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1.
Eur Radiol ; 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38231392

RESUMO

OBJECTIVE: To build and merge a diagnostic model called multi-input DenseNet fused with clinical features (MI-DenseCFNet) for discriminating between Staphylococcus aureus pneumonia (SAP) and Aspergillus pneumonia (ASP) and to evaluate the significant correlation of each clinical feature in determining these two types of pneumonia using a random forest dichotomous diagnosis model. This will enhance diagnostic accuracy and efficiency in distinguishing between SAP and ASP. METHODS: In this study, 60 patients with clinically confirmed SAP and ASP, who were admitted to four large tertiary hospitals in Kunming, China, were included. Thoracic high-resolution CT lung windows of all patients were extracted from the picture archiving and communication system, and the corresponding clinical data of each patient were collected. RESULTS: The MI-DenseCFNet diagnosis model demonstrates an internal validation set with an area under the curve (AUC) of 0.92. Its external validation set demonstrates an AUC of 0.83. The model requires only 10.24s to generate a categorical diagnosis and produce results from 20 cases of data. Compared with high-, mid-, and low-ranking radiologists, the model achieves accuracies of 78% vs. 75% vs. 60% vs. 40%. Eleven significant clinical features were screened by the random forest dichotomous diagnosis model. CONCLUSION: The MI-DenseCFNet multimodal diagnosis model can effectively diagnose SAP and ASP, and its diagnostic performance significantly exceeds that of junior radiologists. The 11 important clinical features were screened in the constructed random forest dichotomous diagnostic model, providing a reference for clinicians. CLINICAL RELEVANCE STATEMENT: MI-DenseCFNet could provide diagnostic assistance for primary hospitals that do not have advanced radiologists, enabling patients with suspected infections like Staphylococcus aureus pneumonia or Aspergillus pneumonia to receive a quicker diagnosis and cut down on the abuse of antibiotics. KEY POINTS: • MI-DenseCFNet combines deep learning neural networks with crucial clinical features to discern between Staphylococcus aureus pneumonia and Aspergillus pneumonia. • The comprehensive group had an area under the curve of 0.92, surpassing the proficiency of junior radiologists. • This model can enhance a primary radiologist's diagnostic capacity.

2.
Mitochondrial DNA B Resour ; 6(10): 2830-2831, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34514143

RESUMO

The Red Keelback (Pseudagkistrodon rudis Boulenger, 1906) is widely distributed in the southern of China. The complete mitochondrial genome (mitogenome) of P. rudis was determined for the first time by using next-generation sequencing. The size of assembled mitogenome for P. rudis was 19,150 bp, which included 13 protein coding genes (PCGs), 22 tRNAs, two rRNAs and two control regions (d-loop1 and d-loop2). The Bayesian tree showed that P. rudis and Rhabdophis tigrinus have a closed relationship. These results can provide data for phylogeny and molecular classification of the genus.

3.
Nanoscale ; 13(20): 9172-9176, 2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-33982740

RESUMO

There have been many new methods for synthesizing novel nanomaterials with unique functions. Herein, a novel strategy to form fluorescent nanoparticles in situ has been developed, and it can be applied to efficiently sense Hg2+ in living cells and also separate Hg2+ from water.

4.
Mitochondrial DNA B Resour ; 6(2): 428-429, 2021 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-33659700

RESUMO

Paramesotriton aurantius (Caudata: Salamandridae) is a new species that found in southeastern China. Its complete mitochondrial genome (mitogenome) sequence was 16,313 bp in length with with A + T contents of 60.9%, and contained 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, one control region (D-loop), and one non-coding region. Our molecular tree showed that P. aurantius was positioned near P. hongkongensis, and formed a clade with other Paramesotriton species. The first complete mitogenome sequence of P. aurantius could provided fundamental data for resolving phylogenetic and genetic problems related to genus Paramesotriton.

6.
J Hazard Mater ; 382: 121091, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31472465

RESUMO

In this study, we proposed to apply an integrated process which is comprised of in situ ozonation, ceramic membrane filtration (CMF) and biologically active carbon (BAC) filtration to wastewater reclamation for indirect potable reuse purpose. A pilot-scale (20 m3/d) experiment had been run for ten months to validate the prospect of the process in terms of treatment performance and operational stability. Results showed that the in situ O3 + CMF + BAC process performed well in pollutant removal, with chemical oxygen demand, ammonia, nitrate nitrogen, total phosphorus and turbidity levels in the treated water being 5.1 ±â€¯0.9, 0.05 ±â€¯0.01, 10.5 ±â€¯0.8, <0.06 mg/L, and <0.10 NTU, respectively. Most detected trace organic compounds were degraded by>96%. This study demonstrated that synergistic effects existed in the in situ O3 + CMF + BAC process. Compared to pre-ozonation, in situ ozonation in the membrane tank was more effective in controlling membrane fouling (maintaining operational stability) and in degrading organic pollutants, which could be attributed to the higher residual ozone concentration in the tank. Because of the removal of particulate matter by CMF, water head loss of the BAC filter increased slowly and prolonged the backwashing interval to 30 days. BAC filtration was also effective in removing ammonia and N-nitrosodimethylamine from the ozonated water.


Assuntos
Carvão Vegetal/química , Filtração/métodos , Oxidantes/química , Ozônio/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Amônia/química , Cafeína/química , Cerâmica , DEET/química , Diterpenos/química , Membranas Artificiais , Nitrogênio/química , Fósforo/química , Teofilina/química , Águas Residuárias
7.
Medicine (Baltimore) ; 97(39): e11550, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30278479

RESUMO

The clinical significance of palliative interventional therapy in the management of patients with advanced hilar cholangiocarcinoma (HCCA; stages III-IV) has yet to be studied. The present work was aimed to compare the clinical outcomes of the patients treated with surgery or interventional therapy.A total of 90 patients with advanced HCCA, who admitted Fuyang First People's Hospital from May 2015 to February 2016, were enrolled. Forty-five of them were assigned to the experimental group receiving biliary drainage as the interventional therapy, and the remaining 45 patients were designated as the conventional group receiving radical/palliative surgery. Before and after the treatment total bilirubin from blood was measured. The length of treatment and medical cost were also examined. All patients were followed up for at least 1 year after the treatment.For both the experimental and conventional groups, the serum bilirubin levels after treatment were significantly lower than those before treatment (P < .05); however, no significant differences between groups were seen. There were no significant differences between experimental and conventional groups in the incidence of postoperative complications and survival outcomes. Of note, the length of treatment of the experimental group was substantially shorter than that of the conventional group (P < .05). The medical expense of the experimental group was only about one-third of that of the conventional group (P < .05).Although the interventional therapy does not improve patients' survivals and reduce the incidence of complications, it significantly shortens the treatment length, reducing substantially the medical expense. This finding provides new insights into the treatment strategy for patients with advanced HCCA.


Assuntos
Neoplasias dos Ductos Biliares/cirurgia , Colangiocarcinoma/cirurgia , Drenagem/métodos , Cuidados Paliativos/métodos , Adulto , Idoso , Bilirrubina/sangue , Drenagem/efeitos adversos , Feminino , Seguimentos , Custos de Cuidados de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Taxa de Sobrevida , Resultado do Tratamento , Adulto Jovem
8.
Zhongguo Zhong Yao Za Zhi ; 40(24): 4908-13, 2015 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-27245042

RESUMO

Totally 96 elderly patients with spleen-kidney Yang deficiency type hypertension were selected in this study. Patients were randomly divided into study and control group. It was treated with the Jingui Shenqi pill combined nifedipine sustained-release tablets in the study group and only nifedipine sustained-release tablets for the control group. Meanwhile, the clinical features including reducing blood pressure, blood lipid and traditional Chinese medicine (TCM) syndromes of the two groups were observed pre and post treatment. Finally, the results showed that it could significantly reduce the hypertensive, hyperlipidemia and TCM syndromes in the study group compared with the control group (P < 0.05), which indicated that the combination of the Jingui Shenqi pill with nifedipine sustained-release tablets was effective for the patients with hypertension with spleen-kidney Yang deficiency type, especially for decreasing TCM syndromes and the blood lipid.


Assuntos
Medicamentos de Ervas Chinesas/administração & dosagem , Hipertensão/tratamento farmacológico , Nefropatias/tratamento farmacológico , Medicina Tradicional Chinesa , Nifedipino/administração & dosagem , Esplenopatias/tratamento farmacológico , Deficiência da Energia Yang/tratamento farmacológico , Idoso , Quimioterapia Combinada , Feminino , Humanos , Masculino
9.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 21(5): 1211-4, 2013 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-24156436

RESUMO

This study was purposed to detect the alloantibodies against Factor VIII (FVIII) by ELISA for estimating the incidence of the alloantibodies against Factor VIII (FVIII) in patients with hemophilia A, and to investigate the relationship between factor VIIIC domain and alloantibodies. Total of 140 patients with hemophilia A and 80 normal controls were enrolled in this study, among them plasma FVIII level of 84 patients was less than 1%, plasma FVIII level of 34 patients was between 1% and 5%, and plasma FVIII level of 22 patients was more than 5%. All patients were treated with plasma-derived FVIII concentrate or plasma before. The ELISA plate was coated with McAb (SZ-132) against FVIII prepared in our laboratory, then human recombinant FVIII concentrates were applied. After incubation in room temperature for 2 hours, diluted plasma samples and HRP-conjugated goat anti-human IgG were added successively, finally A490 was recorded. The threshold of alloantibody of patient plasma was set as mean value>3 SD more than control. The plate was coated with antibody against His, then human recombinant FVIII-C1C2 prepared in our laboratory was added. After incubation in room temperature for 2 hours, diluted plasma samples and HRP-conjugated goat anti-human IgG were added successively, finally A490 were recorded. The threshold was set as the mean value>3 SD more than control. The results showed that the alloantibodies against FVIII were found in 56 patients (40%) by ELISA, and 82.1% (46/56) of this kind of alloantibody could interact with the C domain of FVIII. It is concluded that C domain of FVIII is one of the primary binding sites for the alloantibodies against FVIII in Chinese patients with hemophilia A.


Assuntos
Fator VIII/imunologia , Hemofilia A/sangue , Hemofilia A/imunologia , Isoanticorpos/sangue , Adolescente , Adulto , Sítios de Ligação de Anticorpos , Estudos de Casos e Controles , Criança , Pré-Escolar , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Domínios e Motivos de Interação entre Proteínas , Adulto Jovem
10.
Zhonghua Wai Ke Za Zhi ; 51(4): 354-7, 2013 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-23895759

RESUMO

OBJECTIVE: To investigate the feasibility and safety of video-assisted thoracoscopic esophagectomy for esophageal carcinoma and gastro-esophageal anastomosis in right thoracic cavity. METHODS: The clinical data of 120 patients who underwent esophagectomy for esophageal carcinoma and gastro-esophageal anastomosis in right thoracic cavity from March to December 2011 was analyzed retrospectively. In the video-assisted thoracoscopic surgery group, there were 60 patients [41 male and 19 female patients with aver age of (62 ± 7) years old] who underwent video-assisted thoracoscopic esophagectomy for esophageal carcinoma and gastro-esophageal anastomosis in right thoracic cavity. In the routine thoracotomy group, there were 60 patients [39 male and 21 female patients with aver age of (62 ± 9) years old] who underwent routine thoracotomy esophagectomy for esophageal carcinoma and gastro-esophageal anastomosis in right thoracic cavity. Operation time, intra-operative blood loss, postoperative total thoracic drainage in 3 days, total number of harvested lymph nodes, hospitalization, cost of hospitalization and complications were compared between the two groups. RESULT: The operations were carried out successfully in two groups. There was no perioperative death in all patients. There was no statistical difference in intra-operative blood loss, postoperative total thoracic drainage and cost of hospitalization between the two groups. Operation time of rideo-assisted thoracoscopic surgery group was significantly longer than that of thoracotomy group ((188 ± 38) minutes vs. (138 ± 50) minutes, t = 6.171, P = 0.000), but postoperative hospitalization was significantly lower ((14 ± 3) d vs. (18 ± 6) d, t = -4.093, P = 0.000) and total number of harvested lymph nodes was lower (17 ± 9 vs. 21 ± 11, t = -2.058, P = 0.042). There was significantly statistical difference in total postoperative main complication (25.0% vs. 48.3%, χ(2) = 7.033, P = 0.008). And postoperative incisional infection of VATE group patients was significantly lower than that of thoracotomy group patients (6.7% vs. 25.0%, χ(2) = 7.566, P = 0.006). CONCLUSIONS: Video-assisted thoracoscopic esophagectomy for esophageal carcinoma and gastro-esophageal anastomosis in right thoracic cavity is technically feasible and safe, with minimized trauma and quick recovery. The recent result is satisfactory.


Assuntos
Anastomose Cirúrgica/métodos , Neoplasias Esofágicas/cirurgia , Esofagectomia/métodos , Cirurgia Torácica Vídeoassistida , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Excisão de Linfonodo , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Toracotomia
11.
Immunol Lett ; 148(2): 151-62, 2012 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-23018031

RESUMO

Psoriasis is a common chronic inflammatory skin disorder with dysregulation of miRNAs. The expression pattern of miR-146a and target gene IRAK1 in lesions and PBMCs of plaque psoriasis remains unclear. In our study, we found the expression of miR-146a was up-regulated both in lesions and PBMCs of psoriatic patients, and positively correlated with IL-17 expression, whereas the target gene IRAK1 expression was expressed differentially in lesions and peripheral blood. Inability of miR-146a inhibiting target gene IRAK1 may contribute to the persistent inflammation in lesions of psoriasis.


Assuntos
Quinases Associadas a Receptores de Interleucina-1/metabolismo , Interleucina-17/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Psoríase/metabolismo , Adulto , Feminino , Regulação da Expressão Gênica , Humanos , Interferon gama/sangue , Quinases Associadas a Receptores de Interleucina-1/genética , Interleucina-17/sangue , Masculino , Psoríase/imunologia , Pele/metabolismo , Fator de Necrose Tumoral alfa/sangue
12.
Artigo em Chinês | MEDLINE | ID: mdl-21287500

RESUMO

OBJECTIVE: To investigate the keratin 17 gene (KRT17) mutation in a pedigree with pachyonychia congenita type 2 (PC-II). METHODS: DNA was extracted from the blood samples of the patients, unaffected members of the pedigree, and 100 unrelated healthy controls. PCR was performed to amplify the hot spots in KRT17 gene. PCR products were directly sequenced to detect mutation. RESULTS: A heterozygous 296T-->C mutation was found in all the affected members of this family, which resulted in the substitution of leucine by proline in codon 99 (L99P) in the 1A domain of the KRT17, but not in the healthy individuals from the family and the 100 unrelated controls. CONCLUSION: The mutation of KRT17 may play a major role in the pathogenesis of this pedigree with pachyonychia congenita type 2.


Assuntos
Povo Asiático/genética , Queratina-17/genética , Mutação , Paquioníquia Congênita/genética , Adulto , Sequência de Bases , China/etnologia , Humanos , Masculino , Dados de Sequência Molecular , Paquioníquia Congênita/etnologia , Análise de Sequência de DNA
13.
J Cutan Pathol ; 37(3): 371-5, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19615027

RESUMO

BACKGROUND: Porokeratosis (PK) is a heterogeneous group of keratinization disorders that exhibit similarities with psoriasis at both the clinical and molecular levels. METHODS: The transcript levels of keratin (KRT) 6A, 16, 17, S100A7, A8, A9, p53 and three candidate genes (i.e. SART3, SSH1 and ARPC3) were reassessed in pairwise lesional and uninvolved skin from nine patients with PK by real-time quantitative polymerase chain reaction (RTQ-PCR). RESULTS: The results of RTQ-PCR confirmed that KRT6A, 16, S100A7, A8 and A9 (p = 0.008) were mostly up-regulated in the lesional skin when compared with uninvolved skin. Different from the microarray data, there was no significant difference observed in KRT17 expression patterns between lesional and normal-appearing skin (p = 0.066). No statistical difference was observed in p53 and three candidate genes' expression patterns between lesional and uninvolved skin. CONCLUSIONS: In the present study, 9 of the 10 gene expression measured by RTQ-PCR in PK were statistically comparable to microarray data. KRT6A was identified as specific biomarker for porokeratotic keratinocytes, as it was the most significantly up-regulated gene in the nine patient samples.


Assuntos
Poroceratose/genética , Pele/metabolismo , Idade de Início , Feminino , Perfilação da Expressão Gênica , Humanos , Queratinócitos/metabolismo , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Poroceratose/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise Serial de Tecidos
14.
Avian Dis ; 52(3): 507-12, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18939644

RESUMO

The objective of this study was to understand the distribution patterns and levels of Salmonella Enteritidis (SE) in the immune organs of ducklings after oral challenge. We conducted serovar-specific real-time polymerase chain reaction (PCR) for SE to detect the genomic DNA of SE in the blood and immune organs, including the bursa of Fabricius, thymus, spleen, and Harderian gland, from ducklings after oral challenge at different time points. The results showed that SE was consistently detected in all the samples. The Harderian gland and spleen tested positive at 8 hr postinoculation (PI). The organism was detected in the blood, bursa of Fabricius, and thymus at 10 hr PI. The copy number of SE DNA in each tissue reached a peak at 24-36 hr PI. The spleen, blood, and Harderian gland contained high concentrations of SE, whereas the thymus and bursa of Fabricius had low concentrations. SE populations began to decrease and were not detectable at 2 days PI, but they were still present up to 9 days PI in the spleen, without producing any apparent symptoms. To validate these results, the indirect immunofluorescent antibody (IFA) technique was used, and the IFA results were similar to those of the fluorescent quantitative-PCR. In conclusion, the results provided insight into the SE life cycle in the immune organs; furthermore, the Harderian gland and spleen were determined to be the primary sites of invasion among the immune organs of normal ducklings after oral SE challenge. This study will help in understanding the pathogenesis of SE infection in vivo and may help in the development of a live Salmonella vaccine in the future.


Assuntos
Patos , Sistema Imunitário/microbiologia , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Salmonella enteritidis/genética , Animais , Técnica Indireta de Fluorescência para Anticorpo , Reação em Cadeia da Polimerase/métodos
15.
J Cutan Pathol ; 35(11): 1058-62, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18727663

RESUMO

BACKGROUND: Porokeratosis (PK) represents a heterogeneous group of disorders of keratinization and has a wide variety of clinical manifestations. PK may exhibit similarities with psoriasis at both clinical and molecular levels. The genetic basis and pathogenesis for PK remain elusive. METHODS: We studied the transcriptional profiles of three pairwise lesional and uninvolved skin biopsies from patients with different subtypes of PK using the Illumina BeadArray platform. RESULTS: A total of 37 upregulated genes were identified in our study, including wound-induced keratins, S100 calcium-binding protein genes involved in epidermal differentiation, as well as genes involved in mediating intercellular communication and the immune response. To our knowledge, this is the first study that characterizes the immune profile of PK lesions. CONCLUSIONS: Here, we report that keratinocytes (KCs)-harboring lesions have activated and overexpressed wound-induced keratin genes, which appear to be coregulated with other genes involved in mediating epidermal differentiation, intercellular communication and immunity. This study, from the perspective of gene profiling, supports that gene misregulation in PK mimics that of psoriasis. Our data indicate that the genes implicated in the T-cell-mediated immune response pathway and activation of KCs play a key role in the pathogenesis of PK.


Assuntos
Perfilação da Expressão Gênica , Queratinócitos/metabolismo , Queratinas/genética , Poroceratose/genética , Biomarcadores/metabolismo , Humanos , Queratinócitos/patologia , Queratinas/metabolismo , Masculino , Pessoa de Meia-Idade , Poroceratose/metabolismo , Poroceratose/patologia , RNA Mensageiro/análise , Regulação para Cima
17.
Zhongguo Dang Dai Er Ke Za Zhi ; 9(6): 526-8, 2007 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-18082030

RESUMO

OBJECTIVE: To detect plasma concentrations of vascular endothelial cell growth factor (VEGF) and tissue factor (TF) in children with acute lymphoblastic leukemia (ALL) and explore their clinical significance in ALL. METHODS: Thirty-three children with newly diagnosed ALL, including 18 cases of low risk, 7 cases of moderate risk and 8 cases of high risk, were enrolled in this study. Twenty-five patients received a complete remission and 8 cases were in non-remission after conventional remission induction chemotherapy. Plasma concentrations of VEGF and TF in the patients were detected using ELISA before and after treatment. Sixteen healthy children served as normal control group. RESULTS: Plasma concentrations of VEGF and TF in ALL patients before treatment were significantly higher than those in normal controls (P < 0.01). Plasma concentrations of VEGF and TF in the non-remission group before treatment were significantly higher than those in the remission group (P < 0.05) and the control group (P < 0.01). After treatment the plasma concentrations of VEGF and TF in the non-remission group were not significantly reduced and higher than those in the remission and the control groups (P < 0.01). There were significant differences in plasma concentrations of VEGF and TF among the low-risk, moderate-risk and high-risk groups before and after treatment (P < 0.05). Plasma concentrations of VEGF and TF in the high risk group were not significantly reduced after treatment and higher than those in the control group (P < 0.01). A linear correlation was noted between plasma VEGF and TF concentrations in ALL patients before treatment (r=0.50, P < 0.01). CONCLUSIONS: VEGF and TF play an important role in the development of ALL and may be useful to the evaluation of the severity and the outcome in ALL.


Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras/sangue , Tromboplastina/análise , Fator A de Crescimento do Endotélio Vascular/sangue , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/etiologia
19.
Inorg Chem ; 45(10): 3941-8, 2006 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-16676952

RESUMO

Three novel metal-organic architectures, [Ag3(bta)].1.5H2O (1), [Cd3(bta)2(H2O)7].5H2O (2), and [Cu11(bta)6(Hbta)2(H2O)10].29H2O (3), were obtained by reactions of the corresponding metal salts with a flexible tripodal ligand, benzene-1,3,5-triacetic acid (H3bta), and their structures were determined by single-crystal X-ray diffraction studies. The results revealed that, in complexes 1 and 2, the carboxylate groups of the bta3- ligand adopted varied coordination modes to link metal atoms and further to form three-dimensional structures with open channels occupied by water molecules, while in complex 3, for the first time, the flexible H3bta acted as a secondary building unit to generate a novel nanometer-sized metallocage, which is composed of a Cu(II) paddle wheel (square secondary building units) and bta3-/Hbta2- organic links (triangular secondary building units). The photoluminescence properties of complexes 1 and 2 were investigated, and the results showed that 2 exhibited photoluminescence in the solid state at room temperature.


Assuntos
Acetatos/química , Cádmio/química , Cobre/química , Compostos Organometálicos/química , Prata/química , Cristalografia por Raios X , Ligantes , Luminescência , Modelos Moleculares , Conformação Molecular
20.
Inorg Chem ; 45(7): 2896-902, 2006 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-16562945

RESUMO

Reactions of tripodal ligand 1,3,5-tris(imidazole-1-ylmethyl)-2,4,6-trimethylbenzene (L) with lanthanide metal salts and triethyl orthoformate led to the formation of six bowl-like dinuclear compounds [Ln2(L)(HL)(NO3)6(HCOO)].3CH3OH (Ln = Gd 1, Tb 2, Dy 3, Er 4, Yb 5, and Eu 6). The single-crystal X-ray diffraction analysis revealed that six complexes are isomorphous and isostructural and that the dinuclear molecules are further connected by hydrogen bonds and pi-pi interactions, resulting in 3D channel-like structures. The luminescence properties have been studied, and the results showed that the Tb(III) (2) and Eu(III) (6) complexes exhibited sensitized luminescence in the visible region and their luminescence lifetimes in powder and DMSO-d6 solution are in the range of milliseconds. The Yb(III) complex (5) emits typical near-infrared luminescence in DMSO-d6 solution. Variable-temperature magnetic susceptibility measurements of 1-6 showed that complex 1 (Gd) is nearly a paramagnet and complexes 2 (Tb), 3 (Dy), and 4 (Er) show the ferromagnetic coupling between magnetic centers, whereas the depopulation of the Stark levels in complexes 5 (Yb) and 6 (Eu) leads to a continuous decrease in (chi M)T when the sample is cooled from 300 to 1.8 K.


Assuntos
Imidazóis/química , Elementos da Série dos Lantanídeos/química , Magnetismo , Compostos Organometálicos/química , Compostos Organometálicos/síntese química , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Cristalização , Cristalografia por Raios X , Ligantes , Luminescência , Modelos Moleculares , Estrutura Molecular , Fotoquímica , Temperatura
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