Tag: pubmed

Chaos. 2023 Sep 1;33(9):093102. doi: 10.1063/5.0154157.

ABSTRACT

The Fermi-Pasta-Ulam-Tsingou (FPUT) problem addresses fundamental questions in statistical physics, and attempts to understand the origin of recurrences in the system have led to many great advances in nonlinear dynamics and mathematical physics. In this work, we revisit the problem and study quasiperiodic recurrences in the weakly nonlinear α-FPUT system in more detail. We aim to reconstruct the quasiperiodic behavior observed in the original paper from the canonical transformation used to remove the three-wave interactions, which is necessary before applying the wave turbulence formalism. We expect the construction to match the observed quasiperiodicity if we are in the weakly nonlinear regime. Surprisingly, in our work, we find that this is not always the case and in particular, the recurrences observed in the original paper cannot be constructed by our method. We attribute this disagreement to the presence of small denominators in the canonical transformation used to remove the three-wave interactions before arriving at the starting point of wave turbulence. We also show that these small denominators are present even in the weakly nonlinear regime, and they become more significant as the system size is increased. We also discuss our results in the context of the problem of equilibration in the α-FPUT system and point out some mathematical challenges when the wave turbulence formalism is applied to explain thermalization in the α-FPUT problem. We argue that certain aspects of the α-FPUT system such as thermalization in the thermodynamic limit and the cause of quasiperiodicity are not clear, and that they require further mathematical and numerical studies.

PMID:37656916 | DOI:10.1063/5.0154157

Phys Rev Lett. 2023 Aug 18;131(7):071901. doi: 10.1103/PhysRevLett.131.071901.

ABSTRACT

An amplitude analysis of the B^{+}→D_{s}^{+}D_{s}^{-}K^{+} decay is carried out to study for the first time its intermediate resonant contributions, using proton-proton collision data collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV. A near-threshold peaking structure, referred to as X(3960), is observed in the D_{s}^{+}D_{s}^{-} invariant-mass spectrum with significance greater than 12 standard deviations. The mass, width, and the quantum numbers of the structure are measured to be 3956±5±10 MeV, 43±13±8 MeV, and J^{PC}=0^{++}, respectively, where the first uncertainties are statistical and the second systematic. The properties of the new structure are consistent with recent theoretical predictions for a state composed of cc[over ¯]ss[over ¯] quarks. Evidence for an additional structure is found around 4140 MeV in the D_{s}^{+}D_{s}^{-} invariant mass, which might be caused either by a new resonance with the 0^{++} assignment or by a J/ψϕ↔D_{s}^{+}D_{s}^{-} coupled-channel effect.

PMID:37656865 | DOI:10.1103/PhysRevLett.131.071901

J Med Internet Res. 2023 Sep 1;25:e45262. doi: 10.2196/45262.

ABSTRACT

BACKGROUND: Men who have sex with men (MSM) in China hold a low-risk perception of acquiring HIV. This has resulted in an inadequate HIV testing rate.

OBJECTIVE: This study aims to investigate whether administering HIV risk self-assessments with tailored feedback on a gay geosocial networking (GSN) app could improve HIV testing rates and reduce sexual risk behaviors in Chinese MSM.

METHODS: We recruited MSM from Beijing, China, who used the GSN platform Blued in October 2017 in this 12-month double-blinded randomized controlled trial. From October 2017 to September 2018, eligible participants were randomly assigned to use a self-reported HIV risk assessment tool that provided tailored feedback according to transmission risk (group 1), access to the same HIV risk assessment without feedback (group 2), or government-recommended HIV education materials (control). All interventions were remotely delivered through the mobile phone-based app Blued, and participants were followed up at 1, 3, 6, and 12 months from baseline. The number of HIV tests over the 12-month study was the primary outcome and was assessed using an intention-to-treat analysis with an incident rate ratio (IRR). Unprotected anal intercourse (UAI) over 6 months was assessed by a modified intention-to-treat analysis and was the secondary outcome. All statistical analyses were conducted in SAS 9.3 (SAS Institute, Inc.), and a P value <.05 was considered statistically significant.

RESULTS: In total, 9280 MSM were recruited from baseline and were randomly assigned to group 1 (n=3028), group 2 (n=3065), or controls (n=3187). After follow-up, 1034 (34.1%), 993 (32.4%), and 1103 (34.6%) remained in each group, respectively. Over 12 months, group 1 took 391 tests (mean of 2.51 tests per person), group 2 took 352 tests (mean of 2.01 tests per person), and controls took 295 tests (mean of 1.72 tests per person). Group 1 had significantly more HIV testing than the control group (IRR 1.32, 95% CI 1.09-4.58; P=.01), while group 2 did not differ significantly from the controls (IRR 1.06, 95% CI 0.86-1.30; P=.60). The proportion of UAI was not statistically different among different groups, but all 3 groups had UAI, which declined from baseline.

CONCLUSIONS: Repeated HIV risk assessments coupled with tailored feedback through GSN apps improved HIV testing. Such interventions should be considered a simple way of improving HIV testing among MSM in China and increasing awareness of HIV status.

TRIAL REGISTRATION: ClinicalTrials.gov NCT03320239; https://clinicaltrials.gov/study/NCT03320239.

PMID:37656500 | DOI:10.2196/45262

J Med Internet Res. 2023 Sep 1;25:e43883. doi: 10.2196/43883.

ABSTRACT

BACKGROUND: Providing informed consent means agreeing to participate in a clinical trial and having understood what is involved. Flawed informed consent processes, including missing dates and signatures, are common regulatory audit findings. Electronic consent (eConsent) uses digital technologies to enable the consenting process. It aims to improve participant comprehension and engagement with study information and to address data quality concerns.

OBJECTIVE: This systematic literature review aimed to assess the effectiveness of eConsent in terms of patient comprehension, acceptability, usability, and study enrollment and retention rates, as well as the effects of eConsent on the time patients took to perform the consenting process (“cycle time”) and on-site workload in comparison with traditional paper-based consenting.

METHODS: The systematic review was conducted and reported in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Ovid Embase and Ovid MEDLINE were systematically searched for publications reporting original, comparative data on the effectiveness of eConsent in terms of patient comprehension, acceptability, usability, enrollment and retention rates, cycle time, and site workload. The methodological validity of the studies that compared outcomes for comprehension, acceptability, and usability across paper consent and eConsent was assessed. Study methodologies were categorized as having “high” validity if comprehensive assessments were performed using established instruments.

RESULTS: Overall, 37 publications describing 35 studies (13,281 participants) were included. All studies comparing eConsenting and paper-based consenting for comprehension (20/35, 57% of the studies; 10 with “high” validity), acceptability (8/35, 23% of the studies; 1 with “high” validity), and usability (5/35, 14% of the studies; 1 with “high” validity) reported significantly better results with eConsent, better results but without significance testing, or no significant differences in overall results. None of the studies reported better results with paper than with eConsent. Among the “high” validity studies, 6 studies on comprehension reported significantly better understanding of at least some concepts, the study on acceptability reported statistically significant higher satisfaction scores, and the study on usability reported statistically significant higher usability scores with eConsent than with paper (P<.05 for all). Cycle times were increased with eConsent, potentially reflecting greater patient engagement with the content. Data on enrollment and retention were limited. Comparative data from site staff and other study researchers indicated the potential for reduced workload and lower administrative burden with eConsent.

CONCLUSIONS: This systematic review showed that compared with patients using paper-based consenting, patients using eConsent had a better understanding of the clinical trial information, showed greater engagement with content, and rated the consenting process as more acceptable and usable. eConsent solutions thus have the potential to enhance understanding, acceptability, and usability of the consenting process while inherently being able to address data quality concerns, including those related to flawed consenting processes.

PMID:37656499 | DOI:10.2196/43883

JMIR Public Health Surveill. 2023 Sep 1;9:e42495. doi: 10.2196/42495.

ABSTRACT

BACKGROUND: The recent pandemic had the potential to worsen the opioid crisis through multiple effects on patients’ lives, such as the disruption of care. In particular, good levels of adherence with respect to medication for opioid use disorder (MOUD), recognized as being important for positive outcomes, may be disrupted.

OBJECTIVE: This study aimed to investigate whether patients on MOUD experienced a drop in medication adherence during the recent COVID-19 pandemic.

METHODS: This retrospective cohort study used Medicaid claims data from 6 US states from 2018 until the start of 2021. We compared medication adherence for people on MOUD before and after the beginning of the COVID-19 pandemic in March 2020. Our main measure was the proportion of days covered (PDC), a score that measures patients’ adherence to their MOUD. We carried out a breakpoint analysis on PDC, followed by a patient-level beta regression analysis with PDC as the dependent variable while controlling for a set of covariates.

RESULTS: A total of 79,991 PDC scores were calculated for 37,604 patients (age: mean 37.6, SD 9.8 years; sex: n=17,825, 47.4% female) between 2018 and 2021. The coefficient for the effect of COVID-19 on PDC score was -0.076 and was statistically significant (odds ratio 0.925, 95% CI 0.90-0.94).

CONCLUSIONS: The COVID-19 pandemic was negatively associated with patients’ adherence to their medication, which had declined since the beginning of the pandemic.

PMID:37656492 | DOI:10.2196/42495

Dtsch Arztebl Int. 2023 Oct 27;(Forthcoming):arztebl.m2023.0191. doi: 10.3238/arztebl.m2023.0191. Online ahead of print.

ABSTRACT

BACKGROUND: In this systematic review, we address the question whether children and adolescents with developmental visual disorders benefit from computer-assisted visual training.

METHODS: Systematic literature searches were carried out in three bibliographic databases (initial search in October 2021) and trial registries. Included were randomized controlled trials that evaluated the efficacy of computer-assisted visual training in children and adolescents with developmental visual disorders in comparison to no training, sham training, or conservative treatment.

RESULTS: The inclusion criteria were met by 17 trials (with a total of 1323 children and adolescents) focusing on binocular or monocular computer-assisted visual training for the treatment of amblyopia. In these trials, visual training was carried out for 2 to 24 weeks, either as “stand alone” therapy or in addition to occlusion therapy. Six trials showed a statistically significant difference in favor of the visual training for the outcome “best corrected visual acuity of the amblyopic eye.” However, this difference was small and mostly below the threshold of clinical relevance of -0.05 logMAR (equivalent to an improvement of 0.5 lines on the eye chart, or 2.5 letters per line). Only few data were available for the outcomes “binocular vision” and “adverse events”; the differences between the groups were similarly small.

CONCLUSION: The currently available data do not permit any firm conclusions regarding the efficacy of visual training in children and adolescents with amblyopia. Moreover, treatment adherence was often insufficient and the treatment durations in the trials was relatively short. No results from randomized trials have yet been published with respect to other developmental visual disorders (refractive errors, strabismus).

PMID:37656479 | DOI:10.3238/arztebl.m2023.0191

JAMA Health Forum. 2023 Sep 1;4(9):e232875. doi: 10.1001/jamahealthforum.2023.2875.

ABSTRACT

IMPORTANCE: Vertical relationships (eg, ownership or affiliations, including joint contracting) between physicians and health systems are increasing in the US.

OBJECTIVE: To analyze how vertical relationships between primary care physicians (PCPs) and large health systems are associated with changes in ambulatory and acute care utilization, referral patterns, readmissions, and total medical spending for commercially insured individuals.

DESIGN, SETTING, AND PARTICIPANTS: This case-control study with a repeated cross-section, stacked event design analyzed outcomes of patients whose attributed PCP entered a vertical relationship with a large health care system in 2015 or 2017 compared with patients whose attributed PCP was either never or always in a vertical relationship with a large health system from 2013 to 2017 in the state of Massachusetts. The sample consisted of commercially insured patients who met enrollment criteria and who were attributed to PCPs who were included in the Massachusetts Provider Database in 2013, 2015, and 2017 and for whom vertical relationships were measured. Enrollee and claims data were obtained from the 2013 to 2017 Massachusetts All-Payer Claims Database. Statistical analyses were conducted between January 5, 2021, and June 5, 2023.

EXPOSURE: Evaluation-and-management visit with attributed PCP in 2015 to 2017.

MAIN OUTCOMES AND MEASURES: Outcomes (which were measured per patient-year [ie, per patient per year from January to December] in this sample) were utilization (count of specialist physician visits, emergency department [ED] visits, and hospitalizations overall and within attributed PCP’s health system), spending (total medical expenditures and use of high-price hospitals), and readmissions (readmission rate and use of hospitals with a low readmission rate).

RESULTS: The sample of 4 030 224 observations included 2 147 303 females (53.3%) and 1 881 921 males (46.7%) with a mean (SD) age of 35.07 (19.95) years. Vertical relationships between PCPs and large health systems were associated with an increase of 0.69 (95% CI, 0.34-1.04; P < .001) in specialist visits per patient-year, a 22.64% increase vs the comparison group mean of 3.06 visits, and a $356.67 (95% CI, $77.16-$636.18; P = .01) increase in total medical expenditures per patient-year, a 6.26% increase vs the comparison group mean of $5700.07. Within the health care system of the attributed PCPs, the number of specialist visits changed by 0.80 (95% CI, 0.56-1.05) per patient year (P < .001), a 29.38% increase vs the comparison group mean of 2.73 specialist visits per patient-year. The number of ED visits changed by 0.02 (95% CI, 0.01-0.03) per patient year (P = .001), a 14.19% increase over the comparison group mean of 0.15 ED visits per patient-year. The number of hospitalizations changed by 0.01 (95% CI, 0.00-0.01) per patient-year (P < .001), a 22.36% increase over the comparison group mean of 0.03 hospitalizations per patient-year. There were no differences in readmission outcomes.

CONCLUSIONS: Results of this case-control study suggest that vertical relationships between PCPs and large health systems were associated with steering of patients into health systems and increased spending on patient care, but no difference in readmissions was found.

PMID:37656471 | DOI:10.1001/jamahealthforum.2023.2875

Vet Med Sci. 2023 Sep 1. doi: 10.1002/vms3.1255. Online ahead of print.

ABSTRACT

BACKGROUND: The expectancy of Toxoplasma gondii transmitted from livestock and raw meat to humans is a public health problem and is an example of the One Health theory.

OBJECTIVES: This survey aimed to determine the seroprevalence and risk factors related to this common infection in individuals occupationally exposed (IOE) to livestock, raw meat and viscera in industrial slaughterhouses and livestock fields in Isfahan province, central Iran.

METHODS: This study is a case-control survey carried out on the 401 serum samples of IOE (including slaughterhouse workers, butchers, veterinarians, veterinary technicians, livestock farmers and farm workers) compared to 401 archived samples of the general population (that all matched with cases by region, age and gender). All 802 samples were investigated for anti-T. gondii IgM and anti-T. gondii IgG using enzyme-linked immunosorbent assay.

RESULTS: A statistically significant higher anti-T. gondii IgG occurrence (p < 0.001) was observed in IOE compared to the control group (46.1% vs. 31.4%). According to our knowledge, this is the first case-control study on the seroprevalence of anti-T. gondii in IOE to livestock in central Iran.

CONCLUSIONS: These findings show a potentially significant association between T. gondii seropositivity and occupational exposure to livestock. Therefore, it is essential to develop guidelines for preventing disease transmission among IOE to livestock, raw meat and viscera in industrial slaughterhouses and livestock fields.

PMID:37656467 | DOI:10.1002/vms3.1255

Transl Vis Sci Technol. 2023 Sep 1;12(9):1. doi: 10.1167/tvst.12.9.1.

ABSTRACT

PURPOSE: The purpose of this study was to determine the impact of prophylactic ranibizumab (PR) injections given every 3 months in eyes with intermediate nonexudative age-related macular degeneration (AMD) on drusen volume, macular layer thicknesses, and progression of geographic atrophy (GA) area over 24 months in the PREVENT trial.

METHODS: This post hoc analysis of the prospective PREVENT trial compared eyes with intermediate AMD randomized to PR versus sham injections to determine rates of conversion to neovascular AMD over 24 months. Drusen area and volume, macular thickness and volume, and retinal layer thicknesses were measured on spectral-domain optical coherence tomography images and analyzed. Masked grading of GA area and subretinal drusenoid deposits (SDDs) using fundus autofluorescence images was performed.

RESULTS: There were no statistical differences in drusen area and volumes between groups, and similar reductions in central subfield thickness, mean cube thickness, cube volume, and retinal sublayer thickness from baseline to 24 months (P = 0.018 to < 0.001), with no statistical differences between groups in any of these anatomic parameters. These findings were not impacted by the presence or absence of SDD. Among the 9 eyes with GA in this study, mean GA growth rate from baseline to 24 months was 1.34 +/- 0.79 mm2/year after PR and 1.95 +/- 1.73 mm2/year in sham-treated eyes (P = 0.49), and similarly showed no statistical difference with square root transformation (P = 0.61).

CONCLUSIONS: Prophylactic ranibizumab given every 3 months did not appear to affect drusen volume, macular thinning, or GA progression in eyes with intermediate AMD.

TRANSLATIONAL RELEVANCE: This work investigates the impact of PR on progressive retinal degeneration in a clinical trial.

PMID:37656449 | DOI:10.1167/tvst.12.9.1

Int J Clin Exp Hypn. 2023 Sep 1:1-16. doi: 10.1080/00207144.2023.2249047. Online ahead of print.

ABSTRACT

Approximately two out of three college students report experiencing suboptimal sleep quality. The aim of this study was to examine the feasibility of a self-administered hypnosis intervention to improve sleep in college students. Twenty-two college students who self-reported poor sleep quality were enrolled in a 4-week study comprising 1 baseline week and a 3-week self-administered hypnosis intervention. Sleep onset latency and sleep efficiency as measured by wrist actigraphy were significantly improved. The mean average nightly sleep duration during the baseline week was 398.88 minutes (SD = 56.44), which increased to a mean of 413.88 minutes (SD = 57.80) during the 3rd week of intervention. However, the results show that there was no statistically significant difference between weeks on objective nightly sleep duration, 95% CI [-11.13, 41.13], t(15) = 1.224, p = .240. Also, results showed that there was no significant difference between weeks on self-reported nightly sleep duration, F(3, 57) = 2.155, p = .103. Twenty participants (91%) completed the study intervention and adherence to daily self-hypnosis practice with an audio recording was high. Zero study-related adverse events were reported, and participants perceived the intervention as easy to use and helpful for improving sleep. These results provide evidence for the feasibility and safety of a self-administered hypnosis intervention to improve sleep in college students. A larger randomized clinical trial is warranted to determine efficacy.

PMID:37656440 | DOI:10.1080/00207144.2023.2249047