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1.
J Endocrinol Invest ; 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38724880

RESUMO

PURPOSE: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating disease characterized by persistent fatigue and decreased daily activity following physical and/or cognitive exertion. While ME/CFS affects both sexes, there is a higher prevalence in women. However, studies evaluating this sex-related bias are limited. METHODS: Circulating steroid hormones, including mineralocorticoids (aldosterone), glucocorticoids (cortisol, corticosterone, 11-deoxycortisol, cortisone), androgens (androstenedione, testosterone), and progestins (progesterone, 17α-hydroxyprogesterone), were measured in plasma samples using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Samples were obtained from mild/moderate (ME/CFSmm; females, n=20; males, n=8), severely affected patients (ME/CFSsa; females, n=24; males, n=6), and healthy controls (HC, females, n=12; males, n=17). RESULTS: After correction for multiple testing, we observed that circulating levels of 11-deoxycortisol, 17α-hydroxyprogesterone in females, and progesterone in males were significantly different between HC, ME/CFSmm, and ME/CFSsa. Comparing two independent groups, we found that female ME/CFSsa had higher levels of 11-deoxycortisol (vs. HC and ME/CFSmm) and 17α-hydroxyprogesterone (vs. HC). In addition, female ME/CFSmm showed a significant increase in progesterone levels compared to HC. In contrast, our study found that male ME/CFSmm had lower circulating levels of cortisol and corticosterone, while progesterone levels were elevated compared to HC. In addition to these univariate analyses, our correlational and multivariate approaches identified differential associations between our study groups. Also, using two-component partial least squares discriminant analysis (PLS-DA), we were able to discriminate ME/CFS from HC with an accuracy of 0.712 and 0.846 for females and males, respectively. CONCLUSION: Our findings suggest the potential value of including steroid hormones in future studies aimed at improving stratification in ME/CFS. Additionally, our results provide new perspectives to explore the clinical relevance of these differences within specific patient subgroups.

2.
Dev Sci ; 26(5): e13395, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37101383

RESUMO

Two notes separated by a doubling in frequency sound similar to humans. This "octave equivalence" is critical to perception and production of music and speech and occurs early in human development. Because it also occurs cross-culturally, a biological basis of octave equivalence has been hypothesized. Members of our team previousy suggested four human traits are at the root of this phenomenon: (1) vocal learning, (2) clear octave information in vocal harmonics, (3) differing vocal ranges, and (4) vocalizing together. Using cross-species studies, we can test how relevant these respective traits are, while controlling for enculturation effects and addressing questions of phylogeny. Common marmosets possess forms of three of the four traits, lacking differing vocal ranges. We tested 11 common marmosets by adapting an established head-turning paradigm, creating a parallel test to an important infant study. Unlike human infants, marmosets responded similarly to tones shifted by an octave or other intervals. Because previous studies with the same head-turning paradigm produced differential results to discernable acoustic stimuli in common marmosets, our results suggest that marmosets do not perceive octave equivalence. Our work suggests differing vocal ranges between adults and children and men and women and the way they are used in singing together may be critical to the development of octave equivalence. RESEARCH HIGHLIGHTS: A direct comparison of octave equivalence tests with common marmosets and human infants Marmosets show no octave equivalence Results emphasize the importance of differing vocal ranges between adults and infants.


Assuntos
Callithrix , Voz , Masculino , Adulto , Criança , Animais , Humanos , Lactente , Feminino , Fala , Som , Estimulação Acústica
3.
Anim Cogn ; 26(1): 97-116, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36574158

RESUMO

Humans are an interesting subject of study in comparative cognition. While humans have a lot of anecdotal and subjective knowledge about their own minds and behaviors, researchers tend not to study humans the way they study other species. Instead, comparisons between humans and other animals tend to be based on either assumptions about human behavior and cognition, or very different testing methods. Here we emphasize the importance of using insider knowledge about humans to form interesting research questions about animal cognition while simultaneously stepping back and treating humans like just another species as if one were an alien researcher. This perspective is extremely helpful to identify what aspects of cognitive processes may be interesting and relevant across the animal kingdom. Here we outline some examples of how this objective human-centric approach has helped us to move forward knowledge in several areas of animal acoustic cognition (rhythm, harmonicity, and vocal units). We describe how this approach works, what kind of benefits we obtain, and how it can be applied to other areas of animal cognition. While an objective human-centric approach is not useful when studying traits that do not occur in humans (e.g., magnetic spatial navigation), it can be extremely helpful when studying traits that are relevant to humans (e.g., communication). Overall, we hope to entice more people working in animal cognition to use a similar approach to maximize the benefits of being part of the animal kingdom while maintaining a detached and scientific perspective on the human species.


Assuntos
Cognição , Vocalização Animal , Humanos , Animais , Comunicação , Acústica
4.
Atten Percept Psychophys ; 84(5): 1757-1771, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35650471

RESUMO

Octave equivalence describes the perception that notes separated by a doubling in frequency sound similar. While the octave is used cross-culturally as a basis of pitch perception, experimental demonstration of the phenomenon has proved to be difficult. In past work, members of our group developed a three-range generalization paradigm that reliably demonstrated octave equivalence. In this study we replicate and expand on this previous work trying to answer three questions that help us understand the origins and potential cross-cultural significance of octave equivalence: (1) whether training with three ranges is strictly necessary or whether an easier-to-learn two-range task would be sufficient, (2) whether the task could demonstrate octave equivalence beyond neighbouring octaves, and (3) whether language skills and musical education impact the use of octave equivalence in this task. We conducted a large-sample study using variations of the original paradigm to answer these questions. Results found here suggest that the three-range discrimination task is indeed vital to demonstrating octave equivalence. In a two-range task, pitch height appears to be dominant over octave equivalence. Octave equivalence has an effect only when pitch height alone is not sufficient. Results also suggest that effects of octave equivalence are strongest between neighbouring octaves, and that tonal language and musical training have a positive effect on learning of discriminations but not on perception of octave equivalence during testing. We discuss these results considering their relevance to future research and to ongoing debates about the basis of octave equivalence perception.


Assuntos
Música , Percepção da Altura Sonora , Generalização Psicológica , Humanos , Idioma , Aprendizagem , Discriminação da Altura Tonal
5.
Micromachines (Basel) ; 13(5)2022 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-35630250

RESUMO

In this work, we present a method for growing highly c-axis oriented aluminum scandium nitride (AlScN) thin films on (100) silicon (Si), silicon dioxide (SiO2) and epitaxial polysilicon (poly-Si) substrates using a substrate independent approach. The presented method offers great advantages in applications such as piezoelectric thin-film-based surface acoustic wave devices where a metallic seed layer cannot be used. The approach relies on a thin AlN layer to establish a wurtzite nucleation layer for the growth of w-AlScN films. Both AlScN thin film and seed layer AlN are prepared by DC reactive magnetron sputtering process where a Sc concentration of 27% is used throughout this study. The crystal quality of (0002) orientation of Al0.73Sc0.27N films on all three substrates is significantly improved by introducing a 20 nm AlN seed layer. Although AlN has a smaller capacitance than AlScN, limiting the charge stored on the electrode plates, the combined piezoelectric coefficient d33,f with 500 nm AlScN is only slightly reduced by about 4.5% in the presence of the seed layer.

6.
Horm Behav ; 134: 105022, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34273676

RESUMO

The sex hormone estradiol is hypothesized to play a key role in human cognition, and reward processing specifically, via increased dopamine D1-receptor signalling. However, the effect of estradiol on reward processing in men has never been established. To fill this gap, we performed a double-blind placebo-controlled study in which men (N = 100) received either a single dose of estradiol (2 mg) or a placebo. Subjects performed a probabilistic reinforcement learning task where they had to choose between two options with varying reward probabilities to maximize monetary reward. Results showed that estradiol administration increased reward sensitivity compared to placebo. This effect was observed in subjects' choices, how much weight they assigned to their previous choices, and subjective reports about the reward probabilities. Furthermore, effects of estradiol were moderated by reward sensitivity, as measured through the BIS/BAS questionnaire. Using reinforcement learning models, we found that behavioral effects of estradiol were reflected in increased learning rates. These results demonstrate a causal role of estradiol within the framework of reinforcement learning, by enhancing reward sensitivity and learning. Furthermore, they provide preliminary evidence for dopamine-related genetic variants moderating the effect of estradiol on reward processing.


Assuntos
Estradiol , Reforço Psicológico , Dopamina , Método Duplo-Cego , Estradiol/farmacologia , Humanos , Aprendizagem , Masculino , Recompensa
7.
Anim Cogn ; 23(5): 973-987, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32572655

RESUMO

Consonant tone combinations occur naturally in the overtone series of harmonic sounds. These include sounds that many non-human animals produce to communicate. As such, non-human animals may be attracted to consonant intervals, interpreting them, e.g., as a feature of important social stimuli. There is preliminary evidence of attraction to consonance in various bird species in the wild, but few experimental studies with birds. We tested budgerigars (Melopsittacus undulatus) for attraction to consonant over dissonant intervals in two experiments. In Experiment 1, we tested humans and budgerigars using a place preference paradigm in which individuals could explore an environment with multiple sound sources. Both species were tested with consonant and dissonant versions of a previously studied piano melody, and we recorded time spent with each stimulus as a measure of attraction. Human females spent more time with consonant than dissonant stimuli in this experiment, but human males spent equal time with both consonant and dissonant stimuli. Neither male nor female budgerigars spent more time with either stimulus type. In Experiment 2, we tested budgerigars with more ecologically relevant stimuli comprised of sampled budgerigar vocalizations arranged into consonant or dissonant chords. These stimuli, however, also failed to produce any evidence of preference in budgerigar responses. We discuss these results in the context of ongoing research on the study of consonance as a potential general feature of auditory perception in animals with harmonic vocalizations, with respect to similarities and differences between human and budgerigar vocal behaviour, and future methodological directions.


Assuntos
Melopsittacus , Música , Animais , Percepção Auditiva , Feminino , Humanos , Masculino , Som
8.
Psychoneuroendocrinology ; 117: 104693, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32413673

RESUMO

Higher testosterone levels in males have previously been linked to decreased stress reactivity, but in other cases, testosterone has been reported to increase the stress response. We addressed these inconsistencies in a placebo-controlled single-dose testosterone administration study, in which 120 male participants were randomly assigned to undergo a cold-pressor test (CPT, a non-social somatic stressor), a socially evaluated cold-pressor test (SECPT, a social-somatic stressor), or a lukewarm water test (LWT, a non-stressful control condition). Throughout the experiment, blood pressure and interbeat intervals were measured continuously, and saliva samples for hormonal analyses were taken repeatedly at predefined time points. When comparing the groups treated with placebo, the SECPT elicited a larger increase in the systolic blood pressure than CPT, in agreement with previous studies. However, testosterone administration altered this pattern. Compared to placebo, testosterone increased systolic blood pressure during the CPT, whereas the opposite effect was found during the SECPT. Cortisol reactivity was not affected by testosterone administration. The CAG repeat polymorphism of the androgen receptor gene was unrelated to the effects of testosterone on the stress response, but it was correlated with blood pressure across the whole sample. Our findings demonstrate that testosterone's effects on the stress response are dependent on the social context. Testosterone's ability to flexibly influence the response to stressors may be an important mechanism through which the hormone promotes adaptive behavior. Our results are also in line with research showing that testosterone decreases social anxiety and suggest it may help to modulate the effects of stress in socially challenging situations.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Hidrocortisona/metabolismo , Comportamento Social , Estresse Psicológico/metabolismo , Estresse Psicológico/fisiopatologia , Testosterona/farmacologia , Adulto , Humanos , Masculino , Testosterona/administração & dosagem , Adulto Jovem
9.
Drug Dev Ind Pharm ; 45(9): 1523-1536, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31215822

RESUMO

The aim of this work was to investigate the mean fill weight control of a continuous capsule-filling process, whether it is possible to derive controller settings from an appendant process model. To that end, a system composed out of fully automated capsule filler and an online gravimetric scale was used to control the filled weight. This setup allows to examine challenges associated with continuous manufacturing processes, such as variations in the amount of active pharmaceutical ingredient (API) in the mixture due to fluctuations of the feeders or due to altered excipient batch qualities. Two types of controllers were investigated: a feedback control and a combination of feedback and feedforward control. Although both of those are common in the industry, determining the optimal parameter settings remains an issue. In this study, we developed a method to derive the control parameters based on process models in order to obtain optimal control for each filled product. Determined via rapid automated process development (RAPD), this method is an effective and fast way of determining control parameters. The method allowed us to optimize the weight control for three pharmaceutical excipients. By conducting experiments, we verified the feasibility of the proposed method and studied the dynamics of the controlled system. Our work provides important basic data on how capsule filler can be implemented into continuous manufacturing systems.


Assuntos
Composição de Medicamentos/métodos , Modelos Teóricos , Controle de Qualidade , Cápsulas , Composição de Medicamentos/normas , Excipientes , Estudos de Viabilidade , Pós
10.
Pharm Dev Technol ; 24(6): 775-787, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31023115

RESUMO

This paper addresses the relevance of automated content testing for the rapid automated process development (RAPD). Our previous work demonstrated that RAPD allowed a fast and efficient development of a continuous capsule-filling process. Target was the mean weight and the relative standard deviation of the weight. Likewise important are the content and the content uniformity. However, an implementation demands a certain level of automation. In general, technology is available that can detect active pharmaceutical ingredient (API) inside the capsules but the final application is linked to additional development and investment in machinery. To eliminate doubts regarding the benefits of an automated content check within the RAPD we present an application example. First, an X-ray system was used to detect barium sulfate accurately inside capsules. Second, a process was developed where barium sulfate was filled. The concentration of excipients was modified in the experiments, as well as the setting of the process parameter. The obtained model provided an explicit understanding of the process. Subsequently, the content uniformity model was compared to a model of the capsule weight relative standard deviation, confirming the benefits of an automated content check in the RAPD. Moreover, we presented another example illustrating the advantages of a connected continuous filling process, which permits evaluation of all process steps and their interactions (i.e. evaluation of the entire process).


Assuntos
Sulfato de Bário/análise , Composição de Medicamentos/métodos , Excipientes/química , Gelatina/química , Cápsulas/química , Composição de Medicamentos/economia , Radiografia/economia , Radiografia/métodos , Tecnologia Farmacêutica/economia , Tecnologia Farmacêutica/métodos , Fatores de Tempo , Raios X
11.
Int J Pharm ; 546(1-2): 154-165, 2018 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-29738798

RESUMO

This paper introduces a rapid automated process-development approach for a continuous capsule-filling process. In our proposed method, both the material attributes and the critical process parameters were varied to understand and to optimize the overall process. Using our approach a statistical process model can be generated with unprecedented speed (2 days), which is the prerequisite for effectively developing and operating continuous process platforms. In a first set of experiments a process model was developed using different mixture compositions of ascorbic acid, lactose and magnesium stearate while changing simultaneously the critical process parameters of the capsule filler (speed, pressure, immersion depth and powder bed height). Targets of the model were the mean fill weight and the relative standard deviation of the produced capsules. In a second experimental set the model was tested, i.e., the goal was to predict the behavior of the system at different set points in order to predict weight and relative standard deviation for predefined targets. Predictions were very good, thus validating our approach. The combination of the rapid automated process development approach and the continuous capsule-filling process resulted in a new strategy for the development and manufacture of pharmaceutical dosage forms.


Assuntos
Cápsulas , Composição de Medicamentos/métodos , Ácido Ascórbico/química , Lactose/química , Ácidos Esteáricos/química
12.
Drug Dev Ind Pharm ; 44(3): 502-510, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29160723

RESUMO

The aim of this paper is to explore the possibility to develop an automatically adjustable, reliable, and safe capsule filling operation. Process parameters that are critical for the tamping pin process were reviewed based on the literature and via experiment. Dosing disc height, powder bed height, machine speed, pressure on the tamping pin, and immersion depth were reviewed. Two investigations were performed on a GKF 702. In the first one, the powder feed rate onto the dosing disc was examined and modified. A distance sensor with a PID controller enabled a constant powder bed level with an online changeable set point. For a bad flowing product an improvement of the fill weight variation could be achieved by automatically adjusting the feed rate to the correct speed and matching the actual process conditions of the capsule filler. The second part of the study concerned the safety of the filler operation. Introducing a force transducer on the transfer station is a promising option for running the capsule filler safely within its process specifications. The tamping pin pressure was used to provoke different transfer forces. A deviation from a defined process specification led to a safe stop of the machine. In summary, the automated adjustment of several critical process parameters appears to be feasible and supports the rational development of efficient production processes using a dosing disc capsule filler. This is especially relevant for continuous production of pharmaceuticals.


Assuntos
Cápsulas/química , Automação/métodos , Química Farmacêutica/métodos , Pós/química , Pressão , Reprodutibilidade dos Testes , Tecnologia Farmacêutica/métodos
13.
Brain Behav Immun ; 56: 140-55, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26923630

RESUMO

Emerging evidence indicates that disruption of the gut microbial community (dysbiosis) impairs mental health. Germ-free mice and antibiotic-induced gut dysbiosis are two approaches to establish causality in gut microbiota-brain relationships. However, both models have limitations, as germ-free mice display alterations in blood-brain barrier and brain ultrastructure and antibiotics may act directly on the brain. We hypothesized that the concerns related to antibiotic-induced gut dysbiosis can only adequately be addressed if the effect of intragastric treatment of adult mice with multiple antibiotics on (i) gut microbial community, (ii) metabolite profile in the colon, (iii) circulating metabolites, (iv) expression of neuronal signaling molecules in distinct brain areas and (v) cognitive behavior is systematically investigated. Of the antibiotics used (ampicillin, bacitracin, meropenem, neomycin, vancomycin), ampicillin had some oral bioavailability but did not enter the brain. 16S rDNA sequencing confirmed antibiotic-induced microbial community disruption, and metabolomics revealed that gut dysbiosis was associated with depletion of bacteria-derived metabolites in the colon and alterations of lipid species and converted microbe-derived molecules in the plasma. Importantly, novel object recognition, but not spatial, memory was impaired in antibiotic-treated mice. This cognitive deficit was associated with brain region-specific changes in the expression of cognition-relevant signaling molecules, notably brain-derived neurotrophic factor, N-methyl-d-aspartate receptor subunit 2B, serotonin transporter and neuropeptide Y system. We conclude that circulating metabolites and the cerebral neuropeptide Y system play an important role in the cognitive impairment and dysregulation of cerebral signaling molecules due to antibiotic-induced gut dysbiosis.


Assuntos
Antibacterianos/efeitos adversos , Encéfalo/metabolismo , Disfunção Cognitiva , Colo/metabolismo , Disbiose , Microbioma Gastrointestinal/efeitos dos fármacos , Reconhecimento Psicológico , Memória Espacial , Animais , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/fisiopatologia , Modelos Animais de Doenças , Disbiose/induzido quimicamente , Disbiose/complicações , Disbiose/metabolismo , Masculino , Metabolômica , Camundongos , Camundongos Endogâmicos C57BL
14.
J Biol Chem ; 291(2): 913-23, 2016 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-26565024

RESUMO

Monoglyceride lipase (MGL) is required for efficient hydrolysis of the endocannabinoid 2-arachidonoylglyerol (2-AG) in the brain generating arachidonic acid (AA) and glycerol. This metabolic function makes MGL an interesting target for the treatment of neuroinflammation, since 2-AG exhibits anti-inflammatory properties and AA is a precursor for pro-inflammatory prostaglandins. Astrocytes are an important source of AA and 2-AG, and highly express MGL. In the present study, we dissected the distinct contribution of MGL in astrocytes on brain 2-AG and AA metabolism by generating a mouse model with genetic deletion of MGL specifically in astrocytes (MKO(GFAP)). MKO(GFAP) mice exhibit moderately increased 2-AG and reduced AA levels in brain. Minor accumulation of 2-AG in the brain of MKO(GFAP) mice does not cause cannabinoid receptor desensitization as previously observed in mice globally lacking MGL. Importantly, MKO(GFAP) mice exhibit reduced brain prostaglandin E2 and pro-inflammatory cytokine levels upon peripheral lipopolysaccharide (LPS) administration. These observations indicate that MGL-mediated degradation of 2-AG in astrocytes provides AA for prostaglandin synthesis promoting LPS-induced neuroinflammation. The beneficial effect of astrocyte-specific MGL-deficiency is not fully abrogated by the inverse cannabinoid receptor 1 agonist SR141716 (Rimonabant) suggesting that the anti-inflammatory effects are rather caused by reduced prostaglandin synthesis than by activation of cannabinoid receptors. In conclusion, our data demonstrate that MGL in astrocytes is an important regulator of 2-AG levels, AA availability, and neuroinflammation.


Assuntos
Astrócitos/enzimologia , Deleção de Genes , Inflamação/enzimologia , Inflamação/patologia , Monoacilglicerol Lipases/metabolismo , Sistema Nervoso/enzimologia , Sistema Nervoso/patologia , Animais , Ácidos Araquidônicos/metabolismo , Astrócitos/patologia , Comportamento Animal , Encéfalo/enzimologia , Citocinas/metabolismo , Endocanabinoides/metabolismo , Feminino , Proteína Glial Fibrilar Ácida/metabolismo , Glicerídeos/metabolismo , Lipopolissacarídeos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microglia/metabolismo , Microglia/patologia , Especificidade de Órgãos , Receptor CB1 de Canabinoide/metabolismo
15.
J Int Soc Sports Nutr ; 12: 40, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26500463

RESUMO

BACKGROUND: Zeolites are crystalline compounds with microporous structures of Si-tetrahedrons. In the gut, these silicates could act as adsorbents, ion-exchangers, catalysts, detergents or anti-diarrheic agents. This study evaluated whether zeolite supplementation affects biomarkers of intestinal wall permeability and parameters of oxidation and inflammation in aerobically trained individuals, and whether it could improve their performance. METHODS: In a randomized, double-blinded, placebo controlled trial, 52 endurance trained men and women, similar in body fat, non-smokers, 20-50 years, received 1.85 g of zeolite per day for 12 weeks. Stool samples for determination of intestinal wall integrity biomarkers were collected. From blood, markers of redox biology, inflammation, and DNA damage were determined at the beginning and the end of the study. In addition, VO2max and maximum performance were evaluated at baseline and after 12 weeks of treatment. For statistical analyses a 2-factor ANOVA was used. RESULTS: At baseline both groups showed slightly increased stool zonulin concentrations above normal. After 12 weeks with zeolite zonulin was significantly (p < 0.05) decreased in the supplemented group. IL-10 increased tendentially (p < 0.1) in the zeolite group. There were no significant changes observed in the other measured parameters. CONCLUSIONS: Twelve weeks of zeolite supplementation exerted beneficial effects on intestinal wall integrity as indicated via decreased concentrations of the tight junction modulator zonulin. This was accompanied by mild anti-inflammatory effects in this cohort of aerobically trained subjects. Further research is needed to explore mechanistic explanations for the observations in this study.


Assuntos
Suplementos Nutricionais , Inflamação/tratamento farmacológico , Intestinos/efeitos dos fármacos , Zeolitas/farmacologia , Adulto , Biomarcadores/sangue , Toxina da Cólera/metabolismo , Dano ao DNA , Método Duplo-Cego , Fezes/química , Feminino , Haptoglobinas , Humanos , Inflamação/sangue , Interleucina-10/sangue , Interleucina-6/sangue , Interleucina-8/sangue , Interleucinas/sangue , Masculino , Pessoa de Meia-Idade , Avaliação Nutricional , Consumo de Oxigênio , Permeabilidade , Precursores de Proteínas , Junções Íntimas/efeitos dos fármacos , Fator de Necrose Tumoral alfa/sangue , Interleucina 22
16.
Rev Sci Instrum ; 83(9): 096107, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23020434

RESUMO

We report the design, fabrication, and characterization of cantilevers with integrated AlN actuators and conductive PtSi tips for multi-frequency atomic force microscopy. These cantilevers also possess a stepped-rectangular geometry. The excellent dynamic behavior of these cantilevers is investigated using both finite-element simulations and experimental methods. Several imaging experiments are presented to illustrate the efficacy and versatility of these cantilevers.

17.
Anal Bioanal Chem ; 396(7): 2629-37, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20155414

RESUMO

Alpha-ketoglutaric acid (alpha-KG) and 5-hydroxymethylfurfural (5-HMF) are currently under investigation as promising cancer cell damaging agents. A method for the simultaneous quantitative determination of alpha-KG and 5-HMF in human plasma was established for screening these compounds in human plasma. Plasma samples were directly treated with O-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine hydrochloride to form the corresponding oximes, thus facilitating subsequent liquid-liquid extraction. After formation of the trimethylsilyl ethers, samples were analyzed by gas chromatography with electron ionization mass spectrometry. Stable isotope labeled standards were used, the preparation of (13)C(6)-5-HMF is described. Limits of quantitation were set to 0.938 microg/mL for alpha-KG and 0.156 microg/mL for 5-HMF. Inter-day accuracy was < or = 93.7% (alpha-KG) and < or = 92.8% (5-HMF). Inter-day precision was < or = 6.0% (alpha-KG) and < or = 4.6% (5-HMF). The method has been successfully applied to pharmacokinetic profiling of the compounds after intravenous application.


Assuntos
Análise Química do Sangue/métodos , Furaldeído/análogos & derivados , Cromatografia Gasosa-Espectrometria de Massas/métodos , Ácidos Cetoglutáricos/sangue , Antineoplásicos/sangue , Misturas Complexas/análise , Furaldeído/sangue , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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