RESUMO
Generating circularly polarized luminescence (CPL) with simultaneous high photoluminescence quantum yield (PLQY) and dissymmetry factor (glum) is difficult due to usually unmatched electric transition dipole moment (µ) and magnetic transition dipole moment (m) of materials. Herein we tackle this issue by playing a "cascade cationic insertion" trick to achieve strong CPL (with PLQY of ~100 %) in lead-free metal halides with high glum values reaching -2.3×10-2 without using any chiral inducers. Achiral solvents of hydrochloric acid (HCl) and N, N-dimethylformamide (DMF) infiltrate the crystal lattice via asymmetric hydrogen bonding, distorting the perovskite structure to induce the "intrinsic" chirality. Surprisingly, additional insertion of Cs+ cation to substitute partial (CH3)2NH2 + transforms the chiral space group to achiral but the crystal maintains chiroptical activity. Further doping of Sb3+ stimulates strong photoluminescence as a result of self-trapped excitons (STEs) formation without disturbing the crystal framework. The chiral perovskites of indium-antimony chlorides embedded on LEDs chips demonstrate promising potential as CPL emitters. Our work presents rare cases of chiroptical activity of highly luminescent perovskites from only achiral building blocks via spontaneous resolution as a result of symmetry breaking.
RESUMO
In the title complex, [Co(C(13)H(14)N(3)O(3))(2)(H(2)O)(2)], the Co(II) atom has a distorted octa-hedral coordination, formed by four N atoms from two (±)-2-(5-isopropyl-5-methyl-4-oxo-4,5-dihydro-1H-imidazol-2-yl)nicotinate ligands and two O atoms from two water mol-ecules. Intra-molecular N-Hâ¯O and O-Hâ¯O hydrogen bonds are present. In the crystal, inter-molecular O-Hâ¯O hydrogen bonds link the complex mol-ecules into a chain along [010].
RESUMO
In the title compound, [Mn(C(13)H(14)N(3)O(3))(2)(H(2)O)(2)], the Mn(II) ion is coordinated by four N atoms from two (±)-2-(5-isopropyl-5-methyl-4-oxo-4,5-dihydro-1H-imidazol-2-yl)nicotinate ligands and two water mol-ecules in a distorted octa-hedral environment. Inter-molecular O-Hâ¯O hydrogen bonds lead to a chain along [010]. Intra-molecular N-Hâ¯O and O-Hâ¯O hydrogen bonds are observed.
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The Zn atom in the title compound, [Zn(C(7)H(5)O(2))(2)(C(12)H(8)N(2))(H(2)O)], is five-coordinate in a distorted trigonal-bipyramidal coordination environment involving two O atoms of two monodentate benzoates, two N atoms of a 1,10-phenanthroline mol-ecule and one O atom of a water mol-ecule. The axial positions are occupied by a carboxyl-ate O atom from the benzoate ligand and an N atom from the 1,10-phenanthroline ligand [N-Zn-O = 146.90â (7)°]. The water mol-ecule forms an intra-molecular O-Hâ¯O hydrogen bond; an inter-molecular O-Hâ¯O hydrogen bond gives rise to a dimer.
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The authors investigated the efficiency and chromatic-stability characteristics of organic light emitting devices (OLEDs) with ultra-thin yellow emissive layers of 0.1 nm 5,6,11,12,-tetraphenylnaphthacene (rubrene) and hole block layer of BCP. The OLEDs with double thin rubrene layers and BCP layer were found to exhibit a high luminance and electroluminescence (EL) efficiency. The maximum EL efficiency and luminance reached 6. 35 cd x A(-1) at 6 V and 7 068 cd x m(-2) at 10 V respectively. Moreover, Commission International De L'Eclairage (CIE) coordination maintained unchanged (0.49, 0.49) in the wide range of applied voltages. The enhanced efficiency and good chromatic stability were attributed to a balanced injection and transport of electrons and holes and the expected confinement and balanced recombination of the emission region in the ultra-thin rubrene layers.
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Excessive extracellular matrix degradation caused by the hyperfunction of matrix metalloproteinases (MMPs) has been implicated in the failure of pressure ulcers healing. EMMPRIN, as a widely expressed protein, has emerged as an important regulator of MMP activity. We hypothesize that EMMPRIN affects the process of pressure ulcer healing by modulating MMP activity. In the rat pressure ulcer model, the expression of EMMPRIN in ulcers detected by Western blot was elevated compared with that observed in normal tissue. To investigate the role of EMMPRIN in regulating ulcer healing, specific antibodies against EMMPRIN were used via direct administration on the pressure ulcer. Local blockage of EMMPRIN resulted in a poor ulcer healing process compared with control ulcers, which was the opposite of our expectation. Furthermore, inhibiting EMMPRIN minimally impacted MMP activity. However, the collagen content in the pressure ulcer was reduced in the EMMPRIN treated group. Angiogenesis and the expression of angiogenic factors in pressure ulcers were also reduced by EMMPRIN local blockage. The results in the present study indicate a novel effect of EMMPRIN in the regulation of pressure ulcer healing by controlling the collagen contents and angiogenesis rather than MMPs activity.
Assuntos
Anticorpos/farmacologia , Proteínas Sanguíneas/antagonistas & inibidores , Úlcera por Pressão/metabolismo , Pele/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Proteínas Angiogênicas/metabolismo , Animais , Basigina/imunologia , Basigina/metabolismo , Proteínas Sanguíneas/imunologia , Proteínas Sanguíneas/metabolismo , Colágeno/metabolismo , Modelos Animais de Doenças , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Neovascularização Fisiológica , Úlcera por Pressão/imunologia , Úlcera por Pressão/patologia , Ratos Sprague-Dawley , Pele/irrigação sanguínea , Pele/imunologia , Pele/metabolismo , Pele/patologia , Fatores de TempoRESUMO
OBJECTIVE: To express human osteoprotegerin (OPG) in E. Coli and analyze its bioactivity in vitro. METHODS: Synthetic oligonucleotides were used to amplify human OPG gene by RT-PCR from total RNA of human osteosarcoma cell line MG63. The OPG cDNA coding for 380 amino acid residues was inserted into prokaryotic expression vector pRSET-A, transformed into competent E. Coli BL21, and induced by 0.1 mmol/l IPTG. SDS-PAGE and Western blot were performed to identify OPG-6His fusion protein. After purified by affinity chromatography, 1,000 microg/L or 1,500 microg/L of OPG-6His were added into the mouse bone marrow cells culture medium. The number of tartrate-resistant acid phophatase (TRAP)-positive multinucleated cells and resorption pits were counted to assess the bioactivity of expression products. RESULTS: The sequence of OPG mature peptide encoding cDNA obtained in this experiment was as same as reported. SDS-PAGE showed 24% of total bacterial protein was of OPG-6His fusion protein. Western blot assay demonstrated that the molecular weight of recombinant protein was about 46 KD and could react specifically with human anti-OPG antibody. The mouse bone marrow cells were induced by 1alpha, 25-dihydroxyvitaminD3 (10(-8) mol/L) and Dexamethasone (10(-7) mol/L) to form osteoclastic-like multinucleated cells. 1,500 microg/L of purified OPG-6His protein could decrease the number of resorption pits and TRAP-positive multinucleated cells in vitro (P < 0.05), but it didn't show the same effects when the concentration of OPG-6His fusion protein was of 1,000 microg/L. CONCLUSIONS: Human OPG-6His fusion protein is expressed and purified in E. Coli. The expression products have moderate inhibitory effects on osteoclast differentiation and bone resorption in vitro only when excessive amount of proteins are added into the culture medium, indicating that prokaryotic expression of fuctionalal OPG protein awaits further investigation.
Assuntos
Escherichia coli/genética , Glicoproteínas/genética , Receptores Citoplasmáticos e Nucleares/genética , Proteínas Recombinantes de Fusão/biossíntese , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Clonagem Molecular , Glicoproteínas/biossíntese , Humanos , Osteoclastos/efeitos dos fármacos , Osteoclastos/fisiologia , Osteoprotegerina , Receptores Citoplasmáticos e Nucleares/biossíntese , Receptores do Fator de Necrose Tumoral , Proteínas Recombinantes de Fusão/farmacologiaRESUMO
The OPG/RANKL/RANK system plays an important role in osteoclastogenesis and represents a great progress in bone biology. RANKL, which expresses on the surface of osteoblast/stromal cells and activated T cells, binds to RANK on the osteoclastic precursors or mature osteoclasts, and promotes osteoclastogenesis and bone resorption. While osteoprotegerin (OPG), which is expressed by osteoblasts/stromal cells, strongly inhibits bone resorption by binding to its ligand RANKL and thereby blocks the interaction between BANKL and RANK. A number of cytokines and hormones exert their effects on bone metabolism by regulating the OPG/RANKL ratio in the bone marrow microenvironment. RANK is also expressed on mammary epithelial cells and RANKL expression in these cells is induced by pregnancy hormones, RANKL and RANK are essential for the formation of the lactating mammary gland and the transmission of maternal calcium to neonates in mammalian species. Modulation of these systems provides a unique opportunity to develop novel therapeutics to inhibit bone loss in osteoporosis, rheumatoid arthritis, and bone metastasis of cancer. Further research should be focused on the cooperation of OPG/RANKL/RANK system with other signal pathways and the interactions among bone remodeling, immune system and endocrinology system. Currently, the development of OPG analogues or compounds which may stimulate OPG expression is becoming an attractive industry which may be profitable to both patients and manufacturers.
Assuntos
Reabsorção Óssea/imunologia , Reabsorção Óssea/metabolismo , Osteoprotegerina/metabolismo , Ligante RANK/metabolismo , Receptor Ativador de Fator Nuclear kappa-B/metabolismo , Animais , Humanos , Osteoclastos/citologia , Osteoclastos/metabolismo , Osteoclastos/patologia , Osteogênese/efeitos dos fármacos , Osteogênese/genética , Osteogênese/imunologia , Osteoprotegerina/fisiologia , Ligante RANK/fisiologia , Receptor Ativador de Fator Nuclear kappa-B/farmacologia , Receptor Ativador de Fator Nuclear kappa-B/fisiologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologiaRESUMO
Functional analysis of new genes is playing a central role in postgenomic era. Here we reviewed several main strategies including bioinformatics, gene transduction, antisense technology, certain gene silence induced by RNA interference (RNAi), transgene and gene knockout and artificial chromosome transduction.
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Biologia Computacional/métodos , Genes/fisiologia , Transdução Genética/métodos , Animais , HumanosRESUMO
OBJECTIVE: To construct a co-expressing vector of human bone morphogenetic protein 2 (BMP-2) and osteoprotegerin (OPG) and to determine the expression of BMP-2 and OPG in myoblast C2C12. METHODS: Using the isolated total RNA from osteosacoma cell line MG63 as a template, the cDNA encoding region of human OPG was amplified by reverse transcription-polymerase chain reaction (RT-PCT) method and cloned into sites EcoR 1 and BamH I of mammalian expressing vector pIRES2-EGFP, and the cDNA encoding region of human BMP-2 was cloned into endonucleases site BstX I. Then the recombinant plasmid pIRES2-BMP-2-OPG was transformed into C2C12 cell line, the expression of OPG and BMP-2 were determined by Western blot assay. RESULTS: The sequence of OPG cDNA obtained was the same as that reported, recombinant plasmid pIRES2-BMP-2-OPG was constructed successfully. Human OPG and BMP-2 co-expression cell line C2C12 was selected and confirmed by Western blot analysis. CONCLUSION: The co-expressing vector of OPG and BMP-2 is constructed and can expressed stably in myoblast C2C12. The co-expression of human OPG and BMP-2 may be logical approach for treatment of osteoporosis and bone metastasis.
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Proteínas Morfogenéticas Ósseas/biossíntese , Glicoproteínas/biossíntese , Mioblastos/metabolismo , Receptores Citoplasmáticos e Nucleares/biossíntese , Fator de Crescimento Transformador beta , Animais , Proteína Morfogenética Óssea 2 , Proteínas Morfogenéticas Ósseas/genética , Diferenciação Celular , Células Cultivadas , Escherichia coli , Expressão Gênica , Vetores Genéticos , Glicoproteínas/genética , Humanos , Mioblastos/citologia , Osteoprotegerina , Receptores Citoplasmáticos e Nucleares/genética , Receptores do Fator de Necrose Tumoral , Proteínas Recombinantes , TransfecçãoRESUMO
OBJECTIVE: To investigate the styles and affecting factors of bone union after massive frozen allografting for skeletal reconstruction owing to excision of bone tumor. METHODS: From 1992 to 1999, 85 patients suffering from bone malignant tumor were given the excision of large bone segment and treated with allografting in different methods of operation: large bone allografts with condylar articular surface in 16 cases, osteoarticular allografts in 57 cases, bone allografts in combination with prosthetic replacement of hip in 9 cases, and prosthetic replacement of knee in 3 cases. The average follow-up was 2 years and 9 months. The union time and styles of host-donor junction were determined by X-ray characters, and the results of operations were assessed according to Enneking's functional evaluation system of reconstructive procedures after surgical treatment of tumors for the musculoskeletal system. RESULTS: There were 4 kinds of basic bone union styles by the X-ray characters, there were no significant difference in the time span of bone union after fixation with different methods. Of the 85 fresh-frozen allografting procedures, more than 80% of the patients were treated with interlocked intramedullary nail and allograft-prosthesis combination, and the overall result was excellent and good. Sufficient blood supply was important for host-donor junction healing, but the function of immune response was uncertain. CONCLUSION: There were different styles of bone union after massive allografting. The recommended operative methods for massive allografts are stable internal fixation, sufficient blood supply, soft tissue repair and periosteal flap coverage.
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Neoplasias Ósseas/cirurgia , Transplante Ósseo , Procedimentos de Cirurgia Plástica/métodos , Adolescente , Adulto , Idoso , Artroplastia/métodos , Transplante Ósseo/fisiologia , Criança , Feminino , Congelamento , Humanos , Prótese Articular , Masculino , Pessoa de Meia-Idade , Radiografia , Tíbia/diagnóstico por imagem , Tíbia/cirurgia , Transplante HomólogoRESUMO
OBJECTIVE: To review the current concepts of gene therapy approaches mediated by adenovirus vectors for bone trauma and bone disease. METHODS: The recent literature concerned gene therapy mediated by adenovirus vectors was reviewed, which provides new insights into the treatments of bone trauma and bone disease. RESULTS: Adenovirus vectors was efficient, achieved high expression after transduction, and could transfer genes to both replicating and nonreplicating cells, such as osteoblasts, osteoclasts, fibroblasts, chondrocytes, bone marrow stromal cells, etc. Gene therapy mediated by adenovirus vectors achieved affirmative results in enhancing bone union and in curing bone diseases, such as osteoporosis and rheumatoid arthritis. CONCLUSION: Gene therapy mediated by adenovirus offers an exciting avenue for treatment of bone trauma and bone diseases.
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Adenoviridae/genética , Doenças Ósseas/terapia , Terapia Genética/métodos , Vetores Genéticos , Fraturas Ósseas/terapia , Técnicas de Transferência de GenesRESUMO
Using the isolated total RNA from osteosacoma cell line MG63, the cDNA encoding human OPG was amplified by RT-PCR. A recombinant adenoviral vector carrying cDNA of OPG was constructed and OPG expression in mouse myoblast C2C12 cells was confirmed by Western blot and ELISA. The secreted expression of OPG protein persisted more than 6 weeks in vitro, and the growth of C2C12 cells infected by recombinant adenoviral were in good state. Osteoclasts derived from mouse bone marrow cells infected with recombinant adenoviral made less number of TRAP positive cells and resorption pits formed on dentine slices.