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Guo L, Wong PL, Guo F, Liu HC. Determination of thin hydrodynamic lubricating film thickness using dichromatic interferometry. APPLIED OPTICS 2014; 53:6066-6072. [PMID: 25321689 DOI: 10.1364/ao.53.006066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Accepted: 08/07/2014] [Indexed: 06/04/2023]
Abstract
This paper introduces the application of dichromatic interferometry for the study of hydrodynamic lubrication. In conventional methods, two beams with different colors are projected consecutively on a static object. By contrast, the current method deals with hydrodynamic lubricated contacts under running conditions and two lasers with different colors are projected simultaneously to form interference images. Dichromatic interferometry incorporates the advantages of monochromatic and chromatic interferometry, which are widely used in lubrication research. This new approach was evaluated statically and dynamically by measuring the inclination of static wedge films and the thickness of the hydrodynamic lubricating film under running conditions, respectively. Results show that dichromatic interferometry can facilitate real-time determination of lubricating film thickness and is well suited for the study of transient or dynamic lubricating problems.
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Liu HC, Shen MC, Eng HL, Wang CH, Lin TM. Asp68His mutation in the A1 domain of human factor V causes impaired secretion and ineffective translocation. Haemophilia 2014; 20:e318-26. [PMID: 24893683 DOI: 10.1111/hae.12476] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/28/2014] [Indexed: 11/30/2022]
Abstract
Congenital factor V (FV) deficiency is a rare inherited disorder. We determined the mechanism of a missense mutation, Asp68His, in the A1 domain of the FV protein, is associated with severe FV deficiency. We characterized the mutant FV-Asp68His protein using in vitro expression studies by using specific secretion and degradation pathway inhibitors and analysed the intracellular translocation of the mutant protein by immunofluorescence staining. The Asp68His mutation caused very low levels of FV protein in the conditioned media, with normal specific FV activity. Similar mRNA degradation rates between FV-wild-type (wt) and FV-Asp68His mRNA showed that the Asp68His mutation does not affect FV expression at the transcriptional level. A specific secretion pathway inhibitor, brefeldin A, was used to demonstrate that the lower efficiency of transport to the outside of the cell for FV-Asp68His mutant protein compared with that of the FV-wt protein. Furthermore, we showed that the Asp68His mutation resulted in increased intracellular degradation through a MG132-mediated proteasomal degradation pathway. In the transfected cell lysates, FV-wt protein had multiple posttranslational modified forms, but the FV-Asp68His protein was not completely glycosylated. We further observed that the FV-Asp68His protein was retrieved in the endoplasmic reticulum only and did not undergo transport to the Golgi apparatus, leading to impaired secretion. These results strongly suggest that the Asp68His mutation may result in intracellular defective trafficking and enhanced degradation, and impaired secretion of FV protein.
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Bing L, Wu XP, Feng Y, Wang YJ, Liu HC. Palatal Rugae for the Construction of Forensic Identification. INT J MORPHOL 2014. [DOI: 10.4067/s0717-95022014000200028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Liu HC, Zhang J, Wong S, Han D, Zhao HS, Feng HL. Association between rs11001553 of DKK1 and non-syndromic tooth agenesis in the Chinese Han population. GENETICS AND MOLECULAR RESEARCH 2014; 13:7133-9. [PMID: 24737523 DOI: 10.4238/2014.april.3.4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Tooth agenesis is one of the most common anomalies of human dentition. Recent genetic studies have provided information regarding a number of genes related to both syndromic and non-syndromic forms of hypodontia. In a previous study, we found that polymorphism in rs11001553 of DKK1 was associated with hypodontia in the Chinese Han population. In this study, we extended this investigation to 89 individuals diagnosed with sporadic non-syndromic oligodontia (40 males and 49 females). These individuals were analyzed with 268 subjects (123 males and 145 females) diagnosed with non-syndromic hypodontia and 190 healthy control subjects (99 males and 91 females). DNA was obtained from whole blood or saliva samples and genotyping was performed by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Significant differences were observed in the allele and genotype frequencies of rs11001553 of DKK1. These data demonstrated an association between rs11001553 of DKK1, a tooth development-associated gene, and non-syndromic tooth agenesis in Chinese Han individuals. This information may provide further understanding of the molecular mechanisms of tooth agenesis. Furthermore, DKK1 can be regarded as a marker gene for the risk of tooth agenesis.
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Wu H, Liu HC, E L, Liu N, Zhang B, Gao Y, Feng L. [Effect of the peri-implantitis on the biological function of osteoblasts obtained from the mandibles]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2014; 32:130-133. [PMID: 24881205 PMCID: PMC7030812 DOI: 10.7518/hxkq.2014.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 12/08/2013] [Indexed: 06/03/2023]
Abstract
OBJECTIVE To study the effect of peri-implantitis inflammatory microenvironment on the biological function of jaw bone osteoblasts. METHODS Primary mandible osteoblasts from peri-implantitis and normal tissue were isolated and cultured. Third-generation purified osteoblasts were identified and detected. The proliferative activity of osteoblasts was evaluated through MTT assay. Osteocalcin (OCN), Runx2, and collagen I (Col I) mRNA levels were examined by real-time quantitative polymerase chain reaction. OCN protein levels were determined by Western blot. RESULTS : After 4 d of culture, the proliferative activity of osteoblasts from peri-implantitis became lower than that of normal tissue ( P <0.05). After 7 d of culture, OCN, Runx2, and Col I mRNA expression decreased ( P <0.05). The OCN protein levels also decreased ( P <0.05). CONCLUSION Peri-implantitis inflammatory microenvironment can decrease the proliferation and differentiation activity of mandible osteoblasts.
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Liu M, Wang XL, Zhang D, Yang M, Han J, Zhang YN, Wang ZL, Liu HC. Pharmacokinetics of niacin, simvastatin and their metabolites in healthy Chinese subjects after single and multiple doses of a fixed dose combination tablet of niacin extended release/simvastatin. Drug Res (Stuttg) 2013; 64:296-300. [PMID: 24154936 DOI: 10.1055/s-0033-1357190] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE A fixed dose combination tablet of niacin extended release (ER)/simvastatin was recently developed in China. This study was designed to assess and compare the pharmacokinetics of niacin, simvastatin and their metabolites in healthy Chinese subjects after single and multiple doses administration. METHODS From day 1 to day 7, 12 Chinese subjects were given a tablet every day at approximately 10 p.m. Serial blood samples were collected. Niacin and nicotinuric acid (NUA) in plasma, niacin, NUA, N-methylnicotinamide (MNA) and N-methyl-2-pyridone-5-carboxamide (2PY) in urine, simvastatin and simvastatin acid in plasma were determined by LC/MS/MS methods. Pharmacokinetic parameters on days 1 and 7 were compared. RESULTS The main pharmacokinetic parameters for the single and multiple doses were as -follows: Niacin: Tmax were 3.8±1.5 h and 3.9±2.0 h; Cmax were 2 091±1 315 ng/ml and 2 323±1 542 ng/ml; AUC0-t were 4 123.88±3 138.48 ng ∙ h/ml and 4 385.98±3 127.05 ng ∙ h/ml. NUA: Tmax were 4.7±1.7 h and 3.8±1.5 h; Cmax were 1 057±549 ng/ml and 1 087±470 ng/ml; AUC0-t were 4 012.49±2 168.68 ng ∙ h/ml and 4 040.45±1 886.57 ng ∙ h/ml. Simvastatin: Tmax were 1.8±1.0 h and 2.5±2.5 h; Cmax were 3.15±1.67 ng/ml and 4.87±4.11 ng/ml; AUC0-t were 9.03±5.10 ng ∙ h/ml and 17.63±13.93 ng ∙ h/ml. Simvastatin acid: Tmax were 5.8±1.7 h and 6.5±1.4 h; Cmax were 4.22±2.10 ng/ml and 9.30±8.09 ng/ml; AUC0-t were 34.65±16.89 ng ∙ h/ml and 61.62±46.41 ng ∙ h/ml. Urine Recovery rate of total niacin: (40.55±7.38)% and (62.87±12.04)%. CONCLUSION Compared with those after a single dose, pharmacokinetics of niacin and NUA was similar; total urine recovery of niacin was higher; exposure to simvastatin and simvastatin acid were higher following multiple doses.
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Leng Y, Lu T, Yuan HL, Liu HC, Lu S, Zhang WW, Jiang YL, Chen YD. QSAR studies on imidazopyrazine derivatives as Aurora A kinase inhibitors. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2012; 23:705-730. [PMID: 22971111 DOI: 10.1080/1062936x.2012.719541] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Aurora kinases have emerged as attractive targets for the development of novel anti-cancer agents. A combined study of molecular docking, pharmacophore modelling and 3D-QSAR was performed on a series of imidazo [1, 2-a] pyrazines as novel Aurora kinase inhibitors to gain insights into the structural determinants and their structure-activity relationship. An ensemble of conformations based on molecular docking was used for PHASE pharmacophore studies. The developed best-fitted pharmacophore model was validated by diverse chemotypes of Aurora A kinase inhibitors and was consistent with the structural requirements for the docked binding mechanism. Subsequently, the pharmacophore-based alignment was used to develop PHASE and comparative molecular similarity indices analysis (CoMSIA) 3D-QSAR models. The best CoMSIA model showed good statistics (q (2 )= 0.567, r (2 )= 0.992), and the predictive ability of the model was validated using an external test set of 13 compounds giving a satisfactory prediction ([Formula: see text]). The 3D contour maps provided insight into the binding mechanism and highlighted key structural features that are essential to the inhibitory activity. Based on the PHASE and CoMSIA 3D-QSAR results, a set of novel Aurora A inhibitors were designed that showed excellent potencies.
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Yu SJ, Liu HC, Ling-Ling E, Wang DS, Zhu GX. Proliferation and differentiation of osteoblasts from the mandible of osteoporotic rats. Exp Biol Med (Maywood) 2012; 237:395-406. [PMID: 22550338 DOI: 10.1258/ebm.2011.011217] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The objective of this study was to identify the differences between osteoblasts derived from normal adult rat mandibles and osteoporotic adult rats. An osteoporotic animal model was established by performing a bilateral ovariectomy (ovx group). The proliferation and differentiation abilities of osteoblasts were determined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-2H-tetrazolium bromide), alkaline phosphatase (ALP) and osteocalcin release (OC) assays. Transmission electron microscopy (TEM) was performed to assess differences in the ultrastructure. Proliferating cell nuclear antigen (PCNA) and uncoupling protein 2 (UCP2) protein concentrations were analyzed by Western blot. In addition, UCP2 protein in osteoblasts was assessed by immunohistochemistry staining. ATP and reactive oxygen species (ROS) concentrations were analyzed separately with ATP and ROS quantification kits. At four and 12 weeks after the operation, osteoblasts of the ovx group showed earlier attachment, fewer dead cells and faster growth compared with cells in the sham group. TEM showed that osteoblasts of the ovx group had fewer folds, lysosomes, peroxisomes and less rough endoplasmic reticulum. The results of the MTT, ALP activity and OC assays were all higher in osteoblasts from the ovx group at four or 12 weeks postsurgery than osteoblasts from the sham group. PCNA protein concentrations in the ovx group increased significantly compared with those of the sham group at four or 12 weeks after the operation, but UCP2 concentrations decreased over the same time period. UCP2 immunohistochemical staining of osteoblasts showed that the protein was concentrated in the cytoplasm and that the osteoblasts from the sham group had higher expression than those from the ovx group. The ATP and ROS concentrations of the ovx groups were significantly higher than the sham groups at four or 12 weeks postsurgery. Therefore, we concluded that there are differences in cell ultrastructure, proliferation, differentiation, ATP and ROS concentrations, and PCNA and UCP2 protein expression levels in osteoblasts from the mandibles of rats of the ovx group compared with those from the sham group.
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Fathololoumi S, Dupont E, Chan CWI, Wasilewski ZR, Laframboise SR, Ban D, Mátyás A, Jirauschek C, Hu Q, Liu HC. Terahertz quantum cascade lasers operating up to ∼ 200 K with optimized oscillator strength and improved injection tunneling. OPTICS EXPRESS 2012; 20:3866-3876. [PMID: 22418143 DOI: 10.1364/oe.20.003866] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A new temperature performance record of 199.5 K for terahertz quantum cascade lasers is achieved by optimizing the lasing transition oscillator strength of the resonant phonon based three-well design. The optimum oscillator strength of 0.58 was found to be larger than that of the previous record (0.41) by Kumar et al. [Appl. Phys. Lett. 94, 131105 (2009)]. The choice of tunneling barrier thicknesses was determined with a simplified density matrix model, which converged towards higher tunneling coupling strengths than previously explored and nearly perfect alignment of the states across the injection and extraction barriers at the design electric field. At 8 K, the device showed a threshold current density of 1 kA/cm2, with a peak output power of ∼ 38 mW, and lasing frequency blue-shifting from 2.6 THz to 2.85 THz with increasing bias. The wavelength blue-shifted to 3.22 THz closer to the maximum operating temperature of 199.5 K, which corresponds to ∼ 1.28ħω/κB. The voltage dependence of laser frequency is related to the Stark effect of two intersubband transitions and is compared with the simulated gain spectra obtained by a Monte Carlo approach.
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Hinds S, Buchanan M, Dudek R, Haffouz S, Laframboise S, Wasilewski Z, Liu HC. Near-room-temperature mid-infrared quantum well photodetector. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2011; 23:5536-5539. [PMID: 22052780 DOI: 10.1002/adma.201103372] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Indexed: 05/31/2023]
Abstract
We demonstrate InGaAs mid-infrared quantum well infrared photodetectors (MIR PV-QWIPs) that enable cost-effective mature GaAs-based detection and imaging technologies, with exceptional material uniformity, reproducibility, and yield, over a large area, with high spectral selectivity, innate polarization sensitivity, radiation hardness, high detectivity, and high speed operation at TEC temperatures without bias.
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Liu HC, E LL, Wang DS, Su F, Wu X, Shi ZP, Lv Y, Wang JZ. Reconstruction of alveolar bone defects using bone morphogenetic protein 2 mediated rabbit dental pulp stem cells seeded on nano-hydroxyapatite/collagen/poly(L-lactide). Tissue Eng Part A 2011; 17:2417-33. [PMID: 21563858 DOI: 10.1089/ten.tea.2010.0620] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The objective of the present study was to evaluate the capacity of a tissue-engineered bone complex of recombinant human bone morphogenetic protein 2 (rhBMP-2)-mediated dental pulp stem cells (DPSCs) and nano-hydroxyapatite/collagen/poly(L-lactide) (nHAC/PLA) to reconstruct critical-size alveolar bone defects in New Zealand rabbit. Autologous DPSCs were isolated from rabbit dental pulp tissue and expanded ex vivo to enrich DPSCs numbers, and then their attachment and differentiation capability were evaluated when cultured on the culture plate or nHAC/PLA. The alveolar bone defects were treated with nHAC/PLA, nHAC/PLA+rhBMP-2, nHAC/PLA+DPSCs, nHAC/PLA+DPSCs+rhBMP-2, and autogenous bone (AB) obtained from iliac bone or were left untreated as a control. X-ray and a polychrome sequential fluorescent labeling were performed postoperatively and the animals were sacrificed 12 weeks after operation for histological observation and histomorphometric analysis. Our results showed that DPSCs expressed STRO-1 and vementin, and favored osteogenesis and adipogenesis in conditioned media. DPSCs attached and spread well, and retained their osteogenic phenotypes on nHAC/PLA. The rhBMP-2 could significantly increase protein content, alkaline phosphatase activity/protein, osteocalcin content, and mineral formation of DPSCs cultured on nHAC/PLA. The X-ray graph, the fluorescent, histological observation, and histomorphometric analysis showed that the nHAC/PLA+DPSCs+rhBMP-2 tissue-engineered bone complex had an earlier mineralization and more bone formation inside the scaffold than nHAC/PLA, nHAC/PLA+rhBMP-2, and nHAC/PLA+DPSCs, or even autologous bone. Implanted DPSCs' contribution to new bone was detected through transfected eGFP genes. Our findings indicated that stem cells existed in adult rabbit dental pulp tissue. The rhBMP-2 promoted osteogenic capability of DPSCs as a potential cell source for periodontal bone regeneration. The nHAC/PLA could serve as a good scaffold for autologous DPSC seeding, proliferation, and differentiation. The tissue-engineered bone complex with nHAC/PLA, rhBMP-2, and autologous DPSCs might be a better alternative to autologous bone for the clinical reconstruction of periodontal bone defects.
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Han X, Liu HC, Wang DS, Li SJ, Yang R. [Scanning electron microscopy observation of the growth of osteoblasts on Ti-24Nb-4Zr-8Sn modified by micro-arc oxidation and alkali-heat treatment and implant-bone interface]. ZHONGHUA KOU QIANG YI XUE ZA ZHI = ZHONGHUA KOUQIANG YIXUE ZAZHI = CHINESE JOURNAL OF STOMATOLOGY 2011; 46:50-53. [PMID: 21418948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
OBJECTIVE To observe the efficacy of micro-arc oxidation and alkali-heat treatment (MAH) on Ti-24Nb-4Zr-8Sn (Ti2448). METHODS Disks (diameter of 14.5 mm, thickness of 1 mm) and cylinders (diameter of 3 mm, height of 10 mm) were fabricated from Ti2448 alloy. Samples were divided into three groups: polished (Ti2448), micro-arc oxidation(MAO-Ti2448), micro-arc oxidation and alkali-heat treatment (MAH-Ti2448). MC3T3-E1 osteoblastic cells were cultured on the disks and cell morphology was observed with scanning electron microscopy (SEM) aftre 3 days. The cylinder samples were implanted in the tibia of dogs and implant-bone interface was observed with SEM after 3 months. RESULTS A rough and porous structure was shown in both MAO and MAH group. The MC3T3-E1 cells on the MAH-Ti2448 discs spread fully in intimate contact with the underlying coarse surface through active cytoskeletal extentions. Osseointegration was formed in the implant-bone interface in MAH samples. CONCLUSIONS MAH treatment can provide a more advantageous Ti2448 surface to osteoblastic cells than MAO treatment does, and the former can improve the implant-bone integration.
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Jiang H, Wang ZW, Liu HC, Hu M, Cao JK, Shi XW. [Effect of right chewing-side preference on morphological temporomandibular joint changes]. SHANGHAI KOU QIANG YI XUE = SHANGHAI JOURNAL OF STOMATOLOGY 2010; 19:607-610. [PMID: 21431260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
PURPOSE To explore the effect of right chewing-side preference on temporomandibular joint with cone-beam computed tomography (CBCT). METHODS Fifty-two patients who were diagnosed as right chewing-side preference were selected and scanned by CBCT in the intercuspal position. The interested region was chosen to reconstruct and the images of bony structure of TMJ at axial view, coronal position, sagittal position, oblique position parallelled to the long axis of condyle and oblique position vertical to the long axis of condyle were evaluated. The data was analyzed with SPSS12.0 software package for paired t test. RESULTS There was significant difference between the habitual and unhabitual sides of the joint space of 60° and 90° at oblique position parallelled to the long axis of condyle (P<l0.05), as well as the joint space of 120° and 150° or the thickness of neck of condyle at sagittal position and the oblique position vertical to the long axis of condyle (P<0.01). No significant difference was found in the rest measuring values. CONCLUSION The results indicate that right chewing-side preference affects the morphology of temporomandibular joint. Supported by National Natural Science Foundation of China (Grant No.30772450) and the Nursery Fund of General Hospital of Chinese PLA (Grant No.09KMM11).
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E LL, Xu LL, Wu X, Wang DS, Lv Y, Wang JZ, Liu HC. The Interactions Between Rat-Adipose-Derived Stromal Cells, Recombinant Human Bone Morphogenetic Protein-2, and Beta-Tricalcium Phosphate Play an Important Role in Bone Tissue Engineering. Tissue Eng Part A 2010; 16:2927-40. [PMID: 20486786 DOI: 10.1089/ten.tea.2010.0018] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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Fuh JL, Liu HC, Wang SJ, Lo YK, Lee LS. Nontraumatic hemorrhagic stroke in young adults in taiwan. J Stroke Cerebrovasc Dis 2010; 4:101-5. [PMID: 26487610 DOI: 10.1016/s1052-3057(10)80117-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We reviewed the medical records and imaging studies on the in-hospital patients to investigate the clinical and etiological patterns in hemorrhagic stroke in young patients. We evaluated 210 patients (131 males and 79 females) aged 15-45 years who had traumatic hemorrhagic stroke between April 1, 1986, and November 30, 1992. Nontraumatic intracerebral hemorrhage was diagnosed in 170 patients (80.9%). The main causes of nontraumatic intracerebral hemorrhage were hypertension, ruptured arteriovenous malformation, and blood dyscrasia. A cause was not found in 42 patients (24.7%). Subarachnoid hemorrhage was found in 40 patients (19.1%). The main causes were ruptured aneurysms and arteriovenous malformations. The overall in-hospital survival of young patients with hemorrhagic stroke was 64.7%. Young adults with nontraumatic intracerebral and subarachnoid hemorrhage are a heterogeneous group. Hypertension accounts for about one-third of intracerebral hemorrhage and is an important preventable cause of hemorrhagic stroke in young adults in Taiwan.
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Fathololoumi S, Dupont E, Razavipour SG, Laframboise SR, Delage A, Wasilewski ZR, Bezinger A, Rafi GZ, Safavi-Naeini S, Ban D, Liu HC. Electrically switching transverse modes in high power THz quantum cascade lasers. OPTICS EXPRESS 2010; 18:10036-10048. [PMID: 20588857 DOI: 10.1364/oe.18.010036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The design and fabrication of a high power THz quantum cascade laser (QCL), with electrically controllable transverse mode is presented. The switching of the beam pattern results in dynamic beam switching using a symmetric side current injection scheme. The angular-resolved L-I curves measurements, near-field and far-field patterns and angular-resolved lasing spectra are presented. The measurement results confirm that the quasi-TM(01) transverse mode lases first and dominates the lasing operation at lower current injection, while the quasi-TM(00) mode lases at a higher threshold current density and becomes dominant at high current injection. The near-field and far-field measurements confirm that the lasing THz beam is maneuvered by 25 degrees in emission angle, when the current density changes from 1.9 kA/cm(2) to 2.3 kA/cm(2). A two-dimension (2D) current and mode calculation provides a simple model to explain the behavior of each mode under different bias conditions.
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Chu BF, Zhang Y, Liu HC. [Minimal intervention dentistry: a vision of caries management for older patients. II]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2010; 28:9-12. [PMID: 20337065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Minimal intervention dentistry (MID) is a new approach to caries management in older patients, which emphasize on early discussion, early diagnosis and early treatment. It focuses on stopping the disease process and patient-friendly surgical intervention only when required. Geriatric MID can improve oral ecological balance, lower caries risk, reverse dental caries process and reduce the pain when surgical intervention required. It can help clinicians in coping with erosion, abrasion, demineralization, rampant dental caries, retained roots, recurrent caries, subgingival caries, "wet" oral environment, salivary dysfunction, high plaque levels, swollen or bleeding gum and poor compliance in older patients. This article mainly describes the application of MID in surgical intervention of dental caries, including the strategies for caries removal, cavity preparation, choice of biology material, management of erosion and abrasion, "wet" subgingival environment and vital pulp therapy.
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Xu LL, Liu HC, Wang DS, E LL, Xu L, Jin ZL, Duan YZ. Effects of BMP-2 and dexamethasone on osteogenic differentiation of rat dental follicle progenitor cells seeded on three-dimensional β-TCP. Biomed Mater 2009; 4:065010. [DOI: 10.1088/1748-6041/4/6/065010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Chu BF, Zhang Y, Liu HC. [Minimal intervention dentistry: a vision of caries management for older patients. I]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2009; 27:583-587. [PMID: 20077887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The ageing of Chinese population combined with development of geriatric dentistry results in increased retention of natural teeth and higher risk of dental caries in older patients. This means new challenge for clinicians. Minimal intervention dentistry (MID) is a new approach to caries management in older patients, which emphasize on early discussion, early diagnosis and early treatment. It focuses on stopping the disease process and patient-friendly surgical intervention only when required. This article describes the application of MID in geriatric caries management: Assessment of the risk of caries; early detection (before cavity appears); external and internal remineralization.
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Ma L, Wu X, Ling-Ling E, Wang DS, Liu HC. The transmembrane transport of metformin by osteoblasts from rat mandible. Arch Oral Biol 2009; 54:951-62. [PMID: 19700143 DOI: 10.1016/j.archoralbio.2009.07.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Revised: 07/22/2009] [Accepted: 07/31/2009] [Indexed: 11/26/2022]
Abstract
Previous studies have demonstrated that metformin, one of systemic antihyperglycemic drugs, can slow bone loss caused by diabetes mellitus and has an osteogenic action on osteoblasts in vitro. It is tempting to speculate that metformin would be transported into bone tissues around dental implant by topical administration to improve the bone-implant contact in diabetic patients. In this study, the osteoblasts from rat mandible were cultured with 5.5 mM (control) or 16.5 mM d-glucose, then the uptake of metformin by osteoblasts was detected with high performance liquid chromatography (HPLC). Rat organic cation transporter (rOct) expression was characterized by immunocytochemistry, RT-PCR and Western blotting. It was found that, the uptake of metformin was saturable, Na(+)-dependent, affected by extracellular pH and inhibited by both phenformin and cimetidine (an inhibitor of Octs). rOct1 but no rOct2 was expressed extensively in osteoblasts and the protein level of rOct1 could be up-regulated by metformin. The uptake of metformin and phosphorylated-rOct1 at hyperglycaemic cell culture (16.5 mM d-glucose) significantly increased versus 5.5 mM control (p < 0.05). In conclusion, rat osteoblasts have the ability to transport the metformin intra-cellularly, the uptake of metformin by osteoblasts is a secondary active transportation mediated by rOct1 and high-glucose can improve the uptake of metformin by osteoblasts through phosphorylation of rOct1. The current results suggest that metformin could be used for dental implant topically in type 2 diabetic patients to increase the bone formation, therefore, to enhance the success rate of dental implants clinically.
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Wang CY, Kuznetsova L, Gkortsas VM, Diehl L, Kärtner FX, Belkin MA, Belyanin A, Li X, Ham D, Schneider H, Grant P, Song CY, Haffouz S, Wasilewski ZR, Liu HC, Capasso F. Mode-locked pulses from mid-infrared quantum cascade lasers. OPTICS EXPRESS 2009; 17:12929-43. [PMID: 19654698 DOI: 10.1364/oe.17.012929] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In this study, we report the unequivocal demonstration of midinfrared mode-locked pulses from quantum cascade lasers. The train of short pulses was generated by actively modulating the current and hence the gain of an edge-emitting quantum cascade laser (QCL). Pulses with duration of about 3 ps at full-width-at-half-maxima and energy of 0.5 pJ were characterized using a second-order interferometric autocorrelation technique based on a nonlinear quantum well infrared photodetector. The mode-locking dynamics in the QCLs was modeled based on the Maxwell-Bloch equations in an open two-level system. Our model reproduces the overall shape of the measured autocorrelation traces and predicts that the short pulses are accompanied by substantial wings as a result of strong spatial hole burning. The range of parameters where short mode-locked pulses can be formed is found.
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72
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Schneider H, Liu HC, Winnerl S, Song CY, Walther M, Helm M. Terahertz two-photon quantum well infrared photodetector. OPTICS EXPRESS 2009; 17:12279-12284. [PMID: 19654629 DOI: 10.1364/oe.17.012279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A two-photon detector based on intersubband transitions in GaAs/AlGaAs quantum wells operating in the Terahertz regime below the Reststrahlenband is reported. Resonantly enhanced optical nonlinearities enables sensitive quadratic detection at pJ pulse energies. We demonstrate its use in a quadratic autocorrelator for far-infrared picosecond pulses at around 7 THz.
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73
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Ariyawansa G, Jayaweera PVV, Perera AGU, Matsik SG, Buchanan M, Wasilewski ZR, Liu HC. Normal incidence detection of ultraviolet, visible, and mid-infrared radiation in a single GaAs/AlGaAs device. OPTICS LETTERS 2009; 34:2036-2038. [PMID: 19571991 DOI: 10.1364/ol.34.002036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A GaAs/AlGaAs detector is demonstrated showing multiple detection capabilities. This detector exhibits a broad spectral response in the 200-870 nm (ultraviolet-visible) range for forward bias and in the 590-870 nm (visible) range for reverse bias. In the mid-IR region, two peaks at 5 and 8.9 microm can be observed for low and high forward bias voltages, respectively. In addition, the peak at 8.9 microm is sensitive to the polarization of the incoming radiation.
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Liu HC, Yang XW. [Clinical application of ceramic restoration. IX. Clinical application of ceramic restoration for dental implant]. ZHONGHUA KOU QIANG YI XUE ZA ZHI = ZHONGHUA KOUQIANG YIXUE ZAZHI = CHINESE JOURNAL OF STOMATOLOGY 2009; 44:438-440. [PMID: 19957580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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75
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Zhang L, Liu HC, Wang DS. [Nav1.8 and Nav1.9 mRNA expression in rat trigeminal ganglion at different interval after molar extraction]. ZHONGHUA KOU QIANG YI XUE ZA ZHI = ZHONGHUA KOUQIANG YIXUE ZAZHI = CHINESE JOURNAL OF STOMATOLOGY 2009; 44:301-303. [PMID: 19575990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
OBJECTIVE To observe the expression and function of extraction. METHODS Real-time reverse transcription PCR paralleled with vitro-established cRNA standard curves was applied to measure the expression of Nav1.8, Nav1.9 at 30 min, 2 h, 1 d, 3 d and 6 d respectively after extraction of rat right mandibular molars. The right mandibular molars were used as control. RESULTS Both Nav1.8 and Nav1.9 mRNA in right trigeminal ganglion showed little change after 30 min, and increased slowly after 2 h. Nav1.8, Nav1.9 mRNA expressions increased by 27% and 24.5% respectively compared to the left trigeminal ganglion after 3 d, reaching the highest level (P < 0.05), and then the expressions began decreasing from 6 d. CONCLUSIONS The pain caused by molar extraction is related to the up-regulation of expressions of sodium channels protein Nav1.8 and Nav1.9 mRNA, indicating the participation of sodium channels in regulations of peripheral tissue pain after molar extraction.
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