Unlocking Arene Phosphorescence in Bismuth-Organic Materials.

Three novel bismuth-organic compounds, with the general formula [Bi2(HPDC)2(PDC)2]·(arene)·2H2O (H2PDC = 2,6-pyridinedicarboxylic acid; arene = pyrene, naphthalene, and azulene), that consist of neutral dinuclear Bi-pyridinedicarboxylate complexes and outer coordination sphere arene molecules were synthesized and structurally characterized. The structures of all three phases exhibit strong π-π stacking interactions between the Bi-bound PDC/HPDC and outer sphere organic molecules; these interactions effectively sandwich the arene molecules between bismuth complexes and thereby prevent molecular vibrations. Upon UV irradiation, the compounds containing pyrene and naphthalene displayed red and green emission, respectively, with quantum yields of 1.3(2) and 30.8(4)%. The emission was found to originate from the T1 → S0 transition of the corresponding arene and result in phosphorescence characteristic of the arene employed. By comparison, the azulene-containing compound displayed very weak blue-purple phosphorescence of unknown origin and is a rare example of T2 → S0 emission from azulene. The pyrene- and naphthalene-containing compounds both display radioluminescence, with intensities of 11 and 38% relative to bismuth germanate, respectively. Collectively, these results provide further insights into the structure-property relationships that underpin luminescence from Bi-based materials and highlight the utility of Bi-organic molecules in the realization of organic emission.

Association between the presence of an advanced airway and ventilation rate during pediatric CPR: A report from the Videography in Pediatric Resuscitation (VIPER) collaborative.

OBJECTIVE: To determine the association between presence of an advanced airway during pediatric cardiopulmonary resuscitation (CPR) and ventilation rates. METHODS: Prospective observational study, January 2017 to June 2020. Patients ≤18 years receiving CC for ≥2 minutes were enrolled. Ventilation rate and type of airway (advanced airway (AA), either endotracheal tube (ETT) or supraglottic airway (SGA); or natural airway (NA)) were collected from video review and analyzed in 'CPR segments' (periods of CPR by individual providers). Ventilation rate (breaths per minute, bpm) was calculated for each segment; hyperventilation was defined as >12 bpm according to 2015 American Heart Association guidelines. Univariate analysis between airway type was done by χ2 testing. Multivariate regression was used to determine the association between the presence of AA with hyperventilation while controlling for within-patient covariance. RESULTS: 779 CPR segments from 94 CPR event were analyzed. The mean ventilation rate per CPR segment across all events was 22 bpm (±16 bpm)). Mean ventilation rates were higher with AA, either ETT (24 ± 17 bpm) or SGA (34 ± 19 bpm), than with NA (17 ± 14, p < 0.001). Hyperventilation occurred more often with AA in place (ETT: 68%; SGA: 96%; NA: 43%; p < 0.001). The presence of AA was independently associated with hyperventilation (AOR 9.3, 95% CI 4.3-20.1). CONCLUSIONS: During pediatric CPR, hyperventilation occurs more often with an AA in place than during CPR with NA. Future research should focus on respiratory physiology during pediatric CPR to determine optimal ventilation rate(s) during pediatric cardiac arrest.

The effect of hand position on chest compression quality during CPR in young children: Findings from the Videography in Pediatric Resuscitation (VIPER) collaborative.

OBJECTIVE: To determine the effect of hand position on chest compression (CC) quality during CPR in young children. METHODS: Prospective observational exploratory study. Patients < 8 years receiving CC for > 2 minutes were enrolled. Data was collected from video review and CC monitor device and analyzed in 'CC segments' (periods of CC by individual providers). Four techniques were compared: two thumbs (2 T), hands encircling the chest; two fingers (2F) on the sternum; one hand on sternum (1H); two hands on sternum (2H). Univariate analysis of CC rate and depth between hand positions was performed through nonparametric testing, stratified by age category. RESULTS: 47 patients received 824 minutes of CC. Among 270 CC segments in infants < 1 yo, 2 T was used in 27%; 2F 3%; 1H 18%; 2H 26%. Among 189 CC segments in children aged 1 to 8 yo, 1H was used in 26%; 2H 74%. Across all segments, median CC rate was 117 cpm (IQR 110-125). Median depth was 2.92 cm (IQR 2.44 - 4.04) in infants < 1 yo, 3.56 cm (IQR 2.92 - 4.14) in children 1 to 8 yo. 1H achieved greater depth than 2 T in infants (p < 0.01), and 2H achieved greater depth than 1H in children > 1 (p < 0.001). CONCLUSIONS: In infants, 1H resulted in greater CC depth than 2 T. In children 1 to 8 yo, 2H resulted in greater depth than 1H.. These data suggest that different hand position during CPR in young children from what is currently recommended may result in better CPR quality.

Efficient Europium Sensitization via Low-Level Doping in a 2-D Bismuth-Organic Coordination Polymer.

A new bismuth-organic compound containing 1,10-phenanthroline (phen) and 2,5-pyridinedicarboxylic acid (PDC) was synthesized and structurally characterized by single-crystal X-ray diffraction. The structure consists of 2-D {Bi(phen)(HPDC)(PDC)}n sheets wherein the PDC ligands bridge metal centers via three unique bonding modes. The 2-D sheets are further connected through strong hydrogen-bonding interactions to form a 3-D supramolecular network. The parent compound displayed yellow photoluminescence in the solid state at room temperature. Doping studies were undertaken to incorporate Eu3+ into the structure, statistically replacing Bi3+ in small quantities (1, 5, and 10 mol % Eu3+ relative to Bi3+). All three compounds displayed characteristic Eu3+ emission, with total quantum yields as high as 16.0% and sensitization efficiencies between 0.21 and 0.37 depending on the Eu3+ doping percentage.