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1.
Heliyon ; 10(9): e29776, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38707271

RESUMO

Acute liver failure is an uncommon presentation in the clinic. Common causes for acute liver failure include viral hepatitis and drug-related hepatotoxicity. However, acute liver failure due to Budd-Chiari syndrome is rare. This case highlights the importance of necessary constrast-enhanced imaging studies to rule out vascular etiologies of acute liver failure, in addition to common causes like viral or drug-induced hepatic failure. We present a case of a male Chinese patient who presented with nausea, vomiting, fatigue, and fever after eating a large amount of fatty food. Six days after hospitalization, the patient developed acute liver failure and hepatic encephalopathy. Contrast-enhanced computerized tomography and ultrasound examinations revealed thromboses in the hepatic veins and inferior vena cava. Further testing also showed decreased protein C activity. Therefore, a diagnosis of Budd-Chiari syndrome secondary to protein C deficiency was made. He received supportive care and a transjugular intrahepatic portal shunt. Hepatic function, coagulation panel results, and clinical presentations gradually returned to normal. Budd-Chiari syndrome from protein C deficiency could be a rare but valid cause of acute liver failure in Chinese patients.

2.
World J Clin Cases ; 12(12): 2074-2078, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38680272

RESUMO

BACKGROUND: This report delves into the diagnostic and therapeutic journey undertaken by a patient with high-dose cantharidin poisoning and multiorgan dysfunction syndrome (MODS). Particular emphasis is placed on the comprehensive elucidation of the clinical manifestations of high-dose cantharidin poisoning, the intricate path to diagnosis, and the exploration of potential underlying mechanisms. CASE SUMMARY: A patient taking 10 g of cantharidin powder orally subsequently developed MODS. The patient was treated with supportive care, fluid hydration and antibiotics, and hemoperfusion and hemofiltration therapy for 24 h and successfully recovered 8 d after hospital admission. Cantharidin poisoning can cause life-threatening MODS and is rare clinically. This case underscores the challenge in diagnosis and highlights the need for early clinical differentiation to facilitate accurate assessment and prompt intervention. CONCLUSION: This article has reported and analyzed the clinical data, diagnosis, treatment, and prognosis of a case of high-dose cantharidin poisoning resulting in MODS and reviewed the relevant literature to improve the clinical understanding of this rare condition.

3.
Biomed Pharmacother ; 173: 116423, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38493593

RESUMO

Corona Virus Disease 2019 (COVID-19) is a global pandemic epidemic caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), which poses a serious threat to human health worldwide and results in significant economic losses. With the continuous emergence of new virus strains, small molecule drugs remain the most effective treatment for COVID-19. The traditional drug development process usually requires several years; however, the development of computer-aided drug design (CADD) offers the opportunity to develop innovative drugs quickly and efficiently. The literature review describes the general process of CADD, the viral proteins that play essential roles in the life cycle of SARS-CoV-2 and can serve as therapeutic targets, and examples of drug screening of viral target proteins by applying CADD methods. Finally, the potential of CADD in COVID-19 therapy, the deficiency, and the possible future development direction are discussed.


Assuntos
COVID-19 , Humanos , SARS-CoV-2 , Descoberta de Drogas , Desenho de Fármacos , Antivirais/farmacologia , Antivirais/uso terapêutico , Antivirais/metabolismo
4.
Toxicon ; 235: 107326, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37871760

RESUMO

Food-borne botulism is a rare but potentially fatal illness. Its management depends on rapid diagnosis and prompt antitoxin administration. However, diagnosing food-borne botulism can be challenging at an early stage. Here, we report a 62-year-old male with food-borne botulism. The patient presented with extremity muscle weakness, dyspnea, bilateral droopy eyelids (more significant on the right side), dysarthria, and progressive dysphagia. The electromyography indicated presynaptic membrane abnormalities. The toxicology screen reported a positive result for botulinum toxin type A. He received plasma exchange, botulism antitoxin, and supportive care. However, he had a cardiac arrest six days later. Spontaneous circulation was restored after immediate cardiopulmonary resuscitation. The patient gradually recovered his muscle strength and could have complete eyelid elevation. A detailed interview revealed that six family members developed similar symptoms. All of them consumed a homemade sauce prepared three years ago. They all tested positive for botulinum toxin type A. Two of them had cardiac arrests. Therefore, family aggregation could happen to botulism. Careful interviews, early diagnosis, and timely administration of botulism antitoxin are the keys to saving lives. Special attentions should be given to the cardiac evaluations since botulism can cause cardiac arrest and death.


Assuntos
Toxinas Botulínicas Tipo A , Botulismo , Parada Cardíaca , Masculino , Humanos , Pessoa de Meia-Idade , Botulismo/diagnóstico , Botulismo/etiologia , Antitoxina Botulínica , Parada Cardíaca/induzido quimicamente , Parada Cardíaca/complicações
5.
Opt Express ; 31(18): 28900-28911, 2023 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-37710699

RESUMO

In this paper, for the first time to the best of our knowledge, we investigate the experiment of polar coded probabilistic shaped 8-ary pulse amplitude modulation (PS-PAM8) in weak turbulence. A systematic interleaver (SIL) is proposed to improve the polar code performance for PS-PAM8, compatible with the 5 G channel coding standard. Considering the effects of turbulence and shaped constellations, the pilot with identical distributions as the transmitted data is used for dynamic channel estimation to avoid demodulation failure. Moreover, the application of hybrid equalization with nonlinear and linear equalizers effectively reduces the receiver sensitivity. In 25 GBd transmission over a 4 m free-space link, the transmission performance of polar coded PAM8 schemes with SIL is better than that of the low-density parity check code by 1.0 dB, and the power budget is further saved by 0.72∼0.83 dB after linear equalization. Meanwhile, the shaping gains of polar coded PS-PAM8 with SIL and hybrid equalization are up to 2.0 dB at 1.5 bits/channel use. In addition, different weak turbulence conditions can be generated inside a chamber, and the observed channel fading is consistent with the log-normal model. The results show that the proposed polar coded PS scheme can improve the Q-factor by 0.49∼1.74 dB in different turbulence conditions.

6.
J Vis ; 23(3): 4, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36892537

RESUMO

By utilizing statistical properties and summary statistics, the visual system can efficiently integrate perception of spatially and temporally adjacent stimuli into perception of a given target. For instance, perception of a target face can either be biased positively toward previous faces (e.g. the serial dependence effect) or be biased negatively by surrounding faces in the same trial/space (e.g. spatial ensemble averaging). However, both aspects were investigated separately. As spatial and temporal processing share the same purpose to reduce redundancy in visual processing, if one statistical processing occurs, would the statistical processing in the other domain still exist or be discarded? We investigated this question by exploring whether serial dependence of face perception (of attractiveness and averageness) survives when the changed face perception in the group context occurs. The results of Markov Chain modeling and conventional methods suggested that serial dependence (the temporal aspect) co-occurs with changed face perception in the group context (the spatial aspect). We also utilized the Hidden Markov modeling, as a new mathematical method, to model statistical processing from both domains. The results confirmed the co-occurrence of temporal effect and changed face perception in the group context for both attractiveness and averageness, suggesting potentially different spatial and temporal compression mechanisms in high-level vision. Further modeling and cluster analysis further revealed that the detailed computation of spatially and temporally adjacent faces in the attractiveness and averageness processing were similar yet different among different individuals. This work builds a bridge to understanding mathematical principles underlying changed face perception in the group context from the serial perspective.


Assuntos
Face , Reconhecimento Facial , Humanos , Beleza , Percepção Visual , Análise por Conglomerados
7.
Complement Ther Clin Pract ; 50: 101675, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36436262

RESUMO

PURPOSE: Exercise training is an efficient non-pharmacological intervention for patients with heart failure (HF). This study aimed to objectively evaluate the effects of Baduanjin exercise on the quality of life (QOL) and exercise capacity in patients with HF. METHODS: PubMed, Embase, the Cochrane Library, Chinese National Knowledge Infrastructure (CNKI), and Wanfang data were searched from the date of their inception until 30 September 2022. All randomised controlled trials (RCTs) evaluating the effects of Baduanjin exercise on QOL and exercise capacity in patients with HF were selected. The primary outcomes were QOL, assessed using the Minnesota Living with Heart Failure Questionnaire (MLHFQ), and exercise capacity, evaluated using the 6-min walking test (6-MWT). A meta-analysis was performed by comparing the MLHFQ domain scores. Review Manager 5.3 and Stata 14.0, were used for the data analysis. RESULTS: Baduanjin exercise showed a favourable improvement of the overall QOL (mean difference = -8.25; 95% confidence interval: -13.62 to -2.89; P = 0.003) and exercise capacity (mean difference = 118.49; 95% confidence interval: 52.57 to 184.41; P = 0.0004). Meta-analyses of the MLHFQ domain score indicated that Baduanjin exercise significantly improved the patients' physical (mean difference = -2.83; 95% confidence interval: -3.76, -1.90; P < 0.00001), emotional (mean difference = -2.52; 95% confidence interval: -3.67 to -1.37; P < 0.0001), and general QOL (mean difference = -2.61; 95% confidence interval: -5.17 to -0.06; P = 0.05), based on the decrease in the MLHFQ domain score. Marked statistical heterogeneity (I2> 70%) was observed for all the QOL and exercise capacity outcomes. CONCLUSIONS: Baduanjin exercise is a safe, feasible, and acceptable intervention that can improve the QOL and exercise capacity in patients with HF. However, more RCTs with rigorous research designs are needed to assist in the rehabilitation of such patients.


Assuntos
Tolerância ao Exercício , Insuficiência Cardíaca , Humanos , Terapia por Exercício , Insuficiência Cardíaca/psicologia , Insuficiência Cardíaca/reabilitação , Qualidade de Vida , Exercício Físico
8.
Front Cardiovasc Med ; 8: 759826, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34926611

RESUMO

Background: Cardiac surgery is associated with a substantial risk of major adverse events. Although carbon dioxide (CO2)-derived variables such as venous-to-arterial CO2 difference (ΔPCO2), and PCO2 gap to arterial-venous O2 content difference ratio (ΔPCO2/C(a-cv)O2) have been successfully used to predict the prognosis of non-cardiac surgery, their prognostic value after cardiopulmonary bypass (CPB) remains controversial. This hospital-based study explored the relationship between ΔPCO2, ΔPCO2/C(a-cv)O2 and organ dysfunction after CPB. Methods: We prospectively enrolled 114 intensive care unit patients after elective cardiac surgery with CPB. Patients were divided into the organ dysfunction group (OI) and non-organ dysfunction group (n-OI) depending on whether organ dysfunction occurred or not at 48 h after CPB. ΔPCO2 was defined as the difference between central venous and arterial CO2 partial pressure. Results: The OI group has 37 (32.5%) patients, 27 of which (23.7%) had one organ dysfunction and 10 (8.8%) had two or more organ dysfunctions. No statistical significance was found (P = 0.84) for ΔPCO2 in the n-OI group at intensive care unit (ICU) admission (9.0, 7.0-11.0 mmHg), and at 4 (9.0, 7.0-11.0 mmHg), 8 (9.0, 7.0-11.0 mmHg), and 12 h post admission (9.0, 7.0-11.0 mmHg). In the OI group, ΔPCO2 also showed the same trend [ICU admission (9.0, 8.0-12.8 mmHg) and 4 (10.0, 7.0-11.0 mmHg), 8 (10.0, 8.5-12.5 mmHg), and 12 h post admission (9.0, 7.3-11.0 mmHg), P = 0.37]. No statistical difference was found for ΔPCO2/C(a-cv)O2 in the n-OI group (P = 0.46) and OI group (P = 0.39). No difference was detected in ΔPCO2, ΔPCO2/C(a-cv)O2 between groups during the first 12 h after admission (P > 0.05). Subgroup analysis of the patients with two or more failing organs compared to the n-OI group showed that the predictive performance of lactate and Base excess (BE) improved, but not of ΔPCO2 and ΔPCO2/C(a-cv)O2. Regression analysis showed that the BE at 8 h after admission (odds ratio = 1.37, 95%CI: 1.08-1.74, P = 0.009) was a risk factor for organ dysfunction 48 h after CBP. Conclusion : ΔPCO2 and ΔPCO2/C(a-cv)O2 cannot be used as reliable indicators to predict the occurrence of organ dysfunction at 48 h after CBP due to the pathophysiological process that occurs after CBP.

10.
Front Med (Lausanne) ; 8: 731593, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34568389

RESUMO

Objective: We investigated whether there were sex differences in adverse reactions to an inactivated SARS-CoV-2 vaccine among medical staff in China. Methods: From 24 February to 7 March 2021 an online cross-sectional survey was conducted with a self-administered COVID-19 vaccine questionnaire among medical staff in Taizhou, China. In total, 1397 interviewees (1,107 women and 290 men) participated in the survey. Results: In our study, 178 (16.1%) women and 23 (7.9%) men reported adverse reactions following their first vaccination, and 169 (15.3%) women and 35 (12.1%) men reported adverse reactions following their second vaccination. After adjusting for confounding factors, adverse reactions to other vaccines, worry about adverse reactions, knowledge of the inactivated vaccine being used in the hospital, taking the vaccine for one's family proactively and receiving an influenza vaccination were significantly related to adverse reactions to both injections in women. In contrast, in men, concerns about adverse reactions independently increased the risk of adverse reactions following either vaccination, and a history of adverse reactions to other vaccines also increased the risk of adverse reactions to both injections. Conclusions: Sex differences in the frequency of reported adverse reactions to an inactivated SARS-CoV-2 vaccine and potential factors were demonstrated in a sample of medical staff.

11.
Cognition ; 212: 104715, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33823426

RESUMO

Cheerleader effects, group attractiveness effects, and divisive normalization are all characterized by faces appearing more attractive when seen within a group. However, it is possible that your friends could have a detrimental effect upon your attractiveness too: if these group effects arose partly as a contrastive process between your face and your friends, then highly attractive friends may diminish your attractiveness. We confirm this hypothesis across two experiments by showing that the presence of highly attractive friends can indeed make you appear less attractive (i.e., a reverse cheerleader effect), suggesting friend effects are driven in part by a contrastive process against the group. However, these effects are also influenced by your own attractiveness in a fashion that appears consistent with hierarchical encoding, where less attractive targets benefit more from being viewed in an increasingly unattractive group than attractive targets. Our final experiment demonstrates that the company of others not only alters our attractiveness, but also induces shifts in how average or distinctive a target face appears too, with these averageness effects associated with the friend effects observed in our first experiment. We present a Friend Effects Framework within which 'friend effects' is an umbrella term for the positive (e.g., cheerleader effects, group attractiveness effects) and negative (i.e., the reverse cheerleader effect) ways in which hierarchical encoding, group contrastive effects, and other influences of friends can have on your attractiveness.


Assuntos
Beleza , Amigos , Face , Humanos
12.
Chem Commun (Camb) ; 56(62): 8846-8849, 2020 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-32633282

RESUMO

A series of chloride-bridged unsymmetrical mixed Fe(ii)-HS/Fe(ii)-LS binuclear structures has been prepared and characterized. Upon activation with MAO, highly efficient catalytic polymerization of isoprene was achieved, delivering an ultra-high molecular weight (catalyst loading = 2.5 ppm, Mn = 1.8 × 106 g mol-1, Mw/Mn = 1.4).

13.
Clin Transl Immunology ; 9(5): e1128, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32399213

RESUMO

OBJECTIVES: Host immune responses are indispensable to combat the disease. We report the dynamics of peripheral immune cells, cytokines, and human leucocyte antigen-G (HLA-G) and its receptor expressions in a patient suffering from critical COVID-19 pneumonia to convalescence. METHODS: Clinical data of the patient were collected from medical records. The expressions of HLA-G and receptors ILT2, ILT4 and KIR2DL4 in peripheral immune cells were measured with flow cytometry. RESULTS: From critical COVID-19 to the convalescent stage, early lymphopenia was improved (median: 0.6 × 109 L-1 vs. 0.9 × 109 L-1, P = 0.009), and an obvious fluctuation in WBC and neutrophil counts was observed. Initially, low levels of CD4+ T cells (from 120 to 528 µL-1) and CD8+ T cells (from 68 to 362 µL-1) gradually increased to normal levels. Meanwhile, high IL-6 (from 251.8 to 6.32 pg mL-1), IL-10 (from 39.53 to 5.21 pg mL-1) and IFN-γ (from 13.55 to 3.16 pg mL-1) levels decreased, and IL-4 (from 2.36 to 3.19 pg mL-1) and TNF-α (from 2.27 to 20.2 pg mL-1) levels increased quickly when the viral RNA returned negative. Moreover, the percentage of HLA-G+ T cells, B cells and monocytes follows high-low-high pattern, while the percentage of receptors ILT2-, ILT4- and KIR2DL4-expressing cells remained relatively stable. CONCLUSION: Our findings provide valuable information on the dynamics of early peripheral immunological responses in SARS-CoV-2 infection. CD4+ and CD8+ T cells, cytokines and HLA-G+ immune cells are associated with the natural history of the critical COVID-19 patient; however, future studies are necessary.

14.
Environ Sci Technol ; 49(12): 7356-63, 2015 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-26018772

RESUMO

Composting is widely used for recycling of urban sewage sludge to improve soil properties, which represents a potential pathway of spreading antibiotic resistant bacteria and genes to soils. However, the dynamics of antibiotic resistance genes (ARGs) and the underlying mechanisms during sewage sludge composting were not fully explored. Here, we used high-throughput quantitative PCR and 16S rRNA gene based illumina sequencing to investigate the dynamics of ARGs and bacterial communities during a lab-scale in-vessel composting of sewage sludge. A total of 156 unique ARGs and mobile genetic elements (MGEs) were detected encoding resistance to almost all major classes of antibiotics. ARGs were detected with significantly increased abundance and diversity, and distinct patterns, and were enriched during composting. Marked shifts in bacterial community structures and compositions were observed during composting, with Actinobacteria being the dominant phylum at the late phase of composting. The large proportion of Actinobacteria may partially explain the increase of ARGs during composting. ARGs patterns were significantly correlated with bacterial community structures, suggesting that the dynamic of ARGs was strongly affected by bacterial phylogenetic compositions during composting. These results imply that direct application of sewage sludge compost on field may lead to the spread of abundant ARGs in soils.


Assuntos
Bactérias/genética , Resistência Microbiana a Medicamentos/genética , Esgotos/microbiologia , Solo , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Elementos de DNA Transponíveis/genética , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Dosagem de Genes , Genes Bacterianos , Variação Genética , Concentração de Íons de Hidrogênio , Análise de Componente Principal , RNA Ribossômico 16S/genética
15.
J Med Chem ; 55(5): 2089-101, 2012 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-22247956

RESUMO

Starting from indole-based C-3 pyridone HCV NS5B polymerase inhibitor 2, structure-activity relationship (SAR) investigations of the indole N-1 benzyl moiety were performed. This study led to the discovery of irreversible inhibitors with p-fluoro-sulfone- or p-fluoro-nitro-substituted N-1 benzyl groups which achieved breakthrough replicon assay potency (EC(50) = 1 nM). The formation of a covalent bond with adjacent cysteine-366 thiol was was proved by mass spectroscopy and X-ray crystal structure studies. The C-5 ethyl C-2 carboxylic acid derivative 47 had an excellent oral area-under-the-curve (AUC) of 18 µM·h (10 mg/kg). Its oral exposure in monkeys and dogs was also very good. The NMR ALARM assay, mass spectroscopy experiments, in vitro counter screening, and toxicology assays demonstrated that the covalent bond formation between compound 47 and the protein was highly selective and specific. The overall excellent profile of 47 made it an interesting candidate for further investigation.


Assuntos
Antivirais/síntese química , Hepacivirus/efeitos dos fármacos , Indóis/síntese química , Nitrocompostos/síntese química , Sulfonas/síntese química , Proteínas não Estruturais Virais/antagonistas & inibidores , Animais , Antivirais/farmacocinética , Antivirais/farmacologia , Cristalografia por Raios X , Cães , Haplorrinos , Hepacivirus/enzimologia , Indóis/farmacocinética , Indóis/farmacologia , Modelos Moleculares , Estrutura Molecular , Testes de Mutagenicidade , Nitrocompostos/farmacocinética , Nitrocompostos/farmacologia , Piridonas/síntese química , Piridonas/farmacocinética , Piridonas/farmacologia , Ratos , Relação Estrutura-Atividade , Sulfonas/farmacocinética , Sulfonas/farmacologia
16.
J Med Chem ; 55(2): 754-65, 2012 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-22148957

RESUMO

Starting with the indole-based C-3 pyridone lead HCV polymerase inhibitor 2, extensive SAR studies were performed at different positions of the indole core. The best C-5 groups were found to be compact and nonpolar moieties and that the C-6 attachments were not affecting potency. Limited N-1 benzyl-type substituent studies indicated that the best substitutions were fluoro or methyl groups at 2' or 5' positions of the benzyl group. To improve pharmacokinetic (PK) properties, acylsulfonamides were incorporated as acid isosteres at the C-2 position. Further optimization of the combination at N-1, C-2, C-5, and C-6 resulted in the identification of compound 56, which had an excellent potency in both NS5B enzyme (IC(50) = 0.008 µM) and cell-based replicon (EC(50) = 0.02 µM) assays and a good oral PK profile with area-under-the curve (AUC) of 14 and 8 µM·h in rats and dogs, respectively. X-ray structure of inhibitor 56 bound to the enzyme was also reported.


Assuntos
Antivirais/síntese química , Hepacivirus/enzimologia , Indóis/síntese química , Sulfonamidas/síntese química , Proteínas não Estruturais Virais/antagonistas & inibidores , Administração Oral , Animais , Antivirais/farmacocinética , Antivirais/farmacologia , Células CACO-2 , Cristalografia por Raios X , Cães , Hepacivirus/efeitos dos fármacos , Hepacivirus/genética , Humanos , Indóis/química , Indóis/farmacocinética , Indóis/farmacologia , Modelos Moleculares , Estrutura Molecular , Permeabilidade , Ratos , Replicon , Relação Estrutura-Atividade , Sulfonamidas/farmacocinética , Sulfonamidas/farmacologia
17.
J Chromatogr A ; 1218(24): 3816-21, 2011 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-21565348

RESUMO

The paper presents an on-line transient moving chemical reaction boundary (MCRB) method for simply but efficiently stacking analytes in capillary electrophoresis (CE). The CE technique was developed for a rapid determination of fumaric and maleic acid. Based on the theory of MCRB, Effects of several important factors such as the pH and concentration of running buffer and the conditions of stacking analytes were investigated to acquire the optimum conditions. The optimized separations were carried out in a 20 mmol/L sulphate neutralized with ethylenediamine to pH 6.0 electrolytes using a capillary coated with poly (diallyldimethylammonium chloride) and direct UV detection at 214 nm. The optimized preconcentrations were carried out in 50 mmol/L borax (pH 9.0). The calibration curves were linear in the concentration range of 1.0×10⁻7-1.0×10⁻4 mol/L and 5.0×10⁻7-1.0×10⁻4 mol/L for fumaric and maleic acid with correlation coefficients higher than 0.9991. The detection limits were 5.34×10⁻8 mol/L for fumaric acid and 1.92×10⁻7 mol/L for maleic acid. This method was applied for determination of fumaric acid in apple juice and of fumaric and maleic acid in dl-malic, the recovery tests established for real samples were within the range 95-105%. This work provided a valid and simple approach to detect fumaric and maleic acid.


Assuntos
Eletroforese Capilar/métodos , Fumaratos/análise , Maleatos/análise , Álcalis/química , Boratos/química , Etilenodiaminas/química , Fumaratos/isolamento & purificação , Concentração de Íons de Hidrogênio , Modelos Lineares , Maleatos/isolamento & purificação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Ácidos Sulfúricos/química
18.
Nanoscale ; 3(3): 916-8, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21132171

RESUMO

Highly dispersed Ag nanoparticles, stabilized by hyperbranched copolymers (HPCs), were prepared by chemical reduction in toluene. These Ag NPs were used further for the fabrication of a hydrogen peroxide (H2O2) sensor, by which a good catalytic ability for the reduction of H2O2 was found.


Assuntos
Condutometria/instrumentação , Peróxido de Hidrogênio/análise , Peróxido de Hidrogênio/química , Nanoestruturas/química , Prata/química , Transdutores , Catálise , Cristalização/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Substâncias Macromoleculares/química , Teste de Materiais , Conformação Molecular , Nanoestruturas/ultraestrutura , Nanotecnologia/métodos , Oxirredução , Tamanho da Partícula , Polímeros/química , Propriedades de Superfície
19.
ACS Med Chem Lett ; 1(2): 64-9, 2010 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-24900178

RESUMO

Boceprevir (SCH 503034), 1, a novel HCV NS3 serine protease inhibitor discovered in our laboratories, is currently undergoing phase III clinical trials. Detailed investigations toward a second generation protease inhibitor culminated in the discovery of narlaprevir (SCH 900518), 37, with improved potency (∼10-fold over 1), pharmacokinetic profile and physicochemical characteristics, currently in phase II human trials. Exploration of synthetic sequence for preparation of 37 resulted in a route that required no silica gel purification for the entire synthesis.

20.
Talanta ; 79(3): 780-6, 2009 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-19576445

RESUMO

Magnetic nanoparticles (Fe(3)O(4)) were synthesized by a chemical coprecipitation method. X-ray diffraction (XRD) and transmission electron microscope (TEM) were used to confirm the crystallite structure and the particle's radius. The Fe(3)O(4) nanoparticles and chitosan (CS) were mixed to form a matrix in which haemoglobin (Hb) can be immobilized for the fabrication of H(2)O(2) biosensor. The Fe(3)O(4)-CS-Hb film exhibited a pair of well-defined and quasi-reversible cyclic voltammetric peaks due to the redox of Hb-heme Fe (III)/Fe (II) in a pH 7.0 phosphate buffer. The formal potential of Hb-heme Fe(III)/Fe(II) couple varied linearly with the increase of pH in the range of 4.0-10.0 with a slope of 46.5 mV pH(-1), indicating that electron transfer was accompanied with single proton transportation in the electrochemical reaction. The surface coverage of Hb immobilized on Fe(3)O(4)-CS film glassy carbon electrode was about 1.13 x 10(-10)mol cm(-2). The heterogeneous electron transfer rate constant (k(s)) was 1.04 s(-1), indicating great facilitation of the electron transfer between Hb and magnetic nanoparticles-chitosan modified electrode. The modified electrode showed excellent electrocatalytic activity toward oxygen and hydrogen peroxide reduction. The apparent Michaelis-Menten constant K(M)(app) for H(2)O(2) was estimated to be 38.1 micromol L(-1).


Assuntos
Quitosana/química , Hemoglobinas/química , Proteínas Imobilizadas/química , Magnetismo , Nanopartículas/química , Animais , Técnicas Biossensoriais , Catálise , Bovinos , Eletroquímica , Eletrodos , Transporte de Elétrons , Óxido Ferroso-Férrico/química , Hemoglobinas/metabolismo , Peróxido de Hidrogênio/análise , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Proteínas Imobilizadas/metabolismo , Oxigênio/química , Estrutura Secundária de Proteína , Reprodutibilidade dos Testes , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier
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