Association Between In-hospital Mortality and the Institutional Factors of Intensive Care Units with a Focus on the Intensivist- to-bed Ratio: A Retrospective Cohort Study.

Purpose: To elucidate the relationship between in-hospital mortality and the institutional factors of intensive care units (ICUs), with a focus on the intensivist-to-bed ratio. Methods: A retrospective cohort study was conducted using a Japanese ICU database, including adult patients admitted between April 1, 2020 and March 31, 2021. We used a multilevel logistic regression model to investigate the associations between in-hospital mortality and the following institutional factors: the intensivist-to-bed ratios on weekdays or over weekends/holidays, different work shifts, hospital-to-ICU-bed ratio, annual-ICU-admission-to-bed ratio, type of hospital, and the presence of other medical staff. Results: The study population comprised 46 503 patients admitted to 65 ICUs. The in-hospital mortality rate was 8.1%. The median numbers of ICU beds and intensivists were 12 (interquartile range [IQR] 8-14) and 4 (IQR 2-9), respectively. In-hospital mortality decreased significantly as the intensivist-to-bed ratio at 10 am on weekdays increased: the average contrast indicated a 20% (95% confidence interval [CI]: 1%-38%) reduction when the ratio increased from 0 to 0.5, and a 38% (95% CI: 9%-67%) reduction when the ratio increased from 0 to 1. The other institutional factors did not present a significant effect. Conclusions: The intensivist-to-bed ratio at 10 am on weekdays had a significant effect on in-hospital mortality. Further investigation is needed to understand the processes leading to improved outcomes.

Fluid balance during acute phase extracorporeal cardiopulmonary resuscitation and outcomes in OHCA patients: a retrospective multicenter cohort study.

OBJECTIVE: The association between fluid balance and outcomes in patients who underwent out-of-hospital cardiac arrest (OHCA) and received extracorporeal cardiopulmonary resuscitation (ECPR) remains unknown. We aimed to examine the above relationship during the first 24 h following intensive care unit (ICU) admission. METHODS: We performed a secondary analysis of the SAVE-J II study, a retrospective multicenter study involving OHCA patients aged ≥ 18 years treated with ECPR between 2013 and 2018 and who received fluid therapy following ICU admission. Fluid balance was calculated based on intravenous fluid administration, blood transfusion, and urine output. The primary outcome was in-hospital mortality. The secondary outcomes included unfavorable outcome (cerebral performance category scores of 3-5 at discharge), acute kidney injury (AKI), and need for renal replacement therapy (RRT). RESULTS: Overall, 959 patients met our inclusion criteria. In-hospital mortality was 63.6%, and the proportion of unfavorable outcome at discharge was 82.0%. The median fluid balance in the first 24 h following ICU admission was 3673 mL. Multivariable analysis revealed that fluid balance was significantly associated with in-hospital mortality (odds ratio (OR), 1.04; 95% confidence interval (CI), 1.02-1.06; p < 0.001), unfavorable outcome (OR, 1.03; 95% CI, 1.01-1.06; p = 0.005), AKI (OR, 1.04; 95% CI, 1.02-1.05; p < 0.001), and RRT (OR, 1.05; 95% CI, 1.03-1.07; p < 0.001). CONCLUSIONS: Excessive positive fluid balance in the first day following ICU admission was associated with in-hospital mortality, unfavorable outcome, AKI, and RRT in ECPR patients. Further investigation is warranted.

Orbital hybridization of donor and acceptor to enhance the conductivity of mixed-stack complexes.

Mixed-stack complexes which comprise columns of alternating donors and acceptors are organic conductors with typically poor electrical conductivity because they are either in a neutral or highly ionic state. This indicates that conductive carriers are insufficient or are mainly localized. In this study, mixed-stack complexes that uniquely exist at the neutral-ionic boundary were synthesized by combining donors (bis(3,4-ethylenedichalcogenothiophene)) and acceptors (fluorinated tetracyanoquinodimethanes) with similar energy levels and orbital symmetry between the highest occupied molecular orbital of the donor and the lowest unoccupied molecular orbital of the acceptor. Surprisingly, the orbitals were highly hybridized in the single-crystal complexes, enhancing the room-temperature conductivity (10-4-0.1 S cm-1) of mixed-stack complexes. Specifically, the maximum conductivity was the highest reported for single-crystal mixed-stack complexes under ambient pressures. The unique electronic structures at the neutral-ionic boundary exhibited structural perturbations between their electron-itinerant and localized states, causing abrupt temperature-dependent changes in their electrical, optical, dielectric, and magnetic properties.

Emergency resuscitative thoracotomy in severe trauma: Analysis of the nation-wide registry data in Japan.

Aim: Emergency resuscitative thoracotomy is a potentially lifesaving procedure for patients with cardiac pulmonary arrest and profound circulatory failure resulting from a severe injury. However, survival rate post-emergency resuscitative thoracotomy shows considerable variation, with many studies constrained by limited sample sizes and ambiguous criteria for inclusion. Herein, we assessed the outcomes of emergency resuscitative thoracotomy and identified predictors of futility using Japan Trauma Data Bank data. Methods: Data of patients aged ≥18 years between 2004 and 2019 were analyzed. The primary outcome measure was survival at discharge. Descriptive statistics were used to compare the survivor and nonsurvivor groups. A multivariable logistic regression analysis was conducted to identify predictors of survival in patients undergoing emergency resuscitative thoracotomy while adjusting for confounding factors. Results: Among patients who underwent emergency resuscitative thoracotomy, 684/5062 (13.5%) survived. Age <65 years (adjusted odds ratio, 1.351; 95% confidence interval, 1.130-1.615; p < 0.001), absence of cardiac pulmonary arrest on emergency department arrival (adjusted odds ratio, 1.694; 95% confidence interval, 1.280-2.243; p < 0.01), Injury Severity Score <16 (adjusted odds ratio, 2.195; 95% confidence interval, 1.611-2.992; p < 0.01), and penetrating injury (adjusted odds ratio, 1.834; 95% confidence interval, 1.384-2.431; p < 0.01) were identified as factors associated with survival at discharge. Conclusion: The survival rate for emergency resuscitative thoracotomy in Japan stands at approximately 13.5%. Factors contributing to survival include younger age, absence of cardiopulmonary arrest at emergency department arrival, lack of severe trauma, and sustaining penetrating injuries.

Blood flow ratio in the gastric conduit measured by laser Doppler flowmetry: A predictor of anastomotic leakage after esophagectomy.

Background: Anastomotic leakage after esophagectomy is a common complication. Laser Doppler flowmetry (LDF) can quantitatively evaluate the blood flow in the gastric conduit. Methods: A total of 326 patients who underwent thoracoscopic/robot-assisted esophagectomy followed by gastric conduit reconstruction and end-to-side anastomosis were enrolled. We divided the gastric conduit into zones I (dominated by the right gastroepiploic vessels), II (dominated by the left gastroepiploic vessels), and III (perfused with short gastric vessels). Before pulling up the gastric conduit to the neck, LDF values were measured at the pylorus, the border between zones I and II (zone I/II), the border between zones II and III (zone II/III), and the gastric conduit tip (tip). The blood flow ratio was calculated as the LDF value divided by the LDF value at the pylorus. Results: Anastomotic leakage developed in 32 of 326 patients. Leakage was significantly associated with the blood flow ratio at the tip (p < 0.001), but not at zone I/II, zone II/III, and the anastomotic site. The receiver-operating characteristic curve analysis identified an anastomotic leakage cutoff ratio of 0.41 (at the tip). A multivariate Cox analysis showed that a blood flow ratio <0.41 at the tip was an independent risk factor for anastomotic leakage (p < 0.001). Conclusion: Anastomotic leakage after esophagectomy was significantly associated with the blood flow ratio at the tip of the gastric conduit. Preservation of the blood supply to the tip via the gastric wall might contribute to a decreased incidence of anastomotic leakage.

Synergetic binary organocatalyzed ring opening polymerization for the precision synthesis of polysiloxanes.

Organocatalytic ring-opening polymerization (ROP) is a versatile method for synthesizing well-defined polymers with controlled molecular weights, dispersities, and nonlinear macromolecular architectures. Despite spectacular advances in organocatalytic ROP, precision synthesis of polysiloxanes remains challenging due to the mismatch in polarity between highly polar initiators and nonpolar monomers and polymers and the difficulty in suppressing the formation of scrambling products via transetherification reactions during ROP of cyclic siloxanes. Here, we describe a binary organocatalytic ROP (BOROP) of hexamethylcyclotrisiloxane (D3) employing organic bases as catalysts and (thio)ureas as cocatalysts. The BOROP of D3 using triazabicyclodecene (TBD) and (thio)ureas generates polydimethylsiloxanes (PDMSs) with narrow dispersity (Mw/Mn < 1.1). Despite the similar basicities of TBD and 1,8-bis(tetramethylguanidino)naphthalene (TMGN), which is known as a proton sponge, a unitary organocatalytic system using TMGN was inactive for the ROP of D3. When the TMGN was paired with acidic urea, the BOROP of D3 yielded PDMSs with narrow dispersity (Mw/Mn < 1.1). Data suggest that the synergetic effect of TMGN and urea is results in an unprecedented activation-deactivation equilibrium between dormant and propagating species. The benefits of the present BOROP system are demonstrated by the formation of PDMS elastomers with more uniform network structures that are highly stretchy and have excellent mechanical properties.

Lower doses of carvedilol in Japanese heart failure patients with reduced ejection fraction could show the potential to be non-inferior to higher doses in US patients: An international collaborative observational study.

The Japanese national guidelines recommend significantly lower doses of carvedilol for heart failure with reduced ejection fraction (HFrEF) management than the US guidelines. Using real-world data, we determined whether initial and target doses of carvedilol in Japanese patients (JPNs) differ from those in US patients (USPs), especially in Asian Americans (ASA) and Caucasians (CA), and investigated differences in outcomes. We collected data from the electronic medical records, including demographics, carvedilol dosing, tolerability, cardiac functional indicators like EF, cardiovascular events including all-cause deaths, and laboratory values from the University of California, San Diego Health and Osaka University. JPNs had significantly lower doses (mg/day) of carvedilol initiation (66 USPs composed of 38 CAs and 28 ASAs, 17.1±16.2; 93 JPNs, 4.3±4.2, p<0.001) and one year after initiation (33.0±21.8; 11.2±6.5, p<0.001), and a significantly lower relative rate (RR) of dose discontinuation and reduction than USPs (RR: 0.406, 95% confidence interval (CI): 0.181-0.911, p<0.05). CAs showed the highest reduction rate (0.184), and ASAs had the highest discontinuation rate (0.107). A slight mean difference with narrow 95% CI ranges straddling zero was observed between the two regions in the change from the baseline of each cardiac functional indicator (LVEF, -0.68 [-5.49-4.12]; LVDd, -0.55 [-3.24-2.15]; LVDd index, -0.25 [-1.92-1.43]; LVDs, -0.03 [-3.84-3.90]; LVDs index, -0.04 [-2.38-2.30]; heart rate, 1.62 [-3.07-6.32]). The event-free survival showed no difference (p = 0.172) among the races. Conclusively, despite JPNs exhibiting markedly lower carvedilol doses, their dose effectiveness has the potential to be non-inferior to that in USPs. Dose de-escalation, not discontinuation, could be an option in some Asian and ASA HFrEF patients intolerable to high doses of carvedilol.

Importance of B-Type Natriuretic Peptide in the Detection of Patients With Structural Heart Disease in a Primary Care Setting.

BACKGROUND: Early detection and intervention for preclinical heart failure (HF) are crucial for restraining the potential increase in patients with HF. Thus, we designed and conducted a single-center retrospective cohort study to confirm the efficacy of B-type natriuretic peptide (BNP) for the early detection of preclinical HF in a primary care setting.Methods and Results: We investigated 477 patients with no prior diagnosis of HF who were under the care of general practitioners. These patients were categorized into 4 groups based on BNP concentrations: Category 1, 0 pg/mL≤BNP≤35 pg/mL; Category 2, 35 pg/mL200 pg/mL. There was a marked and statistically significant increase in the prevalence of preclinical HF with increasing BNP categories: 19.9%, 57.9%, 87.5%, and 96.0% in Categories 1, 2, 3, and 4, respectively. Compared with Category 1, the odds ratio of preclinical HF in Categories 2, 3, and 4 was determined to be 5.56 (95% confidence interval [CI] 3.57-8.67), 23.70 (95% CI 8.91-63.11), and 171.77 (95% CI 10.31-2,861.93), respectively. CONCLUSIONS: Measuring BNP is a valuable tool for the early detection of preclinical HF in primary care settings. Proactive testing in patients at high risk of HF could play a crucial role in addressing the impending HF pandemic.

Impact of stent strut link location in proximal balloon edge dilation technique for bifurcation percutaneous coronary intervention.

The single-stent strategy has generally been accepted as the default approach to bifurcation percutaneous coronary intervention. We have proposed the proximal balloon edge dilation (PBED) technique to prevent stent deformation during side branch (SB) dilation. This bench study aimed to evaluate the impact of stent link location and stent design on stent deformation, obstruction by stent struts at a jailed SB ostium, and incomplete stent apposition in the proximal optimization technique (POT)-PBED procedure. A coronary bifurcation model was used. We intentionally set the absence or presence of stent link on the carina (link-free or link-connect) under videoscope observation and compared stent parameters between 3- and 2-link stents (n = 5 each, n = 20 total). In the link-free group, the SB jailing rate of 3-link stents was significantly higher than that of 2-link stents (15.5 ± 5.1% vs. 6.6 ± 1.2%, p = 0.009). In the link-connect group, the SB jailing rate of 3-link stents was significantly lower than that of 2-link stents (30.0 ± 4.5% vs. 39.0 ± 2.6%, p = 0.009). In the bifurcation segment, the rate of incomplete stent apposition was significantly lower for 3-link stents of the link-connect group than for 2-link stents of the link-connect group (3.3 ± 4.2% vs. 19.0 ± 7.8%, p = 0.009). For both stent designs, ellipticity ratio was higher for link-connect group than link-free group. Link location as well as stent cell design greatly impacted stent deformation during the POT-PBED procedure.

Scoring System for Prediction of Left Ventricular Longitudinal Myocardial Dysfunction in Preclinical Heart Failure Patients.

BACKGROUND: Detection of left ventricular (LV) abnormalities is essential for patients with preclinical heart failure (HF) to delay progression to clinical HF. Global longitudinal strain (GLS) is a sensitive marker for the early occurrence of subtle abnormalities in LV function, but not all echocardiographic instruments can measure GLS.Methods and Results: We studied 853 preclinical HF patients to devise a scoring system for predicting low GLS (<16%). The associations of medical history and echocardiographic parameters with low GLS were evaluated using Cox proportional hazards analysis. Model 1 of the system consisted of medical history; for Model 2, conventional echocardiographic parameters were added to Model 1. For Model 1, a score ≥5 points meant prediction of low GLS with 90.2% sensitivity and 62.9% specificity (male=1 point, hypertension=4 points, dyslipidemia=1 point, atrial fibrillation=2 points, history of cardiac surgery=2 points). For Model 2, a score ≥4 points denotes prediction of low GLS with 80.3% sensitivity and 76.5% specificity (male=1 point, hypertension=2 points, atrial fibrillation=2 points, LV mass index >116 g/m2[male] or >96 g/m2[female]=1 point, LV ejection fraction <59%=2 points, E/e' >14=1 point). CONCLUSIONS: Our scoring system provides an easy-to-use evaluation of LV longitudinal myocardial dysfunction, and may prove useful for risk stratification of patients with preclinical HF.

Non-COVID-19 intensive care admissions during the pandemic: a multinational registry-based study.

BACKGROUND: The COVID-19 pandemic resulted in a large number of critical care admissions. While national reports have described the outcomes of patients with COVID-19, there is limited international data of the pandemic impact on non-COVID-19 patients requiring intensive care treatment. METHODS: We conducted an international, retrospective cohort study using 2019 and 2020 data from 11 national clinical quality registries covering 15 countries. Non-COVID-19 admissions in 2020 were compared with all admissions in 2019, prepandemic. The primary outcome was intensive care unit (ICU) mortality. Secondary outcomes included in-hospital mortality and standardised mortality ratio (SMR). Analyses were stratified by the country income level(s) of each registry. FINDINGS: Among 1 642 632 non-COVID-19 admissions, there was an increase in ICU mortality between 2019 (9.3%) and 2020 (10.4%), OR=1.15 (95% CI 1.14 to 1.17, p<0.001). Increased mortality was observed in middle-income countries (OR 1.25 95% CI 1.23 to 1.26), while mortality decreased in high-income countries (OR=0.96 95% CI 0.94 to 0.98). Hospital mortality and SMR trends for each registry were consistent with the observed ICU mortality findings. The burden of COVID-19 was highly variable, with COVID-19 ICU patient-days per bed ranging from 0.4 to 81.6 between registries. This alone did not explain the observed non-COVID-19 mortality changes. INTERPRETATION: Increased ICU mortality occurred among non-COVID-19 patients during the pandemic, driven by increased mortality in middle-income countries, while mortality decreased in high-income countries. The causes for this inequity are likely multi-factorial, but healthcare spending, policy pandemic responses, and ICU strain may play significant roles.

Testing the power-law hypothesis of the interconflict interval.

War is an extreme form of collective human behaviour characterized by coordinated violence. We show that this nature of war is substantiated in the temporal patterns of conflict occurrence that obey power law. The focal metric is the interconflict interval (ICI), the interval between the end of a conflict in a dyad (i.e. a pair of states) and the start of the subsequent conflict in the same dyad. Using elaborate statistical tests, we confirmed that ICI samples compiled from the history of interstate conflicts from 1816 to 2014 followed a power-law distribution. We then demonstrate that the power-law properties of ICIs can be explained by a hypothetical model assuming an information-theoretic formulation of the Clausewitz thesis on war: the use of force is a means of interstate communication. Our findings help us to understand the nature of wars between regular states, the significance of which has increased since the Russian invasion of Ukraine in 2022.

Detecting Magnetoelectric Effect in a Metallic Antiferromagnet via Nonreciprocal Rotation of Reflected Light.

Certain types of media breaking both space-inversion (P) and time-reversal (T) symmetries but preserving their combination PT exhibit the polarization rotation of reflected light even when that of transmitted light is prohibited. Such an effect is termed nonreciprocal rotation of reflected light (NRR). Although NRR shows nearly the same phenomenon as the magnetooptical Kerr effect or, equivalently, the Hall effect at optical frequencies, its origin is distinct and ascribed to a magnetoelectric (ME) effect at optical frequencies, i.e., the optical ME effect. Here we show the observation of NRR in a metallic antiferromagnet TbB_{4}. The result demonstrates that the ME effect in a metallic system, which is considered to be ill defined, can be detected using reflected light. Furthermore, we spatially resolve antiferromagnetic domains in TbB_{4} by microscope observations of NRR. Our work offers a unique way to probe the ME effect in metallic systems.

First-Pass Success of Video Laryngoscope Compared With Direct Laryngoscope in Intubations Performed by Residents in the Emergency Department.

BACKGROUND: The video laryngoscope (VL) has been widely used for intubation in the emergency department (ED). However, their effectiveness remains controversial, particularly among airway management performed by residents in the ED. METHODS: We aimed to examine whether the use of VL, compared to a direct laryngoscope (DL), was associated with higher first-attempt intubation success among intubations performed by residents in the ED. This is a secondary analysis of the data from a prospective, observational, multicentre study of 15 Japanese EDs from April 2012 through March 2020. We included all adult patients who underwent intubation with VL or DL by residents (postgraduate years ≤5) in the ED. The outcome measures were first-pass success and intubation-related adverse events (overall, major, and minor adverse events). To determine the association of VL use with each of the outcomes, we constructed logistic regression models with generalized estimating equations to account for patients clustering within the ED, adjusting for patient demographics, primary indications, intubation difficulty, and intubation methods. RESULTS: Of 5,261 eligible patients who underwent an initial intubation attempt by residents, 1,858 (35%) patients were attempted with VL. Intubations performed with VL had a non-significantly higher first-pass success rate than those with DL (77% vs. 64%; unadjusted odds ratio (OR)=1.20; 95% CI=0.87-1.65; P=0.27). This association was significant after adjustment for potential confounders (adjusted OR, 1.33; 95% CI, 1.06-1.67; P=0.01). As for adverse events, the use of VL was associated with a lower rate of any (adjusted OR=0.67; 95% CI=0.51-0.86; P=0.002) and minor (adjusted OR=0.69; 95% CI=0.55-0.87; P=0.002) adverse events. CONCLUSION: The use of VL was associated with a higher first-attempt success rate and a lower rate of any adverse events compared to that with DL among intubations performed by residents in the EDs.

Corrigendum: Association of airway obstruction with first-pass success and intubation-related adverse events in the emergency department: multicenter prospective observational studies.

[This corrects the article DOI: 10.3389/fmed.2023.1199750.].

Terahertz radiation by quantum interference of excitons in a one-dimensional Mott insulator.

Nearly monocyclic terahertz waves are used for investigating elementary excitations and for controlling electronic states in solids. They are usually generated via second-order optical nonlinearity by injecting a femtosecond laser pulse into a nonlinear optical crystal. In this framework, however, it is difficult to control phase and frequency of terahertz waves. Here, we show that in a one-dimensional Mott insulator of a nickel-bromine chain compound a terahertz wave is generated with high efficiency via strong electron modulations due to quantum interference between odd-parity and even-parity excitons produced by two-color femtosecond pulses. Using this method, one can control all of the phase, frequency, and amplitude of terahertz waves by adjusting the creation-time difference of two excitons with attosecond accuracy. This approach enables to evaluate the phase-relaxation time of excitons under strong electron correlations in Mott insulators. Moreover, phase- and frequency-controlled terahertz pulses are beneficial for coherent electronic-state controls with nearly monocyclic terahertz waves.

Biosynthesis and Function of VIP and Oxytocin: Mechanisms of C-terminal Amidation, Oxytocin Secretion and Transport.

In this review, we provide the status of research on vasoactive intestinal peptide (VIP) and oxytocin, typical C-terminal α-amidated peptide hormones, including their precursor protein structures, processing and C-terminal α-amidation, and the recently identified mechanisms of regulation of oxytocin secretion and its transportation through the blood brain barrier. More than half of neural and endocrine peptides, such as VIP and oxytocin, have the α-amide structure at their C-terminus, which is essential for biological activities. We have studied the synthesis and function of C-terminal α-amidated peptides, including VIP and oxytocin, since the 1980s. Human VIP mRNA encoded not only VIP but also another related C-terminal α-amidated peptide, PHM-27 (peptide having amino-terminal histidine, carboxy-terminal methionine amide, and 27 amino acid residues). The human VIP/PHM-27 gene is composed of 7 exons and regulated synergistically by cyclic AMP and protein kinase C pathways. VIP has an essential role in glycemic control using transgenic mouse technology. The peptide C-terminal α-amidation proceeded through a 2-step mechanism catalyzed by 2 different enzymes encoded in a single mRNA. In the oxytocin secretion from the hypothalamus/the posterior pituitary, the CD38-cyclic ADP-ribose signal system, which was first established in the insulin secretion from pancreatic ß cells of the islets of Langerhans, was found to be essential. A possible mechanism involving RAGE (receptor for advanced glycation end-products) of the oxytocin transportation from the blood stream into the brain through the blood-brain barrier has also been suggested.

Diaphragm Dysfunction and ICU-Acquired Weakness in Septic Shock Patients with or without Mechanical Ventilation: A Pilot Prospective Observational Study.

Sepsis is a risk factor for diaphragm dysfunction and ICU-acquired weakness (ICU-AW); however, the impact of mechanical ventilation (MV) on these relationships has not been thoroughly investigated. This study aimed to compare the incidence of diaphragm dysfunction and ICU-AW in patients with septic shock, with and without MV. We conducted a single-center prospective observational study that included consecutive patients diagnosed with septic shock admitted to the ICU between March 2021 and February 2022. Ultrasound measurements of diaphragm thickness and manual measurements of limb muscle strength were repeated after ICU admission. The incidences of diaphragm dysfunction and ICU-AW, as well as their associations with clinical outcomes, were compared between patients with MV and without MV (non-MV). Twenty-four patients (11 in the MV group and 13 in the non-MV group) were analyzed. At the final measurements in the MV group, eight patients (72.7%) had diaphragm dysfunction, and six patients (54.5%) had ICU-AW. In the non-MV group, 10 patients (76.9%) had diaphragm dysfunction, and three (23.1%) had ICU-AW. No association was found between diaphragm dysfunction and clinical outcomes. Patients with ICU-AW in the MV group had longer ICU and hospital stays. Among patients with septic shock, the incidence of diaphragm dysfunction was higher than that of ICU-AW, irrespective of the use of MV. Further studies are warranted to examine the association between diaphragm dysfunction and clinical outcomes.

Metallic State of a Mixed-Sequence Oligomer Salt That Models Doped PEDOT Family.

Modern organic conductors are typically low-molecular-weight or polymer-based materials. Low-molecular-weight materials can be characterized using crystallographic information, allowing structure-conductivity relationships to be established and conduction mechanisms to be understood. However, controlling their conductive properties through molecular structural modulation is often challenging because of their relatively narrow conjugate areas. In contrast, polymer-based materials have highly π-conjugated structures with wide molecular-weight distributions, and their structural inhomogeneity makes characterizing their structures difficult. Thus, we focused on the less-explored intermediate, i.e., single-molecular-weight oligomers that model doped poly(3,4-ethylenedioxythiophene) (PEDOT). The dimer and trimer models provided clear structures; however, the short oligomers led to much lower conductivities (<10-3 S cm-1) than that of doped PEDOT. Herein, we elongated the oligomer to a tetramer through geometrical tuning based on a mixed sequence. The "P-S-S-P" sequence (S: 3,4-ethylenedithiothiophene; P: 3,4-(2',2'-dimethypropylenedioxy)thiophene) with twisted S-S enhanced the solubility and chemical stability. The subsequent oxidation process planarized the oligomer and expanded the conjugate area. Interestingly, the sequence involving sterically bulky outer P units allowed the doped oligomer to form a pitched π-stack in the single-crystal form. This enabled the inclusion of excess counter anions, which modulated the band filling. The combined effects of conjugate area expansion and band-filling modulation significantly increased the room-temperature conductivity to 36 S cm-1. This is the highest value reported for a single-crystalline oligomer conductor. Furthermore, a metallic state was observed above room temperature in a single-crystalline oligoEDOT for the first time. This unique mixed-sequence strategy for oligomer-based conductors enabled the precise control of conductive properties.

Association of airway obstruction with first-pass success and intubation-related adverse events in the emergency department: multicenter prospective observational studies.

Background: Airway obstruction is a relatively rare but critical condition that requires urgent intervention in the emergency department (ED). The present study aimed to investigate the association of airway obstruction with first-pass success and intubation-related adverse events in the ED. Methods: We analyzed data from two prospective multicenter observational studies of ED airway management. We included adults (aged ≥18 years) who underwent tracheal intubation for non-trauma indications from 2012 through 2021 (113-month period). Outcome measures were first-pass success and intubation-related adverse events. We constructed a multivariable logistic regression model adjusting for age, sex, modified LEMON score (without airway obstruction), intubation methods, intubation devices, bougie use, intubator's specialty, and ED visit year with accounting for patients clustering within the ED. Results: Of 7,349 eligible patients, 272 (4%) underwent tracheal intubation for airway obstruction. Overall, 74% of patients had first-pass success and 16% had intubation-related adverse events. The airway obstruction group had a lower first-pass success rate (63% vs. 74%; unadjusted odds ratio [OR], 0.63; 95% CI, 0.49-0.80), compared to the non-airway obstruction group. This association remained significant in the multivariable analysis (adjusted OR 0.60, 95%CI 0.46-0.80). The airway obstruction group also had a significantly higher risk of adverse events (28% vs. 16%; unadjusted OR, 1.93; 95% CI, 1.48-2.56, adjusted OR, 1.70; 95% CI, 1.27-2.29). In the sensitivity analysis using multiple imputation, the results remained consistent with the main results: the airway obstruction group had a significantly lower first-pass success rate (adjusted OR, 0.60; 95% CI, 0.48-0.76). Conclusion: Based on these multicenter prospective data, airway obstruction was associated with a significantly lower first-pass success rate and a higher intubation-related adverse event rate in the ED.