Two-dimensional ultrathin gold film composed of steadily linked dense nanoparticle with surface plasmon resonance

Background

Noble metallic nanoparticles have prominent optical local-field enhancement and light trapping properties in the visible light region resulting from surface plasmon resonances.

Results

We investigate the optical spectral properties and the surface-enhanced Raman spectroscopy of two-dimensional distinctive continuous ultrathin gold nanofilms. Experimental results show that the one- or two-layer nanofilm obviously increases absorbance in PEDOT:PSS and P3HT:PCBM layers and the gold nanofilm acquires high Raman-enhancing capability.

Conclusions

The fabricated novel structure of the continuous ultrathin gold nanofilms possesses high surface plasmon resonance properties and boasts a high surface-enhanced Raman scattering (SERS) enhancement factor, which can be a robust and cost-efficient SERS substrate. Interestingly, owing to the distinctive morphology and high light transmittance, the peculiar nanofilm can be used in multilayer photovoltaic devices to trap light without affecting the physical thickness of solar photovoltaic absorber layers and yielding new options for solar cell design.     

A quantum dots and superparamagnetic nanoparticle-based method for the detection of HPV DNA

Background

The recent advance in nanomaterial research field prompts the development of diagnostics of infectious diseases greatly. Many nanomaterials have been developed and applied to molecular diagnostics in labs. At present, the diagnostic test of human papillomavirus (HPV) relies exclusively on molecular test. Hereon, we report a rapid and facile quantum dots (QDs) and superparamagnetic nanoparticle-based hybridization assay for the detection of (HPV) 16 infections which combines the merits of superparamagnetic nanoparticles and QDs and wholly differs from a conventional hybridization assay at that the reaction occurs at homogeneous solution, and total time for detection is no more than 1 h.

Methods

The probes were labeled with superparamagnetic nanoparticles and QDs. Sixty cervical swab samples were used to perform a hybridization assay with these probes, and the results were compared with type-specific polymerase chain reaction (PCR) method.

Results

The statistic analysis suggests that there is no significant difference between these two methods. Furthermore, this method is much quicker and easier than the type-specific PCR method.

Conclusion

This study has successfully validated the clinical performance of our hybridization assay. The advantages in the time of detection and ease of process endow this method with great potential in clinical usage, especially mass epidemiological screening.     

Lewis y Regulate Cell Cycle Related Factors in Ovarian Carcinoma Cell RMG-I in Vitro via ERK and Akt Signaling Pathways

Objective

To investigate the effect of Lewis y overexpression on the expression of proliferation-related factors in ovarian cancer cells.

Methods

mRNA levels of cyclins, CDKs, and CKIs were measured in cells before and after transfection with the α1,2-fucosyltransferase gene by real-time PCR, and protein levels of cyclins, CDKs and CKIs were determined in cells before and after gene transfection by Western blot.

Results

Lewis y overexpression led to an increase in both mRNA and protein expression levels of cyclin A, cyclin D1 and cyclin E in ovarian cancer cells, decrease in both mRNA and protein expression levels of p16 and p21, and decrease of p27 at only the protein expression level without change in its mRNA level. There were no differences in proteins and the mRNA levels of CDK2, CDK4 and CDK6 before and after gene transfection. Anti-Lewis y antibody, ERK and PI3K pathway inhibitors PD98059 and {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 reduced the difference in cyclin and CKI expression caused by Lewis y overexpression.

Conclusion

Lewis y regulates the expression of cell cycle-related factors through ERK/MAPK and PI3K/Akt signaling pathways to promote cell proliferation.     

Elevated Levels of Lewis Y and Integrin α5β1 Correlate with Chemotherapeutic Drug Resistance in Epithelial Ovarian Carcinoma

Objective

To measure Lewis y and integrin α₅β₁ expression in epithelial ovarian carcinoma and to correlate the levels of these molecules with ovarian carcinoma chemotherapy and prognosis.

Methods

The study population included 34 ovarian carcinoma patients with chemotherapeutic drug-resistance, six partially drug-sensitive cases, and 52 drug-sensitive cases (92 total). Immunochemistry was used to determine expression of Lewis y antigen and integrin α₅β₁ in ovarian carcinoma tissues, and correlation of these molecules with chemotherapy resistance was further investigated, Multi-factor logistic regression analysis was applied to investigate: age, surgical stage, grade, subtype of patient cases, metastasis of lymph nodes, residual tumor size, expression levels of Lewis y antigen and integrin α₅β₁ correlation with ovarian carcinoma chemotherapy resistance.

Results

The expression rates of Lewis y antigen and integrins α₅ and β₁ were significantly greater in the drug-resistant group (91.17%, 85.29%, 88.24%) than the partially sensitive (50.00%, 33.33%, 50.00%) or sensitive groups (61.54%, 57.69%, 55.77%). Binary logistic regression analysis revealed that surgical stage, residual tumor size, and expression of integrin α₅ and Lewis y in ovarian carcinoma tissues were independent risk factors for chemotherapeutic drug resistance.

Conclusions

Overexpression of Lewis y and integrin α₅ are strong risk factors for chemotherapeutic drug resistance in ovarian carcinoma patients.     

Pilot study: alteration of deleted in liver cancer1 and phosphorylated focal adhesion kinase Y397 cytoplasmic expression and the prognostic value in advanced epithelial ovarian carcinoma

Background

Deletion in liver cancer gene (DLC1) and phosphorylated focal adhesion kinase (p-FAK) have recently been reported as metastasis-related genes. However, the roles and prognostic values of their expression in epithelial ovarian carcinomas (EOCs) remain unclear.

Methods

The expression and prognostic value of DLC1 and p-FAK Y397 in EOC were evaluated by immunohistochemistry and multivariate analysis.

Results

Low expression of DLC1 and high expression of p-FAK Y397 were found in the 76 cases of EOC. The expression of DLC1 and p-FAK Y397 were negatively correlated. Multivariate analysis showed that the combination of them was an independent prognostic marker of EOC (P = 0.0319).

Conclusions

DLC1 and pFAK Y397 had an association with the clinicopathologic characteristics of EOC. Expression of neither of these genes was a prognostic factor alone, but the combination revealed a significant prognostic value in the 60 cases of advanced stage EOC.     

Insulin-producing cells could not mimic the physiological regulation of insulin secretion performed by pancreatic beta cells

Objective

The aim of this study was to compare the difference between insulin-producing cells (IPCs) and normal human pancreatic beta cells both in physiological function and morphological features in cellular level.

Methods

The levels of insulin secretion were measured by enzyme-linked immunosorbent assay. The insulin gene expression was determined by real-time quantitative polymerase chain reaction. The morphological features were detected by atomic force microscopy (AFM) and laser confocal scanning microscopy.

Results

IPCs and normal human pancreatic beta cells were similar to each other under the observation in AFM with the porous structure features in the cytoplasm. Both number of membrane particle size and average roughness of normal human beta cells were higher than those of IPCs.

Conclusions

Our results firstly revealed that the cellular ultrastructure of IPCs was closer to that of normal human pancreatic beta cells, but they still could not mimic the physiological regulation of insulin secretion performed by pancreatic beta cells.     

The Study of the Inhibition of the Recombinant TACE Prodomain to Endotoxemia in Mice

Objective:

To demonstrate the inhibitory function of the prodomain of tumor necrosis factor-α (TNF-α) converting enzyme (TACE) on TACE activity and to develop an approach to interfere with inflammation processes.

Methods:

The cDNA encoding the full-length ectodomain (T1300) and prodomain (T591) of TACE were amplified by RT-PCR. The expression plasmids (pET-28a (+)-T1300 and pET-28a (+)-T591) were constructed and transformed into E. coli BL21. After Ni²⁺-NTA resin affinity chromatography, the recombinant T591 protein was obtained and assayed. In order to detect its inhibiton of TACE activity, the mice in the LPS-induced endotoxemia model group were treated with the recombinant TACE prodomain protein prior to the injection of LPS. Murine peritoneal macrophages were isolated from mice abdominal cavity for FCM and the liver, kidney and lung were removed for traditionally histopathology sectioning.

Results:

The FCM results showed that the recombinant prodomain protein decreased the release of the sTNF-α, which mediated the accumulation of TNF-α on the surface of macrophage cells. HE staining proved that the recombinant protein can decrease the inflammatory response in internal organs of endotoxaemia mice.

Conclusions:

The recombinant prodomain of TACE has the ability to inhibit sTNF-α release, which indicates that prodomain is an effective antagonist of TACE and might be useful in the molecular design of anti-inflammatory drugs.     

The roles of integrin β1 in phenotypic maintenance and dedifferentiation in chondroid cells differentiated from human adipose-derived stem cells

Objective

The aim of this study is to probe the intrinsic mechanism of chondroid cell dedifferentiation in order to provide a feasible solution for this in cell culture.

Methods

Morphological and biomechanical properties of cells undergoing chondrogenic differentiation from human adipose-derived stem cells (ADSCs) were measured at the nanometer scale using atomic force microscopy and laser confocal scanning microscopy. Gene expression was determined by real-time quantitative polymerase chain reaction.

Results

The expression of COL II, SOX9, and Aggrecan mRNA began to increase gradually at the beginning of differentiation and reach a peak similar to that of normal chondrocytes on the 12th day, then dropped to the level of the 6th day at 18th day. Cell topography and mechanics trended resembled those of the genes’ expression. Integrin β1 was expressed in ADSCs and rapidly upregulated during differentiation but downregulated after reaching maturity.

Conclusions

The amount and distribution of integrin β1 may play a critical role in mediating both chondroid cell maturity and dedifferentiation. Integrin β1 is a possible new marker and target for phenotypic maintenance in chondroid cells.     

The Role of Survivin in Podocyte Injury Induced by Puromycin Aminonucleoside

Objective

Survivin is a member of the inhibitor of apoptosis protein family, which uniquely promotes mitosis and regulates apoptosis in cancer cells. Recent studies have demonstrated that survivin also expresses in several normal adult cells. In the present study, we aimed to investigate the function of survivin in the terminally differentiated epithelial cells, podocytes.

Methods

Survivin expression and location were detected by Quantitative Real-Time PCR, western blot and fluorescence confocal microscopy methods in normal and injured mouse podocytes. Cyto-protection function of survivin was also studied in cultured podocyte injured by puromycin aminonucleoside (PAN), transfected with survivin siRNA to down-regulate survivin expression, or with survivin plasmid to transiently over-express survivin.

Results

In podocytes, PAN stimulated expressions of survivin and the apoptosis related molecule caspase 3. Knockdown of survivin expression by siRNA increased the activation of caspase 3, induced podocyte apoptosis and remarkable rearrangement of actin cytoskeleton. Moreover, over-expression of survivin inhibited PAN-induced podocyte apoptosis and cytoskeleton rearrangement.

Conclusion

Our data provides the evidence that survivin plays an important role in protecting podocytes from apoptosis induced by PAN. The mechanism of survivin related anti-apoptosis may, at least partially, be through the activation of caspase 3.     

Relationship between Serum Osteocalcin Levels and Non-Alcoholic Fatty Liver Disease in Adult Males,South China

AIM

To determine serum osteocalcin levels in South Chinese males with non-alcoholic fatty liver disease (NAFLD) and to examine the relation between serum osteocalcin and NAFLD.

METHODS

Data were collected from 1683 men attending the Fangchenggang Area Male Healthy and Examination Survey (FAMHES) from September 2009 to December 2009. Serum osteocalcin was measured with electrochemiluminescence immunoassay. An abdominal ultrasonographic examination for all individuals was performed by two experienced ultrasonographers. The associations of serum osteocalcin with NAFLD were evaluated.

RESULTS

The levels of serum osteocalcin were lower in 364 NAFLD participants than in 1319 non-NAFLD participants (24.51 ± 1.38 ng/mL vs. 20.81 ± 1.33 ng/mL, p < 0.001). Serum osteocalin level was associated with the scale of NAFLD (r = −0.150, p < 0.01). Serum osteocalin level tended to decrease with the scale of NAFLD. Binary logistic regression analysis showed that decreased ORs for NAFLD were observed from the first to the fourth osteocalcin quartiles.

CONCLUSIONS

Our findings suggest that a lower serum osteocalcin level is associated with the presence of NAFLD.     

Application of anodized titanium for enhanced recruitment of endothelial progenitor cells

Objectives

To study the efficacy of an effective anodized titanium surface with enhanced attachment of endothelial progenitor cell (EPC).

Background

In-stent restenosis is a major obstacle for vascular patency after catheter-based intravascular interventions. Recently, stents that capture EPCs have been paid attention in order to make a functional endothelialized layer at the site of stent-induced endothelial denudation. Anodized titanium has been shown to enhance stem cell attachment. Anodization is a quick and inexpensive method, which can provide suitable stent surface.

Methods

Surface topography was examined by high-resolution scanning electron microscopy (SEM). Substrates were co-cultured with EPCs at second passage in 24-well culture plates. Evaluation of cell growth, proliferation, viability, surface cytotoxicity and cell adhesion was performed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test and 4,6-diamidino-2-phenylindole dihydrochloride staining. For platelet attachment, platelets added to substrates were evaluated under SEM.

Results

The average MTT values for tissue culture polystyrene plate, unanodized and anodized titanium with nanostructure were equal to 0.49, 0.16 and 0.72, respectively (P < 0.05). The surface had no cytotoxic effects on cells. The average cell attachment results showed that 9,955 ± 461.18, 3,300 ± 197.98 and 11,359 ± 458.10 EPCs were attached per well of tissue culture polystyrene plate, unanodized and anodized titanium surfaces, respectively (P < 0.05).

Conclusions

Anodized titanium surfaces can be potentially applied for devices that need enhanced recruitment of EPCs. This unique property makes these anodized surfaces good and cheap candidates for designing cardiovascular medical devices as endovascular stents.     

Chemoresistance Is Associated with MUC1 and Lewis y Antigen Expression in Ovarian Epithelial Cancers

Objective

The aim of this study was to analyze the correlation and clinical significance between the expression of Mucin-1 (MUC1) and the Lewis y antigen with chemoresistance in ovarian epithelial cancers.

Methods

Ovarian cancer patients (n = 92) treated at our hospital from May 2005 to July 2009 were divided, according to their treatment and follow-up outcomes, into a resistant group (n = 37) or sensitive group (n = 55). The expression of MUC1 and Lewis y antigen in ovarian cancer tissues was detected using immunohistochemistry and correlated with chemoresistance.

Results

The positive rates of MUC1 and Lewis y antigen in the resistant group were both 91.89%, significantly higher than their positive rates in the sensitive group (65.45% and 69.09%, respectively, and both p < 0.05). MUC1 or Lewis y expression and the pathological stage of the tissue were independent risk factors for chemoresistance (all p < 0.05).

Conclusion

The increased expression of MUC1 and the Lewis y antigen is a significant risk factor for chemoresistance in patients with ovarian epithelial cancer.     

Radiative and nonradiative relaxation phenomena in hydrogen- and oxygen-terminated porous silicon

Abstract

Using time-resolved photoluminescence spectroscopy over a wide range of temperatures, we were able to probe both radiative and nonradiative relaxation processes in luminescent porous silicon. By comparing the photoluminescence decay times from freshly prepared and oxidized porous silicon, we show that radiative processes should be linked with quantum confinement in small Si nanocrystallites and are not affected by oxidation. In contrast, nonradiative relaxation processes are associated with the state of oxidation where slower relaxation times characterize hydrogen-terminated porous silicon. These results are in a good agreement with the extended vibron model for small Si nanocrystallites.

PACS

78.55.Mb; 78.67.Rb; 78.47.jd     

Elevated peripheral blood plasma concentrations of tie-2 and angiopoietin 2 in patients with neuroendocrine tumors

Background

Gastro-entero-pancreatic/neuroendocrine (NET) tumors are highly vascularized neoplasms. However, our knowledge concerning circulating levels of the angiogenic factors in NET patients still remains insufficient.

Methods

The aim of this study was to measure plasma concentrations of VEGF, angiopoietin 1 (Ang-1), angiopoietin 2 (Ang-2), soluble Tie-2, endostatin, osteopontin (OPN) and chromogranin A (CgA) in 36 NET patients and 16 controls.

Results

Only the plasma concentrations of Tie-2 and CgA were higher in NET patients as compared to controls. These levels were within the reference range in controls; however one control demonstrated slightly elevated Tie-2 and 4 elevated CgA. Similarly, in the subgroup of patients with carcinoid syndrome, only Tie-2 and CgA concentrations were higher than those in patients with non-functioning NETs. In turn, in the subgroup of metastatic patients, only Ang-2 levels were higher than in those with localized disease. A positive correlation was found between Ang-2 and Tie-2 levels in metastatic patients and between Ang-1 and Tie-2 in localized NETs.

Conclusions

The plasma concentration of Tie-2 is proposed as an additional marker for NET patients and seems to be similarly effective as the currently used CgA level. Moreover, higher plasma levels of Ang-2 together with the positive correlation between Ang-2 and Tie-2 levels in metastatic subjects, implies that cases with a Tie-2 level above the upper limits, together with higher level of Ang-2 seem to be highly predictive of metastases.     

High spatial resolution mapping of surface plasmon resonance modes in single and aggregated gold nanoparticles assembled on DNA strands

Abstract

We present the mapping of the full plasmonic mode spectrum for single and aggregated gold nanoparticles linked through DNA strands to a silicon nitride substrate. A comprehensive analysis of the electron energy loss spectroscopy images maps was performed on nanoparticles standing alone, dimers, and clusters of nanoparticles. The experimental results were confirmed by numerical calculations using the Mie theory and Gans-Mie theory for solving Maxwell''s equations. Both bright and dark surface plasmon modes have been unveiled.

PACS

78.67.Bf; 61.46.Df; 87.64.Ee     

Color-tunable up-conversion emission in Y2O3:Yb3+, Er3+ nanoparticles prepared by polymer complex solution method

Abstract

Powders of Y₂O₃ co-doped with Yb³⁺ and Er³⁺ composed of well-crystallized nanoparticles (30 to 50 nm in diameter) with no adsorbed ligand species on their surface are prepared by polymer complex solution method. These powders exhibit up-conversion emission upon 978-nm excitation with a color that can be tuned from green to red by changing the Yb³⁺/Er³⁺ concentration ratio. The mechanism underlying up-conversion color changes is presented along with material structural and optical properties.

PACS

42.70.-a, 78.55.Hx, 78.60.-b     

Correlation between matrix structural order and compressive stress exerted on silicon nanocrystals embedded in silicon-rich silicon oxide

Abstract

Silicon nanocrystals embedded in a silicon oxide matrix were deposited by radio frequency reactive magnetron sputtering. By means of Raman spectroscopy, we have found that a compressive stress is exerted on the silicon nanocrystal cores. The stress varies as a function of silicon concentration in the silicon-rich silicon oxide layers varies, which can be attributed to changes of nanocrystal environment. By conducting the Fourier transform infrared absorption experiments, we have correlated the stresses exerted on the nanocrystal core to the degree of matrix structural order.

PACS

78.67.Bf, 78.67.Pt, 73.63.Bd, 78.47.D, 74.25.Nd     

Graphite nanoplatelet chemical cross-linking by elemental sulfur

Abstract

Graphite nanoplatelets (GNPs) react with elemental sulfur to provide a mechanically stable, spongy material characterized by good electrical conductivity and high surface development; such unique property combination makes these novel nanostructured materials very useful for applications in different technological fields. The carbon-sulfur reaction can be accurately investigated by thermal analysis (differential scanning calorimetry and thermogravimetric analysis) and energy-dispersive X-ray spectroscopy combined with scanning electron microscopy. The thermal treatment required for the formation of electrically conductive monosulfur connections among the GNP unities has been investigated.

PACS

81.05.Ue, 81.05.Rm, 81.16.Be     

Combination BMSC and Niaspan Treatment of Stroke Enhances White Matter Remodeling and Synaptic Protein Expression in Diabetic Rats

Objective

White matter remodeling plays an important role in neurological recovery after stroke. Bone marrow stromal cells (BMSCs) and Niaspan, an agent which increases high density lipoprotein (HDL), each induces neurorestorative effects and promotes white matter remodeling after stroke in non-diabetic rats. In this study, we test whether combination of BMSCs with Niaspan induces an enhanced white matter remodeling in the ischemic brain of diabetic rats.

Research design and methods

Type-1 diabetes (T1DM) rats were subjected to transient middle cerebral artery occlusion (MCAo) and treated with or without BMSCs; Niaspan; and the combination of BMSCs + Niaspan daily for 14 days after MCAo. Immunostaining for white matter remodeling and synaptic protein expression including NG2; CNPase; BS (Bielschowsky silver); LFB (luxol fast blue); Synaptophysin and SMI-31 immunostaining were performed.

Results

BMSC monotherapy did not regulate NG2 and CNPase expression compared to T1DM control rats. Both, combination of BMSCs + Niaspan treatment, and Niaspan monotherapy significantly increase NG2 and CNPase expression compared to T1DM control. While combination BMSC+Niaspan, BMSC monotherapy and Niaspan monotherapy groups all increase BS, LFB, synaptophysin, and SMI-31 expression in the ischemic brain compared to T1DM-MCAo control. In addition, the combination treatment significantly enhances LFB, SMI-31, and Synaptophysin expression compared to BMSC monotherapy.

Conclusions

Combination treatment of stroke with BMSCs and Niaspan in T1DM rats increases white matter remodeling and additively increases BMSC monotherapy induced myelination and synaptic plasticity after stroke in T1DM rats.