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1.
Microorganisms ; 11(10)2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37894214

RESUMO

Prokaryotes, the earliest forms of life on Earth, play crucial roles in global biogeochemical processes in virtually all ecosystems. The ever-increasing amount of prokaryotic genome sequencing data provides a wealth of information to examine fundamental and applied questions through systematic genome comparison. Genomic features, such as genome size and GC content, and taxonomy-centric genomic features of complete prokaryotic genomes (CPGs) are crucial for various fields of microbial research and education, yet they are often overlooked. Additionally, creating systematically curated datasets that align with research concerns is an essential yet challenging task for wet-lab researchers. In this study, we introduce CPGminer, a user-friendly tool that allows researchers to quickly and easily examine the genomic features and taxonomy of CPGs and curate genome datasets. We also provide several examples to demonstrate its practical utility in addressing descriptive questions.

2.
Yeungnam Univ J Med ; 38(4): 289-307, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34411477

RESUMO

Avulsion injuries result from the application of a tensile force to a musculoskeletal unit or ligament. Although injuries tend to occur more commonly in skeletally immature populations due to the weakness of their apophysis, adults may also be subject to avulsion fractures, particularly those with osteoporotic bones. The most common sites of avulsion injuries in adolescents and children are apophyses of the pelvis and knee. In adults, avulsion injuries commonly occur within the tendon due to underlying degeneration or tendinosis. However, any location can be involved in avulsion injuries. Radiography is the first imaging modality to diagnose avulsion injury, although advanced imaging modalities are occasionally required to identify subtle lesions or to fully delineate the extent of the injury. Ultrasonography has a high spatial resolution with a dynamic assessment potential and allows the comparison of a bone avulsion with the opposite side. Computed tomography is more sensitive for depicting a tiny osseous fragment located adjacent to the expected attachment site of a ligament, tendon, or capsule. Moreover, magnetic resonance imaging is the best imaging modality for the evaluation of soft tissue abnormalities, especially the affected muscles, tendons, and ligaments. Acute avulsion injuries usually manifest as avulsed bone fragments. In contrast, chronic injuries can easily mimic other disease processes, such as infections or neoplasms. Therefore, recognizing the vulnerable sites and characteristic imaging features of avulsion fractures would be helpful in ensuring accurate diagnosis and appropriate patient management. To this end, familiarity with musculoskeletal anatomy and mechanism of injury is necessary.

3.
BMC Bioinformatics ; 21(1): 160, 2020 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-32349673

RESUMO

BACKGROUND: Cytochrome P450 monooxygenases (termed CYPs or P450s) are hemoproteins ubiquitously found across all kingdoms, playing a central role in intracellular metabolism, especially in metabolism of drugs and xenobiotics. The explosive growth of genome sequencing brings a new set of challenges and issues for researchers, such as a systematic investigation of CYPs across all kingdoms in terms of identification, classification, and pan-CYPome analyses. Such investigation requires an automated tool that can handle an enormous amount of sequencing data in a timely manner. RESULTS: CYPminer was developed in the Python language to facilitate rapid, comprehensive analysis of CYPs from genomes of all kingdoms. CYPminer consists of two procedures i) to generate the Genome-CYP Matrix (GCM) that lists all occurrences of CYPs across the genomes, and ii) to perform analyses and visualization of the GCM, including pan-CYPomes (pan- and core-CYPome), CYP co-occurrence networks, CYP clouds, and genome clustering data. The performance of CYPminer was evaluated with three datasets from fungal and bacterial genome sequences. CONCLUSIONS: CYPminer completes CYP analyses for large-scale genomes from all kingdoms, which allows systematic genome annotation and comparative insights for CYPs. CYPminer also can be extended and adapted easily for broader usage.


Assuntos
Sistema Enzimático do Citocromo P-450/análise , Sistema Enzimático do Citocromo P-450/metabolismo , Análise de Dados , Bases de Dados Genéticas , Genoma , Filogenia , Automação , Análise por Conglomerados , Fungos/genética , Redes Reguladoras de Genes , Software , Interface Usuário-Computador
4.
Korean J Radiol ; 20(6): 916-930, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31132817

RESUMO

OBJECTIVE: To investigate the relationships of T2*-corrected 6-echo Dixon volumetric interpolated breath-hold examination (VIBE) imaging-based fat fraction (FF) and R2* values with bone mineral density (BMD); determine their associations with sex, age, and menopause; and evaluate the diagnostic performance of the FF and R2* for predicting osteopenia and osteoporosis. MATERIALS AND METHODS: This study included 153 subjects who had undergone magnetic resonance (MR) imaging, including MR spectroscopy (MRS) and T2*-corrected 6-echo Dixon VIBE imaging. The FF and R2* were measured at the L4 vertebra. The male and female groups were divided into two subgroups according to age or menopause. Lin's concordance and Pearson's correlation coefficients, Bland-Altman 95% limits of agreement, and the area under the curve (AUC) were calculated. RESULTS: The correlation between the spectroscopic and 6-echo Dixon VIBE imaging-based FF values was statistically significant for both readers (pc = 0.940 [reader 1], 0.908 [reader 2]; both p < 0.001). A small measurement bias was observed for the MRS-based FF for both readers (mean difference = -0.3% [reader 1], 0.1% [reader 2]). We found a moderate negative correlation between BMD and the FF (r = -0.411 [reader 1], -0.436 [reader 2]; both p < 0.001) with younger men and premenopausal women showing higher correlations. R2* and BMD were more significantly correlated in women than in men, and the highest correlation was observed in postmenopausal women (r = 0.626 [reader 1], 0.644 [reader 2]; both p < 0.001). For predicting osteopenia and osteoporosis, the FF had a higher AUC in men and R2* had a higher AUC in women. The AUC for predicting osteoporosis was highest with a combination of the FF and R2* in postmenopausal women (AUC = 0.872 [reader 1], 0.867 [reader 2]; both p < 0.001). CONCLUSION: The FF and R2* measured using T2*-corrected 6-echo Dixon VIBE imaging can serve as predictors of osteopenia and osteoporosis. R2* might be useful for predicting osteoporosis, especially in postmenopausal women.


Assuntos
Densidade Óssea/fisiologia , Doenças Ósseas Metabólicas/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Osteoporose/diagnóstico por imagem , Adulto , Idoso , Algoritmos , Área Sob a Curva , Doenças Ósseas Metabólicas/diagnóstico , Doenças Ósseas Metabólicas/patologia , Suspensão da Respiração , Feminino , Humanos , Vértebras Lombares/patologia , Masculino , Menopausa/fisiologia , Pessoa de Meia-Idade , Osteoporose/diagnóstico , Osteoporose/patologia , Respiração
5.
Korean J Radiol ; 20(3): 469-478, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30799578

RESUMO

OBJECTIVE: To investigate the image quality, radiation dose, and intermodality agreement of cervical spine CT using spectral shaping at 140 kVp by a tin filter (Sn140-kVp) in comparison with those of conventional CT at 120 kVp. MATERIALS AND METHODS: Patients who had undergone cervical spine CT with Sn140-kVp (n = 58) and conventional 120 kVp (n = 49) were included. Qualitative image quality was analyzed using a 5-point Likert scale. Quantitative image quality was assessed by measuring the noise and attenuation within the central spinal canals at C3/4, C6/7, and C7/T1 levels. Radiation doses received by patients were estimated. The intermodality agreement for disc morphology between CT and MRI was assessed at C3/4, C5/6, C6/7, and C7/T1 levels in 75 patients who had undergone cervical spine MRI as well as CT. RESULTS: Qualitative image quality was significantly superior in Sn140-kVp scans than in the conventional scans (p < 0.001). At C7/T1 level, the noise was significantly lower and the decrease in attenuation was significantly less in Sn140-kVp scans, than in the conventional scans (p < 0.001). Radiation doses were significantly reduced in Sn140-kVp scans by 50% (effective dose: 1.0 ± 0.1 mSv vs. 2.0 ± 0.4 mSv; p < 0.001). Intermodality agreement in the lower cervical spine region tended to be better in Sn140-kVp acquisitions than in the conventional acquisitions. CONCLUSION: Cervical spine CT using Sn140-kVp improves image quality of the lower cervical region without increasing the radiation dose. Thus, this protocol can be helpful to overcome the artifacts in the lower cervical spine CT images.


Assuntos
Medula Cervical/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , Artefatos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador , Razão Sinal-Ruído
6.
Korean J Radiol ; 19(4): 752-757, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29962881

RESUMO

Objective: The purpose of this study was to describe the ultrasonographic findings of angioleiomyoma based on pathological subtypes. Materials and Methods: Thirty-nine patients with subcutaneous angioleiomyomas in the extremities were retrospectively reviewed by two radiologists and a pathologist. Sonographic images were analyzed to evaluate each tumor's anatomic location, size, shape, margin, heterogeneity, echogenicity, associated findings, and vascularity. Results: Angioleiomyomas were divided into 3 subtypes: capillary (n = 16), venous (n = 22), and cavernous (n = 1). The one cavernous angioleiomyoma was a hypoechoic mass with rich vascularity. Hypoechogenicity was more frequently observed for venous tumors (77.3%) than for capillary tumors (43.8%), and isoechogenicity was more frequently observed for capillary tumors (56.2%) than for venous tumors (22.7%). Moderate vascularity was more frequently observed for venous tumors (59.1%) than for capillary tumors (12.5%), and little vascularity was more frequently observed for capillary tumors (62.5%) than for venous tumors (13.6%). The aforementioned findings including echogenicity (p = 0.034) and vascularity (p = 0.003) were statistically significant. Conclusion: Awareness of sonographic findings of angioleiomyomas based on pathologic subtypes could be helpful for diagnosing angioleiomyoma and could increase diagnostic accuracy for superficial soft-tissue masses in our practice.


Assuntos
Angiomioma/patologia , Tumor de Músculo Liso/patologia , Ultrassonografia , Adulto , Idoso , Angiomioma/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tumor de Músculo Liso/diagnóstico por imagem
7.
Clin Imaging ; 51: 260-265, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29906783

RESUMO

PURPOSE: The purpose was to evaluate the clinical value of PETRA sequence for the diagnosis of internal derangement of the knee. MATERIALS AND METHODS: The major structures of the knee in 34 patients were evaluated and compared among conventional MRI findings, PETRA images, and arthroscopic findings. RESULTS: The specificities of PETRA with 2D FSE sequence were higher for meniscal lesions than those obtained when using 2D FSE alone. CONCLUSION: Using PETRA images along with conventional 2D FSE images can increase the accuracy of assessing internal derangements of the knee and, specifically, meniscal lesions.


Assuntos
Aumento da Imagem/métodos , Articulação do Joelho/patologia , Joelho/patologia , Imageamento por Ressonância Magnética/métodos , Menisco/patologia , Adolescente , Adulto , Idoso , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Adulto Jovem
8.
Ultrasonography ; 36(4): 321-335, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28535605

RESUMO

Ankle disorders are a relatively common pathological condition, and ankle injuries account for approximately 14% of sports-related orthopedic emergency visits. Various imaging modalities can be used to make a diagnosis in cases of ankle pain; however, ultrasound (US) has several benefits for the evaluation of ankle pain, especially in the tendons, ligaments, and nerves of the ankle. The purpose of this article is to review the common causes of ankle pathology, with particular reference to US features. In addition, the importance of a dynamic evaluation and a stress test with US is emphasized.

9.
J Am Chem Soc ; 139(12): 4540-4550, 2017 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-28263588

RESUMO

The dicationic complex [CpCo(azpy)(CH3CN)](ClO4)2 1 (azpy = phenylazopyridine) exhibits a reversible two-electron reduction at a very mild potential (-0.16 V versus Fc0/+) in acetonitrile. This behavior is not observed with the analogous bipyridine and pyrazolylpyridine complexes (3 and 4), which display an electrochemical signature typical of CoIII systems: two sequential one-electron reductions to CoII at -0.4 V and CoI at -1.0 to -1.3 V versus Fc0/+. The doubly reduced, neutral complex [CpCo(azpy)] 2 is isolated as an air-stable, diamagnetic solid via chemical reduction with cobaltocene. Crystallographic and spectroscopic characterization together with experimentally calibrated density functional theory calculations illuminate the key structural and electronic changes that occur upon reduction of 1 to 2. The electrochemical potential inversion observed with 1 is attributed to effective overlap between the metal d and the low-energy azo π* orbitals in the intermediary redox state and additional stabilization of 2 from structural reorganization, leading to a two-electron reduction. This result serves as a key milestone in the quest for two-electron transformations with mononuclear first-row transition metal complexes at mild potentials.

10.
Knee Surg Sports Traumatol Arthrosc ; 25(2): 374-382, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26607944

RESUMO

PURPOSE: Lateral meniscus allograft transplantation (LMAT) is a feasible surgical option for young meniscus-deficient patients. Although several studies have explored the factors that contribute to graft extrusion, they have not been fully elucidated. The aim of this study was to determine the various factors that contribute to graft extrusion. METHODS: Patients with knees that had received LMAT using a keyhole technique (n = 87 knees in 82 patients) were reviewed. The median age of these patients was 22 years (range 19-54 years), and the median postprocedural follow-up interval was 5 days (range 1-136 days). Twelve magnetic resonance imaging (MRI) measurement parameters (axial and coronal location of the bone block) that could potentially influence graft extrusion were evaluated, along with absolute graft extrusion and relative percentage of extrusion (RPE). RESULTS: A significant correlation was found between 8 of the 12 MRI measurement parameters and both the absolute extrusion and RPE (r = 0.241-0.438, p < 0.05). The absolute middle distance and depth of the bone block were independent predictors of the absolute extrusion (ß = 0.30 and 0.15, respectively; p < 0.05), and the relative middle distance and relative bone-block elevation were found to be predictors of RPE (ß = 2.29 and 1.44, respectively; p < 0.05). CONCLUSION: The rate of graft extrusions after LMAT was high in this study. Both the coronal and axial locations of the bone block were found to influence graft extrusion in LMAT. Therefore, correct positioning of the bone block, including in both the axial and coronal planes, is essential to minimize graft extrusion. Future studies need to investigate the long-term clinical outcome and longevity of extruded menisci after transplantation. LEVEL OF EVIDENCE: Therapeutic case series, Level IV.


Assuntos
Doenças das Cartilagens/cirurgia , Fibrocartilagem/transplante , Migração de Corpo Estranho/diagnóstico por imagem , Articulação do Joelho/diagnóstico por imagem , Meniscos Tibiais/cirurgia , Complicações Pós-Operatórias/diagnóstico por imagem , Adulto , Aloenxertos , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Transplante Homólogo , Adulto Jovem
11.
Eur J Radiol ; 85(8): 1351-65, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27423673

RESUMO

Meniscus allograft transplantation has been performed over the past 25 years to relieve knee pain and improve knee function in patients with an irreparable meniscus injury. The efficacy and safety of meniscus allograft transplantation have been established in numerous experimental and clinical researches. However, there is a lack of reviews to aid radiologists who are routinely interpreting images and evaluating the outcome of the procedures, and also meniscus allograft transplantation is not widely performed in most hospitals. This review focuses on the indications of the procedure, the different surgical techniques used for meniscus allograft transplantation according to the involvement of the lateral and medial meniscus, and the associated procedures. The postoperative radiological findings and surgical complications of the meniscus allograft transplantation are also described in detail.


Assuntos
Aloenxertos/transplante , Articulação do Joelho/cirurgia , Meniscos Tibiais/transplante , Aloenxertos/diagnóstico por imagem , Humanos , Articulação do Joelho/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Meniscos Tibiais/diagnóstico por imagem , Cuidados Pós-Operatórios , Complicações Pós-Operatórias/diagnóstico por imagem , Procedimentos de Cirurgia Plástica/métodos
12.
BMC Neurol ; 16: 73, 2016 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-27206611

RESUMO

BACKGROUND: The aim of this study was to develop an assessment tool for activities of daily living (ADL) from the perspective of patients with Parkinson's disease (PD) and examine the validity and reliability of the assessment. METHODS: A preliminary 45-item questionnaire was developed through intensive interviews with 54 patients with PD and administered to another group of 248 patients with PD. Based on clinical and statistical analyses, 20 ADL-items were selected. The final 20-item questionnaire was examined in the other group of 59 patients with PD. RESULTS: The new ADL questionnaire showed high internal consistency (Cronbach's α, 0.962-0.966) and acceptable test-retest reliability (0.632-0.984). Concurrent validity was shown as a significant positive correlation between the new ADL questionnaire and other ADL or clinical instruments. The Hoehn and Yahr stage showed the highest degree of correlation with the new ADL questionnaire, followed by the other ADL scales (Schwab and England ADL and the ADL subscore of the Unified Parkinson's Disease Rating Scale). Additionally, a regression analysis was conducted with the disease-specific quality of life questionnaire, and the new ADL questionnaire was the most powerful predictor of quality of life among the clinical instruments. CONCLUSIONS: The new ADL questionnaire is a valid tool for assessing ADL from the perspectives of patients with PD.


Assuntos
Atividades Cotidianas/psicologia , Doença de Parkinson/psicologia , Inquéritos e Questionários , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Valor Preditivo dos Testes , Psicometria , Qualidade de Vida
13.
BMC Evol Biol ; 15: 21, 2015 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-25880171

RESUMO

BACKGROUND: The bacterial genus Mycobacterium is of great interest in the medical and biotechnological fields. Despite a flood of genome sequencing and functional genomics data, significant gaps in knowledge between genome and phenome seriously hinder efforts toward the treatment of mycobacterial diseases and practical biotechnological applications. In this study, we propose the use of systematic, comparative functional pan-genomic analysis to build connections between genomic dynamics and phenotypic evolution in polycyclic aromatic hydrocarbon (PAH) metabolism in the genus Mycobacterium. RESULTS: Phylogenetic, phenotypic, and genomic information for 27 completely genome-sequenced mycobacteria was systematically integrated to reconstruct a mycobacterial phenotype network (MPN) with a pan-genomic concept at a network level. In the MPN, mycobacterial phenotypes show typical scale-free relationships. PAH degradation is an isolated phenotype with the lowest connection degree, consistent with phylogenetic and environmental isolation of PAH degraders. A series of functional pan-genomic analyses provide conserved and unique types of genomic evidence for strong epistatic and pleiotropic impacts on evolutionary trajectories of the PAH-degrading phenotype. Under strong natural selection, the detailed gene gain/loss patterns from horizontal gene transfer (HGT)/deletion events hypothesize a plausible evolutionary path, an epistasis-based birth and pleiotropy-dependent death, for PAH metabolism in the genus Mycobacterium. This study generated a practical mycobacterial compendium of phenotypic and genomic changes, focusing on the PAH-degrading phenotype, with a pan-genomic perspective of the evolutionary events and the environmental challenges. CONCLUSIONS: Our findings suggest that when selection acts on PAH metabolism, only a small fraction of possible trajectories is likely to be observed, owing mainly to a combination of the ambiguous phenotypic effects of PAHs and the corresponding pleiotropy- and epistasis-dependent evolutionary adaptation. Evolutionary constraints on the selection of trajectories, like those seen in PAH-degrading phenotypes, are likely to apply to the evolution of other phenotypes in the genus Mycobacterium.


Assuntos
Mycobacterium/genética , Mycobacterium/metabolismo , Biodegradação Ambiental , Evolução Biológica , Epistasia Genética , Transferência Genética Horizontal , Genes Bacterianos , Genômica , Mycobacterium/classificação , Filogenia , Hidrocarbonetos Policíclicos Aromáticos/metabolismo
14.
Dalton Trans ; 44(16): 7373-81, 2015 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-25799252

RESUMO

A highly electrophilic cationic Pd(II) complex, [Pd(MeCN)4][BF4]2 (1), brings about the preferential activation of the B-H bond in ammonia-borane (NH3·BH3, AB). At room temperature, the reaction between 1 in CH3NO2 and AB in tetraglyme leads to Pd nanoparticles and formation of spent fuels of the general formula MeNHxBOy as reaction byproducts, while 2 equiv. of H2 is efficiently released per AB equiv. at room temperature within 60 seconds. For a mechanistic understanding of dehydrogenation by 1, the chemical structures of spent fuels were intensely characterized by a series of analyses such as elemental analysis (EA), X-ray photoelectron spectroscopy (XPS), solid state magic-angle-spinning (MAS) NMR spectra ((2)H, (13)C, (15)N, and (11)B), and cross polarization (CP) MAS methods. During AB dehydrogenation, the involvement of MeNO2 in the spent fuels showed that the mechanism of dehydrogenation catalyzed by 1 is different from that found in the previously reported results. This AB dehydrogenation derived from MeNO2 is supported by a subsequent digestion experiment of the AB spent fuel: B(OMe)3 and N-methylhydroxylamine ([Me(OH)N]2CH2), which are formed by the methanolysis of the AB spent fuel (MeNHxBOy), were identified by means of (11)B NMR and single crystal structural analysis, respectively. A similar catalytic behavior was also observed in the AB dehydrogenation catalyzed by a nickel catalyst, [Ni(MeCN)6][BF4]2 (2).

15.
Dalton Trans ; 43(26): 10132-8, 2014 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-24875269

RESUMO

An ansa-zirconocene bearing methyl substituents at all positions adjacent to the bridgehead [(-C(Ph)HC(Ph)H-)(η(5)-2,5-Me2C5H2)2ZrCl2] (4) was prepared in high yields (78%) through the reductive dimerization of 1,4-dimethyl-6-phenylfulvene utilizing ZrCl2·DME generated in situ. The structure of 4 was subsequently confirmed using X-ray crystallography. 4 exhibited excellent catalytic performance with regard to 1-decene oligomerization, which was carried out with the intention of preparing lubricant base stocks. High activities (21 × 10(6) g mol(-1) Zr h(-1) activity; TON = 150 000; TOF = 42 s(-1)) were observed at temperatures as high as 120 °C and the oligomer distribution was appropriate for lubricant application. The simulated distillation (SIMDIS) data confirmed that a wide range of oligomers were formed, ranging from the dimer (2-mer) to 20-mer. A minimal amount of the dimer and oligomers larger than the 10-mer was formed (13 and 25 wt%, respectively). Alternatively, a typical unbridged complex such as (η(5)-nBuC5H4)2ZrCl2 primarily produced dimers (54 wt%), whereas the ansa-zirconocene (EBI)ZrCl2 primarily produced oligomers larger than 10-mer (62 wt%). The methyl substituents at the positions adjacent to the bridgehead in 4 played a significant role in the catalytic performance.

16.
Chem Commun (Camb) ; 49(92): 10832-4, 2013 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-24121869

RESUMO

The infiltration of palladium nanoparticles (PdNPs) into the channels of SBA-15 was conveniently achieved via an incipient wetness procedure employing a tetraglyme solution. Electron tomography demonstrated that PdNPs were outgrown preferentially from the channels. The resultant Pd/SBA-15 showed high performance in the dehydrogenation kinetics of ammonia borane.

17.
Chem Commun (Camb) ; 48(14): 2021-3, 2012 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-22234607

RESUMO

Palladium nanoparticles (PdNPs) were conveniently prepared in tetraglyme (TG) solution using a variety of palladium precursors. At 140 °C, TG promoted Pd(3)(OAc)(6) to produce irregular shaped PdNPs with an average size of 4 nm. When these PdNPs were re-dispersed in TG and used for the dehydrogenation of ammonia borane (AB) at 85 °C, remarkably enhanced catalytic performance was achieved to release 2.3 equiv. of H(2) in 1 h.

18.
Korean J Radiol ; 12(5): 595-601, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21927561

RESUMO

OBJECTIVE: To evaluate the usefulness of percutaneous aspiration thromboembolectomy (PAT) via a transbrachial approach in patients with acute upper limb ischemia. MATERIALS AND METHODS: From July 2004 to March 2008, eleven patients with acute upper limb ischemia were enrolled in this study. They were initially treated with thrombolysis (n = 1), PAT (n = 6), or both (n = 4) via a femoral artery approach. However, all of the patients had residual thrombus in the brachial artery, which was subsequently managed by PAT via the transbrachial approach for removal of residual emboli. RESULTS: Successful re-canalization after PAT via a transbrachial approach was achieved in all patients. Two patients experienced early complications: one experienced a massive hematoma of the upper arm due to incomplete compression and was treated by stent deployment. The other patient experienced a re-occlusion of the brachial artery the day after the procedure due to excessive manual compression of the puncture site, but did not show recurrence of ischemic symptoms in the artery of the upper arm. Clinical success with complete resolution of ischemic symptoms was achieved in all patients. CONCLUSION: PAT via a transbrachial approach is a safe and effective treatment for patients with acute upper limb ischemia.


Assuntos
Braço/irrigação sanguínea , Artéria Braquial , Cateterismo Periférico , Embolectomia , Procedimentos Endovasculares , Isquemia/etiologia , Trombectomia , Tromboembolia/terapia , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Fibrilação Atrial/complicações , Artéria Axilar , Embolectomia/métodos , Feminino , Insuficiência Cardíaca/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Trombectomia/métodos , Tromboembolia/etiologia , Terapia Trombolítica
19.
J Am Chem Soc ; 132(29): 9954-5, 2010 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-20597488

RESUMO

Cationic Pd(II) complexes catalyzed the dehydrogenation of ammonia borane in the most efficient manner with the release of 2.0 equiv of H(2) in less than 60 s at 25 degrees C. Most of the hydrogen atoms were obtained from the boron atom of the ammonia borane. The first step of the dehydrogenation reaction was elaborated using density functional theory calculations.

20.
Chemistry ; 16(19): 5630-44, 2010 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-20391583

RESUMO

A series of mono-, bis-, and tris(phenoxy)-titanium(IV) chlorides of the type [Cp*Ti(2-R-PhO)(n)Cl(3-n)] (n=1-3; Cp*=pentamethylcyclopentadienyl) was prepared, in which R=Me, iPr, tBu, and Ph. The formation of each mono-, bis-, and tris(2-alkyl-/arylphenoxy) series was authenticated by structural studies on representative examples of the phenyl series including [Cp*Ti(2-Ph-PhO)Cl(2)] (1 PhCl2), [Cp*Ti(2-Ph-PhO)(2)Cl] (2 PhCl), and [Cp*Ti(2-Ph-PhO)(3)] (3 Ph). The metal-coordination geometry of each compound is best described as pseudotetrahedral with the Cp* ring and the 2-Ph-PhO and chloride ligands occupying three leg positions in a piano-stool geometry. The mean Ti-O distances, observed with an increasing number of 2-Ph-PhO groups, are 1.784(3), 1.802(4), and 1.799(3) A for 1 PhCl2, 2 PhCl, and 3 Ph, respectively. All four alkyl/aryl series with Me, iPr, tBu, and Ph substituents were tested for ethylene homopolymerization after activation with Ph(3)C(+)[B(C(6)F(5))(4)](-) and modified methyaluminoxane (7% aluminum in isopar E; mMAO-7) at 140 degrees C. The phenyl series showed much higher catalytic activity, which ranged from 43.2 and 65.4 kg (mmol of Ti x h)(-1), than the Me, iPr, and tBu series (19.2 and 36.6 kg (mmol of Ti x h)(-1)). Among the phenyl series, the bis(phenoxide) complex of 2 PhCl showed the highest activity of 65.4 kg (mmol of Ti x h)(-1). Therefore, the catalyst precursors of the phenyl series were examined by treating them with a variety of alkylating reagents, such as trimethylaluminum (TMA), triisobutylaluminum (TIBA), and methylaluminoxane (MAO). In all cases, 2 PhCl produced the most catalytically active alkylated species, [Cp*Ti(2-Ph--PhO)MeCl]. This enhancement was further supported by DFT calculations based on the simplified model with TMA.

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