Publications by authors named "Yiping Zeng"

30 Publications

  • Page 1 of 1

Impact of different control policies for COVID-19 outbreak on the air transportation industry: A comparison between China, the U.S. and Singapore.

PLoS One 2021 16;16(3):e0248361. Epub 2021 Mar 16.

Department of Statistics and Data Science, Southern University of Science and Technology, Shenzhen, People's Republic of China.

Many countries have been implementing various control measures with different strictness levels to prevent the coronavirus disease 2019 (COVID-19) from spreading. With the great reduction in human mobility and daily activities, considerable impacts have been imposed on the global air transportation industry. This study applies a hybrid SARIMA-based intervention model to measure the differences in the impacts of different control measures implemented in China, the U.S. and Singapore on air passenger and air freight traffic. To explore the effect of time span for the measures to be in force, two scenarios are invented, namely a long-term intervention and a short-term intervention, and predictions are made till the end of 2020 for all three countries under both scenarios. As a result, predictive patterns of the selected metrics for the three countries are rather different. China is predicted to have the mildest economic impact on the air transportation industry in this year in terms of air passenger revenue and air cargo traffic, provided that the control measures were prompt and effective. The U.S. would suffer from a far-reaching impact on the industry if the same control measures are maintained. More uncertainties are found for Singapore, as it is strongly associated with international travel demands. Suggestions are made for the three countries and the rest of the world on how to seek a balance between the strictness of control measures and the potential long-term industrial losses.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0248361PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7963044PMC
March 2021

Klotho deficiency aggravates diabetes-induced podocyte injury due to DNA damage caused by mitochondrial dysfunction.

Int J Med Sci 2020 28;17(17):2763-2772. Epub 2020 Sep 28.

University-Town Clinic, 958 hospital of PLA Army, Chongqing, 400020, People's Republic of China.

Diabetic nephropathy (DN) is a progressive disease, the main pathogeny of which is podocyte injury inducing glomerular filtration barrier and proteinuria. The occurrence and development of DN could be partly attributed to the reactive oxygen species (ROS) generated by mitochondria. However, research on how mitochondrial dysfunction (MtD) ultimately causes DNA damage is poor. Here, we investigated the influence of Klotho deficiency on high glucose (HG)-induced DNA damage and . First, we found that the absence of Klotho aggravated diabetic phenotypes indicated by podocyte injury accompanied by elevated urea albumin creatinine ratio (UACR), creatinine and urea nitrogen. Then, we further confirmed that Klotho deficiency could significantly aggravate DNA damage by increasing 8-OHdG and reducing OGG1. Finally, we demonstrated Klotho deficiency may promote MtD to promote 8-OHdG-induced podocyte injury. Therefore, we came to a conclusion that Klotho deficiency may promote diabetes-induced podocytic MtD and aggravate 8-OHdG-induced DNA damage by affecting OOG1.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7150/ijms.49690DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7645346PMC
September 2020

Design and application of terahertz metamaterial sensor based on DSRRs in clinical quantitative detection of carcinoembryonic antigen.

Opt Express 2020 May;28(11):16834-16844

The terahertz (THz) metamaterial biosensor has great potential for label-free and rapid specificity testing. Here, we designed two highly sensitive structures to detect the carcinoembryonic antigen (CEA) of the cancer biomarker in early stages. There was about 29 GHz (500 ng/ml) resonance shift for CEA with an insert grate metamaterial, which was consistent with simulation results. Moreover, the concentration of CEA was gained through the relationship between the cancer marker concentration and frequency shift (Δƒ). Our design and detection methods may provide a potential route for the early warning stages of cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OE.393397DOI Listing
May 2020

Access to chiral α-substituted-β-hydroxy arylphosphonates enabled by biocatalytic dynamic reductive kinetic resolution.

Org Biomol Chem 2020 04;18(14):2672-2677

Department of Chemistry, Engineering Center of Catalysis and Synthesis for Chiral Molecules, Fudan University, Shanghai Engineering Research Center of Industrial Asymmetric Catalysis of Chiral Drugs, 220 Handan Road, Shanghai, 200433, P. R. China.

Ketoreductase (KRED)-catalyzed dynamic reductive kinetic resolution (DYRKR) of α-substituted-β-keto arylphosphonates was developed as a generic and stereoselective approach to synthesize chiral α-substituted-β-hydroxy arylphosphonates, with moderate-to-excellent isolated yield (up to 96%), good-to-excellent diastereoselectivity (up to >99 : <1 dr), and excellent enantioselectivity (up to >99% ee) being achieved.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/d0ob00379dDOI Listing
April 2020

Multifunctional Nanographene Oxide for Targeted Gene-Mediated Thermochemotherapy of Drug-resistant Tumour.

Sci Rep 2017 03 8;7:43506. Epub 2017 Mar 8.

State Key Laboratory of Trauma Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing 400038, China.

Drug resistance remains a major challenge for anticancer treatment, and one of the major mechanisms of drug resistance is the overexpression of drug efflux transporters in cancer. A new approach for defeating drug resistance is the use of a co-delivery strategy that utilizes small interfering RNA (siRNA) to silence the expression of efflux transporters together with a suitable anticancer drug for drug-resistant cells. In this work, multifunctional graphene capable of integrating multiple functions in one system was employed as a novel co-delivery system for siRNA and doxorubicin (Dox), as well as for the controlled release of intracellular pH-triggered and heat-triggered Dox. Additionally, it was used as a synergistic therapy based on the photothermal effect of graphene oxide (GO) under near-infrared (NIR) irradiation and the chemotherapeutic effect of Dox. The nanocomplex exhibited high drug and siRNA loading. Furthermore, the dual delivery of siRNA and Dox by folic acid (FA)-conjugated polyethylenimine-modified PEGylated nanographene (PPG-FA/siRNA/Dox) exhibited a satisfactory gene silencing effect as well as efficient intracellular delivery of Dox. Thus, Dox could access the nucleus and induce greater cytotoxicity compared with siRNA-absent delivery systems. Significantly, under irradiation, the combined treatment showed more synergistic effect for overcoming drug resistance compared with chemotherapy effect alone.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep43506DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5341118PMC
March 2017

Albumin-Mediated Biomineralization of Shape-Controllable and Biocompatible Ceria Nanomaterials.

ACS Appl Mater Interfaces 2017 Mar 13;9(8):6839-6848. Epub 2017 Feb 13.

Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, Department of Preventive Medicine, Third Military Medical University , Chongqing, 400038, China.

Although ceria-based nanostructures have emerged as fascinating materials with diverse biological activities, developing a facile, rapid, and biocompatible method of their preparation remains a major challenge. Herein we describe bovine serum albumin (BSA) protein-directed synthesis of ceria-based nanostructures, including ceria nanoclusters (CNLs), nanoparticles (CNPs), and nanochains (CNHs). Their preparation is simple, one-pot, and performed in a mild reaction condition with a "green" synthetic approach. Most importantly, these three kinds of ceria-based nanostructures can be synthesized in a shape and size controllable manner by tuning the reaction time, temperature, and molar ratio. The formation mechanism shows that growth of these ceria nanostructures is mediated by Ce/Ce switchable redox system, reducible disulfide bonds, and unique spatial structures in albumin proteins. More importantly, these albumin-based ceria nanostructures exhibit high superoxide dismutase (SOD) mimetic activity and good biocompatibility, providing a promising prospect in biomedical application.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsami.6b15442DOI Listing
March 2017

Differential protein expression in metallothionein protection from depleted uranium-induced nephrotoxicity.

Sci Rep 2016 12 14;6:38942. Epub 2016 Dec 14.

State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, No. 30 Gaotanyan Street, Shapingba District, Chongqing, 400038, China.

The purpose of this study was to investigate the underlying mechanism of metallothionein (MT) protection from depleted uranium (DU) using a proteomics approach to search for a DU toxicity-differential protein. MT-/- and MT+/+ mice were administrated with a single dose of DU (10 mg/kg, i.p.) or equal volume of saline. After 4 days, protein changes in kidney tissues were evaluated using a proteomics approach. A total of 13 differentially expressed proteins were identified using two-dimensional electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The validating results showed that the expression of aminoacylase-3 (ACY-3) and the mitochondrial ethylmalonic encephalopathy 1 (ETHE1) decreased significantly after DU exposure; in addition, the reduction in MT-/- mice was more significant than that in MT+/+ mice. The results also showed that exogenous ETHE1 or ACY-3 could increase the survival rate of human embryonic kidney 293 (HEK293) cells after DU exposure. A specific siRNA of ETHE1 significantly increased cell apoptosis rates after DU exposure, whereas exogenous ETHE1 significantly decreased cell apoptosis rates. In summary, ACY-3 and ETHE1 might involve in protection roles of MT. ETHE1 could be a new sensitive molecular target of DU-induced cell apoptosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep38942DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5155243PMC
December 2016

Ghrelin accelerates wound healing in combined radiation and wound injury in mice.

Exp Dermatol 2017 02;26(2):186-193

Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, China.

Impaired wound healing caused by radiation happens frequently in clinical practice, and the exact mechanisms remain partly unclear. Various countermeasures have been taken to tackle with this issue. Ghrelin was considered as a potent endogenous growth hormone-releasing peptide, and its role in enhancing wound repair and regeneration was firstly investigated in whole-body irradiated (γ-ray) mice in this study. Collagen deposition and neovascularization were mostly discussed. The results demonstrated that ghrelin administration promoted cutaneous wound healing in irradiated mice, followed with reduced average wound closure time, increased spleen index (SI) and improved haematopoiesis. After isolation and analysis of granulation tissues in combined radiation and wound injury (CRWI) mice treated with and without ghrelin, a phenomenon of increased DNA, hexosamine, nitrate and nitrite synthesis, elevated collagen content and enhanced neovascularization was observed after ghrelin treatment. Western blotting indicated that ghrelin also increased the expression of vascular endothelial growth factor (VEGF) and transforming growth factor-β (TGF-β), both responsible for wound healing. However, previous administration of growth hormone secretagogue receptor 1a (GHS-R1a) blocker blunted these therapeutic effects of ghrelin on CRWI mice. Our results identify ghrelin as a novel peptide that could be used for radiation-induced impaired wound healing.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/exd.13224DOI Listing
February 2017

Multifunctional Photosensitizer Grafted on Polyethylene Glycol and Polyethylenimine Dual-Functionalized Nanographene Oxide for Cancer-Targeted Near-Infrared Imaging and Synergistic Phototherapy.

ACS Appl Mater Interfaces 2016 Jul 29;8(27):17176-86. Epub 2016 Jun 29.

Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, Department of Preventive Medicine, Third Military Medical University , Chongqing 400038, China.

The integration of photodynamic therapy (PDT) with photothermal therapy (PTT) offers improved efficacy in cancer phototherapy. Herein, a PDT photosensitizer (IR-808) with cancer-targeting ability and near-infrared (NIR) sensitivity was chemically conjugated to both polyethylene glycol (PEG)- and branched polyethylenimine (BPEI)-functionalized nanographene oxide (NGO). Because the optimal laser wavelength (808 nm) of NGO for PTT is consistent with that of IR-808 for PDT, the IR-808-conjugated NGO sheets (NGO-808, 20-50 nm) generated both large amounts of reactive oxygen species (ROS) and local hyperthermia as a result of 808 nm laser irradiation. With PEG- and BPEI-modified NGO as the carrier, the tumor cellular uptake of NGO-808 exhibited higher efficacy than that of strongly hydrophobic free IR-808. Through evaluation with both human and mouse cancer cells, NGO-808 was demonstrated to provide significantly enhanced PDT and PTT effects compared to individual PDT using IR-808 or PTT using NGO. Furthermore, NGO-808 preferentially accumulated in cancer cells as mediated by organic-anion transporting polypeptides (OATPs) overexpressed in many cancer cells, providing the potential for highly specific cancer phototherapy. Using the targeting ability of NGO-808, in vivo NIR fluorescence imaging enabled tumors and their margins to be clearly visualized at 48 h after intravenous injection, providing a theranostic platform for imaging-guided cancer phototherapy. Remarkably, after a single injection of NGO-808 and 808 nm laser irradiation for 5 min, the tumors in two tumor xenograft models were ablated completely, and no tumor recurrence was observed. After treatment with NGO-808, no obvious toxicity was detected in comparison to control groups. Thus, high-performance cancer phototherapy with minimal side effects was afforded from synergistic PDT/PTT treatment and cancer-targeted accumulation of NGO-808.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsami.6b05383DOI Listing
July 2016

Ghrelin accelerates wound healing through GHS-R1a-mediated MAPK-NF-κB/GR signaling pathways in combined radiation and burn injury in rats.

Sci Rep 2016 06 7;6:27499. Epub 2016 Jun 7.

Institute of Combined Injury, State Key Laboratory of Trauma, Burns and Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine, Third Military Medical University, Chongqing, 400038, China.

The therapeutic effect of ghrelin on wound healing was assessed using a rat model of combined radiation and burn injury (CRBI). Rat ghrelin, anti-rat tumor necrosis factor (TNF) α polyclonal antibody (PcAb), or selective antagonists of p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK), and growth hormone secretagogue receptor (GHS-R) 1a (SB203580, SP600125, and [D-Lys3]-GHRP-6, respectively), were administered for seven consecutive days. Levels of various signaling molecules were assessed in isolated rat peritoneal macrophages. The results showed that serum ghrelin levels and levels of macrophage glucocorticoid receptor (GR) decreased, while phosphorylation of p38MAPK, JNK, and p65 nuclear factor (NF) κB increased. Ghrelin inhibited the serum induction of proinflammatory mediators, especially TNF-α, and promoted wound healing in a dose-dependent manner. Ghrelin treatment decreased phosphorylation of p38MAPK, JNK, and p65NF-κB, and increased GR levels in the presence of GHS-R1a. SB203580 or co-administration of SB203580 and SP600125 decreased TNF-α level, which may have contributed to the inactivation of p65NF-κB and increase in GR expression, as confirmed by western blotting. In conclusion, ghrelin enhances wound recovery in CRBI rats, possibly by decreasing the induction of TNF-α or other proinflammatory mediators that are involved in the regulation of GHS-R1a-mediated MAPK-NF-κB/GR signaling pathways.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep27499DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4895129PMC
June 2016

Surface Evolution of Nano-Textured 4H-SiC Homoepitaxial Layers after High Temperature Treatments: Morphology Characterization and Graphene Growth.

Nanomaterials (Basel) 2015 Sep 18;5(3):1532-1543. Epub 2015 Sep 18.

Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083, China.

Nano-textured 4H-SiC homoepitaxial layers (NSiCLs) were grown on 4H-SiC(0001) substrates using a low pressure chemical vapor deposition technique (LPCVD), and subsequently were subjected to high temperature treatments (HTTs) for investigation of their surface morphology evolution and graphene growth. It was found that continuously distributed nano-scale patterns formed on NSiCLs which were about submicrons in-plane and about 100 nanometers out-of-plane in size. After HTTs under vacuum, pattern sizes reduced, and the sizes of the remains were inversely proportional to the treatment time. Referring to Raman spectra, the establishment of multi-layer graphene (MLG) on NSiCL surfaces was observed. MLG with ² disorders was obtained from NSiCLs after a high temperature treatment under vacuum at 1700 K for two hours, while MLG without ² disorders was obtained under Ar atmosphere at 1900 K.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/nano5031532DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5304623PMC
September 2015

Fast responsive and highly efficient optical upconverter based on phosphorescent OLED.

ACS Appl Mater Interfaces 2014 Nov 23;6(21):19011-6. Epub 2014 Oct 23.

Key Laboratory of Semiconductor Materials Science, Institute of semiconductors, Chinese Academy of Sciences , Beijing, China.

In this work, an organic-inorganic hybrid optical upconverter that can convert irradiated 980 nm IR light to 510 nm green phosphorescence sensitively was fabricated and studied. fac-Tris(2-phenylpyridine) iridium (Ir(ppy)3) doped 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP) was used as emitting layer in the phosphorescent organic light-emitting diode (OLED) unit. The upconverter using a phosphorescent OLED as display unit can achieve a higher upconversion efficiency and a low power consumption when compared with the one using fluorescent. An upconversion efficiency of 4.8% can be achieved for phosphorescent device at 15 V, much higher than that of fluorescent one (2.0%). The upconverter's transient optical and electric response to IR pulse were also investigated for the first time. The response time was found to be influenced by IR intensity and applied voltage. It has a response time as short as 60 μs. The rapid response property of the upconverter makes it feasible to be applied to high-speed IR imaging systems.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/am504721gDOI Listing
November 2014

Efficiency enhancement of homoepitaxial InGaN/GaN light-emitting diodes on free-standing GaN substrate with double embedded SiO2 photonic crystals.

Opt Express 2014 Jun;22 Suppl 4:A1093-100

Homoepitaxially grown InGaN/GaN light emitting diodes (LEDs) with SiO2 nanodisks embedded in n-GaN and p-GaN as photonic crystal (PhC) structures by nanospherical-lens photolithography are presented and investigated. The introduction of SiO2 nanodisks doesn't produce the new dislocations and doesn't also result in the electrical deterioration of PhC LEDs. The light output power of homoepitaxial LEDs with embedded PhC and double PhC at 350 mA current is increased by 29.9% and 47.2%, respectively, compared to that without PhC. The corresponding light radiation patterns in PhC LEDs on GaN substrate show a narrow beam shape due to strong guided light extraction, with a view angle reduction of about 30°. The PhC LEDs are also analyzed in detail by finite-difference time-domain simulation (FDTD) to further reveal the emission characteristics.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OE.22.0A1093DOI Listing
June 2014

Efficiency improvement by polarization-reversed electron blocking structure in GaN-based Light-emitting diodes.

Opt Express 2014 May;22 Suppl 3:A1001-8

Polarization-reversed electron-blocking structure, which had negative polarization charges localized at the interface between the last quantum barrier (LQB) and electron-blocking layer (EBL), was demonstrated to remarkably improve the light-emitting efficiency of GaN-based blue light-emitting diodes (LEDs) numerically and experimentally. The improvement was attributed to the enhanced electron-blocking effectiveness by the elevated conduction band nearby the LQB/EBL interface. Nevertheless, the efficiency droop was not mitigated because the decrease of electron-leakage was accompanied by the increase of Auger recombination.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OE.22.0A1001DOI Listing
May 2014

Isolation of human lymphatic malformation endothelial cells, their in vitro characterization and in vivo survival in a mouse xenograft model.

Angiogenesis 2014 Jan 25;17(1):1-15. Epub 2013 Jul 25.

O'Brien Institute, 42 Fitzroy Street, Fitzroy, VIC, 3065, Australia,

Human lymphatic vascular malformations (LMs), also known as cystic hygromas or lymphangioma, consist of multiple lymphatic endothelial cell-lined lymph-containing cysts. No animal model of this disease exists. To develop a mouse xenograft model of human LM, CD34(Neg)CD31(Pos) LM lymphatic endothelial cells (LM-LEC) were isolated from surgical specimens and compared to foreskin CD34(Neg)CD31(Pos) lymphatic endothelial cells (LECs). Cells were implanted into a mouse tissue engineering model for 1, 2 and 4 weeks. In vitro LM-LECs showed increased proliferation and survival under starvation conditions (P < 0.0005 at 48 h, two-way ANOVA), increased migration (P < 0.001, two-way ANOVA) and formed fewer (P = 0.029, independent samples t test), shorter tubes (P = 0.029, independent samples t test) than foreskin LECs. In vivo LM-LECs implanted into a Matrigel™-containing mouse chamber model assembled to develop vessels with dilated cystic lumens lined with flat endothelium, morphology similar to that of clinical LMs. Human foreskin LECs failed to survive implantation. In LM-LEC implanted chambers the percent volume of podoplanin(Pos) vessels was 1.18 ± 2.24 % at 1 week, 6.34 ± 2.68 % at 2 weeks and increasing to 7.67 ± 3.60 % at 4 weeks. In conclusion, the significantly increased proliferation, migration, resistance to apoptosis and decreased tubulogenesis of LM-LECs observed in vitro is likely to account for their survival and assembly into stable LM-like structures when implanted into a mouse vascularised chamber model. This in vivo xenograft model will provide the basis of future studies of LM biology and testing of potential pharmacological interventions for patients with lymphatic malformations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10456-013-9371-8DOI Listing
January 2014

Growth of Hexagonal Columnar Nanograin Structured SiC Thin Films on Silicon Substrates with Graphene-Graphitic Carbon Nanoflakes Templates from Solid Carbon Sources.

Materials (Basel) 2013 Apr 16;6(4):1543-1553. Epub 2013 Apr 16.

Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.

We report a new method for growing hexagonal columnar nanograin structured silicon carbide (SiC) thin films on silicon substrates by using graphene-graphitic carbon nanoflakes (GGNs) templates from solid carbon sources. The growth was carried out in a conventional low pressure chemical vapor deposition system (LPCVD). The GGNs are small plates with lateral sizes of around 100 nm and overlap each other, and are made up of nanosized multilayer graphene and graphitic carbon matrix (GCM). Long and straight SiC nanograins with hexagonal shapes, and with lateral sizes of around 200-400 nm are synthesized on the GGNs, which form compact SiC thin films.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ma6041543DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5452306PMC
April 2013

Improved efficiency of organic/inorganic hybrid near-infrared light upconverter by device optimization.

ACS Appl Mater Interfaces 2012 Sep 6;4(9):4976-80. Epub 2012 Sep 6.

Material Science Center, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing, 100083, People's Republic of China.

An organic/inorganic hybrid up-conversion device was demonstrated in this work, which can convert near-infrared light (NIR) to visible green at high conversion efficiency. The upconverter was fabricated by integrating an In(0.12)Ga(0.88)As/GaAs multiquantum wells (MQWs) photodetector (PD) with an organic light emitting diode (OLED). The up-conversion efficiency of 4.0 W/W % was obtained at 20 V under NIR illumination of 1 mW/mm(2) at room temperature by optimizing the structure of the PD unit and adding MoO(3) doped perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) as interfacial layer of OLED. Meanwhile, the green light output induced by NIR achieved 6050 cd/m(2), which proves that the organic/inorganic hybrid upconverter an excellent candidate that can be applied in light converter field.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/am301340pDOI Listing
September 2012

Vascular endothelial growth factor receptor-3 directly interacts with phosphatidylinositol 3-kinase to regulate lymphangiogenesis.

PLoS One 2012 22;7(6):e39558. Epub 2012 Jun 22.

Centre for Cancer Research, Monash Institute of Medical Research, Monash University, Melbourne, Victoria, Australia.

Background: Dysfunctional lymphatic vessel formation has been implicated in a number of pathological conditions including cancer metastasis, lymphedema, and impaired wound healing. The vascular endothelial growth factor (VEGF) family is a major regulator of lymphatic endothelial cell (LEC) function and lymphangiogenesis. Indeed, dissemination of malignant cells into the regional lymph nodes, a common occurrence in many cancers, is stimulated by VEGF family members. This effect is generally considered to be mediated via VEGFR-2 and VEGFR-3. However, the role of specific receptors and their downstream signaling pathways is not well understood.

Methods And Results: Here we delineate the VEGF-C/VEGF receptor (VEGFR)-3 signaling pathway in LECs and show that VEGF-C induces activation of PI3K/Akt and MEK/Erk. Furthermore, activation of PI3K/Akt by VEGF-C/VEGFR-3 resulted in phosphorylation of P70S6K, eNOS, PLCγ1, and Erk1/2. Importantly, a direct interaction between PI3K and VEGFR-3 in LECs was demonstrated both in vitro and in clinical cancer specimens. This interaction was strongly associated with the presence of lymph node metastases in primary small cell carcinoma of the lung in clinical specimens. Blocking PI3K activity abolished VEGF-C-stimulated LEC tube formation and migration.

Conclusions: Our findings demonstrate that specific VEGFR-3 signaling pathways are activated in LECs by VEGF-C. The importance of PI3K in VEGF-C/VEGFR-3-mediated lymphangiogenesis provides a potential therapeutic target for the inhibition of lymphatic metastasis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0039558PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3382126PMC
November 2012

Dependence of the electrical and optical properties on growth interruption in AlAs/In0.53Ga0.47As/InAs resonant tunneling diodes.

Nanoscale Res Lett 2011 Nov 23;6(1):603. Epub 2011 Nov 23.

Key Laboratory of Semiconductor Materials Science, Chinese Academy of Sciences, P, O, Box 912, Beijing, 100083, People's Republic of China.

The dependence of interface roughness of pseudomorphic AlAs/In0.53Ga0.47As/InAs resonant tunneling diodes [RTDs] grown by molecular beam epitaxy on interruption time was studied by current-voltage [I-V] characteristics, photoluminescence [PL] spectroscopy, and transmission electron microscopy [TEM]. We have observed that a splitting in the quantum-well PL due to island formation in the quantum well is sensitive to growth interruption at the AlAs/In0.53Ga0.47As interfaces. TEM images also show flatter interfaces with a few islands which only occur by applying an optimum value of interruption time. The symmetry of I-V characteristics of RTDs with PL and TEM results is consistent because tunneling current is highly dependent on barrier thickness and interface roughness.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/1556-276X-6-603DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3238496PMC
November 2011

Conserved signaling through vascular endothelial growth (VEGF) receptor family members in murine lymphatic endothelial cells.

Exp Cell Res 2011 Oct 2;317(17):2397-407. Epub 2011 Aug 2.

Centre for Cancer Research, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia.

Lymphatic vessels guide interstitial fluid, modulate immune responses by regulating leukocyte and antigen trafficking to lymph nodes, and in a cancer setting enable tumor cells to track to regional lymph nodes. The aim of the study was to determine whether primary murine lymphatic endothelial cells (mLECs) show conserved vascular endothelial growth factor (VEGF) signaling pathways with human LECs (hLECs). LECs were successfully isolated from murine dermis and prostate. Similar to hLECs, vascular endothelial growth factor (VEGF) family ligands activated MAPK and pAkt intracellular signaling pathways in mLECs. We describe a robust protocol for isolation of mLECs which, by harnessing the power of transgenic and knockout mouse models, will be a useful tool to study how LEC phenotype contributes to alterations in lymphatic vessel formation and function.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.yexcr.2011.07.023DOI Listing
October 2011

Improving light extraction of InGaN-based light emitting diodes with a roughened p-GaN surface using CsCl nano-islands.

Opt Express 2011 Jan;19(2):1065-71

Semiconductor Lighting Technology Research and Development Center, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, China.

InGaN-based light emitting diodes (LEDs) with a top nano-roughened p-GaN surface are fabricated using self-assembled CsCl nano-islands as etch masks. Following formation of hemispherical GaN nano-island arrays, electroluminescence (EL) spectra of roughened LEDs display an obvious redshift due to partial compression release in quantum wells through Inductively Coupled Plasma (ICP) etching. At a 350-mA current, the enhancement of light output power of LEDs subjected to ICP treatment with durations of 50, 150 and 250 sec compared with conventional LED have been determined to be 9.2, 70.6, and 42.3%, respectively. Additionally, the extraction enhancement factor can be further improved by increasing the size of CsCl nano-island. The economic and rapid method puts forward great potential for high performance lighting devices.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OE.19.001065DOI Listing
January 2011

Inhibition of Functional Hyaluronan-CD44 Interactions in CD133-positive Primary Human Ovarian Carcinoma Cells by Small Hyaluronan Oligosaccharides.

Clin Cancer Res 2009 Dec;15(24):7593-7601

Authors' Affiliation: Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, South Carolina.

PURPOSE: CD44 is one of the most common markers used for identification of highly tumorigenic subpopulations of human carcinoma cells, but little is known about the function of CD44 or its major ligand, hyaluronan, in these cells. The purpose of this study was to investigate the involvement of hyaluronan and its interaction with CD44 in the properties of a tumorigenic subpopulation of primary ovarian carcinoma cells. EXPERIMENTAL DESIGN: A tumorigenic subpopulation was identified in ascites fluids from ovarian carcinoma patients by expression of high CD133 levels. Treatment with small hyaluronan oligosaccharides, which dissociate constitutive hyaluronan polymer-CD44 interactions, was used to test the importance of hyaluronan-CD44 interaction in assembly of multidrug and monocarboxylate transporters and receptor tyrosine kinases in the plasma membrane of cells with high CD133 levels, and in the tumorigenic capacity of the CD133-high subpopulation. RESULTS: Although total CD44 levels were similar in cells with high or low CD133 expression, CD44 was present in close association with transporters, receptor tyrosine kinases, and emmprin (CD147) in the plasma membrane of cells with high CD133 levels. Treatment with small hyaluronan oligosaccharides reduced association of the transporters and receptor tyrosine kinases with CD44 in the plasma membrane, diminished drug transporter activity, and inhibited i.p. tumorigenesis in these cells. CONCLUSIONS: We conclude that hyaluronan-CD44 interaction plays an important role in the properties of highly tumorigenic cells by stabilizing oncogenic complexes in their plasma membrane, and that treatment with hyaluronan-CD44 antagonists provides a logical therapeutic approach for abrogating the properties of these cells. (Clin Cancer Res 2009;15(24):7593-601).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1158/1078-0432.CCR-09-2317DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2794991PMC
December 2009

Annealing study of carrier concentration in gradient-doped GaAs/GaAlAs epilayers grown by molecular beam epitaxy.

Appl Opt 2009 Mar;48(9):1715-20

Institute of Electronic Engineering and Optoelectronic Technology, Nanjing University of Science and Technology, Nanjing 210094, China.

We measured the carrier concentration distribution of gradient-doped GaAs/GaAlAs epilayers grown by molecular beam epitaxy before and after annealing at 600 degrees C, using electrochemical capacitance voltage profiling, to investigate the internal variation of transmission-mode GaAs photocathodes arising from the annealing process. The results show that the carrier concentration increased after annealing. As a result, the total band-bending energy in the gradient-doped GaAs emission layer increased by 25.24% after annealing, which improves the photoexcited electron movement toward the surface. On the other hand, the annealing process resulted in a worse carrier concentration discrepancy between the GaAs and the GaAlAs, which causes a lower back interface potential barrier, decreasing the amount of high-energy photoelectrons.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/ao.48.001715DOI Listing
March 2009

The adhesion molecule L1 regulates transendothelial migration and trafficking of dendritic cells.

J Exp Med 2009 Mar 9;206(3):623-35. Epub 2009 Mar 9.

The FIRC Institute of Molecular Oncology, 20139 Milan, Italy.

The adhesion molecule L1, which is extensively characterized in the nervous system, is also expressed in dendritic cells (DCs), but its function there has remained elusive. To address this issue, we ablated L1 expression in DCs of conditional knockout mice. L1-deficient DCs were impaired in adhesion to and transmigration through monolayers of either lymphatic or blood vessel endothelial cells, implicating L1 in transendothelial migration of DCs. In agreement with these findings, L1 was expressed in cutaneous DCs that migrated to draining lymph nodes, and its ablation reduced DC trafficking in vivo. Within the skin, L1 was found in Langerhans cells but not in dermal DCs, and L1 deficiency impaired Langerhans cell migration. Under inflammatory conditions, L1 also became expressed in vascular endothelium and enhanced transmigration of DCs, likely through L1 homophilic interactions. Our results implicate L1 in the regulation of DC trafficking and shed light on novel mechanisms underlying transendothelial migration of DCs. These observations might offer novel therapeutic perspectives for the treatment of certain immunological disorders.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1084/jem.20081211DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2664975PMC
March 2009

Mechanical Deformation Behavior of Nonpolar GaN Thick Films by Berkovich Nanoindentation.

Nanoscale Res Lett 2009 Jul 25;4(7):753-7. Epub 2009 Apr 25.

In this study, the deformation mechanisms of nonpolar GaN thick films grown on m-sapphire by hydride vapor phase epitaxy (HVPE) are investigated using nanoindentation with a Berkovich indenter, cathodoluminescence (CL), and Raman microscopy. Results show that nonpolar GaN is more susceptible to plastic deformation and has lower hardness than c-plane GaN. After indentation, lateral cracks emerge on the nonpolar GaN surface and preferentially propagate parallel to the ⟨112̄0⟩ orientation due to anisotropic defect-related stresses. Moreover, the quenching of CL luminescence can be observed to extend exclusively out from the center of the indentations along the ⟨112̄0⟩ orientation, a trend which is consistent with the evolution of cracks. The recrystallization process happens in the indented regions for the load of 500 mN. Raman area mapping indicates that the distribution of strain field coincides well with the profile of defect-expanded dark regions, while the enhanced compressive stress mainly concentrates in the facets of the indentation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11671-009-9310-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2893916PMC
July 2009

Comparison between gradient-doping GaAs photocathode and uniform-doping GaAs photocathode.

Appl Opt 2007 Oct;46(28):7035-9

Department of Electronic Engineering, East China Institute of Technology, Jiangxi, China.

We compared two reflection-mode negative electron affinity (NEA) GaAs photocathode samples that are grown by molecular beam epitaxy with p-type beryllium doping. One sample is uniform doping, and another is gradient doping. Experimental curves of spectral response sensitivity and quantum efficiency are obtained. The thicknesses of the two cathodes are both 2.6 microm. The integrated sensitivity of the uniform doping one is 1966 microA/lm, and that of the gradient-doping one is 2421 microA/lm. The escape probability and diffusion length are fitted from the spectral response curves. For the uniform-doping sample, the escape probability is 0.45 and the diffusion length is 5 microm. For the gradient-doping sample, the escape probability is 0.55 and the diffusion length is 5.5 microm.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/ao.46.007035DOI Listing
October 2007

Tumor-induced activation of lymphatic endothelial cells via vascular endothelial growth factor receptor-2 is critical for prostate cancer lymphatic metastasis.

Cancer Res 2006 Oct;66(19):9566-75

Bernard O'Brien Institute of Microsurgery, Department of Surgery, University of Melbourne, Parkville, Victoria, Australia.

Prostate cancer disseminates initially and primarily to regional lymph nodes. However, the nature of interactions between tumor cells and lymphatic endothelial cells (LEC) is poorly understood. In the current study, we have isolated prostate LECs and developed a series of two-dimensional and three-dimensional in vitro coculture systems and in vivo orthotopic prostate cancer models to investigate the interactions of prostate cancer cells with prostate LECs. In vitro, highly lymph node metastatic prostate cancer cell lines (PC-3 and LNCaP) and their conditioned medium enhanced prostate LEC tube formation and migration, whereas poorly lymph node metastatic prostate cancer cells (DU145) or normal prostate epithelial cells (RWPE-1) or their conditioned medium had no effect. In vivo, the occurrence of lymphatic invasion and lymph node metastasis was observed in PC-3 and LNCaP xenografts but not in DU145 xenografts. Furthermore, vascular endothelial growth factor (VEGF) receptor (VEGFR)-2 is expressed by prostate LECs, and its ligands VEGF-A, VEGF-C, and VEGF-D are up-regulated in highly lymph node metastatic prostate cancer cells. Recombinant VEGF-A and VEGF-C, but not VEGF-C156S, potently promoted prostate LEC tube formation, migration, and proliferation in vitro, indicating that signaling via VEGFR-2 rather than VEGFR-3 is involved in these responses. Consistent with this, blockade of VEGFR-2 significantly reduced tumor-induced activation of LECs. These results show that the interaction of prostate tumor cells with LECs via VEGFR-2 modulates LEC behavior and is related to the ability of tumor cells to form lymph node metastases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1158/0008-5472.CAN-06-1488DOI Listing
October 2006

Lymphatics in the alimentary tract of children in health and disease: study on mucosal biopsies using the monoclonal antibody d2-40.

Pediatr Dev Pathol 2005 Sep-Oct;8(5):541-9. Epub 2005 Oct 5.

Bernard O'Brien Institute of Microsurgery, Fitzroy Street, Fitzroy, VIC, 3065, Australia.

Primary intestinal lymphangiectasia and intestinal lymphatic hypoplasia are 2 causes of protein-losing enteropathy in children and share many common clinical features. For the diagnosis of lymphatic hypoplasia on endoscopic biopsies of the intestine, i.e., based on a negative finding in a small specimen, a very sensitive and specific method for identifying lymphatics is essential. In the present study, lymphatic vessels were labelled using D2-40 immunostaining in mucosal biopsy specimens of the alimentary tract of children in whom no histologic abnormality was noted and of those who had different relatively common pediatric conditions, including inflammatory and neoplastic diseases. Using this method, lymphatic vessels were well visualized even in young infants and not destroyed by diseases. The presence of the muscularis mucosae in specimens was important for adequate assessment. In the duodenum and esophagus, lymphatics were observed in every single section; in the stomach, ileum, and colon, they were less regular and several sections were sometimes required. The extreme sensitivity of this method for demonstrating lymphatic vessels in the duodenum makes it ideal for the histologic diagnosis of intestinal lymphatic hypoplasia. In 4 patients who were considered to have this diagnosis based on clinical features, full-thickness intestinal biopsies and electron microscopy, D2-40 immunostaining confirmed the absence or marked paucity of lymphatics.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10024-005-0023-xDOI Listing
December 2005

Lymphatic vessel density and lymph node metastasis in prostate cancer.

Prostate 2005 Nov;65(3):222-30

Bernard O'Brien Institute of Microsurgery, Melbourne, Australia.

Background: Few data are available examining the significance of prostatic lymphatic vessel density (LVD) to lymph node metastasis in patients with prostate cancer. The purpose of this study was to determine the distribution of lymphatic vessels in non-carcinomatous prostate tissue, and investigate the relationship between LVD and lymph node status in prostate cancer.

Methods: LVD, identified by D2-40 immunostaining, was evaluated in non-carcinomatous prostates (n = 7) and prostate cancer (n = 37). The staining pattern of D2-40 was compared with that of another lymphatic vessel marker, vascular endothelial growth factor (VEGF) receptor-3, and a blood vessel endothelial marker, CD34, in adjacent sections.

Results: The D2-40 antigen, podoplanin, was expressed exclusively in lymphatic vessels within tumor and normal tissue in all specimens. There was no overlap between cell staining for D2-40 and CD34. Peritumoral LVD and peritumoral lymphatic invasion were significantly associated with lymph node metastasis. VEGF receptor-3 was expressed in a subset of D2-40+ lymphatic vessels.

Conclusions: We have demonstrated that peritumoral lymphatic vessels are likely to serve as major conduits for nodal metastasis in prostate cancer using D2-40 to decorate lymphatic endothelium marker podoplanin. Lack of coexpression of podoplanin and VEGF receptor-3 in some lymphatic vessels suggests the heterogeneity of lymphatic endothelial cells in prostate tissue.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/pros.20288DOI Listing
November 2005

Expression of vascular endothelial growth factor receptor-3 by lymphatic endothelial cells is associated with lymph node metastasis in prostate cancer.

Clin Cancer Res 2004 Aug;10(15):5137-44

Bernard O'Brien Institute of Microsurgery, Melbourne, Australia.

Purpose: The molecular mechanisms underlying lymph node metastasis are poorly understood, despite the well-established clinical importance of lymph node status in many human cancers. Recently, vascular endothelial growth factor (VEGF)-C and VEGF-D have been implicated in the regulation of tumor lymphangiogenesis and enhancement of lymphatic invasion via activation of VEGF receptor-3. The purpose of this study was to determine the expression pattern of the VEGF-C/VEGF-D/VEGF receptor-3 axis in prostate cancer and its relationship with lymph node metastasis.

Experimental Design: The expression pattern of VEGF-C, VEGF-D, and VEGF receptor-3 in localized prostate cancer specimens (n = 37) was determined using immunohistochemistry.

Results: Widespread, heterogeneous staining for VEGF-C and VEGF-D was observed in all cancer specimens. Intensity of VEGF-C staining was lower in benign prostate epithelium than in adjacent carcinoma, whereas no difference between benign epithelium and carcinoma was observed for VEGF-D staining. VEGF receptor-3 immunostaining was detected in endothelial cells of lymphatic vessels in 18 of 37 tissue samples. The presence of VEGF receptor-3-positive vessels was associated with lymph node metastasis (P = 0.0002), Gleason grade (P < 0.0001), extracapsular extension (P = 0.0382), and surgical margin status (P = 0.0069). In addition, VEGF receptor-3 staining highlighted lymphatic invasion by VEGF-C-positive/VEGF-D-positive carcinoma cells.

Conclusions: Together, these results suggest that paracrine activation of lymphatic endothelial cell VEGF receptor-3 by VEGF-C and/or VEGF-D may be involved in lymphatic metastasis. Thus the VEGF-C/VEGF-D/VEGF receptor-3 signaling pathway may provide a target for antilymphangiogenic therapy in prostate cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1158/1078-0432.CCR-03-0434DOI Listing
August 2004
-->