155) and explored its biological effects on CNV. Based on the results of in-vitro experiments, T-155 could regulate macrophages into the antiangiogenic M1 type. Then, we injected T-155 into the vitreous of laser-induced CNV model mice and found that T-155 significantly reduced the size and area of CNV, inhibited blood vessel leakage. In summary, we prove that T-155 could regulate the inflammatory process of CNV by polarizing macrophages, thereby improving the symptoms of CNV. Thus, T-155 might become a new DNA-based drug with great potential for treating CNV.
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•T-155 could regulate the inflammatory process of CNV by polarizing macrophages, thereby improving the symptoms of CNV.•Thus, T-155 might become a new DNA-based drug with great potential for treating CNV.
Nonwoven fiber mats of chitosan with potential applications in air and water filtration were successfully made by electrospinning of chitosan and poly(ethyleneoxide) (PEO) blend solutions. ...Electrospinning of pure chitosan was hindered by its limited solubility in aqueous acids and high degree of inter- and intrachain hydrogen bonding. Nanometer-sized fibers with fiber diameter as low as 80 +/- 35 nm without bead defects were made by electrospinning high molecular weight chitosan/PEO (95:5) blends. Fiber formation was characterized by fiber shape and size and was found to be strongly governed by the polymer molecular weight, blend ratios, polymer concentration, choice of solvent, and degree of deacetylation of chitosan. Weight fractions of polymers in the electrospun nonwoven fibers mats were determined by thermal gravimetric analysis and were similar to ratio of polymers in the blend solution. Surface properties of fiber mats were determined by measuring the binding efficiency of toxic heavy metal ions like chromium, and they were found to be related with fiber composition and structure.
Glaucoma is the world's leading irreversible cause of blindness. It is characterized by progressive retinal ganglion cells (RGCs) loss and axon damage, and there is no effective prevention or ...treatment so far. In this study, tetrahedral frame nucleic acids (tFNAs) with various biological functions are selected as the carrier, and microRNA‐22‐3p (miR‐22) are modified by attaching them onto tFNAs to synthesize a novel DNA nanocomplex (tFNAs‐miR22). Relevant results show that tFNAs can efficiently transfer miR‐22 into damaged retinal neurons to impose a neuroprotective effect on glaucoma. More interestingly, a certain synergism between tFNAs and miR‐22 is shown. tFNAs‐miR22 can selectively activate tyrosine kinase receptor B (TrkB) and regulate the TrkB‐brain‐derived growth factor (BDNF) signaling pathway to restore the expression of BDNF on the models of N‐methyl‐D‐aspartate (NMDA)‐induced glaucoma in vivo and in vitro, thus exerting the neuroprotective effect on retinal neurons. This study shows the successfully establishment of a simple but effective delivery system of microRNAs associated with glaucoma treatment, which may be a promising neuroprotective agent for future treatment of this optic neurodegenerative disease.
MicroRNA‐22‐3p (miR‐22) is modified by attaching it onto tetrahedral framework nucleic acids (tFNAs) to synthesize a novel DNA nanocomplex (tFNAs‐miR22). A simple and effective delivery system is established that can safely and quickly transfer miR‐22 into retinal neurons. tFNAs‐miR22 can reverse NMDA‐induced apoptosis of retinal neurons by regulating the TrkB‐BDNF signal pathway, thus achieving a neuroprotective effect for damaged retinal neurons.
The effect of DyMg co-deposition and diffusion on magnetic properties and service stability of sintered Nd-Fe-B magnets was investigated in this paper. The coercivity increased from 13.26 kOe for ...original magnet to 18.21 kOe after DyMg diffusion. As compared to single Dy diffusion, the Dy consumption was reduced by 39% in DyMg-diffused magnets. The thermal stability and corrosion resistance of the DyMg-diffused magnet improved significantly. The microstructure and element distribution were observed by SEM, EPMA and TEM. Mg element or Dy–Mg alloy repaired the damaged grain boundary to form a low melting point diffusion channel in the magnet and improved the distribution uniformity of the Dy-rich shell. In addition to the increase of magnetocrystalline anisotropy of the main phase, the optimization of the grain boundary phase is found to be a key factor for the effective improvement of coercivity.
•Dy and Mg are separately deposited on the Nd-Fe-B magnets.•The coercivity of the DyMg-diffused magnet increased from 13.26 to 18.21 kOe.•Both the thermal stability and corrosion resistance are improved by the diffusion of DyMg.•The formation of Dy–Mg alloy is beneficial to promote the distribution of the Dy-rich shell.•The diffusion mechanism of HRE with low melting point element is proposed.
Bisphosphonates are often used to treat osteoporosis, malignant bone metastases, and hypercalcemia. However, it can cause serious adverse reactions, bisphosphonate-related osteonecrosis of the jaw ...(BRONJ), which seriously affects the quality of life of patients. At present, the treatment of BRONJ is still difficult to reach an agreement, and there is no effective treatment. Therefore, it is very important to find effective treatments. Many studies have shown that the occurrence of BRONJ may be due to unbalanced bone turnover, anti-angiogenesis, bacterial infection, direct tissue toxicity, and abnormal immune function. The previous research results show that tetrahedral framework nucleic acids (tFNAs), a new type of nanomaterial, can promote various biological activities of cells, such as cell proliferation, migration, anti-inflammation and anti-oxidation, and angiogenesis. Therefore, we intend to explore the potential of tFNAs in the treatment of BRONJ through this study. The results show that tFNAs can promote the treatment of BRONJ by promoting angiogenesis and promoting M2 polarization in macrophages and inhibiting M1 polarization both in vitro and in vivo. These results provide a theoretical basis for the application of tFNAs in the treatment of BRONJ and also provide new ideas and methods for the treatment of other diseases based on ischemia and immune disorders.
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