Fine particulate matter(PM_(2.5))and ozone(O_(3))pollutions are prevalent air quality issues in China.Volatile organic compounds(VOCs)have significant impact on the formation of O_(3)and secondary organic aerosols(SOA...Fine particulate matter(PM_(2.5))and ozone(O_(3))pollutions are prevalent air quality issues in China.Volatile organic compounds(VOCs)have significant impact on the formation of O_(3)and secondary organic aerosols(SOA)contributing PM_(2.5).Herein,we investigated 54 VOCs,O_(3)and SOA in Tianjin from June 2017 to May 2019 to explore the non-linear relationship among O_(3),SOA and VOCs.The monthly patterns of VOCs and SOA concentrations were characterized by peak values during October to March and reached a minimum from April to September,but the observed O_(3)was exactly the opposite.Machine learning methods resolved the importance of individual VOCs on O_(3)and SOA that alkenes(mainly ethylene,propylene,and isoprene)have the highest importance to O_(3)formation;alkanes(C_(n),n≥6)and aromatics were the main source of SOA formation.Machine learning methods revealed and emphasized the importance of photochemical consumptions of VOCs to O_(3)and SOA formation.Ozone formation potential(OFP)and secondary organic aerosol formation potential(SOAFP)calculated by consumed VOCs quantitatively indicated that more than 80%of the consumed VOCs were alkenes which dominated the O_(3)formation,and the importance of consumed aromatics and alkenes to SOAFP were 40.84%and 56.65%,respectively.Therein,isoprene contributed the most to OFP at 41.45%regardless of the season,while aromatics(58.27%)contributed the most to SOAFP in winter.Collectively,our findings can provide scientific evidence on policymaking for VOCs controls on seasonal scales to achieve effective reduction in both SOA and O_(3).展开更多
Phenols have been shown to influence the cellular proliferation and function of thyroid in experimental models. However, few human studies have investigated the association between phenol exposure and thyroid cancer, ...Phenols have been shown to influence the cellular proliferation and function of thyroid in experimental models. However, few human studies have investigated the association between phenol exposure and thyroid cancer, and the underlying mechanisms are also poorly understood. We conducted a case-control study by age- and sex-matching 143 thyroid cancer and 224 controls to investigate the associations between phenol exposures and the risk of thyroid cancer, and further to explore the mediating role of oxidative stress. We found that elevated urinary triclosan (TCS), bisphenol A (BPA) and bisphenol S (BPS) levels were associated with increased risk of thyroid cancer (all P for trends < 0.05), and the adjusted odds ratios (ORs) comparing the extreme exposure groups were 3.52 (95% confidence interval (CI):2.08, 5.95), 2.06 (95% CI: 1.06, 3.97) and 7.15 (95% CI: 3.12, 16.40), respectively. Positive associations were also observed between urinary TCS, BPA and BPS and three oxidative stress biomarkers measured by 8-hydroxy-2 -deoxyguanosine (8-OHdG), 8-iso-prostaglandin F(8-iso PGF) and 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA), as well as between urinary 8-iso PGFand HNE-MA and the risk of thyroid cancer. Mediation analysis showed that urinary 8-iso PGFmediated 28.95%, 47.06% and 31.08% of the associations between TCS, BPA and BPS exposures and the risk of thyroid cancer, respectively (all P < 0.05). Our results suggest that exposure to TCS, BPA and BPS may be associated with increased risk of thyroid cancer and lipid peroxidation may be an intermediate mechanism. Further studies are warranted to confirm the findings.展开更多
As one of the carriers for human communication and interaction, images are prone to contamination by noise during transmission and reception, which is often uncontrollable and unknown. Therefore, how to denoise images...As one of the carriers for human communication and interaction, images are prone to contamination by noise during transmission and reception, which is often uncontrollable and unknown. Therefore, how to denoise images contaminated by unknown noise has gradually become one of the research focuses. In order to achieve blind denoising and separation to restore images, this paper proposes a method for image processing based on Root Mean Square Error (RMSE) by integrating multiple filtering methods for denoising. This method includes Wavelet Filtering, Gaussian Filtering, Median Filtering, Mean Filtering, Bilateral Filtering, Adaptive Bandpass Filtering, Non-local Means Filtering and Regularization Denoising suitable for different types of noise. We can apply this method to denoise images contaminated by blind noise sources and evaluate the denoising effects using RMSE. The smaller the RMSE, the better the denoising effect. The optimal denoising result is selected through comprehensively comparing the RMSE values of all methods. Experimental results demonstrate that the proposed method effectively denoises and restores images contaminated by blind noise sources.展开更多
BACKGROUND Non-invasive evaluation for liver fibrosis is clinically important,especially in patients with undetectable hepatitis B virus(HBV)DNA treated with nucleoside analogs.AIM To clarify the monitoring power of h...BACKGROUND Non-invasive evaluation for liver fibrosis is clinically important,especially in patients with undetectable hepatitis B virus(HBV)DNA treated with nucleoside analogs.AIM To clarify the monitoring power of hepatitis B core-related antigen(HBcrAg)for hepatic histologic changes in patients with chronic hepatitis B(CHB)treated with entecavir.METHODS This prospective multicenter study used multiple ordinal and multivariate logistics regression analysis to assess variables associated with Ishak fibrosis score and regression for fibrosis regression,respectively,in 403 CHB patients,including 374 with entecavir for 72 weeks(291 underwent paired liver biopsy)and 29 as controls.RESULTS Level of HBcrAg correlated negatively with liver fibrosis staging(γ=-0.357,P<0.001)in hepatitis B e antigen(HBeAg)-positive patients,and positively with liver fibrosis staging in HBeAg-negative patients.Higher HBcrAg concentration was associated with younger age,HBeAg positive status,high HBV DNA loads,high level of hepatitis B surface antigen(HBsAg)and higher necroinflammation,but not with HBV genotype.Serum concentration of HBcrAg,basal core promoter/precore(BCP/PC)mutant,quantitation of HBsAg(qHBsAg)and platelet counts were independently associated with Ishak fibrosis score on multiple ordinal regression.HBV DNA was undetectable in 88.37%of patients treated with entecavir at week 72,while their level of HBcrAg was still detectable.A greater reduction in post-treatment HBcrAg concentration was associated with the regression of hepatic fibrosis and histological improvement.HBcrAg concentration>6.33 log IU/mL at baseline and logarithmic reduction>1.03 log IU/mL at week 72 were associated with a higher chance of regression of liver fibrosis and histological improvement,respectively.CONCLUSION HBcrAg level is associated with liver fibrosis progression.HBcrAg is an excellent monitor of hepatic histological changes,especially in CHB patients treated with nucleoside analogs.展开更多
Studies have shown that per-and polyfluoroalkyl substances(PFASs)may be hepatotoxic in animals or humans.However,data on clinical epidemiology are very limited.In this study,21PFASs were determined in patients with li...Studies have shown that per-and polyfluoroalkyl substances(PFASs)may be hepatotoxic in animals or humans.However,data on clinical epidemiology are very limited.In this study,21PFASs were determined in patients with liver diseases,with the highest median concentrations detected in the serum sample(26.7 ng/mL),followed by blood(10.7 ng/mL)and urine(5.02 ng/mL).Higher total PFAS concentrations were found in hepatocellular carcinoma(HCC)patients compared to non-HCC patients,with significant discrepancies in serum and blood samples.Besides,significant correlations were also found among PFAS concentrations and age,gender,body mass index(BMI),and liver function biomarkers levels.For example,PFAS concentrations are significantly higher in males than in females;Several serum PFASs concentrations increase with age and BMI,while the serum perfluorohexane sulfonic acid(PFHxS)concentrations are negatively correlated with age.In addition,multiple regression models adjusted for age,gender and BMI found that increased serum perfluorobutane sulfonic acid(PFBS),perfluoroheptane sulfonic acid(PFHpS)and perfluorohexylphosphonic acid(PFHxPA)conentrations are correlated with elevated alkaline phosphatase(ALP),aspartate aminotransferase(AST),and alpha-fetoprotein(AFP)(p<0.05).Our results provide epidemiological support for the future study on the potential clinical hepatotoxicity of PFAS.展开更多
Columnar nanocrystalline aluminum nitride(cnc-AlN) thin films with(002) orientation and uniform texture have been deposited successfully on large silicon wafers by RF reactive magnetron sputtering.At the optimum sputt...Columnar nanocrystalline aluminum nitride(cnc-AlN) thin films with(002) orientation and uniform texture have been deposited successfully on large silicon wafers by RF reactive magnetron sputtering.At the optimum sputtering parameters, the deposited cnc-AlN thin films show a c-axis preferred orientation with a crystallite size of about 28 nm and surface roughness(RMS) of about 1.29 nm. The cnc-AlN thin films were well transparent with an optical band gap about 4.8 e V, and the residual compressive stress and the defect density in the film have been revealed by Ramon spectroscopy. Moreover, piezoelectric performances of the cnc-AlN thin films executed effectively in a film bulk acoustic resonator structure.展开更多
Precipitation-hardened high entropy alloys(HEAs)with carefully tuned compositions have shown excellent mechanical properties,demonstrating great potential for engineering applications.However,due to the lack of precis...Precipitation-hardened high entropy alloys(HEAs)with carefully tuned compositions have shown excellent mechanical properties,demonstrating great potential for engineering applications.However,due to the lack of precise multiple phase diagrams,the composition design of multi-principal-component HEAs still inevitably relies on the extremely time-consuming trial-and-error approach.The present study,on the basis of powerful composition quantification ability of atom probe tomography(APT)technology,proposed a framework to guide the quantitative design of precipitation-hardened HEAs.In this framework,the elemental partitioning was used as a crucial route to avoid the thermodynamic challenge of designing precipitation-hardened HEAs.As a case study,the role of Ti/Al ratio in the design ofγ-γ’HEAs was predicted through the proposed framework and then validated by experimental studies.The framework predicted that when the total content of Ti and Al is fixed,a higher Ti/Al ratio makesγ-γ’HEA stronger.APT and mechanical results agreed well with these predictions and validated the feasibility of the framework.These findings provided a new route to design the precipitation-hardened alloys and a deeper insight into the design ofγ-γ’HEA.展开更多
Ultra-Dense Network （UDN） is considered to be the key enabler for realizing capacity goals set by 5G. The major concern in UDN deployment is the backhaul network, which should be scalable, cost-effective, and have s...Ultra-Dense Network （UDN） is considered to be the key enabler for realizing capacity goals set by 5G. The major concern in UDN deployment is the backhaul network, which should be scalable, cost-effective, and have sufficient capacity to support massive small cell traffic. Otherwise, the backhaul can become the bottleneck of the network. In this paper, we propose a wireless backhaul solution for UDN deployment by considering MultiPath-MultiHop （MPMH） backhaul architecture in mmWave frequency band. In addition, we propose a distributed routing scheme to forward the backhaul traffic over the multihop network. Backhaul capacity and line-of-sight probability of the proposed backhaul architecture for various picocell densities were compared with direct, multiple-association, and multihop backhaul schemes under interference limited scenarios in outdoor and indoor small cell deployments. The simulation results indicate that the MPMH mmWave backhaul is the most cost-effective and scalable solution for UDN deployment.展开更多
License assisted access(LAA) was proposed as a solution to the challenge of satisfying high throughput requirement in cellular network with limited licensed band. LAA uses long term evolution(LTE) carrier aggregation ...License assisted access(LAA) was proposed as a solution to the challenge of satisfying high throughput requirement in cellular network with limited licensed band. LAA uses long term evolution(LTE) carrier aggregation technique to combine licensed and unlicensed bands, specifically 5 GHz Wi Fi band, in order to achieve high data rates. However, LAA has several critical concerns for services provision on 5 GHz unlicensed band. In this article, an overview of the techniques concerning the coexistence of LTE and Wi Fi on the same unlicensed band is presented. We first present several general approaches including power control of LTE evolved Node B(e NB), carrier selection, LTE duty cycling, self clear to send(CTS) and request to send/CTS(RTS/CTS), and listen before talk(LBT). Then, we focus on LBT techniques for LAA-Wi Fi coexistence and discuss how LBT based coexistence solutions can dynamically respond to the variations in network load and ensure fair coexistence in a distributed manner. Based on the LBT mechanism, we also present a fairness-aware LAA-WiF i coexisting scheme with TXOP(transmitted in a single transmission opportunity) backoff for LAA e NB. Finally, the performances of various LBT solutions for LAA-Wi Fi coexistence are evaluated using Markov chain analytical model.展开更多
Triclosan(TCS)is a ubiquitous antimicrobial used in daily consumer products.Previous reports have shown that TCS could induce hepatotoxicity,endocrine disruption,disturbance on immune function and impaired thyroid fun...Triclosan(TCS)is a ubiquitous antimicrobial used in daily consumer products.Previous reports have shown that TCS could induce hepatotoxicity,endocrine disruption,disturbance on immune function and impaired thyroid function.Kidney is critical in the elimination of toxins,while the effects of TCS on kidney have not yet been well-characterized.The aim of the present study was to investigate the effects of TCS exposure on kidney function and the possible underlying mechanisms in mice.Male C57BL/6 mice were orally exposed to TCS with the doses of 10 and 100 mg/(kg•day)for 13 weeks.TCS was dissolved in dimethyl sulfoxide(DMSO)and diluted by corn oil for exposure.Corn oil containing DMSO was used as vehicle control.Serum and kidney tissues were collected for study.Biomarkers associated with kidney function,oxidative stress,inflammation and fibrosis were assessed.Our results showed that TCS could cause renal injury as was revealed by increased levels of renal function markers including serum creatinine,urea nitrogen and uric acid,as well as increased oxidative stress,pro-inflammatory cytokines and fibroticmarkers in a dose dependent manner,whichweremore significantly in 100 mg/(kg•day)group.Mass spectrometry-based analysis of metabolites relatedwith lipid metabolism demonstrated the occurrence of lipid accumulation and defective fatty acid oxidation in 100 mg/(kg•day)TCS-exposed mouse kidney.These processes might lead to lipotoxicity and energy depletion,thus resulting in kidney fibrosis and functional decline.Taken together,the present study demonstrated that TCS could induce lipid accumulation and fatty acid metabolism disturbance in mouse kidney,whichmight contribute to renal function impairment.The present study further widens our insights into the adverse effects of TCS.展开更多
We apply a Peak Shrinking and Interpolating(PSI)scheme to improve the Peak-to-Average Power Ratio(PAPR)performance in Multiple Intermediate-Frequency-over-Fiber(M-IFoF)based mobile fronthaul.The key idea is to detect ...We apply a Peak Shrinking and Interpolating(PSI)scheme to improve the Peak-to-Average Power Ratio(PAPR)performance in Multiple Intermediate-Frequency-over-Fiber(M-IFoF)based mobile fronthaul.The key idea is to detect the high peaks of the signal and shrink them,and then the shrunk peak values are interpolated into the original signal to reduce the PAPR.We also compare the PSI technique with the previous Tone-Reservation(TR)technique and Phase Pre-Distortion(PPD)technique in terms of PAPR reduction effect and computational complexity.The simulation results indicate that the PSI scheme can reduce the PAPR by more than 4.3 dB at 0.1%CCDF,which outperforms the two previous schemes with lower computational complexity.Furthermore,we find that altering M-IFoF system parameters has little effect on the performance of the PSI technique.展开更多
To overcome the low efficiency of conventional confocal Raman spectroscopy,many efforts have been devoted to parallelizing the Raman excitation and acquisition,in which the scattering from multiple foci is projected o...To overcome the low efficiency of conventional confocal Raman spectroscopy,many efforts have been devoted to parallelizing the Raman excitation and acquisition,in which the scattering from multiple foci is projected onto different locations on a spectrometer's CCD,along either its vertical,horizontal dimension,or even both.While the latter projection scheme relieves the limitation on the row numbers of the CCD,the spectra of multiple foci are recorded in one spectral channel,resulting in spectral overlapping.Here,we developed a method under a com-pressive sensing framework to demultiplex the superimposed spectra of multiple cells during their dynamic processes.Unlike the previous methods which ignore the information connection be-tween the spectra of the cells recorded at different time,the proposed method utilizes a prior that a cell's spectra acquired at different time have the same sparsity structure in their principal components.Rather than independently demultiplexing the mixed spectra at the individual time intervals,the method demultiplexes the whole spectral sequence acquired continuously during the dynamic process.By penalizing the sparsity combined from all time intervals,the collaborative optimization of the inversion problem gave more accurate recovery results.The performances of the method were substantiated by a 1D Raman tweezers array,which monitored the germination of multiple bacterial spores.The method can be extended to the monitoring of many living cells randomly scattering on a coverslip,and has a potential to improve the throughput by a few orders.展开更多
BACKGROUND Cognitive dysfunction is the main manifestation of central neuropathy.Although cognitive impairments tend to be overlooked in patients with diabetes mellitus(DM),there is a growing body of evidence linking ...BACKGROUND Cognitive dysfunction is the main manifestation of central neuropathy.Although cognitive impairments tend to be overlooked in patients with diabetes mellitus(DM),there is a growing body of evidence linking DM to cognitive dysfunction.Hyperglycemia is closely related to neurological abnormalities,while often disregarded in clinical practice.Changes in cerebral neurotransmitter levels are associated with a variety of neurological abnormalities and may be closely related to blood glucose control in patients with type 2 DM(T2DM).AIM To evaluate the concentrations of cerebral neurotransmitters in T2DM patients exhibiting different hemoglobin A1c(HbA1c)levels.METHODS A total of 130 T2DM patients were enrolled at the Department of Endocrinology of Shanghai East Hospital.The participants were divided into four groups according to their HbA1c levels using the interquartile method,namely Q1(<7.875%),Q2(7.875%-9.050%),Q3(9.050%-11.200%)and Q4(≥11.200%).Clinical data were collected and measured,including age,height,weight,neck/waist/hip circumferences,blood pressure,comorbidities,duration of DM,and biochemical indicators.Meanwhile,neurotransmitters in the left hippocampus and left brainstem area were detected by proton magnetic resonance spectroscopy.RESULTS The HbA1c level was significantly associated with urinary microalbumin(mALB),triglyceride,low-density lipoprotein cholesterol(LDL-C),homeostasis model assessment of insulin resistance(HOMA-IR),and beta cell function(HOMA-β),N-acetylaspartate/creatine(NAA/Cr),and NAA/choline(NAA/Cho).Spearman correlation analysis showed that mALB,LDL-C,HOMA-IR and NAA/Cr in the left brainstem area were positively correlated with the level of HbA1c(P<0.05),whereas HOMA-βwas negatively correlated with the HbA1c level(P<0.05).Ordered multiple logistic regression analysis showed that NAA/Cho[Odds ratio(OR):1.608,95%confidence interval(95%CI):1.004-2.578,P<0.05],LDL-C(OR:1.627,95%CI:1.119-2.370,P<0.05),and HOMA-IR(OR:1.107,95%CI:1.031-1.188,P<0.01)were independent predictors of poor glycemic control.CONCLUSION The cerebral neurotransmitter concentrations in the left brainstem area in patients with T2DM are closely related to glycemic control,which may be the basis for the changes in cognitive function in diabetic patients.展开更多
There have been considerable research efforts on developing the enabling technologies for the next generation of wireless communication systems all over the world, leading towards the future 5G and beyond 5G wireless ...There have been considerable research efforts on developing the enabling technologies for the next generation of wireless communication systems all over the world, leading towards the future 5G and beyond 5G wireless systems. The key demands now are user-eentric （instead of the traditional carrier-centric） mobile applications, high mobile data traffic volume, large number of connected devices, long device/network lifetime, improved Quality of Services （QoS） and Quality of Experience （QoE） for users, i.e., high-transmission rate, low delay, and small jitter etc. In recent years, a lot of promising wireless technologies have been proposed or developed to improve the quality of wireless communications and to enable new wireless applications. Such technologies are focused on new spectrum such as millimeter wave, wider bandwidths, new modulation techniques, enhanced small cells, massive MIMO, and so on.展开更多
Aiming at the issue of the selectivity of routing protocols between UAV groups, a comprehensive weighting evaluation system based on game theory is proposed. Taking network simulation data as an example, three protoco...Aiming at the issue of the selectivity of routing protocols between UAV groups, a comprehensive weighting evaluation system based on game theory is proposed. Taking network simulation data as an example, three protocols, AODV, DSDV, and OLSR, are selected as the research objects. The results show that the DSDV protocol is suitable for the simple communication environment between UAV groups, the AODV protocol is suitable for the complex communication environment between UAV groups. In addition, the evaluation system is compared with the two evaluation systems of the Covariance Analytic Hierarchy Process (Cov-AHP) and the entropy method to calculate the relative deviation. The comparison results show that the new evaluation system is more reasonable than the other two evaluation systems.展开更多
基金financially supported by the National Key Research and Development Program of China(No.2018 YFE0106900)supported by National Natural Science Foundation of China(Nos.42077191,41775149)+2 种基金Fundamental Research Funds for the Central Universities(No.63213072)National Research Program for Key Issues in Air Pollution Control(No.DQGG-05-30)the Blue Sky Foundation
文摘Fine particulate matter(PM_(2.5))and ozone(O_(3))pollutions are prevalent air quality issues in China.Volatile organic compounds(VOCs)have significant impact on the formation of O_(3)and secondary organic aerosols(SOA)contributing PM_(2.5).Herein,we investigated 54 VOCs,O_(3)and SOA in Tianjin from June 2017 to May 2019 to explore the non-linear relationship among O_(3),SOA and VOCs.The monthly patterns of VOCs and SOA concentrations were characterized by peak values during October to March and reached a minimum from April to September,but the observed O_(3)was exactly the opposite.Machine learning methods resolved the importance of individual VOCs on O_(3)and SOA that alkenes(mainly ethylene,propylene,and isoprene)have the highest importance to O_(3)formation;alkanes(C_(n),n≥6)and aromatics were the main source of SOA formation.Machine learning methods revealed and emphasized the importance of photochemical consumptions of VOCs to O_(3)and SOA formation.Ozone formation potential(OFP)and secondary organic aerosol formation potential(SOAFP)calculated by consumed VOCs quantitatively indicated that more than 80%of the consumed VOCs were alkenes which dominated the O_(3)formation,and the importance of consumed aromatics and alkenes to SOAFP were 40.84%and 56.65%,respectively.Therein,isoprene contributed the most to OFP at 41.45%regardless of the season,while aromatics(58.27%)contributed the most to SOAFP in winter.Collectively,our findings can provide scientific evidence on policymaking for VOCs controls on seasonal scales to achieve effective reduction in both SOA and O_(3).
基金supported by the National Natural Science Foundation of China (No. 81872585)the National Key Research and Development Program of China (No. 2016YFC1302700)。
文摘Phenols have been shown to influence the cellular proliferation and function of thyroid in experimental models. However, few human studies have investigated the association between phenol exposure and thyroid cancer, and the underlying mechanisms are also poorly understood. We conducted a case-control study by age- and sex-matching 143 thyroid cancer and 224 controls to investigate the associations between phenol exposures and the risk of thyroid cancer, and further to explore the mediating role of oxidative stress. We found that elevated urinary triclosan (TCS), bisphenol A (BPA) and bisphenol S (BPS) levels were associated with increased risk of thyroid cancer (all P for trends < 0.05), and the adjusted odds ratios (ORs) comparing the extreme exposure groups were 3.52 (95% confidence interval (CI):2.08, 5.95), 2.06 (95% CI: 1.06, 3.97) and 7.15 (95% CI: 3.12, 16.40), respectively. Positive associations were also observed between urinary TCS, BPA and BPS and three oxidative stress biomarkers measured by 8-hydroxy-2 -deoxyguanosine (8-OHdG), 8-iso-prostaglandin F(8-iso PGF) and 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA), as well as between urinary 8-iso PGFand HNE-MA and the risk of thyroid cancer. Mediation analysis showed that urinary 8-iso PGFmediated 28.95%, 47.06% and 31.08% of the associations between TCS, BPA and BPS exposures and the risk of thyroid cancer, respectively (all P < 0.05). Our results suggest that exposure to TCS, BPA and BPS may be associated with increased risk of thyroid cancer and lipid peroxidation may be an intermediate mechanism. Further studies are warranted to confirm the findings.
文摘As one of the carriers for human communication and interaction, images are prone to contamination by noise during transmission and reception, which is often uncontrollable and unknown. Therefore, how to denoise images contaminated by unknown noise has gradually become one of the research focuses. In order to achieve blind denoising and separation to restore images, this paper proposes a method for image processing based on Root Mean Square Error (RMSE) by integrating multiple filtering methods for denoising. This method includes Wavelet Filtering, Gaussian Filtering, Median Filtering, Mean Filtering, Bilateral Filtering, Adaptive Bandpass Filtering, Non-local Means Filtering and Regularization Denoising suitable for different types of noise. We can apply this method to denoise images contaminated by blind noise sources and evaluate the denoising effects using RMSE. The smaller the RMSE, the better the denoising effect. The optimal denoising result is selected through comprehensively comparing the RMSE values of all methods. Experimental results demonstrate that the proposed method effectively denoises and restores images contaminated by blind noise sources.
基金Supported by Chinese Ministry of Science and Technology Grants the Major Science and Technology Special Project Fund Scheme,No.2013ZX10005002Beijing the Special Clinical Application Research and Translational Grants,No.Z151100004015221
文摘BACKGROUND Non-invasive evaluation for liver fibrosis is clinically important,especially in patients with undetectable hepatitis B virus(HBV)DNA treated with nucleoside analogs.AIM To clarify the monitoring power of hepatitis B core-related antigen(HBcrAg)for hepatic histologic changes in patients with chronic hepatitis B(CHB)treated with entecavir.METHODS This prospective multicenter study used multiple ordinal and multivariate logistics regression analysis to assess variables associated with Ishak fibrosis score and regression for fibrosis regression,respectively,in 403 CHB patients,including 374 with entecavir for 72 weeks(291 underwent paired liver biopsy)and 29 as controls.RESULTS Level of HBcrAg correlated negatively with liver fibrosis staging(γ=-0.357,P<0.001)in hepatitis B e antigen(HBeAg)-positive patients,and positively with liver fibrosis staging in HBeAg-negative patients.Higher HBcrAg concentration was associated with younger age,HBeAg positive status,high HBV DNA loads,high level of hepatitis B surface antigen(HBsAg)and higher necroinflammation,but not with HBV genotype.Serum concentration of HBcrAg,basal core promoter/precore(BCP/PC)mutant,quantitation of HBsAg(qHBsAg)and platelet counts were independently associated with Ishak fibrosis score on multiple ordinal regression.HBV DNA was undetectable in 88.37%of patients treated with entecavir at week 72,while their level of HBcrAg was still detectable.A greater reduction in post-treatment HBcrAg concentration was associated with the regression of hepatic fibrosis and histological improvement.HBcrAg concentration>6.33 log IU/mL at baseline and logarithmic reduction>1.03 log IU/mL at week 72 were associated with a higher chance of regression of liver fibrosis and histological improvement,respectively.CONCLUSION HBcrAg level is associated with liver fibrosis progression.HBcrAg is an excellent monitor of hepatic histological changes,especially in CHB patients treated with nucleoside analogs.
基金supported by the National Natural Science Foundation of China(No.42177408)Guangdong(China)Innovative and Entrepreneurial Research Team Program(No.2016ZT06N258)。
文摘Studies have shown that per-and polyfluoroalkyl substances(PFASs)may be hepatotoxic in animals or humans.However,data on clinical epidemiology are very limited.In this study,21PFASs were determined in patients with liver diseases,with the highest median concentrations detected in the serum sample(26.7 ng/mL),followed by blood(10.7 ng/mL)and urine(5.02 ng/mL).Higher total PFAS concentrations were found in hepatocellular carcinoma(HCC)patients compared to non-HCC patients,with significant discrepancies in serum and blood samples.Besides,significant correlations were also found among PFAS concentrations and age,gender,body mass index(BMI),and liver function biomarkers levels.For example,PFAS concentrations are significantly higher in males than in females;Several serum PFASs concentrations increase with age and BMI,while the serum perfluorohexane sulfonic acid(PFHxS)concentrations are negatively correlated with age.In addition,multiple regression models adjusted for age,gender and BMI found that increased serum perfluorobutane sulfonic acid(PFBS),perfluoroheptane sulfonic acid(PFHpS)and perfluorohexylphosphonic acid(PFHxPA)conentrations are correlated with elevated alkaline phosphatase(ALP),aspartate aminotransferase(AST),and alpha-fetoprotein(AFP)(p<0.05).Our results provide epidemiological support for the future study on the potential clinical hepatotoxicity of PFAS.
文摘Columnar nanocrystalline aluminum nitride(cnc-AlN) thin films with(002) orientation and uniform texture have been deposited successfully on large silicon wafers by RF reactive magnetron sputtering.At the optimum sputtering parameters, the deposited cnc-AlN thin films show a c-axis preferred orientation with a crystallite size of about 28 nm and surface roughness(RMS) of about 1.29 nm. The cnc-AlN thin films were well transparent with an optical band gap about 4.8 e V, and the residual compressive stress and the defect density in the film have been revealed by Ramon spectroscopy. Moreover, piezoelectric performances of the cnc-AlN thin films executed effectively in a film bulk acoustic resonator structure.
基金financially supported by the Hong Kong Research Grant Council(Nos.CityU 11212915 and CityU 11205018)the National Natural Science foundation of China(Nos.51771149,52001266+1 种基金51901119)Natural Science Foundation of ShaanXi Province in China(No.2020JQ-720)。
文摘Precipitation-hardened high entropy alloys(HEAs)with carefully tuned compositions have shown excellent mechanical properties,demonstrating great potential for engineering applications.However,due to the lack of precise multiple phase diagrams,the composition design of multi-principal-component HEAs still inevitably relies on the extremely time-consuming trial-and-error approach.The present study,on the basis of powerful composition quantification ability of atom probe tomography(APT)technology,proposed a framework to guide the quantitative design of precipitation-hardened HEAs.In this framework,the elemental partitioning was used as a crucial route to avoid the thermodynamic challenge of designing precipitation-hardened HEAs.As a case study,the role of Ti/Al ratio in the design ofγ-γ’HEAs was predicted through the proposed framework and then validated by experimental studies.The framework predicted that when the total content of Ti and Al is fixed,a higher Ti/Al ratio makesγ-γ’HEA stronger.APT and mechanical results agreed well with these predictions and validated the feasibility of the framework.These findings provided a new route to design the precipitation-hardened alloys and a deeper insight into the design ofγ-γ’HEA.
基金This work was supported in part by the National Science Foundation for Distinguished Young Scholars of China with Grant number 61325004 as well as the National Science Foundation of China with Grants 61771216 and 61601191.
文摘Ultra-Dense Network （UDN） is considered to be the key enabler for realizing capacity goals set by 5G. The major concern in UDN deployment is the backhaul network, which should be scalable, cost-effective, and have sufficient capacity to support massive small cell traffic. Otherwise, the backhaul can become the bottleneck of the network. In this paper, we propose a wireless backhaul solution for UDN deployment by considering MultiPath-MultiHop （MPMH） backhaul architecture in mmWave frequency band. In addition, we propose a distributed routing scheme to forward the backhaul traffic over the multihop network. Backhaul capacity and line-of-sight probability of the proposed backhaul architecture for various picocell densities were compared with direct, multiple-association, and multihop backhaul schemes under interference limited scenarios in outdoor and indoor small cell deployments. The simulation results indicate that the MPMH mmWave backhaul is the most cost-effective and scalable solution for UDN deployment.
基金supported in part by Joint Specialized Research Fund for the Doctoral Program of Higher Education (SRFDP) and Research Grants Council Earmarked Research Grants (RGC ERG) with Grant 20130142140002National Science Foundation of China with Grants 61531011 and 61471163Major Program of National Natural Science Foundation of Hubei in China with Grant 2016CFA009
文摘License assisted access(LAA) was proposed as a solution to the challenge of satisfying high throughput requirement in cellular network with limited licensed band. LAA uses long term evolution(LTE) carrier aggregation technique to combine licensed and unlicensed bands, specifically 5 GHz Wi Fi band, in order to achieve high data rates. However, LAA has several critical concerns for services provision on 5 GHz unlicensed band. In this article, an overview of the techniques concerning the coexistence of LTE and Wi Fi on the same unlicensed band is presented. We first present several general approaches including power control of LTE evolved Node B(e NB), carrier selection, LTE duty cycling, self clear to send(CTS) and request to send/CTS(RTS/CTS), and listen before talk(LBT). Then, we focus on LBT techniques for LAA-Wi Fi coexistence and discuss how LBT based coexistence solutions can dynamically respond to the variations in network load and ensure fair coexistence in a distributed manner. Based on the LBT mechanism, we also present a fairness-aware LAA-WiF i coexisting scheme with TXOP(transmitted in a single transmission opportunity) backoff for LAA e NB. Finally, the performances of various LBT solutions for LAA-Wi Fi coexistence are evaluated using Markov chain analytical model.
基金Project supported by the National Natural Science Foundation of China(No.51408186)the Natural Science Foundation of Jiangsu Province(Nos.BK20140853 and BK20130843)the Program of Introducing Talents of Discipline to Universities(No.B12032),China
基金supported by the National Natural Science Foundation of China (No. 21806135)the General Research Fund (No. 12301518) from Research Grants Council of Hong Kong
文摘Triclosan(TCS)is a ubiquitous antimicrobial used in daily consumer products.Previous reports have shown that TCS could induce hepatotoxicity,endocrine disruption,disturbance on immune function and impaired thyroid function.Kidney is critical in the elimination of toxins,while the effects of TCS on kidney have not yet been well-characterized.The aim of the present study was to investigate the effects of TCS exposure on kidney function and the possible underlying mechanisms in mice.Male C57BL/6 mice were orally exposed to TCS with the doses of 10 and 100 mg/(kg•day)for 13 weeks.TCS was dissolved in dimethyl sulfoxide(DMSO)and diluted by corn oil for exposure.Corn oil containing DMSO was used as vehicle control.Serum and kidney tissues were collected for study.Biomarkers associated with kidney function,oxidative stress,inflammation and fibrosis were assessed.Our results showed that TCS could cause renal injury as was revealed by increased levels of renal function markers including serum creatinine,urea nitrogen and uric acid,as well as increased oxidative stress,pro-inflammatory cytokines and fibroticmarkers in a dose dependent manner,whichweremore significantly in 100 mg/(kg•day)group.Mass spectrometry-based analysis of metabolites relatedwith lipid metabolism demonstrated the occurrence of lipid accumulation and defective fatty acid oxidation in 100 mg/(kg•day)TCS-exposed mouse kidney.These processes might lead to lipotoxicity and energy depletion,thus resulting in kidney fibrosis and functional decline.Taken together,the present study demonstrated that TCS could induce lipid accumulation and fatty acid metabolism disturbance in mouse kidney,whichmight contribute to renal function impairment.The present study further widens our insights into the adverse effects of TCS.
文摘We apply a Peak Shrinking and Interpolating(PSI)scheme to improve the Peak-to-Average Power Ratio(PAPR)performance in Multiple Intermediate-Frequency-over-Fiber(M-IFoF)based mobile fronthaul.The key idea is to detect the high peaks of the signal and shrink them,and then the shrunk peak values are interpolated into the original signal to reduce the PAPR.We also compare the PSI technique with the previous Tone-Reservation(TR)technique and Phase Pre-Distortion(PPD)technique in terms of PAPR reduction effect and computational complexity.The simulation results indicate that the PSI scheme can reduce the PAPR by more than 4.3 dB at 0.1%CCDF,which outperforms the two previous schemes with lower computational complexity.Furthermore,we find that altering M-IFoF system parameters has little effect on the performance of the PSI technique.
基金This work was supported by the National Key R&D Program of China(2019YFC1605500,2018YFF01011700)the National Natural Science Foundation of China(21973111)+1 种基金Guangxi Natural Science Foundation(2017GXNSFAA198029)Scientific Development Fund of Guangxi Academy of Sciences(2018YFJ 403).
文摘To overcome the low efficiency of conventional confocal Raman spectroscopy,many efforts have been devoted to parallelizing the Raman excitation and acquisition,in which the scattering from multiple foci is projected onto different locations on a spectrometer's CCD,along either its vertical,horizontal dimension,or even both.While the latter projection scheme relieves the limitation on the row numbers of the CCD,the spectra of multiple foci are recorded in one spectral channel,resulting in spectral overlapping.Here,we developed a method under a com-pressive sensing framework to demultiplex the superimposed spectra of multiple cells during their dynamic processes.Unlike the previous methods which ignore the information connection be-tween the spectra of the cells recorded at different time,the proposed method utilizes a prior that a cell's spectra acquired at different time have the same sparsity structure in their principal components.Rather than independently demultiplexing the mixed spectra at the individual time intervals,the method demultiplexes the whole spectral sequence acquired continuously during the dynamic process.By penalizing the sparsity combined from all time intervals,the collaborative optimization of the inversion problem gave more accurate recovery results.The performances of the method were substantiated by a 1D Raman tweezers array,which monitored the germination of multiple bacterial spores.The method can be extended to the monitoring of many living cells randomly scattering on a coverslip,and has a potential to improve the throughput by a few orders.
基金Supported by the Academic Leaders Training Program of Pudong Health Bureau of Shanghai,No.PWRd2023-03Clinical Research Fund of Shanghai Municipal Commission of Health,No.202040136+1 种基金National Natural Science Foundation of China,No.82070842Jiangxi Health Commission Science and Technology Plan Project,No.202212838 and No.202212852.
文摘BACKGROUND Cognitive dysfunction is the main manifestation of central neuropathy.Although cognitive impairments tend to be overlooked in patients with diabetes mellitus(DM),there is a growing body of evidence linking DM to cognitive dysfunction.Hyperglycemia is closely related to neurological abnormalities,while often disregarded in clinical practice.Changes in cerebral neurotransmitter levels are associated with a variety of neurological abnormalities and may be closely related to blood glucose control in patients with type 2 DM(T2DM).AIM To evaluate the concentrations of cerebral neurotransmitters in T2DM patients exhibiting different hemoglobin A1c(HbA1c)levels.METHODS A total of 130 T2DM patients were enrolled at the Department of Endocrinology of Shanghai East Hospital.The participants were divided into four groups according to their HbA1c levels using the interquartile method,namely Q1(<7.875%),Q2(7.875%-9.050%),Q3(9.050%-11.200%)and Q4(≥11.200%).Clinical data were collected and measured,including age,height,weight,neck/waist/hip circumferences,blood pressure,comorbidities,duration of DM,and biochemical indicators.Meanwhile,neurotransmitters in the left hippocampus and left brainstem area were detected by proton magnetic resonance spectroscopy.RESULTS The HbA1c level was significantly associated with urinary microalbumin(mALB),triglyceride,low-density lipoprotein cholesterol(LDL-C),homeostasis model assessment of insulin resistance(HOMA-IR),and beta cell function(HOMA-β),N-acetylaspartate/creatine(NAA/Cr),and NAA/choline(NAA/Cho).Spearman correlation analysis showed that mALB,LDL-C,HOMA-IR and NAA/Cr in the left brainstem area were positively correlated with the level of HbA1c(P<0.05),whereas HOMA-βwas negatively correlated with the HbA1c level(P<0.05).Ordered multiple logistic regression analysis showed that NAA/Cho[Odds ratio(OR):1.608,95%confidence interval(95%CI):1.004-2.578,P<0.05],LDL-C(OR:1.627,95%CI:1.119-2.370,P<0.05),and HOMA-IR(OR:1.107,95%CI:1.031-1.188,P<0.01)were independent predictors of poor glycemic control.CONCLUSION The cerebral neurotransmitter concentrations in the left brainstem area in patients with T2DM are closely related to glycemic control,which may be the basis for the changes in cognitive function in diabetic patients.
基金Acknowledgments Tao Jiang＇s work is supported in part by the National Science Foundation for Distinguished Young Scholars of China with Grant number 61325004 and National Science Foundation of China with Grants 61428104 and 61631015, National High Technology Development 863 Program of China under Grants 2015AA01AT10 and 2014AAO1A704, the Key Project of Hubei Province in China with Grant 2015BAA074. Shiwen Mao＇s work is supported in part by the US National Science Foundation under grants CNS-1247955 and CNS-1320664, and by the Wireless Engineering Research and Education Center （WEREC） at Auburn University.
文摘There have been considerable research efforts on developing the enabling technologies for the next generation of wireless communication systems all over the world, leading towards the future 5G and beyond 5G wireless systems. The key demands now are user-eentric （instead of the traditional carrier-centric） mobile applications, high mobile data traffic volume, large number of connected devices, long device/network lifetime, improved Quality of Services （QoS） and Quality of Experience （QoE） for users, i.e., high-transmission rate, low delay, and small jitter etc. In recent years, a lot of promising wireless technologies have been proposed or developed to improve the quality of wireless communications and to enable new wireless applications. Such technologies are focused on new spectrum such as millimeter wave, wider bandwidths, new modulation techniques, enhanced small cells, massive MIMO, and so on.
文摘Aiming at the issue of the selectivity of routing protocols between UAV groups, a comprehensive weighting evaluation system based on game theory is proposed. Taking network simulation data as an example, three protocols, AODV, DSDV, and OLSR, are selected as the research objects. The results show that the DSDV protocol is suitable for the simple communication environment between UAV groups, the AODV protocol is suitable for the complex communication environment between UAV groups. In addition, the evaluation system is compared with the two evaluation systems of the Covariance Analytic Hierarchy Process (Cov-AHP) and the entropy method to calculate the relative deviation. The comparison results show that the new evaluation system is more reasonable than the other two evaluation systems.
