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1.
J Appl Toxicol ; 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39168852

RESUMO

The novel genetically modified probiotic Bacillus subtilis ZB423 was assessed in a 90-day repeated-dose oral toxicity study adhering to Good Laboratory Practice (GLP) and Organization for Economic Cooperation and Development (OECD) guidelines. Spray-dried spores at a concentration of 1.1E12 CFU/g were administered at doses of 130, 260, and 519 mg/kg body weight/day correlating to 1.43 × 1011, 2.86 × 1011, and 5.71 × 1011 CFU/kg/day, respectively, by oral gavage to Wistar rats for a period of 90 consecutive days. Results showed no toxicologically relevant findings for B. subtilis ZB423 from measured parameters. The no observed adverse effect level (NOAEL) of B. subtilis ZB423 is 519 mg/kg body weight/day corresponding to 5.71 × 1011 CFU/kg/day for lyophilized B. subtilis ZB423 spores under the test conditions employed.

2.
J Biol Chem ; 294(2): 397-404, 2019 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-30478172

RESUMO

Homologous recombination (HR)-directed DNA double-strand break (DSB) repair enables template-directed DNA repair to maintain genomic stability. RAD51 recombinase (RAD51) is a critical component of HR and facilitates DNA strand exchange in DSB repair. We report here that treating triple-negative breast cancer (TNBC) cells with the fatty acid nitroalkene 10-nitro-octadec-9-enoic acid (OA-NO2) in combination with the antineoplastic DNA-damaging agents doxorubicin, cisplatin, olaparib, and γ-irradiation (IR) enhances the antiproliferative effects of these agents. OA-NO2 inhibited IR-induced RAD51 foci formation and enhanced H2A histone family member X (H2AX) phosphorylation in TNBC cells. Analyses of fluorescent DSB reporter activity with both static-flow cytometry and kinetic live-cell studies enabling temporal resolution of recombination revealed that OA-NO2 inhibits HR and not nonhomologous end joining (NHEJ). OA-NO2 alkylated Cys-319 in RAD51, and this alkylation depended on the Michael acceptor properties of OA-NO2 because nonnitrated and saturated nonelectrophilic analogs of OA-NO2, octadecanoic acid and 10-nitro-octadecanoic acid, did not react with Cys-319. Of note, OA-NO2 alkylation of RAD51 inhibited its binding to ssDNA. RAD51 Cys-319 resides within the SH3-binding site of ABL proto-oncogene 1, nonreceptor tyrosine kinase (ABL1), so we investigated the effect of OA-NO2-mediated Cys-319 alkylation on ABL1 binding and found that OA-NO2 inhibits RAD51-ABL1 complex formation both in vitro and in cell-based immunoprecipitation assays. The inhibition of the RAD51-ABL1 complex also suppressed downstream RAD51 Tyr-315 phosphorylation. In conclusion, RAD51 Cys-319 is a functionally significant site for adduction of soft electrophiles such as OA-NO2 and suggests further investigation of lipid electrophile-based combinational therapies for TNBC.


Assuntos
Antineoplásicos/administração & dosagem , Dano ao DNA/efeitos dos fármacos , Ácidos Graxos/administração & dosagem , Rad51 Recombinase/metabolismo , Neoplasias de Mama Triplo Negativas/enzimologia , Neoplasias de Mama Triplo Negativas/fisiopatologia , Alquilação , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Cisplatino/administração & dosagem , Reparo do DNA , Doxorrubicina/administração & dosagem , Quimioterapia Combinada , Ácidos Graxos/química , Humanos , Ligação Proteica/efeitos dos fármacos , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas c-abl/genética , Proteínas Proto-Oncogênicas c-abl/metabolismo , Rad51 Recombinase/química , Rad51 Recombinase/genética , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/metabolismo
3.
Phys Rev Lett ; 124(15): 152501, 2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32357059

RESUMO

The lifetimes of the first excited 2^{+} states in the N=Z nuclei ^{80}Zr, ^{78}Y, and ^{76}Sr have been measured using the γ-ray line shape method following population via nucleon-knockout reactions from intermediate-energy rare-isotope beams. The extracted reduced electromagnetic transition strengths yield new information on where the collectivity is maximized and provide evidence for a significant, and as yet unexplained, odd-odd vs even-even staggering in the observed values. The experimental results are analyzed in the context of state-of-the-art nuclear density-functional model calculations.

4.
Phys Rev Lett ; 121(3): 032502, 2018 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-30085775

RESUMO

Energy differences between analogue states in the T=1/2 ^{23}Mg-^{23}Na mirror nuclei have been measured along the rotational yrast bands. This allows us to search for effects arising from isospin-symmetry-breaking interactions (ISB) and/or shape changes. Data are interpreted in the shell model framework following the method successfully applied to nuclei in the f_{7/2} shell. It is shown that the introduction of a schematic ISB interaction of the same type of that used in the f_{7/2} shell is needed to reproduce the data. An alternative novel description, applied here for the first time, relies on the use of an effective interaction deduced from a realistic charge-dependent chiral nucleon-nucleon potential. This analysis provides two important results: (i) The mirror energy differences give direct insight into the nuclear skin; (ii) the skin changes along the rotational bands are strongly correlated with the difference between the neutron and proton occupations of the s_{1/2} "halo" orbit.

5.
J Comput Aided Mol Des ; 32(1): 287-297, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28918599

RESUMO

The goal of virtual screening is to generate a substantially reduced and enriched subset of compounds from a large virtual chemistry space. Critical in these efforts are methods to properly rank the binding affinity of compounds. Prospective evaluations of ranking strategies in the D3R grand challenges show that for targets with deep pockets the best correlations (Spearman ρ ~ 0.5) were obtained by our submissions that docked compounds to the holo-receptors with the most chemically similar ligand. On the other hand, for targets with open pockets using multiple receptor structures is not a good strategy. Instead, docking to a single optimal receptor led to the best correlations (Spearman ρ ~ 0.5), and overall performs better than any other method. Yet, choosing a suboptimal receptor for crossdocking can significantly undermine the affinity rankings. Our submissions that evaluated the free energy of congeneric compounds were also among the best in the community experiment. Error bars of around 1 kcal/mol are still too large to significantly improve the overall rankings. Collectively, our top of the line predictions show that automated virtual screening with rigid receptors perform better than flexible docking and other more complex methods.


Assuntos
Desenho Assistido por Computador , Desenho de Fármacos , Simulação de Acoplamento Molecular , Receptores Citoplasmáticos e Nucleares/metabolismo , Benzimidazóis/química , Benzimidazóis/farmacologia , Sítios de Ligação , Humanos , Isoxazóis/química , Isoxazóis/farmacologia , Ligantes , Ligação Proteica , Conformação Proteica , Receptores Citoplasmáticos e Nucleares/química , Compostos de Espiro/química , Compostos de Espiro/farmacologia , Sulfonamidas/química , Sulfonamidas/farmacologia , Termodinâmica
6.
Mol Plant Microbe Interact ; 29(12): 938-949, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-28001093

RESUMO

The nonprotein amino acid γ-aminobutyric acid (GABA) is the most abundant amino acid in the tomato (Solanum lycopersicum) leaf apoplast and is synthesized by Arabidopsis thaliana in response to infection by the bacterial pathogen Pseudomonas syringae pv. tomato DC3000 (hereafter called DC3000). High levels of exogenous GABA have previously been shown to repress the expression of the type III secretion system (T3SS) in DC3000, resulting in reduced elicitation of the hypersensitive response (HR) in the nonhost plant tobacco (Nicotiana tabacum). This study demonstrates that the GABA permease GabP provides the primary mechanism for GABA uptake by DC3000 and that the gabP deletion mutant ΔgabP is insensitive to GABA-mediated repression of T3SS expression. ΔgabP displayed an enhanced ability to elicit the HR in young tobacco leaves and in tobacco plants engineered to produce increased levels of GABA, which supports the hypothesis that GABA uptake via GabP acts to regulate T3SS expression in planta. The observation that P. syringae can be rendered insensitive to GABA through loss of gabP but that gabP is retained by this bacterium suggests that GabP is important for DC3000 in a natural setting, either for nutrition or as a mechanism for regulating gene expression. [Formula: see text] Copyright © 2016 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .


Assuntos
Sistemas de Transporte de Aminoácidos/metabolismo , Doenças das Plantas/imunologia , Pseudomonas syringae/efeitos dos fármacos , Solanum lycopersicum/imunologia , Sistemas de Secreção Tipo III/efeitos dos fármacos , Ácido gama-Aminobutírico/farmacologia , Sistemas de Transporte de Aminoácidos/genética , Arabidopsis/imunologia , Arabidopsis/microbiologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Solanum lycopersicum/microbiologia , Doenças das Plantas/microbiologia , Folhas de Planta/imunologia , Folhas de Planta/microbiologia , Pseudomonas syringae/metabolismo , Pseudomonas syringae/patogenicidade , Deleção de Sequência , Nicotiana/imunologia , Nicotiana/microbiologia , Virulência
7.
Antimicrob Agents Chemother ; 60(5): 2732-8, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26883711

RESUMO

Little has been done during the past 100 years to develop new antileishmanial drugs. Most infected individuals live in poor countries and have a low cash income to be attractive targets to pharmaceutical corporations. Two heterosidic steroids, solamargine and solasonine, initially identified as major components of the Brazilian plant Solanum lycocarpum, were tested for leishmanicidal activity. Both alkaloids killed intracellular and extracellular Leishmania mexicana parasites more efficiently than the reference drug sodium stibogluconate. A total of 10 µM each individual alkaloid significantly reduced parasite counts in infected macrophages and dendritic cells. In vivo treatment of C57BL/6 mice with a standardized topical preparation containing solamargine (45.1%) and solasonine (44.4%) gave significant reductions in lesion sizes and parasite counts recovered from lesions. Alkaloids present different immunochemical pathways in macrophages and dendritic cells. We conclude that this topical preparation is effective and a potential new and inexpensive treatment for cutaneous leishmaniasis.


Assuntos
Gluconato de Antimônio e Sódio/uso terapêutico , Antiprotozoários/uso terapêutico , Extratos Vegetais/uso terapêutico , Alcaloides de Solanáceas/uso terapêutico , Alcaloides/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Dendríticas/parasitologia , Feminino , Citometria de Fluxo , Frutas/química , Leishmania mexicana/efeitos dos fármacos , Leishmania mexicana/patogenicidade , Macrófagos/parasitologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Extratos Vegetais/química
8.
Phys Rev Lett ; 117(8): 082502, 2016 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-27588851

RESUMO

One-neutron knockout reactions have been performed on a beam of radioactive ^{53}Co in a high-spin isomeric state. The analysis is shown to yield a highly selective population of high-spin states in an exotic nucleus with a significant cross section, and hence represents a technique that is applicable to the planned new generation of fragmentation-based radioactive beam facilities. Additionally, the relative cross sections among the excited states can be predicted to a high level of accuracy when reliable shell-model input is available. The work has resulted in a new level scheme, up to the 11^{+} band-termination state, of the proton-rich nucleus ^{52}Co (Z=27, N=25). This has in turn enabled a study of mirror energy differences in the A=52 odd-odd mirror nuclei, interpreted in terms of isospin-nonconserving (INC) forces in nuclei. The analysis demonstrates the importance of using a full set of J-dependent INC terms to explain the experimental observations.

9.
J Comput Aided Mol Des ; 30(9): 695-706, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27573981

RESUMO

Induced fit or protein flexibility can make a given structure less useful for docking and/or scoring. The 2015 Drug Design Data Resource (D3R) Grand Challenge provided a unique opportunity to prospectively test optimal strategies for virtual screening in these type of targets: heat shock protein 90 (HSP90), a protein with multiple ligand-induced binding modes; and mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4), a kinase with a large flexible pocket. Using previously known co-crystal structures, we tested predictions from methods that keep the receptor structure fixed and used (a) multiple receptor/ligand co-crystals as binding templates for minimization or docking ("close"), (b) methods that align or dock to a single receptor ("cross"), and (c) a hybrid approach that chose from multiple bound ligands as initial templates for minimization to a single receptor ("min-cross"). Pose prediction using our "close" models resulted in average ligand RMSDs of 0.32 and 1.6 Å for HSP90 and MAP4K4, respectively, the most accurate models of the community-wide challenge. On the other hand, affinity ranking using our "cross" methods performed well overall despite the fact that a fixed receptor cannot model ligand-induced structural changes,. In addition, "close" methods that leverage the co-crystals of the different binding modes of HSP90 also predicted the best affinity ranking. Our studies suggest that analysis of changes on the receptor structure upon ligand binding can help select an optimal virtual screening strategy.


Assuntos
Desenho de Fármacos , Proteínas de Choque Térmico HSP90/química , Peptídeos e Proteínas de Sinalização Intracelular/química , Proteínas Serina-Treonina Quinases/química , Bibliotecas de Moléculas Pequenas/química , Algoritmos , Sítios de Ligação , Cristalografia por Raios X , Ligantes , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Interface Usuário-Computador
10.
Phys Rev Lett ; 115(5): 052702, 2015 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-26274415

RESUMO

26Al is an important radioisotope in astrophysics that provides evidence of ongoing nucleosynthesis in the Galaxy. The 23Na(α, p)26Mg reaction has been identified by a sensitivity study as being one of the most important reactions for the production of 26Al in the convective C/Ne burning shell of massive stars. Owing to large uncertainties in previous experimental data, model calculations are used for the reaction rate of 23Na(α, p)26Mg in this sensitivity study. Current experimental data suggest a reaction rate a factor of ∼40 higher than model calculations. However, a new measurement of this reaction cross section has been made in inverse kinematics in the energy range E(c.m.)=1.28-3.15 MeV at TRIUMF, and found to be in reasonable agreement with the model calculation. A new reaction rate is calculated and tight constraints on the uncertainty in the production of 26Al, due to this reaction, are determined.

11.
Rhinology ; 52(2): 127-32, 2014 06.
Artigo em Inglês | MEDLINE | ID: mdl-24932623

RESUMO

BACKGROUND: We aim to validate a clinical scoring system of external nasal valve collapse. External nasal valve collapse is a rare and challenging condition. We attempted to simplify the examination of the external valve, the surgical planning and the outcome measure. To validate our external valve score, we first assessed its reliability (inter-rater agreement and test-retest repeatability). We secondly considered the clinical relevance by using our scoring system in patients undergoing septorhinoplasty for external valve collapse. METHODOLOGY: For validation, 16 Rhinologists scored patients separately on two occasions. For the clinical relevance, 26 patients with external valve collapse were scored pre- and post-operatively (responsiveness). The external valve score was correlated to peak nasal inspiratory flow. RESULTS: The devised scoring system was reliable (substantial agreement between 16 surgeons with reproducibility over time). All patients in our prospective series showed significant improvement in their external valve score. The quality of life measured by the SNOT-22 tool showed significant improvement after surgery. CONCLUSION: External nasal valve collapse can be diagnosed and graded using this simple scoring system in the outpatient clinic. This paper reinforces the pivotal role of septorhinoplasty surgery in nasal airway reconstruction and the ongoing need to quantify success.


Assuntos
Cavidade Nasal/patologia , Obstrução Nasal/diagnóstico , Obstrução Nasal/etiologia , Rinoplastia , Adulto , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obstrução Nasal/cirurgia , Septo Nasal/cirurgia , Avaliação de Resultados em Cuidados de Saúde , Reprodutibilidade dos Testes , Índice de Gravidade de Doença
12.
Biochemistry ; 52(44): 7723-30, 2013 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-24147857

RESUMO

Plasmodium falciparum, a parasitic organism and one of the causative agents of malaria, contains an unusual organelle called the apicoplast. The apicoplast is a nonphotosynthetic plastid responsible for supplying the parasite with isoprenoid units and is therefore indispensable. Like mitochondria and the chloroplast, the apicoplast contains its own genome and harbors the enzymes responsible for its replication. In this report, we determine the relative probabilities of nucleotide misincorporation by the apicoplast polymerase (apPOL), examine the kinetics and sequence dependence of mismatch extension, and determine the rates of mismatch removal by the 3' to 5' proofreading activity of the DNA polymerase. While the intrinsic polymerase fidelity varies by >50-fold for the 12 possible nucleotide misincorporations, the most dominant selection step for overall polymerase fidelity is conducted at the level of mismatch extension, which varies by >350-fold. The efficiency of mismatch extension depends on both the nature of the DNA mismatch and the templating base. The proofreading activity of the 12 possible mismatches varies <3-fold. The data for these three determinants of polymerase-induced mutations indicate that the overall mutation frequency of apPOL is highly dependent on both the intrinsic fidelity of the polymerase and the identity of the template surrounding the potential mismatch.


Assuntos
Apicoplastos/enzimologia , Replicação do DNA , DNA Polimerase Dirigida por DNA/metabolismo , Plasmodium falciparum/enzimologia , Proteínas de Protozoários/metabolismo , Apicoplastos/genética , Apicoplastos/metabolismo , DNA Polimerase Dirigida por DNA/química , DNA Polimerase Dirigida por DNA/genética , Cinética , Nucleotídeos/genética , Nucleotídeos/metabolismo , Plasmodium falciparum/química , Plasmodium falciparum/genética , Proteínas de Protozoários/química , Proteínas de Protozoários/genética
13.
Phys Rev Lett ; 111(7): 072501, 2013 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-23992059

RESUMO

The first spectroscopy of excited states in 52Ni (T(z)=-2) and 51Co (T(z)=-3/2) has been obtained using the highly selective two-neutron knockout reaction. Mirror energy differences between isobaric analogue states in these nuclei and their mirror partners are interpreted in terms of isospin nonconserving effects. A comparison between large-scale shell-model calculations and data provides the most compelling evidence to date that both electromagnetic and an additional isospin nonconserving interactions for J=2 couplings, of unknown origin, are required to obtain good agreement.

14.
Phys Rev Lett ; 110(17): 172501, 2013 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-23679711

RESUMO

A measurement of the reduced transition probability for the excitation of the ground state to the first 2+ state in 104Sn has been performed using relativistic Coulomb excitation at GSI. 104Sn is the lightest isotope in the Sn chain for which this quantity has been measured. The result is a key point in the discussion of the evolution of nuclear structure in the proximity of the doubly magic nucleus 100Sn. The value B(E2; 0+ → 2+) = 0.10(4) e2b2 is significantly lower than earlier results for 106Sn and heavier isotopes. The result is well reproduced by shell model predictions and therefore indicates a robust N = Z = 50 shell closure.

15.
Vox Sang ; 105(4): 313-8, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23662653

RESUMO

BACKGROUND AND OBJECTIVES: Idiopathic thrombotic thrombocytopenic purpura (TTP) is a rare, clinically diagnosed disorder characterized by widespread intravascular platelet thrombosis. The pathophysiology involves acquired deficiency of ADAMTS13 (A disintegrin and metalloprotease with thrombospondin type 1 repeats), the enzyme responsible for cleavage of high molecular weight vonWillebrand factor multimers. Disease mortality is high, although prompt treatment with plasma exchange is generally effective. A readily available and highly reliable method of identifying ADAMTS13-deficient patients for appropriate plasma exchange is therefore of interest. MATERIALS AND METHODS: Our initial study involved the assessment of multiple clinical and laboratory variables in patients with clinically suspected TTP for whom ADAMTS13 assay was performed. Five variables were found to be of significant predictive power. This enabled the development of a point-based scoring system to efficiently determine the likelihood of TTP and response to plasma exchange in a given patient. This current study involved a separate validation cohort of patients with clinically suspected TTP who underwent ADAMTS13 testing within two large healthcare systems in Utah between 2009 and 2011. The previously derived score was applied to this cohort and its performance was analysed. Additionally, the original and validation cohorts were combined to revisit the predictive power of individual variables and the five-variable prediction score. RESULTS: A total of 84 (11 paediatric cases excluded) patients comprised the validation population. The percentage of TTP diagnoses in this group (10%) was identical to that in the initial cohort. Using an ADAMTS13 activity of <10% of normal, our original score correctly predicted or excluded severe ADAMTS13 deficiency in all patients in the second cohort when data for all variables was available. Individual variables retained predictive power and the performance of a three-variable parsimonious model, as well as the ultimate diagnoses for patients in the second cohort are described. CONCLUSION: This work confirms the predictive power of a simple point-based score to exclude TTP as evidenced by severe ADAMTS13 deficiency in appropriately selected patients. It may enable clinicians to rapidly begin plasma exchange or to pursue an alternative cause of thrombotic microangiopathy.


Assuntos
Proteínas ADAM/deficiência , Troca Plasmática , Púrpura Trombocitopênica Trombótica/terapia , Proteína ADAMTS13 , Estudos de Coortes , Humanos , Púrpura Trombocitopênica Trombótica/diagnóstico
16.
J Integr Neurosci ; 12(4): 513-28, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24372069

RESUMO

The aim of this research proposal was to investigate the effects of tetrahydropalmatine (THP) on gene expression in a post-traumatic stress disorder (PTSD) rodent model. Eighty male Sprague-Dawley rats were randomly assigned to the nonstressed groups or the 3-day restraint shock PTSD rodent model groups. There were four groups within the nonstressed rats (control, THP, midazolam, and midazolam with THP) and four groups within the stressed rats (control, THP, midazolam, and midazolam with THP). After injection the subjects were euthanized and the amygdala and hippocampus were sent for reverse transcriptase-polymerase chain reaction gene expression analysis. Of the genes interrogated, 17 genes in the amygdala and 18 genes in the hippocampus were found to have significant changes in gene expression and regulation. Significant transcriptional fold changes were found in important genes involved in dopamine, serotonin, acetylcholine, and gamma-aminobutyric acid neurotransmitter systems. The results provide quantifiable data demonstrating gene expression changes in PTSD-stressed and nonstressed rats receiving various treatments. These findings contribute important data to the limited molecular details pertaining to the neurobiology of PTSD.


Assuntos
Analgésicos não Narcóticos/farmacologia , Alcaloides de Berberina/farmacologia , Encéfalo/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Receptores de Neurotransmissores/metabolismo , Transtornos de Estresse Pós-Traumáticos/patologia , Adjuvantes Anestésicos/farmacologia , Adjuvantes Anestésicos/uso terapêutico , Analgésicos não Narcóticos/uso terapêutico , Análise de Variância , Animais , Alcaloides de Berberina/uso terapêutico , Encéfalo/metabolismo , Modelos Animais de Doenças , Masculino , Midazolam/farmacologia , Midazolam/uso terapêutico , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , RNA Mensageiro , Ratos , Ratos Sprague-Dawley , Receptores de Neurotransmissores/genética , Transtornos de Estresse Pós-Traumáticos/tratamento farmacológico
17.
J Econ Entomol ; 106(1): 97-106, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23448020

RESUMO

Wild bees that provide pollination services to vegetable crops depend on forage resources, nesting sites, and overwintering sites in the agricultural landscape. The scale at which crop-visiting bees use resources in the landscape can vary regionally, and has not been characterized in the Midwestern United States. We investigated the effects of seminatural land cover on wild bee visitation frequency to cucumber (Cucumis sativus L.) and on wild bee species richness on 10 organic farms in Indiana. We estimated the spatial scale at which the effects of land cover were strongest, and also examined the effects of nonlandscape factors on wild bees. The visitation frequency of wild bees to cucumber was positively related to the proportion of seminatural land in the surrounding landscape, and this relationship was strongest within 250 m of the cucumber patch. The species richness of wild cucumber visitors was not affected by land cover at any spatial scale, nor by any of the nonlandscape factors we considered. Our results indicate that wild, crop visiting bees benefit from seminatural areas in the agricultural landscape, and benefit most strongly from seminatural areas within 250 m of the crop field. This suggests that setting aside natural areas in the near vicinity of vegetable fields may be an effective way to support wild, crop-visiting bees and secure their pollination services.


Assuntos
Abelhas , Comportamento Animal , Biodiversidade , Animais , Cucumis sativus , Feminino , Indiana , Masculino , Agricultura Orgânica , Polinização
18.
Drug Dev Ind Pharm ; 37(1): 47-55, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20550424

RESUMO

BACKGROUND: The effectiveness of a water/oil (w/o) microemulsion containing quercetin against ultraviolet B radiation (UVB) induced damage was recently demonstrated by our group. However, during the development of new pharmaceutical products, the evaluation of percutaneous absorption and in vivo effectiveness should be accompanied by evaluation of stability parameters as an integral part of the process. OBJECTIVE: The aim was to investigate the stability of the final microemulsion formulation considering the temperature ranges of storage and application. METHODS: The physical, chemical, and functional stability of this formulation under different conditions of storage during 12 months and the photostability of quercetin incorporated into this system over UVB exposure for 7 days were evaluated. RESULTS: Although the results indicated a notable physical stability of the w/o microemulsions during the experimental period under all employed conditions, in both, the chemical and functional studies, a significant loss of quercetin content and antioxidant activity was found after 6 months of storage at 30°C/70% relative humidity and after 2 months at 40°C/70% relative humidity. The photostability study results demonstrated that the incorporation of quercetin into the w/o microemulsion maintained the previously demonstrated photostability of this flavonoid under forced exposure to UVB irradiation. CONCLUSION: Thus, this work demonstrates that special storage conditions (at 4 ± 2°C) are necessary to maintain the functionality of the w/o microemulsion containing quercetin and mainly emphasizes the importance of studying physical, chemical, and functional parameters at the same time during stability evaluation of active principles.


Assuntos
Antioxidantes/química , Óleos/química , Quercetina/química , Água/química , Antioxidantes/farmacologia , Química Farmacêutica , Formas de Dosagem , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Emulsões/química , Emulsões/efeitos da radiação , Umidade , Tamanho da Partícula , Quercetina/farmacologia , Temperatura , Raios Ultravioleta
19.
Chem Commun (Camb) ; 57(95): 12804-12807, 2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34783334

RESUMO

Silica is widely used in industrial applications and its performance is partially decided by its surface hydroxyl density αOH. Here we report a quick, simple liquid 1H NMR method to determine αOH using a benchtop 1H NMR spectrometer. The results show excellent agreement with the literature with an αOH range from 4.16 to 6.56 OH per nm2.

20.
J Agric Food Chem ; 69(5): 1555-1566, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33522796

RESUMO

Nicotinamide adenine dinucleotide (NAD+) plays a vital role in cellular processes that govern human health and disease. Nicotinamide phosphoribosyltransferase (NAMPT) is a rate-limiting enzyme in NAD+ biosynthesis. Thus, boosting NAD+ level via an increase in NAMPT levels is an attractive approach for countering the effects of aging and metabolic disease. This study aimed to establish IRW (Ile-Arg-Trp), a small tripeptide derived from ovotransferrin, as a booster of NAMPT levels. Treatment of muscle (L6) cells with IRW increased intracellular NAMPT protein levels (2.2-fold, p < 0.05) and boosted NAD+ (p < 0.01). Both immunoprecipitation and recombinant NAMPT assays indicated the possible NAMPT-activating ability of IRW (p < 0.01). Similarly, IRW increased NAMPT mRNA and protein levels in the liver (2.6-fold, p < 0.01) and muscle tissues (2.3-fold, p < 0.05) of C57BL/6J mice fed with a high-fat diet (HFD). A significantly increased level of circulating NAD+ was also observed following IRW treatment (4.7 fold, p < 0.0001). Dosing of Drosophila melanogaster with IRW elevated both D-NAAM (fly NAMPT) and NAD+ in vivo (p < 0.05). However, IRW treatment did not boost NAMPT levels in SIRT1 KO cells, indicating a possible SIRT1 dependency for the pharmacological effect. Overall, these data indicate that IRW is a novel small peptide booster of the NAMPT pool.


Assuntos
Citocinas/metabolismo , Nicotinamida Fosforribosiltransferase/metabolismo , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Peptídeos/administração & dosagem , Animais , Linhagem Celular , Citocinas/genética , Drosophila melanogaster , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , NAD/metabolismo , Nicotinamida Fosforribosiltransferase/genética , Obesidade/genética
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