Prevalence and drug use correlates of inadvertent fentanyl exposure among individuals misusing drugs in seven U.S. states.

Fentanyl has emerged as the leading cause of fatal drug overdoses in the U.S. Individuals misusing drugs may not always be aware of exposure to fentanyl.To determine the prevalence of fentanyl use and extent of awareness of fentanyl exposure among a national sample of treatment-seeking individuals with opioid use disorder (n = 1098).Participants provided oral fluid and urine specimens, which were tested for drugs by liquid chromatography/tandem mass spectrometry. Participants also provided self-reports of fentanyl use.49.5% tested positive for fentanyl in oral fluid, urine, or both. Of those testing positive for fentanyl, 29.8% were unaware that they had been exposed to fentanyl. Participants testing positive for opioids methadone, and specifically 6-monoacetylmorphine (6-MAM), a unique metabolite of heroin, were significantly more likely to be unaware of fentanyl exposure than participants testing negative for these substances, with a similar trend for oxycodone and tramadol.These findings may be due to fentanyl's effect being difficult to distinguish from that of other opioids, whereas when other types of drugs are adulterated with fentanyl, the differences in effects are likely to be readily discernable. These results support the importance of expanded drug-checking services.

Time-resolved molecular dynamics of single and double hydrogen migration in ethanol.

Being the lightest, most mobile atom that exists, hydrogen plays an important role in the chemistry of hydrocarbons, proteins and peptides and most biomolecules. Hydrogen can undergo transfer, exchange and migration processes, having considerable impact on the chemical behavior of these molecules. Although much has been learned about reaction dynamics involving one hydrogen atom, less is known about those processes where two or more hydrogen atoms participate. Here we show that single and double hydrogen migrations occurring in ethanol cations and dications take place within a few hundred fs to ps, using a 3D imaging and laser pump-probe technique. For double hydrogen migration, the hydrogens are not correlated, with the second hydrogen migration promoting the breakup of the C-O bond. The probability of double hydrogen migration is quite significant, suggesting that double hydrogen migration plays a more important role than generally assumed. The conclusions are supported by state-of-the-art molecular dynamics calculations.

Probing ultrafast ππ*/nπ* internal conversion in organic chromophores via K-edge resonant absorption.

Many photoinduced processes including photosynthesis and human vision happen in organic molecules and involve coupled femtosecond dynamics of nuclei and electrons. Organic molecules with heteroatoms often possess an important excited-state relaxation channel from an optically allowed ππ* to a dark nπ* state. The ππ*/nπ* internal conversion is difficult to investigate, as most spectroscopic methods are not exclusively sensitive to changes in the excited-state electronic structure. Here, we report achieving the required sensitivity by exploiting the element and site specificity of near-edge soft X-ray absorption spectroscopy. As a hole forms in the n orbital during ππ*/nπ* internal conversion, the absorption spectrum at the heteroatom K-edge exhibits an additional resonance. We demonstrate the concept using the nucleobase thymine at the oxygen K-edge, and unambiguously show that ππ*/nπ* internal conversion takes place within (60 ± 30) fs. High-level-coupled cluster calculations confirm the method's impressive electronic structure sensitivity for excited-state investigations.Many photo-induced processes such as photosynthesis occur in organic molecules, but their femtosecond excited-state dynamics are difficult to track. Here, the authors exploit the element and site selectivity of soft X-ray absorption to sensitively follow the ultrafast ππ*/nπ* electronic relaxation of hetero-organic molecules.

A molecular symmetry analysis of the electronic states and transition dipole moments for molecules with two torsional degrees of freedom.

We present a molecular symmetry analysis of electronic states and transition dipole moments for molecules which undergo large amplitude intramolecular torsions. The method is based on the correlation between the point group of the molecule at highly symmetric configurations and the molecular symmetry group. As an example, we determine the global irreducible representations of the electronic states and transition dipole moments for the quinodimethane derivative 2-[4-(cyclopenta-2,4-dien-1-ylidene)cyclohexa-2,5-dien-1-ylidene]-2H-1,3-dioxole for which two torsional degrees of freedom can be activated upon photo-excitation and construct the resulting symmetry adapted transition dipole functions.

Hypotension after spinal anesthesia for cesarean section: identification of risk factors using an anesthesia information management system.

OBJECTIVE: To determine risk factors for developing hypotension after spinal anesthesia for cesarean section to prevent obstetric patients from hypotensive episodes potentially resulting in intrauterine malperfusion and endangering the child. METHODS: The data from 503 women, having received spinal anesthesia for cesarean sections were investigated using online gathered vital signs and specially checked manual entries employing an anesthesia information management system. Blood pressure, heart rate, and oxygen saturation were measured throughout and hypotension was defined as either a drop in mean arterial blood pressure of >20% from baseline value or readings of <90 mmHg systolic arterial blood pressure. Thirty-two variables were studied for association with hypotensive episodes using univariate analysis and logistic regression employing a forward stepwise algorithm to identify independent variables (P < 0.05). RESULTS: Hypotension was found in 284 cases (56.5%). The univariate analysis identified the neonate's weight, mother's age, body mass index, and peak sensory block height associated with hypotension. Body mass index, age and sensory block height were detected as independent factors for hypotension (odds-ratio: 1.61 each). CONCLUSIONS: Knowledge of these risk factors should increase the anesthesiologist's attention to decide for the necessity to employ prophylactic or therapeutic techniques or drugs to prevent the neonate from any risk resulting of hypotension of the mother.

Examining the influence of maternal bradycardia on neonatal outcome using automated data collection.

BACKGROUND: Due to the increasing number of caesarean sections, we investigated the influence of maternal bradycardia during general and regional anaesthesia on seven standard paediatric outcome parameters using our online recorded data. METHODS: Data from 1154 women undergoing caesarean section were investigated prospectively. Bradycardia was defined as a heart rate below 60 beats/min. The matched-pairs method was used to evaluate the impact of bradycardia on Apgar scores at 1, 5, and 10 min, umbilical artery pH and base excess, admission to paediatric intensive care unit, and seven-day mortality. Matched references were automatically selected among all patients from the data pool according to anaesthetic technique, sensory block height, urgency, maternal age and body mass index. Stepwise regression models were developed to predict the impact of intra-operative bradycardia on outcome variables with differences between matched pairs assessed using univariate analysis. RESULTS: Bradycardia was found in 146 women (12.7%) for whom a control could be matched in 131 cases (89.7%). Mean 5-minute Apgar score was 9.2+/-1.1 for study patients and 9.3+/-1.1 for controls. pH and base excess were not significantly different between groups. In cases of urgent surgery, neonates had an increased risk of 1.8 (95% CI 1.36-2.44, P<0.01) for an Apgar score