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1.
Chemistry ; : e202401581, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38771299

RESUMO

Transition metal carbides find widespread use throughout industry due to their high strength and resilience under extreme conditions. However, they remain largely limited to compounds formed from the early d-block elements, since the mid-to-late transition metals do not form thermodynamically stable carbides. We report here the high-pressure bulk synthesis of large single crystals of a novel metastable manganese carbide compound,MnCxP63/mmc, which adopts the anti-NiAs-type structure with significant substoichiometry at the carbon sites. We demonstrate how synthesis pressure modulates the carbon loading, with~40% occupancy being achieved at 9.9 GPa.

2.
ChemSusChem ; 16(20): e202300750, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37419862

RESUMO

The selective transformation of lignin to value-added biochemicals (e. g., phenolic acids) in high yields is incredibly challenging due to its structural complexity and many possible reaction pathways. Phenolic acids (PA) are key building blocks for various aromatic polymers, but the isolation of PAs from lignin is below 5 wt.% and requires harsh reaction conditions. Herein, we demonstrate an effective route to selectively convert lignin extracted from sweet sorghum and poplar into isolated PA in a high yield (up to 20 wt.% of lignin) using a low-cost graphene oxide-urea hydrogen peroxide (GO-UHP) catalyst under mild conditions (<120 °C). The lignin conversion yield is up to 95 %, and the remaining low molecular weight organic oils are ready for aviation fuel production to complete lignin utilization. Mechanistic studies demonstrate that pre-acetylation allows the selective depolymerization of lignin to aromatic aldehydes with a decent yield by GO through the Cα activation of ß-O-4 cleavage. A urea-hydrogen peroxide (UHP) oxidative process is followed to transform aldehydes in the depolymerized product to PAs by avoiding the undesired Dakin side reaction due to the electron-withdrawing effect of the acetyl group. This study opens a new way to selectively cleave lignin side chains to isolated biochemicals under mild conditions.


Assuntos
Hidroxibenzoatos , Lignina , Lignina/química , Polimerização , Catálise , Aldeídos
3.
J Am Pharm Assoc (2003) ; 61(3): e133-e137, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33622559

RESUMO

BACKGROUND: Pharmacists are critical to public health in supporting safe use of prescription opioids by ensuring that all patients are offered and counseled on naloxone. Academic detailing may be an effective educational outreach strategy for improving pharmacists' knowledge and behavior related to naloxone. OBJECTIVE: To describe an academic detailing program to pharmacists on the topic of counseling and promoting naloxone to patients. METHODS: Pharmacists were recruited by convenience sampling. Three pharmacists who were experienced with academic detailing techniques provided the education. Survey data were collected to evaluate the program. RESULTS: Thirty-three pharmacists participated, including 16 sessions that were delivered virtually. The pharmacists worked in a variety of ambulatory settings, including chain or corporate-owned pharmacies (58%), hospital-owned specialty pharmacies (15%), hospital-owned community pharmacies (15%), and independently owned or other pharmacies (12%). Twenty-eight pharmacists (85%) completed an immediate post-session evaluation survey. Twenty-seven pharmacists (96%) indicated they felt the information presented will impact their practice or patient care. Eleven pharmacists (33%) completed a second post-session survey, self-reporting improvements related to counseling patients about naloxone. CONCLUSION: Participating in academic detailing supports community pharmacists' providing patient counseling about naloxone. Further study, particularly related to virtual academic detailing, is necessary to understand the full potential of academic detailing to pharmacists.


Assuntos
Naloxona , Farmácias , Aconselhamento , Humanos , Antagonistas de Entorpecentes , Farmacêuticos
4.
J Public Health Dent ; 78(1): 25-31, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-28590563

RESUMO

OBJECTIVES: To implement and study the effect of improving pediatric oral health by training primary care practices and training programs. METHOD: In six New England States, primary care practices and clinical training programs (medical schools, residencies, physician assistant programs) were recruited and trained to incorporate pediatric oral health into medical practice. We measured the results of varying practice recruitment approaches and measured training outcomes based on self-reported implementation and state reported EPSDT CMS oral health claims. RESULTS: We trained 415 practices across six states with a 74 percent average retention rate of providing services at 6 months. This resulted in 136,963 preventive oral health services (fluoride varnish, oral health assessment, or screening). Thirty-five of 52 health education programs established pediatric oral health curricula. The average cost of recruitment, training, and follow-up for an office or an educational program is approximately $1,000/site. CONCLUSION: We have created an enduring infrastructure and model for primary care practices and education programs for training in pediatric oral health.


Assuntos
Saúde Bucal , Atenção Primária à Saúde , Criança , Currículo , Humanos
5.
Front Plant Sci ; 8: 456, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28421092

RESUMO

The production of reactive oxygen species (ROS) is one of the first defense reactions induced in Arabidopsis in response to infection by the pectinolytic enterobacterium Dickeya dadantii. Previous results also suggest that abscisic acid (ABA) favors D. dadantii multiplication and spread into its hosts. Here, we confirm this hypothesis using ABA-deficient and ABA-overproducer Arabidopsis plants. We investigated the relationships between ABA status and ROS production in Arabidopsis after D. dadantii infection and showed that ABA status modulates the capacity of the plant to produce ROS in response to infection by decreasing the production of class III peroxidases. This mechanism takes place independently of the well-described oxidative stress related to the RBOHD NADPH oxidase. In addition to this weakening of plant defense, ABA content in the plant correlates positively with the production of some bacterial virulence factors during the first stages of infection. Both processes should enhance disease progression in presence of high ABA content. Given that infection increases transcript abundance for the ABA biosynthesis genes AAO3 and ABA3 and triggers ABA accumulation in leaves, we propose that D. dadantii manipulates ABA homeostasis as part of its virulence strategy.

6.
Prehosp Disaster Med ; 27(2): 148-52, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22588429

RESUMO

INTRODUCTION: Mobile health (mHealth) technology can play a critical role in improving disaster victim tracking, triage, patient care, facility management, and theater-wide decision-making. PROBLEM: To date, no disaster mHealth application provides responders with adequate capabilities to function in an austere environment. METHODS: The Operational Medicine Institute (OMI) conducted a qualitative trial of a modified version of the off-the-shelf application iChart at the Fond Parisien Disaster Rescue Camp during the large-scale response to the January 12, 2010 earthquake in Haiti. RESULTS: The iChart mHealth system created a patient log of 617 unique entries used by on-the-ground medical providers and field hospital administrators to facilitate provider triage, improve provider handoffs, and track vulnerable populations such as unaccompanied minors, pregnant women, traumatic orthopedic injuries and specified infectious diseases. CONCLUSION: The trial demonstrated that even a non-disaster specific application with significant programmatic limitations was an improvement over existing patient tracking and facility management systems. A unified electronic medical record and patient tracking system would add significant value to first responder capabilities in the disaster response setting.


Assuntos
Telefone Celular , Terremotos , Sistemas Computadorizados de Registros Médicos/organização & administração , Traumatismo Múltiplo/terapia , Socorro em Desastres/organização & administração , Telemedicina , Triagem , Feminino , Haiti , Humanos , Masculino
7.
Mol Plant Pathol ; 13(8): 816-27, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22375884

RESUMO

Iron is an essential element for most living organisms, and pathogens are likely to compete with their hosts for the acquisition of this element. The bacterial plant pathogen Dickeya dadantii has been shown to require its siderophore-mediated iron uptake system for systemic disease progression on several host plants, including Arabidopsis thaliana. In this study, we investigated the effect of the iron status of Arabidopsis on the severity of disease caused by D. dadantii. We showed that symptom severity, bacterial fitness and the expression of bacterial pectate lyase-encoding genes were reduced in iron-deficient plants. Reduced symptoms correlated with enhanced expression of the salicylic acid defence plant marker gene PR1. However, levels of the ferritin coding transcript AtFER1, callose deposition and production of reactive oxygen species were reduced in iron-deficient infected plants, ruling out the involvement of these defences in the limitation of disease caused by D. dadantii. Disease reduction in iron-starved plants was also observed with the necrotrophic fungus Botrytis cinerea. Our data demonstrate that the plant nutritional iron status can control the outcome of an infection by acting on both the pathogen's virulence and the host's defence. In addition, iron nutrition strongly affects the disease caused by two soft rot-causing plant pathogens with a large host range. Thus, it may be of interest to take into account the plant iron status when there is a need to control disease without compromising crop quality and yield in economically important plant species.


Assuntos
Arabidopsis/imunologia , Botrytis/patogenicidade , Enterobacteriaceae/patogenicidade , Deficiências de Ferro , Arabidopsis/genética , Arabidopsis/microbiologia , Genes de Plantas , Polissacarídeo-Liases/genética , RNA Mensageiro/genética , Espécies Reativas de Oxigênio/metabolismo
8.
PLoS One ; 6(4): e18991, 2011 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-21533045

RESUMO

Dickeya dadantii is a broad host range phytopathogenic bacterium provoking soft rot disease on many plants including Arabidopsis. We showed that, after D. dadantii infection, the expression of the Arabidopsis BOS1 gene was specifically induced by the production of the bacterial PelB/C pectinases able to degrade pectin. This prompted us to analyze the interaction between the bos1 mutant and D. dadantii. The phenotype of the infected bos1 mutant is complex. Indeed, maceration symptoms occurred more rapidly in the bos1 mutant than in the wild type parent but at a later stage of infection, a necrosis developed around the inoculation site that provoked a halt in the progression of the maceration. This necrosis became systemic and spread throughout the whole plant, a phenotype reminiscent of that observed in some lesion mimic mutants. In accordance with the progression of maceration symptoms, bacterial population began to grow more rapidly in the bos1 mutant than in the wild type plant but, when necrosis appeared in the bos1 mutant, a reduction in bacterial population was observed. From the plant side, this complex interaction between D. dadantii and its host includes an early plant defence response that comprises reactive oxygen species (ROS) production accompanied by the reinforcement of the plant cell wall by protein cross-linking. At later timepoints, another plant defence is raised by the death of the plant cells surrounding the inoculation site. This plant cell death appears to constitute an efficient defence mechanism induced by D. dadantii during Arabidopsis infection.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/microbiologia , Enterobacteriaceae/patogenicidade , Mutação , Fatores de Transcrição/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Necrose , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo
9.
J Gen Intern Med ; 26(1): 40-4, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20809157

RESUMO

BACKGROUND: The pharmaceutical industry spends billions of dollars annually to encourage clinicians to prescribe their medications. Small studies have demonstrated that one of the marketing strategies, the distribution of free sample medications, is associated with increased use of brand name medication over generic medication. OBJECTIVES: To determine the relationship between the presence of drug samples in primary care clinics and prescription of preferred drug treatments. DESIGN: Cross-sectional survey. PARTICIPANTS: Primary care prescribers in the state of Vermont. MAIN MEASUREMENT: Prescribers were presented with two clinical vignettes and asked to provide the name of the medication they would prescribe in each case. We compared the responses of prescribers with and without samples in their clinics. KEY RESULTS: Two hundred six prescribers out of the total population of 631 returned the survey and met the eligibility criteria. Seventy-two percent of prescribers had sample closets in their clinics. Seventy percent of clinicians with samples would prescribe a thiazide diuretic for hypertension compared to 91% in those without samples (P<0.01). For managing depression 91% of prescribers with samples would have provided a generic medication in a patient with no health insurance, compared to 100% of those without samples in their clinic (P=0.02). CONCLUSIONS: Clinicians with samples in their clinics were less likely to prescribe preferred medications for hypertension and depression.


Assuntos
Indústria Farmacêutica/economia , Prescrições de Medicamentos/economia , Padrões de Prática Médica/economia , Autorrelato , Adulto , Idoso , Estudos Transversais , Indústria Farmacêutica/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vermont
10.
Mol Plant Microbe Interact ; 23(10): 1324-34, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20672878

RESUMO

The fungal cell wall is a dynamic structure that protects the cell from different environmental stresses suggesting that wall synthesizing enzymes are of great importance for fungal virulence. Previously, we reported the isolation and characterization of a mutant in class III chitin synthase, Bcchs3a, in the phytopathogenic fungus Botrytis cinerea. We demonstrated that virulence of this mutant is severely impaired. Here, we describe the virulence phenotype of the cell-wall mutant Bcchs3a on the model plant Arabidopsis thaliana and analyze its virulence properties, using a variety of A. thaliana mutants. We found that mutant Bcchs3a is virulent on pad2 and pad3 mutant leaves defective in camalexin. Mutant Bcchs3a was not more susceptible towards camalexin than the wild-type strain but induced phytoalexin accumulation at the infection site on Col-0 plants. Moreover, this increase in camalexin was correlated with overexpression of the PAD3 gene observed as early as 18 h postinoculation. The infection process of the mutant mycelium was always delayed by 48 h, even on pad3 plants, probably because of lack of mycelium adhesion. No loss in virulence was found when Bcchs3a conidia were used as the inoculum source. Collectively, these data led us to assign a critical role to the BcCHS3a chitin synthase isoform, both in fungal virulence and plant defense response.


Assuntos
Botrytis/genética , Botrytis/metabolismo , Quitina Sintase/genética , Quitina Sintase/metabolismo , Regulação Fúngica da Expressão Gênica/fisiologia , Doenças das Plantas/imunologia , Arabidopsis/imunologia , Arabidopsis/microbiologia , Botrytis/citologia , Botrytis/patogenicidade , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulação Enzimológica da Expressão Gênica , Indóis/metabolismo , Mutação , Tiazóis/metabolismo , Virulência
11.
Environ Microbiol ; 10(3): 545-59, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18177376

RESUMO

Pathogenicity of the phytopathogenic enterobacterium Erwinia chrysanthemi, the causal agent of soft rot disease on many plants, is a complex process involving several factors whose production is regulated by a complex, intertwined regulatory network. In this work we characterized the GacA regulator, member of the GacS-GacA two-component system, as a global regulator which is required for disease expression but not for bacterial multiplication in planta during the first stages of the plant infection. GacA was shown to control the expression of plant cell wall-degrading enzymes and hrp genes in vitro. Analysis of virulence gene expression during infection of Arabidopsis thaliana revealed a coordinated expression of these virulence genes at 12 h post infection and showed that GacA is required for the appropriate production of virulence factors in planta. GacA might partly act by negatively controlling the expression of the pecT gene encoding the global repressor PecT, indicating a hierarchy in the pathways involved in the E. chrysanthemi regulatory network.


Assuntos
Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/fisiologia , Dickeya chrysanthemi/patogenicidade , Genes Reguladores , Doenças das Plantas/microbiologia , Proteínas Repressoras/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Virulência/genética , Dickeya chrysanthemi/fisiologia , Regulação Bacteriana da Expressão Gênica , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Fatores de Virulência/fisiologia
12.
J Exp Bot ; 56(413): 945-58, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15710637

RESUMO

ADPglucose, the essential substrate for starch synthesis, is synthesized in maize by a pathway involving at least invertases, sucrose synthase, and ADPglucose pyrophosphorylase, as shown by the starch-deficient mutants, mn1, sh1, and bt2 or sh2, respectively. To improve understanding of the relationship between early grain-filling traits and carbohydrate composition in mature grain, QTLs linked to soluble invertase, sucrose synthase, and ADPglucose pyrophosphorylase activities and to starch, sucrose, fructose, and glucose concentrations were investigated. In order to take into account the specific time-course of each enzyme activity during grain filling, sampling was carried out at three periods (15, 25, and 35 d after pollination) on 100 lines from a recombinant inbred family, grown in the field. The MQTL method associated with QTL interaction analysis revealed numerous QTLs for all traits, but only one QTL was consistently observed at the three sampling periods. Some chromosome zones were heavily labelled, forming clusters of QTLs. Numerous possible candidate genes of the starch synthetic pathway co-located with QTLs. Four QTLs were found close to the locus Sh1 (bin 9.01) coding for the sucrose synthase. In order to confirm the importance of this locus, the CAPS polymorphism of the Sh1 gene was analysed in 45 genetically unrelated maize lines from various geographical origins. The DNA polymorphism was significantly associated with phenotypic traits related to grain filling (starch and amylose content, grain matter, and ADPglucose pyrophosphorylase activity at 35 DAP). Thus, the Sh1 locus could provide a physiologically pertinent marker for maize selection.


Assuntos
Metabolismo dos Carboidratos , Locos de Características Quantitativas , Sementes/crescimento & desenvolvimento , Amido/metabolismo , Zea mays/genética , Zea mays/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Regulação da Expressão Gênica de Plantas/fisiologia , Ligação Genética , Marcadores Genéticos , Glucose-1-Fosfato Adenililtransferase , Glucosiltransferases/metabolismo , Nucleotidiltransferases/metabolismo , Fenótipo , Polimorfismo Genético , Sementes/metabolismo , Fatores de Tempo , Zea mays/enzimologia , beta-Frutofuranosidase/metabolismo
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