4-factor prothrombin complex concentrate is not inferior to andexanet alfa for the reversal or oral factor Xa inhibitors: An Eastern Association for the Surgery of Trauma multicenter study.

BACKGROUND: Andexanet Alfa (AA) is the only FDA approved reversal agent for apixaban and rivaroxaban (DOAC). There are no studies comparing its efficacy with 4-Factor Prothrombin Complex Concentrate (PCC). This study aimed to compare PCC to AA for DOAC reversal, hypothesizing non-inferiority of PCC. METHODS: We performed a retrospective, non-inferiority multicenter study of adult patients admitted from July 1, 2018 to December 31, 2019 who had taken a DOAC within 12 hours of injury, were transfused red blood cells (RBCs) or had traumatic brain injury, and received AA or PCC. Primary outcome was PRBC unit transfusion. Secondary outcome with ICU length of stay. MICE imputation was used to account for missing data and zero-inflated poisson regression was used to account for an excess of zero units of RBC transfused. 2 Units difference in RBC transfusion was selected as non-inferior. RESULTS: Results: From 263 patients at 10 centers, 77 (29%) received PCC and 186 (71%) AA. Patients had similar transfusion rates across reversal treatment groups (23.7% AA vs 19.5% PCC) with median transfusion in both groups of 0 RBC. According to the Poisson component, PCC increases the amount of RBC transfusion by 1.02 times (95% CI: 0.79-1.33) compared to AA after adjusting for other covariates. The averaged amount of RBC transfusion (non-zero group) is 6.13. Multiplying this number by the estimated rate ratio, PCC is estimated to have an increase RBC transfusion by 0.123 (95% CI: 0.53-2.02) units compared to AA. CONCLUSION: PCC appears non-inferior to AA for reversal of DOACs for RBC transfusion in traumatically injured patients. Additional prospective, randomized trials are necessary to compare PCC and AA for the treatment of hemorrhage in injured patients on DOACs. LEVEL OF EVIDENCE: Therapeutic/Care Management, Level III.

Patient sex and outcomes in children with life-threatening hemorrhage.

BACKGROUND: Recent data suggest female sex imparts a survival benefit after trauma in adults. The independent associations between patient sex and age with outcomes have not been examined in children with life-threatening hemorrhage (LTH) from all etiologies. STUDY DESIGN AND METHODS: In a secondary analysis of a multicenter prospective observational study of children with LTH, Massive Transfusion in Children (MATIC), we analyzed if patient sex and age were associated with differences in severity of illness, therapies, and outcomes. Primary outcomes were 24 hour mortality and weight-adjusted transfusion volume during LTH. Kruskal-Wallis, chi-square testing, and multivariable linear regression were used for adjusted analyses. RESULTS: Of 449 children, 45% were females and 55% were males. Females were more commonly younger, white, and with less trauma as the etiology of LTH compared to males. Markers of clinical severity were similar between groups, except injury severity score (ISS) was higher in females in the trauma subgroup. In terms of resuscitative practices, females received greater weight-adjusted total transfusion volumes compared to males (76 (40-150) mL/kg vs. 53 (24-100) mL/kg), as well as increased red blood cells (RBCs), plasma, and platelets compared to males. After adjustment for confounders, female sex and age 0-11 years were independently associated with increased transfusion volume during LTH. There were no differences in mortality or adverse outcomes according to patient sex. CONCLUSION: Patient sex and age may impact factors associated with LTH and therapies received. Studies in developmental hemostasis are needed to determine the optimal transfusion strategy for LTH according to patient sex and age.

Increased platelet to red blood cell transfusion ratio associated with acute kidney injury in children with life-threatening bleeding.

INTRODUCTION: Transfusion may increase the risk of organ failure through immunomodulatory effects. The primary objective of this study was to assess for patient or transfusion-related factors that are independently associated with the risk of acute kidney injury (AKI) and acute respiratory distress syndrome (ARDS) in a cohort of children with life-threatening bleeding from all etiologies. METHODS: In a secondary analysis of the prospective observational massive transfusion in children (MATIC) study, multivariable logistic regression was performed in an adjusted analysis to determine if blood product ratios or deficits were independently associated with AKI or ARDS in children with life-threatening bleeding. RESULTS: There were 449 children included with a median (interquartile range, IQR) age of 7.3 years (1.7-14.7). Within 5 days of the life-threatening bleeding event, AKI occurred in 18.5% and ARDS occurred in 20.3% of the subjects. Every 10% increase in the platelet to red blood cell transfusion ratio is independently associated with a 12.7% increase in the odds of AKI (adjusted odds ratio 1.127; 95% confidence interval 1.025-1.239; p-value .013). Subjects with operative or medical etiologies were independently associated with an increased risk of AKI compared to those with traumatic injury. No transfusion-related variables were independently associated with the risk of developing ARDS. CONCLUSION: The use of increased platelet to red blood cell transfusion ratios in children with life-threatening bleeding of any etiology may increase the risk of AKI but not ARDS. Prospective trials are needed to determine if increased platelet use in this cohort increases the risk of AKI to examine possible mechanisms.

Evaluating potential disparities in geospatial access to American College of Surgeons/American Association for the Surgery of Trauma-verified emergency general surgery centers.

BACKGROUND: The American Association for the Surgery of Trauma and the American College of Surgeons have recently introduced emergency general surgery (EGS) center verification, which could enhance patient outcomes. Distance and resource availability may affect access to these centers, which has been linked to higher mortality. Although many patients can receive adequate care at community centers, those with critical conditions may require specialized treatment at EGS-verified centers. We aimed to evaluate geospatial access to potential EGS-verified centers and identify disparities across different scenarios of EGS verification program uptake in the United States. METHODS: We used hospital capabilities and verified pilot centers to estimate potential patterns of which centers would become EGS verified under four scenarios (EGS centers, high-volume EGS centers, high-volume EGS plus level 1 trauma centers, and quaternary referral centers). We calculated the spatial accessibility index using an enhanced two-step floating catchment technique to determine geospatial access for each scenario. We also evaluated social determinants of health across geospatial access using the Area Deprivation Index (ADI). RESULTS: A total of 1,932 hospitals were categorized as EGS centers, 307 as high-volume EGS centers, 401 as high-volume EGS plus level 1trauma centers, and 146 as quaternary centers. Spatial accessibility index decreased as the stringency of EGS verification increased in each scenario (226.6 [111.7-330.7], 51.8 [0-126.1], 71.52 [3.34-164.56], 6.2 [0-62.2]; p < 0.001). Within each scenario, spatial accessibility index also declined as the ADI quartile increased ( p < 0.001). The high-volume EGS plus level 1trauma center scenario had the most significant disparity in access between the first and fourth ADI quartiles (-54.68). CONCLUSION: Access to EGS-verified centers may vary considerably based on the program's implementation. Disadvantaged communities may be disproportionately affected by limited access. Further work to study regional needs can allow a strategic implementation of the EGS verification program to optimize outcomes while minimizing disparities. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level IV.

Impact of patient, system, and environmental factors on utilization of air medical transport after trauma.

BACKGROUND: Air medical transport (AMT) improves outcomes for severely injured patients. The decision to fly patients is complex and must consider multiple factors. Our objective was to evaluate the interaction between geography, patient and environmental factors, and emergency medical services (EMS) system resources on AMT after trauma. We hypothesize that significant geographic variation in AMT utilization will be associated with varying levels of patient, environmental, and EMS resources. METHODS: Patients transported by EMS in the Pennsylvania state trauma registry 2000 to 2017 were included. We used our previously developed Air Medical Prehospital Triage (AMPT; ≥2 points triage to AMT) score and Geographic Emergency Medical Services Index (GEMSI; higher indicates more system resources) as measures for patient factors and EMS resources, respectively. A mixed-effects logistic regression model determined the association of AMT utilization with patient, system, and environmental variables. RESULTS: There were 195,354 patients included. Fifty-five percent of variation in AMT utilization was attributed to geographic differences. Triage to AMT by the AMPT score was associated with nearly twice the odds of AMT utilization (adjusted odds ratio, 1.894; 95% confidence interval, 1.765-2.032; p < 0.001). Each 1-point increase in GEMSI was associated with a 6.1% reduction in odds of AMT (0.939; 0.922-0.957; p < 0.001). Younger age, rural location, and more severe injuries were also associated with increased odds of AMT ( p < 0.05). When categorized by GEMSI level, the AMPT score and patient factors were more important for predicting AMT utilization in the middle tercile (moderate EMS resources) compared with the lower (low EMS resources) and higher tercile (high EMS resources). Weather, season, time-of-day, and traffic were all associated with AMT utilization ( p < 0.05). CONCLUSION: Patient, system, and environmental factors are associated with AMT utilization, which varies geographically and by EMS/trauma system resource availability. A more comprehensive approach to AMT triage could reduce variation and allow more tailored efforts toward optimizing resource allocation and outcomes. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level III.

Association Between Emergency Medical Service Agency Volume and Mortality in Trauma Patients.

OBJECTIVE: The aim of this study was to evaluate the association of annual trauma patient volume on outcomes for emergency medical services (EMS) agencies. BACKGROUND: Regionalization of trauma care saves lives. The underlying concept driving this is a volume-outcome relationship. EMS are the entry point to the trauma system, yet it is unknown if a volume-outcome relationship exists for EMS. METHODS: A retrospective analysis of prospective cohort including 8 trauma centers and 20 EMS air medical and metropolitan ground transport agencies. Patients 18 to 90 years old with injury severity scores ≥9 transported from the scene were included. Patient and agency-level risk-adjusted regression determined the association between EMS agency trauma patient volume and early mortality. RESULTS: A total of 33,511 were included with a median EMS agency volume of 374 patients annually (interquartile range: 90-580). Each 50-patient increase in EMS agency volume was associated with 5% decreased odds of 6-hour mortality (adjusted odds ratio=0.95; 95% CI: 0.92-0.99, P =0.03) and 3% decreased odds of 24-hour mortality (adjusted odds ratio=0.97; 95% CI: 0.95-0.99, P =0.04). Prespecified subgroup analysis showed EMS agency volume was associated with reduced odds of mortality for patients with prehospital shock, requiring prehospital airway placement, undergoing air medical transport, and those with traumatic brain injury. Agency-level analysis demonstrated that high-volume (>374 patients/year) EMS agencies had a significantly lower risk-standardized 6-hour mortality rate than low-volume (<374 patients/year) EMS agencies (1.9% vs 4.8%, P <0.01). CONCLUSIONS: A higher volume of trauma patients transported at the EMS agency level is associated with improved early mortality. Further investigation of this volume-outcome relationship is necessary to leverage quality improvement, benchmarking, and educational initiatives.

Doing more with less: low-titer group O whole blood resulted in less total transfusions and an independent association with survival in adults with severe traumatic hemorrhage.

BACKGROUND: Low-titer group O whole blood (LTOWB) or component therapy (CT) may be used to resuscitate hemorrhaging trauma patients. LTOWB may have clinical and logistical benefits and may improve survival. OBJECTIVES: We hypothesized LTOWB would improve 24-hour survival in hemorrhaging patients and would be safe and equally efficacious in non-group O compared with group O patients. METHODS: Adult trauma patients with massive transfusion protocol activations were enrolled in this observational study. The primary outcome was 24-hour mortality. Secondary outcomes included 72-hour total blood product use. A Cox regression determined the independent associations with 24-hour mortality. RESULTS: In total, 348 patients were included (CT, n = 180; LTOWB, n = 168). Demographics were similar between cohorts. Unadjusted 24-hour mortality was reduced in LTOWB vs CT: 8% vs 19% (P = .003), but 6-hour and 28-day mortality were similar. In an adjusted analysis with multivariable Cox regression, LTOWB was independently associated with reduced 24-hour mortality (hazard ratio, 0.21; 95% CI, 0.07-0.67; P = .004). LTOWB patients received significantly less 72-hour total blood products (80.9 [41.6-139.3] mL/kg vs 48.9 [25.9-106.9] mL/kg; P < .001). In stratified 24-hour survival analyses, LTOWB was associated with improved survival for patients in shock or with coagulopathy. LTOWB use in non-group O patients was not associated with increased mortality, organ injury, or adverse events. CONCLUSION: In this hypothesis-generating study, LTOWB use was independently associated with improved 24-hour survival, predominantly in patients with shock or coagulopathy. LTOWB also resulted in a 40% reduction in blood product use which equates to a median 2.4 L reduction in transfused products.

Cation Exchange Reaction-Mediated Photothermal and Polarity-Switchable Photoelectrochemical Dual-Readout Biosensor.

Cation exchange (CE) is a burgeoning method for controlled crystal synthesis; however, its applications in bioanalysis are still in their infancy. Herein, we explored the transformation of ZnIn2S4 in properties after the CE reaction with Cu2+ ions; furthermore, the discrepancy was employed to design a dual-readout detection system of photothermal and polarity-switchable photoelectrochemical (PEC) immunoassays to realize reliable detection of carcinoembryonic antigen (CEA). In the presence of CEA, the CuO nanoparticles (CuO NPs) employed as dual-signal response probes would bond to the microplates and be acidolyzed by HCl to release Cu2+, which could replace Zn2+ and In3+ via the CE reaction. After the CE reaction is completed, the photocurrent would switch from a weak anodic photocurrent to a cathode one by using a 635 nm laser as a signal amplifier, while the photothermal signal would be enhanced with 808 nm laser illumination. On the basis of the polarity-switchable PEC strategy, CEA could be accurately detected from 0.1 to 50 ng mL-1 with a limit of detection (LOD) of 48 pg mL-1 (S/N = 3). Moreover, the photothermal assay for CEA detection possesses a linear range from 0.5 to 100 ng mL-1 with a LOD of 0.21 ng mL-1. In addition, the designed sensing platform only relies on devices with portability that are permitted for point-of-care detection.

Self-assembled p-n Ag2O@Bi2O2S nanoflower heterojunctions for sensitive photoelectrochemical immunoassay.

A new photoelectrochemical immunoassay based on self-assembled p-n Ag2O@Bi2O2S nanoflower heterojunction was designed and developed for quantitative monitoring of prostate-specific antigen (PSA) in biological fluids. Primarily, self-assembled p-n Ag2O@Bi2O2S nanoflower heterojunctions were served as the photoactive materials and coated onto the surface of electrodes. Subsequently, the glucose oxidase (GOx) was bound to the detection antibody (mAb2) labeled gold nanoparticles (Au NPs) and then were employed to accomplish a sandwich-like immunoreaction to generate H2O2 on a microplate incubated with monoclonal anti-PSA antibodies. In the presence of PSA, the product (H2O2) was catalyzed by the substrate, which was used as an electron sacrificial agent to improve signal conversion and capture of photogenerated electrons. Under optimum conditions, a wide linear range of 0.01-50 ng mL-1 and a low detection limit of 5.3 pg mL-1 were accomplished with the sensor, exhibiting an excellent photocurrent response. Moreover, the proposed sensor revealed satisfactory reproducibility, high selectivity, and acceptable accuracy for the real sample testing. Importantly, our work provides a novel strategy for high sensitivity detection of disease-associated biomarkers for the early diagnosis of cancers.

Atomically Site Synergistic Effects of Dual-Atom Nanozyme Enhances Peroxidase-like Properties.

Pursuing effective and generalized strategies for modulating the electronic structures of atomically dispersed nanozymes with remarkable catalytic performance is exceptionally attractive yet challenging. Herein, we developed a facile "formamide condensation and carbonization" strategy to fabricate a library of single-atom (M1-NC; 6 types) and dual-atom (M1/M2-NC; 13 types) metal-nitrogen-carbon nanozymes (M = Fe, Co, Ni, Mn, Ru, Cu) to reveal peroxidase- (POD-) like activities. The Fe1Co1-NC dual-atom nanozyme with Fe1-N4/Co1-N4 coordination displayed the highest POD-like activity. Density functional theory (DFT) calculations revealed that the Co atom site synergistically affects the d-band center position of the Fe atom site and served as the second reaction center, which contributes to better POD-like activity. Finally, Fe1Co1 NC was shown to be effective in inhibiting tumor growth both in vitro and in vivo, suggesting that diatomic synergy is an effective strategy for developing artificial nanozymes as novel nanocatalytic therapeutics.

The Geography of Injuries in Trauma Systems: Using Home as a Proxy for Incident Location.

INTRODUCTION: Effective trauma system organization is crucial to timely access to care and requires accurate understanding of injury and resource locations. Many systems rely on home zip codes to evaluate geographic distribution of injury; however, few studies have evaluated the reliability of home as a proxy for incident location after injury. METHODS: We analyzed data from a multicenter prospective cohort collected from 2017 to 2021. Injured patients with both home and incident zip codes were included. Outcomes included discordance and differential distance between home and incident zip code. Associations of discordance with patient characteristics were determined by logistic regression. We also assessed trauma center catchment areas based on home versus incident zip codes and variation regionally at each center. RESULTS: Fifty thousand one hundred seventy-five patients were included in the analysis. Home and incident zip codes were discordant in 21,635 patients (43.1%). Injuries related to motor vehicles (aOR: 4.76 [95% CI 4.50-5.04]) and younger adults 16-64 (aOR: 2.46 [95% CI 2.28-2.65]) were most likely to be discordant. Additionally, as injury severity score increased, discordance increased. Trauma center catchment area differed up to two-thirds of zip codes when using home versus incident location. Discordance rate, discordant distance, and catchment area overlap between home and incident zip codes all varied significantly by geographic region. CONCLUSIONS: Home location as proxy for injury location should be used with caution and may impact trauma system planning and policy, especially in certain populations. More accurate geolocation data are warranted to further optimize trauma system design.

Therapeutic Plasma Exchange Is Associated With Improved Major Adverse Kidney Events in Children and Young Adults With Thrombocytopenia at the Time of Continuous Kidney Replacement Therapy Initiation.

Therapeutic plasma exchange (TPE) has been shown to improve organ dysfunction and survival in patients with thrombotic microangiopathy and thrombocytopenia associated with multiple organ failure. There are no known therapies for the prevention of major adverse kidney events after continuous kidney replacement therapy (CKRT). The primary objective of this study was to evaluate the effect of TPE on the rate of adverse kidney events in children and young adults with thrombocytopenia at the time of CKRT initiation. DESIGN: Retrospective cohort. SETTING: Two large quaternary care pediatric hospitals. PATIENTS: All patients less than or equal to 26 years old who received CKRT between 2014 and 2020. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We defined thrombocytopenia as a platelet count less than or equal to 100,000 (cell/mm3) at the time of CKRT initiation. We ascertained major adverse kidney events at 90 days (MAKE90) after CKRT initiation as the composite of death, need for kidney replacement therapy, or a greater than or equal to 25% decline in estimated glomerular filtration rate from baseline. We performed multivariable logistic regression and propensity score weighting to analyze the relationship between the use of TPE and MAKE90. After excluding patients with a diagnosis of thrombotic thrombocytopenia purpura and atypical hemolytic uremic syndrome (n = 6) and with thrombocytopenia due to a chronic illness (n = 2), 284 of 413 total patients (68.8%) had thrombocytopenia at CKRT initiation (51% female). Of the patients with thrombocytopenia, the median (interquartile range) age was 69 months (13-128 mo). MAKE90 occurred in 69.0% and 41.5% received TPE. The use of TPE was independently associated with reduced MAKE90 by multivariable analysis (odds ratio [OR], 0.35; 95% CI, 0.20-0.60) and by propensity score weighting (adjusted OR, 0.31; 95% CI, 0.16-0.59). CONCLUSIONS: Thrombocytopenia is common in children and young adults at CKRT initiation and is associated with increased MAKE90. In this subset of patients, our data show benefit of TPE in reducing the rate of MAKE90.

Ag/MoO3-Pd-mediated gasochromic reaction: An efficient dual-mode photoelectrochemical and photothermal immunoassay.

Herein, we presented a dual-readout gasochromic immunosensing platform for accurate and sensitive detection of carcinoembryonic antigen (CEA) based on Ag-doped/Pd nanoparticles loaded MoO3 nanorods (Ag/MoO3-Pd). Initially, the presence of analyte CEA would prompt the formation of sandwich-type immunoreaction, accompanied by the introduction of Pt NPs labeled on detection antibody. Upon the addition of NH3BH3, the product hydrogen (H2) will interact with Ag/MoO3-Pd as a bridge between the sensing interface and the biological assembly platform. Both photocurrent and temperature signals can serve as readouts due to the significantly increased PEC performance and enhanced photothermal conversion capability of H-Ag/MoO3-Pd (the product of Ag/MoO3-Pd react with H2) compared to Ag/MoO3-Pd. In addition, the DFT results show that the band gap of Ag/MoO3-Pd becomes narrower after the reaction with H2, thus improving the utilization of light, which theoretically explains the internal mechanism of gas sensing reaction. Under optimal conditions, the designed immunosensing platform showed good sensitivity for CEA detection with the limit of detection (LOD) of 26 pg mL-1 (photoelectrochemical mode) and 98 pg mL-1 (photothermal mode). This work not only presents the possible reaction mechanism of Ag/MoO3-Pd and H2, but also creatively applicate it in photothermal biosensors that give a new path for devising dual-readout immunosensor.

Bio-inspired nanozyme with ultra-thin Fe-Bi2O2S nanosheets for in-situ amplified photoelectrochemical immunoassay of cancer-related protein.

A Fe-loaded Bi2O2S nanosheet photoanode serving as photoelectric biomonitoring platform for the detection of prostate-specific antigen (PSA) using biologically inspired prussian nanoparticle (PB)-catalyzed biocatalytic precipitation strategy was developed. Primarily, the signal probe PB-mAb2 obtained by electrostatic adsorption was immobilized on a microplate in the presence of target PSA, and 4-chloro-1-naphthol (4-CN) was oxidized to benzo-4-chloro-hexadienone (4-CD) with the assistance of exogenous hydrogen peroxide, which was generated by a large number of hydroxyl radicals catalyzed by PB. The generated 4-CD showed strongly low conductivity characteristics to burst the photocurrent of highly photoactive Fe-Bi2O2S photoanode. The split incubation reaction could be suitable for high volume and low-cost rapid detection. A dynamic response range of 0.1-100 ng mL-1 with a limit of detection of 34.2 pg mL-1 was achieved with the sensor based on a photoelectric sensing platform and a biomimetic catalytic precipitation reaction. Equally important, the sensor also showed good potential in the detection of real samples compared to commercially available ELISA kits. In conclusion, this work provides a fresh scheme for the development of sensitive biosensors through a bio-inspired catalytic strategy of versatility and a photoanode coupling with high photoelectric activity.

Optimal Prehospital Crystalloid Resuscitation Volume in Trauma Patients at Risk for Hemorrhagic Shock.

BACKGROUND: Prehospital resuscitation guidelines vary widely, and blood products, although likely superior, are not available for most patients in the prehospital setting. Our objective was to determine the prehospital crystalloid volume associated with the lowest mortality among patients in hemorrhagic shock. STUDY DESIGN: This is a secondary analysis of the Prehospital Air Medical Plasma trial. Injured patients from the scene with hypotension and tachycardia or severe hypotension were included. Segmented regression and generalized additive models were used to evaluate nonlinear effects of prehospital crystalloid volume on 24-hour mortality. Logistic regression evaluated the association between risk-adjusted mortality and prehospital crystalloid volume ranges to identify optimal target volumes. Inverse propensity weighting was performed to account for patient heterogeneity. RESULTS: There were 405 patients included. Segmented regression suggested the nadir of 24-hour mortality lay within 377 to 1,419 mL prehospital crystalloid. Generalized additive models suggested the nadir of 24-hour mortality lay within 242 to 1,333 mL prehospital crystalloid. A clinically operationalized range of 250 to 1,250 mL was selected based on these findings. Odds of 24-hour mortality were higher for patients receiving less than 250 mL (adjusted odds ratio [aOR] 2.46; 95% CI 1.31 to 4.83; p = 0.007) and greater than 1,250 mL (aOR 2.57; 95% CI 1.24 to 5.45; p = 0.012) compared with 250 to 1,250 mL. Propensity-weighted regression similarly demonstrated odds of 24-hour mortality were higher for patients receiving less than 250 mL (aOR 2.62; 95% CI 1.34 to 5.12; p = 0.005) and greater than 1,250 mL (aOR 2.93; 95% CI 1.36 to 6.29; p = 0.006) compared with 250 to 1,250 mL. CONCLUSIONS: Prehospital crystalloid volumes between 250 and 1,250 mL are associated with lower mortality compared with lower or higher volumes. Further work to validate these finding may provide practical volume targets for prehospital crystalloid resuscitation.

Smartphone-based photoelectrochemical immunoassay of prostate-specific antigen based on Co-doped Bi2O2S nanosheets.

Portable and on-site detection of target biomarker is of great significance in early diagnosis of diseases. Herein, we designed a portable smartphone-based PEC immunoassay platform to detect prostate specific antigen (PSA) adopting Co-doped Bi2O2S nanosheets as photoactive materials. The fast photocurrent response under visible light and excellent electrical transport rate invest Co-doped Bi2O2S with the property of being effectively excited even under a weak light source. Therefore, with the incorporation of a carriable flashlight that act as the excitation light source, disposable screen-printed electrodes, a microelectrochemical workstation and a smartphone that served as control center, point-of-care analytical detection of low-abundance small molecule analytes was successfully realized. Specifically, a sandwich-type immunoreaction was performed using alkaline phosphatase labeled secondary antibody as signal indicator. In the presence of PSA, ascorbic acid as generated through a catalytic reaction, resulting in the enhancement of photocurrent intensity. The photocurrent intensity increased linearly with the logarithm of PSA concentrations ranging from 0.2 to 50 ng mL-1 with a detection limit of 71.2 pg mL-1 (S/N = 3). This system provided an effective method for the construction of portable and miniaturized PEC sensing platform for the application of point-of-care health monitoring.

Direct Trauma Center Access by Helicopter Emergency Medical Services is Associated With Improved Survival After Severe Injury.

OBJECTIVE: Evaluate the association of survival with helicopter transport directly to a trauma center compared with ground transport to a non-trauma center (NTC) and subsequent transfer. SUMMARY BACKGROUND DATA: Helicopter transport improves survival after injury. One potential mechanism is direct transport to a trauma center when the patient would otherwise be transported to an NTC for subsequent transfer. METHODS: Scene patients 16 years and above with positive physiological or anatomic triage criteria within PTOS 2000-2017 were included. Patients transported directly to level I/II trauma centers by helicopter were compared with patients initially transported to an NTC by ground with a subsequent helicopter transfer to a level I/II trauma center. Propensity score matching was used to evaluate the association between direct helicopter transport and survival. Individual triage criteria were evaluated to identify patients most likely to benefit from direct helicopter transport. RESULTS: In all, 36,830 patients were included. Direct helicopter transport was associated with a nearly 2-fold increase in odds of survival compared with NTC ground transport and subsequent transfer by helicopter (aOR 2.78; 95% CI 2.24-3.44, P <0.01). Triage criteria identifying patients with a survival benefit from direct helicopter transport included GCS≤13 (1.71; 1.22-2.41, P <0.01), hypotension (2.56; 1.39-4.71, P <0.01), abnormal respiratory rate (2.30; 1.36-3.89, P <0.01), paralysis (8.01; 2.03-31.69, P <0.01), hemothorax/pneumothorax (2.34; 1.36-4.05, P <0.01), and multisystem trauma (2.29; 1.08-4.84, P =0.03). CONCLUSIONS: Direct trauma center access is a mechanism driving the survival benefit of helicopter transport. First responders should consider helicopter transport for patients meeting these criteria who would otherwise be transported to an NTC.

Dual-mode colorimetric-photothermal sensing platform of acetylcholinesterase activity based on the peroxidase-like activity of Fe-N-C nanozyme.

Sensors based on colorimetry, fluorescence, and electrochemistry have been widely employed to detect acetylcholinesterase and its inhibitors, however, there are only a minority of strategies for AChE detection based on photothermal method. This work reports a versatile dual-mode colorimetric and photothermal biosensing platform for acetylcholinesterase (AChE) detection and its inhibitor (paraoxon-ethyl, a model of AChE inhibitors) monitor based on Fe-N-C/H2O2/3,3',5,5'-tetramethylbenzidine (TMB) system. The Fe-N-C with abundant active Fe-Nx sites shows outstanding peroxidase-mimicking activity and can be used to promote the generation of •OH by H2O2 to oxidize TMB. However, the introduction of mercapto molecules tending to coordinate with metal atoms result in the block of action site in Fe-N-C, thereby decrease its peroxidase-mimetic activity. The designed biosensor principle is based on the block of active sites of Fe-N-C by thiocholine (TCh, one kind of mercapto molecules) that can be produced by acetylthiocholine (ATCh) in the presence of AChE. Under optimum conditions, the limit of detection (LOD) for AChE activity is 1.9 mU mL-1 (colorimetric) and 2.2 mU mL-1 (photothermal), while for paraoxon-ethyl is 0.012 µg mL-1 (colorimetric) and 0.013 µg mL-1 (photothermal), respectively. The assay we proposed not only can be designed to monitor AChE detection and its inhibitors, but also can be easily extended for the detection of other biomolecules relate to the generation or consumption of H2O2.

Snowflake-like CdS@ZnIn2S4 heterojunction-based photocatalyst-electrolyte effect: An innovative mode for photoelectrochemical immunoassay.

Exploiting innovative strategies with signal amplification in photoelectrochemical (PEC) biosensing systems to realize sensitive screening of low-abundance proteins has become one of the mainstream research orientations. Herein we reported a new strategy to amplify photocurrent signal employing a photocatalyst-electrolyte effect in alkaline media for the sensitive monitoring of prostate-specific antigen (PSA) using snowflake-liked CdS@ZnIn2S4 heterojunction as photosensitizer. In this strategy, both the band-edge position and surface redox reaction process were subtly altered by modulating the alkalinity of electrolyte. The hydroxyl anions (OH-) from NaOH could be oxidized to hydroxyl radicals (·OH) by the holes in CdS@ZnIn2S4, thus accelerating the scavenging of holes and promoting the photocurrent. Based on the above-mentioned mechanism, a sensitive split-type glucose oxidase-mediated PEC immunosensor for PSA detection was fabricated. Upon target PSA introduction, the glucose acid was generated through the sandwich-type immunoreaction to affect the alkalinity of PEC detection environment, thereby suppressing the photocurrent intensity. The CdS@ZnIn2S4-based PEC immunosensor exhibited satisfactory photocurrent responses with a good linear range of 0.04-40 ng mL-1 at a limit of detection of 14 pg mL-1. Significantly, this research not only introduces an effective strategy to detect PSA with good sensitivity and specificity, but also provides a new insight to amplify the signal by regulating the electrolyte.

In2O3/CdIn2S4 heterojunction-based photoelectrochemical immunoassay of carcinoembryonic antigen with enzymatic biocatalytic precipitation for signal amplification.

This work reported a split-type photoelectrochemical (PEC) immunoassay for the detection of carcinoembryonic antigen (CEA) based on target-induced biocatalytic precipitation (BCP) by using In2O3/CdIn2S4 heterojunctions as the photosensitizers. The synthesized In2O3/CdIn2S4 heterojunctions improved the efficiency of charge separation and shortened the electron convey path to enhance the photocurrent, thus exhibiting high conductivity and low complexation rates of photogenerated electrons and holes. In the presence of CEA, horseradish peroxidase (HRP) catalyzed 4-chloro-1-naphthol (4-CN) to produce benzo-4-chloro-hexadienone (4-CD) through H2O2. Then, 4-CD was deposited onto the surface of In2O3/CdIn2S4 to reduce the photocurrent and realized the signal amplification. The PEC immunoassay revealed an excellent photocurrent toward target CEA within a wide range of 0.01-50 ng mL-1 at a low limit of detection of 2.8 pg mL-1 under the optimum conditions. Multiple switching light excitation tests demonstrated the good reliability and stability of the fabricated PEC biosensor. The accuracy was acceptable in comparison with human CEA enzyme-linked immunosorbent assay (ELISA) kit.