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ABSTRACT: The resolution of single molecule localization imaging techniques largely depends on the precision of localization algorithms. However, the commonly used Gaussian function is not appropriate for anisotropic dipoles because it is not the true point spread function. We derived the theoretical point spread function of tilted dipoles with restricted mobility and developed an algorithm based on an artificial neural network for estimating the localization, orientation and mobility of individual dipoles. Compared with fitting-based methods, our algorithm demonstrated ultrafast speed and higher accuracy, reduced sensitivity to defocusing, strong robustness and adaptability, making it an optimal choice for both two-dimensional and three-dimensional super-resolution imaging analysis.
Protein & Cell 06/2013;
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ABSTRACT: Anisotropic CdS-AgInS2 nanocrystals are directly grown into benzothiadiazole-based semiconducting
polymer solution. Their nonlinear optical absorption and nonlinear scattering are investigated with
7-ns laser pulses of 532-nm wavelength for optical limiting applications. Optical limiting is found to
be enhanced in the polymer-CdS-AgInS2 nanocomposites, as compared to pure polymer or
CdS-AgInS2 nanocrystals. The observation is explained quantitatively using a numerical model which
includes one-photon-induced excited state absorption, two-photon absorption, and nonlinear scattering.
Presence of charge transfer in polymer-CdS-AgInS2 nanocomposites is found from zero-biased
photoconduction experiments, which plays an important role in the enhancement of nonlinear optical
properties. In addition, it is also demonstrated that these nanocomposite films can be utilized for
photodetection with large and fast photoconductive responses.
Journal of Applied Physics 03/2013; 113:123107-1. · 2.17 Impact Factor
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ABSTRACT: We designed and synthesized amphiphilic oligo(ethylene glycolated) C60-(light-harvesting fluorene antenna) nanostructures C60(>DPAF-EG12C1) by incorporating a donor–acceptor antenna component of C60–DPAF with highly hydrophilic oligo(ethylene glycol) (EGn) side-chains to increase the amphiphilicity of the molecule. The chain length of EGn arms was selected to match with the overall molecular radius and to achieve a balance between the hydrophobicity and hydrophilicity of resulting molecules Molecular self-assembly of C60(>DPAF-EG12C1) forming bilayered fullerosome nanovesicles led to the observation of ultrafast femtosecond nonlinear optical (NLO) absorption characteristics. Two-photon absorption phenomena were found to be the dominating photophysical events showing a large molar concentration-insensitive 2PA cross-section value equivalent to 8500 GM in a form of vesicles, on average, at the estimated effective nanovesicle concentration as low as 5.5 × 10−8 MV (molecular molar concentration of 5.0 × 10−4 M) in H2O.
ECS Transactions; 01/2013
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ABSTRACT: To explore the interaction of Anxa2 with P-Glycoprotein (P-gp) in the migration and invasion of the multidrug-resistant (MDR) human breast cancer cell line MCF-7/ADR.
A pair of short hairpin RNA (shRNA) targeting P-gp was transfected into MCF-7/ADR cells, and monoclonal cell strains were screened. The expression of P-gp was detected by Western blot. Transwell chambers were used to observe the cell migration capacity and invasion ability. The interaction between P-gp and Anxa2 was examined by immunoprecipitation and immunofluorescence confocal microscopy analyses.
P-gp expression was significantly knocked down, and there were notable decreasing trends in the migration and invasion capability of MDR breast cancer cells (P<0.05). There was a close interaction between Anxa2 and P-gp.
MCF-7/ADR is an MDR human breast cancer cell line with high migration and invasion abilities. The knockdown of P-gp notably impaired the migration and invasion abilities of the tumor cells. The interaction of Anxa2 with P-pg may play an important role in the enhanced invasiveness of MDR human breast cancer cells.
Cancer biology & medicine. 06/2012; 9(2):99-104.
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Mingshu Zhang,
Hao Chang,
Yongdeng Zhang,
Junwei Yu,
Lijie Wu, Wei Ji,
Juanjuan Chen,
Bei Liu,
Jingze Lu,
Yingfang Liu,
Junlong Zhang,
Pingyong Xu,
Tao Xu
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ABSTRACT: Monomeric (m)Eos2 is an engineered photoactivatable fluorescent protein widely used for super-resolution microscopy. We show that mEos2 forms oligomers at high concentrations and forms aggregates when labeling membrane proteins, limiting its application as a fusion partner. We solved the crystal structure of tetrameric mEos2 and rationally designed improved versions, mEos3.1 and mEos3.2, that are truly monomeric, are brighter, mature faster and exhibit higher photon budget and label density.
Nature Methods 05/2012; 9(7):727-9. · 19.28 Impact Factor
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ABSTRACT: We demonstrated ultrafast two-photon absorption based energy transfer at femtosecond of bilayered
fullerosome vesicle nanostructures derived from molecular self-assembly of amphiphilic oligo(ethylene
glycolated) C 60 -(light-harvesting diphenylaminofluorene antenna), leading to nonlinear optical characteristics. Fullerene conjugates were designed to enhance photoresponse in a femtosecond time scale by applying an isomerizable periconjugation linker between the C 60 cage and diphenylaminofluorene antenna subunit in an intramolecular contact distance of only < 3.0 Å.
Morphology of C 60 (>DPAF-EG 12 C 1 )-based fullerosome nanovesicles in H 2 O was characterized to consist of a bilayered shell with a sphere diameter of 20−70 nm and a chromophore shell-width of 9.0−10 nm, fitting well with a head-to-head packing configuration of the molecular length. The observed NLO characteristics led to a sharp trend of efficient light-transmittance intensity reduction at the input laser intensity above 100 GW/cm 2 .
221st ECS Meeting, The Electrochemical Society, Washington State Convention Center and the Sheraton Seattle, Seattle, WA, USA.; 05/2012
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Peiqi Zhao,
Hanjie Wang,
Man Yu,
Zhenyu Liao,
Xianhuo Wang,
Fei Zhang, Wei Ji,
Bing Wu,
Jinghua Han,
Haichang Zhang,
Huaqing Wang,
Jin Chang,
Ruifang Niu
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ABSTRACT: A functional drug carrier comprised of folic acid modified lipid-shell and polymer-core nanoparticles (FLPNPs) including poly(D,L-lactide-co-glycolide) (PLGA) core, PEGylated octadecyl-quaternized lysine modified chitosan (PEG-OQLCS) as lipid-shell, folic acid as targeting ligand and cholesterol was prepared and evaluated for targeted delivery of paclitaxel (PTX). Confocal microscopy analysis confirmed the coating of the lipid-shell on the polymer-core. Physicochemical characterizations of FLPNPs, such as particle size, zeta potential, morphology, encapsulation efficiency, and in vitro PTX release, were also evaluated. The internalization efficiency and targeting ability of FLPNPs were demonstrated by flow cytometry and confocal microscopy. PTX loaded FLPNPs showed a significantly higher cytotoxicity than the commercial PTX formulation (Taxol®). The intravenous administration of PTX encapsulated FLPNPs led to tumor regression and improvement of animal survival in a murine model, compared with that observed with Taxol® and biodistribution study showed that PTX concentration in tumor for PTX encapsulated FLPNPs was higher than other PTX formulations. Our data indicate that PTX loaded FLPNPs are a promising nano-sized drug formulation for cancer therapy.
European journal of pharmaceutics and biopharmaceutics: official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V 03/2012; 81(2):248-56. · 3.15 Impact Factor
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ABSTRACT: Current state of the art reconstruction of bony defects in the craniomaxillofacial (CMF) area involves transplantation of autogenous or allogenous bone grafts. However, the inherent drawbacks of this approach strongly urge clinicians and researchers to explore alternative treatment options. Currently, a wide interest exists in local delivery of biomolecules from synthetic biomaterials for CMF bone regeneration, in which small biomolecules are rapidly emerging in recent years as an interesting adjunct for upgrading the clinical treatment of CMF bone regeneration under compromised healing conditions. This review highlights recent advances in the local delivery small and large biomolecules for the clinical treatment of CMF bone defects. Further, it provides a perspective on the efficacy of biomolecule delivery in CMF bone regeneration by reviewing presently available reports of pre-clinical studies using various animal models.
Advanced drug delivery reviews 03/2012; 64(12):1152-64. · 11.96 Impact Factor
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ABSTRACT: Microcystins (MCs) can cause evident hepatic apoptosis. In vitro studies indicated that uptake of MC by isolated hepatocytes was dramatically reduced as ambient temperature dropped, and some studies presented a hypothesis that differences in core body temperatures in animals result in diverse uptake of MC, as well as different toxic effects. Thus far, however, few in vivo studies have been conducted to investigate the effects of temperature on MC-induced hepatocyte apoptosis in fish, a typical poikilotherm. In the present study, zebrafish were treated with MC-LR, an MC metabolite, at three water temperatures (12, 22 and 32 °C), and evident differences in apoptotic profiles were observed. Damage to liver ultrastructures revealed temperature-dependent early-stage patterns of apoptosis. Flow-cytometric analysis indicated that hepatocyte apoptotic rates varied with a temperature-dependent effect. The transcription levels of some apoptosis-related genes were determined using quantitative real-time polymerase chain reaction, and significantly elevated gene expressions of P53, Bcl-2, Bax and caspase-3 were found in the 12 and 32 °C groups. Results of the present study indicate that different ambient temperatures can lead to various toxic effects of MCs on hepatic apoptosis in fish. Copyright © 2012 John Wiley & Sons, Ltd.
Journal of Applied Toxicology 03/2012; · 2.48 Impact Factor
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ABSTRACT: A new concept in which only the molecular target, such as a thiol-bearing protein, can activate the phototrigger has been demonstrated. Such target-activatable phototriggers comprise three parts: a 7-aminocoumarin phototrigger, an electron acceptor (maleimide) that efficiently quenches the coumarin excited state, and a caged leaving group attached to the coumarin. In the absence of mercaptans, photoinduced electron transfer between coumarin and maleimide effectively blocks both the fluorescence and photocleavage pathways. Thiol-bearing molecules, however, readily annihilate the electron acceptor and thus restore the phototrigger for photorelease of the caged cargo (e.g., biotin). Unlike traditional phototriggers, functional-group-activated phototriggers allow easy handling under ambient light, report specific bonding to the target, and enable photocleavage capability selectively at the binding site in situ, thus effectively positioning the photoreleased cargo at the target. Meanwhile, the unique feature of thiol-specific activation of the fluorescence and photocleavage make our new phototrigger a universal tool that can be used to identify accurately protein cysteine S-nitrosylation, a physiologically important posttranslational modification.
Journal of the American Chemical Society 03/2012; 134(11):5052-5. · 9.91 Impact Factor
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ABSTRACT: Highly sensitive, multicomponent broadband photodetector devices are made from PbSe/graphene/TiO(2). TiO(2) and PbSe nanoparticles act as light harvesting photoactive materials from the UV to IR regions of the electromagnetic spectrum, while the graphene acts as a charge collector for both photogenerated holes and electrons under an applied electric field.
Advanced Materials 02/2012; 24(13):1697-702. · 13.88 Impact Factor
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ABSTRACT: Reversibly switchable fluorescent proteins (RSFPs) have attracted widespread interest for emerging techniques including repeated tracking of protein behavior and superresolution microscopy. Among the limited number of RSFPs available, only Dronpa is widely employed for most cell biology applications due to its monomeric and other favorable photochemical properties. Here we developed a series of monomeric green RSFPs with beneficial optical characteristics such as high photon output per switch, high photostability, a broad range of switching rate, and pH-dependence, which make them potentially useful for various applications. One member of this series, mGeos-M, exhibits the highest photon budget and localization precision potential among all green RSFPs. We propose mGeos-M as a candidate to replace Dronpa for applications such as dynamic tracking, dual-color superresolution imaging, and optical lock-in detection.
Proceedings of the National Academy of Sciences 02/2012; 109(12):4455-60. · 9.68 Impact Factor
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Wenjing Sun,
Changlong Guo,
Xiangning Meng,
Yang Yu,
Yan Jin,
Dandan Tong,
Jingshu Geng,
Qi Huang,
Jiping Qi,
An Liu,
Rongwei Guan,
Lidan Xu,
Donglin Sun, Wei Ji,
Peng Liu,
Fangli Liu,
Haiming Sun,
Guohua Ji,
Songbin Fu,
Jing Bai
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ABSTRACT: Human non-small cell lung cancer (NSCLC) is one of the most common malignancies in the modern world. Its recurrence is mainly due to its ability to invade and metastasize. However, the precise mechanism for tumor development and metastasis is still not fully understood. To shed light on the development of lung cancer, the human giant cell lung carcinoma cell lines 95D with high metastatic potential and 95C with low metastatic potential were selected in this study. The 2 cell lines originated from the same parental cell and share a similar genetic background. In the current study, we identified 3 differentially expressed proteins in 95C and 95D cell lines, namely, PAI-RBP1, C1orf142, and COTL1, by using 2-dimensional electrophoresis proteomics analysis. We found that PAI-RBP1 and C1orf142 expression levels were higher in 95D than in 95C cells, whereas COTL1 expression level was lower in 95D when compared to 95C cells. We also confirmed these results by reverse transcription-polymerase chain reaction and immunoblotting analyses. The messenger RNA and protein levels of PAI-RBP1 and C1orf142 were much higher in 95D than in 95C cells, and COTL1 expression level was lower in 95D than in 95C cells. The PAI-RBP1 expression was assessed by immunohistochemistry in 70 NSCLC and 7 normal lung tissue samples from patients. PAI-RBP1 expression level was higher in tumor tissues (positive staining in 87.1% of cases [61/70]) than in normal tissues (positive staining in 14.3% of cases [1/7]). In conclusion, by studying protein expression in NSCLC cell lines with high and low metastasis as well as in human lung cancer tissues, we have identified 3 proteins, namely, PAI-RBP1, C1orf142, and COTL1, which were differentially expressed in NSCLC cell lines with different metastatic potential. In addition, we also found that PAI-RBP1 might contribute to NSCLC development.
Journal of Investigative Medicine 02/2012; 60(4):689-94. · 1.96 Impact Factor
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ABSTRACT: Since the processes of normal embryogenesis and neoplasia share many of similar pathways, tumor development has been interpreted as an abnormal form of organogenesis. NANOG is a homeodomain-containing transcription factor that functions to maintain self-renewal and proliferation of embryonic stem cells (ESCs). Aberrant expression of NANOG has been observed in many types of human malignancies. However, its potential implication in tumorigenesis has not been fully clarified. In this study, we have employed small interference RNA (RNAi) technology to silence endogenous NANOG expression in breast cancer cells and successfully selected three independent clones with stably inhibited NANOG expression of MCF-7 cells. Functional analysis revealed that down-regulation of NANOG reduced cell proliferation, colony formation and migration ability of MCF-7 cells. Consistently, proliferation of breast cancer MDA-MB-231 cells was also significantly inhibited after the knockdown of NANOG expression. Interestingly, we found that the expression levels of cyclinD1 and c-myc were markedly down-regulated and the cell cycle were blocked at the G0/G1 phases after the knockdown of NANOG, while the expression of cyclinE and signal transducers and activators of transcription3 (STAT3) remained unaffected. In addition, the expression of NANOG and cyclinD1 can be rescued after the transfection of pcDNA3.1 (-)-NANOG expression vector into the three clones. Finally, our chromatin immunoprecipitation (ChIP) experiment showed that NANOG protein can bind to the promoter region of cyclinD1 and regulate cells cycle. Taken together, our findings may not only establish a molecular basis for the role of NANOG in modulating cell cycle progression of breast cancer cells but also suggest a potential target for the treatment of at least some subtypes of breast cancer.
Cancer letters 02/2012; 321(1):80-8. · 4.86 Impact Factor
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ABSTRACT: To study the anatomic parameters related to clival screw and establish reference data concerning the craniovertebral fixation technique.
Morphometric measurement of the clivus and the surrounding anatomic structures were obtained on 41 dry bone specimens. Then, 2-D CT reconstruction of the craniovertebral region of 30 patients (19 men and 11 women, ranging in age from 20-64 years with an average age of 38.8 years) were performed to measure the safety range for a 3.5-mm screw placement. Nine entry points were evaluated. Finally, one male fresh cadaver specimen (age 46 years) was dissected to observe the craniovertebral region.
The clivus faces the basilar artery, the V ~ XII cranial nerves, the pons, and ventral medulla oblongata at its intracranial surface. The longitudinal diameter of extracranial clivus was 25.87 ± 2.64 mm. The narrowest diameter of the clivus was 12.84 ± 1.08 mm, the distance between the left and right hypoglossal canal was 32.70 ± 2.09 mm at its widest part. The distance between the left and right structures, the maximum value was 49.31 ± 4.16 mm at carotid canal, the minimum value was 16.54 ± 2.04 mm at the occipital condyle. The measurement of clival screws placement simulation via 2-D CT reconstruction images shows the maximum upper insertion angle of three components the optimal entry points, the candidate points, the limit entry points was 130.19°, 125.23° and 85.72°, and the total mean screw length was 7.57, 10.13 and 15.6 mm at the vertical entry angle, respectively.
Clival screw placement is a viable option for craniovertebral fixation. There is a safe scope for the screw length and angle of the screw placement. And, these parameters obtained in the present study will be helpful for anyone contemplating the use of clival screw fixation.
European Spine Journal 02/2012; 21(8):1483-91. · 1.97 Impact Factor
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Applied Physics Letters 02/2012; 100(9):093116. · 3.84 Impact Factor
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ABSTRACT: Using homologous cloning and RT-PCR technology, we isolated a novel TIFY family gene, GsTIFY11b, from Glycine soja L. G07256, a species that is tolerant to saline and alkaline environments. Phylogenetic analysis indicated that GsTIFY11b was closely related to AtTIFY11a with 56% similarity in amino acid identity. Protein sequence analysis showed that GsTIFY11b protein also had conserved TIFY domain, N-terminal domain, and a C-terminal Jas motif. Quantitative realtime PCR analysis indicated that the expression of GsTIFY11b was induced by both saline and alkaline stresses. Two homozygous GsTIFY11b over-expressing transgenic Arabidopsis lines were obtained. Phenotypic analysis of the transgenic and wild-type Arabidopsis indicated that over-expressing GsTIFY11b in Arabidopsis did not enhance plant tolerance to saline and alkaline stresses, whereas it showed an increased sensitivity to saline stress during seed germination and seedling development. Expression analysis of saline stress response marker genes in transgenic and wild-type plants under stress condition indicated that GsTIFY11b regulated the expression of RD29B, KIN1, and DREB. The transient expression of a GsTIFY11b-GFP fusion protein in onion epidermal cells showed that GsTIFY11b was localized to the nucleus, suggesting a role as a transcriptional regulator in the saline stress response pathway.
Hereditas (Beijing) 02/2012; 34(2):230-9.
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ABSTRACT: Exceptional optical limiting properties were observed in coupled Au and Ag nanoparticles that are induced by conjugated polymers. Fluence-dependent transmission measurements using 7-ns laser pulses of 532-nm wavelength showed that the optical limiting properties of Au and Ag nanoparticles were significantly enhanced upon assembly induced by addition of cationic conjugated polymers. The optical limiting performances of coupled Au and Ag nanoparticles (with optical limiting threshold as low as 2.8 J/cm2 and 2.6 J/cm2, respectively) are even better than that of the benchmark optical limiter-carbon nanotube suspensions (with threshold of 3.6 J/cm2). In addition, these coupled Au and Ag nanoparticle solutions are very stable and suitable for practical applications. Input fluence and angle-dependent scattering experiments suggested that nonlinear scattering should play an important role in the observed optical limiting effects.
Applied Physics Letters 01/2012; · 3.84 Impact Factor
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Meeting Abstracts. 01/2012; MA2012-01(29):1117.
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Bo-jun Wei,
Hong Shen,
Xiao-ping Xing, Wei Ji,
Liang Zhao,
Jia Wang,
Hong Xie,
Xiao-hong Zhou,
Jin-shu Yin,
Tao Jiang,
Hong Chang,
Feng Shi
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ABSTRACT: To evaluate the factors contributed to the recurrence of parathyroid carcinoma with the invasion of the upper aerodigestive tract and the outcomes of reoperation.
Six cases reviewed, in which the age ranged from 32 to 79 years old. The initial diagnoses and surgical procedures, the sites and surgical treatment of the recurrent disease, and the chemical markers, such as parathyroid hormone (PTH) and serum calcium, were retrospectively studied. The preoperative PTH levels ranged from 860 to 2830 ng/L. In 4 patients the recurrence diseases were founded in the tracheoesophageal groove, of them one with invasion of the larynx only and one with invasion of the larynx and pharynx in addition to the trachea and esophagus involvement. Selective neck dissection for level II, III, IV and VI was taken in all cases in addition to the removal of the local recurrent diseases. Recurrent laryngeal nerves were so badly embedded in tumor tissue that they were intentionally resected in 4 patients although they were functionally normal before operation. Prophylactic tracheostomy was carried out in 5 cases.
PTH level dropped more than 70% of that prior the operation at 10 min after the removal of the tumor-bearing tissues and to normal range within the first 2 hours postoperatively, and hypocalcemia disappeared in 2 days postoperatively. All cases experienced significant improvement in symptoms and signs in the first three days postoperatively. PTH and serum calcium levels were within normal range in 4 cases during the follow-up of 11 to 40 months, while hyperparathyroidism was encountered 8 and 11 months postoperatively in other 2 cases, respectively. Esophageal fistula, chylous fistula and dehiscence of sternotomy developed in 3 cases separately. Of 5 patients with tracheostomy, the tracheostomy tubes were removed two weeks in 4 cases and six weeks in the other one after operation.
Recurrent parathyroid carcinoma even with invasion of the upper aerodigestive tract still has promising surgical outcomes. Both the precise localization of the recurrent diseases and the intraoperative PTH assay are importance to the successful treatment of these diseases.
Zhonghua er bi yan hou tou jing wai ke za zhi = Chinese journal of otorhinolaryngology head and neck surgery 11/2011; 46(11):901-4.
