Search

Theoretical analysis, numerical simulations, and experimental studies are used to comprehensively investigate the changes in the heat transfer characteristics of Fe3O4–water magnetic nanofluid under different types of magnetic fields and the heat transfer mechanism, providing new ideas for its practical application. By combining the fundamental conservation theorem and the Boussinesq approximation, dimensionless control equations have been established. The analysis of the variation pattern of the calculated values of the source terms under different boundary conditions, as well as the order of magnitude analysis, concludes that: the enhanced trend of Brownian motion and thermophoretic motion is the main reason for the enhanced heat transfer capability of the magnetic nanofluid; where the thermophoretic motion contributes slightly more to the heat transfer; the increase in Joule heat is the reason for the further enhancement of the heat transfer capability by the magnetic field. Volume fraction, temperature, and magnetic field strength are positively correlated with the average convective heat transfer coefficient. The reason for magnetic fields to enhance heat transfer is revealed by the deflection of the magnetic nanofluid by the magnetic body flow under local magnetic fields to form localized reflux. The alternating magnetic field further enhances the ability of magnetic fields to enhance heat transfer in magnetic nanofluids. Overall, the effect of the applied magnetic field on the motion of the magnetic nanoparticles causes the disruption of the thermal boundary layer, which is responsible for the enhanced heat transfer capacity of magnetic nanofluids. [ABSTRACT FROM AUTHOR]

AbstractThis study focuses on investigating the flow and heat transfer characteristics of Copper-water nanofluids (Cu-H2O) and water in microchannels with varying curvatures. The results reveal that Cu-H2O nanofluids demonstrate superior heat transfer performance compared to pure water in all four microchannels. Moreover, curved microchannels exhibit higher heat transfer performance than straight microchannels, regardless of whether the flow is laminar or turbulent. The heat transfer performance improves with increasing channel curvature, volume fraction of nanoparticles, and decreasing particle size. During laminar flow, the impact of curvature on heat transfer performance is more significant. However, during turbulent flow, variations in volume fraction have a greater influence on heat transfer performance compared to changes in curvature and particle size reduction. While larger volume fractions and higher curvatures increase flow resistance, this relationship is less pronounced for turbulent flow as Reynolds number and volume fraction increase. It is worth noting that the comprehensive heat transfer performance index does not consistently improve with increasing curvature, and sometimes straight microchannels outperform curved microchannels with specific curvatures. Additionally, curved microchannels exhibit a smaller average field synergy angle (FSA) compared to straight microchannels, indicating better synergy between the flow field and temperature field. The FSA also shows a relatively uniform distribution of local field synergy angles throughout the flow region in curved microchannels. Furthermore, the FSA decreases as the curvature increases. [ABSTRACT FROM AUTHOR]

This article numerically investigates the behavior of nonuniform distributed serrated fins including equaled, shortened, lengthened, short on both sides, and long on both sides. In outputs, not only the temperature field and velocity contour but also the synergy field were examined. The results show significant advantages of nonuniform fins, having certain characteristics, in improving the overall heat transfer performance. At the near entrance of nonuniform fin type, heat transfer can be improved by increasing fin length gradually, while it becomes worsened by decreasing fin length. The length of the first fin in the near inlet region has a great influence on the distribution of the temperature field. For the best array compared with the uniform case, the Colburn j factor increased by 9.1 − 16.8%. Either uniform or nonuniform fin type deteriorates the flow resistance while heat transfer capability is enhanced. From the perspective of synergy between temperature gradient and velocity, the local field synergy angle at the near inlet region, and the windward side of the fin has a decisive effect on the heat transfer performance. [ABSTRACT FROM AUTHOR]

For the serrated heat transfer surface, the heat transfer and flow properties are investigated with external vibration excitation using numerical simulation method. By using the dynamic grid to realize the vibration of the fin wall, the impacts of frequency, amplitude, wind velocity and ambient temperature on vibration-strengthened heat transfer are investigated. The results show that vibration impacts the temperature distribution around the fin, interferes with the flow of air, causes the air to form a certain angle with the fin wall, thus preventing the development of the boundary layer and achieving strengthened heat transfer. The impact of amplitude on vibration-strengthened heat transfer is smaller than that of frequency, and low wind velocity is more favorable to the role of vibration-strengthened heat transfer, and the change of ambient temperature has less impact. Compared with the stationary condition, wall vibration can improve the average heat transfer coefficient by up to 66.6%. [ABSTRACT FROM AUTHOR]

Neural electrodes are core devices for research in neuroscience, neurological diseases, and neural–machine interfacing. They build a bridge between the cerebral nervous system and electronic devices. Most of the neural electrodes in use are based on rigid materials that differ significantly from biological neural tissue in flexibility and tensile properties. In this study, a liquid-metal (LM) -based 20-channel neural electrode array with a platinum metal (Pt) encapsulation material was developed by microfabrication technology. The in vitro experiments demonstrated that the electrode has stable electrical properties and excellent mechanical properties such as flexibility and bending, which allows the electrode to form conformal contact with the skull. The in vivo experiments also recorded electroencephalographic signals using the LM-based electrode from a rat under low-flow or deep anesthesia, including the auditory-evoked potentials triggered by sound stimulation. The auditory-activated cortical area was analyzed using source localization technique. These results indicate that this 20-channel LM-based neural electrode array satisfies the demands of brain signal acquisition and provides high-quality-electroencephalogram (EEG) signals that support source localization analysis. [ABSTRACT FROM AUTHOR]

Nanofluids are important heat transfer mediums with great potential in industry applications because of its high thermal conductivity when adding metal or metalloid nanoparticles, which has better heat transfer characteristics and controllability than the base liquid. However, there are great uncertainties, deviations and anomalies in the computational model, experimental results and theoretical analysis when conducting research on the thermal physical properties, convective heat transfer performance and heat transfer mechanism of nanofluids. This poses a great challenge to the precise and active controllability of nanofluids when considering their own parameters and external excitation. Also, these inevitable problems may cause certain confusions on the follow-up study of nanofluids. Based on these phenomena, this paper systematically reviews the recent researches on heat transfer performance of nanofluids. The thermophysical characteristics, convective heat transfer coefficient, stability and heat transfer mechanism of suspension mixed nanofluids were summarized and compared. It is hoped that it can provide effective references and guidance for researchers to study the heat transfer performance of nanofluids, and also provide new ideas for future researches on the heat transfer performance of nanofluids. [ABSTRACT FROM AUTHOR]

Although there are many studies on the Jurassic source rocks in the northern margin of the Qaidam Basin, the characteristics of biomarkers and products with the same source rock in different evolutionary stages are still not well understood. Such an understanding is essential for accurately estimating oil and gas resources. In order to explore the hydrocarbon-generation potential of high-quality source rocks of the Middle Jurassic and the evolution of liquid hydrocarbons and biomarkers, we carried out simulation research (under hydrous conditions) at various temperatures (250, 300, 350, 400 and 450 °C) with the mudstone of the Yu 33 well in the Yuka Sag. The results revealed that the "oil window" of the Middle Jurassic source rocks in the Yuka area was 300 °C (simulation temperature, Ro = 0.84%), but this was not the peak of hydrocarbon expulsion, which was gradually reached and stabilized above 350 °C. Overall, the concentration of alkanes and aromatics increased with temperature; although the concentration of alkanes was complex in the low evolutionary stages, temperature (simulated maturity) was still the main factor controlling the change in alkanes and aromatics. Among the maturity parameters of biomarkers, the ratio of ∑tricyclic terpanes/∑hopanes was the most effective parameter for indicating the maturity evolution of the Yuka area, but others were complicated by the increasing temperature. Therefore, when evaluating maturity, the applicability of other parameters needed to be fully considered. The results obtained offer new insights in the research on liquid-hydrocarbon and biomarker evolution of the Middle Jurassic source rocks in the Yuka Sag of the Qaidam Basin. [ABSTRACT FROM AUTHOR]

The distribution of glycerol dialkyl glycerol tetraethers (GDGTs) in carbonate-type and sulfate-type saline lacustrine sediments from the Ordos Plateau in China is investigated to explore the influence of ionic composition on GDGTs. In general, they are relatively small (1.2–6.0 km2 surface area) and shallow ponds (0.05–0.2 m water depth) and even seasonally dry lakes. The results reveal that the concentration of GDGTs has a good positive correlation with the (nCO32− + nHCO3−)/total ions, and the concentration of GDGTs in carbonate-type lake sediments is significantly higher than that in sulfate-type lake sediments. Most GDGT-based indices show no significant differences, and the distributions of GDGTs are similar in the two types of saline lake sediments. The lack of a positive correlation between the content of clay minerals and the concentration of GDGTs may imply that the ability of clay minerals to carry terrigenous organic matter is very limited in arid climates. The branched GDGTS (brGDGTs) in the two saline lake sediments may mainly come from in situ biological production and have low terrestrial inputs. The different weathering level of feldspar minerals in the two types of saline lakes results in the difference in organic matter content, which ultimately affects the concentration of GDGTs. [ABSTRACT FROM AUTHOR]

• A comprehensive review of the current research status of microchannel heat sinks was conducted from the perspectives of channel configuration, secondary structure, combined structure, and special cooling agents. • An analysis of the heat transfer and flow characteristics of various microchannel heat sinks was conducted. • A comparison of the advantages and disadvantages of various microchannel heat sinks was made. Enhanced heat transfer technology can be divided into active technology and passive technology based on whether external power is consumed. Due to the absence of external energy consumption, passive technology is more reliable than active cooling technology. Microchannel heat sink (MCHS) are widely used for heat dissipation in the field of microelectronics. In recent years, due to the continuous miniaturization of electronic chips and the high heat flux per unit area (about 300 W/cm2), the passive enhanced heat transfer technology of microchannel heat sinks has developed rapidly. This article provides a comprehensive review of passive enhanced heat transfer technology in MCHS. It introduces the influence of channel configuration, secondary structure, combined structure, and different heat transfer media on the heat transfer capacity and pressure drop of microchannel heat sinks. Finally, a summary is given based on the collected data. [ABSTRACT FROM AUTHOR]

This study investigated microstructural changes in broad bean seeds at 0 and 8 °C at a vacuum degree of 97 kPa using an SEM. The cellular-morphology distributions changed obviously with time and temperatures. Although cell rupture occurred, higher temperatures caused more cells to contract more actively. The cell size was primarily affected by moisture content, while the cell shape was simultaneously influenced by temperature and moisture content. The diameter correlated well with moisture loss and shrinkage during dehydration (correlation coefficients > 0.96). However, the correlation was not strong (most correlation coefficients < 0.9) when the cell shape was considered. [ABSTRACT FROM AUTHOR]

This study aimed to assess the protective value of adiponectin (APN) in pancreatic islet injury induced by chronic intermittent hypoxia (CIH). Sixty rats were randomly divided into three groups: normal control (NC) group, CIH group, and CIH with APN supplement (CIH+APN) group. After 5 weeks of CIH exposure, we conducted oral glucose tolerance tests (OGTT) and insulin released test (IRT), examined and compared the adenosine triphosphate (ATP) levels, mitochondrial membrane potential (MMP) levels, reactive oxygen species (ROS) levels, enzymes gene expression levels of Ant1, Cs, Hmox1, and Cox4i1 which represented mitochondrial tricarboxylic acid cycle function, the protein and gene expression levels of DRP1, FIS1, MFN1, and OPA1 which represented mitochondrial fusion and division, and the protein expression levels of BAX, BCL-2, cleaved Caspase-3, and cleaved PARP which represented mitochondrial associated apoptosis pathway of pancreatic islet. OGTT and IRT showed blood glucose and insulin levels had no differences among the NC, CIH and CIH+APN groups (both P >0.05) at 0 min, 20 min, 30 min, 60 min, 120 min. However, we found that compared to NC group, CIH increased the ROS level, reduced ATP level and MMP level. The islets of CIH exposed rats showed reduced gene expression levels of Ant1 , Cs, Hmox1, and Cox4i1, decreased protein and gene expression levels of MFN1 and OPA1, increased protein and gene expression levels of DRP1 and FIS1, increased protein expression levels of cleaved Caspase-3 and cleaved PARP, with lower ratio of BCL-2/BAX at protein expression level. All the differences among three groups were statistically significant. APN treated CIH rats showed mitigated changes in the above measurements associated with islet injuries. APN may ameliorate the pancreatic islet injury induced by CIH via inhibiting the imbalance in mitochondrial fusion and division. [ABSTRACT FROM AUTHOR]

With the rapid development of information technology, data streams in various fields are showing the characteristics of rapid arrival, complex structure and timely processing. Complex types of data streams make the classification performance worse. However, ensemble classification has become one of the main methods of processing data streams. Ensemble classification performance is better than traditional single classifiers. This article introduces the ensemble classification algorithms of complex data streams for the first time. Then overview analyzes the advantages and disadvantages of these algorithms for steady-state, concept drift, imbalanced, multi-label and multi-instance data streams. At the same time, the application fields of data streams are also introduced which summarizes the ensemble algorithms processing text, graph and big data streams. Moreover, it comprehensively summarizes the verification technology, evaluation indicators and open source platforms of complex data streams mining algorithms. Finally, the challenges and future research directions of ensemble learning algorithms dealing with uncertain, multi-type, delayed, multi-type concept drift data streams are given. [ABSTRACT FROM AUTHOR]

[Display omitted] • Facile synthesis of anode material with organized structure. • Binary composite demonstrates better performance than its unitary counterpart. • In-situ XRD together with in-depth characterization reveals sodium ion storage. • DFT calculation verifies the sodium migration barrier. Sodium-ion batteries offer significant advantages in terms of low-temperature performance and safety. In this study, we present a straightforward synthetic approach to produce bimetallic selenide NiCoSe 2 nanoparticles grown on a three-dimensional porous carbon framework for application as anode materials in sodium-ion batteries. This unique architecture enhances reaction kinetics and structural stability. The three-dimensional interconnected porous carbon network establishes a continuous pathway of electronic conductive, while increasing specific surface area and mitigating volume expansion. Consequently, these features expedite ion transfer and enhance electrolyte interaction. Notably, compared to CoSe, NiCoSe 2 exhibits reduced ion transport distances and lower sodium diffusion barriers. Leveraging these attributes, NiCoSe 2 /N, Se co-doped carbon composite materials (NiCoSe 2 /NSC) demonstrate a high specific capacity of 320.8 mAh/g, even after 1000 cycles at 5.0 A/g, with a capacity retention rate of 85.1%. The study further delves into the revelation of the reaction mechanism and ion transport pathway through in-situ X-ray diffraction (XRD) analysis and theoretical calculations. The development of these anode materials is poised to pave the way for advancements in sodium-ion battery technology. [ABSTRACT FROM AUTHOR]

Acoustic array is a ubiquitous tool for locating and quantifying sound sources. However, its effectiveness depends greatly on the array configuration. This paper presents an array configuration method to enhance array performance, especially on the spatial resolution and the Doppler effect correction. The problem of array configuration is formulated into a position matrix determined by introducing partition spatial filtering. Irregular coaxial ring grid spacings and partition filtering conditions are suggested to control array spatial resolution. Geometrical parameters and performance indicators are constructed to quantify the relationships between the array configuration and performance. Based on these quantitative relations, the spatial variation of the array beam pattern and the Doppler effect has got adaptive adjustment. In particular, an adaptive partition algorithm is proposed to reduce computation time. The performance of the method is examined numerically and experimentally, which is compared with the other methods. The results provide the method to guide the design of a 64-microphone optimized array with high performance (1.8° spatial angle resolution and 40% Doppler frequency correction over the bandwidth from 800 Hz to 3000 Hz) and fast computing speed (18 s array generated time for 2000 arrays). Furthermore, an unusual feature of the method is that it can be utilized in the case when the source moves at a nonconstant velocity. [ABSTRACT FROM AUTHOR]

For passengers, the most common feeling during running on the bumpy road is continuous vertical discomfort, and when the vehicle is braking, especially the emergency braking, the instantaneous inertia of the vehicle can also cause a strong discomfort of the passengers, so studying the comfort of the vehicle during the braking process is of great significance for improving the performance of the vehicle. This paper presented a complete control scheme for vehicles equipped with the brake-by-wire (BBW) system aiming at ensuring braking comfort. A novel braking intention classification method was proposed based on vehicle braking comfort, which divided braking intention into mild brake, medium comfort brake, and emergency brake. Correspondingly, in order to improve the control accuracy of the vehicle brake system and to best meet the driver's brake needs, a braking intention recognizer relying on fuzzy logic was established, which used the road condition and the brake pedal voltage and its change rate as input, output real-time driver's braking intention, and braking intensity. An optimal brake force distribution strategy for the vehicle equipped with the BBW system based on slip rate was proposed to determine the relationship between braking intensity and target slip ratio. Combined with the vehicle dynamics model, improved sliding mode controller, and brake force observer, the joint simulation was conducted in Simulink and CarSim. The cosimulation results show that the proposed braking intention classification method, braking intention recognizer, brake force distribution strategy, and sliding mode control can well ensure the braking comfort of the vehicle equipped with the BBW system under the premise of ensuring brake safety. [ABSTRACT FROM AUTHOR]

The steady state heat transfer and flow resistance performance in cosine style runners with different amplitudes are studied numerically and experimentally in this paper. The results show that: When the Reynolds numbers (Re) range from 1210 to 5080, the core volume goodness factor (ηohstdα) is used to compare the overall heat transfer performance of the two runners, and the ηohstdα value in the cosine style runner is 7–25% larger than that of the equal cross section runner, so that the cosine style runner has better overall heat transfer enhancement performance. When the amplitudes (2A) range from 5 to 9 mm, with the decrease of amplitude, the overall heat transfer performance is getting better. At the same amplitude, the convective heat transfer performance gradually increases as the inlet height (Fh) decreases; with the increase of Re, the thickness of the thermal and velocity boundary layers are both decreasing. Based on the field synergy principle, the heat transfer enhancement mechanisms with different parameters are evaluated, and we conclude that the smaller the amplitude is, its field synergy is better. [ABSTRACT FROM AUTHOR]

Due to deeper buried, multi-stage tectonic influences, rapid changing, and unclear originate of oil and gas in Jinlong 2 wellblock, we analyzed the volcanic reservoir characteristics and the genesis of hydrocarbon by cores, thin slices, loggings, physical properties, oil testing data, and carbon isotopes. Results demonstrated that the major lithology were pyroclastic rocks and lavas, the reservoir was generally poor and strongly homogeneous, the main reservoir space were primary pores, and the favorable reservoir mainly developed in the pyroclastic rocks of the third phase. Furthermore, the results of carbon isotopes indicated that the crude oil and dissolved gas originated from Fengcheng formation, while the condensate gas derived from Jiamuhe formation. [ABSTRACT FROM AUTHOR]

The laminar convective flow and heat transfer in trapezoidal ducts with a rectangular cross-section are studied numerically. Under certain conditions, the temperature difference distribution and pressure drop in trapezoidal ducts are better than that of in rectangular ducts, which leads to an advantage of heat transfer enhancement. At the same heat transfer area, the maximum Colburn (j) factor in trapezoidal ducts increases by 8% when compared with a rectangular duct, and the minimum friction (f) factor decreases by 22.6%. The numerical data also shows that the thermal-hydraulic characteristics for trapezoidal ducts first increases and then decreases while slope angle (β) increases. The airflow is disturbed at the wall showing recirculation flow and separation when β = 30°, but the thermal-hydraulic performance starts to decrease when β > 40°. In a word, the thermal-hydraulic characteristics of trapezoidal ducts are better than that of rectangular ducts when β ≤ 40°. On the contrary, When β > 40°, the rectangular duct has a better performance than that of trapezoidal ducts. The applicability of the above conclusions is proved by using the taguchi method. [ABSTRACT FROM AUTHOR]

Introduction Central sleep apnea (CSA) is common in patients with heart failure (HF) and is associated with poor quality of life and prognosis. Early acute studies using transvenous phrenic nerve stimulation (PNS) to treat CSA in HF have shown a significantly reduction of CSA and improvement of key polysomnographic parameters. In this study, we evaluated the safety of and efficiency chronic transvenous PNS with an implanted neurostimulator in HF patients with CSA. Methods This study was a prospective, nonrandomized evaluation of unilateral transvenous PNS in eight HF patients with CSA. The stimulation lead, which connected to a proprietary neurostimulator, was positioned in either the left pericardiophrenic or right brachiocephalic vein. Monitoring during implantation and 6-monthly follow-ups were performed. Results Six of the implanted eight patients completed the study (one was lost to follow-up; one died from pneumonia). Neither side effects nor adverse events related to stimulation occurred. During the 6-monthly follow-ups, one patient had a lead dislodgement in the first month and the lead was subsequently repositioned. No additional lead dislodgements occurred. There were no significant changes in sleep habits, appetite, bleeding or infections. Compared with the parameters before stimulator implantation, there were significant improvement in apnea-hypopnea index, central apnea index, left ventricular ejection fraction and 6-min walk distance (all P < 0.01). Conclusions Use of chronic transvenous PNS appears to be safe and feasible in HF patients with CSA. Large multicenter studies are needed to confirm safety and efficacy in this population. [ABSTRACT FROM AUTHOR]

Convective heat and mass transfer are common phenomena in the field of engineering. In recent years, the research on convective heat and mass transfer is getting deeper and deeper. People are constantly seeking new methods to improve the efficiency of heat and mass transfer, but the research on the mechanism of heat and mass transfer is not yet systematic and mature. The theory of the field synergy has made up for this research gap, but the research progress and application of its heat and mass transfer theory lack systematic summary and evaluation. This paper summarizes the theory of enhanced heat and mass transfer based on field synergy theory, analyzes the field synergy equation of heat transfer, mass transfer, and heat-mass cooperation under laminar and turbulent conditions, and gives the evaluation standard of field synergy equation. Field synergy theory shows that improving the synergy between the velocity field and temperature gradient field, that is, reducing the angle between them, can effectively improve the heat transfer efficiency, and improving the synergy between the velocity field and concentration gradient field can effectively improve the mass transfer efficiency. Subsequently, the research progress of field synergy theory in different engineering fields is summarized. It is shown that field synergy theory can be used to analyze the cooperation between fields in heat exchangers, micro-components, nanofluids, reactors and other fields to guide the optimal design of equipment, which proves the universality of field cooperation theory. Finally, in view of the universality of the damp-heat exchange in the cooling exchangers and the research object of field synergy theory, a new idea of using the field synergy theory to guide the research on the structural design of cooling exchangers is put forward, which provides new ideas and methods for effectively improving the underground humid and thermal environment. [ABSTRACT FROM AUTHOR]

Nanofluids have been widely used in various fields because of their unique thermal conductivity. This paper reviews and evaluates the thermal conductivity of nanofluids according to the recent literatures on the thermal conductivity of nanofluids. The results showed that in recent years, with the support of multiple disciplines, many new nanofluids have been prepared, such as cellulose nanofluids, graphene nanofluids, etc. These nanofluids have even better thermal conductivity. In terms of the prediction of thermal conductivity of nanofluids, neural network prediction has high accuracy and low time cost, so it is believed that it will become the main prediction method in the future. Although the experiments and studies of nanofluids have been carried out, there is no comprehensive review on the thermal conductivity of nanofluids from various aspects. In order to solve this problem, the research on nanofluids in recent years is reviewed from three aspects: influencing factors, prediction models and applications. The prediction models of thermal conductivity of nanofluids are introduced emphatically and each prediction model is evaluated. The neural network prediction models in recent years are discussed in detail. The purpose of this paper is to give a complete and detailed description of the thermal conductivity of nanofluids, as a reference for researchers to understand and study the thermal conductivity of nanofluids, and to update the latest research results in a timely manner. It is hoped to point out the direction for the research of nanofluids in the future. [ABSTRACT FROM AUTHOR]

The heat transfer and pressure drop performance of magnetic nanofluids (MNFs) under different alternating magnetic fields were investigated experimentally. The results showed that the effect of alternating magnetic field on local heat transfer coefficient is better than that of unidirectional and non-magnetic fields along flow direction. The local heat transfer coefficient in the rear of the flow channel has a greater promoting capacity than that in the front. The heat transfer performance is higher at a lower Reynolds number (Re), but worse at a higher Re. Heat transfer coefficient always increases with the increase of volume fraction with or without alternating magnetic fields. When the volume fraction is among 1 vol%-3 vol%, the greater the alternating frequency is, the better the heat transfer performance will be. When the volume fraction is greater than 3 vol%, increasing the frequency of alternating magnetic field has little effect on heat transfer performance. For magnetic nanofluids with different volume fractions and different magnetic fields, they also show quadratic variation rules. The larger the volume fraction and magnetic field frequency are, the greater the pressure drop will be. The improvement of the overall heat transfer performance increases first and then decreases when the alternating frequencies and Reynolds numbers increase. The reasons for the improvement of the heat transfer are the movement and accumulation of magnetic nanoparticles at the thermal boundary layer, and the eddy action of MNFs. • Effect of alternating magnetic field on heat transfer coefficient is better than that of unidirectional fields. • Heat transfer coefficient increases with the increase of alternating frequency and volume fraction. • Factors that enhance heat transfer are particle motion, accumulation, vortex flow, and thermal boundary layer. • The larger the volume fraction and magnetic field frequency are, the greater the pressure drop will be. • The overall heat transfer performance increases first and then decreases. [ABSTRACT FROM AUTHOR]

Numerical simulations were adopted to explore the heat transfer and flow characteristics of magnetic nanofluids under different magnetic field intensities, volume fractions, and magnetic field directions. Due to these parameters have a significant effect on thermal hydraulic performance and the mechanism of this enhancement are not yet clear, a turbulent model of Re-normalization group (RNG) k-ε is used to analyze the variation of thermal boundary layer and particle motion. The obtained results found that the effect of heat transfer enhancement was small under a weak magnetic field, but it increased considerably under a strong magnetic field. Besides, the convection heat transfer coefficient initially increased and then decreased with an increase of volume fractions of magnetic nanoparticles. Moreover, the directions of the magnetic field have a significant effect on convective heat transfer coefficient, which results in 8% increase when the direction is perpendicular to direction of flow. [ABSTRACT FROM AUTHOR]

With the increasing application of heat exchangers, the research has become increasingly comprehensive. Previous studies mainly focused on comparing the amplitudes to investigate the performance of heat exchangers, while the study of variable amplitude channel structures was limited. This study investigated the thermal-hydraulic performance of seven different sinusoidal channels with inclination angles of 20° and 30°, and their combinations. Using the CFD solver, simulations were conducted to assess the heat transfer capabilities of sinusoidal channels under various Reynolds numbers and different amplitude conditions, compared to straight channels and single amplitude sinusoidal channels. The results indicated that within one period, both the pressure drop and temperature difference exhibited a ripple trend of gradually decreasing amplitude. When evaluating the comprehensive performance of the channels, three trends emerged across the seven models, with the performance of the cold fluid and the hot fluid within the same group showing opposite trends. This suggested that more variations could enhance the overall performance of the hot fluid while reducing the performance of the cold fluid. For structures with the same amplitude, in terms of amplitude variation frequency, models with six periods per group exhibited higher overall heat transfer performance than those with three periods per group, with an average increase of 36.37%. For the arrangement of amplitudes (taking the hot fluid inlet as an example), configurations with a smaller amplitude at the inlet outperformed those with a larger amplitude, indicating that in combined amplitude models, a structure with a larger group and a smaller amplitude at the inlet (taking the hot fluid as an example) should be designed. [ABSTRACT FROM AUTHOR]

The heat transfer and flow characteristics of the air-water cross flow over cambered ducts were experimental and numerical investigated. The sequence of their Core Volume Goodness Factor (CVGF) is cosinoidal, parabolic, circular, trapezoidal and rectangular ducts successively from superior to inferior. Cambered ducts have more uniform temperature difference distribution than the equal cross section duct, and it has the minimum temperature difference in inlet and outlet of the cosinoidal duct. With the optimal overall heat transfer performance, the cosinoidal duct is superior to that of the rectangular duct by 7.3%–28.1%. In the cosinoidal duct, the smaller the amplitude is, the better the heat transfer performance is. The thickness of the thermal and velocity boundary layers adjacent to the wall surface decreases constantly with increased Reynolds number. In the near wall region, n = 5 um , the main heat transfer area is the peak and middle areas, but with weaker heat transfer performance in the trough region. Although gradually expanding cambered duct slows down the flow velocity, the structure form decreases the pressure drop loss during the flow process. While improving the convective heat exchange capability of the upstream, the heat transfer area of the downstream is also improved to boost the overall heat transfer performance. • Performance in divergent cambered ducts are better than that of equal cross section duct. • The cambered ducts have uniform temperature difference distribution. • The smaller the amplitude is, the better overall heat transfer performance is. • Temperature gradient in the peak region is bigger than that in the trough region. [ABSTRACT FROM AUTHOR]

• The performance in parabolic duct is better than that of trapezoidal duct. • Divergent duct can improve heat transfer performance. • The overall heat transfer performance decreases with the increase of focal length. • The parabolic duct has uniform temperature difference distribution. In this paper, the heat transfer and flow characteristics of parabolic ducts with different focal lengths (P = 120 mm, 140 mm, and 160 mm) are analyzed and compared with rectangular and trapezoidal ducts respectively. The governing equations in the curved ducts, including the mass conservation equation, momentum equation and energy conservation equation, are established. The results show that the order of the overall heat transfer performance of the three ducts from the best to worst is parabolic duct, trapezoidal duct and rectangular duct. The parabolic duct has the best overall enhanced heat transfer performance, which is 5.1% and 25.4% larger than that of the trapezoidal and the rectangular ducts respectively. This means that, although the divergent type structure reduces the flow velocity and thus weakens the intensity of convective heat transfer in the duct, it improves the downstream heat transfer area and reduces the pressure drop loss in the flow process, thus promoting the improvement of overall heat transfer performance. Besides, the temperature difference in the parabolic flow duct has the most uniform distribution, which is an important factor to improve and strengthen heat transfer performance. From the perspective of field synergy theory, the average field synergy angle decreases with the increase of focal length, and the field synergy becomes better. [ABSTRACT FROM AUTHOR]

In previous literature, the realization of topological interface state in one-dimensional periodic system is strongly relied on the tedious parameter adjustment to search for the Dirac cone. In this paper, based on a strategy of zone folding, multiple topological interface modes for the shear horizontal guided waves in one dimensional phononic crystal plate are investigated by using finite element method and eigenmode matching theory, in which the Dirac points are formed by simply making the unit cell double. Significantly, by simply contracting or expanding the stubs can bring the topological phase transition. Furthermore, the topological phase transition is further achieved by varying the height of the stubs. The proposed designs will be more convenient to be applied in real engineering. • By the band folding, multiple topological interface modes for the shear horizontal guided waves are investigated. • By contracting or expanding the stubs can bring the band inversion effect, giving rise to the topological phase transition. • The topological phase transition is further achieved by another homologous way of varying the height of the stubs. • All the simulation results by the finite element method are verified by the theoretical method of eigenmode matching theory. [ABSTRACT FROM AUTHOR]

A curved heat transfer surface is proposed to improve the condensation process. The flow performance and condensation law in the cosine-shaped flow channel, a special curved surface, are numerically and theoretically studied. A theoretical model of surface filmwise condensation on a curved flow channel is established and the mathematical model is validated. The liquid film thickness equation in different zones of the curved surface is deduced and calculated. The results show that the main condensation heat transfer zone is in the middle zone (25 mm < s < 45 mm) and the wave crest zone (0 mm ≤ s ≤ 25 mm), the temperature gradient of the liquid film surface decreases along the liquid flow direction, and the liquid film thickness becomes thinner with the increase of steam velocity. [ABSTRACT FROM AUTHOR]

Abstract The study of the heat exchangers in the trapezoidal channels and the rectangular channels were carried out. The trapezoidal channel has smaller friction resistance than the rectangular channel with equal section, and the friction factor (f) decreases gradually with the increase of inclination angle, when β= 25 °, the f is the smallest, which is reduced by nearly 22.6% compared to the rectangular channel with equal cross-section; when , the heat transfer factor (j) and comprehensive heat transfer performance of the trapezoidal channel are greater than those of the rectangular channel with the same section, and when , those increase by 8% and 20%, respectively. The height and length of fins have a significant impact on heat transfer performance, increased by 17.65% and 20.85% respectively; By analyzing the comprehensive performance of the trapezoidal channel, the # 8 structure (Fh=10.5mm, β=5°, Sf=3mm, Lf=45mm, tf=0.3mm) has the optimal performance. [ABSTRACT FROM AUTHOR]

In this paper, an electromagnetic energy-regenerative suspension system is proposed to achieve active control and vibration energy harvesting. For this system, a PID controller based on BP neural network algorithm is designed and vehicle dynamic performances are studied. Based on the traditional energy-regenerative efficiency calculation, a novel self-supply energy efficiency concept is proposed to evaluate the utilization effect of the recycled energy for this dual-functional suspension. Simulations are carried out, and the results show that the vehicle dynamic performances are effectively improved under different input conditions, including road surfaces and vehicle speeds. Furthermore, the energy-regenerative suspension can recover part of vibration energy, where the self-supply energy efficiency is about 55% and the energy-regenerative efficiency is about 16%. Meanwhile, the BP-PID algorithm also enables the suspension system's self-adaptability and stability characteristics on its energy recovery capability. [ABSTRACT FROM AUTHOR]

With mining activities penetrating ever deeper, the consequences of high temperature in mines are increasingly difficult to manage. In this work, a composite thermal barrier coating consisting of an air-curing, heat resistant coating and a polyurethane foaming plastic layer is developed. The influence of coating thickness and porosity on the insulation performance is computed with analysis and simulation. A testing device to measure the thermal conductivity coefficient of the coating is also designed to evaluate its properties. [ABSTRACT FROM AUTHOR]

Background: Geographic differences exist in the antibiotic resistance patterns of Helicobacter pylori. Personalized treatment regimens based on local or individual resistance data are essential. We evaluated the current status of H. pylori resistance in Ningxia, analyzed resistance‐related factors, and assessed the concordance of phenotypic and genotypic resistance. Methods: Strains were isolated from the gastric mucosa of patients infected with H. pylori in Ningxia and relevant clinical information was collected. Phenotypic antibiotic susceptibility assays (Kirby–Bauer disk diffusion) and antibiotic resistance gene detection (Sanger sequencing) were performed. Results: We isolated 1955 H. pylori strains. The resistance rates of H. pylori to amoxicillin, levofloxacin, clarithromycin, and metronidazole were 0.9%, 42.4%, 40.4%, and 94.2%, respectively. Only five tetracycline‐resistant and one furazolidone‐resistant strain were identified. Overall, 3.3% of the strains were sensitive to all six antibiotics. Multidrug‐resistant strains accounted for 22.9%, of which less than 20% were from Wuzhong. Strains isolated from women and patients with nonulcerative disease had higher rates of resistance to levofloxacin and clarithromycin. Higher rates of resistance to metronidazole, levofloxacin, and clarithromycin were observed in the older age group than in the younger age group. The kappa coefficients of phenotypic resistance and genotypic resistance for levofloxacin and clarithromycin were 0.830 and 0.809, respectively, whereas the remaining antibiotics showed poor agreement. Conclusion: H. pylori antibiotic resistance is severe in Ningxia. Therefore, furazolidone, amoxicillin, and tetracycline are better choices for the empirical therapy of H. pylori infection in this region. Host sex, age, and the presence of ulcerative diseases may affect antibiotic resistance of the bacteria. Personalized therapy based on genetic testing for levofloxacin and clarithromycin resistance may be a future direction for the eradication therapy of H. pylori infection in Ningxia. [ABSTRACT FROM AUTHOR]

Microstructural changes in broad bean seeds during dehydration can explain interactions between intercellular voids and cells for better seed storage. However, considering the limited research, herein, changes in intercellular voids and cells in broad bean seeds during dehydration were evaluated. Broad beans were dehydrated at 0 °C and 8 °C and vacuum >97 kPa. Cell area reduction and void area increase were observed; the average cell area in fresh samples was 10,867 μm2, which was much larger than the void area. Despite overall decreasing moisture content, the size, porosity, and fractal dimensions of cells and voids fluctuated across samples. Thus, changes in intercellular voids and cells affect each other. Furthermore, decreases in cell turgor and rupture had a significant impact on intercellular void structure and size, and changes in cell fractal dimensions were highly correlated with cell size. Combined with previous findings, this study provides insights into cell and intercellular void development. [ABSTRACT FROM AUTHOR]

Most of the thermal management for the battery energy storage system (BESS) adopts air cooling with the air conditioning. However, the air-supply distance impacts the temperature uniformity. To improve the BESS temperature uniformity, this study analyzes a 2.5 MWh energy storage power station (ESPS) thermal management performance. It optimizes airflow organization with louver fins and simulates its heat transfer behavior. To improve the flow rate distribution along the airflow passage, the air-supply organization of louver fins for the overhead air conditioner is optimized. It indicates that the air-supply angle (A) for louver fins and the battery spacing (D) impacts greatly on BESS thermal management performance. The air supply optimal organization with the A of 90° and the D of 18mm was determined, of which the average temperature (TA) rise of the battery can be reduced by 18%, and the temperature difference (TD) is decreased by 23%. Furthermore, a multi-parametric sensitivity analysis is conducted, and the different heat-flow parameter influential sequence for the TA and TD are revealed. The air supply volume flow rate (L) and the air supply temperature (AST) has a significant effect on the TA reduction, and the AST shows significance on the TD decreasing. When AST is reduced to 290 K, the TA rise of batteries decreased by 71%. When the L is increased 10 times, the TA rise of batteries decreased by 227%. When the AST is decreased to 290 K, the TD is reduced by 39%. When the L for air supply is increased by 10 times, the TD will increase by 28%. In this research, the louver fins are firstly adopted for orifices air supply organization to improve thermal field uniformity for BESS. [ABSTRACT FROM AUTHOR]

The concept drift detection method is an online learner. Its main task is to determine the position of drifts in the data stream, so as to reset the classifier after detecting the drift to improve the learning performance, which is very important in practical applications such as user interest prediction or financial transaction fraud detection. Aiming at the inability of existing drift detection methods to balance the detection delay, false positives, false negatives, and space–time efficiency, a new level transition threshold parameter is proposed, and a multi-level weighted mechanism including "Stable Level-Warning Level-Drift Level" is innovatively introduced in the concept drift detection. The instances in the window are weighted in levels, and the double sliding window is also applied. Based on this, a multi-level weighted drift detection method (MWDDM) is proposed. In particular, two variants which are MWDDM_H and MWDDM_M are proposed based on Hoeffding inequality and Mcdiarmid inequality, respectively. Experiments on artificial datasets show that MWDDM_H and MWDDM_M can detect abrupt and gradual concept drift faster than other comparison algorithms while maintaining a low false positive ratio and false negative ratio. Experiments on real-world datasets show that MWDDM has the highest classification accuracy in most cases while maintaining good space time efficiency. [ABSTRACT FROM AUTHOR]

The relationship between mafic magmatic enclaves (MMEs) and host granitoids is ongoing debate due to their significant roles in understanding deep magmatisms and geodynamic processes. This paper reports on Early Palaeozoic granitoids and associated MMEs from the Delingha pluton in the South Qilian Accretionary Belt (NW China) to constrain their petrogenesis and draw implications. The MMEs, occurring as ellipsoidal to rounded shapes, are andesitic and have the same crystallization age (~445 Ma) and mineral assemblage as the host granitoids. However, minor isotopic differences between them and compositional and textural disequilibria on minerals (e.g. plagioclase and amphibole) do not support a cumulate origin that the MMEs were formed at earlier stage of the same magmatic system, but forcefully reflect magma hybridization processes between mafic and felsic magmas, during which the hybridized magma was broken up into discrete enclaves by convective motion in the host felsic magma. Accordingly, the primitive compositions of the MMEs likely originated from metasomatized mantle wedge source, while mantle-derived melt underplated and partially melted the lower continental crust to form the host rocks with a certain mantle contribution. Thus, the Delingha pluton is the product of crust-mantle interaction at an active continental margin subduction setting rather than syn-collisional environment, indicating that subduction of the South Qilian Ocean located between the Central Qilian Block and the Oulongbuluke Block may have lasted till to ~445 Ma. [ABSTRACT FROM AUTHOR]

At present, concept drift in the nonstationary data stream is showing trends with different speeds and different degrees of severity, which has brought great challenges to many fields like data mining and machine learning. In the past two decades, a lot of methods dedicated to handling concept drift in the nonstationary data stream have emerged. A novel perspective is proposed to classify these methods, and the current concept drift handling methods are comprehensively explained from the active handling methods and the passive handling methods. In particular, active handling methods are analyzed from the perspective of handling one specific type of concept drift and handling multiple types of concept drift, and passive handling methods are analyzed from the perspective of single learner and ensemble learning. Many concept drift handling methods in this survey are analyzed and summarized in terms of the comparing algorithms, learning model, applicable drift type, advantages, and disadvantages of the algorithms. Finally, further research directions are given, including the active and passive mixing methods, class imbalance, the existence of novel class in the data stream, and the noise in the data stream. [ABSTRACT FROM AUTHOR]

• Used a novel multi-link conversion mechanism on the active suspension. • Analyzed the 2-DOF mechanism conversion characteristics. • Introduced a new parameter value K , simplifying the mechanism model expression. • Calculated the energy-regenerative and self-supplying efficiency. In this paper, a new energy-regenerative suspension system with a simplified multi-DOF mechanism was proposed. The research firstly focuses on characteristics of the transmission and conversion analysis, and energy recovery calculation. Then the relationship between the vibration amplitude and the rotation angle is computed and simulated. The dead angle of motion is found. A novel parameter K is proposed to describe the outer profile envelope of the linkages for the first time, which provides a potential reduction for the control matrix dimension. A 2-DOF suspension model, integrated with the multi-link rotating electromagnetic regenerative shock absorber, is built, simulated, and analyzed. The kernel simulation results are validated by experiments at last. Driving on Class B road, the results show that the energy-regenerative suspension controlled by the LQG algorithm is 20.56% smaller than the passive suspension in Body Acceleration; the energy regeneration efficiency is 14.28%, and the self-supply efficiency is 54.66%. Comparing to the ball-screw structure, we increase the energy harvesting ratio by 21.43% with similar control effects. The research provides new ideas for suspension design and control, reduces energy consumption, and improves ride comfort and driving stability as well. [ABSTRACT FROM AUTHOR]

Objective: Despite evidence of a relationship among obstructive sleep apnea (OSA), metabolic dysregulation, and diabetes, it is uncertain whether OSA treatment can improve metabolic parameters. We sought to determine effects of long-term continuous positive airway pressure (CPAP) treatment on glycemic control and diabetes risk in patients with cardiovascular disease (CVD) and OSA.Research Design and Methods: Blood, medical history, and personal data were collected in a substudy of 888 participants in the Sleep Apnea cardioVascular Endpoints (SAVE) trial in which patients with OSA and stable CVD were randomized to receive CPAP plus usual care, or usual care alone. Serum glucose and glycated hemoglobin A1c (HbA1c) were measured at baseline, 6 months, and 2 and 4 years and incident diabetes diagnoses recorded.Results: Median follow-up was 4.3 years. In those with preexisting diabetes (n = 274), there was no significant difference between the CPAP and usual care groups in serum glucose, HbA1c, or antidiabetic medications during follow-up. There were also no significant between-group differences in participants with prediabetes (n = 452) or new diagnoses of diabetes. Interaction testing suggested that women with diabetes did poorly in the usual care group, while their counterparts on CPAP therapy remained stable.Conclusions: Among patients with established CVD and OSA, we found no evidence that CPAP therapy over several years affects glycemic control in those with diabetes or prediabetes or diabetes risk over standard-of-care treatment. The potential differential effect according to sex deserves further investigation. [ABSTRACT FROM AUTHOR]

In recent years, there are more and more applications of traffic violation monitoring in some countries. The present work aims to analyze the vehicle speeds nearby road traffic violation monitoring area on urban main roads and find out the impact of road traffic violation monitoring on the vehicle speeds. A representative urban main road section was selected and the traffic flow was recorded by camera method. The vehicle speeds before, within, and after the road traffic violation monitoring area were obtained by the calculation method. The speed data was classified and processed by SPSS software and mathematical method to establish the vehicle speed probability density models before, within, and after the road traffic violation monitoring area. The results show that the average speed and maximum speed within the traffic violation monitoring area are significantly slower than those before and after the traffic violation monitoring area. 70.1% of the vehicles before the road traffic violation monitoring area were speeding, and 80.2% of the vehicles after the road traffic violation monitoring area were speeding, while within the road traffic violation monitoring area, the speeding vehicles were reduced to 15.9%. When vehicles pass through the road traffic violation monitoring area, the vehicle speeds tend to first decrease and subsequently increase. In its active area, road traffic violation monitoring can effectively regulate driving behaviors and reduce speeding, but this effect is limited to the vicinity of the traffic violation monitoring. The distribution of vehicle speeds can be calculated from vehicle speed probability density models. [ABSTRACT FROM AUTHOR]

Background: Although recent evidence suggests that OSA treatment may cause weight gain, the long-term effects of CPAP on weight are not well established.Methods: This study was a post hoc analysis of the Sleep Apnea Cardiovascular Endpoints (SAVE) study, a multicenter, randomized trial of CPAP plus standard care vs standard care alone in adults with a history of cardiac or cerebrovascular events and moderate to severe OSA. Participants with weight, BMI, and neck and waist circumferences measured at baseline and during follow-up were included. Linear mixed models were used to examine sex-specific temporal differences, and a sensitivity analysis compared high CPAP adherers (≥ 4 h per night) with propensity-matched control participants.Results: A total of 2,483 adults (1,248 in the CPAP group and 1,235 in the control group) were included (mean 6.1 ± 1.5 measures of weight available). After a mean follow-up of 3.78 years, there was no difference in weight change between the CPAP and control groups, for male subjects (mean [95% CI] between-group difference, 0.07 kg [-0.40 to 0.54]; P = .773) or female subjects (mean [95% CI] between-group difference, -0.14 kg [-0.37 to 0.09]; P = .233). Similarly, there were no significant differences in BMI or other anthropometric measures. Although male participants who used CPAP ≥ 4 h per night gained slightly more weight than matched male control subjects without CPAP (mean difference, 0.38 kg [95% CI, 0.04 to 0.73]; P = .031), there were no between-group differences in other anthropometric variables, nor were there any differences between female high CPAP adherers and matched control subjects.Conclusions: Long-term CPAP use in patients with comorbid OSA and cardiovascular disease does not result in clinically significant weight change.Trial Registry: ClinicalTrials.gov; No.: NCT00738179; URL: www.clinicaltrials.gov. [ABSTRACT FROM AUTHOR]

Background: Genioglossal dysfunction is involved in the pathophysiology of obstructive sleep apnea hypoxia syndrome (OSAHS) characterized by nocturnal chronic intermittent hypoxia (CIH). The pathophysiology of genioglossal dysfunction and possible targeted pharmacotherapy for alleviation of genioglossal injury in CIH require further investigation. Methodology/Principal Findings: Rats in the control group were exposed to normal air, while rats in the CIH group and CIH+adiponectin (AD) group were exposed to the same CIH condition (CIH 8 hr/day for 5 successive weeks). Furthermore, rats in CIH+AD group were administrated intravenous AD supplementation at the dosage of 10 µg, twice a week for 5 consecutive weeks. We found that CIH-induced genioglossus (GG) injury was correlated with mitochondrial dysfunction, reduction in the numbers of mitochondrias, impaired mitochondrial ultrastructure, and a reduction in type I fibers. Compared with the CIH group, impaired mitochondrial structure and function was significantly improved and a percentage of type I fiber was elevated in the CIH+AD group. Moreover, compared with the control group, the rats’ GG in the CIH group showed a significant decrease in phosphorylation of LKB1, AMPK, and PGC1-α, whereas there was significant rescue of such reduction in phosphorylation within the CIH+AD group. Conclusions: CIH exposure reduces mitochondrial biogenesis and impairs mitochondrial function in GG, while AD supplementation increases mitochondrial contents and alleviates CIH-induced mitochondrial dysfunction possibly through the AMPK pathway. [ABSTRACT FROM AUTHOR]

Obstructive sleep apnea syndrome (OSAS) is associated with many cardiovascular disorders such as heart failure, hypertension, atherosclerosis, and arrhythmia and so on. Of the many associated factors, chronic intermittent hypoxia (CIH) in particular is the primary player in OSAS. To assess the effects of CIH on cardiac function secondary to OSAS, we established a model to study the effects of CIH on Wistar rats. Specifically, we examined the possible underlying cellular mechanisms of hypoxic tissue damage and the possible protective role of adiponectin against hypoxic insults. In the first treatment group, rats were exposed to CIH conditions (nadir O2, 5–6%) for 8 hours/day, for 5 weeks. Subsequent CIH-induced cardiac dysfunction was measured by echocardiograph. Compared with the normal control (NC) group, rats in the CIH-exposed group experienced elevated levels of left ventricular end-systolic dimension and left ventricular end-systolic volume and depressed levels of left ventricular ejection fraction and left ventricular fractional shortening (p<0.05). However, when adiponectin (Ad) was added in CIH + Ad group, we saw a rescue in the elevations of the aforementioned left ventricular function (p<0.05). To assess critical cardiac injury, we detected myocardial apoptosis by Terminal deoxynucleotidyl transfer-mediated dUTP nick end-labeling (TUNEL) analysis. It was showed that the apoptosis percentage in CIH group (2.948%) was significantly higher than that in NC group (0.4167%) and CIH + Ad group (1.219%) (p<0.05). Protein expressions of cleaved caspase-3, cleaved caspase-9, and cleaved-caspase-12 validated our TUNEL results (p<0.05). Mechanistically, our results demonstrated that the proteins expressed with endoplasmic reticulum stress and the expression of reactive oxygen species (ROS) were significantly elevated under CIH conditions, whereas Ad supplementation partially decreased them. Overall, our results suggested that Ad augmentation could improve CIH-induced left ventricular dysfunction and associated myocardial apoptosis by inhibition of ROS-dependent ER stress. [ABSTRACT FROM AUTHOR]

Background: The associations between Rad51 gene polymorphisms (G135C and G172T) and risk of cancer have been investigated, but the results were inconclusive. To get a comprehensive evaluation of the association above, we performed a meta-analysis of published studies. Methods: A computerized search of PubMed, Embase and Web of Knowledge databases for all relevant studies was performed and the data were analyzed in a meta-analysis. The overall odds ratio (OR) with the 95% confidence interval (95% CI) was calculated to assess the strength of the association between Rad51 polymorphisms and cancer risk. Data were analyzed using fixed- or random-effects model when appropriate. Sensitivity analysis and publication bias test were also estimated. Results: Overall, a total of 54 case-control studies were included in the current meta-analysis, among which 42 studies with 19,142 cases and 20,363 controls for RAD51 G135C polymorphism and 12 studies with 6,646 cases and 6,783 controls for G172T polymorphism. For G135C polymorphism, the pooled results indicated that significantly increased risk was found in overall cancers (homozygote model: OR = 1.776, 95% CI = 1.288–2.449; allelic genetic model: OR = 1.169, 95% CI = 1.016–1.345; recessive model: OR = 1.946, 95% CI = 1.336–2.835), especially in breast cancer (homozygote model: OR = 1.498, 95% CI = 1.026–2.189; recessive model: OR = 1.732, 95% CI  =  1.170–2.562). For G172T polymorphism, a decreased cancer risk was observed in head and neck cancer (homozygote model: OR  =  0.621, 95% CI  =  0.460–0.837; allelic genetic model: OR  =  0.824, 95% CI  =  0.716–0.948; recessive model: OR  =  0.639, 95% CI = 0.488–0.837). Conclusions: Our results suggested that the Rad51 G135C polymorphism is a candidate for susceptibility to overall cancers, especially to breast cancer, and that the Rad51 G172T might play a protective role in the development of head and neck cancer. [ABSTRACT FROM AUTHOR]

The geochemical characteristics and distribution of saline lacustrine source rocks are shaped up by the environment and conditions under which they develop. Such environments, in turn, are often heavily influenced by various salt minerals and clay minerals. Therefore, the current study aims to investigate the potential impact of common salt minerals and clays on the formation and chemical changes of source rocks in salt lakes. Instead of relying on conventional classification methods that emphasize salinity, this study divides common petroleum-bearing saline lacustrine sedimentary basins into two types, the carbonate-type and the sulfate-type, based on the hydrochemistry of salt lakes. Experimental comparison of inorganic geochemistry between samples from modern and ancient saline lacustrine sedimentary systems revealed key differences in ion composition, and resultantly in the sedimentary sequences of salt minerals, the transformation of clay minerals, and the evolution of source rocks. It is found that CaCO 3 -bearing minerals are the first to precipitate in both types of salt lakes. However, secondary mineral deposition in carbonate-type saline lacustrine systems features the precipitation of Na 2 CO 3 -bearing alkaline minerals due to the depletion of Ca2+. Meanwhile, the clay in carbonate-type salt lakes contains a relatively high level of smectite and mixed-layer illite/smectite, as well as low content of illite, implying an impediment in smectite illitization. In contrast, sulfate-type salt lakes are enriched in Ca2+ but depleted in CO 3 2−, leading to the abundant development of Ca-bearing sulfate mineral deposits such as gypsum. These geochemical differences could be responsible for the propensity of carbonate-type salt lakes to harbor well-developed oil shale, and for the tendency of source rocks deposited in sulfate-type lacustrine systems to produce oils at the immature stage. • Hydrochemical classification is proposed to study saline lacustrine source rocks. • CO 3 2− delays carbonate-type lacustrine sedimentary system's smectite illitization. • CO 3 2− and Ca-bearing sulfate minerals may play key role in hydrocarbon generation. [ABSTRACT FROM AUTHOR]

A fourth-order Σ Δ modulator (SDM) applied for micro-electro-mechanical systems (MEMS) digital geophones is presented in this paper. At the system stage, the proposed fourth-order SDM adopts a hybrid path technology including a feedforward path and a feedback path. At the design stage, a class AB operational transconductance amplifier with a gain bootstrap structure and chopper technique is employed in the first-stage integrator, which can achieve high DC gain, GBW, (Slew Rate) SR and reduce flicker noise, ensuring high (Signal-to-Noise Ratio) SNR for the proposed SDM. Meanwhile, other key modules are designed to meet basic requirements and achieve low power consumption at the same time. The proposed SDM was implemented in the SMIC 0.18 μm CMOS technology and its final area is 3.09 mm2. When the sampling frequency of 512KHz and signal bandwidth of 2KHz are adopted, the measured results show that the proposed fourth-order SDM can achieve SNR of 101 dB and ENOB of 16.4 bits with less than 5mW power consumption, which meet the requirements of high dynamic range and low power in MEMS digital geophones. [ABSTRACT FROM AUTHOR]

For the current situation of the large error in civil satellite positioning data resulting in the calculation of smaller mileage by the polyline method than the actual mileage, a new method of mileage statistics has been proposed in this article. First, the original trajectory data are preprocessed to eliminate data errors. Second, based on the principle of shape approximation, it is preferred to implement the quadratic B-spline curve to accurately fit the mileage trajectory curve, comparing various curve fitting methods. Then, based on the trajectory curve control point data, the mileage statistics formula is derived, and the accurate mileage statistics method for non-precision satellite positioning signals is realized. Finally, the road test is carried out by using the photoelectric non-contact five-wheel instrument and GPS equipment. The polyline method and curve fitting method are used to generate contrastive curve and calculate the mileage, respectively. Taking photoelectric five-wheel data as the accurate mileage, the error analysis is carried out. The results show that the deviation between calculated and actual mileage values is less than 1%. Therefore, this method can meet the user's requirements for fleet management. [ABSTRACT FROM AUTHOR]

Phagocytosis of SiO2 into the lung causes an inflammatory cascade that results in fibroblast proliferation and migration, followed by fibrosis. Clinical evidence has indicated that the activation of alveolar macrophages by SiO2 produces rapid and sustained inflammation characterized by the generation of monocyte chemotactic protein 1, which, in turn, induces fibrosis. However, the details of events downstream of monocyte chemotactic protein 1 activity in pulmonary fibroblasts remain unclear. Here, to elucidate the role of p53 in fibrosis induced by silica, both the upstream molecular mechanisms and the functional effects on cell proliferation and migration were investigated. Experiments using primary cultured adult human pulmonary fibroblasts led to the following results: 1) SiO2 treatment resulted in a rapid and sustained increase in p53 and PUMA protein levels; 2) the MAPK and PI3K pathways were involved in the SiO2-induced alteration of p53 and PUMA expression; and 3) RNA interference targeting p53 and PUMA prevented the SiO2-induced increases in fibroblast activation and migration. Our study elucidated a link between SiO2-induced p53/PUMA expression in fibroblasts and cell migration, thereby providing novel insight into the potential use of p53/PUMA in the development of novel therapeutic strategies for silicosis treatment. [ABSTRACT FROM AUTHOR]