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Geng K, Shen C, Wang X, Wang X, Shao W, Wang W, Chen T, Sun H, Xie H. A physiologically-based pharmacokinetic/pharmacodynamic modeling approach for drug-drug-gene interaction evaluation of S-warfarin with fluconazole. CPT Pharmacometrics Syst Pharmacol 2024; 13:853-869. [PMID: 38487942 PMCID: PMC11098157 DOI: 10.1002/psp4.13123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 01/17/2024] [Accepted: 02/07/2024] [Indexed: 05/18/2024] Open
Abstract
Warfarin is a widely used anticoagulant, and its S-enantiomer has higher potency compared to the R-enantiomer. S-warfarin is mainly metabolized by cytochrome P450 (CYP) 2C9, and its pharmacological target is vitamin K epoxide reductase complex subunit 1 (VKORC1). Both CYP2C9 and VKORC1 have genetic polymorphisms, leading to large variations in the pharmacokinetics (PKs) and pharmacodynamics (PDs) of warfarin in the population. This makes dosage management of warfarin difficult, especially in the case of drug-drug interactions (DDIs). This study provides a whole-body physiologically-based pharmacokinetic/PD (PBPK/PD) model of S-warfarin for predicting the effects of drug-drug-gene interactions on S-warfarin PKs and PDs. The PBPK/PD model of S-warfarin was developed in PK-Sim and MoBi. Drug-dependent parameters were obtained from the literature or optimized. Of the 34 S-warfarin plasma concentration-time profiles used, 96% predicted plasma concentrations within twofold range compared to observed data. For S-warfarin plasma concentration-time profiles with CYP2C9 genotype, 364 of 386 predicted plasma concentration values (~94%) fell within the twofold of the observed values. This model was tested in DDI predictions with fluconazole as CYP2C9 perpetrators, with all predicted DDI area under the plasma concentration-time curve to the last measurable timepoint (AUClast) ratio within twofold of the observed values. The anticoagulant effect of S-warfarin was described using an indirect response model, with all predicted international normalized ratio (INR) within twofold of the observed values. This model also incorporates a dose-adjustment method that can be used for dose adjustment and predict INR when warfarin is used in combination with CYP2C9 perpetrators.
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Affiliation(s)
- Kuo Geng
- Anhui Provincial Center for Drug Clinical EvaluationYijishan Hospital of Wannan Medical CollegeWuhuAnhuiChina
- Wannan Medical CollegeWuhuAnhuiChina
| | - Chaozhuang Shen
- Department of Clinical Pharmacy and Pharmacy Administration, West China College of PharmacySichuan UniversityChengduSichuanChina
| | - Xiaohu Wang
- Department of PharmaceuticsChina Pharmaceutical UniversityNanjingChina
| | - Xingwen Wang
- Anhui Provincial Center for Drug Clinical EvaluationYijishan Hospital of Wannan Medical CollegeWuhuAnhuiChina
- Wannan Medical CollegeWuhuAnhuiChina
| | - Wenxin Shao
- Anhui Provincial Center for Drug Clinical EvaluationYijishan Hospital of Wannan Medical CollegeWuhuAnhuiChina
- Wannan Medical CollegeWuhuAnhuiChina
| | - Wenhui Wang
- Anhui Provincial Center for Drug Clinical EvaluationYijishan Hospital of Wannan Medical CollegeWuhuAnhuiChina
- Wannan Medical CollegeWuhuAnhuiChina
| | - Tao Chen
- Anhui Provincial Center for Drug Clinical EvaluationYijishan Hospital of Wannan Medical CollegeWuhuAnhuiChina
- Wannan Medical CollegeWuhuAnhuiChina
| | - Hua Sun
- Anhui Provincial Center for Drug Clinical EvaluationYijishan Hospital of Wannan Medical CollegeWuhuAnhuiChina
| | - Haitang Xie
- Anhui Provincial Center for Drug Clinical EvaluationYijishan Hospital of Wannan Medical CollegeWuhuAnhuiChina
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Wang X, Wang X, Yao H, Shen C, Geng K, Xie H. A comprehensive review on Schisandrin and its pharmacological features. Naunyn Schmiedebergs Arch Pharmacol 2024; 397:783-794. [PMID: 37658213 DOI: 10.1007/s00210-023-02687-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 08/22/2023] [Indexed: 09/03/2023]
Abstract
Schisandrin stands as one of the primary active compounds within the widely used traditional medicinal plant Schisandra chinensis (Turcz.) Baill. This compound exhibits sedative, hypnotic, anti-aging, antioxidant, and immunomodulatory properties, showcasing its effectiveness across various liver diseases while maintaining a favorable safety profile. However, the bioavailability of schisandrin is largely affected by hepatic and intestinal first-pass metabolism, which limits the clinical efficacy of schisandrin. In this paper, we review the various pharmacological effects and related mechanisms of schisandrin, in order to provide reference for subsequent drug research and promote its medicinal value.
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Affiliation(s)
- Xiaohu Wang
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, No. 2, Zheshan West Road, Jinghu District, Wuhu, 241000, China
- Wannan Medical College, No.22, Wenchang West Road, Yijiang District, Wuhu, 241000, China
| | - Xingwen Wang
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, No. 2, Zheshan West Road, Jinghu District, Wuhu, 241000, China
| | - Hui Yao
- Wannan Medical College, No.22, Wenchang West Road, Yijiang District, Wuhu, 241000, China
| | - Chaozhuang Shen
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, No. 2, Zheshan West Road, Jinghu District, Wuhu, 241000, China
| | - Kuo Geng
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, No. 2, Zheshan West Road, Jinghu District, Wuhu, 241000, China
| | - Haitang Xie
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, No. 2, Zheshan West Road, Jinghu District, Wuhu, 241000, China.
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Shao W, Shen C, Wang W, Sun H, Wang X, Geng K, Wang X, Xie H. Development and Validation of Physiologically Based Pharmacokinetic Model of Levetiracetam to Predict Exposure and Dose Optimization in Pediatrics. J Pharm Sci 2023; 112:2667-2675. [PMID: 37023853 DOI: 10.1016/j.xphs.2023.03.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 03/29/2023] [Accepted: 03/29/2023] [Indexed: 04/08/2023]
Abstract
Levetiracetam (Lev) is an antiepileptic drug that has been increasingly used in the epilepsy pediatric population in recent years, but its pharmacokinetic behavior in pediatric population needs to be characterized clearly. Clinical trials for the pediatric drug remain difficult to conduct due to ethical and practical factors. The purpose of this study was to use the physiologically based pharmacokinetic (PBPK) model to predict changes in plasma exposure of Lev in pediatric patients and to provide recommendations for dose adjustment. A PBPK model of Lev in adults was developed using PK-Sim® software and extrapolated to the entire age range of the pediatric population. The model was evaluated using clinical pharmacokinetic data. The results showed the good fit between predictions and observations of the adult and pediatric models. The recommended doses for neonates, infants and children are 0.78, 1.67 and 1.22 times that of adults, respectively. Moreover, at the same dose, plasma exposure in adolescents was similar to that of adults. The PBPK models of Lev for adults and pediatrics were successfully developed and validated to provide a reference for the rational administration of drugs in the pediatric population.
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Affiliation(s)
- Wenxin Shao
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu 241001, Anhui, China
| | - Chaozhuang Shen
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu 241001, Anhui, China
| | - Wenhui Wang
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu 241001, Anhui, China
| | - Hua Sun
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu 241001, Anhui, China
| | - Xiaohu Wang
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu 241001, Anhui, China
| | - Kuo Geng
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu 241001, Anhui, China
| | - Xingwen Wang
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu 241001, Anhui, China
| | - Haitang Xie
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu 241001, Anhui, China.
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Wang X, Shen C, Wang X, Tang J, Wu Z, Huang Y, Shao W, Geng K, Xie H, Pu Z. Schisandrin protects against ulcerative colitis by inhibiting the SGK1/NLRP3 signaling pathway and reshaping gut microbiota in mice. Chin Med 2023; 18:112. [PMID: 37674245 PMCID: PMC10481484 DOI: 10.1186/s13020-023-00815-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 08/08/2023] [Indexed: 09/08/2023] Open
Abstract
BACKGROUND According to the Chinese Pharmacopoeia, the fruit of Schisandra chinensis (Turcz.) Baill. (SC) is an important traditional Chinese medicine that can be used to treat diarrhea. Despite the increasing research on the anti-inflammatory and anti-oxidant aspects of SC, the studies on the anti-ulcerative colitis of Schisandrin (SCH), the main constituent of SC, are relatively few. METHODS The mice used in the study were randomly distributed into 6 groups: control, model, 5-ASA, and SCH (20, 40, 80 mg/kg/d). The mice in the model group were administered 3% (w/v) dextran sulfate sodium (DSS) through drinking water for 7 days, and the various parameters of disease activity index (DAI) such as body weight loss, stool consistency, and gross blood were measured. ELISA was used to detect inflammatory factors, and bioinformatics combined with transcriptome analysis was done to screen and verify relevant targets. 16S rDNA high-throughput sequencing was used to analyze the composition of the gut microbiota(GM), while mass spectrometry was done to analyze the changes in the content of bile acids (BAs) in the intestine. RESULTS Mice treated with SCH experienced significant weight gain, effectively alleviating the severity of colitis, and decreasing the levels of inflammatory factors such as TNF-α, IL-1β, IL-18, IL-6, and other related proteins (NLRP3, Caspase-1, SGK1) in UC mice. Furthermore, the analysis of GM and BAs in mice revealed that SCH increased the relative abundance of Lactobacilli spp, reduced the relative abundance of Bacteroides, and promoted the conversion of primary BAs to secondary BAs. These effects contributed to a significant improvement in the DSS-induced GM imbalance and the maintenance of intestinal homeostasis. CONCLUSION It seems that there is a close relationship between the SCH mechanism and the regulation of SGK1/NLRP3 pathway and the restoration of GM balance. Therefore, it can be concluded that SCH could be a potential drug for the treatment of UC.
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Affiliation(s)
- Xiaohu Wang
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, No. 2, Zheshan West Road, Jinghu District, Wuhu, 241000, China
- Graduate School of Wannan Medical College, No.22, Wenchang West Road, Yijiang District, Wuhu, 241000, China
| | - Chaozhuang Shen
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, No. 2, Zheshan West Road, Jinghu District, Wuhu, 241000, China
| | - Xingwen Wang
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, No. 2, Zheshan West Road, Jinghu District, Wuhu, 241000, China
| | - Jin Tang
- Graduate School of Wannan Medical College, No.22, Wenchang West Road, Yijiang District, Wuhu, 241000, China
| | - Zijing Wu
- Department of Pharmacy, Bengbu First People's Hospital, Bengbu, 233000, China
| | - Yunzhe Huang
- Graduate School of Wannan Medical College, No.22, Wenchang West Road, Yijiang District, Wuhu, 241000, China
| | - Wenxin Shao
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, No. 2, Zheshan West Road, Jinghu District, Wuhu, 241000, China
| | - Kuo Geng
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, No. 2, Zheshan West Road, Jinghu District, Wuhu, 241000, China
| | - Haitang Xie
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, No. 2, Zheshan West Road, Jinghu District, Wuhu, 241000, China.
| | - Zhichen Pu
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, No. 2, Zheshan West Road, Jinghu District, Wuhu, 241000, China.
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Shen C, Shao W, Wang W, Sun H, Wang X, Geng K, Wang X, Xie H. Physiologically Based Pharmacokinetic Modeling of Levetiracetam to Predict the Exposure in Hepatic and Renal Impairment and Elderly Populations. CPT Pharmacometrics Syst Pharmacol 2023. [PMID: 37170680 DOI: 10.1002/psp4.12971] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 04/06/2023] [Accepted: 04/10/2023] [Indexed: 05/13/2023] Open
Abstract
Levetiracetam (LEV) is an anti-epileptic drug (AED) approved for use in various populations. The Pharmacokinetic (PK) behavior of LEV may be altered in the elderly and patients with renal and hepatic impairment. Thus, dosage adjustment is required. This study was conducted to investigate how the physiologically based pharmacokinetic (PBPK) model describes the pharmacokinetics of LEV in adult and elderly populations, as well as to predict the pharmacokinetics of LEV in patients with renal and hepatic impairment in both populations. The whole-body PBPK models were developed using the reported physicochemical properties of LEV and clinical data. The models were validated using data from clinical studies with different dose ranges and different routes and intervals of administration. The fit performance of the models was assessed by comparing predicted and observed blood concentration data and PK parameters. It is recommended that the doses be reduced to approximately 70%, 60% and 45% of the adult dose for the mild, moderate and severe renal impairment populations and approximately 95%, 80% and 57% of the adult dose for the Child Pugh-A (CP-A), Child Pugh-B (CP-B), and Child Pugh-C (CP-C) hepatic impairment populations, respectively. No dose adjustment is required for the healthy elderly population, but dose reduction is required for the elderly with organ dysfunction accordingly, on a scale similar to that of adults. A PBPK model of LEV was successfully developed to optimize dosing regimens for special populations.
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Affiliation(s)
- Chaozhuang Shen
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu, Anhui, China
| | - Wenxin Shao
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu, Anhui, China
| | - Wenhui Wang
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu, Anhui, China
| | - Hua Sun
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu, Anhui, China
| | - Xiaohu Wang
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu, Anhui, China
| | - Kuo Geng
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu, Anhui, China
| | - Xingwen Wang
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu, Anhui, China
| | - Haitang Xie
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu, Anhui, China
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Shen C, Shen P, Wang X, Wang X, Shao W, Geng K, Xie H. Integrating Bioinformatics and Network Pharmacology to Explore the Therapeu-tic Target and Molecular Mechanisms of Schisandrin on Hypertrophic Cardio-myopathy. Curr Comput Aided Drug Des 2022; 19:192-201. [PMID: 36424782 DOI: 10.2174/1573409919666221124144713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 10/01/2022] [Accepted: 10/21/2022] [Indexed: 11/27/2022]
Abstract
Background:
Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease and is currently the leading cause of sudden death in adolescent athletes. Schisandrin is a quality marker of the traditional Chinese medicine Schisandra chinen-sis, which has an excellent therapeutic effect on HCM, but its pharmacological mecha-nism remains unclear.
Objective:
This study aimed to explore the potential and provide scientific evidence for schisandrin as a lead compound against hypertrophic cardiomyopathy.
Methods:
The drug-like properties of schisandrin were predicted using the Swis-sADME website. Then, the PharmMapper database was used to predict potential drug targets and match gene names in the Uniprot database. HCM targets were collected from NCBI, OMIM, and Genecards databases and intersected with drug targets. The intersection targets were imported into the STRING database for PPI analysis, and core targets were identified. KEGG and GO enrichment analysis was performed on the core targets through the DAVID database, and all network maps were imported into Cyto-scape software for visualization optimization. HCM-related datasets were downloaded from the GEO database to analyze core targets and screen differentially expressed target genes for molecular docking.
Results:
After the PPI network analysis of the intersection targets of drugs and diseases, 12 core targets were screened out. The KEGG analysis results showed that they were mainly involved in Rap1, TNF, FoxO, PI3K-Akt, and other signaling pathways. After differential analysis, PPARG, EGFR, and MMP3 targets were also screened. The mo-lecular docking results showed that schisandrin was well bound to the protein backbone of each target.
Conclusion:
This study used network pharmacology combined with differential expres-sion and molecular docking to predict that schisandrin may treat HCM by acting on PPARG, EGFR, and MMP3 targets, and the regulatory process may involve signaling pathways, such as Rap1, TNF, FoxO, and PI3K-Akt, which may provide a valuable reference for subsequent studies.
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Affiliation(s)
- Chaozhuang Shen
- Graduate School, Wannan Medical College, Wuhu 241002, Anhui Province, China
| | - Pingping Shen
- School of Medical Information, Wannan Medical College, Wuhu, Anhui Province 241002, China
| | - Xiaohu Wang
- Graduate School, Wannan Medical College, Wuhu 241002, Anhui Province, China
| | - Xingwen Wang
- Graduate School, Wannan Medical College, Wuhu 241002, Anhui Province, China
| | - Wenxin Shao
- Graduate School, Wannan Medical College, Wuhu 241002, Anhui Province, China
| | - Kuo Geng
- Graduate School, Wannan Medical College, Wuhu 241002, Anhui Province, China
| | - Haitang Xie
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu 241001, Anhui Province, China
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Shen C, Liang D, Wang X, Shao W, Geng K, Wang X, Sun H, Xie H. Predictive performance and verification of physiologically based pharmacokinetic model of propylthiouracil. Front Pharmacol 2022; 13:1013432. [PMID: 36278167 PMCID: PMC9579312 DOI: 10.3389/fphar.2022.1013432] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
Background: Propylthiouracil (PTU) treats hyperthyroidism and thyroid crisis in all age groups. A variety of serious adverse effects can occur during clinical use and require attention to its pharmacokinetic and pharmacodynamic characteristics in various populations.Objective: To provide information for individualized dosing and clinical evaluation of PTU in the clinical setting by developing a physiologically based pharmacokinetic (PBPK) model, predicting ADME characteristics, and extrapolating to elderly and pediatric populations.Methods: Relevant databases and literature were retrieved to collect PTU’s pharmacochemical properties and ADME parameters, etc. A PBPK model for adults was developed using PK-Sim® software to predict tissue distribution and extrapolated to elderly and pediatric populations. The mean fold error (MFE) method was used to compare the differences between predicted and observed values to assess the accuracy of the PBPK model. The model was validated using PTU pharmacokinetic data in healthy adult populations.Result: The MFE ratios of predicted to observed values of AUC0-t, Cmax, and Tmax were mainly within 0.5 and 2. PTU concentrations in various tissues are lower than venous plasma concentrations. Compared to healthy adults, the pediatric population requires quantitative adjustment to the appropriate dose to achieve the same plasma exposure levels, while the elderly do not require dose adjustments.Conclusion: The PBPK model of PTU was successfully developed, externally validated, and applied to tissue distribution prediction and special population extrapolation, which provides a reference for clinical individualized drug administration and evaluation.
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Affiliation(s)
- Chaozhuang Shen
- Graduate School, Wannan Medical College, Wuhu, Anhui, China
- *Correspondence: Chaozhuang Shen, ; Hua Sun, ; Haitang Xie,
| | - Dahu Liang
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu, Anhui, China
| | - Xiaohu Wang
- Graduate School, Wannan Medical College, Wuhu, Anhui, China
| | - Wenxin Shao
- Graduate School, Wannan Medical College, Wuhu, Anhui, China
| | - Kuo Geng
- Graduate School, Wannan Medical College, Wuhu, Anhui, China
| | - Xingwen Wang
- Graduate School, Wannan Medical College, Wuhu, Anhui, China
| | - Hua Sun
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu, Anhui, China
- *Correspondence: Chaozhuang Shen, ; Hua Sun, ; Haitang Xie,
| | - Haitang Xie
- Anhui Provincial Center for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu, Anhui, China
- *Correspondence: Chaozhuang Shen, ; Hua Sun, ; Haitang Xie,
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Abreu E, Meyers D, Thorsmølle VK, Zhang J, Liu X, Geng K, Chakhalian J, Averitt RD. Nucleation and Growth Bottleneck in the Conductivity Recovery Dynamics of Nickelate Ultrathin Films. Nano Lett 2020; 20:7422-7428. [PMID: 32902285 DOI: 10.1021/acs.nanolett.0c02828] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We investigate THz conductivity dynamics in NdNiO3 and EuNiO3 ultrathin films (15 unit cells, u.c., ∼5.7 nm thick) following a photoinduced thermal quench into the metallic state and reveal a clear contrast between first- and second-order dynamics. While in EuNiO3 the conductivity recovers exponentially, in NdNiO3 the recovery is nonexponential and slower than a simple thermal model. Crucially, it is consistent with first-order dynamics and well-described by a 2d Avrami model, with supercooling leading to metastable phase coexistence on the nano- to mesoscopic scale. This novel observation is a fundamentally dynamic manifestation of the first-order character of the insulator-to-metal transition, which the nanoscale thickness of our films and their fast cooling rate enable us to detect. The large transients seen in our films are promising for fast electronic (and magnetic) switching applications.
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Affiliation(s)
- E Abreu
- Institute for Quantum Electronics, Department of Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - D Meyers
- Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078, United States
| | - V K Thorsmølle
- Department of Physics, Boston University, Boston, Massachusetts 02215, United States
- Department of Physics, UC San Diego, La Jolla, California 92093, United States
| | - J Zhang
- Department of Physics, UC San Diego, La Jolla, California 92093, United States
- Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - X Liu
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, United States
| | - K Geng
- Department of Physics, Boston University, Boston, Massachusetts 02215, United States
| | - J Chakhalian
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, United States
| | - R D Averitt
- Department of Physics, UC San Diego, La Jolla, California 92093, United States
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Geng K, Wu L, Gao Q. Re: "Comparison between flapless and open-flap implant placement: a systematic review and meta-analysis". Int J Oral Maxillofac Surg 2018; 48:416. [PMID: 30126767 DOI: 10.1016/j.ijom.2018.07.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Accepted: 07/27/2018] [Indexed: 11/30/2022]
Affiliation(s)
- K Geng
- Department of Prosthodontics, Xiangya Hospital, Central South University, Changsha, China
| | - L Wu
- Department of Prosthodontics, Xiangya Hospital, Central South University, Changsha, China
| | - Q Gao
- Department of Prosthodontics, Xiangya Hospital, Central South University, Changsha, China.
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Geng K, Huang D, Wu R. Tracking of mesenchymal stem cells labeled with Gd-Dtpa by Mr imaging in cerebral ischemia model. J Neurol Sci 2013. [DOI: 10.1016/j.jns.2013.07.702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Abstract
Lactoferrin is an iron-binding glycoprotein present in high concentrations in milk and exocrine fluids such as bile and tears. Many functions have been attributed to lactoferrin, including antimicrobial and antiviral activities, immunomodulation, and cell growth regulation. Lactoferrin expression is controlled by different regulators, including retinoic acid and estrogen. However, the expression pattern of lactoferrin in mammalian early development has not yet been reported. Murine embryonic stem cells are pluripotent cells that can contribute to all tissues and were used for this study. We show here that while no lactoferrin protein or mRNA was detected in untreated murine embryonic stem cells, retinoic acid and estrogen can induce high levels lactoferrin expression in these cells. Expression, demonstrated by reverse transcription-polymerase chain reaction, Western blot, immunofluorescence, and ELISA assay, was dose and time dependent. Our study provides an in vitro model for examining lactoferrin expression in early development and differentiation.
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Affiliation(s)
- K Geng
- Department of Biology, New York University, New York, New York, 10003, USA
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