Bridging length scales in organic mixed ionic-electronic conductors through internal strain and mesoscale dynamics

Understanding the structural and dynamic properties of disordered systems at the mesoscale is crucial. This is particularly important in organic mixed ionic-electronic conductors (OMIECs), which undergo significant and complex structural changes when operated in an electrolyte. In this study, we investigate the mesoscale strain, reversibility and dynamics of a model OMIEC material under external electrochemical potential using operando X-ray photon correlation spectroscopy. Our results reveal that strain and structural hysteresis depend on the sample's cycling history, establishing a comprehensive kinetic sequence bridging the macroscopic and microscopic behaviours of OMIECs. Furthermore, we uncover the equilibrium and non-equilibrium dynamics of charge carriers and material-doping states, highlighting the unexpected coupling between charge carrier dynamics and mesoscale order. These findings advance our understanding of the structure-dynamics-function relationships in OMIECs, opening pathways for designing and engineering materials with improved performance and functionality in non-equilibrium states during device operation.

Particle Dynamics in a Diblock-Copolymer-Based Dodecagonal Quasicrystal and Its Periodic Approximant by X-Ray Photon Correlation Spectroscopy

Temperature-dependent x-ray photon correlation spectroscopy (XPCS) measurements are reported for a binary diblock-copolymer blend that self-assembles into an aperiodic dodecagonal quasicrystal and a periodic Frank-Kasper σ phase approximant. The measured structural relaxation times are Bragg scattering wavevector independent and are 5 times faster in the dodecagonal quasicrystal than the σ phase, with minimal temperature dependence. The underlying dynamical relaxations are ascribed to differences in particle motion at the grain boundaries within each of these tetrahedrally close-packed assemblies. These results identify unprecedented particle dynamics measurements of tetrahedrally coordinated micellar block polymers, thus expanding the application of XPCS to ordered soft materials.

Deconstructing Differential Drug Coverage within a Malaysian Media Source

Many researchers have noted that media coverage of drugs can be sensationalized and/or have questionable accuracy. Additionally, it has been alleged that the media often treats all drugs as harmful and can fail to differentiate between different types of drugs. Within this context, the researchers sought to deconstruct how media coverage was similar and/or different according to drug type within a national media outlet in Malaysia. Our sample comprised 487 news articles published over a two-year period. Articles were coded to reflect thematic differences in drug framing. We focus on five drugs widely used in Malaysia (amphetamines, opiates, cannabis, cocaine, and kratom) and assess the most frequent themes, crimes, and locations mentioned in reference to each drug. All drugs were primarily covered in a criminal justice context, and articles highlighted concern about the spread of these drugs and their abuse. Drug coverage varied, particularly in association with violent crimes, specific regions, and discussion of legality. We find evidence of both similarities and differences in how drugs were covered. Variation in coverage demonstrated that certain drugs were deemed a heightened threat, as well as reflected broader social/political processes shaping ongoing debates over treatment approaches and legality.

Kratom (Mitragyna speciosa) use in a sample of drug-dependent adolescents in rehabilitation for drug use in Malaysia

BACKGROUND

Leaves derived from the Kratom (Mitragyna speciosa) tree have been traditionally ingested for their curative properties by diverse groups of the population including people who use drugs (PWUDs) in Southeast Asia. This study investigated the motives for using kratom among drug-dependent adolescents.

METHODS

Eighty adolescents who were undergoing mandatory drug rehabilitation volunteered to participate in this mixed-method, cross-sectional study. All respondents answered a semi-structured questionnaire while a few were interviewed in-depth.

RESULTS

The majority were males (70%, n = 56/80). The respondents' mean age at admission was 18.2 years (SD = 1.40), and 65% were between 14 and 18 years old. Sixty-three percent (n = 50/80) had used crystal methamphetamine alone, while the rest had co-used crystal methamphetamine with heroin. About three-fifths (60%, n = 48/80) had a history of kratom use. Kratom was commonly used for many perceived benefits such as increasing energy, reducing crystal methamphetamine intake, intensifying euphoria, easing heroin withdrawal, as a heroin substitute and reducing heroin use. In addition, the multivariate analysis indicated that higher odds of kratom use were associated with those who were employed, used only crystal methamphetamine, were recent drug users, and had no prior incarceration history.

CONCLUSION

While kratom was being used for its multifold perceived benefits, it also functions as a means to self-treat withdrawal from illicit drug use among drug-dependent adolescents.

Student Experiential Activities: A Novel Strategy to Teach Neuroanatomy in Lectures

Introduction Activity-based teaching is a widely used pedagogical tool for enhancing anatomy learning. However, involving the learner in experiential activities in lectures is an unexplored area in medical research. The present study aims to determine whether incorporating student experiential activities into lectures impacts student's learning of neuroanatomy. Materials and methods We used a pre-test/post-test experimental study design to compare the learning outcome between the experiential activity based lecture and traditional lectures. We divided 150 students into control (75 students) and intervention groups (75 students). To assess the baseline knowledge on the subject, the students attended 20 clinical scenario-based multiple-choice questions two weeks before the lectures. Then, both groups attended two lecture sessions on the functional areas of the brain. In the control group, the students drew the boundaries of a particular cerebral area and labeled its function and clinical symptoms. In the intervention group, the learners participated in experiential activities while following the instructions. The lecturer used their response as a scaffold to explain the function and clinical correlation of a specific part of the cerebral cortex. The same test questions were given to the students one week after the final lecture session to evaluate their level of understanding. We analyzed the scores of 111 students (57 students in the control group and 54 students in the interventional group) who attended the two lectures and pre- and post-test sessions. Students also completed a validated 10-item feedback questionnaire regarding their perception of the teaching sessions. Results The mean score improvement for the control and intervention groups was 4.86 ± 1.53 and 6.39 ± 2.93, respectively. The score improvement of the activity group was significantly higher than that of the control group (p = 0.006; d = 0.65). The perception scores of interest, knowledge attainment, and satisfaction were significantly higher in the intervention group compared to the control group. Conclusion The findings of this study suggest that experiential activities facilitate better comprehension of abstract neuroanatomical concepts as compared to traditional didactic teaching.

Correlation between the particle size, structural and photoluminescence spectra of nano NiCr2O4 and La doped NiCr2O4 materials

Nano NiCr2O4 undoped and La doped NiCr2O4 nanorods array were successfully prepared by solution based conventional method[sbcm]. The synthesized samples were characterized by the diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) spectroscopy for finding optical properties. Further, the samples structure confirmed by Fourier transforms infrared (FTIR), and X-ray diffraction (XRD)techniques. High-resolution transmission electron microscopy (HRTEM) analysis revealed the attachment of NiCr2O4 nanorods on surface of nanoparticles. From the results, it was found that the reaction time, band gap energy, and particle size strongly influenced by changing the concentration of La in NiCr2O4. This work is notable for its examination of the impact of the precursor on the optical and structural characteristics of samples of La-doped and undoped NiCr2O4. This was the first time the investigation had been done. The average particle size of the La-doped and undoped NiCr2O4 samples is between 16 and 24 nm.

Artificial Intelligence Revolutionizing the Field of Medical Education

Medical education has ventured into a new arena of computer-assisted teaching powered by artificial intelligence (AI). In medical institutions, AI can serve as an intelligent tool facilitating the decision-making process effectively. AI can enhance teaching by assisting in developing new strategies for educators. Similarly, students also benefit from intelligent systems playing the role of competent teachers. Thus, AI-integrated medical education paves new opportunities for advanced teaching and learning experiences and improved outcomes. On the other hand, optical mark recognition and automated scoring are ways AI can also transform into a real-time assessor and evaluator in medical education. This review summarizes the AI tools and their application in medical teaching or learning, assessment, and administrative support. This article can aid medical institutes in planning and implementing AI according to the needs of the educators.

Multivariable model of postoperative delirium in cardiac surgery patients: proteomic and demographic contributions

Background

Delirium following cardiac surgery is common, morbid, and costly, but may be prevented with risk stratification and targeted intervention. Preoperative protein signatures may identify patients at increased risk for worse postoperative outcomes, including delirium. In this study, we aimed to identify plasma protein biomarkers and develop a predictive model for postoperative delirium in older patients undergoing cardiac surgery, while also uncovering possible pathophysiological mechanisms.

Methods

SOMAscan analysis of 1,305 proteins in the plasma from 57 older adults undergoing cardiac surgery requiring cardiopulmonary bypass was conducted to define delirium-specific protein signatures at baseline (PREOP) and postoperative day 2 (POD2). Selected proteins were validated in 115 patients using the ELLA multiplex immunoassay platform. Proteins were combined with clinical and demographic variables to build multivariable models that estimate the risk of postoperative delirium and bring light to the underlying pathophysiology.

Results

A total of 115 and 85 proteins from SOMAscan analyses were found altered in delirious patients at PREOP and POD2, respectively (p<0.05). Using four criteria including associations with surgery, delirium, and biological plausibility, 12 biomarker candidates (Tukey's fold change (|tFC|)>1.4, Benjamini-Hochberg (BH)-p<0.01) were selected for ELLA multiplex validation. Eight proteins were significantly altered at PREOP, and seven proteins at POD2 (p<0.05), in patients who developed postoperative delirium compared to non-delirious patients. Statistical analyses of model fit resulted in the selection of a combination of age, sex, and three proteins (angiopoietin-2 (ANGPT2); C-C motif chemokine 5 (CCL5); and metalloproteinase inhibitor 1 (TIMP1); AUC=0.829) as the best performing predictive model for delirium at PREOP. The delirium-associated proteins identified as biomarker candidates are involved with inflammation, glial dysfunction, vascularization, and hemostasis, highlighting the multifactorial pathophysiology of delirium.

Conclusion

Our study proposes a model of postoperative delirium that includes a combination of older age, female sex, and altered levels of three proteins. Our results support the identification of patients at higher risk of developing postoperative delirium after cardiac surgery and provide insights on the underlying pathophysiology. ClinicalTrials.gov ( NCT02546765 ).

Intra-Operative Radiotherapy (IORT) in Breast Conserving Therapy in Early-Stage Breast Cancer and DCIS

PURPOSE/OBJECTIVE(S)

Initial breast intra-operative radiotherapy (IORT) results in clinical trials were encouraging though with longer follow up, increased local recurrences have been reported compared with whole breast radiation or other partial breast radiation including accelerated partial breast irradiation (APBI) methods. The goal of the study is to report our prospective single institution IORT breast study outcomes of local recurrence (LR) including true recurrence and breast elsewhere failures, breast cancer specific survival (BCSS), and overall survival (OS) with low energy x-ray IORT in early-stage breast cancer or ductal carcinoma in situ.

MATERIALS/METHODS

A total of 480 patients with early-stage breast cancer or DCIS were prospectively enrolled in an IRB approved single institution trial and treated with low energy X-ray IORT 20 Gy at time of breast-conserving surgery. Eligibility criteria included ≥ 45 years of age with unifocal tumors < 3 cm deemed candidates for partial mastectomy. Supplemental external beam radiation was recommended for patients with high-risk surgical pathology including multifocal disease, positive nodes, close margins < 2 mm, or lymphovascular invasion. Ipsilateral breast tumor recurrences were classified as true recurrence versus elsewhere failure by location and histology: same/different quadrant and similar/different histology. Kaplan-Meier methods were used to estimate survival probabilities across time.

RESULTS

Median age of enrolled patients was 64 years with the majority of patients having favorable phenotype with 94% ER+ and 93% Her-2 - disease. 110 patients (23%) had supplemental EBRT delivered; 103 to the whole breast and 7 to the breast and regional nodes. At a median follow up of 73 months (range 17 - 131 months), there were 23 (4.8%) ipsilateral breast tumor recurrences, of which 9 were true recurrences (1.9%) and 14 elsewhere failures (2.9%). One patient with true recurrence and 3 patients with elsewhere breast failures synchronously presented with clinical or radiographic regional node involvement. Seven patient developed contralateral breast cancer and 8 patients developed distant metastases during the follow-up period. There were 2 breast cancer related deaths. At 6-years, overall survival rate was 96.8% and breast cancer specific survival was 98.7%.

CONCLUSION

Our study outcomes reflect similar outcomes as other reported IORT studies with electron or low energy X-ray in breast cancer, with higher risk of local failure than historical whole breast and other partial breast radiation techniques. This supports current radiation society guidelines for IORT monotherapy for breast cancer to be optimally considered in the context of prospective clinical trials.

Data Driven Approach to Exactrac Setup Parameters after CBCT for Cranial Radiotherapy

PURPOSE/OBJECTIVE(S)

The purpose of this study is to 1) Determine the congruence of shifts derived from Cone-Beam CT (CBCT) and from Exactrac dynamic KV X-rays 2) To setup action levels for Exactrac imaging to determine if patient potentially moved between CBCT and Exactrac acquisition and 3) To analyze if Exactrac alone can be reliably used for cranial setup forgoing the CBCT step MATERIALS/METHODS: Exactrac dynamic, uses in-room KV X-ray imaging that is mounted on the floor to monitor patient positioning during treatment. The congruence of imaging and radiation isocenter for the LINAC and Exactrac system was verified using the Winston-Lutz (WL) test over a period of one year. The WL pointer was set up and its coincidence with imaging and radiation isocenter was confirmed. Exactrac images were then acquired at various couch angles and the pointer deviation from Exactrac imaging isocenter is noted. Secondly, translation and rotation shifts for 175 consecutive cranial cases were examined to determine the deviation between shifts as denoted by CBCT and Exactrac. These patients were initially set up using CBCT and then once in treatment position, Exactrac KV images were acquired to check for any deviation. The deviation between the two systems was collected and a Kolomogorov-Smirnov (KS) test was performed on the data to check for the normality of the distribution. Statistical Process Control (SPC) was performed to derive action levels for Exactrac based shifts after CBCT.

RESULTS

Based on repeated Winston-Lutz tests over a period of one year, the maximum deviation between radiation and imaging isocenters and Exactrac isocenter was 0.3mm and 0.3 deg over all couch angles. This number remained stable over the entire time period without necessitating any recalibration of Exactrac isocenter. Based on patient data for cranial cases, the mean and standard deviations for the largest shifts were (0.45 mm, 0.40 mm) for translations (range 0 - 2.03mm) and (0.44 deg and 0.32 deg) for rotations (range 0 - 2.21 degree). Using SPC, it was decided that the action level for translations and rotations could be set to 0.8mm and 0.5 deg respectively. Any deviation beyond this action level necessitates re-imaging to verify that the patient did not move in between the CBCT and Exactrac imaging acquisitions CONCLUSION: Exactrac system derived shifts show excellent agreement with CBCT. The isocentricity of the systems is maintained over a long period of time and shows no drift. Either system can be reliably used to set up cranial patients. With the added advantage of speed of acquisition, matching and shifts, the Exactrac system could replace CBCT for daily setup of patients undergoing cranial radiotherapy.

Kinetics of Shear-Induced Structural Ordering in Dense Colloids

The macroscopic rheological response of a colloidal solution is highly correlated with the local microscopic structure, as revealed by an in situ Rheo-SAXS experiment with a high temporal resolution. Oscillatory shear can induce a strain-controlled ordering-to-disorder transition, resulting in a shear-thickening process that is different from the normal shear-thickening behavior that is driven by hydrodynamics and particle friction. We reveal that there is a complex time-dependent kinetics toward structural ordering under different applied strains. When the strain amplitude reaches a critical value that starts to induce disordering in the system, the pathway toward the dynamic equilibrium can also become highly non-monotonic. Within the same oscillatory cycle, there is a strong correlation of ordering with different phases of the oscillation, with the system oscillating between two dynamic metastable states.

Azimuthal Correlations within Exclusive Dijets with Large Momentum Transfer in Photon-Lead Collisions

The structure of nucleons is multidimensional and depends on the transverse momenta, spatial geometry, and polarization of the constituent partons. Such a structure can be studied using high-energy photons produced in ultraperipheral heavy-ion collisions. The first measurement of the azimuthal angular correlations of exclusively produced events with two jets in photon-lead interactions at large momentum transfer is presented, a process that is considered to be sensitive to the underlying nuclear gluon polarization. This study uses a data sample of ultraperipheral lead-lead collisions at sqrt[s_{NN}]=5.02  TeV, corresponding to an integrated luminosity of 0.38  nb^{-1}, collected with the CMS experiment at the LHC. The measured second harmonic of the correlation between the sum and difference of the two jet transverse momentum vectors is found to be positive, and rising, as the dijet transverse momentum increases. A well-tuned model that has been successful at describing a wide range of proton scattering data from the HERA experiments fails to describe the observed correlations, suggesting the presence of gluon polarization effects.

Microscopic Origins of the Nonlinear Behavior of Particle-Filled Rubber Probed with Dynamic Strain XPCS

The underlying microscopic response of filler networks in reinforced rubber to dynamic strain is not well understood due to the experimental difficulty of directly measuring filler network behavior in samples undergoing dynamic strain. This difficulty can be overcome with in situ X-ray photon correlation spectroscopy (XPCS) measurements. The contrast between the silica filler and the rubber matrix for X-ray scattering allows us to isolate the filler network behavior from the overall response of the rubber. This in situ XPCS technique probes the microscopic breakdown and reforming of the filler network structure, which are responsible for the nonlinear dependence of modulus on strain, known in the rubber science community as the Payne effect. These microscopic changes in the filler network structure have consequences for the macroscopic material performance, especially for the fuel efficiency of tire tread compounds. Here, we elucidate the behavior with in situ dynamic strain XPCS experiments on industrially relevant, vulcanized rubbers filled (13 vol %) with novel air-milled silica of ultrahigh-surface area (UHSA) (250 m²/g). The addition of a silane coupling agent to rubber containing this silica causes an unexpected and counterintuitive increase in the Payne effect and decrease in energy dissipation. For this rubber, we observe a nearly two-fold enhancement of the storage modulus and virtually equivalent loss tangent compared to a rubber containing a coupling agent and conventional silica. Interpretation of our in situ XPCS results simultaneously with interpretation of traditional dynamic mechanical analysis (DMA) strain sweep experiments reveals that the debonding or yielding of bridged bound rubber layers is key to understanding the behavior of rubber formulations containing the silane coupling agent and high-surface area silica. These results demonstrate that the combination of XPCS and DMA is a powerful method for unraveling the microscale filler response to strain which dictates the dynamic mechanical properties of reinforced soft matter composites. With this combination of techniques, we have elucidated the great promise of UHSA silica when used in concert with a silane coupling agent in filled rubber. Such composites simultaneously exhibit large moduli and low hysteresis under dynamic strain.

Investigation of the yielding transition in concentrated colloidal systems via rheo-XPCS

We probe the microstructural yielding dynamics of a concentrated colloidal system by performing creep/recovery tests with simultaneous collection of coherent scattering data via X-ray Photon Correlation Spectroscopy (XPCS). This combination of rheology and scattering allows for time-resolved observations of the microstructural dynamics as yielding occurs, which can be linked back to the applied rheological deformation to form structure-property relations. Under sufficiently small applied creep stresses, examination of the correlation in the flow direction reveals that the scattering response recorrelates with its predeformed state, indicating nearly complete microstructural recovery, and the dynamics of the system under these conditions slows considerably. Conversely, larger creep stresses increase the speed of the dynamics under both applied creep and recovery. The data show a strong connection between the microstructural dynamics and the acquisition of unrecoverable strain. By comparing this relationship to that predicted from homogeneous, affine shearing, we find that the yielding transition in concentrated colloidal systems is highly heterogeneous on the microstructural level.

The effect of dynamically heterogeneous interphases on the particle dynamics of polymer nanocomposites

The entanglements of dynamically asymmetric polymer layers influence relaxations of nanoparticles in polymer nanocomposites. In this work, the dynamics of polymer-adsorbed and polymer-grafted nanoparticles in a poly(methyl acrylate) matrix polymer was investigated using X-ray photon correlation spectroscopy (XPCS) to understand the role of chain rigidity and chemical heterogeneities in particle dynamics. Locations of dynamic heterogeneities close to nanoparticles and away from particle surfaces were examined with the comparison of adsorbed and grafted nanoparticles. Our results show that the chemical heterogeneities around dispersed nanoparticles transitioned the particle dynamics from Brownian diffusion into hyperdiffusion, and moreover, the high rigidity of chains in the chemically heterogeneous interfacial layers slowed down the particle dynamics. The hyperdiffusion measured both in grafted particles and adsorbed particles was attributed to the dense interfacial mixing of dynamically heterogeneous chains.

Multislice forward modeling of coherent surface scattering imaging on surface and interfacial structures

To study nanostructures on substrates, surface-sensitive reflection-geometry scattering techniques such as grazing incident small angle X-ray scattering are commonly used to yield an averaged statistical structural information of the surface sample. Grazing incidence geometry can probe the absolute three-dimensional structural morphology of the sample if a highly coherent beam is used. Coherent surface scattering imaging (CSSI) is a powerful yet non-invasive technique similar to coherent X-ray diffractive imaging (CDI) but performed at small angles and grazing-incidence reflection geometry. A challenge with CSSI is that conventional CDI reconstruction techniques cannot be directly applied to CSSI because the Fourier-transform-based forward models cannot reproduce the dynamical scattering phenomenon near the critical angle of total external reflection of the substrate-supported samples. To overcome this challenge, we have developed a multislice forward model which can successfully simulate the dynamical or multi-beam scattering generated from surface structures and the underlying substrate. The forward model is also demonstrated to be able to reconstruct an elongated 3D pattern from a single shot scattering image in the CSSI geometry through fast-performing CUDA-assisted PyTorch optimization with automatic differentiation.

Gelation and Re-entrance in Mixtures of Soft Colloids and Linear Polymers of Equal Size

Liquid mixtures composed of colloidal particles and much smaller non-adsorbing linear homopolymers can undergo a gelation transition due to polymer-mediated depletion forces. We now show that the addition of linear polymers to suspensions of soft colloids having the same hydrodynamic size yields a liquid-to-gel-to-re-entrant liquid transition. In particular, the dynamic state diagram of 1,4-polybutadiene star-linear polymer mixtures was determined with the help of linear viscoelastic and small-angle X-ray scattering experiments. While keeping the star polymers below their nominal overlap concentration, a gel was formed upon increasing the linear polymer content. Further addition of linear chains yielded a re-entrant liquid. This unexpected behavior was rationalized by the interplay of three possible phenomena: (i) depletion interactions, driven by the size disparity between the stars and the polymer length scale which is the mesh size of its entanglement network; (ii) colloidal deswelling due to the increased osmotic pressure exerted onto the stars; and (iii) a concomitant progressive suppression of the depletion efficiency on increasing the polymer concentration due to reduced mesh size, hence a smaller range of attraction. Our results unveil an exciting new way to tailor the flow of soft colloids and highlight a largely unexplored path to engineer soft colloidal mixtures.

Rheology and dynamics of a solvent segregation driven gel (SeedGel)

Bicontinuous structures promise applications in a broad range of research fields, such as energy storage, membrane science, and biomaterials. Kinetically arrested spinodal decomposition is found responsible for stabilizing such structures in different types of materials. A recently developed solvent segregation driven gel (SeedGel) is demonstrated to realize bicontinuous channels thermoreversibly with tunable domain sizes by trapping nanoparticles in a particle domain. As the mechanical properties of SeedGel are very important for its future applications, a model system is characterized by temperature-dependent rheology. The storage modulus shows excellent thermo-reproducibility and interesting temperature dependence with the maximum storage modulus observed at an intermediate temperature range (around 28 °C). SANS measurements are conducted at different temperatures to identify the macroscopic solvent phase separation during the gelation transition, and solvent exchange between solvent and particle domains that is responsible for this behavior. The long-time dynamics of the gel is further studied by X-ray Photon Correlation Spectroscopy (XPCS). The results indicate that particles in the particle domain are in a glassy state and their long-time dynamics are strongly correlated with the temperature dependence of the storage modulus.

Resolving Salt-Induced Agglomeration of Laponite Suspensions Using X-ray Photon Correlation Spectroscopy and Molecular Dynamics Simulations

Linking the physics of the relaxation behavior of viscoelastic fluids as they form arrested gel states to the underlying chemical changes is essential for developing predictive controls on the properties of the suspensions. In this study, 3 wt.% laponite suspensions are studied as model systems to probe the influence of salt-induced relaxation behavior arising from the assembly of laponite nanodisks. X-ray Photon Correlation Spectroscopy (XPCS) measurements show that laponite suspensions prepared in the presence of 5 mM concentrations of CaCl₂, MgCl₂ and CsCl salts accelerate the formation of arrested gel states, with CaCl₂ having a significant impact followed by CsCl and MgCl₂ salts. The competing effects of ion size and charge on relaxation behavior are noted. For example, the relaxation times of laponite suspensions in the presence of Mg²⁺ ions are slower compared to Cs+ ions despite the higher charge, suggesting that cation size dominates in this scenario. The faster relaxation behavior of laponite suspensions in the presence of Ca²⁺ ions compared to Cs⁺ ions shows that a higher charge dominates the size of the ion. The trends in relaxation behavior are consistent with the cluster formation behavior of laponite suspensions and the electrostatic interactions predicted from MD simulations. Charge balance is achieved by the intercalation of the cations at the negatively charged surfaces of laponite suspensions. These studies show that the arrested gel state of laponite suspensions is accelerated in the presence of salts, with ion sizes and charges having a competing effect on relaxation behavior.

Measurements of the associated production of a W boson and a charm quark in proton-proton collisions at s = 8 TeV

Measurements of the associated production of a W boson and a charm ( c ) quark in proton-proton collisions at a centre-of-mass energy of 8 TeV are reported. The analysis uses a data sample corresponding to a total integrated luminosity of 19.7 fb - 1 collected by the CMS detector at the LHC. The W bosons are identified through their leptonic decays to an electron or a muon, and a neutrino. Charm quark jets are selected using distinctive signatures of charm hadron decays. The product of the cross section and branching fraction σ ( pp → W + c + X ) B ( W → ℓ ν ) , where ℓ = e or μ , and the cross section ratio σ ( pp → W + + c ¯ + X ) / σ ( pp → W - + c + X ) are measured in a fiducial volume and differentially as functions of the pseudorapidity and of the transverse momentum of the lepton from the W boson decay. The results are compared with theoretical predictions. The impact of these measurements on the determination of the strange quark distribution is assessed.

Barriers to enrolling in voluntary treatment programs in Malaysia: a study of women who use methamphetamine (WWUM)

Women with substance use disorders (SUDs) have been widely reported to face barriers in seeking treatment. We sought to identify barriers that prevented women who use methamphetamine (WWUM) from accessing the decade-old Voluntary Treatment Centers (VTCs) in Malaysia. A total of 153 WWUM who were undergoing rehabilitation for methamphetamine use at a compulsory drug detention center (CDDC) were recruited for this cross-sectional study. Data were collected by canvasing a structured questionnaire through face-to-face meetings. Of the total sample, 131 (86%) were Malays, with a mean age of 32.1 years. The commonly cited treatment barriers were the belief that methamphetamine use was not problematic (42%), not knowing how to seek treatment (38%), feeling embarrassed to seek treatment (33%), the lack of family support (24%), and the long waiting time for enrollment (23%). Logistic analyses indicated that a longer duration of use increased the odds of not acknowledging methamphetamine use as a problem while older participants had lower odds of holding a similar view. A longer duration of use also increased the odds of claiming treatment was not needed but lowered the odds of asserting a lack of confidence in treatment. Furthermore, Malays had higher odds of lacking family support in seeking treatment while being employed lowered the odds of not wanting treatment. Addressing these concerns will hopefully encourage higher participation of WWUM in voluntary treatment programs.

Linking scientific instruments and computation: Patterns, technologies, and experiences

Powerful detectors at modern experimental facilities routinely collect data at multiple GB/s. Online analysis methods are needed to enable the collection of only interesting subsets of such massive data streams, such as by explicitly discarding some data elements or by directing instruments to relevant areas of experimental space. Thus, methods are required for configuring and running distributed computing pipelines—what we call flows—that link instruments, computers (e.g., for analysis, simulation, artificial intelligence [AI] model training), edge computing (e.g., for analysis), data stores, metadata catalogs, and high-speed networks. We review common patterns associated with such flows and describe methods for instantiating these patterns. We present experiences with the application of these methods to the processing of data from five different scientific instruments, each of which engages powerful computers for data inversion,model training, or other purposes. We also discuss implications of such methods for operators and users of scientific facilities.

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Patterns for linking instruments and computers for online analysis are reviewed

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Methods are presented for capturing such “flows” in reusable forms

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The use of Globus automation services to run flows is described

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Implications of these methods for scientists and facilities are discussed

The industrial revolution transformed society via large-scale automation of manufacturing. Today, AI- and robotics-driven automation of scientific research seems set to usher in a new era of accelerated discovery. But just as the industrial revolution depended on new replicable and scalable manufacturing processes and methods for delivering the copious mechanical power required by those processes, so the automated discovery revolution demands new methods for implementing research automation processes and for connecting those processes to computing and data power. We present here new methods that address these essential needs by allowing scientists to capture common automation patterns in reusable flows and to embed such flows in a global trust, data, and computing fabric that enables instant access to powerful AI, simulation, and other computational capabilities. We use examples from synchrotron light sources to show how these methods can be realized in software and applied at scale.

pyXPCSviewer: an open-source interactive tool for X-ray photon correlation spectroscopy visualization and analysis

pyXPCSviewer, a Python-based graphical user interface that is deployed at beamline 8-ID-I of the Advanced Photon Source for interactive visualization of XPCS results, is introduced. pyXPCSviewer parses rich X-ray photon correlation spectroscopy (XPCS) results into independent PyQt widgets that are both interactive and easy to maintain. pyXPCSviewer is open-source and is open to customization by the XPCS community for ingestion of diversified data structures and inclusion of novel XPCS techniques, both of which are growing demands particularly with the dawn of near-diffraction-limited synchrotron sources and their dedicated XPCS beamlines.

First Search for Exclusive Diphoton Production at High Mass with Tagged Protons in Proton-Proton Collisions at sqrt[s]=13 TeV

A search for exclusive two-photon production via photon exchange in proton-proton collisions, pp→pγγp with intact protons, is presented. The data correspond to an integrated luminosity of 9.4  fb^{-1} collected in 2016 using the CMS and TOTEM detectors at a center-of-mass energy of 13 TeV at the LHC. Events are selected with a diphoton invariant mass above 350 GeV and with both protons intact in the final state, to reduce backgrounds from strong interactions. The events of interest are those where the invariant mass and rapidity calculated from the momentum losses of the forward-moving protons match the mass and rapidity of the central, two-photon system. No events are found that satisfy this condition. Interpreting this result in an effective dimension-8 extension of the standard model, the first limits are set on the two anomalous four-photon coupling parameters. If the other parameter is constrained to its standard model value, the limits at 95% confidence level are |ζ_{1}|<2.9×10^{-13}  GeV^{-4} and |ζ_{2}|<6.0×10^{-13}  GeV^{-4}.

Relaxation and Aging of Nanosphere Assemblies at a Water-Oil Interface

The relaxation and aging of an assembly of spherical nanoparticles (NPs) at a water-oil interface are characterized in situ by grazing incidence X-ray photon correlation spectroscopy. The dynamics of the interfacial assembly is measured while the interface saturates with NPs. Weak attractions between NPs lead to gel-like structures in the assembly, where the in-plane ordering is inhibited by the broad size distribution of the NPs. Structural rearrangements on the length scale of the NP-NP center-to-center distances proceed by intermittent fluctuations instead of continuous cooperative motions. The coexistence of rapid and slow NP populations is confirmed, as commonly observed in soft glass-forming materials. Dynamics are increasingly slowed as the NPs initially segregate to the locally clustered interface. The structural relaxation of the NPs in these localized clusters is 5 orders of magnitude slower than that of free particles in the bulk. When the interface is nearly saturated, the time for relaxation increases suddenly due to the onset of local jamming, and the dynamics slow exponentially afterward until the system reaches collective jamming by cooperative rearrangements. This investigation provides insights into structural relaxations near the glass transition and the evolution of the structure and dynamics of the assemblies as they transition from an isotropic liquid to a dense disordered film.

POS0763 A MULTIMODAL MAGNETIC RESONANCE IMAGING STUDY OF COGNITIVE FUNCTION IN SYSTEMIC LUPUS ERYTHEMATOSUS: A MACHINE LEARNING APPROACH

Background

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disorder that can affect the central nervous system. Cognitive dysfuncion is the most common neuropsyhiatric event in SLE patients, yet it is also one of the hardest to diagnose.

Objectives

To investigate if multimodal imaging to assess anatomical magnetic resonance imaging (MRI) abnormalities in the brains of SLE patients can predict cognitive function.

Methods

Subjects underwent voxel-based morphometry (VBM), magnetization transfer imaging (MTI), and dynamic contrast-enhanced (DCE) MRI. Automated Neuropsychological Assessment Metrics (ANAM) was used to assess cognitive function in this cross-sectional study and the primary measure was the total throughput score (TTS). TTS is the total of the throughput scores for each of the 8 ANAM subtests: (i) code substitution learning (CSL); (ii) code substitution immediate (CSI); (iii) code substitution delayed (CSD); (iv) spatial processing (SP); (v) matching to sample (MSP); (vi) running memory continuous performance test (CPT); (vii) mathematical processing (MTH) and (viii) memory search (MS). Olfactory assessment was done using the University of Pennsylvania Smell Identification Test. We used a machine learning-based model (i.e. GLMnet) to predict TTS. Subjects with active SLE disease or above 40 years old were excluded.

Results

Thirty SLE patients [26 female, 32.0 (26.8-37.0) years] without clinically overt neuropsychiatric manifestations and 10 healthy controls (HCs) [9 females, 27.0 (23.0-31.5) years] were enrolled in this study. Both groups had comparable cognitive and olfactory functions. No significant differences were observed in VBM, MTR, olfactory blub and tract (OBT) volume in SLE patients compared to HCs. We observed increased blood-brain barrier (BBB) permeability parameters (Ktrans and PS) in several regions of SLE patients. DCE-MRI perfusion parameters such as perfusion (F) and vp but not permeability measures were associated with TTS. In particular, F right amygdala correlated with TTS in SLE patients (r = 0.636, FDR p < 0.05) (Table 1). Using GLMnet, we trained a multimodal MRI model comprising of VBM, MTR, DCE-MRI and OBT volume parameters to predict TTS in SLE patients (r = 0.998, p < 0.0005) (Figure 1).

Figure 1.

Machine learning-based models to predict cognitive function.

Table 1.

Correlation between ANAM tests with perfusion (F) in SLE patients, ranked in descending order of statistical significance for TTS.

VariableTTSCSLCSICSDSPMSPCPTMTHMSF right amygdala0.636‡*0.520‡0.3370.437†0.559‡0.3230.633‡0.412†0.598‡F left entorhinal0.504‡0.422†0.3660.416†0.3050.1850.530‡0.1860.416†F left amygdale0.495‡0.400†0.1890.378†0.3300.2370.491‡0.376†0.449†F choroid0.469†0.384†0.2160.413†0.458†0.2020.456†0.3400.406†plexusF right rostal anterior cingulate0.453†0.3010.1180.2960.393†0.2140.547‡0.420†0.383†F right entorhinal0.448†0.368†0.2320.3120.376†0.1560.438†0.2710.407†F cerebellum white matter0.427†0.3580.2010.370†0.2730.0780.449†0.2900.297F left hippocampus0.427†0.3550.1340.390†0.3560.2030.511‡0.3360.332F brain stem0.407†0.2980.1380.2750.2940.1530.478‡0.3080.369†F right insula0.407†0.3080.0740.3000.3240.1760.437†0.3230.347F left parietal0.400†0.2630.0920.2540.2940.2240.487‡0.2740.332F ventricles0.396†0.3030.0830.3210.370†0.1920.477‡0.2860.361F right temporal0.395†0.2800.1130.2810.2880.1670.477‡0.3220.331F right hippocampus0.395†0.3070.0770.3250.3560.1900.486‡0.3570.339F right parietal0.376†0.2490.0820.2740.2830.1390.460†0.2550.311F right parahippocampal gyrus0.375†0.3530.1190.3020.3410.2410.3530.2080.273

† p < 0.05, ‡ p < 0.01, *FDR p < 0.05

Conclusion

These findings suggest that the BBB may be affected early in the course of cognitive dysfunction, even preceding detectable changes in other MRI sequences and machine learning algorithms can be used to predict TTS measures, even in asymptomatic SLE patients.

References

Nil.

Disclosure of Interests

Sen Hee Tay: None declared, Mary Stephenson: None declared, Nur Azizah Allameen: None declared, Sriram Narayanan: None declared, Bernett Lee: None declared, Anselm Mak Speakers bureau: JnJ Apr 2019 and GSK Jan 2022, Grant/research support from: GSK - The Supported Studies Programme

Microscopic Dynamics of Inverse Wormlike Micelles Probed Using X-ray Photon Correlation Spectroscopy

Wormlike micelles (WLMs) are ubiquitous viscoelastic modifiers that share properties with polymer solutions. While their macroscopic rheology is well-understood, their microscopic dynamics remain difficult to measure because they span a large range of time and length scales. In this work, we demonstrate the use of X-ray photon correlation spectroscopy to interrogate the segmental dynamics of inverse WLM solutions swollen with a rubidium chloride solution. We observe a diffusive scaling of the dynamics and extract a temperature-dependent diffusion coefficient, which we associate with the thermal interactions of the slow segmental dynamics near entanglement points. We probe this relaxation process across the unbranched to branched topological transition and find no microstructural evidence of branch formation in the slow mode. Instead, we observe that the dynamics become more homogeneous and prominent as the temperature is reduced and water content increases.

Search for low-mass dilepton resonances in Higgs boson decays to four-lepton final states in proton-proton collisions at s = 13 TeV

A search for low-mass dilepton resonances in Higgs boson decays is conducted in the four-lepton final state. The decay is assumed to proceed via a pair of beyond the standard model particles, or one such particle and a Z boson. The search uses proton-proton collision data collected with the CMS detector at the CERN LHC, corresponding to an integrated luminosity of 137 fb - 1 , at a center-of-mass energy s = 13 TeV . No significant deviation from the standard model expectation is observed. Upper limits at 95% confidence level are set on model-independent Higgs boson decay branching fractions. Additionally, limits on dark photon and axion-like particle production, based on two specific models, are reported.

Advancing Chemical Separations: Unraveling the Structure and Dynamics of Phase Splitting in Liquid-Liquid Extraction

Liquid-liquid extraction (LLE), the go-to process for a variety of chemical separations, is limited by spontaneous organic phase splitting upon sufficient solute loading, called third phase formation. In this study we explore the applicability of critical phenomena theory to gain insight into this deleterious phase behavior with the goal of improving separations efficiency and minimizing waste. A series of samples representative of rare earth purification were constructed to include each of one light and one heavy lanthanide (cerium and lutetium) paired with one of two common malonamide extractants (DMDOHEMA and DMDBTDMA). The resulting postextraction organic phases are chemically complex and often form rich hierarchical structures whose statics and dynamics near the critical point were probed herein with small-angle X-ray scattering and high-speed X-ray photon correlation spectroscopy. Despite their different extraction behaviors, all samples show remarkably similar critical behavior with exponents well described by classical critical point theory consistent with the 3D Ising model, where the critical behavior is characterized by fluctuations with a single diverging length scale. This unexpected result indicates a significant reduction in relevant chemical parameters at the critical point, indicating that the underlying behavior of phase transitions in LLE rely on far fewer variables than are generally assumed. The obtained scalar order parameter is attributed to the extractant fraction of the extractant/diluent mixture, revealing that other solution components and their respective concentrations simply shift the critical temperature but do not affect the nature of the critical fluctuations. These findings point to an opportunity to drastically simplify studies of liquid-liquid phase separation and phase diagram development in general while providing insights into LLE process improvement.

Using Z Boson Events to Study Parton-Medium Interactions in Pb-Pb Collisions

The spectra measurements of charged hadrons produced in the shower of a parton originating in the same hard scattering with a leptonically decaying Z boson are reported in lead-lead nuclei (Pb-Pb) and proton-proton (pp) collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV. Both Pb-Pb and pp data sets are recorded by the CMS experiment at the LHC and correspond to an integrated luminosity of 1.7  nb^{-1} and 320  pb^{-1}, respectively. Hadronic collision data with one reconstructed Z boson candidate with the transverse momentum p_{T}>30  GeV/c are analyzed. The Z boson constrains the initial energy and direction of the associated parton. In heavy ion events, azimuthal angular distributions of charged hadrons with respect to the direction of a Z boson are sensitive to modifications of the in-medium parton shower and medium response. compared to reference data from pp interactions, the results for central Pb-Pb collisions indicate a modification of the angular correlations. The measurements of the fragmentation functions and p_{T} spectra of charged particles in Z boson events, which are sensitive to medium modifications of the parton shower longitudinal structure, are also reported. Significant modifications in central Pb-Pb events compared to the pp reference data are also found for these observables.

Search for strongly interacting massive particles generating trackless jets in proton-proton collisions at s = 13 TeV

A search for dark matter in the form of strongly interacting massive particles (SIMPs) using the CMS detector at the LHC is presented. The SIMPs would be produced in pairs that manifest themselves as pairs of jets without tracks. The energy fraction of jets carried by charged particles is used as a key discriminator to suppress efficiently the large multijet background, and the remaining background is estimated directly from data. The search is performed using proton-proton collision data corresponding to an integrated luminosity of 16.1 fb - 1 , collected with the CMS detector in 2016. No significant excess of events is observed above the expected background. For the simplified dark matter model under consideration, SIMPs with masses up to 100 GeV are excluded and further sensitivity is explored towards higher masses.

Diffuse X-ray scattering from polished silicon: application of the distorted wave Born approximation

Measured diffuse X-ray scattering data for a `smooth' as well as for a `rough' silicon sample were fit to theoretical expressions within the distorted wave Born approximation (DWBA). Data for the power spectral density (PSD) for both samples were also obtained by means of atomic force microscopy and optical interferometry. The Fourier transforms of trial correlation functions were fit to the PSD data and then applied to the DWBA formalism. The net correlation functions needed to fit the PSD data for each sample comprised the sum of two terms with different cutoff lengths and different self-affine fractal exponents. At zero distance these correlation functions added up to yield net values of σ² = (2)² and (71)² Ų for the smooth and rough samples, respectively. X-ray scattering data were obtained at beamline 1-BM of the Advanced Photon Source. Data and fits at values of q_z = 0.05 and 0.10 Å^-1 for the smooth sample are reported. Good fits for the smooth sample were obtained at both q_z values simultaneously, that is, identical fitting parameters were applied at both values of q_z. The smooth sample also exhibited weak Yoneda wings and a clear distinction between the strong specular scattering and the weak diffuse scattering. Data for the rough sample were qualitatively different and exhibited very weak scattering at the specular condition in contrast to extremely large Yoneda wings. Fits for the rough sample are reported for q_z = 0.04, 0.05, and 0.06 Å^-1. Although the large Yoneda wings could be fit quite well in both position and amplitude, scattering near the specular condition could not be equally well fit by applying the same fitting parameters at all values of q_z. Albeit imperfect, best-fitting results at the specular condition were obtained by invoking only diffuse scattering, that is, without including a separate theoretical expression for specular scattering.

The Use of Kratom (Mitragyna speciosa Korth.) Among People Who Co-use Heroin and Methamphetamine in Malaysia

OBJECTIVES

Kratom (Mitragyna speciosa Korth.), an indigenous medicinal plant, has been widely used as a traditional remedy in Southeast Asia. However, its combined consumption with other substances has received scarce attention. This study investigates the use of kratom among adults with a history of using heroin and methamphetamine in Malaysia.

METHODS

A total of 332 patients who were mandated to undergo drug rehabilitation participated in this cross-sectional study. The study data were collected through face-to-face interviews using a semi-structured questionnaire.

RESULTS

The majority were males (95%, n = 314/332) and Malays (98%, n = 325/332) with a mean age of 32.3 years (SD = 9.16). Over two thirds of the respondents used kratom to alleviate heroin withdrawal symptoms and to reduce methamphetamine intake; 59% used it as a substitute for heroin and methamphetamine. A similar proportion used kratom to reduce heroin intake (58%), while only 15% used it for its euphoric effects. Multivariate analysis showed that previous attendees of government rehabilitation programs had lower odds of using kratom as a heroin substitute.

CONCLUSIONS

The potential of kratom to alleviate heroin withdrawal symptoms, and to reduce methamphetamine and heroin intake, among people who co-use heroin and methamphetamine warrants further research.

Evidence for X(3872) in Pb-Pb Collisions and Studies of its Prompt Production at sqrt[s_{NN}]=5.02 TeV

The first evidence for X(3872) production in relativistic heavy ion collisions is reported. The X(3872) production is studied in lead-lead (Pb-Pb) collisions at a center-of-mass energy of sqrt[s_{NN}]=5.02  TeV per nucleon pair, using the decay chain X(3872)→J/ψπ^{+}π^{-}→μ^{+}μ^{-}π^{+}π^{-}. The data were recorded with the CMS detector in 2018 and correspond to an integrated luminosity of 1.7  nb^{-1}. The measurement is performed in the rapidity and transverse momentum ranges |y|<1.6 and 15<p_{T}<50  GeV/c. The significance of the inclusive X(3872) signal is 4.2 standard deviations. The prompt X(3872) to ψ2S yield ratio is found to be ρ^{Pb-Pb}=1.08±0.49(stat)±0.52(syst), to be compared with typical values of 0.1 for pp collisions. This result provides a unique experimental input to theoretical models of the X(3872) production mechanism, and of the nature of this exotic state.

Factors associated with drug use during pregnancy and breastfeeding among females who use drugs (FWUDs) in Malaysia

Females who use drugs (FWUDs) are at risk of continuing illicit substance use during pregnancy and breastfeeding. We investigated the prevalence rates and factors associated with these practices in a sample of 200 FWUDs recruited from a publicly-run drug rehabilitation center. A semi-structured questionnaire was used to collect the data. The majority (86%) was Malay (n = 171/200), currently single (71%, n = 141/200), and 51% had nine years of education. The mean age of respondents was 32.2 years (SD = 8.61). Thirty-eight percent (n = 75/200) reported ever using illicit substances during pregnancy, while 15% (n = 30/200) had used them during breastfeeding. Higher odds of using drugs during pregnancy were associated with having an intimate male drug-using partner and with persons who reported abandoning an infant in the past. Lower odds were linked with women who used heroin with ATS (relative to those who used only ATS), and shorter-term ATS (≤3 years) relative to long term ATS users. At a lower level of significance (p = 0.054), being married also lowered the odds. Higher odds of drug use during breastfeeding were associated with having an intimate male drug-using partner, and previous methadone use history, while lower odds were associated with short-term ATS use and being employed. The findings highlight the need for timely and targeted interventions to inform, engage and promote the participation of FWUDs in pre- and post-natal care services.

Suboptimal uptake, retention, and adherence of daily oral PrEP among people with OUD receiving HCV treatment

Background

Daily oral preexposure prophylaxis (PrEP) with tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC) prevents human immunodeficiency (HIV) among people who inject drugs (PWID). Despite rising HIV incidence and injection drug use (IDU), PrEP use remains low and there is limited research about uptake, adherence, and retention among PWID.

Methods

The ANCHOR investigation evaluated a community-based care model collocating hepatitis C virus (HCV) treatment, medication for opioid use disorder (OUD), and PrEP in individuals in Washington, DC, and Baltimore, Maryland. PrEP counseling was conducted from HCV treatment day 0 until week 24. Subjects could start any time during this window, were followed for 48 weeks, and were assessed for adherence by self-report and dried blood spot TDF analysis.

Results

One hundred ninety-eight participants were enrolled, of whom 185 (93%) were HIV negative. Twenty-nine individuals (15.7% of HIV-negative cohort) initiated PrEP. One hundred sixteen participants (62.7%) met 2014 Centers for Disease Control and Prevention (CDC) PrEP criteria due to IDU (82 [44.3%]), sex (9 [4.9%]), or both practices (25 [13.5%]). Providers recommended PrEP to 94 individuals (50.8%), and recommendation was associated with PrEP uptake. Median treatment duration was 104 days (interquartile range, 28–276 days), with 8 participants retained through week 48. Adherence was variable over time by self-report and declined by TDF analysis. No HIV seroconversions occurred.

Conclusions

This cohort of people with HCV and OUD experienced low uptake of PrEP despite the majority meeting CDC criteria. High rates of disruption and discontinuation, compounded by variable adherence, made TDF/FTC a suboptimal prevention strategy. Emerging modalities like long-acting formulations may address these barriers, but PWID have been excluded from their development to date.

Microbial fermentation of Fossence™, a short-chain fructo-oligosaccharide, under simulated human proximal colonic condition and assessment of its prebiotic effects-a pilot study

A short-chain fructo-oligosaccharide (sc-FOS) was tested in a simulator of the human gut microbial ecosystem (SHIME) in vitro model to quantify its prebiotic effects according to Prebiotic Index (PI) and Measure of prebiotic effect (MPE) equations. FossenceTM, (sc-FOS, 0.5%) was fermented in a simulated human proximal colonic condition, using a fecal inoculum from a healthy individual. We analysed the pH reduction, substrate utilization, lactate and short-chain fatty acid (SCFA) production and microbial community modulation. Microbial fermentation of sc-FOS strongly reduced the media pH indicating the production of lactate and SCFA with accumulation of lactate and enhanced levels of acetate (34.38 ± 0.38 mM), propionate (20.93 ± 0.56 mM) and butyrate (4.93 ± 0.03 mM) compared to 18.46 ± 0.20 mM, 6.24 ± 0.10 mM and 3.3 ± 0.06 mM in the blank, respectively. Total SCFA production in test media was 61.91 ± 0.87 mM compared to 33.65 ± 0.36 mM in blank and the contribution of free-sugars present in sc-FOS to SCFAs was negligible. Modulation of the microbial community was analysed through 16S rRNA sequencing and we found that sc-FOS greatly stimulated the beneficial bacteria such as Bifidobacteria and Lactobacillus. We report the PI and MPE values for FossenceTM, as 14.9 and 0.01 respectively at the end of 24 h, which is an indicator of a strong prebiotic effect.

1063 Incidence, Risk Factors, and Outcomes of ARDS in Patients with SARS-CoV-2 Infection

Introduction

Many asymptomatic patients are diagnosed with SARS-CoV-2 infection on screening, which might alter their expected course of illness. We wanted to study the incidence, risk factors, and ARDS outcomes in these patients admitted to our ITU.

Method

A review of all admissions (medical, surgical, and obstetric) to our ITU from May to October 2020 was done after institutional ethics approval. Age, gender, comorbidities, admission diagnosis, APACHE II score, and in-hospital course were studied. ARDS was defined as PaO2/FiO2 ≤ 300 mmHg (with PEEP or CPAP ≥ 5 cmH2O) in the absence of cardiac failure or fluid overload. Data were analyzed using Statistical Package for Social Services (SPSS) software Version 21.0 (Armonk, NY: IBM Corp).

Results

Of the 832 cases, 119 (14.3%) had SARS-CoV-2 infection. 41 of 119 (34.4%) cases developed ARDS. Among the comorbidities studied, only hypertension (OR 2.6, 95% CI 1.0-6.2) seemed to increase ARDS odds. Patients with Severe Acute Respiratory Illness (SARI) had a higher incidence of ARDS when compared to the asymptomatic ones (P &lt; .05). Patients with sepsis (OR 5.8, 95% CI 2.4-13.7) and APACHE II score ≥10 (OR 5, 95% CI 2.0-12.3) had higher odds of developing ARDS. Age, gender, trauma, and recent surgery did not seem to increase the risk of ARDS.

Conclusions

Even though COVID-19 patients admitted with SARI and sepsis are at a higher risk of developing ARDS, further research will be needed to predict the extent to which SARS-CoV-2 infection will influence the course of their illness.

Morbidity, mortality, and emerging drug resistance in Device-associated infections (DAIs) in intensive care patients at a 1000-bedded tertiary care teaching hospital

Background

Device-associated infections (DAIs) such as ventilator associated pneumonia (VAP), central line-associated blood stream infection (CLABSI), and catheter-related urinary tract infection (CAUTI) are principal contributors to health hazard and a major preventable threat to patient safety. Robust surveillance of DAI delineates infections, pathogens, resistograms, and facilitates antimicrobial therapy, infection-control, antimicrobial stewardship, and improvement in quality of care.

Methods

This prospective outcome surveillance study was conducted amongst 2067 ICU patients in a 1000-bedded teaching hospital. Clinical, laboratory, and environmental surveillance, as well as screening of health care professionals (HCPs) were conducted using the modified US Centers for Disease Control and Prevention-National Healthcare Safety Network definitions and methods. Morbidity, mortality, and health-care indices were analyzed and two-tier infection prevention and control was promulgated.

Results

Mean occupancy was 95.34% for 2061 patients of 7381 patients/bed/ICU days. One hundred seventeen episodes of DAI occurred in 1258 patients of 12,882 device-days with mean device utilization ratio of 1.79. Mean rate of DAI was 7.40 per 1000 device days. Multiresistant Pseudomonas aeruginosa was most commonly followed by Acinetobacter. Mean all-cause mortality in ICU was 24.85%, whereas all-cause mortality after DAI was 9.79%. Methicillin-resistant Staphylococcus aureus prevalence was 38.46% amongst health-care professionals.

Conclusion

Mean rates of VAP, CLABSI, and CAUTI were 20.69, 2.53, and 2.23 per 1000 device days comparable with Indian and global ICUs. Resolute conviction and sustained momentum in infection prevention and control is an essential step toward patient safety.

Measurements of angular distance and momentum ratio distributions in three-jet and Z + two-jet final states in pp collisions

Collinear (small-angle) and large-angle, as well as soft and hard radiations are investigated in three-jet and Z  + two-jet events collected in proton-proton collisions at the LHC. The normalized production cross sections are measured as a function of the ratio of transverse momenta of two jets and their angular separation. The measurements in the three-jet and Z  + two-jet events are based on data collected at a center-of-mass energy of 8 TeV , corresponding to an integrated luminosity of 19.8 fb - 1 . The Z  + two-jet events are reconstructed in the dimuon decay channel of the Z  boson. The three-jet measurement is extended to include s = 13 TeV data corresponding to an integrated luminosity of 2.3 fb - 1 . The results are compared to predictions from event generators that include parton showers, multiple parton interactions, and hadronization. The collinear and soft regions are in general well described by parton showers, whereas the regions of large angular separation are often best described by calculations using higher-order matrix elements.