A Controllable LCL-T Resonant AC/DC Converter for High Frequency Power Distribution Systems

Zeng, Jun,Li, Xuesheng,Liu, Junfeng The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.4

High frequency alternating current (HFAC) has been widely used in a wide range of power distribution systems (PDS) due to its superior performance. A high frequency AC/DC converter plays the role of converting HFAC voltage to DC voltage. In this paper, a new LCL-T resonant AC/DC converter has been proposed, and an easier control method based on input voltage comparison is presented, without the complicated calculation of the zero-crossing point. Both a low distortion and near-to-unity power factor can be achieved by the proposed resonant converter and control strategy. The operational principle and steady-state analysis are given for the proposed resonant converter. A simulation model and experimental prototype are implemented with an operation frequency of 25kHz and a rated power of 20W. The simulation and experimental results verify the accuracy of the analysis and the excellent performance of the proposed topology.

A Controllable LCL-T Resonant AC/DC Converter for High Frequency Power Distribution Systems

Jun Zeng,Xuesheng Li,Junfeng Liu 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.4

High frequency alternating current (HFAC) has been widely used in a wide range of power distribution systems (PDS) due to its superior performance. A high frequency AC/DC converter plays the role of converting HFAC voltage to DC voltage. In this paper, a new LCL-T resonant AC/DC converter has been proposed, and an easier control method based on input voltage comparison is presented, without the complicated calculation of the zero-crossing point. Both a low distortion and near-to-unity power factor can be achieved by the proposed resonant converter and control strategy. The operational principle and steady-state analysis are given for the proposed resonant converter. A simulation model and experimental prototype are implemented with an operation frequency of 25kHz and a rated power of 20W. The simulation and experimental results verify the accuracy of the analysis and the excellent performance of the proposed topology.

A comparison of the fracture resistances of endodontically treated mandibular premolars restored with endocrowns and glass fiber postcore retained conventional crowns

Jing Guo,Zhiming Wang,Xuesheng Li,Chaoyang Sun,Erdong Gao,Hongbo Li 대한치과보철학회 2016 The Journal of Advanced Prosthodontics Vol.8 No.6

PURPOSE This in-vitro study aimed to evaluate the fracture resistances and failure modes of endodontically treated mandibular premolars restored with endocrowns and conventional post-core retained crowns. MATERIALS AND METHODS Thirty mandibular premolars were assigned into three groups (n=10): GI, intact teeth; GE, teeth with endocrowns; GC, teeth with conventional post-core supported crowns. Except for the teeth in group GI, all specimens were cut to 1.5 mm above the cementoenamel junction and endodontically treated. Both endocrowns and conventional crowns were fabricated from lithium-disilicate blocks using a CEREC 3D CAD/CAM unit. All specimens were subjected to thermocycling and then to 45° oblique compressive load until fracture occurred. The fracture resistance and failure mode of each specimen were recorded. Data were analyzed with one-way ANOVA and LSD Post Hoc Test (α=.05). RESULTS The fracture resistances of GE and GC were significantly lower than that of GI (P<.01), while no significant difference was found between GE and GC (P=.702). As of the failure mode, most of the specimens in GE and GC were unfavorable while a higher occurrence of favorable failure mode was presented in GI. CONCLUSION For the restoration of mandibular premolar, endocrown shows no advantage in fracture resistance when compared with the conventional method. Both of the two methods cannot rehabilitate endodontically treated teeth with the same fracture resistances that intact mandibular premolars have.

A comparison of the fracture resistances of endodontically treated mandibular premolars restored with endocrowns and glass fiber post-core retained conventional crowns

Guo, Jing,Wang, Zhiming,Li, Xuesheng,Sun, Chaoyang,Gao, Erdong,Li, Hongbo The Korean Academy of Prosthodonitics 2016 The Journal of Advanced Prosthodontics Vol.8 No.6

PURPOSE. This in-vitro study aimed to evaluate the fracture resistances and failure modes of endodontically treated mandibular premolars restored with endocrowns and conventional post-core retained crowns. MATERIALS AND METHODS. Thirty mandibular premolars were assigned into three groups (n=10): GI, intact teeth; GE, teeth with endocrowns; GC, teeth with conventional post-core supported crowns. Except for the teeth in group GI, all specimens were cut to 1.5 mm above the cementoenamel junction and endodontically treated. Both endocrowns and conventional crowns were fabricated from lithium-disilicate blocks using a CEREC 3D CAD/CAM unit. All specimens were subjected to thermocycling and then to $45^{\circ}$ oblique compressive load until fracture occurred. The fracture resistance and failure mode of each specimen were recorded. Data were analyzed with one-way ANOVA and LSD Post Hoc Test (${\alpha}=.05$). RESULTS. The fracture resistances of GE and GC were significantly lower than that of GI (P<.01), while no significant difference was found between GE and GC (P=.702). As of the failure mode, most of the specimens in GE and GC were unfavorable while a higher occurrence of favorable failure mode was presented in GI. CONCLUSION. For the restoration of mandibular premolar, endocrown shows no advantage in fracture resistance when compared with the conventional method. Both of the two methods cannot rehabilitate endodontically treated teeth with the same fracture resistances that intact mandibular premolars have.

Induced Intermediate Mesoderm Combined with Decellularized Kidney Scaffolds for Functional Engineering Kidney

Jianye Zhang,Kailin Li,Feng Kong,Chao Sun,Denglu Zhang,Xin Yu,Xuesheng Wang,Xian Li,Tongyan Liu,Guangfeng Shao,Yong Guan,Shengtian Zhao 한국조직공학과 재생의학회 2019 조직공학과 재생의학 Vol.16 No.6

BACKGROUND: Chronic kidney disease is a severe threat to human health with no ideal treatment strategy. Mature mammalian kidneys have a fixed number of nephrons, and regeneration is difficult once they are damaged. For this reason, developing an efficient approach to achieve kidney regeneration is necessary. The technology of the combination of decellularized kidney scaffolds with stem cells has emerged as a new strategy; however, in previous studies, the differentiation of stem cells in decellularized scaffolds was insufficient for functional kidney regeneration, and many problems remain. METHODS: We used 0.5% sodium dodecyl sulfate (SDS) to produce rat kidney decellularized scaffolds, and induce adipose-derived stem cells (ADSCs) into intermediate mesoderm by adding Wnt agonist CHIR99021 and FGF9 in vitro. The characteristics of decellularized scaffolds and intermediate mesoderm induced from adipose–derived stem cells were identified. The scaffolds were recellularized with ADSCs and intermediate mesoderm cells through the renal artery and ureter. After cocultured for 10 days, cells adhesion and differentiation was evaluated. RESULTS: Intermediate mesoderm cells were successfully induced from ADSCs and identified by immunofluorescence and Western blotting assays (OSR1 ? , PAX2 ?). Immunofluorescence showed that intermediate mesoderm cells differentiated into tubular-like (E-CAD ? , GATA3 ?) and podocyte-like (WT1 ?) cells with higher differentiation efficiency than ADSCs in the decellularized scaffolds. Comparatively, this phenomenon was not observed in induced intermediate mesoderm cells cultured in vitro. CONCLUSION: In this study, we demonstrated that intermediate mesoderm cells could be induced from ADSCs and that they could differentiate well after cocultured with decellularized scaffolds.

Effects of Intravesical Electrical Stimulation on Urinary Adenosine Triphosphate and Nitric Oxide in Rats With Detrusor Underactivity Induced By Bilateral Pelvic Nerve Crush Injury: The Possible Underlying Mechanism

Han Deng,Limin Liao,Xing Li,Qinggang Liu,Xuesheng Wang,Zhonghan Zhou 대한배뇨장애요실금학회 2022 International Neurourology Journal Vol.26 No.4

Purpose: To explore the effect of intravesical electrical stimulation (IVES) on urinary adenosine triphosphate (ATP) and nitric oxide (NO) in rats with detrusor underactivity (DU) induced by bilateral pelvic nerve crush (bPNC), and to determine the underlying peripheral mechanism. Methods: Twenty-four female Sprague-Dawley rats were equally divided into 3 groups: sham; bPNC; and IVES. Rats in the IVES group began to receive IVES treatment 10 days after bPNC (20 minutes per day for 14 consecutive days). After the 14th IVES, rat urine was collected and cystometry was performed. The serum creatinine, blood urea nitrogen, and urinary ATP and NO levels were measured, and a routine urinalysis was performed. Results: The maximum cystometric capacity (MCC), maximum changes in bladder pressure during filling (∆FP), and postvoid residual urine (PVR) in the IVES group were significantly lower than the bPNC group, and the maximum changes in bladder pressure during voiding (∆VP) was significantly higher than the bPNC group. Compared with the sham group, the MCC, ∆FP and PVR were significantly increased, and the maximum voiding pressure (MVP) and ∆VP were significantly decreased in the bPNC group. After bPNC, urinary ATP was significantly decreased, and urinary NO was significantly increased. In IVES-treated rats, urinary ATP was significantly higher than the bPNC group, and NO was significantly lower than the bPNC group. In addition, the ATP-to-NO ratio of the rats in the bPNC group was significantly lower than the sham and IVES groups. Correlation analysis showed that the ATP and NO were not correlated with the MCC, ∆FP, MVP, ∆VP, and PVR. Conclusions: Promoting the release of urothelial ATP and inhibiting the release of urothelial NO may be one of the peripheral mechanisms underlying IVES in the treatment of DU. Specifically, IVES may shift the balance between excitation and inhibition toward excitation