Titanium:sapphire-on-insulator integrated lasers and amplifiers.

Titanium:sapphire (Ti:sapphire) lasers have been essential for advancing fundamental research and technological applications, including the development of the optical frequency comb1, two-photon microscopy2 and experimental quantum optics3,4. Ti:sapphire lasers are unmatched in bandwidth and tuning range, yet their use is restricted because of their large size, cost and need for high optical pump powers5. Here we demonstrate a monocrystalline titanium:sapphire-on-insulator (Ti:SaOI) photonics platform that enables dramatic miniaturization, cost reduction and scalability of Ti:sapphire technology. First, through the fabrication of low-loss whispering-gallery-mode resonators, we realize a Ti:sapphire laser operating with an ultralow, sub-milliwatt lasing threshold. Then, through orders-of-magnitude improvement in mode confinement in Ti:SaOI waveguides, we realize an integrated solid-state (that is, non-semiconductor) optical amplifier operating below 1 µm. We demonstrate unprecedented distortion-free amplification of picosecond pulses to peak powers reaching 1.0 kW. Finally, we demonstrate a tunable integrated Ti:sapphire laser, which can be pumped with low-cost, miniature, off-the-shelf green laser diodes. This opens the doors to new modalities of Ti:sapphire lasers, such as massively scalable Ti:sapphire laser-array systems for several applications. As a proof-of-concept demonstration, we use a Ti:SaOI laser array as the sole optical control for a cavity quantum electrodynamics experiment with artificial atoms in silicon carbide6. This work is a key step towards the democratization of Ti:sapphire technology through a three-orders-of-magnitude reduction in cost and footprint and introduces solid-state broadband amplification of sub-micron wavelength light.

Photobiomodulation Treatment with a Home-Use Device for COVID-19: A Randomized Controlled Trial for Efficacy and Safety.

Background: Photobiomodulation therapy (PBMT) using devices to deliver red and/or near-infrared light to tissues has shown promising effects in clinical settings for respiratory diseases, including potential benefits in managing symptoms associated with COVID-19. Objective: To determine if at-home self-administered PBMT for patients with COVID-19 is safe and effective. Methods: This was a randomized controlled trial (RCT) carried out at home during the COVID-19 pandemic (September 2020 to August 2021). The treatment group self-administered the Vielight RX Plus PBMT device (635 nm intranasal and 810 nm chest LEDs) and were monitored remotely. Eligible patients scored 4-7 (out of 7) for severity on the Wisconsin Upper Respiratory Symptom Survey (WURSS-44). Patients were randomized equally to Control group receiving standard-of-care (SOC) only or Treatment group receiving SOC plus PBMT. The device was used for 20 min 2X/day for 5 days and, subsequently, once daily for 30 days. The primary end-point was time-to-recovery (days) based on WURSS-44 question 1, "How sick do you feel today?". Subgroup analysis was performed, and Kaplan-Meier and Cox Proportional Hazards analysis were employed. Results: One hundred and ninety-nine eligible patients (18-65 years old) were divided into two subgroups as follows: 136 patients with 0-7 days of symptoms at baseline and 63 patients with 8-12 days of symptoms. Those with 0-7 days of symptoms at baseline recovered significantly faster with PBMT. The median for Treatment group was 18 days [95% confidence interval (CI), 13-20] versus the Control group 21 days (95% CI, 15-28), p = 0.050. The treatment:control hazard ratio was 1.495 (95% CI, 0.996-2.243), p = 0.054. Patients with symptom duration ≥7 days did not show any significant improvement. No deaths or severe adverse events (SAEs) occurred in the Treatment group, whereas there was 1 death and 3 SAEs requiring hospitalization in the Control group. Conclusions: Patients with ≤7 days of COVID-19 symptoms recovered significantly faster with PBMT compared to SOC. Beyond 7 days, PBMT showed no superiority over SOC. Trial Registration: ClinicalTrials.gov NCT04418505.

Distributable, metabolic PET reporting of tuberculosis.

Tuberculosis remains a large global disease burden for which treatment regimens are protracted and monitoring of disease activity difficult. Existing detection methods rely almost exclusively on bacterial culture from sputum which limits sampling to organisms on the pulmonary surface. Advances in monitoring tuberculous lesions have utilized the common glucoside [18F]FDG, yet lack specificity to the causative pathogen Mycobacterium tuberculosis (Mtb) and so do not directly correlate with pathogen viability. Here we show that a close mimic that is also positron-emitting of the non-mammalian Mtb disaccharide trehalose - 2-[18F]fluoro-2-deoxytrehalose ([18F]FDT) - is a mechanism-based reporter of Mycobacteria-selective enzyme activity in vivo. Use of [18F]FDT in the imaging of Mtb in diverse models of disease, including non-human primates, successfully co-opts Mtb-mediated processing of trehalose to allow the specific imaging of TB-associated lesions and to monitor the effects of treatment. A pyrogen-free, direct enzyme-catalyzed process for its radiochemical synthesis allows the ready production of [18F]FDT from the most globally-abundant organic 18F-containing molecule, [18F]FDG. The full, pre-clinical validation of both production method and [18F]FDT now creates a new, bacterium-selective candidate for clinical evaluation. We anticipate that this distributable technology to generate clinical-grade [18F]FDT directly from the widely-available clinical reagent [18F]FDG, without need for either custom-made radioisotope generation or specialist chemical methods and/or facilities, could now usher in global, democratized access to a TB-specific PET tracer.

Effect of Medial Patellofemoral Complex Reconstruction Technique on Patellofemoral Contact Pressure, Contact Area, and Kinematics.

BACKGROUND: Medial patellofemoral ligament (MPFL) reconstruction is considered by many to be the gold standard to treat lateral patellar instability; however, some investigators have reported good clinical results after isolated medial quadriceps tendon-femoral ligament (MQTFL) reconstruction or a combined MPFL/MQTFL reconstruction. A handful of studies have preliminarily investigated the biomechanical consequences of these various medial patellar stabilizing procedures. Despite this, no existing study has included multiple medial patellofemoral complex (MPFC) reconstructions and assessment of lateral patellar translation at distinct flexion angles. HYPOTHESIS: Combined MPFL/MQTFL reconstruction would restore patellofemoral contact areas, forces, and kinematics closest to the native state compared with isolated reconstruction of the MPFL or MQTFL alone. STUDY DESIGN: Controlled laboratory study. METHODS: Ten adult cadaveric knee specimens were prepared and analyzed under 5 different conditions: (1) intact state, (2) transected MPFC, (3) isolated MPFL reconstruction, (4) isolated MQTFL reconstruction, and (5) combined MPFL/MQTFL reconstruction. Patellar tilt, lateral patellar translation, patellofemoral contact forces, and patellofemoral contact areas were measured in each condition from 0° to 80° through simulated knee flexion using a custom servohydraulic load frame with pressure sensor technology and a motion capture system for kinematic data acquisition. RESULTS: The isolated MPFL, isolated MQTFL, and combined MPFL/MQTFL reconstruction conditions produced significantly less lateral patellar tilt compared with the transected MPFC state (P < .05). No statistically significant differences were found when each reconstruction technique was compared with the intact state in patellar tilt, lateral patellar translation, contact forces, and contact areas. CONCLUSION: All 3 reconstruction techniques (isolated MPFL reconstruction, isolated MQTFL reconstruction, and combined MPFL/MQTFL reconstruction) restored native knee kinematics, contact forces, and contact areas without overconstraint. CLINICAL RELEVANCE: Isolated MPFL reconstruction, isolated MQTFL reconstruction, and combined MPFL/MQTFL reconstruction all restore patellofemoral stability comparable with the intact MPFC state without the overconstraint that could be concerning for increasing risk of patellofemoral arthritis.

Selective Defluorination of Trifluoromethyl Substituents by Conformationally Induced Remote Substitution.

The selective reduction of an aromatic trifluoromethyl substituent to a difluoromethyl substituent may be achieved by base-promoted elimination to form a difluoro-p-quinomethide which is trapped by an intramolecular nucleophile. High yields are obtained when the nucleophilic trap entails the conformationally favoured cyclisation of an aminoisobutyric acid (Aib) derivative. The resulting cyclised difluoromethyl-substituted arylimidazolidinone products are readily converted to versatile difluoromethyl-substituted aldehydes by reduction and hydrolysis. Defluorination is successful on a range of benzenoid (both para and ortho CF3-substituted) and heterocyclic substrates. Double defluorination may likewise be achieved sequentially, or in a single step, from an Aib dipeptide derivative.

A measles-vectored vaccine candidate expressing prefusion-stabilized SARS-CoV-2 spike protein brought to phase I/II clinical trials: protection of African green monkeys from COVID-19 disease.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged at the end of 2019 and is responsible for the largest human pandemic in 100 years. Thirty-four vaccines are currently approved for use worldwide, and approximately 67% of the world population has received a complete primary series of one, yet countries are dealing with new waves of infections, variant viruses continue to emerge, and breakthrough infections are frequent secondary to waning immunity. Here, we evaluate a measles virus (MV)-vectored vaccine expressing a stabilized prefusion SARS-CoV-2 spike (S) protein (MV-ATU3-S2PΔF2A; V591) with demonstrated immunogenicity in mouse models (see companion article [J. Brunet, Z. Choucha, M. Gransagne, H. Tabbal, M.-W. Ku et al., J Virol 98:e01693-23, 2024, https://doi.org/10.1128/jvi.01693-23]) in an established African green monkey model of disease. Animals were vaccinated with V591 or the control vaccine (an equivalent MV-vectored vaccine with an irrelevant antigen) intramuscularly using a prime/boost schedule, followed by challenge with an early pandemic isolate of SARS-CoV-2 at 56 days post-vaccination. Pre-challenge, only V591-vaccinated animals developed S-specific antibodies that had virus-neutralizing activity as well as S-specific T cells. Following the challenge, V591-vaccinated animals had lower infectious virus and viral (v) RNA loads in mucosal secretions and stopped shedding virus in these secretions earlier. vRNA loads were lower in these animals in respiratory and gastrointestinal tract tissues at necropsy. This correlated with a lower disease burden in the lungs as quantified by PET/CT at early and late time points post-challenge and by pathological analysis at necropsy.IMPORTANCESevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the largest human pandemic in 100 years. Even though vaccines are currently available, countries are dealing with new waves of infections, variant viruses continue to emerge, breakthrough infections are frequent, and vaccine hesitancy persists. This study uses a safe and effective measles vaccine as a platform for vaccination against SARS-CoV-2. The candidate vaccine was used to vaccinate African green monkeys (AGMs). All vaccinated AGMs developed robust antigen-specific immune responses. After challenge, these AGMs produced less virus in mucosal secretions, for a shorter period, and had a reduced disease burden in the lungs compared to control animals. At necropsy, lower levels of viral RNA were detected in tissue samples from vaccinated animals, and the lungs of these animals lacked the histologic hallmarks of SARS-CoV-2 disease observed exclusively in the control AGMs.

Multicenter integrated analysis of noncoding CRISPRi screens.

The ENCODE Consortium's efforts to annotate noncoding cis-regulatory elements (CREs) have advanced our understanding of gene regulatory landscapes. Pooled, noncoding CRISPR screens offer a systematic approach to investigate cis-regulatory mechanisms. The ENCODE4 Functional Characterization Centers conducted 108 screens in human cell lines, comprising >540,000 perturbations across 24.85 megabases of the genome. Using 332 functionally confirmed CRE-gene links in K562 cells, we established guidelines for screening endogenous noncoding elements with CRISPR interference (CRISPRi), including accurate detection of CREs that exhibit variable, often low, transcriptional effects. Benchmarking five screen analysis tools, we find that CASA produces the most conservative CRE calls and is robust to artifacts of low-specificity single guide RNAs. We uncover a subtle DNA strand bias for CRISPRi in transcribed regions with implications for screen design and analysis. Together, we provide an accessible data resource, predesigned single guide RNAs for targeting 3,275,697 ENCODE SCREEN candidate CREs with CRISPRi and screening guidelines to accelerate functional characterization of the noncoding genome.

Modular, multi-robot integration of laboratories: an autonomous workflow for solid-state chemistry.

Automation can transform productivity in research activities that use liquid handling, such as organic synthesis, but it has made less impact in materials laboratories, which require sample preparation steps and a range of solid-state characterization techniques. For example, powder X-ray diffraction (PXRD) is a key method in materials and pharmaceutical chemistry, but its end-to-end automation is challenging because it involves solid powder handling and sample processing. Here we present a fully autonomous solid-state workflow for PXRD experiments that can match or even surpass manual data quality, encompassing crystal growth, sample preparation, and automated data capture. The workflow involves 12 steps performed by a team of three multipurpose robots, illustrating the power of flexible, modular automation to integrate complex, multitask laboratories.

Development of prehospital emergency care in Singapore.

This review paper describes the development of the pre-hospital system in Singapore from the pre-war days. Every country's prehospital community needs a deep understanding of how they developed over the years, factors that played a part, and the aspirations their community and government have set for this. This can guide future evolution of the services to ensure that care provided is relevant, applicable and in keeping with the community's needs. Countries with similar contextual circumstances, but at a different stage of development of their PECs, may learn from these.

The First In-Human Application of Continuous Low-Irradiance Phototherapy for Chronic Wounds: A Pilot Study.

BACKGROUND: Polymicrobial colonization and resultant biofilm formation significantly impair the process of wound healing. Stagnant tissue repair processes predispose patients to serious complications including systemic infection and limb amputation. Continuous Low-Irradiance Phototherapy (CLIP) is a novel therapeutic approach that delivers blue light at low irradiance for extended periods of time. Bench and preclinical work in the literature indicates that 405 nm light avoids thermal injury of healthy tissue, promotes a cytokine milieu favoring re-epithelialization and angiogenesis, and prevents bacterial and biofilm growth.  Objective: This is the first in-human evaluation of a technology that delivers continuous low-irradiance 405 nm light to chronic wounds. The objective of this study was to determine the safety, feasibility, and ergonomics of this device for the treatment of chronic wounds in adult human subjects. This was not a randomized study to determine device efficacy, although data on outcome were collected. METHODS: In this prospective observational pilot study, participants received the intervention 24 hours per day, 7 days per week, for 4 weeks. Cohort I was conducted from December 2018 to March 2019, with Cohorts II and III ongoing. 25 study participants were recruited by referral (Cohort I: 5 participants, Cohort II: 10 participants, Cohort III: 10 participants). Our primary endpoint was to monitor for safety, assess usability by nurses and physicians, and evaluate patient comfort. The secondary endpoint, although not randomized nor directly compared with standard intervention, was the percentage area reduction (PAR) of the wound.  Results: No adverse events or subject discomfort occurred with the CLIP intervention. The staff treating the study participants reported no ergonomic or compliance issues with the use of the device. The device received high scores in categories assessing practicality and ease of use. There was an average PAR of 29% (SD = 0.42).  Conclusion: This study serves as the first in-human evaluation of extended low-irradiance 405 nm light for chronic wound therapy. The device appears safe and easy to use and had no compliance issues in the outpatient setting. Study participants who received CLIP without interruption saw either partial or complete reduction in wound area.  J Drugs Dermatol. 2023;22(11):1111-1117     doi:10.36849/JDD.7206.

Intravenous Bacille Calmette-Guérin vaccination protects simian immunodeficiency virus-infected macaques from tuberculosis.

Tuberculosis, caused by Mycobacterium tuberculosis (Mtb), is the most common cause of death in people living with human immunodeficiency virus (HIV). Intra-dermal Bacille Calmette-Guérin (BCG) delivery is the only licensed vaccine against tuberculosis; however, it offers little protection from pulmonary tuberculosis in adults and is contraindicated in people living with HIV. Intravenous BCG confers protection against Mtb infection in rhesus macaques; we hypothesized that it might prevent tuberculosis in simian immunodeficiency virus (SIV)-infected macaques, a model for HIV infection. Here intravenous BCG-elicited robust airway T cell influx and elevated plasma and airway antibody titres in both SIV-infected and naive animals. Following Mtb challenge, all 7 vaccinated SIV-naive and 9 out of 12 vaccinated SIV-infected animals were protected, without any culturable bacteria detected from tissues. Peripheral blood mononuclear cell responses post-challenge indicated early clearance of Mtb in vaccinated animals, regardless of SIV infection. These data support that intravenous BCG is immunogenic and efficacious in SIV-infected animals.

The potential of digital behavioural tests as a diagnostic aid for psychosis.

Timely interventions have a proven benefit for people experiencing psychotic illness. One bottleneck to accessing timely interventions is the referral process to the specialist team for early psychosis (STEP). Many general practitioners lack awareness or confidence in recognising psychotic symptoms or state. Additionally, referrals for people without apparent psychotic symptoms, although beneficial at a population level, lead to excessive workload for STEPs. There is a clear unmet need for accurate stratification of STEPs users and healthy cohorts. Here we propose a new approach to addressing this need via the application of digital behavioural tests. To demonstrate that digital behavioural tests can be used to discriminate between the STEPs users (SU; n = 32) and controls (n = 32, age and sex matched), we compared performance of five different classifiers applied to objective, quantitative and interpretable features derived from the 'mirror game' (MG) and trail making task (TMT). The MG is a movement coordination task shown to be a potential socio-motor biomarker of schizophrenia, while TMT is a neuropsychiatric test of cognitive function. All classifiers had AUC in the range of 0.84-0.92. The best of the five classifiers (linear discriminant classifier) achieved an outstanding performance, AUC = 0.92 (95%CI 0.75-1), Sensitivity = 0.75 (95%CI 0.5-1), Specificity = 1 (95%CI 0.75-1), evaluated on 25% hold-out and 1000 folds. Performance of all analysed classifiers is underpinned by the large effect sizes of the differences between the cohorts in terms of the features used for classification what ensures generalisability of the results. We also found that MG and TMT are unsuitable in isolation to successfully differentiate between SU with and without at-risk-mental-state or first episode psychosis with sufficient level of performance. Our findings show that standardised batteries of digital behavioural tests could benefit both clinical and research practice. Including digital behavioural tests into healthcare practice could allow precise phenotyping and stratification of the highly heterogenous population of people referred to STEPs resulting in quicker and more personalised diagnosis. Moreover, the high specificity of digital behavioural tests could facilitate the identification of more homogeneous clinical high-risk populations, benefiting research on prognostic instruments for psychosis. In summary, our study demonstrates that cheap off-the-shelf equipment (laptop computer and a leap motion sensor) can be used to record clinically relevant behavioural data that could be utilised in digital mental health applications.

Stochastic and mixed density functional theory within the projector augmented wave formalism for simulation of warm dense matter.

Stochastic density functional theory (DFT) and mixed stochastic-deterministic DFT are burgeoning approaches for the calculation of the equation of state and transport properties in materials under extreme conditions. In the intermediate warm dense matter regime, a state between correlated condensed matter and kinetic plasma, electrons can range from being highly localized around nuclei to delocalized over the whole simulation cell. The plane-wave basis pseudopotential approach is thus the typical tool of choice for modeling such systems at the DFT level. Unfortunately, stochastic DFT methods scale as the square of the maximum plane-wave energy in this basis. To reduce the effect of this scaling and improve the overall description of the electrons within the pseudopotential approximation, we present stochastic and mixed DFT approaches developed and implemented within the projector augmented wave formalism. We compare results between the different DFT approaches for both single-point and molecular dynamics trajectories and present calculations of self-diffusion coefficients of solid density carbon from 1 to 50 eV.

An Inverse-Designed Nanophotonic Interface for Excitons in Atomically Thin Materials.

Efficient nanophotonic devices are essential for applications in quantum networking, optical information processing, sensing, and nonlinear optics. Extensive research efforts have focused on integrating two-dimensional (2D) materials into photonic structures, but this integration is often limited by size and material quality. Here, we use hexagonal boron nitride (hBN), a benchmark choice for encapsulating atomically thin materials, as a waveguiding layer while simultaneously improving the optical quality of the embedded films. When combined with a photonic inverse design, it becomes a complete nanophotonic platform to interface with optically active 2D materials. Grating couplers and low-loss waveguides provide optical interfacing and routing, tunable cavities provide a large exciton-photon coupling to transition metal dichalcogenide (TMD) monolayers through Purcell enhancement, and metasurfaces enable the efficient detection of TMD dark excitons. This work paves the way for advanced 2D-material nanophotonic structures for classical and quantum nonlinear optics.

NEXMD v2.0 Software Package for Nonadiabatic Excited State Molecular Dynamics Simulations.

We present NEXMD version 2.0, the second release of the NEXMD (Nonadiabatic EXcited-state Molecular Dynamics) software package. Across a variety of new features, NEXMD v2.0 incorporates new implementations of two hybrid quantum-classical dynamics methods, namely, Ehrenfest dynamics (EHR) and the Ab-Initio Multiple Cloning sampling technique for Multiconfigurational Ehrenfest quantum dynamics (MCE-AIMC or simply AIMC), which are alternative options to the previously implemented trajectory surface hopping (TSH) method. To illustrate these methodologies, we outline a direct comparison of these three hybrid quantum-classical dynamics methods as implemented in the same NEXMD framework, discussing their weaknesses and strengths, using the modeled photodynamics of a polyphenylene ethylene dendrimer building block as a representative example. We also describe the expanded normal-mode analysis and constraints for both the ground and excited states, newly implemented in the NEXMD v2.0 framework, which allow for a deeper analysis of the main vibrational motions involved in vibronic dynamics. Overall, NEXMD v2.0 expands the range of applications of NEXMD to a larger variety of multichromophore organic molecules and photophysical processes involving quantum coherences and persistent couplings between electronic excited states and nuclear velocity.

Distributable, Metabolic PET Reporting of Tuberculosis.

Tuberculosis remains a large global disease burden for which treatment regimens are protracted and monitoring of disease activity difficult. Existing detection methods rely almost exclusively on bacterial culture from sputum which limits sampling to organisms on the pulmonary surface. Advances in monitoring tuberculous lesions have utilized the common glucoside [18F]FDG, yet lack specificity to the causative pathogen Mycobacterium tuberculosis (Mtb) and so do not directly correlate with pathogen viability. Here we show that a close mimic that is also positron-emitting of the non-mammalian Mtb disaccharide trehalose - 2-[18F]fluoro-2-deoxytrehalose ([18F]FDT) - can act as a mechanism-based enzyme reporter in vivo. Use of [18F]FDT in the imaging of Mtb in diverse models of disease, including non-human primates, successfully co-opts Mtb-specific processing of trehalose to allow the specific imaging of TB-associated lesions and to monitor the effects of treatment. A pyrogen-free, direct enzyme-catalyzed process for its radiochemical synthesis allows the ready production of [18F]FDT from the most globally-abundant organic 18F-containing molecule, [18F]FDG. The full, pre-clinical validation of both production method and [18F]FDT now creates a new, bacterium-specific, clinical diagnostic candidate. We anticipate that this distributable technology to generate clinical-grade [18F]FDT directly from the widely-available clinical reagent [18F]FDG, without need for either bespoke radioisotope generation or specialist chemical methods and/or facilities, could now usher in global, democratized access to a TB-specific PET tracer.

Airway T cells are a correlate of i.v. Bacille Calmette-Guerin-mediated protection against tuberculosis in rhesus macaques.

Bacille Calmette-Guerin (BCG), the only approved Mycobacterium tuberculosis (Mtb) vaccine, provides limited durable protection when administered intradermally. However, recent work revealed that intravenous (i.v.) BCG administration yielded greater protection in macaques. Here, we perform a dose-ranging study of i.v. BCG vaccination in macaques to generate a range of immune responses and define correlates of protection. Seventeen of 34 macaques had no detectable infection after Mtb challenge. Multivariate analysis incorporating longitudinal cellular and humoral immune parameters uncovered an extensive and highly coordinated immune response from the bronchoalveolar lavage (BAL). A minimal signature predicting protection contained four BAL immune features, of which three remained significant after dose correction: frequency of CD4 T cells producing TNF with interferon γ (IFNγ), frequency of those producing TNF with IL-17, and the number of NK cells. Blood immune features were less predictive of protection. We conclude that CD4 T cell immunity and NK cells in the airway correlate with protection following i.v. BCG.

Optimizing tuberculosis treatment efficacy: Comparing the standard regimen with Moxifloxacin-containing regimens.

Tuberculosis (TB) continues to be one of the deadliest infectious diseases in the world, causing ~1.5 million deaths every year. The World Health Organization initiated an End TB Strategy that aims to reduce TB-related deaths in 2035 by 95%. Recent research goals have focused on discovering more effective and more patient-friendly antibiotic drug regimens to increase patient compliance and decrease emergence of resistant TB. Moxifloxacin is one promising antibiotic that may improve the current standard regimen by shortening treatment time. Clinical trials and in vivo mouse studies suggest that regimens containing moxifloxacin have better bactericidal activity. However, testing every possible combination regimen with moxifloxacin either in vivo or clinically is not feasible due to experimental and clinical limitations. To identify better regimens more systematically, we simulated pharmacokinetics/pharmacodynamics of various regimens (with and without moxifloxacin) to evaluate efficacies, and then compared our predictions to both clinical trials and nonhuman primate studies performed herein. We used GranSim, our well-established hybrid agent-based model that simulates granuloma formation and antibiotic treatment, for this task. In addition, we established a multiple-objective optimization pipeline using GranSim to discover optimized regimens based on treatment objectives of interest, i.e., minimizing total drug dosage and lowering time needed to sterilize granulomas. Our approach can efficiently test many regimens and successfully identify optimal regimens to inform pre-clinical studies or clinical trials and ultimately accelerate the TB regimen discovery process.

Does witness type affect the chance of receiving bystander CPR in out-of-hospital cardiac arrest?

OBJECTIVES: The relationship between the bystander witness type and receipt of bystander CPR (BCPR) is not well understood. Herein we compared BCPR administration between family and non-family witnessed out-of-hospital cardiac arrest (OHCA). BACKGROUND: In many communities, interventions in the past decade have contributed to an increased receipt of BCPR, for example in Singapore from 15% to 60%. However, BCPR rates have plateaued despite sustained and ongoing community-based interventions, which may be related to gaps in education or training for various witness types. The purpose of this study was to investigate the association between witness type and BCPR administration. METHODS: Singapore data from 2010-2020 was extracted from the Pan-Asian Resuscitation Outcomes Study (PAROS) network registry (n = 25,024). All adult, layperson witnessed, non-traumatic OHCAs were included in this study. RESULTS: Of 10,016 eligible OHCA cases, 6,895 were family witnessed and 3,121 were non-family witnessed. After adjustment for potential confounders, BCPR administration was less likely for non-family witnessed OHCA (OR 0.83, 95% CI 0.75, 0.93). After location stratification, non-family witnessed OHCAs were less likely to receive BCPR in residential settings (OR 0.75, 95% CI 0.66, 0.85). In non-residential settings, there was no statistically significant association between witness type and BCPR administration (OR 1.11, 95% CI 0.88, 1.39). Details regarding witness type and bystander CPR were limited. CONCLUSION: This study found differences in BCPR administration between family and non-family witnessed OHCA cases. Elucidation of witness characteristics may be useful to determine populations that would benefit most from CPR education and training.