Loneliness is classically defined as a result of perceiving a discrepancy between the desired quantity and quality of one's social life and actual social relationships(Perlman and Peplau,1984).Lifespan research ha...Loneliness is classically defined as a result of perceiving a discrepancy between the desired quantity and quality of one's social life and actual social relationships(Perlman and Peplau,1984).Lifespan research has indicated older adults are among the highest risk for experiencing loneliness because their social network size decreases more frequently than that of younger adults.展开更多
Animal models have been extensively used in cancer pathology studies and drug discovery.These models,however,fail to reflect the complex human tumor microenvironment and do not allow for high-throughput drug screening...Animal models have been extensively used in cancer pathology studies and drug discovery.These models,however,fail to reflect the complex human tumor microenvironment and do not allow for high-throughput drug screening in more human-like physiological conditions.Three-dimensional(3D)cancer models present an alternative to automated high-throughput cancer drug discovery and oncology.In this review,we highlight recent technology innovations in building 3D tumor models that simulate the complex human tumor microenvironment and responses of patients to treatment.We discussed various biofabrication technologies,including 3D bioprinting techniques developed for characterizing tumor progression,metastasis,and response to treatment.展开更多
The electronics packaging community strongly believes that Moore’s law will continue for another few years due to recent technological efforts to build heterogeneously integrated packages.Heterogeneous integration(HI...The electronics packaging community strongly believes that Moore’s law will continue for another few years due to recent technological efforts to build heterogeneously integrated packages.Heterogeneous integration(HI)can be at the chip level(a single chip with multiple hotspots),in multi-chip modules,or in vertically stacked three-dimensional(3D)integrated circuits.Flux values have increased exponentially with a simultaneous reduction in chip size and a significant increase in performance,leading to increased heat dissipation.The electronics industry and the academic research community have examined various solutions to tackle skyrocketing thermal-management challenges.Embedded cooling eliminates most sequential conduction resistance from the chip to the ambient,unlike separable cold plates/heat sinks.Although embedding the cooling solution onto an electronic chip results in a high heat transfer potential,technological risks and complexity are still associated with the implementation of these technologies and with uncertainty regarding which technologies will be adopted.This manuscript discusses recent advances in embedded cooling,fluid selection considerations,and conventional,immersion,and additive manufacturing-based embedded cooling technologies.展开更多
The multi-purpose forensics is an important tool for forge image detection.In this paper,we propose a universal feature set for the multi-purpose forensics which is capable of simultaneously identifying several typica...The multi-purpose forensics is an important tool for forge image detection.In this paper,we propose a universal feature set for the multi-purpose forensics which is capable of simultaneously identifying several typical image manipulations,including spatial low-pass Gaussian blurring,median filtering,re-sampling,and JPEG compression.To eliminate the influences caused by diverse image contents on the effectiveness and robustness of the feature,a residual group which contains several high-pass filtered residuals is introduced.The partial correlation coefficient is exploited from the residual group to purely measure neighborhood correlations in a linear way.Besides that,we also combine autoregressive coefficient and transition probability to form the proposed composite feature which is used to measure how manipulations change the neighborhood relationships in both linear and non-linear way.After a series of dimension reductions,the proposed feature set can accelerate the training and testing for the multi-purpose forensics.The proposed feature set is then fed into a multi-classifier to train a multi-purpose detector.Experimental results show that the proposed detector can identify several typical image manipulations,and is superior to the complicated deep CNN-based methods in terms of detection accuracy and time efficiency for JPEG compressed image with low resolution.展开更多
BACKGROUND Hereditary hemochromatosis(HH)has an increased risk of hepatocellular cancer(HCC)both due to genetic risks and iron overload as iron overload can be carcinogenic;HH impacts the increasing risk of HCC,not on...BACKGROUND Hereditary hemochromatosis(HH)has an increased risk of hepatocellular cancer(HCC)both due to genetic risks and iron overload as iron overload can be carcinogenic;HH impacts the increasing risk of HCC,not only through the development of cirrhosis but concerning hepatic iron deposition,which has been studied further recently.AIM To evaluate HH yearly trends,patient demographics,symptoms,comorbidities,and hospital outcomes.The secondary aim sheds light on the risk of iron overload for developing HCC in HH patients,independent of liver cirrhosis complications.The study investigated HH(without cirrhosis)as an independent risk factor for HCC.METHODS We analyzed data from National Inpatient Sample(NIS)Database,the largest national inpatient data collection in the United States,and selected HH and HCC cohorts.HH was first defined in 2011 International Classification of Disease-9th edition(ICD-9)as a separate diagnosis;the HH cohort is extracted from January 2011 to December 2019 using 275.01(ICD-9)and E83.110(ICD-10)diagnosis codes of HH.Patients were excluded from the HH cohort if they had a primary or secondary diagnostic code of cirrhosis(alcoholic,non-alcoholic,and biliary),viralhepatitis,alcoholic liver disease,non-alcoholic fatty liver disease(NAFLD),and non-alcoholic steatohepatitis(NASH).We removed these patients from the HH cohort to rule out bias or ICD-10 diagnostic errors.The HCC cohort is selected from January 2011 to December 2019 using the ICD-9 and ICD-10 codes of HCC.We selected a non-HCC cohort with the 1:1 fixed ratio nearest neighbor(greedy)propensity score method using the patients'age,gender,and race.We performed multivariate analysis for the risk factors of HCC in the HCC and non-HCC matched cohort.We further analyzed HH without cirrhosis(removing HH patients with a diagnosis of cirrhosis)as an independent risk factor of HCC after adjusting all known risk factors of HCC in the multivariate model.RESULTS During the 2011-2019 period,a total of 18031 hospitalizations with a primary or secondary diagnosis of HH(excluding liver diseases)were recorded in the NIS database.We analyzed different patients’characteristics,and we found increments in inpatient population trend with a Ptrend<0.001 and total hospital cost of care trend from$42957 in 2011 to$66152 in 2019 with a Ptrend<0.001 despite no change in Length of Stay over the last decade.The multivariate analyses showed that HH without cirrhosis(aOR,28.8;95%CI,10.4–80.1;P<0.0001),biliary cirrhosis(aOR,19.3;95%CI,13.4–27.6;P<0.0001),non-alcoholic cirrhosis(aOR,17.4;95%CI,16.5–18.4;P<0.0001),alcoholic cirrhosis(aOR,16.9;95%CI,15.9–17.9;P<0.0001),hepatitis B(aOR,12.1;95%CI,10.85–13.60;P<0.0001),hepatitis C(aOR,8.58;95%CI,8.20–8.98;P<0.0001),Wilson disease(aOR,4.27;95%CI,1.18–15.41;P<0.0001),NAFLD or NASH(aOR,2.96;95%CI,2.73–3.20;P<0.0001),alpha1-antitrypsin deficiency(aOR,2.10;95%CI,1.21–3.64;P<0.0001),diabetes mellitus without chronic complications(aOR,1.17;95%CI,1.13–1.21;P<0.0001),and blood transfusion(aOR,1.80;95%CI,1.69–1.92;P<0.0001)are independent risk factor for liver cancer.CONCLUSION Our study showed an increasing trend of in-hospital admissions of HH patients in the last decade.These trends were likely related to advances in diagnostic approach,which can lead to increased hospital utilization and cost increments.Still,the length of stay remained the same,likely due to a big part of management being done in outpatient settings.Another vital part of our study is the significant result that HH without cirrhosis is an independent risk factor for HCC with adjusting all known risk factors.More prospective and retrospective large studies are needed to re-evaluate the HH independent risk in developing HCC.展开更多
4-Aminobutyrate accumulates in plants under abiotic stress.Here,targeted quantitative profiling of metabolites and transcripts was conducted to monitor glutamate-and polyamine-derived 4-aminobutyrate production and it...4-Aminobutyrate accumulates in plants under abiotic stress.Here,targeted quantitative profiling of metabolites and transcripts was conducted to monitor glutamate-and polyamine-derived 4-aminobutyrate production and its subsequent catabolism to succinate or 4-hydroxybutyrate in apple(Malus x domestica Borkh.)fruit stored at 0°C with 2.5 kPa O2 and 0.03 or 5 kPa CO2 for 16 weeks.Low-temperature-induced protein hydrolysis appeared to be responsible for the enhanced availability of amino acids during early storage,and the resulting higher glutamate level stimulated 4-aminobutyrate levels more than polyamines.Elevated CO2 increased the levels of polyamines,as well as succinate and 4-hydroxybutyrate,during early storage,and 4-aminobutyrate and 4-hydroxybutyrate over the longer term.Expression of all of the genes likely involved in 4-aminobutyrate metabolism from glutamate/polyamines to succinate/4-hydroxybutyrate was induced in a co-ordinated manner.CO2-regulated expression of apple GLUTAMATE DECARBOXYLASE 2,AMINE OXIDASE 1,ALDEHYDE DEHYDROGENASE 10A8 and POLYAMINE OXIDASE 2 was evident with longer term storage.Evidence suggested that respiratory activities were restricted by the elevated CO2/O2 environment,and that decreasing NAD+availability and increasing NADPH and NADPH/NADP+,respectively,played key roles in the regulation of succinate and 4-hydroxybutyate accumulation.Together,these findings suggest that both transcriptional and biochemical mechanisms are associated with 4-aminobutyrate and 4-hydroxybutyrate metabolism in apple fruit stored under multiple abiotic stresses.展开更多
In this study, AA2519 alloy was initially processed by multi axial forging (MAF) at room and cryogenic temperatures. Subsequently, the microstructure and the mechanical behavior of the processed samples under quasi-st...In this study, AA2519 alloy was initially processed by multi axial forging (MAF) at room and cryogenic temperatures. Subsequently, the microstructure and the mechanical behavior of the processed samples under quasi-static loading were investigated to determine the influence of cryogenic forging on alloys’ subgrains dimensions, grain boundaries interactions, strength, ductility and toughness. In addition, the failure mechanisms at the tensile rupture surfaces were characterized using scanning electron micro-scope (SEM). The results show significant improvements in the strength, ductility and toughness of the alloy as a result of the cryogenic MAF process. The formation of nanoscale crystallite microstructure, heavily deformed grains with high density of grain boundaries and second phase breakage to finer particles were characterized as the main reasons for the increase in the mechanical properties of the cryogenic forged samples. The cryogenic processing of the alloy resulted in the formation of an ultrafine grained material with tensile strength and toughness that are ~41% and ~80% higher respectively after 2 cycles MAF when compared with the materials processed at ambient temperature. The fractography analysis on the tested materials shows a substantial ductility improvement in the cryoforged (CF) samples when compared to the room temperature forged (RTF) samples which is in alignment with their stress-strain profiles. However, extended forging at higher cycles than 2 cycles led only to increase in strength at the expense of ductility for both the CF and RTF samples.展开更多
Using ab initio molecular dynamics(AIMD)simulations,classical molecular dynamics(CMD)simulations,small-angle X-ray scattering(SAXS),and pulsed-field gradient nuclear magnetic resonance(PFG-NMR),the solvation structure...Using ab initio molecular dynamics(AIMD)simulations,classical molecular dynamics(CMD)simulations,small-angle X-ray scattering(SAXS),and pulsed-field gradient nuclear magnetic resonance(PFG-NMR),the solvation structure and ion dynamics of magnesium bis(trifluoromethanesulfonyl)imide(Mg(TFSI)_(2))aqueous electrolyte at 1,2,and 3 m concentrations are investigated.From AIMD and CMD simulations,the first solvation shell of an Mg;ion is found to be composed of six water molecules in an octahedral configuration and the solvation shell is rather rigid.The TFSI^(-)ions prefer to stay in the second solvation shell and beyond.Meanwhile,the comparable diffusion coefficients of positive and negative ions in Mg(TFSI)_(2)aqueous electrolytes have been observed,which is mainly due to the formation of the stable[Mg(H_(2)O_(6))_(2)]^(+)complex,and,as a result,the increased effective Mg ion size.Finally,the calculated correlated transference numbers are lower than the uncorrelated ones even at the low concentration of 2 and 3 m,suggesting the enhanced correlations between ions in the multivalent electrolytes.This work provides a molecular-level understanding of how the solvation structure and multivalency of the ion affect the dynamics and transport properties of the multivalent electrolyte,providing insight for rational designs of electrolytes for improved ion transport properties.展开更多
This paper investigates the feedback control of hidden Markov process(HMP) in the face of loss of some observation processes.The control action facilitates or impedes some particular transitions from an inferred cur...This paper investigates the feedback control of hidden Markov process(HMP) in the face of loss of some observation processes.The control action facilitates or impedes some particular transitions from an inferred current state in the attempt to maximize the probability that the HMP is driven to a desirable absorbing state.This control problem is motivated by the need for judicious resource allocation to win an air operation involving two opposing forces.The effectiveness of a receding horizon control scheme based on the inferred discrete state is examined.Tolerance to loss of sensors that help determine the state of the air operation is achieved through a decentralized scheme that estimates a continuous state from measurements of linear models with additive noise.The discrete state of the HMP is identified using three well-known detection schemes.The sub-optimal control policy based on the detected state is implemented on-line in a closed-loop,where the air operation is simulated as a stochastic process with SimEvents,and the measurement process is simulated for a range of single sensor loss rates.展开更多
This paper analyzes fault-tolerance over the entire design life of a class of multiple-hop wireless networks, where cooperative transmission schemes are used. The networks are subject to both node failure and random c...This paper analyzes fault-tolerance over the entire design life of a class of multiple-hop wireless networks, where cooperative transmission schemes are used. The networks are subject to both node failure and random channel fading. A node lifetime distribution is modeled with an increasing failure rate, where the node power consumption level enters the parameters of the distribution. A method for assessing both link and network reliabilities projected at the network's design life is developed. Link reliability is enhanced through use of redundant nodes. The number of redundant nodes is restricted by the cooperative transmission scheme used. The link reliability is then used to establish a re-transmission control policy that minimizes an expected cost involving power, bandwidth expenditures, and packet loss. The benefit and cost of feedback in network operations are examined. The results of a simulation study under specific node processing times are presented. The study quantifies the effect of loop closure frequency, acknowledgment deadline, and nodes' storage capacity on the performance of the network in terms of network lifetime, packet loss rate, and false alarm rate. The study concludes that in a network where energy is severely constrained, feedback must be applied judiciously.展开更多
The thermodynamic properties of the bilayer ruthenate compound Sr3Ru2O7 at very low temperatures are inves- tigated by using a tight-binding model yielding the realistic band structure combined with the on-site intera...The thermodynamic properties of the bilayer ruthenate compound Sr3Ru2O7 at very low temperatures are inves- tigated by using a tight-binding model yielding the realistic band structure combined with the on-site interactions treated at the mean-field level. We find that both the total density of states at the Fermi energy and the entropy exhibit a sudden increase near the critical magnetic field for the nematic phase, echoing the experimental find- ings. A new mechanism to explain the anisotropic transport properties is proposed based on scatterings at the anisotropic domain boundaries. Our results suggest that extra cares are necessary to isolate the contributions due to the quantum criticality from the band structure singularity in Sr3Ru2O7.展开更多
Muscle imbalances are a well accepted cause of musculo-skeletal pain, yet clinicians lack a simple, non-invasive, and reproducible means to assess muscle effort during activities of daily living. To address this issue...Muscle imbalances are a well accepted cause of musculo-skeletal pain, yet clinicians lack a simple, non-invasive, and reproducible means to assess muscle effort during activities of daily living. To address this issue, we have been developing vibromyography (VMG) as a means to quantitatively assess muscle mechanical effort such that accurate muscle effort ratios can be determined in the clinic. In this study, VMG was used to characterize muscle imbalances in older adults with low-level knee pain while they performed step-up and step-down activities. In addition to determining whether VMG can identify the imbalances previously reported in individuals with knee pain, we address the question of whether these knee muscle imbalances were a likely cause of knee pain, or whether the imbalances represented a coping response for pre-existing knee pain. A population (N = 30) of 35 - 85 year old men and women with a total of 42 painful knees were assessed. Robust multiple step-wise regression analysis identified weak hip abductor muscle effort relative to hamstring muscle effort as the best predictor of knee pain (p = 0.00006), with weak vastus lateralis effort in eccentric contraction, relative to concentric contraction, being the second best predictor (p = 0.0003). Muscle imbalances were able to account for 40% of the variation in reported pain, and the observed pattern of increasing knee pain with increasing quadriceps strength during concentric contraction leads us to infer that the observed muscle imbalances are not the result of a protective action by the individual, but rather are a principle cause of the knee pain.展开更多
Nanocomposites were fabricated by using a commercial two part epoxy as a matrix and multiwalled carbon nanotubes, graphite fibers and boron nitride platelets as filler materials. Multiwalled carbon nanotubes (MWCNTs) ...Nanocomposites were fabricated by using a commercial two part epoxy as a matrix and multiwalled carbon nanotubes, graphite fibers and boron nitride platelets as filler materials. Multiwalled carbon nanotubes (MWCNTs) that were produced by chemical vapor deposition were found to produce nanocomposites with better thermal diffusivity and thermal conductivity than the MWCNTs that were produced by the combustion method. Compared to the MWCNTs produced by both methods and graphite fibers, boron nitride produced nanocomposites with the highest thermal conductivity. Specific heat capacity was measured by using differential scanning calorimetry and thermal diffusivity was measured by using the laser flash.展开更多
In recent years, aluminum-matrix composites (AMCs) have been widely used to replace cast iron in aerospace and automotive industries. Machining of these composite materials requires better understanding of cutting pro...In recent years, aluminum-matrix composites (AMCs) have been widely used to replace cast iron in aerospace and automotive industries. Machining of these composite materials requires better understanding of cutting processes re- garding accuracy and efficiency. This study addresses the modeling of the machinability of self-lubricated aluminum /alumina/graphite hybrid composites synthesized by the powder metallurgy method. In this study, multiple regression analysis (MRA) and artificial neural networks (ANN) were used to investigate the influence of some parameters on the thrust force and torque in the drilling processes of self-lubricated hybrid composite materials. The models were identi- fied by using cutting speed, feed, and volume fraction of the reinforcement particles as input data and the thrust force and torque as the output data. A comparison between two prediction methods was developed to compare the prediction accuracy. ANNs showed better predictability results compared to MRA due to the nonlinearity nature of ANNs. The statistical analysis accompanied with artificial neural network results showed that Al2O3, Gr and cutting feed (f) were the most significant parameters on the drilling process, while spindle speed seemed insignificant. Since the spindle speed was insignificant, it directed us to set it either at the highest spindle speed to obtain high material removal rate or at the lowest spindle speed to prolong the tool life depending on the need for the application.展开更多
Diastasis Recti Abdominis(DRA)is the separation of abdominal recti muscles which occurs in women during their pregnancy and postpartum time.This is because of the stretching of the linea alba,a fibrous connective tiss...Diastasis Recti Abdominis(DRA)is the separation of abdominal recti muscles which occurs in women during their pregnancy and postpartum time.This is because of the stretching of the linea alba,a fibrous connective tissue on the abdominal wall.The Linea Alba is elastic and retracts back after the delivery of the baby.When this tissue gets overstretched,it loses its elasticity and the gap in the abdominals may not be closed leading to DRA.The motive of this research is to analyze the postpartum rehabilitation for signals from Inertial Measurement Unit(IMU)sensors.The conservative treatment for women who are experiencing DRA is given in the form of physiotherapy.These physiotherapy exercises focus on the recti abdominis muscle to bring back the Linea alba together.It will be a difficult process for the physiotherapist to monitor,whether patients did the exercises correctly or not.If the exercises are not correct,they will not be effective in the reduction of inter-recti distance.This research aims to analyze the effectiveness of IMU signals in classifying the correct and incorrect exercises.It was inferred that the IMU signals are effective in classifying the correct and incorrect exercises with an accuracy of 92%.展开更多
Electroceuticals are medical devices that employ electric signals to alter the activity of specific nerve fibers to achieve therapeutic effects. The rapid growth of RF microelectronics has resulted in the development ...Electroceuticals are medical devices that employ electric signals to alter the activity of specific nerve fibers to achieve therapeutic effects. The rapid growth of RF microelectronics has resulted in the development of very small, portable, and inexpensive shortwave and microwave radio frequency (RF) amplifiers, raising the possibility of utilizing these new RF technologies to develop non-contact electroceutical devices. However, the bio-electromagnetics literature suggests that beyond 10 MHz, RF fields cannot influence biological tissue, beyond simple heating, because effective demodulation mechanisms at these frequencies do not exist in the body. However, RF amplifiers operating at or near saturation have non-linear interactions with complex loads, and if body tissue creates a complex loading condition, the opportunity exists for the coupled system to produce non-linear effects, that is, the equivalent of demodulation may occur. Correspondingly, exposure of tissue to pulsed RF energy could result in the creation of low frequency demodulation components capable of influencing tissue activity. Here, we develop a one-dimen- sional, numerical simulation to investigate the complex loading conditions under which such demodulation could arise. Applying these results in a physical prototype device, we show that up to7.5% demodulation can be obtained for a 40 MHz RF field pulsed at 1 KHz. Implications for this research include the possibility of developing wearable, electromagnetic electroceutical de- vices.展开更多
Aligned polyaniline nanorods were synthesized in the presence of salicylic acid. Nanorods and nanotubes were also formed in the presence of camphorsulfonic acid (CSA) and para-toluenesulfonic acid (pTSA). Electrical c...Aligned polyaniline nanorods were synthesized in the presence of salicylic acid. Nanorods and nanotubes were also formed in the presence of camphorsulfonic acid (CSA) and para-toluenesulfonic acid (pTSA). Electrical conductivity measurements showed that the aligned nanorods had better electrical conductivity than the non-aligned nanostructures. Nanospheres were also observed in some cases. The formation of elongated nanostructures or spheres depended on the aniline monomer to surfactant molar ratio. This method in which nanostructures are formed using soft templates is often referred to as the template-free approach. Our success motivated us to explore the feasibility of obtaining similar metallic nanostructures without the use of a template. We successfully synthesized copper and copper hydroxide nanowires. While the copper nanowires formed as a mesh, the copper hydroxide nanowires formed as winding bundles. Upon switching the order in which the reactants were added, copper hydroxide nanoribbons were formed instead of bundles. Characterization of these nanostructures was done using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR) and the Four-point probe to measure electrical conductivity. Both metallic and organic nanowires that are fabricated by template-free methods are potential candidates for use as fillers in polymer nanocomposites. Polymer nanocomposites are found to be used in many advanced modern applications such as thermal interface materials in electronic devices which continue to be miniaturized, aerospace engineering where lightweight and robustness are important, sensors, medicine and catalytic activity.展开更多
Video steganography plays an important role in secret communication that conceals a secret video in a cover video by perturbing the value of pixels in the cover frames.Imperceptibility is the first and foremost requir...Video steganography plays an important role in secret communication that conceals a secret video in a cover video by perturbing the value of pixels in the cover frames.Imperceptibility is the first and foremost requirement of any steganographic approach.Inspired by the fact that human eyes perceive pixel perturbation differently in different video areas,a novel effective and efficient Deeply‐Recursive Attention Network(DRANet)for video steganography to find suitable areas for information hiding via modelling spatio‐temporal attention is proposed.The DRANet mainly contains two important components,a Non‐Local Self‐Attention(NLSA)block and a Non‐Local Co‐Attention(NLCA)block.Specifically,the NLSA block can select the cover frame areas which are suitable for hiding by computing the correlations among inter‐and intra‐cover frames.The NLCA block aims to effectively produce the enhanced representations of the secret frames to enhance the robustness of the model and alleviate the influence of different areas in the secret video.Furthermore,the DRANet reduces the model parameters by performing similar operations on the different frames within an input video recursively.Experimental results show the proposed DRANet achieves better performance with fewer parameters than the state‐of‐the‐art competitors.展开更多
The electrical properties of magnetic sensing devices fabricated from anisotropic materials are not easily extracted. Here we present a method for determining the resistance matrix for an anisotropic device with multi...The electrical properties of magnetic sensing devices fabricated from anisotropic materials are not easily extracted. Here we present a method for determining the resistance matrix for an anisotropic device with multiple electrical contacts placed in a perpendicular magnetic field. By using the methods developed by Van der Pauw and Wasscher, the analysis for the anisotropic system is reduced to the equivalent problem for an isotropic sample, which can then be solved using methods developed previously. As a result, the method works in the case of structures with an arbitrary number of asymmetric extended contacts at large magnetic field strength. In addition to the extraction of nonisotropic resistivities, the resistance matrix can be used to analyze the Hall effect for anisotropic plates.展开更多
Nickel-rich transition-metal oxides are widely regarded as promising cathode materials for high-energydensity lithium-ion batteries for emerging electric vehicles. However, achieving high energy density in Ni-rich cat...Nickel-rich transition-metal oxides are widely regarded as promising cathode materials for high-energydensity lithium-ion batteries for emerging electric vehicles. However, achieving high energy density in Ni-rich cathodes is accompanied by substantial safety and cycle-life obstacles. The major issues of Ni-rich cathodes at high working potentials are originated from the unstable cathode-electrolyte interface, while the underlying mechanism of parasitic reactions towards surface reconstructions of cathode materials is not well understood. In this work, we controlled the Li_(2)CO_(3) impurity content on LiNi_(0.83)Mn_(0.1)Co_(0.07)O_(2) cathodes using air, tank-air, and O_(2) synthesis environments. Home-built high-precision leakage current and on-line electrochemical mass spectroscopy experiments verify that Li_(2)CO_(3) impurity is a significant promoter of parasitic reactions on Ni-rich cathodes. The rate of parasitic reactions is strongly correlated to Li_(2)CO_(3) content and severe performance deterioration of Ni83 cathodes.The post-mortem characterizations via high-resolution transition electron microscope and X-ray photoelectron spectroscopy depth profiles reveal that parasitic reactions promote more Ni reduction and O deficiency and even rock-salt phase transformation at the surface of cathode materials. Our observation suggests that surface reconstructions have a strong affiliation to parasitic reactions that create chemically acidic environment to etch away the lattice oxygen and offer the electrical charge to reduce the valence state of transition metal. Thus, this study advances our understanding on surface reconstructions of Nirich cathodes and prepares us for searching for rational strategies.展开更多
文摘Loneliness is classically defined as a result of perceiving a discrepancy between the desired quantity and quality of one's social life and actual social relationships(Perlman and Peplau,1984).Lifespan research has indicated older adults are among the highest risk for experiencing loneliness because their social network size decreases more frequently than that of younger adults.
文摘Animal models have been extensively used in cancer pathology studies and drug discovery.These models,however,fail to reflect the complex human tumor microenvironment and do not allow for high-throughput drug screening in more human-like physiological conditions.Three-dimensional(3D)cancer models present an alternative to automated high-throughput cancer drug discovery and oncology.In this review,we highlight recent technology innovations in building 3D tumor models that simulate the complex human tumor microenvironment and responses of patients to treatment.We discussed various biofabrication technologies,including 3D bioprinting techniques developed for characterizing tumor progression,metastasis,and response to treatment.
基金supported by National Science Foundation(1941181)National Science Foundation(1846157)+1 种基金Semiconductor Research Corporation CHIRP(Task 2878.006)Department of Defense(13000844-021).
文摘The electronics packaging community strongly believes that Moore’s law will continue for another few years due to recent technological efforts to build heterogeneously integrated packages.Heterogeneous integration(HI)can be at the chip level(a single chip with multiple hotspots),in multi-chip modules,or in vertically stacked three-dimensional(3D)integrated circuits.Flux values have increased exponentially with a simultaneous reduction in chip size and a significant increase in performance,leading to increased heat dissipation.The electronics industry and the academic research community have examined various solutions to tackle skyrocketing thermal-management challenges.Embedded cooling eliminates most sequential conduction resistance from the chip to the ambient,unlike separable cold plates/heat sinks.Although embedding the cooling solution onto an electronic chip results in a high heat transfer potential,technological risks and complexity are still associated with the implementation of these technologies and with uncertainty regarding which technologies will be adopted.This manuscript discusses recent advances in embedded cooling,fluid selection considerations,and conventional,immersion,and additive manufacturing-based embedded cooling technologies.
基金supported by NSFC(No.61702429)Sichuan Science and Technology Program(No.19yyjc1656).
文摘The multi-purpose forensics is an important tool for forge image detection.In this paper,we propose a universal feature set for the multi-purpose forensics which is capable of simultaneously identifying several typical image manipulations,including spatial low-pass Gaussian blurring,median filtering,re-sampling,and JPEG compression.To eliminate the influences caused by diverse image contents on the effectiveness and robustness of the feature,a residual group which contains several high-pass filtered residuals is introduced.The partial correlation coefficient is exploited from the residual group to purely measure neighborhood correlations in a linear way.Besides that,we also combine autoregressive coefficient and transition probability to form the proposed composite feature which is used to measure how manipulations change the neighborhood relationships in both linear and non-linear way.After a series of dimension reductions,the proposed feature set can accelerate the training and testing for the multi-purpose forensics.The proposed feature set is then fed into a multi-classifier to train a multi-purpose detector.Experimental results show that the proposed detector can identify several typical image manipulations,and is superior to the complicated deep CNN-based methods in terms of detection accuracy and time efficiency for JPEG compressed image with low resolution.
文摘BACKGROUND Hereditary hemochromatosis(HH)has an increased risk of hepatocellular cancer(HCC)both due to genetic risks and iron overload as iron overload can be carcinogenic;HH impacts the increasing risk of HCC,not only through the development of cirrhosis but concerning hepatic iron deposition,which has been studied further recently.AIM To evaluate HH yearly trends,patient demographics,symptoms,comorbidities,and hospital outcomes.The secondary aim sheds light on the risk of iron overload for developing HCC in HH patients,independent of liver cirrhosis complications.The study investigated HH(without cirrhosis)as an independent risk factor for HCC.METHODS We analyzed data from National Inpatient Sample(NIS)Database,the largest national inpatient data collection in the United States,and selected HH and HCC cohorts.HH was first defined in 2011 International Classification of Disease-9th edition(ICD-9)as a separate diagnosis;the HH cohort is extracted from January 2011 to December 2019 using 275.01(ICD-9)and E83.110(ICD-10)diagnosis codes of HH.Patients were excluded from the HH cohort if they had a primary or secondary diagnostic code of cirrhosis(alcoholic,non-alcoholic,and biliary),viralhepatitis,alcoholic liver disease,non-alcoholic fatty liver disease(NAFLD),and non-alcoholic steatohepatitis(NASH).We removed these patients from the HH cohort to rule out bias or ICD-10 diagnostic errors.The HCC cohort is selected from January 2011 to December 2019 using the ICD-9 and ICD-10 codes of HCC.We selected a non-HCC cohort with the 1:1 fixed ratio nearest neighbor(greedy)propensity score method using the patients'age,gender,and race.We performed multivariate analysis for the risk factors of HCC in the HCC and non-HCC matched cohort.We further analyzed HH without cirrhosis(removing HH patients with a diagnosis of cirrhosis)as an independent risk factor of HCC after adjusting all known risk factors of HCC in the multivariate model.RESULTS During the 2011-2019 period,a total of 18031 hospitalizations with a primary or secondary diagnosis of HH(excluding liver diseases)were recorded in the NIS database.We analyzed different patients’characteristics,and we found increments in inpatient population trend with a Ptrend<0.001 and total hospital cost of care trend from$42957 in 2011 to$66152 in 2019 with a Ptrend<0.001 despite no change in Length of Stay over the last decade.The multivariate analyses showed that HH without cirrhosis(aOR,28.8;95%CI,10.4–80.1;P<0.0001),biliary cirrhosis(aOR,19.3;95%CI,13.4–27.6;P<0.0001),non-alcoholic cirrhosis(aOR,17.4;95%CI,16.5–18.4;P<0.0001),alcoholic cirrhosis(aOR,16.9;95%CI,15.9–17.9;P<0.0001),hepatitis B(aOR,12.1;95%CI,10.85–13.60;P<0.0001),hepatitis C(aOR,8.58;95%CI,8.20–8.98;P<0.0001),Wilson disease(aOR,4.27;95%CI,1.18–15.41;P<0.0001),NAFLD or NASH(aOR,2.96;95%CI,2.73–3.20;P<0.0001),alpha1-antitrypsin deficiency(aOR,2.10;95%CI,1.21–3.64;P<0.0001),diabetes mellitus without chronic complications(aOR,1.17;95%CI,1.13–1.21;P<0.0001),and blood transfusion(aOR,1.80;95%CI,1.69–1.92;P<0.0001)are independent risk factor for liver cancer.CONCLUSION Our study showed an increasing trend of in-hospital admissions of HH patients in the last decade.These trends were likely related to advances in diagnostic approach,which can lead to increased hospital utilization and cost increments.Still,the length of stay remained the same,likely due to a big part of management being done in outpatient settings.Another vital part of our study is the significant result that HH without cirrhosis is an independent risk factor for HCC with adjusting all known risk factors.More prospective and retrospective large studies are needed to re-evaluate the HH independent risk in developing HCC.
基金The research was supported by funding from the Natural Sciences and Engineering Research Council(NSERC)of Canada as Strategic Project(B.J.S.and G.G.B.),Collaborative Research and Development(G.G.B.,B.J.S.and J.R.D.)and Individual Discovery(B.J.S.)Grants,and from the Ontario Ministry of Agriculture,Food&Rural Affairs,Rohm&Haas Canada LP(AgroFresh Inc.B.J.S.,G.G.B.and J.R.D.),and the Ontario Apple Growers(B.J.S.,G.G.B.and J.R.D.).
文摘4-Aminobutyrate accumulates in plants under abiotic stress.Here,targeted quantitative profiling of metabolites and transcripts was conducted to monitor glutamate-and polyamine-derived 4-aminobutyrate production and its subsequent catabolism to succinate or 4-hydroxybutyrate in apple(Malus x domestica Borkh.)fruit stored at 0°C with 2.5 kPa O2 and 0.03 or 5 kPa CO2 for 16 weeks.Low-temperature-induced protein hydrolysis appeared to be responsible for the enhanced availability of amino acids during early storage,and the resulting higher glutamate level stimulated 4-aminobutyrate levels more than polyamines.Elevated CO2 increased the levels of polyamines,as well as succinate and 4-hydroxybutyrate,during early storage,and 4-aminobutyrate and 4-hydroxybutyrate over the longer term.Expression of all of the genes likely involved in 4-aminobutyrate metabolism from glutamate/polyamines to succinate/4-hydroxybutyrate was induced in a co-ordinated manner.CO2-regulated expression of apple GLUTAMATE DECARBOXYLASE 2,AMINE OXIDASE 1,ALDEHYDE DEHYDROGENASE 10A8 and POLYAMINE OXIDASE 2 was evident with longer term storage.Evidence suggested that respiratory activities were restricted by the elevated CO2/O2 environment,and that decreasing NAD+availability and increasing NADPH and NADPH/NADP+,respectively,played key roles in the regulation of succinate and 4-hydroxybutyate accumulation.Together,these findings suggest that both transcriptional and biochemical mechanisms are associated with 4-aminobutyrate and 4-hydroxybutyrate metabolism in apple fruit stored under multiple abiotic stresses.
文摘In this study, AA2519 alloy was initially processed by multi axial forging (MAF) at room and cryogenic temperatures. Subsequently, the microstructure and the mechanical behavior of the processed samples under quasi-static loading were investigated to determine the influence of cryogenic forging on alloys’ subgrains dimensions, grain boundaries interactions, strength, ductility and toughness. In addition, the failure mechanisms at the tensile rupture surfaces were characterized using scanning electron micro-scope (SEM). The results show significant improvements in the strength, ductility and toughness of the alloy as a result of the cryogenic MAF process. The formation of nanoscale crystallite microstructure, heavily deformed grains with high density of grain boundaries and second phase breakage to finer particles were characterized as the main reasons for the increase in the mechanical properties of the cryogenic forged samples. The cryogenic processing of the alloy resulted in the formation of an ultrafine grained material with tensile strength and toughness that are ~41% and ~80% higher respectively after 2 cycles MAF when compared with the materials processed at ambient temperature. The fractography analysis on the tested materials shows a substantial ductility improvement in the cryoforged (CF) samples when compared to the room temperature forged (RTF) samples which is in alignment with their stress-strain profiles. However, extended forging at higher cycles than 2 cycles led only to increase in strength at the expense of ductility for both the CF and RTF samples.
基金supported by the Joint Center for Energy Storage Research(JCESR),a U.S.Department of Energy,Energy Innovation Hub。
文摘Using ab initio molecular dynamics(AIMD)simulations,classical molecular dynamics(CMD)simulations,small-angle X-ray scattering(SAXS),and pulsed-field gradient nuclear magnetic resonance(PFG-NMR),the solvation structure and ion dynamics of magnesium bis(trifluoromethanesulfonyl)imide(Mg(TFSI)_(2))aqueous electrolyte at 1,2,and 3 m concentrations are investigated.From AIMD and CMD simulations,the first solvation shell of an Mg;ion is found to be composed of six water molecules in an octahedral configuration and the solvation shell is rather rigid.The TFSI^(-)ions prefer to stay in the second solvation shell and beyond.Meanwhile,the comparable diffusion coefficients of positive and negative ions in Mg(TFSI)_(2)aqueous electrolytes have been observed,which is mainly due to the formation of the stable[Mg(H_(2)O_(6))_(2)]^(+)complex,and,as a result,the increased effective Mg ion size.Finally,the calculated correlated transference numbers are lower than the uncorrelated ones even at the low concentration of 2 and 3 m,suggesting the enhanced correlations between ions in the multivalent electrolytes.This work provides a molecular-level understanding of how the solvation structure and multivalency of the ion affect the dynamics and transport properties of the multivalent electrolyte,providing insight for rational designs of electrolytes for improved ion transport properties.
文摘This paper investigates the feedback control of hidden Markov process(HMP) in the face of loss of some observation processes.The control action facilitates or impedes some particular transitions from an inferred current state in the attempt to maximize the probability that the HMP is driven to a desirable absorbing state.This control problem is motivated by the need for judicious resource allocation to win an air operation involving two opposing forces.The effectiveness of a receding horizon control scheme based on the inferred discrete state is examined.Tolerance to loss of sensors that help determine the state of the air operation is achieved through a decentralized scheme that estimates a continuous state from measurements of linear models with additive noise.The discrete state of the HMP is identified using three well-known detection schemes.The sub-optimal control policy based on the detected state is implemented on-line in a closed-loop,where the air operation is simulated as a stochastic process with SimEvents,and the measurement process is simulated for a range of single sensor loss rates.
基金This work was partly supported by the US AFOSR (No. FA9550-06-0456 and FA9550-06-10249).
文摘This paper analyzes fault-tolerance over the entire design life of a class of multiple-hop wireless networks, where cooperative transmission schemes are used. The networks are subject to both node failure and random channel fading. A node lifetime distribution is modeled with an increasing failure rate, where the node power consumption level enters the parameters of the distribution. A method for assessing both link and network reliabilities projected at the network's design life is developed. Link reliability is enhanced through use of redundant nodes. The number of redundant nodes is restricted by the cooperative transmission scheme used. The link reliability is then used to establish a re-transmission control policy that minimizes an expected cost involving power, bandwidth expenditures, and packet loss. The benefit and cost of feedback in network operations are examined. The results of a simulation study under specific node processing times are presented. The study quantifies the effect of loop closure frequency, acknowledgment deadline, and nodes' storage capacity on the performance of the network in terms of network lifetime, packet loss rate, and false alarm rate. The study concludes that in a network where energy is severely constrained, feedback must be applied judiciously.
基金Supported by the NSF DMR-1410375 and AFOSR FA9550-14-1-0168the President's Research Catalyst Award(No CA-15-327861) from the University of California Office of the Presidentthe CAS/SAFEA International Partnership Program for Creative Research Teams
文摘The thermodynamic properties of the bilayer ruthenate compound Sr3Ru2O7 at very low temperatures are inves- tigated by using a tight-binding model yielding the realistic band structure combined with the on-site interactions treated at the mean-field level. We find that both the total density of states at the Fermi energy and the entropy exhibit a sudden increase near the critical magnetic field for the nematic phase, echoing the experimental find- ings. A new mechanism to explain the anisotropic transport properties is proposed based on scatterings at the anisotropic domain boundaries. Our results suggest that extra cares are necessary to isolate the contributions due to the quantum criticality from the band structure singularity in Sr3Ru2O7.
文摘Muscle imbalances are a well accepted cause of musculo-skeletal pain, yet clinicians lack a simple, non-invasive, and reproducible means to assess muscle effort during activities of daily living. To address this issue, we have been developing vibromyography (VMG) as a means to quantitatively assess muscle mechanical effort such that accurate muscle effort ratios can be determined in the clinic. In this study, VMG was used to characterize muscle imbalances in older adults with low-level knee pain while they performed step-up and step-down activities. In addition to determining whether VMG can identify the imbalances previously reported in individuals with knee pain, we address the question of whether these knee muscle imbalances were a likely cause of knee pain, or whether the imbalances represented a coping response for pre-existing knee pain. A population (N = 30) of 35 - 85 year old men and women with a total of 42 painful knees were assessed. Robust multiple step-wise regression analysis identified weak hip abductor muscle effort relative to hamstring muscle effort as the best predictor of knee pain (p = 0.00006), with weak vastus lateralis effort in eccentric contraction, relative to concentric contraction, being the second best predictor (p = 0.0003). Muscle imbalances were able to account for 40% of the variation in reported pain, and the observed pattern of increasing knee pain with increasing quadriceps strength during concentric contraction leads us to infer that the observed muscle imbalances are not the result of a protective action by the individual, but rather are a principle cause of the knee pain.
文摘Nanocomposites were fabricated by using a commercial two part epoxy as a matrix and multiwalled carbon nanotubes, graphite fibers and boron nitride platelets as filler materials. Multiwalled carbon nanotubes (MWCNTs) that were produced by chemical vapor deposition were found to produce nanocomposites with better thermal diffusivity and thermal conductivity than the MWCNTs that were produced by the combustion method. Compared to the MWCNTs produced by both methods and graphite fibers, boron nitride produced nanocomposites with the highest thermal conductivity. Specific heat capacity was measured by using differential scanning calorimetry and thermal diffusivity was measured by using the laser flash.
文摘In recent years, aluminum-matrix composites (AMCs) have been widely used to replace cast iron in aerospace and automotive industries. Machining of these composite materials requires better understanding of cutting processes re- garding accuracy and efficiency. This study addresses the modeling of the machinability of self-lubricated aluminum /alumina/graphite hybrid composites synthesized by the powder metallurgy method. In this study, multiple regression analysis (MRA) and artificial neural networks (ANN) were used to investigate the influence of some parameters on the thrust force and torque in the drilling processes of self-lubricated hybrid composite materials. The models were identi- fied by using cutting speed, feed, and volume fraction of the reinforcement particles as input data and the thrust force and torque as the output data. A comparison between two prediction methods was developed to compare the prediction accuracy. ANNs showed better predictability results compared to MRA due to the nonlinearity nature of ANNs. The statistical analysis accompanied with artificial neural network results showed that Al2O3, Gr and cutting feed (f) were the most significant parameters on the drilling process, while spindle speed seemed insignificant. Since the spindle speed was insignificant, it directed us to set it either at the highest spindle speed to obtain high material removal rate or at the lowest spindle speed to prolong the tool life depending on the need for the application.
基金This research was funded by the Department of Science and Technology DST under Biomedical Device and Technology Development(File No:TDP/BDTD/07/2021).
文摘Diastasis Recti Abdominis(DRA)is the separation of abdominal recti muscles which occurs in women during their pregnancy and postpartum time.This is because of the stretching of the linea alba,a fibrous connective tissue on the abdominal wall.The Linea Alba is elastic and retracts back after the delivery of the baby.When this tissue gets overstretched,it loses its elasticity and the gap in the abdominals may not be closed leading to DRA.The motive of this research is to analyze the postpartum rehabilitation for signals from Inertial Measurement Unit(IMU)sensors.The conservative treatment for women who are experiencing DRA is given in the form of physiotherapy.These physiotherapy exercises focus on the recti abdominis muscle to bring back the Linea alba together.It will be a difficult process for the physiotherapist to monitor,whether patients did the exercises correctly or not.If the exercises are not correct,they will not be effective in the reduction of inter-recti distance.This research aims to analyze the effectiveness of IMU signals in classifying the correct and incorrect exercises.It was inferred that the IMU signals are effective in classifying the correct and incorrect exercises with an accuracy of 92%.
文摘Electroceuticals are medical devices that employ electric signals to alter the activity of specific nerve fibers to achieve therapeutic effects. The rapid growth of RF microelectronics has resulted in the development of very small, portable, and inexpensive shortwave and microwave radio frequency (RF) amplifiers, raising the possibility of utilizing these new RF technologies to develop non-contact electroceutical devices. However, the bio-electromagnetics literature suggests that beyond 10 MHz, RF fields cannot influence biological tissue, beyond simple heating, because effective demodulation mechanisms at these frequencies do not exist in the body. However, RF amplifiers operating at or near saturation have non-linear interactions with complex loads, and if body tissue creates a complex loading condition, the opportunity exists for the coupled system to produce non-linear effects, that is, the equivalent of demodulation may occur. Correspondingly, exposure of tissue to pulsed RF energy could result in the creation of low frequency demodulation components capable of influencing tissue activity. Here, we develop a one-dimen- sional, numerical simulation to investigate the complex loading conditions under which such demodulation could arise. Applying these results in a physical prototype device, we show that up to7.5% demodulation can be obtained for a 40 MHz RF field pulsed at 1 KHz. Implications for this research include the possibility of developing wearable, electromagnetic electroceutical de- vices.
文摘Aligned polyaniline nanorods were synthesized in the presence of salicylic acid. Nanorods and nanotubes were also formed in the presence of camphorsulfonic acid (CSA) and para-toluenesulfonic acid (pTSA). Electrical conductivity measurements showed that the aligned nanorods had better electrical conductivity than the non-aligned nanostructures. Nanospheres were also observed in some cases. The formation of elongated nanostructures or spheres depended on the aniline monomer to surfactant molar ratio. This method in which nanostructures are formed using soft templates is often referred to as the template-free approach. Our success motivated us to explore the feasibility of obtaining similar metallic nanostructures without the use of a template. We successfully synthesized copper and copper hydroxide nanowires. While the copper nanowires formed as a mesh, the copper hydroxide nanowires formed as winding bundles. Upon switching the order in which the reactants were added, copper hydroxide nanoribbons were formed instead of bundles. Characterization of these nanostructures was done using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR) and the Four-point probe to measure electrical conductivity. Both metallic and organic nanowires that are fabricated by template-free methods are potential candidates for use as fillers in polymer nanocomposites. Polymer nanocomposites are found to be used in many advanced modern applications such as thermal interface materials in electronic devices which continue to be miniaturized, aerospace engineering where lightweight and robustness are important, sensors, medicine and catalytic activity.
基金supported in part by NSFC(62002320,U19B2043,61672456)the Key R&D Program of Zhejiang Province,China(2021C01119).
文摘Video steganography plays an important role in secret communication that conceals a secret video in a cover video by perturbing the value of pixels in the cover frames.Imperceptibility is the first and foremost requirement of any steganographic approach.Inspired by the fact that human eyes perceive pixel perturbation differently in different video areas,a novel effective and efficient Deeply‐Recursive Attention Network(DRANet)for video steganography to find suitable areas for information hiding via modelling spatio‐temporal attention is proposed.The DRANet mainly contains two important components,a Non‐Local Self‐Attention(NLSA)block and a Non‐Local Co‐Attention(NLCA)block.Specifically,the NLSA block can select the cover frame areas which are suitable for hiding by computing the correlations among inter‐and intra‐cover frames.The NLCA block aims to effectively produce the enhanced representations of the secret frames to enhance the robustness of the model and alleviate the influence of different areas in the secret video.Furthermore,the DRANet reduces the model parameters by performing similar operations on the different frames within an input video recursively.Experimental results show the proposed DRANet achieves better performance with fewer parameters than the state‐of‐the‐art competitors.
文摘The electrical properties of magnetic sensing devices fabricated from anisotropic materials are not easily extracted. Here we present a method for determining the resistance matrix for an anisotropic device with multiple electrical contacts placed in a perpendicular magnetic field. By using the methods developed by Van der Pauw and Wasscher, the analysis for the anisotropic system is reduced to the equivalent problem for an isotropic sample, which can then be solved using methods developed previously. As a result, the method works in the case of structures with an arbitrary number of asymmetric extended contacts at large magnetic field strength. In addition to the extraction of nonisotropic resistivities, the resistance matrix can be used to analyze the Hall effect for anisotropic plates.
基金supported by the U.S. Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy, Advanced Manufacturing Officesupported by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Advanced Manufacturing Office, under Contract No. DE-SC0012704+1 种基金supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract DE-AC02-06CH11357supported by the Vehicle Technologies Office of the U.S. Department of Energy。
文摘Nickel-rich transition-metal oxides are widely regarded as promising cathode materials for high-energydensity lithium-ion batteries for emerging electric vehicles. However, achieving high energy density in Ni-rich cathodes is accompanied by substantial safety and cycle-life obstacles. The major issues of Ni-rich cathodes at high working potentials are originated from the unstable cathode-electrolyte interface, while the underlying mechanism of parasitic reactions towards surface reconstructions of cathode materials is not well understood. In this work, we controlled the Li_(2)CO_(3) impurity content on LiNi_(0.83)Mn_(0.1)Co_(0.07)O_(2) cathodes using air, tank-air, and O_(2) synthesis environments. Home-built high-precision leakage current and on-line electrochemical mass spectroscopy experiments verify that Li_(2)CO_(3) impurity is a significant promoter of parasitic reactions on Ni-rich cathodes. The rate of parasitic reactions is strongly correlated to Li_(2)CO_(3) content and severe performance deterioration of Ni83 cathodes.The post-mortem characterizations via high-resolution transition electron microscope and X-ray photoelectron spectroscopy depth profiles reveal that parasitic reactions promote more Ni reduction and O deficiency and even rock-salt phase transformation at the surface of cathode materials. Our observation suggests that surface reconstructions have a strong affiliation to parasitic reactions that create chemically acidic environment to etch away the lattice oxygen and offer the electrical charge to reduce the valence state of transition metal. Thus, this study advances our understanding on surface reconstructions of Nirich cathodes and prepares us for searching for rational strategies.