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Multilevel inverters are becoming more and more popular in photovoltaic (PV) applications because of lower total harmonic distortion (THD), lower switching stress and electromagnetic interference (EMI). In this paper, a single-phase five-level transformer-less PV inverter is proposed for the purpose of leakage current reduction. The inverter is based on a flying capacitor (FC) configuration, the voltages of FCs are balanced at Vdc/4 through the coordination of the two half-bridge at the switching frequency, helps to reduce investment cost in passive elements. Two bidirectional circuits are added to guarantee a constant common-mode (CM) voltage. The leakage current elimination mechanism is analyzed in detail with operational states and CM equivalent model. The losses are analyzed, the control strategy and the FCs are detailed designed. A comparison is also made in terms of the number of elements, voltage stress and CM voltage. Experiment results under grid-connected condition show that the proposed topology achieves excellent both differential-mode and CM performance.

The single-phase five-level transformerless inverters have been gradually applied in photovoltaic grid-connected systems due to low voltage stress and excellent waveform quality. However, they also suffer from serious leakage current as conventional three-level inverters. In order to reduce the leakage current, a single-phase five-level transformerless inverter is proposed in this article. The proposed inverter guarantees that the common-mode (CM) voltage is clamped to a half of the dc-link voltage when outputting ± V dc/2 and zero voltage levels. Consequently, the high-frequency CM voltage is avoided and the leakage current is suppressed. The voltage stresses of eight switches and two flying capacitors are only V dc/4, thus the system investment cost and total losses are reduced. The conduction and switching losses are analyzed in detail and a comparison with some existing topologies is also made. Finally, simulations and experiment are carried out based on a 1-kW prototype. The results show that the proposed single-phase five-level inverter can obtain both excellent differential-mode and CM performance.

Migrants’ socio-economic integration is a major theme in migration research, which can provide economic and cultural benefits. And it will contribute to social stability. The investigation from the spatial perspective should also be considered. This paper aims to examine the spatial differentiation of the socio-economic integration of migrants and identify its driving forces to provide crucial evidence and policy recommendations to urban policymakers and further improve migrants’ socio-economic integration. Based on the latest China Migrants Dynamic Survey, this paper uses global Moran’s I index, hot spot analysis and GWR model to explore spatial differentiation and driving forces of the socio-economic integration of 155,789 migrants in 291 cities at prefecture level and above in China. The results show that: (1) The socio-economic integration of migrants consists of five dimensions, which are economic integration, cultural integration, social security, social relation and psychological integration. Among them, psychological integration is the highest (73.16) and economic integration is the lowest (13.38). (2) The socio-economic integration of migrants is mainly influenced by their own characteristics instead of the destination characteristics. Four factors (age, education, length of stay and population growth rate) positively affect migrants’ socio-economic integration, while three factors (inter-provincial mobility, proportion of tertiary industry in GDP, and ratio of teacher to student in middle school) negatively impact the socio-economic integration of migrants. (3) The socio-economic integration of migrants shows the distribution pattern of agglomeration. And the integration also presents a significant spatial heterogeneity. The driving forces of the socio-economic integration exhibit various zonal spatial differentiation patterns, including “E–W”, “SE–NW”, “NE–SW”, and “S–N”. Finally, some useful recommendations are given for improving migrants’ socio-economic integration.

On the basis of the 2013 China Migrants Dynamic Survey provided by the National Health and Family Planning Commission, we explored the impact of neighbourhood choice on the socioeconomic integration of migrants and the underlying mechanism. When problems with endogeneity were controlled, the findings showed that neighbourhood choice had a significant positive effect on the socioeconomic integration of migrants, that is, compared with migrants living in informal neighbourhoods (urban villages or outdated inner-city housing), those living in formal neighbourhoods (commercial housing, affordable housing or work unit housing neighbourhoods) displayed higher socioeconomic integration. Further research found that neighbourhood choice did not directly affect the socioeconomic integration of migrants in China, partly because migrants living in formal neighbourhoods established localized social capital (contacting local residents and government personnel, seeking help from them and increasing expenditures on local invitations and gifts) to promote better integration into the city, and they had a stronger willingness to settle down, which encouraged them to work harder, actively integrated into the mainstream society.

Background: Dairy safety has caused widespread concern in society. Unsafe dairy products have threatened people's health and lives. In order to improve the safety of dairy products and effectively prevent the occurrence of dairy insecurity, countries have established different prevention and control measures and safety warnings. Objective: The purpose of this study is to establish a dairy safety prediction model based on machine learning to determine whether the dairy products are qualified. Methods: The 34 common items in the dairy sampling inspection were used as features in this study. Feature selection was performed on the data to obtain a better subset of features, and different algorithms were applied to construct the classification model. Results: The results show that the prediction model constructed by using a subset of features including “total plate”, “water” and “nitrate” is superior. The SN, SP and ACC of the model were 62.50%, 91.67% and 72.22%, respectively. It was found that the accuracy of the model established by the integrated algorithm is higher than that by the non-integrated algorithm. Conclusion: This study provides a new method for assessing dairy safety. It helps to improve the quality of dairy products, ensure the safety of dairy products, and reduce the risk of dairy safety.

Background HIV/AIDS is a chronic disease leading to complications in infected individuals that often require surgical intervention. These patients’ serum CD4 T lymphocyte (CD4) counts represent one of the most important indicators of their ability to tolerate surgical treatment. Previous studies have demonstrated that CD4 cell count (CD4-CC) < 200 cells/μl may increase the risk of surgical complications in these patients, limiting their ability to undergo surgery, which may negatively affect their quality of life. Further investigation into the surgical outcomes of patients with CD4-CC < 200 cells/μl should provide guidance in making appropriate clinical decisions for the optimal healthcare of this patient demographic. Methods All enrolled patients were selected from 14 prefecture-level general hospitals in Guangxi, China, and were referred to AIDS outpost hospitals for inpatient surgical therapy. A total cohort of 168 adult patients was retrospectively analyzed. Multifactorial and stratified analyses were performed to evaluate the in surgical outcome differences for patients with CD4-CC < 200 cells/μl (N = 43), using those with CD4-CC ≥ 200 cells/μl (N = 125) as controls. Results Poor incisional healing was used as the primary outcome indicator, and postoperative complications were used as the secondary outcome indicator. In the patient group with CD4-CC < 200 cells/μl, the risk of surgical complications was significantly increased (OR 2.379; 95% CI [1.049–5.394]) after adjustment. Adjusted stratified analysis of the CD4-CC < 200 cells/μl group revealed that individuals over 60 years (OR 27.504; 95% CI [2.297–329.317]) with erythrocyte counts below 4.00/ml for males or 3.50/ml for females (OR 3.353; 95% CI [1.079–10.419]) had a significantly higher risk of postoperative complications; this finding was statistically different from the control (CD4 ≥ 200 cells/μl) group. However, there was no significant difference between the two groups regarding the risk of poorly healed incision outcomes. Conclusions Preliminary findings suggest that a serum CD4-CC < 200 cells/μl is not a definitive contraindication for surgical therapy and that baseline and surgical characteristics may help predict surgical outcomes in these patients. Further studies are needed to confirm these findings.

Using data from the 2012 consumer finance survey in China, we extend the literature on household finance by examining the effects of both financial literacy and housing value on household financial market participation, the role of which has been examined separately in the existing literature. The results show that financial literacy significantly improves the probability of household financial market participation, while the housing value has an obvious “crowding-out effect” on household financial market participation in urban China. Further research finds that the role of financial literacy in household financial market participation in households with a low housing value is stronger than that in households with a high housing value. Furthermore, the study of the regional differences shows that among households with a high housing value, financial literacy plays a more significant role in household bond market participation in less-developed cities. Among households with a low housing value, improvement in financial literacy plays a more significant role in household fund market participation in less-developed cities and under-developed cities. Our findings remain robust after alleviating potential bias due to endogenous problems by applying the instrumental variable (IV) method and propensity score matching (PSM) method. Finally, the paper proposes corresponding policy recommendations.

Single-phase five-level transformer-less inverter has been widely used in photovoltaic (PV) applications because of low total harmonic distortion (THD) and excellent output quality. However, a serious problem for transformer-less inverters is the leakage current issue which will lead to safety problems. This paper proposes a single-phase five-level transformer-less inverter to eliminate the leakage current. The circuit consists of eleven active switches and can keep the common mode voltage half of the DC bus voltage. The voltages of flying capacitors are balanced within one switching cycle through selecting the proper switching states. The mechanism of suppressing the leakage current is analyzed in detail with operational modes and modulation strategy. A 1 kW single-phase five-level inverter prototype is built to verify the validity and flexibility of the proposed topology and modulation.

Aquatic products are favored by people all over the world, but the potential quality and safety issues cannot be ignored. To determine the risk of veterinary drug residues in aquatic products in the Yangtze River Delta, this study used geographic information system method to analyze Chinese veterinary drugs in aquatic products in Shanghai, Jiangsu, Zhejiang, and Anhui (Yangtze River Delta Urban Agglomerations) from 2017 to 2019. A study of the spatial distribution pattern, hot spot detection and analysis, and spatiotemporal cluster analysis of the residual excess rate and detection rate showed a random spatial distribution in the overall excess rate and detection rate of veterinary drug residues in aquatic products from 2017 to 2019. The results of hot spot analysis and spatiotemporal cluster analysis showed that the rate of detection of veterinary drug residues and the rate of detection of residues in excess of regulatory standards were clustered. This study provides a scientific basis for food safety evaluation and risk management suggestions. HIGHLIGHTS

Clear cell renal cell carcinoma (ccRCC), the most common subtype, accounts for approximately 80% of all RCC cases. ccRCC patients typically present with an advanced stage at the time of diagnosis resulting in a poor patient prognosis. The present study aimed to identify novel potential microRNAs (miRNAs or miRs) in peripheral blood as biomarkers for the detection of ccRCC. Candidate miRNAs were selected through integrated analysis of the Gene Expression Omnibus (GEO) database, The Cancer Genome Atlas (TCGA) database, and from clinical samples. The expression levels of miRNAs were quantified using reverse transcription-quantitative PCR. Receiver operating characteristic (ROC) curve analysis was used to explore the diagnostic values of the miRNAs. Bioinformatic analysis of candidate miRNAs was conducted by using the STRING database. After an integrated analysis of the GEO and TCGA databases, four miRNAs were found to be consistently dysregulated in ccRCC tissues. Then, their expression levels in serum and diagnostic utilities were further explored. We discovered that serum miR-508-3p and miR-885-5p were significantly dysregulated in ccRCC patients with marked diagnostic values. The area under the ROC curve (AUC) of serum miR-508-3p and miR-885-5p was 0.80 (95% CI, 0.73–0.87) and 0.87 (95% CI, 0.79–0.95), respectively. Functional enrichment analysis revealed that both miR-508-3p and miR-885-5p were closely associated with cellular metabolic processes. In conclusion, serum miR-508-3p and miR-885-5p are novel potential biomarkers for the diagnosis of ccRCC.

Objective To compare the outcomes of patients with non-traumatic cardiac arrest (CA) who received early versus late mechanical cardiopulmonary resuscitation (CPR) with the Lund University Cardiac Assist System (LUCAS) device in the emergency department (ED). Methods This was a retrospective observational study in the ED of a single medical center performed from May 2018 to December 2019; 68 patients with CA were eligible. We grouped the patients according to the time to initiating LUCAS use after CA into an early group (≤4 minutes) and late group (>4 minutes). Results The rate of return of spontaneous circulation (ROSC) was higher in the early group vs the late group (69.2% vs 52.4%, respectively). The 4-hour survival rate was significantly higher in the early group vs the late group (83.3% vs 45.5%, respectively), and CPR duration was significantly shorter in the early group (23.3 ± 12.5 vs 31.1 ± 14.8 minutes, respectively). Conclusion Early mechanical CPR can improve the success of achieving ROSC and the 4-hour survival rate in patients with non-traumatic CA in the ED, considering that more benefits were observed in patients who received early vs late LUCAS device therapy.

Noise-reduction seats have been successfully used in concert halls, theaters, and other places that reduce noise. In this study, a new noise-reduction seat design was proposed for high-speed trains, which have unique interior noise spectral characteristics. First, before the noise-reduction seat models were fabricated, the parameters of high-performance sound-absorbing materials and perforated plates were selected by conducting a standing-wave tube test. The sound-absorption effects of the noise-reduction seats and normal seats were investigated and compared in a reverberation chamber. Test results showed that, compared with normal seats, the noise-reduction seats obtained a significantly improved sound-absorption coefficient in the entire frequency band. Furthermore, the test results were used to establish a simulation model for calculation, and the simulation results proved that the noise-reduction seats substantially reduced the noise in an entire train car. Finally, the noise-reduction seats were fabricated and installed in a full train car of an actual high-speed train. The test results showed that, compared with the normal seats, the noise-reduction seats decreased the noise level at a standard point in the passenger car by 1.5 dB. Therefore, the noise-reduction seats are effective in noise reduction.

Identifying lncRNA-protein Interactions (LPIs) is vital to understanding various key biological processes. Wet experiments found a few LPIs, but experimental methods are costly and time-consuming. Therefore, computational methods are increasingly exploited to capture LPI candidates. We introduced relevant data repositories, focused on two types of LPI prediction models: network-based methods and machine learning-based methods. Machine learning-based methods contain matrix factorization-based techniques and ensemble learning-based techniques. To detect the performance of computational methods, we compared parts of LPI prediction models on Leave-One-Out cross validation (LOOCV) and five-fold cross validation. The results show that SFPEL-LPI obtained the best performance of AUC. Although computational models have efficiently unraveled some LPI candidates, there are many limitations involved. We discussed future directions to further boost LPI predictive performance.

Purpose: The majority of patients with prostate cancer who are treated with androgen-deprivation therapy (ADT) will eventually develop fatal metastatic castration-resistant prostate cancer (mCRPC). Currently, there are no effective durable therapies for patients with mCRPC. High expression of galectin-1 (Gal-1) is associated with prostate cancer progression and poor clinical outcome. The role of Gal-1 in tumor progression is largely unknown. Here, we characterized Gal-1 functions and evaluated the therapeutic effects of a newly developed Gal-1 inhibitor, LLS30, in mCRPC.Experimental Design: Cell viability, colony formation, migration, and invasion assays were performed to examine the effects of inhibition of Gal-1 in CRPC cells. We used two human CRPC xenograft models to assess growth-inhibitory effects of LLS30. Genome-wide gene expression analysis was conducted to elucidate the effects of LLS30 on metastatic PC3 cells.Results: Gal-1 was highly expressed in CRPC cells, but not in androgen-sensitive cells. Gal-1 knockdown significantly inhibited CRPC cells' growth, anchorage-independent growth, migration, and invasion through the suppression of androgen receptor (AR) and Akt signaling. LLS30 targets Gal-1 as an allosteric inhibitor and decreases Gal-1–binding affinity to its binding partners. LLS30 showed in vivo efficacy in both AR-positive and AR-negative xenograft models. LLS30 not only can potentiate the antitumor effect of docetaxel to cause complete regression of tumors, but can also effectively inhibit the invasion and metastasis of prostate cancer cells in vivo.Conclusions: Our study provides evidence that Gal-1 is an important target for mCRPC therapy, and LLS30 is a promising small-molecule compound that can potentially overcome mCRPC. Clin Cancer Res; 24(17); 4319–31. ©2018 AACR.

This study developed the potential regulation capacity (PRC) and actual regulation capacity (ARC) to characterize the flood regulation function of river systems in the delta plains. Spatial autocorrelation and the grey relational analysis were then employed to investigate the spatial-temporal change of the flood regulation function in the urbanization process, of which the results revealed its spatial coupling and quantitative relation with the urbanization process and river systems changes in the Taihu Plain. The results indicated that: (1) the PRC exhibited a 20.3%-decrease during the 1960s to the 2010s, though its change exhibited significant structural and hierarchical differences. The global distributions of the PRCs all presented insignificant clustered characteristics, and the local distribution of smaller PRC regions with a high flood risk was stable; (2) the ARC exhibited a 33.2%-reduction in the recent 50years, and its decrement also exhibited an accelerating trend. The global ARC distribution changed from significant clusters to insignificant aggregations, and the local distribution range of the smaller ARC regions with a high flood risk gradually increased; (3) the spatial coupling degree between the change in the PRC and the urbanization process was greater than that between the change in the ARC and the urbanization process, and the effect of urbanization on the change in the PRC was also larger than the change in the ARC; (4) the spatial coupling degree between the changes in the ARC and the river systems was greater than that between the changes in the PRC and the river systems, though the impacts of the river systems changes on the change in the PRC were larger than that on the change in the ARC. Therefore, the developed indicators based on limited and available information can serve as references for planning effective flood control strategies in the delta plains.

This review presents the current technical statuses of European high-speed bogie technology and related infrastructure, in which the concepts and design solutions associated with the high-speed rolling stocks and railway are summarised. Regarding the high-speed railway infrastructure conditions, the vehicle gauges, track gauge, rail profiles, and associated inclinations for various countries and rail networks are discussed briefly, as well as the curve arrangements and track irregularities. Then four typical and widely used high-speed bogies are introduced with their design principles and solutions are discussed, in which the advantages and disadvantages of various bogie frame types, bearings, wheelset steering arrangements, and primary/secondary suspensions are thoroughly analysed. Furthermore, the brake system commonly used in European railway networks and the on-board diagnostic systems used to ensure safe operation are also discussed concerning their applicability, versatility and reliability. A general understanding of the technical specification for interoperability (TSI) is also included in this investigation.

For effective utilization of a large amount of vibration data which are collected during the normal operation of train rolling bearing, this paper puts forward a new method for rolling bearing degradation condition assessment which combines the local mean decomposition (LMD) and support vector data description (SVDD). LMD is used to decompose the vibration signal, after the decomposition, we extract feature vector from three points of view: time–frequency, energy and entropy, statistical characteristic value. Principal component analysis can help to reduce dimension. Therefore, we just need to collect the data when rolling bearing normally operates to establish the evaluation model, and then realize the rolling bearing degradation status quantitative evaluation.

At present, the international high-speed rail on clean and green and intelligent technology received unprecedented attention, especially the integration of security technology has become a core technology development trends. First, this paper does reliability analysis from the high-speed train system. Statistics of the subsystems of the failure rate is done. Then important subsystems bogie system reliability is analyzed combining with the maintenance on the high-speed train system reliability analysis. The parts distribution functions and associated parameters are fitted on software. Finally, we set up truck event tree model and reliability analysis of bogie system.

Magnetic resonance imaging is a new imaging technology based on the hydrogen’s magnetic resonance feature. Gradient module should have high calculation speed and accuracy to complete massive computation work including rotation transform, eddy compensation and shimming in a very short time. We make a deep exploration into the gradient module from its function, real-time and accuracy requirements. Then, we propose and realize a novel gradient module based on high performance DSP. Experiments indicate that the gradient module we designed satisfies the function, real-time and accuracy requirements. It provides a practical gradient module solution for the development of digital Spectrometer.

In this paper, a measurement model of particle filter based on multiple cues fusion is presented. Firstly, color histogram and motion information histogram are built respectively via extracting color information and movement information, and then a weighted linear model is built as the measurement model. In addition, the center-around method is used to decide the object outline definition which is adopted to compute the weight in the weighted linear model. The parameter sigma in Gaussian function is acquired by using adaptive inverse estimation. Lastly, a mass of experiments show the presented method is effective.

Mesenchymal stem cell (MSC) therapy shows considerable promise for the treatment of myocardial infarction (MI). However, the inefficient migration and homing of MSCs after systemic infusion have limited their therapeutic applications. Ultrasound-targeted microbubble destruction (UTMD) has proven to be promising to improve the homing of MSCs to the ischemic myocardium, but the concrete mechanism remains unclear. We hypothesize that UTMD promotes MSC homing by upregulating SDF-1/CXCR4, and this study was aimed at exploring this potential mechanism. We analyzed SDF-1/CXCR4 expression after UTMD treatment in vitro and in vivo and counted the number of homing MSCs in MI areas. The in vitro results demonstrated that UTMD not only led to elevated secretion of SDF-1 but also resulted in an increased proportion of MSCs that expressed surface CXCR4. The in vivo findings show an increase in the number of homing MSCs and higher expression of SDF-1/CXCR4 in the UTMD combined with MSCs infusion group compared to other groups. In conclusion, UTMD can increase SDF-1 expression in the ischemic myocardium and upregulate the expression of surface CXCR4 on MSCs, which provides a molecular mechanism for the homing of MSCs assisted by UTMD via SDF-1/CXCR4 axis.

Meeting the deadline requirement for the application flow is always a challenge in data centre. Aiming at this problem, many transmission control protocol (TCP) variants are proposed and most of them focus on improving the congestion avoidance phase while rarely considering the slow-start. This paper presents an improved TCP slow-start mechanism, which uses large initial windows (LIW) to help more flows to be finished before their deadlines and does not increase the network congestion meanwhile. The simulation results show that LIW can greatly enhance the meeting deadline ratio of flows involved in web searching and data mining application services which are common in data centres. Moreover, LIW can be easily deployed with rarely modifying the TCP stack.

In order to lower the voltage stress on power devices, the three-level topologies are widely used in high voltage converters. In the topologies a flying capacitor is added to achieve true ZVS under phase shift control. But the ZVS three-level converter will run abnormally at light load if the flying capacitor is added. The main issue is the charge unbalance across the flying capacitor. Due to the unbalance, the voltage stress on the switches of lagging leg becomes high so much as 500 V under 800 V bus condition. This issue will also appear under open voltage loop condition (this condition may occur in dynamic load). Aiming at this issue, the reason of charge unbalance of the flying capacitor is firstly analyzed under the light load and open voltage loop in this paper. An experiment is implemented for testifying the analysis. A novel method is presented for this issue. This method not only effectively balances the charge of the capacitor but also is lossless.

ion implants. A dielectric anti-reflective coating (ARC) is deposited over the hard-maskto prevent parasitic reflections and achieve low reflectivity. The dielectric ARC filmconsists of three layers with varying silicon concentration and with different index ofrefraction and extinction coefficient. These layers match the optical properties of theresist to the dielectric ARC. The gate features are finally patterned with deep-UV resistand achieve tight 0.25 im design rules. A distribution of Leff for 10 lots is shown inFig. 2. Hot carrier considerations are quite different for the two supply voltage grades.Hence an extra photolithography is necessary for the NMOS lightly doped drain (LDD)region. Patterned phosphorus LDD implants are used for the 3.3 V NMOS device, whilearsenic implants are used for the 2.5 V NMOS transistor. The 2.5 V and 3.3 V PMOStransistors share the same BF2 LDD implant. TEOS spacers are formed and source-drain(SID)

This paper describes investigations of GaAs solar cells grown on (100) GaP by MOCVD. This work is being carried out as part of an effort to fabricate GaAs and other III-V cells from film structures grown on silicon substrates coated with a pseudomorphic GaP film. Heteroepitaxial growth of GaAs on GaP is interesting regardless of the potential application to GaP-coated Si. Problems associated with the removal of SiO/sup 2/ from Si substrates, and possible regrowth of SiO/sup 2/ prior to growth of GaAs, and difficulties caused by a large mismatch in thermal expansion coefficients do not exist when growing GaAs on GaP. The lattice mismatch between GaAs and GaP is 3.57%, similar to that between Si and GaAs (3.93%). Thus, one knows that dislocations in the heteroepitaxial GaAs film structures grown on GaP are primarily a result of lattice mismatch. After growing a P/N cell structure, arrays of 0.109 cm/sup 2/ cells are fabricated on the heteroepitaxial film structure with the use of photolithography. To date, the best cell performance has been an active area efficiency of 10.2%, with an active area J/sub SC/=18.1 mA/cm/sup 2/, FF=0.745 and V/sub OC/=757 mV.