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1.
J Clin Monit Comput ; 36(3): 649-655, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-33783692

RESUMO

High-flow nasal oxygen (HFNO) has been used in "tubeless" shared-airway surgeries but whether HFNO increased the fire hazard is yet to be examined. We used a physical model for simulation to explore fire safety through a series of ignition trials. An HFNO device was attached to a 3D-printed nose with nostrils connected to a degutted raw chicken. The HFNO device was set at twenty combinations of different oxygen concentration and gas flow rate. An electrocautery and diode laser were applied separately to a fat cube in the cavity of the chicken. Ten 30 s trials of continuous energy source application were conducted. An additional trial of continuous energy application was conducted if no ignition was observed for all the ten trials. A total of eight short flashes were observed in one hundred electrocautery tests; however, no continuous fire was observed among them. There were thirty-six events of ignition in one hundred trials with laser, twelve of which turned into violent self-sustained fires. The factors found to be related to a significantly increased chance of ignition included laser application, lower gas flow, and higher FiO2. The native tissue and smoke can ignite and turn into violent self-sustained fires under HFNO and continuous laser strikes, even in the absence of combustible materials. The results suggest that airway surgeries must be performed safely with HFNO if only a short intermittent laser is used in low FiO2.


Assuntos
Diatermia , Incêndios , Eletrocoagulação , Humanos , Lasers , Oxigênio
2.
Sci Rep ; 11(1): 18466, 2021 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-34531482

RESUMO

An isolated bacterium TBE-8, was identified as Leuconostoc mesenteroides according to the sequences of 16S rDNA and the 16S-23S rDNA intergenic spacer region. The probiotic properties of the L. mesenteroides TBE-8 strain were characterized and revealed that TBE-8 could utilize various carbohydrates, exhibited high tolerance to sucrose's osmotic pressure and acidic conditions, and could mitigate the impact of the bee pathogen Paenibacillus larvae. In addition, we found that the TBE-8 broth increased the expression of the nutrition-related genes major royal jelly protein 1 and vitellogenin in bees by approximately 1400- and 20-fold, respectively. The expression of genes encoding two antibacterial peptides, hymenoptaecin and apidaecin, in the bee abdomen was significantly increased by 17- and 7-fold in bees fed with the TBE-8 fermented broth. Furthermore, we fed four-frame bee colonies with 50% sucrose syrup containing TBE-8 and can detect the presence of approximately 2 × 106 16S rDNA copies of TBE-8 in the guts of all bees in 24 h, and the retention of TBE-8 in the bee gut for at least 5 days. These findings indicate that the L. mesenteroides TBE-8 has high potential as a bee probiotic and could enhance the health of bee colonies.


Assuntos
Abelhas/microbiologia , Resistência à Doença , Leuconostoc mesenteroides/patogenicidade , Probióticos , Animais , Peptídeos Catiônicos Antimicrobianos/genética , Peptídeos Catiônicos Antimicrobianos/metabolismo , Abelhas/metabolismo , Metabolismo dos Carboidratos , Glicoproteínas/genética , Glicoproteínas/metabolismo , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Leuconostoc mesenteroides/genética , Paenibacillus larvae/patogenicidade , RNA Ribossômico 16S/genética , Vitelogeninas/genética , Vitelogeninas/metabolismo
3.
Acta Cardiol Sin ; 36(5): 483-492, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32952358

RESUMO

BACKGROUND: Hyperuricemia (HUA) induces inflammation and insulin resistance and is reportedly associated with left ventricular hypertrophy (LVH) and possibly with left ventricular diastolic dysfunction (LVDD). OBJECTIVES: To investigate associations among HUA, inflammation, and insulin resistance with LVDD. METHODS: We enrolled patients with metabolic syndrome (MetS) between August 1, 2017, and December 31, 2017. All participants underwent fasting blood tests and transthoracic echocardiography. HUA was defined as an serum uric acid level ≥ 7 mg/dl in men or ≥ 6 mg/dl in women. MetS was defined as at least three of the following Taiwanese criteria: central obesity, prehypertension, fasting glucose impairment, hypertriglyceridemia, and lower values of high-density lipoprotein cholesterol. LVDD was defined according to contemporary guidelines. RESULTS: The study included 63 patients (60% male) with a mean age of 53 ± 14 years and body mass index (BMI) of 29.4 ± 4.0 kg/m2. Prevalence rates of HUA, LVH, LVDD were 40%, 18%, and 10%, respectively. Baseline characteristics were similar between the HUA and normouricemia groups, except that the HUA group had significantly higher serum high-sensitivity interleukin 6 and tumor necrosis factor-alpha (TNF-α) levels. LVDD occurred more frequently in the HUA group (20.0% vs. 2.6%, p = 0.032). HUA was associated with LVDD [crude odds ratio (OR): 9.25, 95% confidence interval (CI): 1.01-84.7, p = 0.049]. In multivariate analysis, the most relevant factor associated with LVDD was TNF-α after adjustments for age, male sex, and body mass index (adjusted OR for TNF-α: 4.1, 95% CI: 1.02-16.5, p = 0.047). CONCLUSIONS: The association between HUA and LVDD partially reflected a low-grade inflammation due to elevated TNF-α rather than increased insulin resistance in MetS patients.

4.
BMJ Case Rep ; 12(12)2019 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-31892627

RESUMO

We present the case of infected wet gangrene of right foot in the setting of poorly controlled type 2 diabetes in a 71-year-old woman. This patient presented with improved infection condition after intravenous piperacillin-tazobactam (PTZ) 2.25 gm every 6 hours treatment and below knee amputation surgery on day 3. However, neutropenia and thrombocytopenia developed on day 13. We consulted a haematologist and performed a series of examinations. However, no significant findings were noted thereafter. PTZ was suspected to be the most likely cause of neutropenia and thrombocytopenia and was hence terminated on day 14 (cumulative dose of PTZ: 126 g) following stabilisation of the infection condition. A transfusion was performed with two units of single donor platelets on day 14 and treated with intravenous dexamethasone 5 mg every 8 hours from day 14 to 16. Her white blood cell and platelet counts increased on day 15 and continued to recover thereafter.


Assuntos
Diabetes Mellitus Tipo 2 , Pé Diabético/tratamento farmacológico , Neutropenia/diagnóstico , Trombocitopenia/diagnóstico , Idoso , Antibacterianos/efeitos adversos , Diagnóstico Diferencial , Feminino , Humanos , Neutropenia/induzido quimicamente , Neutropenia/complicações , Combinação Piperacilina e Tazobactam/efeitos adversos , Trombocitopenia/induzido quimicamente , Trombocitopenia/complicações
5.
Sci Rep ; 7(1): 5341, 2017 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-28706224

RESUMO

Genetic variation evolves during postglacial range expansion of a species and is important for adapting to varied environmental conditions. It is crucial for the future survival of a species. We investigate the nuclear DNA sequence variation to provide evidence of postglacial range expansion of Musa basjoo var. formosana, a wild banana species, and test for adaptive evolution of amplified fragment length polymorphic (AFLP) loci underlying local adaptation in association with environmental variables. Postglacial range expansion was suggested by phylogeographical analyses based on sequence variation of the second intron of copper zinc superoxide dismutase 2 gene. Two glacial refugia were inferred by the average F ST parameter (mean F ST of a population against the remaining populations). Using variation partitioning by redundancy analysis, we found a significant amount of explained AFLP variation attributed to environmental and spatially-structured environmental effects. By combining genome scan methods and multiple univariate logistic regression, four AFLP loci were found to be strongly associated with environmental variables, including temperature, precipitation, soil moisture, wet days, and surface coverage activity representing vegetation greenness. These environmental variables may have played various roles as ecological drivers for adaptive evolution of M. basjoo var. formosana during range expansion after the last glacial maximum.


Assuntos
Ecossistema , Musa/crescimento & desenvolvimento , Dispersão Vegetal , Adaptação Biológica , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Clima , DNA de Plantas/genética , Variação Genética , Genética Populacional , Musa/classificação , Musa/genética , Filogeografia
6.
J Diabetes Investig ; 7(2): 190-6, 2016 03.
Artigo em Inglês | MEDLINE | ID: mdl-27042270

RESUMO

AIMS/INTRODUCTION: Studies suggest that salivary proteins can be used as potential non-invasive markers for clinical diagnosis and screening for diabetes. Previous reports showed that plasma alpha 2-macroglobulin (A2MG) levels were higher in diabetic patients, especially with diabetic complications. We investigated the relationship between salivary A2MG values and clinical characteristics in patients with type 2 diabetes. MATERIALS AND METHODS: A total of 91 adults were recruited from our outpatient clinics. The study the patients' collected general and biochemical data, and blood glucose (fasting glucose, glycated hemoglobin [HbA1c]) data. Plasma and salivary A2MG levels were examined by enzyme-linked immunosorbent assay. RESULTS: The salivary A2MG levels were significantly positively correlated with plasma A2MG levels, fasting glucose HbA1c and periodontitis status. After 3 months of follow up, the net change of salivary A2MG values positively correlated with the net change of fasting glucose, HbA1c and triglyceride levels, but negatively correlated with high-density lipoprotein cholesterol changes. Furthermore, the correlations between salivary A2MG and fasting glucose HbA1c were better than plasma A2MG, respectively. CONCLUSIONS: Our data show that salivary A2MG levels have better correlation with fasting glucose HbA1c and periodontitis status than plasma A2MG in diabetic patients. Salivary A2MG concentration might serve as a non-invasive marker for clinical diabetic control.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Saliva/metabolismo , alfa-Macroglobulinas/metabolismo , Biomarcadores/sangue , Biomarcadores/metabolismo , Glicemia , Diabetes Mellitus Tipo 2/diagnóstico , Hemoglobinas Glicadas/metabolismo , Humanos
7.
Endocrine ; 49(3): 703-10, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25666934

RESUMO

Recent studies have demonstrated that the plasma soluble receptor for advanced glycation end-products (sRAGE) play a major role in developing macrovascular complications of type 2 diabetes, including peripheral arterial occlusion disease (PAOD). Cilostazol is an antiplatelet, antithrombotic agent, which has been used for the treatment of PAOD. We hypothesized that cilostazol attenuates the severity of PAOD in patients with type 2 diabetes through the augmentation of plasma sRAGE. Ninety type 2 diabetic patients with PAOD defined as intermittent claudication with ankle-brachial index (ABI) ≦0.9 were recruited for an open-labeled, placebo-controlled study for 52 weeks with oral cilostazol 100 mg twice daily (n = 45) or placebo (n = 45). Fasting plasma sRAGE, endothelial variables of E-selectin, soluble vascular cell adhesion molecule-1 (sVCAM-1), and inflammatory markers of high-sensitivity C-reactive protein (hsCRP) and tumor necrosis factor-α (TNF-α) were determined. After completely the 52-week treatment program, the ABI values were elevated in cilostazol group (P < 0.001). The plasma sRAGE was significantly increased (P = 0.007), and hsCRP, sVCAM, and E-selectin concentrations were significantly decreased (P = 0.028, <0.001 and <0.001, respectively) with cilostazol treatment. In a partial correlation analysis with adjustments for sex and age, the net change of sRAGE significantly correlated with the change of ABI in the cilostazol group (P = 0.043). In a stepwise multiple regression model, only the change with regards to sRAGE was significantly associated with the change of ABI (P = 0.046). Our results suggest that cilostazol may effectively attenuate the severity of PAOD in patients with type 2 diabetes. Plasma sRAGE plays a role as an independent predictor for improving the index of PAOD.


Assuntos
Arteriopatias Oclusivas/tratamento farmacológico , Arteriopatias Oclusivas/etiologia , Diabetes Mellitus Tipo 2/complicações , Fibrinolíticos/uso terapêutico , Receptor para Produtos Finais de Glicação Avançada/sangue , Tetrazóis/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Índice Tornozelo-Braço , Proteína C-Reativa/análise , Cilostazol , Selectina E/sangue , Feminino , Humanos , Claudicação Intermitente/etiologia , Claudicação Intermitente/fisiopatologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Receptor para Produtos Finais de Glicação Avançada/genética , Molécula 1 de Adesão de Célula Vascular/sangue
8.
J Med Case Rep ; 8: 304, 2014 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-25213589

RESUMO

INTRODUCTION: Glucagon-like peptide-1 receptor agonists, a new class of anti-diabetic drugs, are widely used in the treatment of type 2 diabetes. However, the effect of glucagon-like peptide-1 receptor agonists on the treatment of preoperative weight loss in obese type 2 diabetic patients has not been reported. CASE PRESENTATION: A 38-year-old Taiwanese woman presented to our hospital with morbid obesity and type 2 diabetes mellitus. Bariatric surgery was recommended by a general surgery specialist. Weight loss before surgery was recommended to reduce the frequency of surgical complications. In addition to diet control with lifestyle modifications, pharmacological treatment with metformin and glucagon-like peptide-1 receptor agonists was administered. Fourteen months of treatment reduced her hemoglobin A1c level from 7.4 to 5.5% and reduced her body weight by 21.2 kg. CONCLUSIONS: One year of diet control with lifestyle modifications and pharmacological treatment with glucagon-like peptide-1 receptor agonists and metformin markedly decreased hemoglobin A1c levels and resulted in effective and substantial weight loss in a morbidly obese patient with dysregulated diabetes during the preoperative period.


Assuntos
Cirurgia Bariátrica , Diabetes Mellitus Tipo 2/complicações , Hipoglicemiantes/uso terapêutico , Obesidade Mórbida/tratamento farmacológico , Peptídeos/uso terapêutico , Cuidados Pré-Operatórios/métodos , Receptores de Glucagon/agonistas , Peçonhas/uso terapêutico , Adulto , Terapia Combinada , Diabetes Mellitus Tipo 2/tratamento farmacológico , Exenatida , Feminino , Receptor do Peptídeo Semelhante ao Glucagon 1 , Humanos , Metformina/uso terapêutico , Obesidade Mórbida/complicações , Obesidade Mórbida/cirurgia , Redução de Peso
9.
Plant Physiol ; 158(1): 340-51, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22095046

RESUMO

Although glutathione S-transferases (GSTs) are thought to play major roles in oxidative stress metabolism, little is known about the regulatory functions of GSTs. We have reported that Arabidopsis (Arabidopsis thaliana) GLUTATHIONE S-TRANSFERASE U17 (AtGSTU17; At1g10370) participates in light signaling and might modulate various aspects of development by affecting glutathione (GSH) pools via a coordinated regulation with phytochrome A. Here, we provide further evidence to support a negative role of AtGSTU17 in drought and salt stress tolerance. When AtGSTU17 was mutated, plants were more tolerant to drought and salt stresses compared with wild-type plants. In addition, atgstu17 accumulated higher levels of GSH and abscisic acid (ABA) and exhibited hyposensitivity to ABA during seed germination, smaller stomatal apertures, a lower transpiration rate, better development of primary and lateral root systems, and longer vegetative growth. To explore how atgstu17 accumulated higher ABA content, we grew wild-type plants in the solution containing GSH and found that they accumulated ABA to a higher extent than plants grown in the absence of GSH, and they also exhibited the atgstu17 phenotypes. Wild-type plants treated with GSH also demonstrated more tolerance to drought and salt stresses. Furthermore, the effect of GSH on root patterning and drought tolerance was confirmed by growing the atgstu17 in solution containing l-buthionine-(S,R)-sulfoximine, a specific inhibitor of GSH biosynthesis. In conclusion, the atgstu17 phenotype can be explained by the combined effect of GSH and ABA. We propose a role of AtGSTU17 in adaptive responses to drought and salt stresses by functioning as a negative component of stress-mediated signal transduction pathways.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/genética , Arabidopsis/fisiologia , Secas , Glutationa Transferase/genética , Glutationa/metabolismo , Tolerância ao Sal , Ácido Abscísico/farmacologia , Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/metabolismo , Butionina Sulfoximina/farmacologia , Técnicas de Inativação de Genes , Germinação/efeitos dos fármacos , Glutationa/farmacologia , Glutationa Transferase/metabolismo , Mutação , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Estômatos de Plantas/efeitos dos fármacos , Transdução de Sinais
10.
Plant Physiol ; 158(1): 363-75, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22095047

RESUMO

Transcriptional activities of plants play important roles in responses to environmental stresses. ETHYLENE RESPONSE FACTOR53 (AtERF53) is a drought-induced transcription factor that belongs to the AP2/ERF superfamily and has a highly conserved AP2 domain. It can regulate drought-responsive gene expression by binding to the GCC box and/or the dehydration-responsive element in the promoter of downstream genes. Overexpression of AtERF53 driven by the cauliflower mosaic virus 35S promoter resulted in an unstable drought-tolerant phenotype in T2 transgenic Arabidopsis (Arabidopsis thaliana) plants. Using a yeast two-hybrid screen, we identified a RING domain ubiquitin E3 ligase, RGLG2, which interacts with AtERF53 in the nucleus. The copine domain of RGLG2 exhibited the strongest interacting activity. We also demonstrated that RGLG2 could move from the plasma membrane to the nucleus under stress treatment. Using an in vitro ubiquitination assay, RGLG2 and its closest sequelog, RGLG1, were shown to have E3 ligase activity and mediated AtERF53 ubiquitination for proteasome degradation. The rglg1rglg2 double mutant but not the rglg2 or rglg1 single mutant exhibited a drought-tolerant phenotype when compared with wild-type plants. AtERF53-green fluorescent proteins expressed in the rglg1rglg2 double mutants were stable. The 35S:AtERF53-green fluorescent protein/rglg1rglg2 showed enhanced AtERF53-regulated gene expression and had greater tolerance to drought stress than the rglg1rglg2 double mutant. In conclusion, RGLG2 negatively regulates the drought stress response by mediating AtERF53 transcriptional activity in Arabidopsis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Fatores de Transcrição/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteínas de Arabidopsis/genética , Membrana Celular/metabolismo , Núcleo Celular/genética , Núcleo Celular/metabolismo , Secas , Regulação da Expressão Gênica de Plantas , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Mutação , Plantas Geneticamente Modificadas/fisiologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Estrutura Terciária de Proteína , Tolerância ao Sal , Estresse Fisiológico , Fatores de Transcrição/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitinação
11.
Curr Diabetes Rev ; 7(5): 305-12, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21682693

RESUMO

CONTEXT: Owing to the pathogenic role of insulin resistance and beta-cell dysfunction in type 2 diabetes, the clinical manifestation of this disease is extremely complex and is often associated with obesity. In recent years, Roux-en-Y gastric bypass (RYGB) surgery, which was originally developed to treat morbid obesity, has been found to have therapeutic potential for diabetes. However, the underlying mechanisms of the therapeutic application of this technique are not fully known. OBJECTIVE: This review describes the technique of RYGB, including the advantages and disadvantages of the procedure. The advantages include metabolic improvement, obesity resolution, and reduction in morbidity. The disadvantages include short-term perioperative complications and long-term nutritional disorders. Finally, we provide a review of the possible underlying mechanisms leading to the resolution of type 2 diabetes symptoms after the RYGB procedure. CONCLUSIONS: While some complications are found after RYGB, there have also been reports showing a remarkable decrease in mortality, successful weight loss, and resolution of type 2 diabetes. The actual mechanism leading to diabetes resolution remains unknown. Gastric bypass surgery is certainly an effective method to increase remission rate in a subgroup of type 2 diabetes patients with morbid obesity.


Assuntos
Diabetes Mellitus Tipo 2/cirurgia , Derivação Gástrica , Obesidade Mórbida/cirurgia , Diabetes Mellitus Tipo 2/etiologia , Diabetes Mellitus Tipo 2/metabolismo , Derivação Gástrica/efeitos adversos , Derivação Gástrica/métodos , Humanos , Resistência à Insulina , Obesidade Mórbida/complicações , Obesidade Mórbida/metabolismo , Resultado do Tratamento , Redução de Peso
12.
Rev Sci Instrum ; 80(11): 115105, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19947755

RESUMO

This paper presents a real-time straightness measurement and compensation system with an optical straightness measurement system and a single-axis flexure-hinge type lead zirconate titanate (PZT)-based compensation stage. The optical straightness measurement system consists of a He-Ne laser, a quadrant photodiode detector, and five right-angle reflectors. Multiple laser beam reflections between the right-angle reflectors increase the sensitivity of the straightness measurement by a factor of 6. The right-angle reflectors can be moved by the flexure-hinge type PZT-based compensation stage that is actuated by a PZT actuator to ensure that the laser beam is always projected onto the center of the quadrant detector. These two systems are integrated and fixed on a scanning stage. The resolution of the straightness measurement system is 0.1 microm. Using the real-time straightness compensation system, the straightness error of the scanning stage is fed back to the control system. The compensated straightness error of the scanning stage system was reduced from 6.5 microm to less than 1 microm.

13.
J Biomol NMR ; 38(1): 57-63, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17333485

RESUMO

Chemical shifts of amino acids in proteins are the most sensitive and easily obtainable NMR parameters that reflect the primary, secondary, and tertiary structures of the protein. In recent years, chemical shifts have been used to identify secondary structure in peptides and proteins, and it has been confirmed that (1)H(alpha), (13)C(alpha), (13)C(beta), and (13)C' NMR chemical shifts for all 20 amino acids are sensitive to their secondary structure. Currently, most of the methods are purely based on one-dimensional statistical analyses of various chemical shifts for each residue to identify protein secondary structure. However, it is possible to achieve an increased accuracy from the two-dimensional analyses of these chemical shifts. The 2DCSi approach performs two-dimension cluster analyses of (1)H(alpha), (1)H(N), (13)C(alpha), (13)C(beta), (13)C', and (15)N(H) chemical shifts to identify protein secondary structure and the redox state of cysteine residue. For the analysis of paired chemical shifts of 6 data sets, each of the 20 amino acids has its own 15 two-dimension cluster scattering diagrams. Accordingly, the probabilities for identifying helix and extended structure were calculated by using our scoring matrix. Compared with existing the chemical shift-based methods, it appears to improve the prediction accuracy of secondary structure identification, particularly in the extended structure. In addition, the probability of the given residue to be helix or extended structure is displayed, allows the users to make decisions by themselves.


Assuntos
Análise por Conglomerados , Espectroscopia de Ressonância Magnética/métodos , Proteínas/química , Estrutura Secundária de Proteína
14.
J Colloid Interface Sci ; 308(1): 81-92, 2007 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-17250847

RESUMO

Nano-sized TiO(2) or SiO(2)/TiO(2) particles were prepared by hydrolysis and condensation reactions in aqueous media, followed by mixing with poly(AA-co-MMA) latex to form different composites, then blending with poly(ethylene terephthalate), PET. The TGA results of composites indicated that negative charged latexes had greater interaction with TiO(2)/ or SiO(2)/TiO(2) particles through strong electrostatic forces, while cationic latexes incorporated with TiO(2) or SiO(2)/TiO(2) particles by pH induced coagulation, carbonyl group chelation and hydrogen bonding. The soapless latex polymer particles showed lower ability of adsorption to TiO(2) particles due to the decrease of total surface area of these larger particles. If SiO(2)/TiO(2) particles were used instead of TiO(2) particles, unexpected high adsorption result was observed. Morphology results observed by SEM showed that PET blended with positive charged composites was more homogeneous than PET blended with negative charged composites. DSC results also indicated that the T(g) of PET was increased, melting temperatures (T(m) or T(m)(')) were increased, and the temperature range of crystallization was narrowed after blending with the composites. The presence of composites affected the mobility and packing of PET molecular chains therefore changing the thermal properties of PET.

15.
Proteins ; 63(1): 219-26, 2006 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-16444707

RESUMO

We report 2D cluster analyses of 1Halpha, 1HN, 13Calpha, and 13C' versus 13Cbeta NMR chemical shifts (CSs) that can be used to predict the redox state and secondary structure of cysteine residues in proteins. A database of cysteine 1Halpha, 1Hbeta2, 1Hbeta3, 1HN, 13Calpha, 13Cbeta, 13C', and 15NH CSs as a function of secondary structure and redox state was constructed from BioMagResBank entries. One-dimensional statistical analysis showed that cysteine 1Halpha, 1HN, 13Calpha, 13C', and 15NH CSs reflected the secondary structure, and that cysteine Cbeta CS is extremely sensitive to the redox state. In contrast, cysteine 1Hbeta CS was not correlated with its redox state or secondary structure. Two-dimensional cluster analysis revealed that 2D Calpha/Cbeta, C'/Cbeta, HNu/Cbeta, and Halpha/Cbeta clusters were helpful in distinguishing both the redox state and secondary structure of cysteine residues. Based on these results, we derived rules using a score matrix to predict the redox state and secondary structure of cysteines using their CSs. The score matrix predicts the redox state and secondary structure of cysteine residues in proteins with approximately 90% accuracy. This suggests that the redox state and secondary structure of cysteine residues in peptides and proteins can be obtained from their CSs without recourse to nuclear Overhauser effect measurements.


Assuntos
Cisteína/química , Bases de Dados de Proteínas , Espectroscopia de Ressonância Magnética/métodos , Oxirredução , Proteômica/métodos , Algoritmos , Animais , Isótopos de Carbono , Análise por Conglomerados , Biologia Computacional/métodos , Humanos , Modelos Estatísticos , Isótopos de Nitrogênio , Ressonância Magnética Nuclear Biomolecular , Peptídeos/química , Conformação Proteica , Estrutura Secundária de Proteína
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