Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 48
Filtrar
Mais filtros

País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Infect Dis ; 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38864524

RESUMO

BACKGROUND: The in vitro cultivation of human noroviruses allows a comparison of antibody levels measured in neutralization and histoblood group antigen (HBGA)-blocking assays. METHODS: Serum samples collected during the evaluation of an investigational norovirus vaccine (HIL-214 [formerly TAK-214]) were assayed for neutralizing antibody levels against the vaccine's prototype Norwalk virus/GI.1 (P1) virus strain. Results were compared to those previously determined using HBGA-blocking assays. RESULTS: Neutralizing antibody seroresponses were observed in 83% of 24 vaccinated adults, and antibody levels were highly correlated (r=0.81, P<0.001) with those measured by HBGA-blocking. CONCLUSIONS: GI.1-specific HBGA-blocking antibodies are a surrogate for neutralization of GI.1 norovirus.

2.
J Infect Dis ; 2023 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-37781879

RESUMO

A GII.2 outbreak in an efficacy study of a bivalent virus-like particle (VLP) norovirus vaccine, TAK-214, in healthy US adults provided an opportunity to examine GII.4 homotypic vs. GII.2 heterotypic responses to vaccination and infection. Three serological assays (VLP-binding, histoblood group antigen-blocking, and neutralizing) were performed for each genotype. Results were highly correlated within a genotype but not between genotypes. Although the vaccine provided protection from GII.2-associated disease, little GII.2-specific neutralization occurred after vaccination. Choice of antibody assay can affect assessments of human norovirus vaccine immunogenicity.

3.
Org Biomol Chem ; 21(12): 2603-2609, 2023 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-36896732

RESUMO

Cross-coupling and cascade reactions typically rely on unsustainable and toxic volatile organic solvents. 2,2,5,5-Tetramethyloxolane (TMO) and 2,5-diethyl-2,5-dimethyloxolane (DEDMO) are both inherently non-peroxide forming ethers, and have been used in this work as effective, more sustainable, and potentially bio-based alternative solvents for Suzuki-Miyaura and Sonogashira reactions. Suzuki-Miyaura reactions demonstrated good yields for a range of substrates, 71-89% in TMO and 63-92% in DEDMO. In addition, a Sonogashira reaction exhibited the excellent yields of 85-99% performed in TMO, which was significantly higher than traditional volatile organic solvents, THF or toluene, and higher than those reported for another non-peroxide forming ether, namely eucalyptol. Cascade Sonogashira reactions utilizing a simple annulation methodology were particularly effective in TMO. Furthermore, a green metric assessment confirmed that the methodology employing TMO was more sustainable and greener than the traditional solvents THF and toluene, thereby demonstrating the promise of TMO as an alternative solvent for Pd-catalyzed cross-coupling reactions.

4.
Molecules ; 27(23)2022 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-36500523

RESUMO

Green chemistry places an emphasis on safer chemicals, waste reduction, and efficiency. Processes should be optimized with green chemistry at the forefront of decision making, embedded into research at the earliest stage. To assist in this endeavor, we present a spreadsheet that can be used to interpret reaction kinetics via Variable Time Normalization Analysis (VTNA), understand solvent effects with linear solvation energy relationships (LSER), and calculate solvent greenness. With this information, new reaction conditions can be explored in silico, calculating product conversions and green chemistry metrics prior to experiments. The application of this tool was validated with literature case studies. Reaction performance was predicted and then confirmed experimentally for examples of aza-Michael addition, Michael addition, and an amidation. The combined analytical package presented herein permits a thorough examination of chemical reactions, so that the variables that control reaction chemistry can be understood, optimized, and made greener for research and education purposes.


Assuntos
Química Verde , Solventes
5.
Molecules ; 25(21)2020 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-33167453

RESUMO

It is a pleasure to write this editorial highlighting some of the recent papers discussing solvents in the Green Chemistry section of Molecules [...].


Assuntos
Química Verde , Solventes/química , Inteligência Artificial , Interações Hidrofóbicas e Hidrofílicas
6.
J Infect Dis ; 220(4): 603-614, 2019 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-31001633

RESUMO

BACKGROUND: We previously reported the tolerability and immunogenicity 1 month after intramuscular administration of 2 bivalent virus-like particle (VLP)-based candidate norovirus vaccine formulations in adults. We now describe the persistence of immunity and responses to a memory probe vaccination 1 year later. METHODS: A total of 454 healthy men and women aged 18-49 years in 3 equal groups received placebo (saline) or 15/50 or 50/50 vaccine formulations (ie, 15 or 50 µg of GI.1 genotype VLPs, respectively, and 50 µg of GII.4c VLPs) with MPL and Al(OH)3. Immunogenicity and safety were assessed up to day 365, when 351 participants received a memory probe vaccination of 15 µg each of GI.1 and GII.4c VLPs with Al(OH)3. RESULTS: No safety signals were detected up to 1 year after the first vaccination. Pan-immunoglobulin, immunoglobulin A, and histo-blood group antigen-blocking (HBGA) antibody levels among vaccinees waned but remained higher than levels before vaccination and levels in placebo recipients on days 180 and 365. Memory probe vaccination increased all antibody titers. Levels of HBGA antibodies to GI.1 but not GII.4c were higher after the first vaccination in candidate vaccine groups, compared with those in the placebo group. CONCLUSION: Levels of antibodies to both candidate norovirus VLP formulations persisted above baseline levels for at least 1 year after primary vaccination. HBGA-blocking responses to the memory probe for GI.1 but not GII.4c displayed characteristics of immune memory. CLINICAL TRIALS REGISTRATION: NCT02142504.


Assuntos
Antígenos de Grupos Sanguíneos , Infecções por Caliciviridae/prevenção & controle , Norovirus/imunologia , Vacinação , Vacinas de Partículas Semelhantes a Vírus/imunologia , Vacinas Virais/imunologia , Adolescente , Adulto , Infecções por Caliciviridae/sangue , Infecções por Caliciviridae/virologia , Método Duplo-Cego , Feminino , Humanos , Imunização Secundária , Imunogenicidade da Vacina , Masculino , Pessoa de Meia-Idade , Estados Unidos , Adulto Jovem
7.
Beilstein J Org Chem ; 16: 1001-1005, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32509031

RESUMO

The development and study of new solvents has become important due to a proliferation of regulations preventing or limiting the use of many conventional solvents. In this work, the suitability of the Suzuki-Miyaura reaction to demonstrate the usefulness of new solvents was evaluated, including Cyrene™, dimethyl isosorbide, ethyl lactate, 2-methyltetrahydrofuran (2-MeTHF), propylene carbonate, and γ-valerolactone (GVL). It was found that the cross coupling is often unaffected by the choice of solvent, and therefore the Suzuki-Miyaura reaction provides limited information regarding the usefulness of any particular solvent for organic synthesis.

8.
Molecules ; 24(12)2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31200457

RESUMO

There is demand for safer and bio-based solvents, brought on by legislation and sustainability objectives. The prediction of physical properties is highly desirable to help design new molecules. Here we present an in silico approach to obtain calculated Kamlet-Abboud-Taft solvatochromic parameters using virtual experiments. The tautomerisation equilibrium of methyl acetoacetate and dimedone was calculated in different solvents with COSMO-RS theory and converted into estimates of solvent dipolarity and hydrogen bond accepting ability, respectively. Hydrogen bond donating ability was calculated as a function of the electron deficient surface area on protic solvents. These polarity descriptors correlate with rate constants and equilibria, and so ability of calculated Kamlet-Abboud-Taft solvatochromic parameters to recreate experimental free energy relationships was tested with sixteen case studies taken from the literature. The accuracy of the calculated parameters was also satisfactory for solvent selection, as demonstrated with a 1,4-addition reaction and a multicomponent heterocycle synthesis.


Assuntos
Solventes/química , Ligação de Hidrogênio , Cinética
9.
J Infect Dis ; 217(4): 597-607, 2018 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-29140444

RESUMO

Background: We investigated safety and immunogenicity of 1-2 doses of different bivalent virus-like particle (VLP) norovirus vaccine candidate (NoV) formulations in healthy 18- to 64-year-olds. Methods: On days 1 and 28, participants (n = 420) randomized to 14 equal groups received intramuscular control vaccine (hepatitis A) or 1 of 11 NoV formulations containing varying dosages of GI.1 and GII.4c genotype VLP antigens with aluminum hydroxide [Al(OH)3], and 0 µg, 15 µg, or 50 µg monophosphoryl lipid A (MPL). Immunogenicity was assessed on days 1, 28, 56, 208 and 393. Solicited local and systemic reactions were recorded for 7 days, unsolicited adverse events (AEs) until day 56, and serious AEs throughout the trial. Results: All NoV formulations induced similar increases in pan-immunoglobulin, immunoglobulin A, and histo-blood group binding antigen-blocking antibodies by day 56, mostly after 1 dose, that persisted above baseline to day 393. Higher GI.1 content interfered with GII.4c responses, and responses did not benefit from MPL. Overall reactogenicity consisted of mainly mild injection site pain, headache, and fatigue. No vaccine-related serious AEs were reported. Conclusions: All candidate NoV formulations were well tolerated. Overall, 15 µg GI.1/50 µg GII.4c elicited the best balance of immunogenicity with no clear benefit of MPL, and is the candidate formulation being taken forward in clinical development. Clinical Trials Registration: NCT02038907.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Caliciviridae/prevenção & controle , Vacinas Virais/efeitos adversos , Vacinas Virais/imunologia , Adolescente , Adulto , Formação de Anticorpos , Método Duplo-Cego , Composição de Medicamentos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/epidemiologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Feminino , Genótipo , Voluntários Saudáveis , Humanos , Esquemas de Imunização , Injeções Intramusculares , Masculino , Pessoa de Meia-Idade , Norovirus/genética , Norovirus/imunologia , Vacinas Virais/administração & dosagem , Adulto Jovem
10.
Angew Chem Int Ed Engl ; 57(43): 14286-14290, 2018 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-29927034

RESUMO

Plan B: 1,2-Dichloroethane was recently subject to regulatory controls in the European Union that will severely limit its commercial use. The practitioners of innovative synthetic methods, particularly C-H bond activation, need to investigate alternative solvents if their chemistry is to stay relevant.


Assuntos
Dicloretos de Etileno/química , Solventes/química
11.
Faraday Discuss ; 202: 157-173, 2017 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-28661518

RESUMO

Many traditional solvents have drawbacks including sustainability and toxicity issues. Legislation, such as REACH, is driving the move towards less hazardous chemicals and production processes. Therefore, safer bio-based solvents need to be developed. Herein, a 10 step method has been proposed for the development of new bio-based solvents, which utilises a combination of in silico modelling of Hansen solubility parameters (HSPs), experimental Kamlet-Abboud-Taft parameters, a selection of green synthetic routes followed by application testing and toxicity measurements. The challenges that the chemical industry face in the development of new bio-based solvents are highlighted through a case study on methyl(2,2-dimethyl-1,3-dioxolan-4-yl)methyl carbonate (MMC), which can be synthesised from glycerol. Although MMC is an attractive candidate as a replacement solvent, simply being bio-derived is not enough for a molecule to be regarded as green. The methodology of solvent development described here is a broadly applicable protocol that will indicate if a new bio-based solvent is functionally proficient, and will also highlight the importance of early stage Kamlet-Abboud-Taft parameters determination and toxicity testing in the development of a green solvent.


Assuntos
Formiatos/síntese química , Formiatos/química , Estrutura Molecular , Solventes/síntese química , Solventes/química
12.
Molecules ; 22(1)2016 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-28036077

RESUMO

Bio-based products are made from renewable materials, offering a promising basis for the production of sustainable chemicals, materials, and more complex articles. However, biomass is not a limitless resource or one without environmental and social impacts. Therefore, while it is important to use biomass and grow a bio-based economy, displacing the unsustainable petroleum basis of energy and chemical production, any resource must be used effectively to reduce waste. Standards have been developed to support the bio-based product market in order to achieve this aim. However, the design of bio-based products has not received the same level of attention. Reported here are the first steps towards the development of a framework of understanding which connects product design to resource efficiency. Research and development scientists and engineers are encouraged to think beyond simple functionality and associate value to the potential of materials in their primary use and beyond.


Assuntos
Biomassa , Química Verde/métodos , Indústria Manufatureira/métodos , Reciclagem/métodos , Meio Ambiente
13.
J Clin Microbiol ; 53(8): 2768-72, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26063852

RESUMO

Eastern equine encephalitis diagnostic serum antibody can appear 6 days after the onset of symptoms, and its numbers can increase 4-fold in 4 days, arguing for early and frequent serum testing. In populations where cerebrospinal fluid viral nucleic acid testing sensitivity and specificity remain undetermined, cerebrospinal antibody testing should also be performed.


Assuntos
Anticorpos Antivirais/sangue , Anticorpos Antivirais/líquido cefalorraquidiano , Líquido Cefalorraquidiano/imunologia , Encefalomielite Equina do Leste/diagnóstico , Encefalomielite Equina do Leste/patologia , Soro/imunologia , Adulto , Idoso , Animais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , RNA Viral/sangue , RNA Viral/líquido cefalorraquidiano
14.
Int J Mol Sci ; 16(8): 17101-59, 2015 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-26225963

RESUMO

The global bio-based chemical market is growing in size and importance. Bio-based solvents such as glycerol and 2-methyltetrahydrofuran are often discussed as important introductions to the conventional repertoire of solvents. However adoption of new innovations by industry is typically slow. Therefore it might be anticipated that neoteric solvent systems (e.g., ionic liquids) will remain niche, while renewable routes to historically established solvents will continue to grow in importance. This review discusses bio-based solvents from the perspective of their production, identifying suitable feedstocks, platform molecules, and relevant product streams for the sustainable manufacturing of conventional solvents.


Assuntos
Biocombustíveis , Recuperação e Remediação Ambiental/métodos , Química Verde/métodos , Solventes/efeitos adversos , Solventes/química , Solventes/economia , Tensoativos/efeitos adversos , Tensoativos/química , Tensoativos/economia
15.
ChemSusChem ; 17(8): e202301639, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38200662

RESUMO

As of December 2023, the use of common solvent N,N-dimethyl formamide (DMF) will be restricted in the European Union because of its reproductive health hazard. Industrial facilities must comply with stricter exposure limits, and researchers are recommended to find alternative solvents. Here we explain the restrictions on DMF, which disciplines are affected, and how to substitute DMF to keep research and development commercially relevant.


Assuntos
Dimetilformamida , Solventes , Dimetilformamida/química , Solventes/química , União Europeia , Pesquisa , Humanos
16.
Chemistry ; 19(16): 5174-82, 2013 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-23436300

RESUMO

The traditional Biginelli reaction is a three-component condensation between urea, benzaldehyde and an acetoacetate ester to give a dihydropyrimidinone. An investigation into catalytic and solvent effects has returned the conclusion that the diketo-enol tautomerisation equilibrium of the dicarbonyl reactant dictates the yield of the reaction. Whereas the solvent is responsible for the tautomerisation equilibrium position, the catalyst only serves to eliminate kinetic control from the reaction. Generally, to preserve reaction efficiency and improve sustainability, bio-derivable p-cymene was found to be a useful solvent. The metal-enolate intermediate that results from the application of a Lewis acidic catalyst often cited as promoting the reaction appears to hinder the reaction. In this instance, a Brønsted acidic solvent can be used to return greater reactivity to the dicarbonyl reagent.

17.
Anal Methods ; 15(5): 596-605, 2023 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-36637024

RESUMO

Dichloromethane (DCM) is a useful and advantageous solvent used in pharmaceutical development due to its low cost, miscibility with other organic solvents, high volatility, and ability to solubilize drug molecules of variable polarities and functionalities. Despite this favourable behaviour, efforts to identify safer and more sustainable alternatives to hazardous, halogenated solvents is imperative to the expansion of green chemistry. In this work, bio-derived esters tert-butyl acetate, sec-butyl acetate, ethyl isobutyrate, and methyl pivalate are experimentally identified as safe and sustainable alternatives to directly replace DCM within thin-layer chromatography (TLC) in the analysis of small, common drug molecules. To elucidate the intermolecular interactions influencing retardation factors (Rf) a statistical thermodynamic framework, which quantifies the driving molecular interactions that yield empirical TLC measurements, is presented. Within this framework, we are able to deduce Rf dependence on polar eluent concentration, in the presence of a low-polar mediating solvent, between the stationary and mobile phases. The strength of competitive analyte-eluent (and analyte-solvent interactions) are quantified through Kirkwood-Buff integrals (KBIs); resulting KBI terms at the dilute eluent limit provide a theoretical foundation for the observed suitability of alternative green solvents for the replacement of dichloromethane in TLC.

18.
Musculoskeletal Care ; 21(1): 272-282, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36101975

RESUMO

BACKGROUND: Strategies are needed to improve referral into, and uptake of, osteoarthritis (OA) management programs. This survey investigated and compared patients' and medical professionals' views around hip and knee OA management and factors impacting implementation of an osteoarthritis management program. METHODS: As part of a mixed-methods program of research, patients with hip or knee OA and medical professionals routinely involved in the management of OA, were invited to complete a comprehensive online survey. All data were analysed descriptively or using chi squared tests. Survey findings for factors perceived to impact implementation of an OA management programme were triangulated with previously reported qualitative data. RESULTS: Fifty-three patients (38 females, 15 males) and 32 medical professionals (orthopaedic surgeons, sports physicians, rehabilitation physicians, rheumatologists and general practitioners) completed the survey. Twenty-eight patients (53%) had prior participation in the OA management programme (GLA:D® ) and 19 medical professionals (59%) had previously referred patients to the programme. Of the participants with prior exposure, 21 patients (75%) and 15 medical professionals (79%) agreed the programme was beneficial. A higher proportion of medical professionals, compared to patients, believed weight loss (100% vs. 67%), injection therapy (50% vs. 21%), hip replacement (100% vs. 62%) and knee replacement (97% vs. 62%) were effective treatments, with no differences for all other treatments. The barriers and enablers identified for referral into, and participation in, an OA management programme mostly aligned to factors identified in previous related qualitative research. Divergent factors in the survey included patients concerns about doing exercise-therapy with 81% (higher than expected) not reporting any concerns about exercising, and 19% (lower than expected) concerned about their OA joint, such as making their pain worse. CONCLUSIONS: This study has extended our understanding of barriers and enablers for referral into, and participation in, an OA management programme with a lower than expected number of patients being concerned about exercising due to their OA joint. Patients and medical professionals had positive views relating to the quality of the programme delivery, patient satisfaction and programme effectiveness. Medical professionals were more likely than patients to consider weight loss, injections and joint replacement as effective treatment options.


Assuntos
Osteoartrite do Quadril , Osteoartrite do Joelho , Masculino , Feminino , Humanos , Osteoartrite do Joelho/reabilitação , Osteoartrite do Quadril/terapia , Terapia por Exercício/métodos , Exercício Físico , Dor
19.
Hum Vaccin Immunother ; 19(1): 2204787, 2023 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-37140558

RESUMO

We conducted a dose-finding phase 2 study of the HilleVax bivalent virus-like particle (VLP) vaccine candidate (HIL-214) in two cohorts of children, 6-≤12 months and 1-≤4 years of age (N = 120 per cohort), in Panama and Colombia (ClinicalTrials.gov, identifier NCT02153112). On Day 1, children randomized to one of the four equal groups received intramuscular injections of four different HIL-214 formulations containing 15/15, 15/50, 50/50, or 50/150 µg of GI.1/GII.4c genotype VLPs and 0.5 mg Al(OH)3. On Day 29, half the children in each group received a second vaccination (N = 60), while the other half received saline placebo injections to maintain the blind. VLP-specific ELISA Pan-Ig and histo-blood group binding antigen-blocking antibodies (HBGA) were measured on Days 1, 29, 57 and 210. On Day 29, after one dose, there were large Pan-Ig and HBGA responses in both age cohorts with some indication of dose-dependence, and higher geometric mean titers (GMT) in the older children. A further increase in titers was observed 28 days after a second dose in the 6-≤12-month-old groups, but less so in the 1-≤4-year-old groups; GMTs at Day 57 were broadly similar across doses and in both age groups. GMTs of Pan-Ig and HBGA persisted above baseline up to Day 210. All formulations were well tolerated with mostly mild-to-moderate transient solicited adverse events reported by parents/guardians, and no vaccine-related serious adverse events occurred. Further development of HIL-214 is warranted to protect the most susceptible young children against norovirus.


Assuntos
Norovirus , Vacinas de Partículas Semelhantes a Vírus , Pré-Escolar , Humanos , Lactente , Anticorpos Antivirais , Método Duplo-Cego , Imunogenicidade da Vacina , Injeções Intramusculares
20.
Sci Rep ; 12(1): 2699, 2022 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-35177674

RESUMO

The development of covalent inhibitors against KRAS G12C represents a major milestone in treatment of RAS-driven cancers, especially in non-small cell lung cancer (NSCLC), where KRAS G12C is one of the most common oncogenic driver. Here we investigated if additional KRAS mutations co-occur with KRAS G12C (c.34G>T) in NSCLC tumours and if such mutation co-occurrence affects cellular response to G12C-specific inhibitors. Analysis of a large cohort of NSCLC patients whose tumours harboured KRAS mutations revealed co-occurring KRAS mutations in up to 8% of tumours with the KRAS c.34G>T mutation. KRAS c.35G>T was the most frequently co-occurring mutation, and could occur on the same allele (in cis) translating to a single mutant KRAS G12F protein, or on the other allele (in trans), translating to separate G12C and G12V mutant proteins. Introducing KRAS c.35G>T in trans in the KRAS G12C lung cancer model NCI-H358, as well as the co-occurrence in cis in the KRAS G12F lung cancer model NCI-H2291 led to cellular resistance to the G12C-specific inhibitor AZ'8037 due to continuing active MAPK and PI3K cascades in the presence of the inhibitor. Overall, our study provides a comprehensive assessment of co-occurring KRAS mutations in NSCLC and in vitro evidence of the negative impact of co-occurring KRAS mutations on cellular response to G12C inhibitors, highlighting the need for a comprehensive KRAS tumour genotyping for optimal patient selection for treatment with a KRAS G12C inhibitor.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Mutação/genética , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Proteínas Proto-Oncogênicas p21(ras)/genética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Humanos , Taxa de Mutação , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Estudos Retrospectivos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA