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1.
Opt Express ; 29(22): 36487-36502, 2021 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-34809059

RESUMEN

Laser cutting is a materials processing technique used throughout academia and industry. However, defects such as striations can be formed while cutting, which can negatively affect the final quality of the cut. As the light-matter interactions that occur during laser machining are highly non-linear and difficult to model mathematically, there is interest in developing novel simulation methods for studying these interactions. Deep learning enables a data-driven approach to the modelling of complex systems. Here, we show that deep learning can be used to determine the scanning speed used for laser cutting, directly from microscope images of the cut surface. Furthermore, we demonstrate that a trained neural network can generate realistic predictions of the visual appearance of the laser cut surface, and hence can be used as a predictive visualisation tool.

2.
Sleep ; 43(4)2020 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-31626696

RESUMEN

OBJECTIVES: To evaluate the human abuse potential of pitolisant, a selective histamine 3 (H3)-receptor antagonist/inverse agonist recently approved by the US Food and Drug Administration for the treatment of excessive daytime sleepiness in adult patients with narcolepsy. METHODS: Nondependent, recreational stimulant users able to distinguish phentermine HCl 60 mg from placebo in a drug discrimination test were randomized in a four-period, double-blind, crossover design to receive single doses of pitolisant 35.6 mg (therapeutic dose), pitolisant 213.6 mg (supratherapeutic dose), phentermine HCl 60 mg, and placebo. The primary endpoint was maximum effect (Emax) on the 100-point Drug Liking ("at this moment") visual analog scale. RESULTS: In 38 study completers (73.7% male; 65.8% white; mean age, 33.3 years), mean Drug Liking Emax was significantly greater for phentermine versus pitolisant 35.6 mg (mean difference, 21.4; p < 0.0001) and pitolisant 213.6 mg (mean difference, 19.7; p < 0.0001). Drug Liking Emax was similar for pitolisant (both doses) and placebo. Similarly, for key secondary measures of Overall Drug Liking and willingness to Take Drug Again, mean Emax scores were significantly greater for phentermine versus pitolisant (both doses) and similar for pitolisant (both doses) versus placebo. The incidence of adverse events was 82.1% after phentermine HCl 60 mg, 72.5% after pitolisant 213.6 mg, 47.5% after pitolisant 35.6 mg, and 48.8% after placebo administration. CONCLUSIONS: In this study, pitolisant demonstrated significantly lower potential for abuse compared with phentermine and an overall profile similar to placebo; this suggests a low risk of abuse for pitolisant. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT03152123. Determination of the abuse potential of pitolisant in healthy, nondependent recreational stimulant users. https://clinicaltrials.gov/ct2/show/NCT03152123.


Asunto(s)
Cataplejía , Narcolepsia , Adulto , Cataplejía/inducido químicamente , Cataplejía/tratamiento farmacológico , Estudios Cruzados , Método Doble Ciego , Femenino , Agonistas de los Receptores Histamínicos/efectos adversos , Humanos , Masculino , Narcolepsia/tratamiento farmacológico , Piperidinas/efectos adversos
3.
J Phys Chem A ; 123(29): 6269-6280, 2019 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-31298545

RESUMEN

The 4H-pyran-4-one (4PN) molecule serves as a model for investigating structural changes following π* ← n electronic excitation. We have recorded the cavity ringdown (CRD) absorption spectrum of 4PN vapor at room temperature, over the wavelength region from 350 to 370 nm. This spectral region includes the T1(n,π*) ← S0 band system as well as the low-energy portion of the S1(n,π*) ← S0 system. Aided by predictions from ab initio (equation-of-motion excitation energies with dynamical correlation incorporated at the level of coupled cluster singles doubles, EOM-EE-CCSD) and density functional theory (time-dependent density functional theory with PBE0 functional, TDPBE0) calculations, we have made vibronic assignments for about 30 features in the CRD spectrum, mostly T1(n,π*) ← S0 transitions. We have used these results to correct certain vibronic assignments appearing in the previous literature for both T1(n,π*) ← S0 and S1(n,π*) ← S0 band systems. We conclude that the lowest-energy carbonyl wagging fundamentals (ν27, in-plane and ν17, out-of-plane) undergo significant frequency drops (28 and 50%, respectively) upon T1(n,π*) ← S0 excitation and similar drops (29 and 39%, respectively) for S1(n,π*) ← S0 excitation. We find that vibrational modes involving the conjugated ring atoms undergo relatively small frequency changes upon π* ← n excitation, for both T1 and S1 states. We have used the present spectroscopic results and vibronic assignments to test the accuracy of computed excited-state frequencies for 4PN. This benchmarking process shows that the economical time-dependent density functional theory method is impressively accurate for certain (but not all) vibrational modes. The highly correlated EOM-EE-CCSD ab initio method is capable of making accurate frequency predictions, but the results, unexpectedly, depend sensitively on basis set family. This anomaly is traceable to a computed conical intersection between the T1(n,π*) and T2(π,π*) surfaces near the T1(n,π*) potential minimum. Relatively small errors in the location of the conical intersection lead to enhanced mixing of the two electronic states and incorrect T1(n,π*) vibrational frequencies when certain triple-ζ quality basis sets are used.

4.
J Clin Psychopharmacol ; 39(3): 226-237, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30939592

RESUMEN

PURPOSE/BACKGROUND: N-methyl-D-aspartate (NMDA) receptor (NMDAR) antagonists are potential agents for the treatment of several central nervous system disorders including major depressive disorder. Racemic methadone, L-methadone, and D-methadone all bind the NMDAR with an affinity similar to that of established NMDAR antagonists, whereas only L-methadone and racemic methadone bind to opioid receptors with high affinity. Therefore, D-methadone is expected to have no clinically significant opioid effects at therapeutic doses mediated by its NMDAR antagonism. METHODS: We conducted 2 phase 1, double-blind, randomized, placebo-controlled, single- and multiple-ascending-dose studies to investigate the safety and tolerability of oral D-methadone and to characterize its pharmacokinetic profile in healthy opioid-naive volunteers. RESULTS: D-Methadone exhibits linear pharmacokinetics with dose proportionality for most single-dose and multiple-dose parameters. Single doses up to 150 mg and daily doses up to 75 mg for 10 days were well tolerated with mostly mild treatment-emergent adverse events and no severe or serious adverse events. Dose-related somnolence and nausea occurred and were mostly present at the higher dose level. There was no evidence of respiratory depression, dissociative and psychotomimetic effects, or withdrawal signs and symptoms upon abrupt discontinuation. An overall dose-response effect was observed, with higher doses resulting in larger QTcF (QT interval corrected using Fridericia formula) changes from baseline, but none of the changes were considered clinically significant by the investigators. Mild, dose-dependent pupillary constriction of brief duration occurred particularly at the 60-mg dose or above in the single-ascending-dose study and at the dose of 75 mg in the multiple-ascending-dose study. No detectable conversion of D-methadone to L-methadone occurred in vivo. CONCLUSIONS: These results support the safety and continued clinical development of D-methadone as an NMDAR antagonist for the treatment of depression and other central nervous system disorders.


Asunto(s)
Analgésicos no Narcóticos/administración & dosificación , Metadona/administración & dosificación , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Adulto , Analgésicos no Narcóticos/efectos adversos , Analgésicos no Narcóticos/farmacocinética , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Femenino , Humanos , Masculino , Metadona/efectos adversos , Metadona/farmacocinética , Persona de Mediana Edad , Adulto Joven
5.
J Phys Chem A ; 121(12): 2343-2352, 2017 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-28260378

RESUMEN

The 2-cyclohexen-1-one (2CHO) molecule serves as a prototype for understanding the photochemical properties of conjugated enones. We have recorded the cavity ringdown (CRD) absorption spectrum of 2CHO vapor at room temperature over the 360-380 nm range. This portion of the spectrum encompasses the S1(n,π*) ← S0 vibronic band system in the region of the C═C and C═O stretch fundamentals. We have assigned about 40 vibronically resolved features in the spectrum, affording fundamental frequencies for 7 different vibrational modes in the S1(n,π*) state, including the C═C (1554 cm-1) and OC-CH (1449 cm-1) stretch modes. The C═O stretch character is spread over at least four different vibrational modes in the S1(n,π*) state, with fundamentals spanning the 1340-1430 cm-1 interval. This finding stems from a significant reduction in C═O bond order upon excitation, which leads to near-coincidence of the C═O stretch and several CH2 wag frequencies. Such complexities make 2CHO an ideal candidate for testing excited-state computational methods. We have used the present spectroscopic results to test EOM-EE-CCSD harmonic-frequency predictions for the S1(n,π*) state. We have also benchmarked the performance of less costly computational methods, including CIS(D) and TDDFT. For certain density functionals (e.g., B3LYP and PBE0), we find that the accuracy of TDDFT frequency predictions can approach but not meet that of EOM-EE-CCSD.

6.
PLoS One ; 8(11): e77057, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24244272

RESUMEN

BACKGROUND: Emergency department discharge instructions are variably understood by patients, and in the setting of emergency department crowding, innovations are needed to counteract shortened interaction times with the physician. We evaluated the effect of viewing an online video of diagnosis-specific discharge instructions on patient comprehension and recall of instructions. METHODS: In this prospective, single-center, randomized controlled trial conducted between November 2011 and January 2012, we randomized emergency department patients who were discharged with one of 38 diagnoses to either view (after they left the emergency department) a vetted online video of diagnosis-specific discharge instructions, or to usual care. Patients were subsequently contacted by telephone and asked three standardized questions about their discharge instructions; one point was awarded for each correct answer. Using an intention-to-treat analysis, differences between groups were assessed using univariate testing, and with logistic regression that accounted for clustering on managing physician. A secondary outcome measure was patient satisfaction with the videos, on a 10-point scale. RESULTS: Among 133 patients enrolled, mean age was 46.1 (s.d.D. 21.5) and 55% were female. Patients in the video group had 19% higher mean scores (2.5, s.d. 0.7) than patients in the control group (2.1, s.d. 0.8) (p=0.002). After adjustment for patient age, sex, first language, triage acuity score, and clustering, the odds of achieving a fully correct score (3 out of 3) were 3.5 (95% CI, 1.7 to 7.2) times higher in the video group, compared to the control group. Among those who viewed the videos, median rating of the videos was 10 (IQR 8 to 10). CONCLUSIONS: In this single-center trial, patients who viewed an online video of their discharge instructions scored higher on their understanding of key concepts around their diagnosis and subsequent care. Those who viewed the videos found them to be a helpful addition to standard care. TRIAL REGISTRATION: ClinicalTrials.gov NCT01361932 http://clinicaltrials.gov/ct2/show/NCT01361932?term=nct01361932&rank=1.


Asunto(s)
Servicio de Urgencia en Hospital , Internet , Alta del Paciente , Satisfacción del Paciente , Grabación en Video , Femenino , Humanos , Masculino
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