bluuebunny/crossref_metadata_2025 huggingface dataset:
Degradation and Metabolite Production of Tylosin in Anaerobic and Aerobic Swine‐Manure Lagoons
Authors: Kolz A. C. , Moorman T. B. , Ong S. K. , Scoggin K. D. , Douglass E. A.
Published: October 2005

Watershed contamination from antibiotics is becoming a critical issue because of increased numbers of confined animal‐feeding operations and the use of antibiotics in animal production. To understand the fate of tylosin in manure before it is land‐applied, degradation in manure lagoon slurries at 22°C was studied. Tylosin disappearance followed a biphasic pattern, where rapid initial loss was followed by a slow removal phase. The 90% disappearance times for tylosin, relomycin (tylosin D), and desmycosin (tylosin B) in anaerobically incubated slurries were 30 to 130 hours. Aerating the slurries reduced the 90% disappearance times to between 12 and 26 hours. Biodegradation and abiotic degradation occur, but strong sorption to slurry solids was probably the primary mechanism of tylosin disappearance. Dihydrodesmycosin and an unknown degradate with molecular mass of m/z 934.5 were detected. Residual tylosin remained in slurry after eight months of incubation, indicating that degradation in lagoons is incomplete and that residues will enter agricultural fields.
Prediction of the Bioconcentration Factor of PCBs in Fish Using the Molecular Connectivity Index and Fragment Constant Models
Authors: Hu Haiying , Xu Fuliu , Li Bengang , Cao Jun , Dawson R. , Tao Shu
Published: October 2005

Models based on molecular connectivity index (MCI) and fragment constant (FC) method were developed for prediction of the bioconcentration factor (BCF) for polychlorobiphenyls (PCBs) in fish. The mean residuals for the MCI and FC models were 0.195 and 0.223 log units, respectively. The two models were then compared in terms of their mean residuals. In addition to the chlorine atom substitution number, other important structural features exhibiting a significant influence on the BCFs of PCB congeners were discussed and incorporated to the models. These features include the degree of the ortho‐substitution, the presence of chlorine pairs in the three‐ and five‐ positions, and the crowding of chlorine atoms on the phenyl ring.
Simultaneous Nitrification–Denitrification and Clarification in a Pseudoliquified Activated Sludge System
Authors: Nakhla George F. , Lugowski Andrew , Sverdlikov Anatoly , Scherbina Gennadij , Babcock Ken
Published: October 2005

This paper describes results from a pilot study of a novel wastewater treatment technology, which incorporates nutrient removal and solids separation to a single step. The pseudoliquified activated sludge process pilot system was tested on grit removal effluent at flowrates of 29.4 to 54.7 m3/d, three different solid residence times (SRT) (15, 37, and 57 days), and over a temperature range of 12 to 28°C. Despite wide fluctuations in the influent characteristics, the system performed reliably and consistently with respect to organics and total suspended solids (TSS) removals, achieving biochemical oxygen demand (BOD) and TSS reductions of >96% and approximately 90%, respectively, with BOD5 and TSS concentrations as low as 3 mg/L. Although the system achieved average effluent ammonia concentrations of 2.7 to 3.2 mg/L, nitrification efficiency appeared to be hampered at low temperatures (<15°C). The system achieved tertiary effluent quality with denitrification efficiencies of 90 and 91% total nitrogen removal efficiency at a total hydraulic retention time of 4.8 hours and an SRT of 12 to 17 days. With ferric chloride addition, effluent phosphorous concentrations of 0.5 to 0.8 mg/L were achieved. Furthermore, because of operation at high biomass concentrations and relatively long biological SRTs, sludge yields were over 50% below typical values for activated sludge plants. The process was modeled using activated sludge model No. 2, as a two‐stage system comprised an aerobic activated sludge system followed by an anoxic system. Model predictions for soluble BOD, ammonia, nitrates, and orthophosphates agreed well with experimental data.
Effect of Bubble‐Induced Surface Turbulence on Gas–Liquid Mass Transfer in Diffused Aeration Systems
Authors: Monteith H. D. , Bell J. P. , Parker W. J. , Melcer H. , Harvey R. T.
Published: October 2005

Models that predict volatilization of organic compounds from wastewater treatment basins may underestimate emission rates if the surfaces are considered as quiescent. In reality, the water surface may be agitated by subsurface aeration, increasing mass transfer across the tank surface air–water interface. This study investigated the effect of turbulence, induced by diffused bubble aeration, on mass transfer at the water surface of a pilot aeration basin. The mass transfer of ammonia from an enclosed headspace over the basin to acidified water was measured when different diffuser types and airflow rates were applied. Oxygen‐transfer tests were conducted immediately following each ammonia‐transfer test. Increasing airflow rates through fine‐ and coarse‐bubble diffusers had a significant effect on the ammonia mass‐transfer rate. Experimental mass‐transfer parameters (KLa's) for surface volatilization derived with aeration present were up to 48% higher than the KLa values for quiescent conditions over the range of conditions tested. No effect of diffuser type on ammonia transfer could be determined. The study results infer an effect on oxygen transfer into the water at the surface and potential transfer of volatile organic compounds, if present, from the water. The results of the ammonia mass‐transfer experiments suggest that adjustments to the existing mass transfer correlations for surface volatilization from aeration basins may be in order. Such adjustments will have the greatest effect on predictions for the less volatile compounds, under conditions of low airflow rates.
Retention of Chromium (VI) on a Macroporous Char Following ChemChar Gasification and Successive Leaching with Water and Acids
Authors: Marrero Thomas W. , Manahan Stanley E.
Published: October 2005

A granular macroporous char, triple‐reverse‐burn (TRB) char, was loaded with 23.40 mg Cr/g TRB char from an aqueous solution, and the retained metal was leached by water, 0.66 M nitric acid, concentrated nitric acid, and concentrated hydrochloric acid before and after treatment by a reductive thermal gasification process (ChemChar process developed by ChemChar Research, Inc., Columbia, Missouri). The chromium leachate was analyzed by flame atomic adsorption. Reverse‐ and forward‐mode gasifications were performed on the metal‐laden char. With the exception of a 10% mass loss of carbon, the reverse mode gasification process does not change the physical characteristics of the granular char, but does increase the retention of the chromium from 16.7 to 24.2%, depending on the leachant. The forward mode gasification process produces a vitrified (or glasslike) ash residue. There was an 11.6 to 13.1% increase in the retention of the chromium by the slag and ash when compared to the nongasified chromium‐loaded TRB char. Chromium (VI) was effectively removed from solution by TRB char and found to be retained to a higher degree on the char after a reductive thermal treatment.
Biogeochemical Analysis of Hydrogen Sulfide Removal by a Lava‐Rock Packed Biofilter
Authors: Li Hebi , Lueking Donald R. , Mihelcic James R. , Peterson Karl
Published: October 2005

Although lava‐rock‐based biofilters have demonstrated their efficiencies for hydrogen sulfide (H2S) removal found in odorous air emissions, the biogeochemical basis for this removal is unclear. In this study, samples of lava rock and rinse water from biofilters at Cedar Rapids Water Pollution Control Facilities (Iowa) were used to study the structure and chemical composition of lava rock and to identify the predominant microorganism(s) present in lava‐rock‐based biofilters. It was found that iron, in the form of Fe2+ and Fe3+, was present in lava rock. Although literature suggests that Acidithiobacillus thiooxidans are primarily responsible for gaseous H2S removal in biofilters, our study showed that Acidithiobacillus ferrooxidans was the dominant microorganism in the lava‐rock‐based biofilters. A novel mechanism for H2S removal in a lava‐rock‐based biofilter is proposed based on the biogeochemical analysis of lava rock.
Inhibition of Sulfide Generation in a Reclaimed Wastewater Pipe by Nitrate Dosage and Denitrification Kinetics
Authors: Rodríguez‐Gómez Luis E. , Delgado Sebastián , Álvarez Manuel , Elmaleh Samuel
Published: October 2005

Sulfide generation should be avoided during wastewater transportation. The efficiency of nitrate dosing for the inhibition of sulfide generation was evaluated during reclaimed wastewater transport with two nitrate doses, 2.5 and 5 mg/L nitrate‐nitrogen (NO3‐N). A calcium nitrate [Ca(NO3)2] solution was injected at the beginning of the 61‐km‐long gravity pipe, which is part of the Reclaimed Wastewater Reuse System of South Tenerife (Spain). During transportation, after dissolved oxygen depletion, a denitrification process took place. With the 5 mg/L NO3‐N dose, nitrate was not completely removed at the end of the pipe, whereas with 2.5 mg/L NO3‐N, a complete denitrification was achieved. Sulfide generation was completely inhibited with the 5 mg/L dose. However, with 2.5 mg/L, sulfide generation was not completely inhibited but delayed and minimized to a great extent. Denitrification was stoichiometrically limited by the availability in biodegradable matter. An empirical equation enables one to predict the nitrate concentration.
Selective Extraction of Trace Mercury and Cadmium from Drinking Water Sources
Authors: Zhao Xuan , Zhao Gang , Wang Jianlong , Yun Guichun
Published: October 2005

In this paper, a new alternative method, i.e., selective extraction by weakly basic anion exchange resin, has been developed for the removal of trace cadmium and mercury ions from drinking water sources. The mechanism of heavy metal removal is based on selective extraction as the results of LEWIS‐base–acid interactions. Transfer of trace mercury species from liquid to resin phase coincides well with the performance of film diffusion. The results demonstrated that the presence of chlorine has a negligible influence on the removal of mercury. However, humic acids can strongly bind mercury by the formation of complex compounds and therefore become the obstacle in the diffusion progress. At neutral or base pH, the resin material exhibits the favorable uptake of heavy metals. In filter experiments, the studied resin material offers favorable properties in the selective extraction of trace mercury and cadmium.
Application of Anaerobic and Aerobic Activated Sludge to Phosphorus‐Deficient Wastewater Treatment
Authors: Harper W. F. , Jenkins D.
Published: October 2005

Anaerobic and aerobic (AnA) and completely aerobic (CA) sequencing‐batch reactors (SBRs) were used to investigate the suitability of the AnA process for treating phosphorus (P)‐deficient wastewaters with highly variable influent chemical oxygen demand (COD) loading. Both SBRs were subjected to influent COD loading patterns (LPs) that simulated (1) daily COD loading fluctuations, (2) weekend shutdowns, and (3) long weekend or holiday shutdowns. During LP 1, the AnA SBR produced lower average effluent soluble phosphorus concentrations than CA SBR (0.4 vs. 1.0 mgP/L). A similar result was observed during LP 2, but effluent acetate was detected after the first high COD loading cycle of the weekday loading period. During LP 3, the volatile suspended solids content of both reactors dropped sharply, and the effluent quality of both SBRs deteriorated. Model predictions suggest that the AnA process is stable when treating LP 1, but eventually fails when treating LP 2.
Formation and Biodegradation of Toluene in the Anaerobic Sludge Digestion Process
Authors: Mrowiec Boz˙ena , Suschka Jan , Keener Tim C.
Published: October 2005

The formation of toluene in municipal anaerobic primary and secondary sludge digestion processes was investigated. Experiments were carried out in a large laboratory‐scale reactor using sludge from a primary settling tank of a municipal treatment plant. It was found that toluene was produced in the supernatant in relatively large concentrations for almost all cases tested. The concentration of toluene varied and was found to depend on the stage of the anaerobic process. During the acidity phase, which is the first stage of anaerobic digestion, an increase of toluene concentration was observed, while in the transition period, from the acidity phase to methanogenesis, the toluene concentration decreased. It was concluded that biosynthesis of toluene occurs in the acidogenic phase, while biodegradation was prevalent in the methanogenic stage. Depending on the type of experiments, an increase of toluene from a base value of approximately 200 μg/L up to 20 000 and 42 000 μg/L was measured in the first stage of anaerobic digestion. In the subsequent methane‐production stage of digestion, the estimated rate of toluene decrease (biodegradation) varied from 400 to 900 μg/L‐d.
Uncertainty Analysis in QUAL2E Model of Zayandeh‐Rood River
Authors: Abrishamchi A. , Tajrishy M. , Shafieian P.
Published: October 2005

Water‐quality modeling and prediction is a complicated task because of inherent randomness and uncertainties associated with various processes and variables throughout the stream environment and the lack of appropriate data. Hence, the results of mathematical models are always approximate, lying within an uncertainty. This paper describes and demonstrates the application of the U.S. Environmental Protection Agency's water‐quality model, QUAL2E‐UNCAS, to the Zayandeh‐Rood River in Iran. First‐order reliability analysis is used to examine the variability of predicted water‐quality parameters of total dissolved solids, dissolved oxygen, and biochemical oxygen demand. This analysis also determines key sources of uncertainty affecting prediction of the water‐quality parameters. The results show that reliability analysis can help water‐quality modelers and planners to quantify the reliability of the water‐quality predictions and to carry out more efficiently planned sampling and data collection programs to reduce model‐prediction uncertainty.
Integrating Decay, Storage, Kinetic Selection, and Filamentous Backbone Factors in a Bacterial Competition Model
Authors: Lou In Chio , de los Reyes Francis L.
Published: October 2005

Filamentous bulking in activated sludge systems occurs when filamentous organisms outgrow floc‐forming bacteria and interfere with sludge settling. The competition between filaments and floc formers has been described previously using the kinetic selection and filamentous backbone theories. We hypothesized that differences in decay rates and storage abilities also affect this competition. We tested this hypothesis by integrating these four factors into a substrate‐utilization model to predict and explain coexistence in a completely mixed reactor. In addition, filamentous and nonfilamentous sludges were developed in laboratory‐scale reactors and analyzed to determine decay rates. The modeling results showed coexistence of the two organism types, and sensitivity analysis showed that the kinetic parameters, storage rate constants, and backbone coefficient had the greatest effect on the simulation results. Monte Carlo simulation showed the effect of storage, and the ranges of dilution rates wherein one group outcompeted the other were delineated.
Anaerobic Biodegradation of Methyl tert‐Butyl Ether Under Iron‐Reducing Conditions in Batch and Continuous‐Flow Cultures
Authors: Pruden Amy , Sedran Marie A. , Suidan Makram T. , Venosa Albert D.
Published: October 2005

The feasibility of biodegradation of the fuel oxygenate methyl tert‐butyl ether (MTBE) under iron‐reducing conditions was explored in batch and continuous‐flow systems. A porous pot completely‐mixed reactor was seeded with diverse cultures and operated under iron‐reducing conditions. For batch studies, culture from the reactor was transferred anaerobically to serum bottles containing either MTBE alone or MTBE with ethanol (EtOH) and excess electron acceptor. In the continuous‐flow reactor, MTBE conversion to tert‐butyl alcohol (TBA) was observed after 181 days of operation, and stable removal was achieved throughout the remainder of the study. Simultaneously, both the MTBE only and the MTBE and EtOH iron‐reducing batch serum bottles also began to degrade MTBE. Bottles were respiked and the degradation rate was determined to be 2.36 ± 0.10 × 10−4 mmol MTBE/min‐kgVSS. The EtOH present with MTBE degraded faster (7.76 ± 0.08 × 10−3 mmol EtOH/min‐kg VSS) but did not have a noticeable effect on the rate of MTBE degradation. No evidence of TBA degradation was observed by the iron‐reducing cultures. Stoichiometry of iron utilization was determined from the iron balance of the continuous‐flow reactor, and it was found that the bulk of the electron acceptor was required for energy and maintenance with little remaining for cell synthesis. This is consistent with a yield coefficient of less than 0.1. Molecular analysis of the iron‐reducing culture by denaturing gradient gel electrophoresis indicated that uncultured strains of δ‐Proteobacteria were dominant in the reactor.
Kinetics of Removal of Particulate Chemical Oxygen Demand in the Activated‐Sludge Process
Authors: Jimenez Jose A. , La Motta Enrique J. , Parker Denny S.
Published: October 2005

The existing theories incorporated to state‐of‐the‐art, activated‐sludge‐consensus models indicate that the removal of particulate substrate from the liquid in the activated‐sludge process is a two‐step process: instantaneous enmeshment of particles and hydrolysis followed by oxidation. However, experimental observations indicate that the removal of particles is not instantaneous and needs a more accurate description. This removal process can actually be described as a three‐step process: flocculation, hydrolysis, and oxidation. The principal objective of this research was to observe and model the kinetics of the removal of suspended particles and colloidal particles. A first‐order, particulate‐removal expression, based on flocculation, accurately described the removal rates for supernatant suspended solids and colloidal chemical oxygen demand (COD). The rate of reaction for removal of colloidal COD was slow and comparable to that for soluble organic matter.
Effects of Reduced Return Activated Sludge Flows and Volume on Anaerobic Zone Performance for a Septic Wastewater Biological Phosphorus Removal System
Authors: Magro Daniel , Elias Steven L. , Randall Andrew Amis
Published: October 2005

Enhanced biological phosphorous removal (EBPR) performance was found to be adequate with reduced return‐activated sludge (RAS) flows (50% of available RAS) to the anaerobic tank and smaller‐than‐typical anaerobic zone volume (1.08 hours hydraulic retention time [HRT]). Three identical parallel biological nutrient removal pilot plants were fed with strong, highly fermented (160 mg/L volatile fatty acids [VFAs]), domestic and industrial wastewater from a full‐scale wastewater treatment facility. The pilot plants were operated at 100, 50, 40, and 25% RAS (percent of available RAS) flows to the anaerobic tank, with the remaining RAS to the anoxic tank. In addition, varying anaerobic HRT (1.08 and 1.5 hours) and increased hydraulic loading (35% increase) were examined. The study was divided into four phases, and the effect of these process variations on EBPR were studied by having one different variable between two identical systems. The most significant conclusion was that returning part of the RAS to the anaerobic zone did not decrease EBPR performance; instead, it changed the location of phosphorous release and uptake. Bringing less RAS to the anaerobic and more to the anoxic tank decreased anaerobic phosphorus release and increased anoxic phosphorus release (or decreased anoxic phosphorus uptake). Equally important is that, with VFA‐rich influent wastewater, excessive anaerobic volume was shown to hurt overall phosphorus removal, even when it resulted in increased anaerobic phosphorus release.
Comparative Assessment of Municipal Wastewater Disposal Methods in Southeast Florida
Authors: Bloetscher Frederick , Englehardt James D. , Chin David A. , Rose Joan B. , Tchobanoglous George , Amy Vincent P. , Gokgoz Sinem
Published: October 2005

A comparative assessment of the risks of three effluent disposal alternatives currently available to wastewater utilities in Southeast Florida is presented in this paper. The alternatives are: deep well injection and ocean outfalls following secondary treatment, and surface water (canal) discharges following secondary wastewater treatment, filtration and nutrient removal. Water quality data, relative to disposal of wastewater treatment plant effluent were gathered, along with water quality data on the receiving waters, from utilities. Comparisons and conclusions regarding potential health concerns associated with the three disposal alternatives are presented. The results indicated that health risks associated with deep wells were generally lower than those of the other two alternatives. The proximity of injection wells to aquifer storage and recovery wells was a determining factor relative to injection well risk. Urban ecological risks were also indicated to be lower, though impacts of urban water use/reuse to the Everglades were not studied. Additional data collection and analysis were recommended to understand the effects of wastewater management on the cycling of water, nutrients and other constituents on southeast Florida. In particular, it was recommended that monitoring of effluents for nitrosamines and pharmaceutically active substances be implemented on a broad scale.
Temperature Modeling in Activated Sludge Systems: A Case Study
Authors: Makinia Jacek , Wells Scott A. , Zima Piotr
Published: October 2005

A model of temperature dynamics was developed as part of a general model of activated‐sludge reactors. Transport of heat was described by the one‐dimensional, advection‐dispersion equation, with a source term based on a theoretical heat balance over the reactor. The model was compared to several reference models, including a tanks‐in‐series model and the dispersion model with heat components neglecting biochemical‐energy inputs and other activated‐sludge, heat‐balance terms. All the models were tested under steady‐state and dynamic conditions at a full‐scale facility, the Rock Creek wastewater treatment plant in Hillsboro, Oregon, using meteorological data from a station located 16 km from the plant. The dispersion model and tanks‐in‐series model matched in situ temperature data with absolute‐mean errors less than 0.1°C. Neglecting biochemical‐heat‐energy inputs in the activated‐sludge reactor underestimated temperatures by up to 0.5°C. The biochemical‐heat‐energy inputs accounted for 30 to 40% of the total heat flux throughout the year.
Accelerometer-Measured Physical Activity, Sedentary Time, and Heart Failure Risk in Women Aged 63 to 99 Years
Authors: LaMonte Michael J. , LaCroix Andrea Z. , Nguyen Steve , Evenson Kelly R. , Di Chongzhi , Stefanick Marcia L. , Hyde Eric T. , Anuskiewicz Blake , Eaton Charles B.
Published: February 2024

Importance

Heart failure (HF) prevention is paramount to public health in the 21st century.

Objective

To examine incident HF and its subtypes with preserved ejection fraction (HFpEF) and reduced EF (HFrEF) according to accelerometer-measured physical activity (PA) and sedentary time.

Design, Setting, and Participants

This was a prospective cohort study, the Objective Physical Activity and Cardiovascular Health (OPACH) in Older Women study, conducted from March 2012 to April 2014. Included in the analysis were women aged 63 to 99 years without known HF, who completed hip-worn triaxial accelerometry for 7 consecutive days. Follow-up for incident HF occurred through February 2022. Data were analyzed from March to December 2023.

Exposure

Daily PA (total, light, moderate to vigorous PA [MVPA], steps) and sedentary (total, mean bout duration) behavior.

Main Outcomes and Measures

Adjudicated incident HF, HFpEF, and HFrEF.

Results

A total of 5951 women (mean [SD] age, 78.6 [6.8] years) without known HF were included in this analysis. Women self-identified with the following race and ethnicity categories: 2004 non-Hispanic Black (33.7%), 1022 Hispanic (17.2%), and 2925 non-Hispanic White (49.2%). There were 407 HF cases (257 HFpEF; 110 HFrEF) identified through a mean (SD) of 7.5 (2.6) years (range, 0.01-9.9 years) of follow-up. Fully adjusted hazard ratios (HRs) for overall HF, HFpEF, and HFrEF associated with a 1-SD increment were 0.85 (95% CI, 0.75-0.95), 0.78 (95% CI, 0.67-0.91), and 1.02 (95% CI, 0.81-1.28) for minutes per day total PA; 0.74 (95% CI, 0.63-0.88), 0.71 (95% CI, 0.57-0.88), and 0.83 (95% CI, 0.62-1.12) for steps per day; and 1.17 (95% CI, 1.04-1.33), 1.29 (95% CI, 1.10-1.51), and 0.94 (95% CI, 0.75-1.18) for minutes per day total sedentary. Cubic spline curves for overall HF and HFpEF were significant inverse for total PA and steps per day and positive for total sedentary. Light PA and MVPA were inversely associated with overall HF (HR per 1 SD: 0.88; 95% CI, 0.78-0.98 and 0.84; 95% CI, 0.73-0.97) and HFpEF (0.80; 95% CI, 0.70-0.93 and 0.85; 95% CI, 0.72-1.01) but not HFrEF. Associations did not meaningfully differ when stratified by age, race and ethnicity, body mass index, physical function, or comorbidity score. Results for sedentary bout duration were inconsistent.

Conclusions and Relevance

Higher accelerometer-measured PA (MVPA, light PA, steps per day) was associated with lower risk (and greater total sedentary time with higher risk) of overall HF and HFpEF in a racially and ethnically diverse cohort of older women. Increasing PA and reducing sedentary time for primary HFpEF prevention may have relevant implications for cardiovascular resilience and healthy aging in later life.
Annular Erythematous Eruption in a Pediatric Patient
Authors: Sheriff Samar , Bahrami Soon , Schadt Courtney R.
Published: February 2024

An 11-year-old girl presented in autumn with an asymptomatic rash on her arms, face, and legs of a 3-week duration. What is your diagnosis?
Site of Ambulance Origination and Billing for Out-of-Network Services
Authors: Gong Jung Ho , Azad Chao Long , Zhang Gongliang , Means Kenneth R. , Aliu Oluseyi , Giladi Aviram M.
Published: February 2024

Importance

The No Surprises Act implemented in 2022 aims to protect patients from surprise out-of-network (OON) bills, but it does not include ground ambulance services. Understanding ground ambulance OON and balance billing patterns from previous years could guide legislation aimed to protect patients following ground ambulance use.

Objective

To characterize OON billing from ground ambulance services by evaluating whether OON billing risk differs by the site of ambulance origination (home, hospital, nonhospital medical facility, or scene of incident).

Design, Setting, and Participants

Cross-sectional study of the Merative MarketScan dataset between January 1, 2015, and December 31, 2020, using claims-based data from employer-based private health insurance plans in the US. Participants included patients who utilized ground ambulances during the study period. Data were analyzed from June to December 2023.

Exposure

Medical encounter requiring ground ambulance transportation.

Main Outcomes and Measures

Ground ambulance OON billing prevalence was calcuated. Linear probability models adjusted for state-level mixed effects were fit to evaluate OON billing probability across ambulance origins. Secondary outcomes included the allowed payment, patient cost-sharing amounts, and potential balance bills for OON ambulances.

Results

Among 2 031 937 ground ambulance services (1 375 977 unique patients) meeting the inclusion and exclusion criteria, 1 072 791 (52.8%) rides transported men, and the mean (SD) patient age was 41 (18) years. Of all services, 1 113 676 (54.8%) were billed OON. OON billing probabilities for ambulances originating from home or scene were higher by 12.0 percentage points (PP) (95% CI, 11.8-12.2 PP; P < .001 for home; 95% CI, 11.7-12.2 PP; P < .001 for scene) vs those originating from hospitals. Mean (SD) total financial burden, including cost-sharing and potential balance bills per ambulance service, was $434.70 ($415.99) per service billed OON vs $132.21 ($244.92) per service billed in-network.

Conclusions and Relevance

In this cross-sectional study of over 2 million ground ambulance services, ambulances originating from home, the scene of an incident, and nonhospital medical facilities were more likely to result in OON bills. Legislation is needed to protect patients from surprise billing following use of ground ambulances, more than half of which resulted in OON billing. Future legislation should at minimum offer protections for these subsets of patients often calling for an ambulance in urgent or emergent situations.
Near‐Unity Quantum Yield ZnSeTe Quantum Dots Enabled by Controlling Shell Growth for Efficient Deep‐Blue Light‐Emitting Diodes
Authors: Cheng Chunyan , Yu Binbin , Huang Fei , Gao Lei , Cao Kequan , Zang Panpan , Zheng Kaibo , Tian Jianjun
Published: February 2024

Core–shell structural ZnSeTe/ZnSe/ZnS quantum dots (QDs) have attracted great attention for advanced illumination and displays because of their environmentally friendly composition, but still suffering from poor photoluminescence (PL) and electroluminescence (EL) performance due to severe non‐radiative charge recombination. Herein, a stepwise injection shell growth process to manipulate the monomer concentration and ensure adequate growth interval is devised, which enables the controllable uniform epitaxial growth of ZnSe and ZnS shells on the ZnSeTe core, thus relieving the lattice distortion and defects to greatly suppress the non‐radiative charge recombination. The ZnSeTe/ZnSe/ZnS QDs presented deep‐blue emission at 448 nm with narrow full width at half maximum (FWHM, 23 nm), and near‐unity PL quantum yield (PLQY, ≈100%) The light‐emitting diodes (LEDs) based on the QDs exhibited a high external quantum efficiency (EQE) of 10.9%, a maximum brightness of 10240 cd cm−2, and a high current efficiency of 7.9 cd A−1, demonstrating a good performance for deep blue QDs LEDs (QLEDs) This shell growth strategy will be an effective approach to achieving efficient QDs and QLEDs.
Heteroatom Engineering of a Dibenzo[g,p]Chrysene‐Based Hole Transporting Material Provides High‐Performance Perovskite Solar Cells
Authors: Zhang Xianfu , Zhang Shaochen , Liao Xiaobin , Ding Bin , Rahim Ghadari , Zhao Kangning , Chen Jianlin , Han Mingyuan , Zhou Ying , Shi Pengju , Zhang Kai , Kinge Sachin , Zhang Hong , Wang Rui , Brooks Keith G. , Dai Songyuan , Liu Xuepeng , Fei Zhaofu , Dyson Paul J. , Nazeeruddin Mohammad Khaja , Ding Yong
Published: February 2024

Hole‐transporting materials (HTMs) are indispensable for realizing efficient and stable perovskite solar cells (PSCs). Herein, a novel dibenzo[g,p]chrysene‐based HTM, termed FTPE‐OSMe, is synthesized with peripheral methoxy‐ and methylthio‐groups, which contrasts with most other small molecule HTMs that feature only methoxy‐groups. The presence of methoxy‐ and methylthio‐groups endows FTPE‐OSMe with appropriate energy levels, high‐hole mobility and enhanced interfacial interactions. PSCs employing Li‐TFSI and 4‐tert‐butylpyridine‐doped FTPE‐OSMe demonstrate a remarkable power conversion efficiency (PCE) of 24.94% (certified 24.89%). The larger‐scale PSC (1.0 cm2) and module (29.0 cm2) yield PCEs of 23.57 and 20.22%, respectively. In addition, the dopant‐free FTPE‐OSMe‐based PSCs exhibit a respectable PCE of 22.40% and excellent stability.
Rational Design of Dendritic Phase‐Pure Tin Antimonide Intermetallic Film‐Based Negatrodes for Commercially‐Viable Flexible Sodium‐Ion Pouch Cell Battery
Authors: Jena Sambedan , Sathishkumar Lakshmanan , Tran Duy Thanh , Jeong Kwang‐Un , Kim Nam Hoon , Lee Joong Hee
Published: February 2024

Exploiting the ability to directly deposit larger‐sized, flexible, alloying‐type sodium‐ion battery electrodes without the need of additional inactive components and processing steps is a strategic way to achieve higher gravimetric capacities which will be suitable for commercial‐level sodium‐ion (SIB) pouch cell manufacturing. In this regard, a simple, template‐free electroplating protocol is reported for designing phase‐pure tin antimonide (TA)‐based negatrode. An optimum control over the potentiostatic electroplating parameters allows the preferential formation of dendritic nanostructures over an electroplated foam‐based current collector. The prepared negatrode and Mn‐based Prussian blue analog positrode in full coin cell format deliver an average nominal working voltage of 3.0 V with a discharge energy density of 342 Wh kg−1. In single‐layer full pouch cell format, an 8.01 mAh capacity (89.89 mAh g−1, 593.3 µAh cm−2) is achieved at an undeformed state and 97.12% capacity is retained at 180° bend condition. In multi‐layer full pouch cell format, a 35.86 mAh capacity (80.58 mAh g−1, 531.2 µAh cm−2) is achieved with 62.77% capacity retention after 200 cycles (0.125 C). The results of this work showcase how a simple, template free, aqueous electrolyte based electroplating protocol can be developed for the direct fabrication of large‐sized, flexible, alloying‐type negatrodes for commercial SIB pouch cells.
Planar Chiral Thermally Activated Delayed Fluorescence Materials Based on Di[2.2]paracyclophane for Circularly Polarized Electroluminescence
Authors: Gong Minghua , Yuan Li , Zheng You‐Xuan , Zheng Wen‐Hua
Published: February 2024

In this study, featuring di[2.2]paracyclophane (DpCp) amine derivatives as electron donors and 4‐(4,6‐diphenyl‐1,3,5‐triazin‐2‐yl)phenyl (Trz) as the electron acceptor, four thermally activated delayed fluorescence (TADF) molecules are disclosed. The C2 symmetric molecules, DpCpN‐Trz and DpCpCz‐Trz, bearing a chair‐like planar chiral di[2.2]paracyclophane moiety, are obtained as optically pure enantiomers (R/S)‐C‐DpCpN‐Trz and (R/S)‐C‐DpCpCz‐Trz. And the compounds B‐DpCpN‐Trz and B‐DpCpCz‐Trz with a bridge‐like di[2.2]paracyclophane skeleton are meso‐compounds, thus without optically activity. All emitters show blue emissions peaking from 464 to 485 nm, accompanied by high photoluminescence quantum efficiency (up to 93%). The enantiomers (R/S)‐C‐DpCpN‐Trz and (R/S)‐C‐DpCpCz‐Trz exhibit symmetric circularly polarized photoluminescence spectra with dissymmetry factors (|gPL|) ranging from 3.8 × 10−4 to 6.7 × 10−4 in toluene and films. The organic light‐emitting diodes (OLEDs) fabricated with these emitters achieve maximum external quantum efficiencies of up to 19.5%. Notably, the circularly polarized OLEDs (CP‐OLEDs) with (R/S)‐C‐DpCpN‐Trz and (R/S)‐C‐DpCpCz‐Trz demonstrate |gEL| factors of up to 7.6 × 10−4. This study demonstrates a feasible way to design TADF materials and enantiomers by incorporating DpCp derivatives for CP‐OLEDs.
A Supercapacitor Architecture for Extreme Low‐Temperature Operation Featuring MXene/Carbon Nanotube Electrodes with Vertically Aligned Channels and a Novel Freeze‐Resistant Electrolyte
Authors: Zhao Tianyu , Yang Dongzhi , Li Bai‐Xue , Shi Yongzheng , Quan Qiuyan , Koratkar Nikhil , Yu Zhong‐Zhen
Published: February 2024

The electrochemical performance of supercapacitors drops precipitously at extreme low temperatures due to a multitude of reasons, which includes electrolyte freezing, sluggish ion transport in the electrode and electrolyte, and high charge transfer resistance at electrode–electrolyte interfaces. To address high interface resistance, a new supercapacitor architecture is reported, in which MXene/carbon nanotube electrodes with vertically aligned channels are synthesized to reduce tortuosity and maximize the electrode–electrolyte contact area. These electrodes are fabricated using a directional‐freezing strategy, generating direct and fast ion transport pathways. Further, a freeze‐resistant electrolyte which shows high ionic conductivity is synthesized by designing a double‐crosslinked polymer network in a binary solvent consisting of ionic liquid and water, which exhibits an ultralow freezing temperature of −54 °C. An all‐in‐one supercapacitor is assembled by an integrated polymerization strategy to minimize interfacial resistances. The resulting device delivers a specific capacitance of 231 F g−1 at 2 mV s−1 and a maximum energy density of 10.17 Wh kg−1, while maintaining a capacitance retention of 92%, even at an extreme low temperature of −50 °C. The supercapacitor architecture developed in this study, demonstrates the feasibility of electrochemical energy storage at extreme low temperatures.
Ultrathin Composite Separator Based on Lithiated COF Nanosheet for High Stability Lithium Metal Batteries
Authors: Yu Guofang , Cui Yin , Lin Shenghao , Liu Ruliang , Liu Shaohong , Zhu Youlong , Wu Dingcai
Published: February 2024

Lithium metal is considered as the ultimate anode material for high‐energy‐density rechargeable batteries. However, lithium metal batteries (LMBs) with commercial separators still face some challenges such as low cycling efficiency and uncontrollable Li dendrite growth, which seriously hampers the commercialization of LMBs. In this study, a novel kind of ultrathin (6.2 µm) multifunctional composite separator (TpPa‐SO3Li@PE) is designed and prepared via coating lithiated covalent organic framework nanosheet (TpPa‐SO3Li) on the surface of commercial polyethylene separator (PE). TpPa‐SO3Li@PE integrates features of the nanochannel arrays and abundant immobilized anionic sites, leading to efficient Li+ conduction and homogeneous Li+ flow. As a result, TpPa‐SO3Li@PE exhibits excellent Li+ conductivity (0.96 mS cm−1) and Li+ transference number (0.83) at room temperature, and Li/Li symmetric cell using TpPa‐SO3Li@PE separator possesses highly stable Li plating/striping (over 2600 h) at high current density (5 mA cm−2). Moreover, Li/LiFePO4 full cells with TpPa‐SO3Li@PE separator show excellent cycling performance (high capacity retention of 94.9% after 300 cycles at 1 C) and superior rate performance (high specific capacity of 113.6 mAh g−1 at 5 C).
Roadmap for Clinical Translation of Mobile Microrobotics
Authors: Bozuyuk Ugur , Wrede Paul , Yildiz Erdost , Sitti Metin
Published: February 2024

Medical microrobotics is an emerging field to revolutionize clinical applications in diagnostics and therapeutics of various diseases. On the other hand, the mobile microrobotics field has important obstacles to pass before clinical translation. This article focuses on these challenges and provides a roadmap of medical microrobots to enable their clinical use. From the concept of a “magic bullet” to the physicochemical interactions of microrobots in complex biological environments in medical applications, there are several translational steps to consider. Clinical translation of mobile microrobots is only possible with a close collaboration between clinical experts and microrobotics researchers to address the technical challenges in microfabrication, safety, and imaging. The clinical application potential can be materialized by designing microrobots that can solve the current main challenges, such as actuation limitations, material stability, and imaging constraints. The strengths and weaknesses of the current progress in the microrobotics field are discussed and a roadmap for their clinical applications in the near future is outlined.
Defect Passivation Refinement in Perovskite Photovoltaics: Achieving Efficiency over 45% under Low‐Light and Low‐Temperature Dual Extreme Conditions
Authors: Wang Yajie , Yang Tinghuan , Cai Weilun , Mao Peng , Yang Yang , Wu Nan , Liu Chou , Wang Shiqiang , Du Yachao , Huang Wenliang , Zhao Guangtao , Ding Zicheng , Yuan Ningyi , Ding Jianning , Zhong Yufei , Liu Shengzhong (Frank) , Zhao Kui
Published: February 2024

Perovskite photovoltaics have emerged as the most promising candidates for next‐generation light‐to‐electricity technology. However, their practical application still suffers from energy loss induced by intrinsic defects within the perovskite lattice. Here, a refined defect passivation in perovskite films is designed, which shows a multi‐interaction mechanism between the perovskite and passivator. Interestingly, a shift of molecular bonding is observed upon cooling down the film, leading to a stronger passivation of iodine/formamidine vacancies. Such mechanism on device under low‐light and low‐temperature conditions is further leveraged and a record efficiency over 45% with durable ambient stability (T90 > 4000 h) is obtained. The pioneer application of perovskite solar cells in above dual extreme conditions in this work reveals the key principles of designing functional groups for the passivators, and also demonstrates the capability of perovskites for diverse terrestrial energy conversion applications in demanding environments such as polar regions and outer space.
Near‐Infrared Light Emitting Metal Halides: Materials, Mechanisms, and Applications
Authors: Liu Ying , Di Stasio Francesco , Bi Chenghao , Zhang Jibin , Xia Zhiguo , Shi Zhifeng , Manna Liberato
Published: February 2024

Near‐Infrared (NIR) light emitting metal halides are emerging as a new generation of optical materials owing to their appealing features, which include low‐cost synthesis, solution processability, and adjustable optical properties. NIR‐emitting perovskite‐based light‐emitting diodes (LEDs) have reached an external quantum efficiency (EQE) of over 20% and a device stability of over 10,000 h. Such results have sparked an interest in exploring new NIR metal halide emitters. In this review, several different types of NIR‐emitting metal halides, including lead/tin bromide/iodide perovskites, lanthanide ions doped/based metal halides, double perovskites, low dimensional hybrid and Bi3+/Sb3+/Cr3+ doped metal halides, are summarized, and their recent advancement is assessed. The characteristics and mechanisms of narrow‐band or broadband NIR luminescence in all these materials are discussed in detail. Also, the various applications of NIR‐emitting metal halides are highlighted and an outlook for the field is provided.
Recent Advances in Flexible Pressure Sensors Based on MXene Materials
Authors: Qin Ruzhan , Nong Juan , Wang Keqiang , Liu Yishen , Zhou Songbin , Hu Mingjun , Zhao Hongbin , Shan Guangcun
Published: February 2024

In the past decade, with the rapid development of wearable electronics, medical health monitoring, the Internet of Things, and flexible intelligent robots, flexible pressure sensors have received unprecedented attention. As a very important kind of electronic component for information transmission and collection, flexible pressure sensors have gained a wide application prospect in the fields of aerospace, biomedical and health monitoring, electronic skin, and human–machine interface. In recent years, MXene has attracted extensive attention because of its unique 2D layered structure, high conductivity, rich surface terminal groups, and hydrophilicity, which has brought a new breakthrough for flexible sensing. Thus, it has become a revolutionary pressure‐sensitive material with great potential. In this work, the recent advances of MXene‐based flexible pressure sensors are reviewed from the aspects of sensing type, sensing mechanism, material selection, structural design, preparation strategy, and sensing application. The methods and strategies to improve the performance of MXene‐based flexible pressure sensors are analyzed in details. Finally, the opportunities and challenges faced by MXene‐based flexible pressure sensors are discussed. This review will bring the research and development of MXene‐based flexible sensors to a new high level, promoting the wider research exploitation and practical application of MXene materials in flexible pressure sensors.
Contactless Scanning Near‐Field Optical Dilatometry Imaging at the Nanoscale
Authors: Wong Victor , Ezugwu Sabastine , Fanchini Giovanni
Published: February 2024

To date, there are very few experimental techniques, if any, that are suitable for the purpose of acquiring quantitative maps of the thermal expansivity of 2D materials and nanostructured thin films with nanoscale lateral resolution in spite of huge demand for nanoscale thermal management, for example in designing integrated circuitry for power electronics. Besides, contactless analytical tools for determining the thermal expansion coefficient (TEC) are highly desirable because probes in contact with the sample significantly perturb any thermal measurements. Here, ω‐2ω near‐field thermoreflectance imaging is presented as a novel, all‐optical, and contactless technique to map the TEC at the nanoscale with precision. Testing of this technique is performed on nanogranular films of gold and multilayer graphene (ML‐G) platelets. With ω‐2ω near‐field thermoreflectance, it is demonstrated that the TEC of Au is higher at the metal‐insulator interface, with an average of (17.12 ± 2.30) ×10−6 K−1 in agreement with macroscopic techniques. For ML‐G, the average TEC is (−5.77 ± 3.79) x10−6 K−1 and is assigned to in‐plane vibrational bending modes. A vibrational‐thermal transition from graphene to graphite is observed, where the TEC becomes positive as the ML thickness increases. The nanoscale method here reported demonstrates results in excellent agreement with its macroscopic counterparts, as well as superior capabilities to probe 2D materials and interfaces.
Shared‐Aperture 2‐Bit Coding Metasurface for Simultaneous Manipulation of Space Wave and Surface Wave
Authors: Yin Jia‐Yuan , Wu Zhuojian , Deng Jing‐Ya
Published: February 2024

A shared‐aperture 2‐bit coding metasurface for simultaneously and independently manipulating space wave and surface wave is proposed in this paper. When the proposed coding metasurface is expected to modulate space wave, the unit cells can control the reflection phase. The reflected wave becomes various according to the specific coding sequence. When the proposed coding metasurface acts as spoof surface plasmon polaritons (SSPP) transmission line, the unit cells can modulate the surface impedance. With periodic modulation to the surface impedance, electromagnetic wave can be radiated into free space and the radiation beam scans as frequency changes. Space wave modulator works at 22.5 GHz, while the surface wave modulator works during the frequency range of 6.5–11.4 GHz. The total scanning angle of the radiated beam of surface wave modulator covers from −54° to 52°, with an average gain of 10.64 dBi. Simultaneous manipulation of both space wave and surface wave by a single metasurface makes the proposed device promising in the new radar and satellite communication systems with compact requirement.
Blue‐Light‐Excitable Red‐to‐Near Infrared Photoluminescence in 0D Antimony(III) Bromide Hybrids for Supplemental Lighting
Authors: Jin Jiance , Geng Shining , Han Kai , Xiao Zewen , Xia Zhiguo
Published: February 2024

Antimony (III)‐containing halide hybrids possess a distinctive stereoactivity with a 5s2 lone pair, which further induces significant structural distortions upon light excitation. Herein disordered dis‐[TPPen]2SbBr5 (TPPen = triphenylpentylphosphonium) and ordered ord‐[TPPen]2SbBr5, have been synthesized and exhibit self‐trapped excitons (STEs) emissions in the red‐to‐near infrared (NIR) range. Benefiting from a high distortion degree of STEs confined within the [SbBr5]2− unit and the pronounced alterations in the Sb─Br bond lengths upon blue‐light excitation, dis‐[TPPen]2SbBr5 achieves a greater level of excited state distortion and a larger Stokes shift than those of ord‐[TPPen]2SbBr5. The fabrication of blue light excited NIR light‐emitting device based on dis‐[TPPen]2SbBr5 demonstrates the prospective application in night vision supplemental lighting and non‐destructive examination. This work provides valuable molecular design strategies for the NIR luminescent materials in hybrid metal halides.