Enhanced Predictability of Urea Crystallization by an Optimized Laser Repetition Rate.

Laser-induced crystallization is a novel alternative to classical methods for crystallizing organic molecules but requires a judicious choice of experimental parameters for the onset of crystallization to be predictable. This study investigated the impact of the laser repetition rate on the time delay from the start of the pulsed laser illumination to the initiation of crystallization, the so-called induction time. A supersaturated urea solution was irradiated with near-infrared (λ = 1030 nm) laser pulses of pulse duration τ = 5 ps at a pulse energy of approximately E = 340 µJ while varying the repetition rate from 10 to 20,000 Hz. The optimal rate discovered ranged from 500 Hz to 1 kHz, quantified by the measured induction time (median 2-5 s) and the mean probability of inducing a successful crystallization event (5 × 10-2%). For higher repetition rates (5-20 kHz), the mean probability dropped to 3 × 10-3%. The reduced efficiency at high repetition rates is likely due to an interaction between an existing thermocavitation bubble and subsequent pulses. These results suggest that an optimized pulse repetition rate can be a means to gain further control over the laser-induced crystallization process.

Determining Structures of Layer-by-Layer Spin-Coated Zinc Dicarboxylate-Based Metal-Organic Thin Films.

Thin films of crystalline solids with substantial free volume from organic chromophores and metal secondary building units (SBUs) are promising for engineering new optoelectronic properties through control of interchromophore coupling. Zn-based SBUs are especially relevant in this case because they avoid quenching the chromophore's luminescence. We find that layer-by-layer spin-coating using Zn acetate dihydrate and benzene-1,4-dicarboxylic acid (H2BDC) and biphenyl-4,4'-dicarboxylic acid (H2BPDC) linkers easily produces crystalline thin films. However, analysis of the grazing-incidence wide-angle X-ray scattering (GIWAXS) data reveals the structures of these films vary significantly with the linker, and metal-to-linker molar ratio used for fabrication. Under equimolar conditions, H2BPDC creates a type of structure like that proposed for SURMOF-2, whereas H2BDC generates a different metal-hydroxide-organic framework. Large excess of Zn2+ ions causes the growth of layered zinc hydroxides, irrespective of the linker used. Density functional theory (DFT) calculations provide structural models with minimum total energy that are consistent with the experimentally observed diffractograms. In the broader sense, this work illustrates the importance in this field of careful structural determination, e.g., by utilizing GIWAXS and DFT simulations to determine the structure of the obtained crystalline metal-organic thin films, so properties can be rationally engineered and explained.

Epidemiology of prehospital emergency calls according to patient transport decision in a middle eastern emergency care environment: Retrospective cohort-based.

Background and Aim: Though emergency medical services (EMS) respond to all types of emergency calls, they do not always result in the patient being transported to the hospital. This study aimed to explore the determinants influencing emergency call-response-based conveyance decisions in a Middle Eastern ambulance service. Methods: This retrospective quantitative analysis of 93,712 emergency calls to the Hamad Medical Corporation Ambulance Service (HMCAS) between January 1 and May 31, 2023, obtained from the HMCAS electronic system, was analyzed to determine pertinent variables. Sociodemographic, emergency dispatch-related, clinical, and miscellaneous predictors were analyzed. Descriptive, bivariate, ridge logistic regression, and combination analyses were evaluated. Results: 23.95% (N = 21,194) and 76.05% (N = 67,285) resulted in patient nontransport and transportation, respectively. Sociodemographic analysis revealed that males predominantly activated EMS resources, and 60% of males (n = 12,687) were not transported, whilst 65% of females (n = 44,053) were transported. South Asians represented a significant proportion of the transported patients (36%, n = 24,007). "Home" emerged as the primary emergency location (56%, n = 37,725). Bivariate analysis revealed significant associations across several variables, though multicollinearity was identified as a challenge. Ridge regression analysis underscored the role of certain predictors, such as missing provisional diagnoses, in transportation decisions. The upset plot shows that hypertension and diabetes mellitus were the most common combinations in both groups. Conclusions: This study highlights the nuanced complexities governing conveyance decisions. By unveiling patterns such as male predominance, which reflects Qatar's expatriate population, and specific temporal EMS activity peaks, this study accentuates the importance of holistic patient assessment that transcends medical histories.

Exploring factors influencing time from dispatch to unit availability according to the transport decision in the pre-hospital setting: an exploratory study.

BACKGROUND: Efficient resource distribution is important. Despite extensive research on response timings within ambulance services, nuances of time from unit dispatch to becoming available still need to be explored. This study aimed to identify the determinants of the duration between ambulance dispatch and readiness to respond to the next case according to the patients' transport decisions. METHODS: Time from ambulance dispatch to availability (TDA) analysis according to the patients' transport decision (Transport versus Non-Transport) was conducted using R-Studio™ for a data set of 93,712 emergency calls managed by a Middle Eastern ambulance service from January to May 2023. Log-transformed Hazard Ratios (HR) were examined across diverse parameters. A Cox regression model was utilised to determine the influence of variables on TDA. Kaplan-Meier curves discerned potential variances in the time elapsed for both cohorts based on demographics and clinical indicators. A competing risk analysis assessed the probabilities of distinct outcomes occurring. RESULTS: The median duration of elapsed TDA was 173 min for the transported patients and 73 min for those not transported. The HR unveiled Significant associations in various demographic variables. The Kaplan-Meier curves revealed variances in TDA across different nationalities and age categories. In the competing risk analysis, the 'Not Transported' group demonstrated a higher incidence of prolonged TDA than the 'Transported' group at specified time points. CONCLUSIONS: Exploring TDA offers a novel perspective on ambulance services' efficiency. Though promising, the findings necessitate further exploration across diverse settings, ensuring broader applicability. Future research should consider a comprehensive range of variables to fully harness the utility of this period as a metric for healthcare excellence.

Behavioral Motor Performance.

The human sensorimotor control system has exceptional abilities to perform skillful actions. We easily switch between strenuous tasks that involve brute force, such as lifting a heavy sewing machine, and delicate movements such as threading a needle in the same machine. Using a structure with different control architectures, the motor system is capable of updating its ability to perform through our daily interaction with the fluctuating environment. However, there are issues that make this a difficult computational problem for the brain to solve. The brain needs to control a nonlinear, nonstationary neuromuscular system, with redundant and occasionally undesired degrees of freedom, in an uncertain environment using a body in which information transmission is subject to delays and noise. To gain insight into the mechanisms of motor control, here we survey movement laws and invariances that shape our everyday motion. We then examine the major solutions to each of these problems in the three parts of the sensorimotor control system, sensing, planning, and acting. We focus on how the sensory system, the control architectures, and the structure and operation of the muscles serve as complementary mechanisms to overcome deviations and disturbances to motor behavior and give rise to skillful motor performance. We conclude with possible future research directions based on suggested links between the operation of the sensorimotor system across the movement stages. © 2024 American Physiological Society. Compr Physiol 14:5179-5224, 2024.

Trigger tool-based description of adverse events in helicopter emergency medical services in Qatar.

INTRODUCTION: Adverse events (AEs) in helicopter emergency medical services (HEMS) remain poorly reported, despite the potential for harm to occur. The trigger tool (TT) represents a novel approach to AE detection in healthcare. The aim of this study was to retrospectively describe the frequency of AEs and their proximal causes (PCs) in Qatar HEMS. METHODS: Using the Pittsburgh Adverse Event Tool to identify AEs in HEMS, we retrospectively analysed 804 records within an existing AE TT database (21-month period). We calculated outcome measures for triggers, AEs and harm per 100 patient encounters, plotted measures on statistical process control charts, and conducted a multivariate analysis to report harm associations. RESULTS: We identified 883 triggers in 536 patients, with a rate of 1.1 triggers per patient encounter, where 81.2% had documentation errors (n=436). An AE and harm rate of 27.7% and 3.5%, respectively, was realised. The leading PC was actions by HEMS Crew (81.6%; n=182). The majority of harm (57.1%) stemmed from the intervention and medication triggers (n=16), where deviation from standard of care was common (37.9%; n=11). Age and diagnosis-adjusted odds were significant in the patient condition (6.50; 95% CI 1.71 to 24.67; p=0.01) and interventional (11.85; 95% CI 1.36 to 102.92; p=0.03) trigger groupings, while age and diagnosis had no effect on harm. CONCLUSION: The TT methodology is a robust, reliable and valid means of AE detection in the HEMS domain. While an AE rate of 27.7% is high, more research is required to understand prehospital clinical decision-making and reasons for guideline deviance. Furthermore, focused quality improvement initiatives to reduce AEs and documentation errors should also be addressed in future research.

High Quantum Yield Shortwave Infrared Luminescent Tracers for Improved Sorting of Plastic Waste.

More complete recycling of plastic waste is possible only if new technologies that go beyond state-of-the-art near-infrared (NIR) sorting are developed. For example, tracer-based sorting is a new technology that explores the upconversion or down-shift luminescence of special tracers based on inorganic materials codoped with lanthanide ions. Specifically, down-shift tracers emit in the shortwave infrared (SWIR) spectral range and can be detected using a SWIR camera preinstalled in a state-of-the-art sorting machine for NIR sorting. In this study, we synthesized a very efficient SWIR tracer by codoping Li3Ba2Gd3 (MoO4)8 with Yb3+ and Er3+, where Yb3+ is a synthesizer ion (excited near 976 nm) and Er3+ emits near 1550 nm. Fine-tuning of the doping concentration resulted in a tracer (Li3Ba2Gd(3-x-y)(MoO4)8:xYb3+, yEr3+, where x = 0.2 and y = 0.4) with a high photoluminescence quantum yield for 1550 nm emission of 70% (using 976 nm excitation). This tracer was used to mark plastic objects. When the object was illuminated by a halogen lamp and a 976 nm laser, the three parts could be easily distinguished based on reflectance and luminescence spectra in the SWIR range: a plastic bottle made of polyethylene terephthalate, a bottle cap made of high-density polyethylene, and a label made of the tracer Li3Ba2Gd3(MoO4)8:Yb3+, Er3+. Importantly, the use of the tracer in sorting may require only the installation of a 976 nm laser in a state-of-the-art NIR sorting system.

Solar-pumped fiber laser using a solid-state luminescent solar collector.

We have developed a fully planar solar-pumped fiber laser using a solid-state luminescent solar collector (LSC). This laser does not use any focusing device, such as a lens or mirror; thus, it can lase without tracking the sun. Our developed device with an aperture of 30 cm emits 15 mW, corresponding to an optical-to-optical conversion efficiency of 0.023% and a collection efficiency of 0.21 W/m2. A 12-fold improvement over a previously developed liquid LSC is achieved by combining the total internal reflection of the solid-state LSC with dielectric multilayer mirrors. The observed laser power is in good agreement with that predicted via numerical simulation, demonstrating the effectiveness of our proposed method.

Tunable J-type aggregation of silicon phthalocyanines in a surface-anchored metal-organic framework thin film.

Organic chromophores and semiconductors, like anthracene, pentacene, perylene, and porphyrin, are prone to aggregation, and their packing in the solid state is often hard to predict and difficult to control. As the condensed phase structures of these chromophores and semiconductors are of crucial importance for their optoelectronic functionality, strategies to control their assembly and provide new structural motifs are important. One such approach uses metal-organic frameworks (MOFs); the organic chromophore is converted into a linker and connected by metal ions or nodes. The spatial arrangement of the organic linkers can be well-defined in a MOF, and hence optoelectronic functions can be adjusted accordingly. We have used such a strategy to assemble a phthalocyanine chromophore and illustrated that the electronic inter-phthalocyanine coupling can be rationally tuned by introducing bulky side grounds to increase steric hindrance. We have designed new phthalocyanine linkers and using a layer-by-layer liquid-phase epitaxy strategy thin films of phthalocyanine-based MOFs have been fabricated and their photophysical properties explored. It was found that increasing the steric hindrance around the phthalocyanine reduced the effect of J-aggregation in the thin film structures.

In silico prediction of acute chemical toxicity of biocides in marine crustaceans using machine learning.

Biocides are a heterogeneous group of chemical substances intended to control the growth or kill undesired organisms. Due to their extensive use, they enter marine ecosystems via non-point sources and may pose a threat to ecologically important non-target organisms. Consequently, industries and regulatory agencies have recognized the ecotoxicological hazard potential of biocides. However, the prediction of biocide chemical toxicity on marine crustaceans has not been previously evaluated. This study aims to provide in silico models capable of classifying structurally diverse biocidal chemicals into different toxicity categories and predict acute chemical toxicity (LC50) in marine crustaceans using a set of calculated 2D molecular descriptors. The models were built following the guidelines recommended by the OECD (Organization for Economic Cooperation and Development) and validated through stringent processes (internal and external validation). Six machine learning (ML) models were built and compared (linear regression: LR; support vector machine: SVM; random forest: RF; feed-forward backpropagation-based artificial neural network: ANN; decision trees: DT and naïve Bayes: NB) for regression and classification analysis to predict toxicities. All the models displayed encouraging results with high generalisability: the feed-forward-based backpropagation method showed the best results with determination coefficient R2 values of 0.82 and 0.94, respectively, for training set (TS) and validation set (VS). For classification-based modelling, the DT model performed the best with an accuracy (ACC) of 100 % and an area under curve (AUC) value of 1 for both TS and VS. These models showed the potential to replace animal testing for the chemical hazard assessment of untested biocides if they fall within the applicability domain of the proposed models. In general, the models are highly interpretable and robust, with good predictive performance. The models also displayed a trend indicating that toxicity is largely influenced by factors such as lipophilicity, branching, non-polar bonding and saturation of molecules.

Prior Movement of One Arm Facilitates Motor Adaptation in the Other.

Many movements in daily life are embedded in motion sequences that involve more than one limb, demanding the motor system to monitor and control different body parts in quick succession. During such movements, systematic changes in the environment or the body might require motor adaptation of specific segments. However, previous motor adaptation research has focused primarily on motion sequences produced by a single limb, or on simultaneous movements of several limbs. For example, adaptation to opposing force fields is possible in unimanual reaching tasks when the direction of a prior or subsequent movement is predictive of force field direction. It is unclear, however, whether multilimb sequences can support motor adaptation processes in a similar way. In the present study (38 females, 38 males), we investigated whether reaches can be adapted to different force fields in a bimanual motor sequence when the information about the perturbation is associated with the prior movement direction of the other arm. In addition, we examined whether prior perceptual (visual or proprioceptive) feedback of the opposite arm contributes to force field-specific motor adaptation. Our key finding is that only active participation in the bimanual sequential task supports pronounced adaptation. This result suggests that active segments in bimanual motion sequences are linked across limbs. If there is a consistent association between movement kinematics of the linked and goal movement, the learning process of the goal movement can be facilitated. More generally, if motion sequences are repeated often, prior segments can evoke specific adjustments of subsequent movements.SIGNIFICANCE STATEMENT Movements in a limb's motion sequence can be adjusted based on linked movements. A prerequisite is that kinematics of the linked movements correctly predict which adjustments are needed. We show that use of kinematic information to improve performance is even possible when a prior linked movement is performed with a different limb. For example, a skilled juggler might have learned how to correctly adjust his catching movement of the left hand when the right hand performed a throwing action in a specific way. Linkage is possibly a key mechanism of the human motor system for learning complex bimanual skills. Our study emphasizes that learning of specific movements should not be studied in isolation but within their motor sequence context.

Absolute quantum yield for understanding upconversion and downshift luminescence in PbF2:Er3+,Yb3+ crystals.

The search for new materials capable of efficient upconversion continues to attract attention. In this work, a comprehensive study of the upconversion luminescence in PbF2:Er3+,Yb3+ crystals with different concentrations of Yb3+ ions in the range of 2 to 7.5 mol% (Er3+ concentration was fixed at 2 mol%) was carried out. The highest value of upconversion quantum yield (ϕUC) 5.9% (at 350 W cm-2) was found in the PbF2 crystal doped with 2 mol% Er3+ and 3 mol% Yb3+. Since it is not always easy to directly measure ϕUC and estimate the related key figure of merit parameter, saturated photoluminescence quantum yield (ϕUCsat), a method to reliably predict ϕUCsat can be useful. Judd-Ofelt theory provides a convenient way to determine the radiative lifetimes of the excited states of rare-earth ions based on absorption measurements. When the luminescence decay times after direct excitation of a level are also measured, ϕUCsat for that level can be calculated. This approach is tested on a series of PbF2:Er3+,Yb3+ crystals. Good agreement between the estimates obtained as above and the directly experimentally measured ϕUCsat values is demonstrated. In addition, three methods of Judd-Ofelt calculations on powder samples were tested and the results were compared with Judd-Ofelt calculations on single crystals, which served as the source of the powder samples. Taken together, the results presented in our work for PbF2:Er3+,Yb3+ crystals contribute to a better understanding of the UC phenomena and provide a reference data set for the use of UC materials in practical applications.

Enhancement of Amplified Spontaneous Emission by Electric Field in CsPbBr3 Perovskites.

Perovskite gain materials can sustain continuous-wave lasing at room-temperature. A first step toward the unachieved goal of electrically excited lasing would be an improvement in gain when electrical stimulation is added to the optical. However, to date, electrical stimulation supplementing optical has reduced gain performance. We find that amplified spontaneous emission (ASE) in a CsPbBr3 perovskite light-emitting diode (LED) held under invariant subthreshold optical excitation can be turned on/off by the addition/removal of an electric field. A positive bias voltage leads to a factor of 3 reduction in the optical ASE threshold, the cause of which can be attributed to an enhancement of the radiative rate. The slow components (10 s time scale) of the modulation in the photoluminescence and ASE when the voltage is changed suggest that the relocation of mobile ions trigger the increased radiative rate and observed lowering of ASE thresholds.

Limitation of room temperature phosphorescence efficiency in metal organic frameworks due to triplet-triplet annihilation.

The effect of triplet-triplet annihilation (TTA) on the room-temperature phosphorescence (RTP) in metal-organic frameworks (MOFs) is studied in benchmark RTP MOFs based on Zn metal centers and isophthalic or terephthalic acid linkers (ZnIPA and ZnTPA). The ratio of RTP to singlet fluorescence is observed to decrease with increasing excitation power density. Explicitly, in ZnIPA the ratio of the RTP to fluorescence is 0.58 at 1.04 mW cm-2, but only 0.42 at (the still modest) 52.6 mW cm-2. The decrease in ratio is due to the reduction of RTP efficiency at higher excitation due to TTA. The density of triplet states increases at higher excitation power densities, allowing triplets to diffuse far enough during their long lifetime to meet another triplet and annihilate. On the other hand, the shorter-lived singlet species can never meet an annihilate. Therefore, the singlet fluorescence scales linearly with excitation power density whereas the RTP scales sub-linearly. Equivalently, the efficiency of fluorescence is unaffected by excitation power density but the efficiency of RTP is significantly reduced at higher excitation power density due to TTA. Interestingly, in time-resolved measurements, the fraction of fast decay increases but the lifetime of long tail of the RTP remains unaffected by excitation power density. This may be due to the confinement of triplets to individual grains, leading decay to be faster until there is only one triplet per grain left. Subsequently, the remaining "lone triplets" decay with the unchanging rate expressed by the long tail. These results increase the understanding of RTP in MOFs by explicitly showing the importance of TTA in determining the (excitation power density dependent) efficiency of RTP. Also, for applications in optical sensing, these results suggest that a method based on long tail lifetime of the RTP is preferable to a ratiometric approach as the former will not be affected by variation in excitation power density whereas the latter will be.

A Review of MEMS Vibrating Gyroscopes and Their Reliability Issues in Harsh Environments.

Micro-electromechanical systems (MEMS) vibrating gyroscopes have gained a lot of attention over the last two decades because of their low power consumption, easy integration, and low fabrication cost. The usage of the gyroscope equipped with an inertial measurement unit has increased tremendously, with applications ranging from household devices to smart electronics to military equipment. However, reliability issues are still a concern when operating this inertial sensor in harsh environments, such as to control the movement and alignment of mini-satellites in space, tracking firefighters at an elevated temperature, and assisting aircraft navigation in gusty turbulent air. This review paper focuses on the key fundamentals of the MEMS vibrating gyroscopes, first discussing popular designs including the tuning fork, gimbal, vibrating ring, and multi-axis gyroscopes. It further investigates how bias stability, angle random walk, scale factor, and other performance parameters are affected in harsh environments and then discusses the reliability issues of the gyroscopes.

Rescue Activity of a Civilian Helicopter Emergency Medical Service in the Western Cape, South Africa: A 5-Year Retrospective Review.

INTRODUCTION: Helicopter search and rescue (SAR) in Africa is conducted primarily by military organizations. Since 2002, the Western Cape of South Africa has had a dedicated contracted civilian helicopter emergency medical service (HEMS) conducting air ambulance, terrestrial, and aquatic rescue. To our knowledge, this is the first description of the operations of an African helicopter rescue service. METHODS: A 5-y retrospective review of the terrestrial and aquatic helicopter rescue activity of a civilian-operated HEMS in the Western Cape, South Africa, from January 1, 2012 through December 31, 2016, was conducted. Data were extracted from the organization's operational database, aviation documents, rescue reports, and patient care records. Patient demographics and activity at the time of rescue, temporal and geographical distribution, crewing compositions, patient injury, triage, clinical interventions, and rescue techniques were analyzed. RESULTS: A total of 581 SAR missions were conducted, of which 451 were terrestrial and 130 were aquatic rescues. The highest volume of rescues was conducted within the urban Cape Peninsula. Hoisting using a rescue harness was the most common rescue technique used. A total of 644 patients were rescued, with no or minor injuries representing 79% of the sample. Trauma (33%, 196/644) was the most common medical reason for rescue, with lower limb trauma predominant (15%, 90/644). The most common clinical interventions performed were intravenous access (n=108, 24%), spinal immobilization (n=92, 21%), splinting (n=76, 17%), and analgesia administration (n=58, 13%). CONCLUSIONS: The rescue techniques utilized are similar to those described in high-income settings. Uninjured patients comprised the majority of the patients rescued.

Assessing reactive violence using Immersive Virtual Reality.

Assessing levels of aggression-specifically reactive violence-has been a challenge in the past, since individuals might be reluctant to self-report aggressive tendencies. Furthermore, experimental studies often lack ecological validity. Immersive Virtual Reality (IVR) offers a reliable, ethically safe environment, and is the most realistic virtual simulation method currently available. It allows researchers to test participants' aggressive responses to realistic provocations from virtual humans. In the current study, 116 participants completed our IVR aggression task, in which they encountered avatars who would either approach them in a friendly or provocative fashion. Participants had the option either to shake hands or hit the virtual human, in congruent and incongruent trials. In congruent trials, the response required of the participant matched the approach with the avatar (e.g., hitting the avatar after provocation). In incongruent trials there was a mismatch between the avatars approach and the participants required response. Congruent trials were designed to measure the immediate reaction towards the virtual human, and incongruent trials to assess response inhibition. Additionally, participants also completed traditional questionnaire-based measures of aggression, as well as reporting their past violent behaviour. We found that the immediate aggressive responses in the IVR task correlated with the established questionnaire measures (convergent validity), and we found that the IVR task was a stronger predictor of past violent behaviour than traditional measures (discriminant validity). This suggests that IVR might be an effective way to assess aggressive behaviour in a more indirect, but realistic manner, than current questionnaire assessment.

Dual-color dynamic anti-counterfeiting labels with persistent emission after visible excitation allowing smartphone authentication.

A significant impediment to the deployment of anti-counterfeiting technologies is the reliance on specialized hardware. Here, anti-counterfeiting labels are developed that are both excited and detected using a smartphone. The persistent luminescence pattern and color changes on the timescale of hundreds of milliseconds to seconds. The labels can be authenticated by comparing still images from the red and green channels of video acquired at known times after flashlight excitation against expected reference patterns. The labels are based on a green-emitting SrAl2O4: Eu2+,Dy3+ (SAED), and red-emitting CaS:Eu2+ phosphors whose lifetimes are varied: (i) for SAED from 0.5 to 11.7 s by annealing the commercial material in air; and (ii) CaS:Eu2+ from 0.1 to 0.6 s by varying the dopant concentration. Examples of anti-counterfeiting labels exhibiting changing emission patterns and colors on a seven-segment display, barcode, and emoji are demonstrated. These results demonstrate that phosphors with visible absorption and tunable persistent luminescence lifetimes on the order of hundreds of milliseconds to seconds are attractive for anti-counterfeiting applications as they allow authentication to be performed using only a smartphone. Further development should allow richer color shifts and enhancement of security by embedding further covert anti-counterfeiting features.

Retrospective identification of medication related adverse events in the emergency medical services through the analysis of a patient safety register.

Adverse drug events encompass a wide range of potential unintended and harmful events, from adverse drug reactions to medication errors, many of which in retrospect, are considered preventable. However, the primary challenge towards reducing their burden lies in consistently identifying and monitoring these occurrences, a challenge faced across the spectrum of healthcare, including the emergency medical services. The aim of this study was to identify and describe medication related adverse events (AEs) in the out-of-hospital setting. The medication components of a dedicated patient safety register were analysed and described for the period Jan 2017-Sept 2020. Univariate descriptive analysis was used to summarize and report on basic case and patient demographics, intervention related AEs, medication related AEs, and AE severity. Multivariable logistic regression was used to assess the odds of AE severity, by AE type. A total of 3475 patient records were assessed where 161 individual medication AEs were found in 150 (4.32%), 12 of which were categorised as harmful. Failure to provide a required medication was found to be the most common error (1.67%), followed by the administration of medications outside of prescribed practice guidelines (1.18%). There was evidence to suggest a 63% increase in crude odds of any AE severity [OR 1.63 (95% CI 1.03-2.6), p = 0.035] with the medication only AEs when compared to the intervention only AEs. Prehospital medication related adverse events remain a significant threat to patient safety in this setting and warrant greater widespread attention and future identification of strategies aimed at their reduction.

BODIPY-pyrene donor-acceptor sensitizers for triplet-triplet annihilation upconversion: the impact of the BODIPY-core on upconversion efficiency.

Triplet-triplet annihilation upconversion (TTA-UC) is an important type of optical process with applications in biophotonics, solar energy harvesting and photochemistry. In most of the TTA-UC systems, the formation of triplet excited states takes place via spin-orbital interactions promoted by heavy atoms. Given the crucial role of heavy atoms (especially noble metals, such as Pd and Pt) in promoting intersystem crossing (ISC) and, therefore, in production of UC luminescence, the feasibility of using more readily available and inexpensive sensitizers without heavy atoms remains a challenge. Here, we investigated sensitization of TTA-UC using BODIPY-pyrene heavy-atom-free donor-acceptor dyads with different numbers of alkyl groups in the BODIPY scaffold. The molecules with four and six alkyl groups are unable to sensitize TTA-UC in the investigated solvents (tetrahydrofuran (THF) and dichloromethane (DCM)) due to negligible ISC. In contrast, the dyad with two methyl groups in the BODIPY scaffold and the dyad with unsubstituted BODIPY demonstrate efficient intersystem crossing (ISC) of 49-58%, resulting in TTA-UC with quantum yields of 4.7% and 6.9%, respectively. The analysis of the elementary steps of the TTA-UC process indicates that heavy-atom-free donor-acceptor dyads are less effective than their noble metal counterparts, but may equal them in the future if the right combination of solvent, donor-acceptor sensitizer structure, and new luminescent molecules as TTA-UC emitters can be found.