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Clinical and experimental data from the last nine decades indicate that the preoptic area of the hypothalamus is a critical node in a brain network that controls sleep onset and homeostasis. By contrast, we recently reported that a group of glutamatergic neurons in the lateral and medial preoptic area increases wakefulness, challenging the long-standing notion in sleep neurobiology that the preoptic area is exclusively somnogenic. However, the precise role of these subcortical neurons in the control of behavioral state transitions and cortical dynamics remains unknown. Therefore, in this study, we used conditional expression of excitatory hM3Dq receptors in these preoptic glutamatergic (Vglut2+) neurons and show that their activation initiates wakefulness, decreases non-rapid eye movement (NREM) sleep, and causes a persistent suppression of rapid eye movement (REM) sleep. We also demonstrate, for the first time, that activation of these preoptic glutamatergic neurons causes a high degree of NREM sleep fragmentation, promotes state instability with frequent arousals from sleep, decreases body temperature, and shifts cortical dynamics (including oscillations, connectivity, and complexity) to a more wake-like state. We conclude that a subset of preoptic glutamatergic neurons can initiate, but not maintain, arousals from sleep, and their inactivation may be required for NREM stability and REM sleep generation. Further, these data provide novel empirical evidence supporting the hypothesis that the preoptic area causally contributes to the regulation of both sleep and wakefulness.SIGNIFICANCE STATEMENT Historically, the preoptic area of the hypothalamus has been considered a key site for sleep generation. However, emerging modeling and empirical data suggest that this region might play a dual role in sleep-wake control. We demonstrate that chemogenetic stimulation of preoptic glutamatergic neurons produces brief arousals that fragment sleep, persistently suppresses REM sleep, causes hypothermia, and shifts EEG patterns toward a "lighter" NREM sleep state. We propose that preoptic glutamatergic neurons can initiate, but not maintain, arousal from sleep and gate REM sleep generation, possibly to block REM-like intrusions during NREM-to-wake transitions. In contrast to the long-standing notion in sleep neurobiology that the preoptic area is exclusively somnogenic, we provide further evidence that preoptic neurons also generate wakefulness.
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Ácido Glutâmico/metabolismo , Hipotálamo/fisiologia , Neurônios/fisiologia , Sono REM , Vigília , Animais , Ondas Encefálicas , Hipotálamo/citologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Proteína Vesicular 2 de Transporte de Glutamato/genética , Proteína Vesicular 2 de Transporte de Glutamato/metabolismoRESUMO
INTRODUCTION: Recent studies have shown that acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) may serve as important diagnostic and therapeutic targets in sepsis. Since polymorphonuclear neutrophils (PMNs) play a pivotal role in the early phase of sepsis, we evaluated the potential therapeutic effects of cholinesterase inhibitors on PMN functions during cecal ligation and puncture- (CLP-) induced sepsis and investigated the roles of AChE and BChE as inflammatory markers under standardized experimental conditions. METHODS: Sham surgery or CLP was performed in male Wistar rats (n = 60). Animals were randomized into four groups: physostigmine, 100 µg/kg; neostigmine, 75 µg/kg; 0.9% saline (control group); and sham group, each applied four times over 24 h. The levels of reactive oxygen species (ROS) production and CD11b/CD62l expression were quantified by flow cytometry at t = 0, 6, 15, 20, and 24 h. Blood gas analysis as well as AChE and BChE activity levels was measured by validated point-of-care measurements. Clinical scores and survival times were determined. RESULTS: CLP induced a significant increase in ROS production and CD11b upregulation by rat PMNs. Treatment with physostigmine or neostigmine significantly reduced ROS production and CD11b upregulation by PMNs 20 h after CLP induction. In physostigmine-treated animals, survival times were significantly improved compared to the control animals, but not in neostigmine-treated animals. While AChE activity significantly decreased in the control animals at t > 6 h, AChE activity did not change in the sham group. BChE activity decreased at t > 20 h in the control animals. CONCLUSION: While AChE activity may serve as an acute inflammatory marker, BChE activity shows a delayed decrease. Administration of centrally acting physostigmine in CLP-induced sepsis in rats has protective effects on PMN functions and improves survival times, which may be of interest in clinical practice.
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Acetilcolinesterase/metabolismo , Biomarcadores/metabolismo , Butirilcolinesterase/metabolismo , Neostigmina/uso terapêutico , Neutrófilos/efeitos dos fármacos , Fisostigmina/uso terapêutico , Sepse/tratamento farmacológico , Sepse/metabolismo , Animais , Gasometria , Masculino , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismoRESUMO
The diffusion of ammonia in the small pore zeolite and potential commercial NH3-SCR catalyst levynite (LEV) was measured and compared with its mobility in the chabazite (CHA) topology (more established in NOx abatement catalysis), using quasielastic neutron scattering (QENS) and molecular dynamics (MD) simulations at 273, 323 and 373 K. The QENS experiments suggest that mobility in LEV is dominated by jump diffusion through the 8-ring windows between cages (as previously observed in CHA) which takes place at very similar rates in the two zeolites, yielding similar experimental self-diffusion coefficients (Ds). After confirming that the same characteristic motions are observed between the MD simulations and the QENS experiments on the picosecond scale, the simulations suggest that on the nanoscale, the diffusivity is higher by a factor of â¼2 in the CHA framework than in LEV. This difference between zeolites is primarily explained by the CHA cages having six 8-ring windows in the building unit, compared to only three such windows in the LEV cage building unit, thereby doubling the geometric opportunities to perform jump diffusion between cages (as characterised by the QENS experiments) leading to the corresponding increase in the MD calculated Ds. The techniques illustrate the importance of probing both pico- and nanoscale dynamics when studying intracrystalline diffusion in both NH3-SCR catalyst design, and in porous materials generally, where notable consistencies and differences may be found on either scale.
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PURPOSE: We previously identified small molecules that fit into a BRCA1-binding pocket within estrogen receptor-alpha (ERα), mimic the ability of BRCA1 to inhibit ERα activity ("BRCA1-mimetics"), and overcome antiestrogen resistance. One such compound, the hydrochloride salt of NSC35446 ("NSC35446.HCl"), also inhibited the growth of antiestrogen-resistant LCC9 tumor xenografts. The purpose of this study was to investigate the down-stream effects of NSC35446.HCl and its mechanism of action. METHODS: Here, we studied antiestrogen-resistant (LCC9, T47DCO, MCF-7/RR, LY2), ERα-negative (MDA-MB-231, HCC1806, MDA-MB-468), and antiestrogen-sensitive (MCF-7) cell lines. Techniques utilized include RNA-seq, qRT-PCR, cell growth analysis, cell-cycle analysis, Western blotting, luciferase reporter assays, TUNEL assays, in silico analysis of the IKKB gene, and ChIP assays. RESULTS: SC35446.HCl inhibited proliferation and induced apoptosis in antiestrogen-resistant LCC9, T47DCO, MCF-7/RR, and LY2 cells but not in ERα-negative breast cancer cell lines. IKKB (IKKß, IKBKB), an upstream activator of NF-κB, was identified as a BRCA1-mimetic-regulated gene based on an RNA-seq analysis. NSC35446.HCl inhibited IKKB, IKKA, and IKKG/NEMO mRNA and protein expression in LCC9 cells. NSC35446.HCl also inhibited NF-κB activity and expression of NF-κB target genes. In silico analysis of the IKKB promoter identified nine estrogen response element (ERE) half-sites and one ERE-like full-site. ChIP assays revealed that ERα was recruited to the ERE-like full-site and five of the nine half-sites and that ERα recruitment was inhibited by NSC35446.HCl in LCC9 and T47DCO cells. CONCLUSIONS: These studies identify functional EREs in the IKKB promoter and identify IKKB as an ERα and NSC35446.HCl-regulated gene, and they suggest that NF-κB and IKKB, which were previously linked to antiestrogen resistance, are targets for NSC35446.HCl in reversing antiestrogen resistance.
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Neoplasias da Mama/tratamento farmacológico , Antagonistas de Estrogênios/administração & dosagem , Receptor alfa de Estrogênio/genética , Quinase I-kappa B/genética , Apoptose/genética , Proteína BRCA1/antagonistas & inibidores , Proteína BRCA1/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Proliferação de Células/genética , Resistencia a Medicamentos Antineoplásicos/genética , Estrogênios/genética , Estrogênios/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Células MCF-7 , NF-kappa B/genética , Regiões Promotoras GenéticasRESUMO
INTRODUCTION: Mechanical and morphological ischemia and reperfusion (I/R) injury is reduced in septic hearts. The mechanism behind this "cardioprotection" is less well understood. As adenosine receptors play a major role for cardioprotection in non-septic hearts, we investigated the influence of adenosine receptors in a model of I/R in septic hearts. METHODS: SHAM operation or cecal ligation and puncture (CLP) was performed in adult male Wistar rats (n = 60). After 24 h of incubation, hearts were isolated and randomly assigned to a group with or without adenosine receptor (Ador) antagonists (SCH 58261 and MRS 1706) administered before reperfusion. Ischemia and reperfusion lasted for 40 min each. Cardiac function of the heart was determined by measuring left ventricular pressure (LVP). RESULTS: Before I/R, CLP hearts showed a significant mechanical left ventricular impairment (CLP: 63 ± 5 mmHg vs. SHAM: 104 ± 6 mmHg. After I/R, left ventricular function was significantly reduced in SHAM (24 ± 32 mmHg), but not in CLP hearts (65 ± 13 mmHg). mRNA expression for the AdorA2a and AdorA2b was significantly increased in CLP, but not in SHAM hearts. LVP of CLP hearts deteriorated when AdorA2a and AdorA2b were blocked. CONCLUSIONS: The morphological and functional I/R injury in septic animals is less pronounced compared to non-septic animals. By a combined blockade of AdorA2a and AdorA2b this "cardioprotective" effect is nearly abolished in septic hearts. This is the first study showing, that AdorA2a and AdorA2b may play an important role for a reduced functional I/R injury in the septic heart.
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Traumatismo por Reperfusão Miocárdica/fisiopatologia , Receptor A2A de Adenosina/fisiologia , Receptor A2B de Adenosina/fisiologia , Sepse/fisiopatologia , Antagonistas do Receptor A2 de Adenosina/farmacologia , Antagonistas do Receptor A2 de Adenosina/uso terapêutico , Animais , Cardiotônicos/farmacologia , Cardiotônicos/uso terapêutico , Circulação Coronária/efeitos dos fármacos , Coração/efeitos dos fármacos , Coração/fisiologia , Masculino , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/metabolismo , Miocárdio/metabolismo , RNA Mensageiro/metabolismo , Ratos Wistar , Receptor A2A de Adenosina/genética , Receptor A2B de Adenosina/genética , Sepse/tratamento farmacológico , Sepse/metabolismo , Função Ventricular Esquerda/efeitos dos fármacos , Pressão Ventricular/efeitos dos fármacosRESUMO
OBJECTIVES: This prospective study was designed to investigate the effect of testosterone, delivered by subcutaneous implants, on the female voice. METHODS: Ten women who had opted for testosterone therapy were recruited for voice analysis. Voices were recorded prior to treatment and at 3 months, 6 months, and 12 months while on testosterone therapy. Acoustic samples were collected with subjects reading a sentence, reading a paragraph, and participating in a conversation. Significant changes in the voice over time were investigated using a repeated-measures analysis of variance with the fundamental frequency (F0) as a response variable. Demographic variables associated with characteristics of the voice were assessed. RESULTS: There were no significant differences in average F0 related to smoking history, menopausal status, weight, or body mass index. There was no difference in average fundamental speaking frequency (sentence, paragraph, conversation) between the pre-treatment group and any post-treatment group at 3 and 12 months. There was an increase in sentence speech F0 at 6 months. Two of three patients with lower than expected F0 at baseline improved on testosterone therapy. CONCLUSION: Therapeutic levels of testosterone, delivered by subcutaneous implant, had no adverse affect on the female voice including lowering or deepening of the voice.
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Menopausa , Testosterona/efeitos adversos , Testosterona/uso terapêutico , Voz/efeitos dos fármacos , Implantes de Medicamento , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Testosterona/administração & dosagemRESUMO
BACKGROUND: Cardiovascular resuscitation upon intoxication with lipophilic ion channel-blocking agents has proven most difficult. Recently, favorable results have been reported when lipid rescue therapy is performed, i.e., the infusion of a triglyceride-rich lipid emulsion during resuscitation. However, the mechanism of action is poorly understood. METHODS: The authors investigate the effects of a clinically used lipid emulsion (Lipovenös® MCT 20%; Fresenius Kabi AG, Bad Homburg, Germany) on the block of the fast Na current (INa) induced by the lipophilic local anesthetic bupivacaine in adult rat left ventricular myocytes by using the whole cell patch clamp technique. RESULTS: Bupivacaine at 10 µm decreased INa by 54% (-19.3 ± 1.9 pApF vs. -42.3 ± 4.3 pApF; n = 17; P < 0.001; VPip = -40 mV, 1 Hz). Addition of 10% lipid emulsion in the presence of bupivacaine produced a 37% increase in INa (-26.4 ± 2.8 pApF; n = 17; P < 0.001 vs. bupivacaine alone). To test whether these results could be explained by a reduction in the free bupivacaine concentration by the lipid (lipid-sink effect), the authors removed the lipid phase from the bupivacaine-lipid mixture by ultracentrifugation. Also, the resulting water phase led to an increase in INa (+19%; n = 17; P < 0.001 vs. bupivacaine), demonstrating that part of the bupivacaine had been removed during ultracentrifugation. The substantially less lipophilic mepivacaine (40 µm) reduced INa by 27% (n = 24; P < 0.001). The mepivacaine-lipid mixture caused a significant increase in INa (+17%; n = 24; P < 0.001). For mepivacaine, only a small lipid-sink effect could be demonstrated (+8%; n = 23; P < 0.01), reflecting its poor lipid solubility. CONCLUSION: The authors demonstrate lipid rescue on the single-cell level and provide evidence for a lipid-sink mechanism.
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Anestésicos Locais/farmacologia , Bupivacaína/farmacologia , Emulsões Gordurosas Intravenosas/farmacologia , Ventrículos do Coração/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Canais de Sódio/efeitos dos fármacos , Animais , Feminino , Técnicas de Patch-Clamp/métodos , Ratos , Ratos WistarRESUMO
OBJECTIVES: Small published series suggest a higher failure rate for Angio-Seal vascular closure device (VCD) deployment after antegrade femoral puncture, despite the need for shorter haemostasis times, early discharge, and possibly higher turnover. We seek to compare the deployment efficacy and complications of the Angio-Seal VCD between antegrade and retrograde femoral arterial deployments. METHODS: Radiological data was retrospectively analysed from prospective databases from the hospitals' Computerised Radiology Information System (CRIS) over 2010-2012. Angio-Seal gauge, Rutherford class (as applicable), puncture mode (used to classify deployment as antegrade/retrograde), sheath sizes, and deployment success/failures were recorded. Numerical/statistical analyses were undertaken using Microsoft Excel 10/SISA software. RESULTS: A total of 519 Angio-Seal VIP VCDs were deployed in 470 patients over 2010-2012 (13 other patients could not be analysed due to incomplete data). Sheath sizes for antegrade/retrograde femoral puncture were 5F, n = 22/9; 6F, n = 244/223; 7F, n = 1/5; 9F, n = 4/0. 8F Angio-Seal VIPs were used for 9F punctures only, 6F for the remainder. The overall deployment success rate was 93.7%. In total, 247 (91.1%) successful antegrade deployments were undertaken with 24 (8.9%) failures, compared with 229 (96.6%) successful retrograde deployments with eight (3.4%) failures. Antegrade/retrograde failures were classed as failure to deploy, n = 15/5; bleeding despite successful deployment requiring supplementary compression, n = 6/1; haematoma formation, n = 2/1; groin pain, n = 0/1; vessel stenosis, n = 1/0. Higher deployment failures were noted with antegrade deployment (p < .02, chi-square test). CONCLUSIONS: Angio-Seal deployment is successful for both antegrade/retrograde femoral punctures albeit with a higher antegrade failure rate.
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Cateterismo Periférico/efeitos adversos , Colágeno/uso terapêutico , Artéria Femoral , Técnicas Hemostáticas , Hemostáticos/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Distribuição de Qui-Quadrado , Feminino , Artéria Femoral/diagnóstico por imagem , Técnicas Hemostáticas/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Punções , Sistemas de Informação em Radiologia , Estudos Retrospectivos , Fatores de Risco , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
INTRODUCTION: Recent data suggested an interaction between plasma constituents and the endothelial glycocalyx to be relevant for vascular barrier function. This might be negatively influenced by infusion solutions, depending on ionic composition, pH and binding properties. The present study evaluated such an influence of current artificial preparations. METHODS: Isolated guinea pig hearts were prepared in a modified Langendorff mode and perfused with Krebs-Henseleit buffer augmented with 1g% human albumin. After equilibration the perfusion was switched to replacement of one half buffer by either isotonic saline (NaCl), ringer's acetate (Ri-Ac), 6% and 10% hydroxyethyl starch (6% and 10% HES, resp.), or 4% gelatine (Gel), the artificial colloids having been prepared in balanced solution. We analysed glycocalyx shedding, functional integrity of the vascular barrier and heart performance. RESULTS: While glycocalyx shedding was not observed, diluting albumin concentration towards 0.5g% by artificial solutions was associated with a marked functional breakdown of vascular barrier competence. This effect was biggest with isotonic saline and significantly attenuated with artificial colloids, the difference in the pressure dependent transvascular fluid filtration (basal vs. during infusion in groups NaCl, Ri-Ac, 6% HES, 10% HES and Gel, n = 6 each) being 0.31 ± 0.03 vs. 1.00 ± 0.04; 0.27 ± 0.03 vs. 0.81 ± 0.03; 0.29 ± 0.03 vs. 0.68 ± 0.02; 0.32 ± 0.03 vs. 0.59 ± 0.08 and 0.31 ± 0.04 vs. 0.61 ± 0.03 g/5min, respectively. Heart performance was directly related to pH value (7.38 ± 0.06, 7.33 ± 0.03, 7.14 ± 0.04, 7.08 ± 0.04, 7.25 ± 0.03), the change in the rate pressure product being 21,702 ± 1969 vs. 21,291 ± 2,552; 22,098 ± 2,115 vs. 14,114 ± 3,386; 20,897 ± 2,083 vs. 10,671 ± 1,948; 21,822 ± 2,470 vs. 10,047 ± 2,320 and 20,955 ± 2,296 vs. 15,951 ± 2,755 mmHg × bpm, respectively. CONCLUSIONS: It appears important to maintain the pH value within a physiological range to maintain optimal myocardial contractility. Using colloids prepared in calcium-containing, balanced solutions for volume replacement therapy may attenuate the breakdown of vascular barrier competence in the critically ill.
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Fenômenos Fisiológicos Cardiovasculares/efeitos dos fármacos , Vasos Coronários/efeitos dos fármacos , Edema/tratamento farmacológico , Coração/efeitos dos fármacos , Derivados de Hidroxietil Amido/administração & dosagem , Soluções Isotônicas/administração & dosagem , Animais , Vasos Coronários/fisiologia , Soluções Cristaloides , Edema/fisiopatologia , Cobaias , Coração/fisiologia , Infusões Intravenosas , Masculino , Técnicas de Cultura de Órgãos , Distribuição AleatóriaRESUMO
BACKGROUND: The efficiency of cardiopulmonary resuscitation (CPR) training is dependent upon different influencing factors, such as the presented concepts, the participants' willingness to learn, and the interval between training sessions. However, the optimal interval for refreshing CPR training is less clear. OBJECTIVE: We evaluated the perceived need of simulator-based CPR training for nurses and correlated it with their clinical experience. METHODS: The 60 invited nurses were trained in simulator-based CPR. Knowledge about adult advanced life support was evaluated using a questionnaire after training, and participants rated their desired individual frequency of simulator-based training as well as the value of the presented training using a six-point Likert scale. The same questions were asked again after 1 year. RESULTS: All participants agreed about the usefulness of this type of simulator-based training. The average number of correct answers about typical facts in adult advanced life support showed an almost bell-shaped distribution, with the highest point at 6-15 years of clinical experience and the lowest points at≤5 and≥21 years. The desired training-frequency need was inversely correlated with clinical experience. CONCLUSIONS: There is a high interest in CPR training among nursing staff. Self-assessment about the training-frequency need was inversely correlated with clinical experience. However, the average number of correct answers on resuscitation questions decreased with clinical experience. Therefore, the training effectiveness seems to be extremely dependent on clinical experience, and therefore, training experienced senior nurses might be more challenging than training novice nurses.
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Reanimação Cardiopulmonar/educação , Competência Clínica , Reeducação Profissional , Avaliação das Necessidades , Recursos Humanos de Enfermagem Hospitalar/educação , Adulto , Feminino , Humanos , Masculino , Manequins , Pessoa de Meia-Idade , Inquéritos e Questionários , Adulto JovemRESUMO
We report on progress implementing and testing cryogenically cooled platforms for Magnetized Liner Inertial Fusion (MagLIF) experiments. Two cryogenically cooled experimental platforms were developed: an integrated platform fielded on the Z pulsed power generator that combines magnetization, laser preheat, and pulsed-power-driven fuel compression and a laser-only platform in a separate chamber that enables measurements of the laser preheat energy using shadowgraphy measurements. The laser-only experiments suggest that â¼89% ± 10% of the incident energy is coupled to the fuel in cooled targets across the energy range tested, significantly higher than previous warm experiments that achieved at most 67% coupling and in line with simulation predictions. The laser preheat configuration was applied to a cryogenically cooled integrated experiment that used a novel cryostat configuration that cooled the MagLIF liner from both ends. The integrated experiment, z3576, coupled 2.32 ± 0.25 kJ preheat energy to the fuel, the highest to-date, demonstrated excellent temperature control and nominal current delivery, and produced one of the highest pressure stagnations as determined by a Bayesian analysis of the data.
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Although exhaust gas recirculation (EGR) is an effective strategy for controlling the levels of nitrogen oxides (NO(X)) emitted from a diesel engine, the full potential of EGR in NO(X)/PM trade-off and engine performance (i.e., fuel economy) has not fully been exploited. Significant work into the cause and control of particulate matter (PM) has been made over the past decade with new cleaner fuels and after-treatment devices emerging to comply with the current and forthcoming emission regulations. In earlier work, we demonstrated that engine operation with oxygenated fuels (e.g., biodiesel) reduces the PM emissions and extends the engine tolerance to EGR before it reaches smoke-limited conditions. The same result has also been reported when high cetane number fuels such as gas-to-liquid (GTL) are used. To further our understanding of the relationship between EGR and PM formation, a diesel particulate filter (DPF) was integrated into the EGR loop to filter the recirculated soot particulates. The control of the soot recirculation penalty through filtered EGR (FEGR) resulted in a 50% engine-out soot reduction, thus showing the possibility of extending the maximum EGR limit or being able to run at the same level of EGR with an improved NO(X)/soot trade-off.
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Automóveis , Biocombustíveis/análise , Filtração , Fuligem/análise , Emissões de Veículos/análise , Tamanho da Partícula , Material Particulado/análiseRESUMO
Many people with epilepsy suffer from comorbid sleep disorders and sleep fragmentation. While the disruptive nature of seizures on sleep is well documented, it is unclear how diurnal seizures impact sleep quality and for how long these changes persist during the following nights. To better understand this relationship, the sleep architecture of two rhesus macaques were studied before and several nights after penicillin-induced diurnal seizures. These focal seizures stopped naturally, and none occurred at night. We scored sleep-stage during the nights immediately following the seizures, as well as several nights after seizure induction. We noted a significant increase in movement along with a decrease in sleep efficiency, both limited to the night of seizure induction. For both animals, we observed a significant decrease in the number of REM periods that manifested as a decrease in total REM sleep duration, and this phenomenon persisted up to 2 nights after the seizures. We also found a significant increase in the probability to transition from stage N2 to stage N1 on the night of the seizures. This study shows for the first time that the NHP model of penicillin-induced cortical seizures exhibits significant changes in sleep architecture, including an increase in nocturnal movement, change in sleep architecture and a prolonged decrease in REM activity. The prolonged decrease in REM periods compared to the temporary enhanced movement and reduction of sleep efficiency suggest that these seizures may affect two neural circuits, one controlling REM sleep entry and the other controlling nocturnal wakefulness.
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Privação do Sono , Sono REM , Animais , Eletroencefalografia , Humanos , Macaca mulatta , Convulsões/induzido quimicamente , Sono , Privação do Sono/complicações , VigíliaRESUMO
A deuterium-ice extruder has been developed for inertial confinement fusion experiments on the Sandia National Laboratories Z Facility. The screw-driven extruder is filled via desublimation, where a slow flow of deuterium gas enters the extruder cavity and freezes to the walls without entering the liquid phase. Ice generated in this manner is optically clear, demonstrating its high uniformity. When the extruder cavity is filled with ice, the screw is driven downward, closing off the gas-fill line. With the ice cavity isolated, further screw rotation compresses the deuterium through a nozzle, extruding a fiber. Fiber diameters ranging from 200 to 500 µm have been extruded to lengths of 1.5 feet before hitting the vacuum chamber floor. The fiber straightness improves with the nozzle length-to-diameter aspect ratio. Deuterium-ice fibers can persist in high vacuum for more than 10 min before breaking free from the nozzle. The peripheral infrastructure required for Z experimental operations is under development. An in-vacuum stepper-motor-based drive system will allow remote operation, and a translating cathode will ensure proper placement of the fiber in the powerflow hardware.
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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.
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BACKGROUND: Postoperative vasoplegia with minimal responsiveness to vasopressors is common after cardiac surgery. Called cardiac vasoplegic syndrome (CVS), it is caused by multiple factors. Treating CVS involves a high dose of fluids and catecholamines, however high doses of catecholamines and fluids are associated with serious side effects. There is evidence that new therapeutic strategies can lead to a reduction in norepinephrine doses and mortality in CVS. Specifically, the use of non-adrenergic vasopressors such as methylene blue (MB) can be beneficial. METHODS: We retrospectively analyzed the electronic records of 8716 adult cardiac surgery patients from November 2008 to December 2016. Medication, hemodynamic and outcome parameter data were analyzed for CVS until discharge. We determined CVS according to the following parameters: a postoperative onset of ≤24 h, a reduced mean arterial pressure (MAP) of < 70 mmHg, a dose of norepinephrine ≥0.8 mg*h- 1 and a continuously increasing need for catecholamine, without ventricular dysfunction. RESULTS: We identified 513 patients with CVS. Perioperative risk factors were higher in patients treated with methylene blue (MB). Before MB administration patients had a significantly higher dose of norepinephrine, and MAP increased after MB administration. Norepinephrine could be reduced after MB administration and MAP remained stable at the same level even after the reduction of norepinephrine. CONCLUSIONS: CVS patients have a severe systemic disease accompanied by significant operative stress and a high catecholamine requirement. The administration of MB in addition to standard treatment for CVS in the first 24 h was accompanied by an increase in MAP followed by a decrease in vasopressor requirement, indicating that early MB administration can be beneficial.
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Procedimentos Cirúrgicos Cardíacos , Vasoplegia , Idoso , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Feminino , Humanos , Masculino , Azul de Metileno , Pessoa de Meia-Idade , Estudos Retrospectivos , Volume Sistólico , Vasoplegia/tratamento farmacológico , Vasoplegia/etiologia , Função Ventricular EsquerdaRESUMO
OBJECTIVES: Surgery for acute type A aortic dissection is associated with several perioperative complications, such as acute respiratory dysfunction (ARD). The aim of this study was to investigate perioperative risk factors involved in the development of ARD and whether antibiotic treatment has an impact. METHODS: 243 patients underwent surgery for acute type A aortic dissection between 2008 and 2017. The patients were retrospectively divided into the ARD and NON-ARD group. ARD was defined as PaO2/FiO2 ≤ 200 mmHg (PF ratio) within 48 hours after surgery. All patients received either narrow- or broad-spectrum antibiotics. RESULTS: After the exclusion of 42 patients, 201 patients were analyzed. The PF ratio of the ARD group was significantly lower than of the NON-ARD group within the first 7 days. ARD patients (n = 111) were significantly older (p = .031) and had a higher body mass index (BMI) (p = .017). ARD patients required longer postoperative ventilation (2493 vs. 4695 [min], p = .006) and spent more days in the intensive care unit (7.0 vs. 8.9 [days], p = .043) compared to NON-ARD. The mortality was significantly lower for ARD than for NON-ARD patients (p = .030). The incidence of pneumonia was independent of the antibiotic treatment regime (p = .391). Renal and neurological complication rate was higher in patients treated with broad-spectrum antibiotic. CONCLUSION: ARD is the main complication (55%) that occurs approximately 24 hours after surgery for acute type A aortic dissection. The preoperative risk factors for ARD were higher age and increased BMI. Patients on broad-spectrum antibiotics did not show an improved postoperative outcome compared to patients with narrow-spectrum antibiotics.
Assuntos
Antibacterianos/uso terapêutico , Dissecção Aórtica/cirurgia , Transtornos Respiratórios/tratamento farmacológico , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/tratamento farmacológico , Complicações Pós-Operatórias/etiologia , Transtornos Respiratórios/etiologia , Estudos RetrospectivosRESUMO
Learning-activated engram neurons play a critical role in memory recall. An untested hypothesis is that these same neurons play an instructive role in offline memory consolidation. Here we show that a visually-cued fear memory is consolidated during post-conditioning sleep in mice. We then use TRAP (targeted recombination in active populations) to genetically label or optogenetically manipulate primary visual cortex (V1) neurons responsive to the visual cue. Following fear conditioning, mice respond to activation of this visual engram population in a manner similar to visual presentation of fear cues. Cue-responsive neurons are selectively reactivated in V1 during post-conditioning sleep. Mimicking visual engram reactivation optogenetically leads to increased representation of the visual cue in V1. Optogenetic inhibition of the engram population during post-conditioning sleep disrupts consolidation of fear memory. We conclude that selective sleep-associated reactivation of learning-activated sensory populations serves as a necessary instructive mechanism for memory consolidation.
Assuntos
Medo/fisiologia , Consolidação da Memória/fisiologia , Memória/fisiologia , Sono/fisiologia , Animais , Condicionamento Psicológico/fisiologia , Sinais (Psicologia) , Eletrodos , Tecnologia de Fibra Óptica , Camundongos Transgênicos , Plasticidade Neuronal/fisiologia , Neurônios/fisiologia , Optogenética , Privação do Sono/fisiopatologia , Córtex Visual/fisiopatologiaRESUMO
BACKGROUND: Today, prehospital emergency medical teams (EMTs) are confronted with emergent situations of cardiac arrest in palliative care patients. However, little is known about the out-of-hospital approach in this situation and the long-term survival rate of this specific patient type. The aim of the present investigation was to provide information about the strategic and therapeutic approach employed by EMTs in outpatient palliative care patients in cardiac arrest. METHODS: During a period of 2 years, we retrolectively analysed emergency medical calls with regard to palliative care emergency situations dealing with cardiac arrest. We evaluated the numbers of patients who were resuscitated, the prevalence of an advance directive or other end-of-life protocol, the first responder on cardiac arrest, the return of spontaneous circulation (ROSC) and the survival rate. RESULTS: Eighty-eight palliative care patients in cardiac arrest were analysed. In 19 patients (22%), no resuscitation was started. Paramedics and prehospital emergency physicians began resuscitation in 61 cases (69%) and in 8 cases (9%), respectively. A total of 10 patients (11%) showed a ROSC; none survived after 48 h. Advance directives were available in 43% of cases. The start of resuscitation was independent of the presence of an advance directive or other end-of-life protocol. CONCLUSIONS: Strategic and therapeutic approaches in outpatient palliative care patients with cardiac arrest differ depending on medical qualification. Although many of these patients do not wish to be resuscitated, resuscitation was started independent of the presence of advance directive. To reduce legal insecurity and to avoid resuscitation and a possible lengthening of the dying process, advance directives and/or "Do not attempt resuscitation" orders should be more readily available and should be adhered to more closely.
Assuntos
Reanimação Cardiopulmonar/métodos , Serviços Médicos de Emergência/métodos , Parada Cardíaca/terapia , Cuidados Paliativos/métodos , Adulto , Diretivas Antecipadas/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Feminino , Parada Cardíaca/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Ordens quanto à Conduta (Ética Médica) , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do TratamentoRESUMO
The Stroop effect is typically much larger than the reverse Stroop effect. One explanation for this asymmetry asserts that interference between the attended feature and an incongruent unattended feature depends on which feature is more strongly associated with the processing typically needed to complete the task. Accordingly, because identification of the target's color or the target word (as in the traditional Stroop paradigm) is more strongly associated with verbal processing than visual processing, the target's meaning should interfere with identification of the target's color (Stroop) more than vice versa (reverse Stroop). In contrast, localization is more strongly associated with visual processing, so strength-of-association predicts that the target's color should interfere with localizing the target word (reverse Stroop) more than vice versa (Stroop). Experiments 1 and 2 supported the strength-of-association account: compared to Stroop, the reverse Stroop effect was smaller for an identification task, but larger for a localization task. Because overall responses were slower for the reverse Stroop condition than the Stroop condition in Experiment 2, we entertained two alternative explanations for the reverse Stroop effect being larger than the Stroop effect. Experiments 3 and 4 showed that the larger reverse Stroop effect could not have been due to scaling, and Experiment 5 showed that it could not have been due to covert translation. Taken together, these experiments demonstrate the role of strength of association in generating the classic Stroop asymmetry, and pave the way for future exploration of the reverse Stroop effect using localization tasks.