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Biomedical subjects

Gang Cheng

Publications and source records attributed to Gang Cheng.

At least 55 records · Page 3Linked to original sources

MUC5AC expression up-regulation goblet cell hyperplasia in the airway of patients with chronic obstructive pulmonary disease.

OBJECTIVE: To determine the number of goblet cells, the change of MUC5AC expression in chronic obstructive pulmonary disease (COPD) patients and the relationship of smoking with goblet cell, MUC5AC, and lung function. METHODS: Eighteen patients undergoing lung resections for a solitary peripheral carcinoma were classified by lung function as having COPD. Twenty patients with normal lung function served as the control group. Normal lobe bronchioles far away from the lesion site were taken for paraffin section. Goblet cells were identified by AB/PAS staining and the expression of MUC5AC in the paraffin's section was tested by immunohistochemistry. RESULTS: Goblet cell hyperplasia was observed in the COPD group. The positive rate of goblet cell in COPD group (0.20% +/- 0.10%) was significantly higher than that in the normal lung function group (0.13% +/- 0.06%, P < 0.05). The positive rate of MUC5AC expression in the COPD group (0.27% +/- 0.09%) was higher than that in the normal lung function group (0.20% +/- 0.10%, P < 0.05). The positive rate of goblet cell in smokers (27.93% +/- 9.00%) of the COPD group and normal lung function group was higher than that in non-smokers (17.70% +/- 9.37%, P < 0.05), while MUC5AC expression had no significant difference between smokers and non-smokers (17.88% +/- 6.44% and 10.88% +/- 7.10%, respectively). CONCLUSION: For COPD patients with declined lung function, there were goblet cell hyperplasia and increased expression of MUC5AC. MUC5AC expression up-regulation may due to goblet cell hyperplasia. Smoking may be an important factor for goblet cell hyperplasia.

Aged↗

[Study on mRNA expression of fibronectin and integrin beta1 during fracture healing].

OBJECTIVE: To investigate the spatial and temporal expression changes of fibronectin and integrin beta1 mRNA during fracture healing. METHODS: Using in situ RT-PCR technique, the spatial and temporal expression pattern of both fibronectin and integrin beta1 mRNA was detected on paraffined slices in different rabbit mandibular fracture healing phases. RESULTS: (1) The mRNA of integrin beta1 and fibronectin was widely expressed in fractured bone cells. The positive stain existed in cytoplasm and nucleolus. (2) After 7 days of fracture, increaseded integrin beta1 mRNA expression was observed, and it reached maximal levels approximately 14- 30 days post-fracture and returned to normal levels after 60 - 90 days. (3) Fibronectin mRNA was detected on 3 days post-fracture, it reached maximal levels at 7 - 14 days, faint expression was detected at 30 days, undetectable 60 days afterwards. CONCLUSION: During fracture healing, the mRNA expression of integrin beta1 and fibronectin increased locally, FN and Itg beta1 cooperate with each other, it is suggested that they have an important influence on fracture healing.

Animals↗

[Effect of warming needle moxibustion on pain threshold in the patient of sciatica].

OBJECTIVE: To observe effect of warming needle moxibustion on pain threshold in the patient of sciatica. METHODS: Ninety cases were randomly divided into 3 groups, 30 cases in each group. The warming needle moxibustion group were treated with warming needle moxibustion at Shenshu (BL 23), Dachangshu (BL 25), Huantiao (GB 30), etc; the western medicine group with oral administration of Nimeisulide; and the acupoint-injection group with injection of 654-2 into the same acupoints as those in the warming needle moxibustion group. RESULTS: The cured rates were 56.67%, 26.67% and 20.00% in the 3 groups, and the total effective rate were 90.00%, 73.33% and 63.33%, respectively, the therapeutic effect of the warming needle moxibustion group being better than those of other two groups (both P < 0.01). The amplitude of pain threshold increase in the warming needle moxibustion group was higher than those of other two groups (both P < 0.01). CONCLUSION: Warming needle moxibustion can increase pain threshold, improve symptoms and raise quality of life for the patient of sciatica.

Humans↗

Central vagal sensory and motor connections: human embryonic and fetal development.

The embryonic and fetal development of the nuclear components and pathways of vagal sensorimotor circuits in the human has been studied using Nissl staining and carbocyanine dye tracing techniques. Eight fetal brains ranging from 8 to 28 weeks of development had DiI (1,1'-dioctadecyl-3,3,3',3' tetramethylindocarbocyanine perchlorate) inserted into either the thoracic vagus nerve at the level of the sternal angle (two specimens of 8 and 9 weeks of gestation) or into vagal rootlets at the surface of the medulla (at all other ages), while a further five were used for study of cytoarchitectural development. The first central labeling resulting from peripheral application of DiI to the thoracic vagus nerve was seen at 8 weeks. By 9 weeks, labeled bipolar cells at the ventricular surface around the sulcus limitans (sl) were seen after DiI application to the thoracic vagus nerve. Subnuclear organization as revealed by both Nissl staining and carbocyanine dye tracing was found to be advanced at a relatively early fetal age, with afferent segregation in the medial Sol apparent at 13 weeks and subnuclear organization of efferent magnocellular divisions of dorsal motor nucleus of vagus nerve noticeable at the same stage. The results of the present study also confirm that vagal afferents are distributed to the dorsomedial subnuclei of the human nucleus of the solitary tract, with particular concentrations of afferent axons in the gelatinosus subnucleus. These vagal afferents appeared to have a restricted zone of termination from quite early in development (13 weeks) suggesting that there is no initial exuberance in the termination field of vagal afferents in the developing human nucleus of the solitary tract. On the other hand, the first suggestion of afferents invading 10N from the medial Sol was not seen until 20 weeks and was not well developed until 24 weeks, suggesting that direct monosynaptic connections between the sensory and effector components of the vagal sensorimotor complex do not develop until this age.

Carbocyanines↗

[Quantitative analysis of Epstein-Barr virus DNA in plasma and peripheral blood cells in patients with nasopharyngeal carcinoma].

OBJECTIVE: To quantitative analysis of Epstein-Barr virus (EBV) DNA levels in plasma, peripheral blood cells (PBCs) and tumor tissue in nasopharyngeal carcinoma (NPC), to investigate the relationship between EBV-DNA levels and clinical parameters. METHODS: Blood of 150 primary NPC and 49 corresponding tumor tissues, 47 nasopharyngitis tissues and blood of 75 controls were entered this investigation. Plasma and PBCs were isolated for quantitative detection of EBV-DNA by using real-time quantitative PCR (RQ-PCR). The paraffin-embedded tissue sections were conducted to quantitative detection of EBV-DNA, and EBER1 in situ hybridization (ISH) for calculating the percentage of positive cells on the tissue section. RESULTS: Plasma EBV-DNA levels and detecting rate in NPC before treatment (median 82 500 copies/ml, 92%) were significantly higher than that in NPC after treatment (median 0 copy/ml, 19%) and in controls (median 0 copy/ml, 12%) (P < 0.05), whereas there was no significant difference between NPC after treatment and controls (P > 0.05). There was no significant difference of PBCs EBV-DNA load and detecting rate in NPC before (0 copy/actin, 24%) and after treatment (0 copy/actin, 14%), as well as in controls (0 copy/actin, 16%) (P > 0.05). Plasma EBV-DNA level was not correlated to PBCs EBV-DNA load in NPC before (P = 0.92) and after treatment (P = 0.27), and controls (P = 0.74). EBV-DNA level (27.8 copies/actin) in NPC tumor tissues was significantly higher than that in nasopharyngitis (0 copy/actin) (P < 0.05), and was positively correlated to the ratio of EBER1 positive cells to total cells on the NPC section. In NPC patients, plasma EBV-DNA level was significantly increased in TNM stage I (2500 copies/ml), II (32 590 copies/ml), III (86 000 copies/ml) and IV (166 200 copies/ml), whereas there was no significantly difference of PBCs EBV-DNA loads in difference stages of NPC. CONCLUSION: Plasma EBV-DNA level is a more sensitive and reliable biomarker than PBCs EBV-DNA loads for reflection the tumor volumes in NPC patients. Plasma EBV-DNA detection will improve TNM staging in NPC clinical practice on molecular level.

Biomarkers, Tumor↗

Time- and pH-dependent colon-specific drug delivery for orally administered diclofenac sodium and 5-aminosalicylic acid.

AIM: To investigate Time- and pH-dependent colon-specific drug delivery systems (CDDS) for orally administered diclofenac sodium (DS) and 5-aminosalicylic acid (5-ASA), respectively. METHODS: DS tablets and 5-ASA pellets were coated by ethylcellulose (EC) and methacrylic acid copolymers (Eudragit L100 and S100), respectively. The in vitro release behavior of the DS coated tablets and 5-ASA coated pellets were examined, and then in vivo absorption kinetics of DS coated tablets in dogs were further studied. RESULTS: Release profile of time-dependent DS coated tablets was not influenced by pH of the dissolution medium, but the lag time of DS release was primarily controlled by the thickness of the coating layer. The thicker the coating layer, the longer the lag time of DS release is. On the contrary, in view of the pH-dependent 5-ASA coated pellets, 5-ASA release was significantly governed by pH. Moreover, the 5-ASA release features from the coated pellets depended upon both the combination ratio of the Eudragit L100 and S100 pH-sensitive copolymers in the coating formulation and the thickness of the coating layer. The absorption kinetic studies of the DS coated tablets in dogs demonstrated that in vivo lag time of absorption was in a good agreement with in vitro lag time of release. CONCLUSION: Two types of CDDS, prepared herein by means of the regular coating technique, are able to achieve site-specific drug delivery targeting at colon following oral administration, and provide a promising strategy to control drug release targeting the desired lower gastrointestinal region.

Administration, Oral↗

Comparison of plasma Epstein-Barr virus (EBV) DNA levels and serum EBV immunoglobulin A/virus capsid antigen antibody titers in patients with nasopharyngeal carcinoma.

BACKGROUND: Serologic measurement of antibodies to Epstein-Barr virus (EBV) immunoglobulin A/viral capsid antigen (IgA/VCA) and early antigen (IgA/EA) has been used widely to screen for nasopharyngeal carcinoma (NPC) in China. Recently, it was found that plasma EBV DNA concentration is an indicator for the staging and prognosis of patients with NPC. To determine whether there is a correlation between plasma EBV DNA levels and serum levels of IgA/VCA, the authors measured both in patients with NPC and in a control group. METHODS: Real-time polymerase chain reaction was used for quantitative analysis of plasma EBV DNA concentration, and enzyme-linked immunoadsorbent assay was used to measure EBV VCA/IgA in patients with primary NPC (n = 120 patients), locally recurrent NPC (n = 8 patients), and distant metastatic NPC (n = 21 patients) among 76 patients with NPC after the completion of radiotherapy, in 60 patients with NPC in clinical remission, in 38 patients with non-NPC tumors, and in 47 control individuals. RESULTS: The median plasma EBV DNA levels were 6200 copies/mL, 9200 copies/mL, and 2050 copies/mL in patients with primary, locally recurrent, and distant metastatic NPC, respectively, but declined to 0 copies/mL in patients with clinically remissive NPC, in patients who completed radiotherapy, in patients with non-NPC tumors, and in the control group. In contrast, EBV VCA/IgA titers and detection rates remained high in all NPC groups. Plasma EBV DNA levels were significantly higher in patients who had serum VCA/IgA titers > or = 1:640 (median, 83,450 copies/mL) compared with the levels in patients who had titers < or = 1:320 (median, 17,200 copies/mL). Patients with NPC who had advanced TNM stage (Stages III and IV; median, 8530 copies/mL) and T classification (T3 and T4 tumors; median, 8530 copies/mL) had significantly higher plasma EBV DNA levels compared with patients who had early TNM stage (Stages I and II; median, 930 copies/mL) and T classification (T1 and T2 tumors; median, 3700 copies). Patients who had advanced TNM stage NPC had significantly higher mean VCA/IgA titers (1:424) compared with patients who had early TNM stage NPC (1:246), but there was no correlation between IgA/VCA titer and T or N classification of NPC. CONCLUSIONS: The results suggest that plasma EBV DNA detection is a more sensitive and specific marker than the serum IgA/VCA titer for the diagnosis and monitoring of patients with NPC. These findings provide convincing evidence for the use of plasma EBV DNA measurements for the early diagnosis and staging of NPC as well as for monitoring recurrence and metastasis of this tumor.

Antibodies, Viral↗

Steatotic liver transplantation in the mouse: a model of primary nonfunction.

BACKGROUND: The number of potential donor organs deemed suboptimal for transplantation because of hepatic steatosis is rising as the obesity rate increases. However, no mouse transplant model has been described within the framework of hepatic steatosis. We describe the development of and our initial experience with a steatotic mouse orthotopic liver transplant model using the ob/ob mouse. This model is technically achievable and functionally mimics primary nonfunction. MATERIALS AND METHODS: Adapting techniques of a nonarterialized murine transplant model, C57BL6 ob/ob mice aged 5-7 weeks (26-35 g) and lean controls served as liver donors and recipients. Orthotopic liver transplantation (OLT) was performed using a two-cuff technique at the infrahepatic cava and portal vein. The suprahepatic cava was anastomosed end to end, and the bile duct was stented. The hepatic artery was not reconstructed. RESULTS: Lean-to-lean OLT was performed with 70% (n = 10) long-term survival. ob/ob-to-age-matched lean recipients had 0% (n = 10) survival because of size discrepancy. ob/ob livers were transplanted to size-matched lean recipients (>3 months old) with short-term survival of 30% (n = 10). These mice survived the operation, awakened, but expired within 24 h. Serum transaminases revealed a significantly higher injury profile in the recipients of the steatotic livers, and histology showed massive centrilobular coagulative necrosis with hemorrhage, the overall picture being that of primary nonfunction. CONCLUSIONS: This novel use of the ob/ob mouse for OLT provides us with a model for steatotic transplantation with primary nonfunction as the end point and may help to better understand the response of the steatotic liver to the insult of transplantation.

Animals↗

Development of an unbiased method for the estimation of liver steatosis.

BACKGROUND: Steatosis significantly contributes to an organ's transplantability. Livers with >30% fat content have a 25% chance of developing primary non-function (PNF). The current practice of evaluating a hematoxylin and eosin (H&E) stained donor biopsy by visual interpretation is subjective. We hypothesized that H&E staining of frozen sections fails to accurately estimate the degree of steatosis present within a given liver biopsy. To address this problem of evaluating steatosis in prospective donor organs, we developed a fast, user friendly computer methodology to objectively assess fat content based on the differential quantification of color pixels in Oil Red O (ORO) stained liver biopsies. METHODS: The accuracy of human visual estimation of fat content by H&E and ORO stains was compared with computer-based measurements of the same slides from 25 frozen sections of donor biopsies. RESULTS: Samples with a fat content >20% showed marked variation between human interpretation and computer analysis. There was also a significant difference in the human interpretation of fat based on the method of staining. This difference ranged from 3 to 37% with H&E. DISCUSSION: Use of ORO resulted in a more consistent estimation of liver steatosis compared with H&E, but human interpretations failed to correlate with computer measurements. Such differences in fat content estimations might result in the rejection of a potentially transplantable organ or the acceptance of a marginal one. Ideally, our protocol can rapidly be applied to clinical practice for accurate and consistent measurement of fat in liver sections for the ultimate purpose of increasing the number of successful transplantable organs.

Algorithms↗

Fatty acid synthase blockade protects steatotic livers from warm ischemia reperfusion injury and transplantation.

Cerulenin has been shown to reduce body weight and hepatic steatosis in murine models of obesity by inhibiting fatty acid synthase (FAS). We have shown that attenuating intrahepatocyte lipid content diminished the sensitivity of ob/ob mice to ischemia/reperfusion injury and improved survival after liver transplantation. The mechanism of action is by inhibition of fatty acid metabolism by downregulating PPARalpha, as well as mitochondrial uncoupling protein 2 (UCP2), with a concomitant increase in ATP. A short treatment course of cerulenin prior to I/R injury is ideal for protection of steatotic livers. Cerulenin opens the potential for expanding the use of steatotic livers in transplantation.

Adenosine Triphosphate↗

Anti-endotoxin monoclonal antibodies are protective against hepatic ischemia/reperfusion injury in steatotic mice.

Steatotic mice are particularly susceptible to hepatic ischemia/reperfusion injury compared with their lean littermates. We have previously demonstrated that livers of mice having a spontaneous mutation in the leptin gene (ob/ob), resulting in global obesity and liver steatosis, are ATP depleted, are endotoxin sensitive, and do not survive (I/R) injury. We hypothesize that administration of an anti-LPS monoclonal antibody (mAb) prior to initiation of I/R would be protective from that insult. Steatotic mice (ob/ob) were subjected to 15 min of ischemia via complete porta-hepatis occlusion and varying lengths of reperfusion with or without pre-treatment with an anti-LPS mAb. There was 14-31% survival of isotype matched control mAb treated ob/ob mice after 15 min of ischemia and 24 h of reperfusion. In contrast, 75-83% of ob/ob mice pre-treated with an anti-LPS mAb prior to initiation of I/R survived both ischemia and 24 h of reperfusion. Furthermore, there was a decrease in ALT and circulating endotoxin levels when treated with an anti-LPS mAb compared with control antibodies. Attenuation of the endotoxin load with anti-LPS mAb, prior to initiation of I/R, was cytoprotective and improved survival. Consequently, these studies might offer a solution to the problems associated with using steatotic livers in clinical transplantation.

Animals↗

Multidrug resistance P-glycoprotein: crucial significance in drug disposition and interaction.

This article reviews recent advances in our understanding of the structure, drug interaction mechanism, and substrate molecular requirements of P-glycoprotein (P-gp) and its emerging crucial role in drug disposition and the modulation of drug interaction. In view of its wide localization in normal tissues, the broad variety of structurally and functionally unrelated substrates of P-gp, and its ATP-dependent outward-oriented transport, P-gp actively participates in intestinal secretion, blood-tissue barriers, and biliary and renal excretions for many exogenous substrates, and also performs a protective role to prevent entry of xenobiotics. Moreover, the importance of P-gp-mediated drug interactions in clinical practice can hardly be underestimated, since it may result in severe side effects, such as digitalis drug interaction. Polymorphism or single nucleotide polymorphism (SNP) associated with P-gp may exert a significant effect on the pharmacokinetic behavior of its substrates, a fact which has major clinical implications and suggests careful dose adjustment for individual treatment. Moreover, dietary components and pharmaceutical excipients may modulate P-gp activity, and as a result affect in vivo drug disposition and therapeutic efficacy; examples include grapefruit juice, Pluronic P85, PEG 300, etc. In summary, it should be emphasized that P-gp is an integral component in the process of drug discovery, development strategy,

ATP Binding Cassette Transporter, Subfamily B, Mem↗

[Six novel mutations in PAH gene detected by sequencing].

OBJECTIVE: To explore new mutation in phenylalanine hydroxylase (PAH) gene. METHODS: The PAH genes from 40 phenylketonuria (PKU) patients and 30 normal controls were screened by PCR-single strand conformation polymorphism (SSCP) and further sequencing. RESULTS: Eleven mutations and 3 polymorphisms in PAH gene were found. No abnormalities in the PAH gene from 30 controls were detected. CONCLUSION: M276K, M276R, 280insT, IVS10nt+32T-->A, IVS4nt+47C-->T were demonstrated as novel mutations in comparison with the PAH mutation database. One mission mutation (H290R) was first documented in Chinese PKU gene.

DNA Mutational Analysis↗

[Report of gene mutation hot spots analysis in one congenital cataract pedigree].

PURPOSE: To analyse autosomal dominant gene mutation hot spots in a four-generation Chinese congenital cataract pedigree. METHODS: Nineteen family members of the pedigree (including eight affected and eleven unaffected individuals) were enrolled into the study with informed consent. The eight affected individuals underwent a full ophthalmologic and general examination to rude out any concomitant disorders. The eleven unaffected individuals only underwent ophthalmologic examination. Blood samples were taken from the nineteen subjects for genomic DNA preparation. Seventeen distinct loci on ten different genes (including CRYAA, CRYAB, CRYBA1/A3, CRYGD, GJA8, CRYGC, CRYBB2, GJA3, MIP and BFSP2) have been identified as causes of autosomal dominant congenital cataract (ADCC). Polymerase chain reaction (PCR) amplification of ten gene segments encompassing seventeen mutation hot spots were carried out in the nineteen subjects of the pedigree. Sequences and analysis of PCR products were then performed to detect corresponding mutations. RESULT: No mutation was found on the seventeen autosomal dominant mutation hot spots in all nineteen subjects. CONCLUSION: Preliminarily exclude the association of the seventeen published autosomal dominant mutation hot spots with ADCC in this family.

Cataract↗

Organ distribution of 5-fluorouracil loaded gelatine microspheres in mice.

The aim of this study was to investigate the organ distribution characteristics of 5-fluorouracil (5-Fu) loaded crosslinked gelatine microspheres (5-Fu-MS) after intravenous (i.v.) injection compared to 5-Fu solution in mice, and to evaluate the targetability of 5-Fu-MS. The concentrations of 5-Fu in mice plasma, heart, liver, lung, kidney, spleen and brain were determined by HPLC. The parameters drug targeting index C(e), time-averaged relative drug exposure values r(e), drug targeting efficiency t(e), and drug distributed to target-tissue (%) were used to evaluate the targetability of the 5-Fu-MS delivery system. The results showed that the concentration of 5-Fu in the lung was significantly higher than after application of 5-Fu solution, and that the maximum concentration of 5-Fu, 72.8 microg x g organ(-1), was reached in the lung at 15 min after i.v. administration. As for 5-Fu-MS, r(e) was calculated to be 2.2, and t(e) was considerably higher than after application of 5-Fu in solution. Furthermore, the percentage of drug distributed to the lung was 2 times as high as after application in solution. Accordingly, 5-Fu-MS were capable of effectively delivering 5-Fu to the lung and possessed specific targetability towards the lung compared to 5-Fu solution.

Algorithms↗

An engineered multidomain bactericidal peptide as a model for targeted antibiotics against specific bacteria.

We constructed a peptide consisting of a staphylococcal AgrD1 pheromone fused to the channel-forming domain of colicin Ia and named it pheromonicin. This fusion peptide had bactericidal effects against methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA and MRSA, respectively), but not against Staphylococcus epidermidis or Streptococcus pneumoniae. Growth rates, vital staining and colony forming unit (CFU) counts showed that pheromonicin did not merely suppress growth but killed S. aureus cells. The specificity of pheromonicin was shown by the absence of bactericidal effects against an accessory gene regulator (agr) locus knockout of S. aureus, and a dose-dependent inhibition of the bactericidal effects of pheromonicin by competition with corresponding free AgrD pheromone. In vivo, all pheromonicin-treated mice survived administration of MRSA that was lethal to controls. No toxicity was detectable in human liver or renal cells in culture, or in livers, kidneys or spleens of pheromonicin-treated mice. The results suggest that these types of chimeric peptides may be of value as antibiotics against specific bacterial infections.

Amino Acid Sequence↗

Cyto- and chemoarchitecture of the hypothalamus of a wallaby ( Macropus eugenii) with special emphasis on oxytocin and vasopressinergic neurons.

We have studied the organization of the hypothalamus in an Australian diprotodontid metatherian mammal, the wallaby ( Macropus eugenii), using cytoarchitectural, histochemical and immunohistochemical techniques. Coronal sections of adult brains were processed for Nissl staining, histochemical reactivity (cytochrome oxidase, nicotinamide adenine dinucleotide phosphate diaphorase and acetylcholinesterase) and immunohistochemistry (antibodies to tyrosine hydroxylase, calbindin, calretinin, non-phosphorylated neurofilament protein, oxytocin and vasopressin). The distribution of immunoreactive neurons for these substances was mapped with the aid of a computer-linked microscope. In general, the wallaby hypothalamus showed a similar nuclear organization to that seen in rodents. The paraventricular nucleus could be divided into several subdivisions based on the different cellular parcellation, similar to that described in rodents. The ventromedial hypothalamic nucleus had cell-sparse dorsomedial and cell-dense ventrolateral subdivisions as seen in eutheria, suggesting a similar functional compartmentalization in all theria. The positions of tyrosine hydroxylase-positive neurons in the wallaby hypothalamus were also similar to those in eutheria. Oxytocin and vasopressinergic neurons were found in all the same major nuclear groups as seen in eutheria, although a nucleus circularis could not be identified. The general similarities between wallaby and eutherian hypothalamus indicate that the basic chemo- and cytoarchitectural features of the hypothalamus are common to eutheria and metatheria and validate the use of the wallaby as a mammalian model of wide applicability in investigations of hypothalamic functional development.

Acetylcholinesterase↗

Synthesis, characteristics and luminescence properties of oligo(phenylenevinylene) dimers with a biphenyl linkage center.

Building a new structual oligo(phenylenevinylene) by linking trimeric phenylenvinylene (TPV) through the phenylphenyl bond of a central phenylene ring was reported. The resultant TPV dimers exhibit weak intermolecular interactions and intense blue photoluminescence in the solid state as well as high phase transition temperatures up to 250 degrees C. Organic light-emitting devices (OLEDs) based on these materials display blue emission with low turn-on voltage (about 3 V), maximum luminance approaching 2000 cd m(-2) and efficiency up to 1.6 cd A(-1).

Journal Article↗