Nasal Nitric Oxide Is Correlated With Nasal Patency and Nasal Symptoms

Lei Ren,Wei Zhang,Yuan Zhang,Luo Zhang 대한천식알레르기학회 2019 Allergy, Asthma & Immunology Research Vol.11 No.3

Purpose: Nitric oxide (NO) is an important endogenous mediator in both upper and lower respiratory systems. The purpose of the present study was to extract nasal NO (nNO) normal range of Chinese adults and the internal influencing factors. The differences in nNO levels between rhinitis and asymptomatic atopic subjects, and the diagnostic value of nNO in allergic rhinitis (AR) were further investigated. Methods: One thousand adults were recruited from the general public. Participants were divided into different subgroups according to the questionnaires and skin prick tests. In all of these subjects, nNO, fractional exhaled NO (FeNO) and nasal airflow resistance were measured. The normal ranges of nNO and FeNO, the differences between subgroups, and the correlations between NO (nNO and FeNO) and other internal factors were analyzed. Results: Both nNO and FeNO levels were significantly higher in AR patients than in healthy and asymptomatic atopic subjects. The nNO levels were significantly lower in asymptomatic atopic subjects than in normal adults. FeNO levels were significantly higher in non-AR patients than in the healthy and asymptomatic atopic adults. The cutoff value of nNO for the diagnosis of AR was 117.5 ppb (sensitivity, 50.9%; specificity, 63.9%). The nNO levels were correlated with FeNO levels, total nasal resistance measured at 75Pa, nasal volume within 0–7 cm from the anterior nares (V0-7cm) and nasal symptom visual analogue scale (VAS) scores, while the FeNO levels were correlated with age, height, weight, body surface area, nasal volume of V0-7cm and the nasal symptom VAS score. Conclusions: The nNO level can be significantly different between healthy and AR patients and may be significantly correlated with nasal symptoms and nasal patency of rhinitis patients. However, the clinical value of nNO is still in the exploration stage.

Ringing Frequency Extraction Method Based on EMD and FFT for Health Monitoring of Power Transistors

Ren, Lei,Gong, Chunying The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1

Condition monitoring has been recognized as an effective and low-cost method to enhance the reliability and improve the maintainability of power electronic converters. In power electronic converters, high-frequency oscillation occurs during the switching transients of power transistors, which is known as ringing. The ringing frequency mainly depends on the values of the parasitic capacitance and stray inductance in the oscillation loop. Although circuit stray inductance is an important factor that leads to the ringing, it does not change with transistor aging. A shift in either the inside inductance or junction capacitance is an important failure precursor for power transistors. Therefore, ringing frequency can be used to monitor the health of power transistors. However, the switching actions of power transistors usually result in a dynamic behavior that can generate oscillation signals mixed with background noise, which makes it hard to directly extract the ringing frequency. A frequency extraction method based on empirical mode decomposition (EMD) and Fast Fourier transformation (FFT) is proposed in this paper. The proposed method is simple and has a high precision. Simulation results are given to verify the ringing analysis and experimental results are given to verify the effectiveness of the proposed method.

Ringing Frequency Extraction Method Based on EMD and FFT for Health Monitoring of Power Transistors

Lei Ren,Chunying Gong 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1

Condition monitoring has been recognized as an effective and low-cost method to enhance the reliability and improve themaintainability of power electronic converters. In power electronic converters, high-frequency oscillation occurs during theswitching transients of power transistors, which is known as ringing. The ringing frequency mainly depends on the values of theparasitic capacitance and stray inductance in the oscillation loop. Although circuit stray inductance is an important factor thatleads to the ringing, it does not change with transistor aging. A shift in either the inside inductance or junction capacitance is animportant failure precursor for power transistors. Therefore, ringing frequency can be used to monitor the health of powertransistors. However, the switching actions of power transistors usually result in a dynamic behavior that can generate oscillationsignals mixed with background noise, which makes it hard to directly extract the ringing frequency. A frequency extractionmethod based on empirical mode decomposition (EMD) and Fast Fourier transformation (FFT) is proposed in this paper. Theproposed method is simple and has a high precision. Simulation results are given to verify the ringing analysis and experimentalresults are given to verify the effectiveness of the proposed method.

Fe₃O₄ magnetic nanoparticles provide a novel alternative strategy for Staphylococcus aureus bone infection

Youliang, Ren,Jin, Yang,Jinghui, Zhang,Xiao, Yang,Lei, Shi,Dajing, Guo,Yuanyi, Zheng,Haitao, Ran,Zhongliang, Deng,Lei, Chu Techno-Press 2022 Advances in nano research Vol.13 No.6

Due to its biofilm formation and colonization of the osteocyte-lacuno canalicular network (OLCN), Staphylococcus aureus (S.aureus) implant-associated bone infection (SIABI) is difficult to cure thoroughly, and may occur recurrently subsequently after a long period dormant. It is essential to explore an alternative therapeutic strategy that can eradicate the pathogens in the infected foci. To address this, the polymethylmethacrylate (PMMA) bone cement and Fe3O4 nanoparticles compound cylinder were developed as implants based on their size and mechanical properties for the alternative magnetic field (AMF) induced thermal ablation, The PMMA mixed with optimized 2% Fe₃O₄ nanoparticles showed an excellent antibacterial efficacy in vitro. It was evaluated by the CFU, CT scan and histopathological staining on a rabbit 1-stage transtibial screw model. The results showed that on week 7, the CFU of infected soft tissue and implants, and the white blood cells (WBCs) of the PMMA+2% Fe₃O₄+AMF group decreased significantly from their controls (p<0.05). PMMA+2% Fe₃O₄+AMF group did not observe bone resorption, periosteal reaction, and infectious reactive bone formation by CT images. Further histopathological H&E and Gram Staining confirmed there was no obvious inflammatory cell infiltration, neither pathogens residue nor noticeably burn damage around the infected screw channel in the PMMA+2% Fe₃O₄+AMF group. Further investigation of nanoparticle distributions in bone marrow medullary and vital organs of heart, liver, spleen, lung, and kidney. There were no significantly extra Fe₃O₄ nanoparticles were observed in the medullary cavity and all vital organs either. In the current study, PMMA+2% Fe₃O₄+AMF shows promising therapeutic potential for SIABI by providing excellent mechanical support, and promising efficacy of eradicating the residual pathogenic bacteria in bone infected lesions.

Enhanced electrical conductivity of pitch-derived carbon via graphene template effects for high electrically conductive composites

Zhiping Lei,Yazhou Li,Zhao Lei,Xue Yang,Jingchong Yan,Zhanku Li,Hengfu Shui,Shibiao Ren,Zhicai Wang,Ying Kong,Shigang Kang 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.117 No.-

Large-scale preparation of cheap and high-performance carbonaceous materials is in urgent need due tothe huge demand of carbonaceous materials-organic binder composites for Joule heating. Here, carbonbasedelectrothermal composites with high electrical conductivity were fabricated by adjusting the morphologyand structure of pitch-based carbonaceous materials (PC) through the use of graphene asstructure-directing agent to tune the orientation and carbonization of coal pitch. It is demonstrated thatthe addition of graphene can effectively promote the formation of graphitized carbon, increase the contentof sp2C, reduce defective carbon and increase the graphite interlayer spacing. 1% graphene-added PCPVDFcomposite exhibits 290% increase in the carrier concentration, 190% enhancement in mobility, and67% reduction in the volume resistivity compared to PC-PVDF composite. Molecular simulations elucidatethat the graphene edges favor pitch carbonization and improve the orientation factor and energy gap ofcarbon materials. This study provides clues for design of low-cost pitch-derived carbon materials-bindercomposites.

3D Printing of Bioinspired Structural Materials with Fibers Induced by Doctor Blading Process

Luquan Ren,Bingqian Li,Zhengyi Song,Qingping Liu,Lei Ren,Xueli Zhou 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.6 No.1

Fiber is a crucial element in biological micro-structural materials. Replication of fiber-reinforced composites with analogous architectures of their natural counterparts has caused widespread academic concern. Recent researches indicate 3D printing technology has the potential to produce biomimetic structural materials. The aim of this study is to develop a process to fabricate fiber-reinforced composites with ordered yet spatially tunable fiber arrangement. Specifically, we present a method to align fibers during the 3D printing of fiber-reinforced composites. A modified slurry-based stereolithography process was developed, and the fibers in the fiber–resin mixture were aligned by Shear force produced during the spreading of slurry. We investigated the influence of relative factors on fiber orientation, and two models were used to uncover the internal mechanism. By controlling the speed and the direction of the moving blade, the patterns that fibers were arranged can be freely programmed. Therefore, we have extracted bioinspired sinusoidal and zigzag design motifs to analyze their mechanical properties compared with non-bioinspired motifs. The proposed method is relatively material agnostic, more efficient and more facile. It thus provides a promising route to fabricate fiber-reinforced composites, and has potential to be adopted in biological structures researches and industrial applications.

Oncoplastic Breast Conserving Surgery with Nipple-areolar Preservation for Centrally Located Breast Cancer: a Retrospective Cohort Study

Ren, Zhao-Jun,Li, Xiu-Juan,Xu, Xin-Yu,Xia, Lei,Tang, Jin-Hai Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.12

A compariosn was made of survival outcomes of oncoplastic breast conserving therapy (oBCT) with nipple-areolar (NAC) preservation in women with centrally located breast cancer (CLBC) undergoing modified radical mastectomy (MRM) in China in a matched retrospective cohort study. We used a database including patients who received oBCT (n=91) or MRM (n=182) from 2003 to 2013 in our hospital. Matching was conducted according to five variables: age at diagnosis, axillary lymph node status, hormone receptor status, human epidermal growth factor-like receptor 2 status (HER-2) and tumor stage. The match ratio was 1:2. Median follow-up times for the oBCT and MRM groups were 83 and 81 months, respectively. There were no significant differences in 87-month overall, local, or distant recurrence-free survival between patients with oBCT and MRM (89%vs.90%; 93%vs.95%; 91%vs.92%;). For appropriate breast cancer patients, oBCT for CLBC is oncologically safe, oncoplastic techniques improving cosmetic outcomes.

An Improved One Cycle Control for Active Power Filters under Non-Ideal Voltage Conditions

Lei Wang,Chunguang Ren,Yu Yang,Xiaoqing Han,Peng Wang 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

The one cycle control (OCC) scheme for active power filters (APFs) has shown excellent harmonic suppression and implementation simplicity. However, its real world application is limited because the non-ideal supply voltage for APFs can influence its performance so that the source currents are still distorted after compensation. This paper proposes a modified one cycle control (MOCC) scheme to improve the performance of three-phase shunt APFs under non-ideal supply voltage conditions. In this paper a detailed mathematical derivation has been presented and the key control law of the MOCC has been developed for adaption to the non-ideal supply voltages, following the control philosophy of simplicity. A relatively simple sequence filter is introduced to extract the harmonic components of supply voltages. The modified scheme can be easily implemented. The proposed control strategy has excellent performance and a 5kVA APF hardware platform has been implemented to validate the feasibility and performance of the proposed strategy.

Age-dependent Changes of Differential Gene Expression Profile in Backfat Tissue between Hybrids and Parents in Pigs

Ren, ZH.Q.,Xiong, Yuanzhu,Deng, CH.Y.,Zuo, B.,Liu, Y.G.,Lei, M.G. Asian Australasian Association of Animal Productio 2005 Animal Bioscience Vol.18 No.5

Large White, an introduced European pig breed, and Meishan, a Chinese indigenous pig breed, were hybridized directly and reciprocally and a total of 260 pigs, including purebreds, Large White and Meishan, and their hybrids, White${\times}$Meishan (LM) and Meishan${\times}$Large White (ML) pigs, were bred in our laboratory. The mRNA differential display PCR (DD-PCR) was used to detect the age-dependent changes of differential gene expression in backfat tissue between hybrids and parents. Some measures were taken to reduce the false positives in our experiment. Among the total of 2,686 bands obtained, 1,952 bands (about 72.67%) were reproducible and eight patterns (fifteen kinds) of gene expression were observed. The percentage of differentially expressed genes between hybrids and parents is 56.86% at the age of four months and 57.71% at the age of six months. This indicated that the differences of gene expression between hybrids and their parents were very obvious. U-test was used to compare the patterns of gene expression between the age of four and six months, and results showed that bands occurring in only one hybrid and bands displayed in one hybrid and one parent were significantly different at p<0.05, and bands visualized in only two hybrids were significantly different at p<0.01. These indicated that differential gene expression between hybrids and parents changed at different ages.

Source Current Control Strategy of Active Power Filters for Unbalanced Load Compensation in Three-Phase Four-Wire Distribution Networks

Lei Wang,Xiaoqing Han,Runquan Meng,Chunguang Ren,Qi Wang,Baifu Zhang 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.5

This paper proposes a modified control strategy to improve the performance of three-phase four-leg shunt active power filters (APFs) for the compensation of three phase unbalanced loads. Unbalanced current cannot be obtained accurately by a harmonic detector due to the lower frequency. The proposed control strategy eliminates conventional harmonic detectors by directly regulating the source current. Therefore, the computational complexity is greatly reduced and the performance of the APF is improved. A mathematic model has been developed based on the source currents. The corresponding controllers have been designed based on the sinusoidal internal model principle. The proposed control strategy can guarantee excellent compensation performance and stable operation after an extreme disturbance such as a short circuit fault. In addition, the proposed technique can selectively compensate specific harmonics. A 50kVA prototype APF is implemented in the laboratory to validate the feasibility and performance of the proposed control strategy.