Category: Nevin Manimala

Phys Rev Lett. 2022 Jul 15;129(3):034101. doi: 10.1103/PhysRevLett.129.034101.

ABSTRACT

The present work considers systems whose dynamics are governed by the nonlinear interactions among groups of 6 nonlinear waves, such as those described by the unforced quintic nonlinear Schrödinger equation. Specific parameter regimes in which ensemble-averaged dynamics of such systems with finite size are accurately described by a wave kinetic equation, as used in wave turbulence theory, are theoretically predicted. In addition, the underlying reasons that the wave kinetic equation may be a poor predictor of wave dynamics outside these regimes are also discussed. These theoretical predictions are directly verified by comparing ensemble averages of solutions to the dynamical equation with corresponding solutions of the wave kinetic equation.

PMID:35905369 | DOI:10.1103/PhysRevLett.129.034101

Phys Rev Lett. 2022 Jul 15;129(3):034502. doi: 10.1103/PhysRevLett.129.034502.

ABSTRACT

Processes leading to anomalous fluctuations in turbulent flows, referred to as intermittency, are still challenging. We consider cascade trajectories through scales as realizations of a stochastic Langevin process for which multiplicative noise is an intrinsic feature of the turbulent state. The trajectories are conditioned on their entropy exchange. Such selected trajectories concentrate around an optimal path, called instanton, which is the minimum of an effective action. The action is derived from the Langevin equation, estimated from measured data. In particular instantons with negative entropy pinpoint the trajectories responsible for the emergence of non-Gaussian statistics at small scales.

PMID:35905359 | DOI:10.1103/PhysRevLett.129.034502

Phys Rev Lett. 2022 Jul 15;129(3):030503. doi: 10.1103/PhysRevLett.129.030503.

ABSTRACT

Phase estimation is a quantum algorithm for measuring the eigenvalues of a Hamiltonian. We propose and rigorously analyze a randomized phase estimation algorithm with two distinctive features. First, our algorithm has complexity independent of the number of terms L in the Hamiltonian. Second, unlike previous L-independent approaches, such as those based on qDRIFT, all algorithmic errors in our method can be suppressed by collecting more data samples, without increasing the circuit depth.

PMID:35905339 | DOI:10.1103/PhysRevLett.129.030503

Int J Cancer. 2022 Jul 29. doi: 10.1002/ijc.34230. Online ahead of print.

ABSTRACT

Data on diet and survival among people with metastatic colorectal cancer are limited. We examined dietary fat in relation to all-cause mortality and cancer progression or death among 1,149 people in the Cancer and Leukemia Group B (Alliance)/Southwest Oncology Group (SWOG) 80405 trial who completed a food frequency questionnaire at initiation of treatment for advanced or metastatic colorectal cancer. We examined saturated; monounsaturated; total and specific types (n-3, long-chain n-3, and n-6) of polyunsaturated fat; animal; and vegetable fats. We hypothesized higher vegetable fat intake would be associated with lower risk of all-cause mortality and cancer progression. We used Cox proportional hazards regression to estimate adjusted hazard ratios (HR) and 95% confidence intervals (CI). Over median follow-up of 6.1 years [interquartile range (IQR): 5.3, 7.2 y], we observed 974 deaths and 1,077 events of progression or death. Participants had a median age of 59 y; 41% were female and 86% identified as White. Moderate or higher vegetable fat was associated with lower risk of mortality and cancer progression or death [HRs comparing 2^nd , 3^rd , and 4^th to 1^st quartile for all-cause mortality: 0.74 (0.62, 0.90); 0.75 (0.61, 0.91); 0.79 (0.63, 1.00); p-trend: 0.12; for cancer progression or death: 0.74 (0.62, 0.89); 0.78 (0.64, 0.95); 0.71 (0.57, 0.88); p-trend: 0.01]. No other fat type was associated with all-cause mortality and cancer progression or death. Moderate or higher vegetable fat intake may be associated with lower risk of cancer progression or death among people with metastatic colorectal cancer.

PMID:35904874 | DOI:10.1002/ijc.34230

JMIR Form Res. 2022 Jul 29;6(7):e37189. doi: 10.2196/37189.

ABSTRACT

BACKGROUND: As more people are surviving stroke, there is a growing need for services and programs that support the long-term needs of people living with the effects of stroke. Exercise has many benefits; however, most people with stroke do not have access to specialized exercise programs that meet their needs in their communities. To catalyze the implementation of these programs, our team developed the Stroke Recovery in Motion Implementation Planner, an evidence-informed implementation guide for teams planning a community-based exercise program for people with stroke.

OBJECTIVE: This study aimed to conduct a user evaluation to elicit user perceptions of the usefulness and acceptability of the Planner to inform revisions.

METHODS: This mixed methods study used a concurrent triangulation design. We used purposive sampling to enroll a diverse sample of end users (program managers and coordinators, rehabilitation health partners, and fitness professionals) from three main groups: those who are currently planning a program, those who intend to plan a program in the future, and those who had previously planned a program. Participants reviewed the Planner and completed a questionnaire and interviews to identify positive features, areas of improvement, value, and feasibility. We used descriptive statistics for quantitative data and content analysis for qualitative data. We triangulated the data sources to identify Planner modifications.

RESULTS: A total of 39 people participated in this study. Overall, the feedback was positive, highlighting the value of the Planner’s comprehensiveness, tools and templates, and real-world examples. The identified areas for improvement included clarifying the need for specific steps, refining navigation, and creating more action-oriented content. Most participants reported an increase in knowledge and confidence after reading the Planner and reported that using the resource would improve their planning approach.

CONCLUSIONS: We used a rigorous and user-centered process to develop and evaluate the Planner. End users indicated that it is a valuable resource and identified specific changes for improvement. The Planner was subsequently updated and is now publicly available for community planning teams to use in the planning and delivery of evidence-informed, sustainable, community-based exercise programs for people with stroke.

PMID:35904870 | DOI:10.2196/37189

J Med Internet Res. 2022 Jul 29;24(7):e34669. doi: 10.2196/34669.

ABSTRACT

BACKGROUND: Consumer-grade wearable devices enable detailed recordings of heart rate and step counts in free-living conditions. Recent studies have shown that summary statistics from these wearable recordings have potential uses for longitudinal monitoring of health and disease states. However, the relationship between higher resolution physiological dynamics from wearables and known markers of health and disease remains largely uncharacterized.

OBJECTIVE: We aimed to derive high-resolution digital phenotypes from observational wearable recordings and to examine their associations with modifiable and inherent markers of cardiometabolic disease risk.

METHODS: We introduced a principled framework to extract interpretable high-resolution phenotypes from wearable data recorded in free-living conditions. The proposed framework standardizes the handling of data irregularities; encodes contextual information regarding the underlying physiological state at any given time; and generates a set of 66 minimally redundant features across active, sedentary, and sleep states. We applied our approach to a multimodal data set, from the SingHEART study (NCT02791152), which comprises heart rate and step count time series from wearables, clinical screening profiles, and whole genome sequences from 692 healthy volunteers. We used machine learning to model nonlinear relationships between the high-resolution phenotypes on the one hand and clinical or genomic risk markers for blood pressure, lipid, weight and sugar abnormalities on the other. For each risk type, we performed model comparisons based on Brier scores to assess the predictive value of high-resolution features over and beyond typical baselines. We also qualitatively characterized the wearable phenotypes for participants who had actualized clinical events.

RESULTS: We found that the high-resolution features have higher predictive value than typical baselines for clinical markers of cardiometabolic disease risk: the best models based on high-resolution features had 17.9% and 7.36% improvement in Brier score over baselines based on age and gender and resting heart rate, respectively (P<.001 in each case). Furthermore, heart rate dynamics from different activity states contain distinct information (maximum absolute correlation coefficient of 0.15). Heart rate dynamics in sedentary states are most predictive of lipid abnormalities and obesity, whereas patterns in active states are most predictive of blood pressure abnormalities (P<.001). Moreover, in comparison with standard measures, higher resolution patterns in wearable heart rate recordings are better able to represent subtle physiological dynamics related to genomic risk for cardiometabolic disease (improvement of 11.9%-22.0% in Brier scores; P<.001). Finally, illustrative case studies reveal connections between these high-resolution phenotypes and actualized clinical events, even for borderline profiles lacking apparent cardiometabolic risk markers.

CONCLUSIONS: High-resolution digital phenotypes recorded by consumer wearables in free-living states have the potential to enhance the prediction of cardiometabolic disease risk and could enable more proactive and personalized health management.

PMID:35904853 | DOI:10.2196/34669

Int J Oral Maxillofac Implants. 2022 Jul-Aug;37(4):823-829. doi: 10.11607/jomi.9382.

ABSTRACT

PURPOSE: Since flap advancement is a prerequisite for tension-free primary closure and successful regenerative procedures, the aim of this study was to test the efficacy of six surgical approaches for flap advancement in an ex vivo porcine model.

MATERIALS AND METHODS: A total of 60 fresh mandibles from pigs were randomized into one of six groups: (1) trapezoidal full-thickness flap design with two vertical releasing incisions (control), (2) trapezoidal flap with linear periosteal scoring, (3) mucosal detachment technique, (4) mucosal detachment with horizontal extension, (5) mucosal detachment with horizontal and vertical extension, and (6) mucosal detachment with horizontal vertical and cutback extension. Coronal advancement of the flap was recorded as the primary variable; the surface area of exposed mucosa and the tear strength were recorded as secondary variables.

RESULTS: Homogeneity existed among groups for preoperative keratinized tissue width and tissue thickness. Mucosal detachment with horizontal, vertical, and, cutback extensions achieved the highest amount of advancement. All remaining groups achieved a statistically higher advancement compared with the trapezoidal full-thickness flap (control). Pairwise comparison demonstrated statistical significance between any two groups (P < .001). A positive correlation was noted between exposed mucosa and flap advancement; the advancement increased 0.62 mm for each 10 mm² of increase in the exposed mucosal surface. Strength at tear stress was the highest in the trapezoidal full-thickness flap (control) and mucosal detachment with horizontal-vertical-cutback incisions (P < .001).

CONCLUSION: Coronal flap advancement was maximized in the mucosal detachment techniques and positively correlated with the area of exposed mucosa.

PMID:35904840 | DOI:10.11607/jomi.9382

JMIR Ment Health. 2022 Jul 29;9(7):e34254. doi: 10.2196/34254.

ABSTRACT

BACKGROUND: Rates of mental health problems among youth are high and rising, whereas treatment seeking in this population remains low. Technology-delivered interventions (TDIs) appear to be promising avenues for broadening the reach of evidence-based interventions for youth well-being. However, to date, meta-analytic reviews on youth samples have primarily been limited to computer and internet interventions, whereas meta-analytic evidence on mobile TDIs (mTDIs), largely comprising mobile apps for smartphones and tablets, have primarily focused on adult samples.

OBJECTIVE: This study aimed to evaluate the effectiveness of mTDIs for a broad range of well-being outcomes in unselected, at-risk, and clinical samples of youth.

METHODS: The systematic review used 5 major search strategies to identify 80 studies evaluating 83 wellness- and mental health-focused mTDIs for 19,748 youth (mean age 2.93-26.25 years). We conducted a 3-level meta-analysis on the full sample and a subsample of the 38 highest-quality studies.

RESULTS: Analyses demonstrated significant benefits of mTDIs for youth both at posttest (g=0.27) and follow-up (range 1.21-43.14 weeks; g=0.26) for a variety of psychosocial outcomes, including general well-being and distress, symptoms of diverse psychological disorders, psychosocial strategies and skills, and health-related symptoms and behaviors. Effects were significantly moderated by the type of comparison group (strongest for no intervention, followed by inert placebo or information-only, and only marginal for clinical comparison) but only among the higher-quality studies. With respect to youth characteristics, neither gender nor pre-existing mental health risk level (not selected for risk, at-risk, or clinical) moderated effect sizes; however, effects increased with the age of youth in the higher-quality studies. In terms of intervention features, mTDIs in these research studies were effective regardless of whether they included various technological features (eg, tailoring, social elements, or gamification) or support features (eg, orientation, reminders, or coaching), although the use of mTDIs in a research context likely differs in important ways from their use when taken up through self-motivation, parent direction, peer suggestion, or clinician referral. Only mTDIs with a clear prescription for frequent use (ie, at least once per week) showed significant effects, although this effect was evident only in the higher-quality subsample. Moderation analyses did not detect statistically significant differences in effect sizes based on the prescribed duration of mTDI use (weeks or sessions), and reporting issues in primary studies limited the analysis of completed duration, thereby calling for improved methodology, assessment, and reporting to clarify true effects.

CONCLUSIONS: Overall, this study’s findings demonstrate that youth can experience broad and durable benefits of mTDIs, delivered in a variety of ways, and suggest directions for future research and development of mTDIs for youth, particularly in more naturalistic and ecologically valid settings.

PMID:35904845 | DOI:10.2196/34254

Int J Oral Maxillofac Implants. 2022 Jul-Aug;37(4):784-792. doi: 10.11607/jomi.8924.

ABSTRACT

PURPOSE: Immediate dental implants revolutionized the field of implant dentistry with significant advantages over conventional implants. The lack of adequate bone in the extraction socket raises the question of the appropriate timing of implant loading. Platelet concentrates have been used widely to accelerate bone regeneration in the maxillofacial region. This study evaluates the effect of platelet concentrates on bone healing and implant stability in the maxillary and mandibular molar regions. Bone regeneration is regulated by several growth factors, particularly vascular endothelial growth factor (VEGF) and transforming growth factor-β1 (TGF-β1); therefore, quantification of these factors in platelet concentrates and its correlation with bone healing has been assessed in this study.

MATERIALS AND METHODS: The primary aim of this randomized clinical trial was to compare the stability of immediate dental implants in the maxillary and mandibular molar regions treated with platelet-rich fibrin (PRF) versus concentrated growth factors (CGF) using resonance frequency analysis (RFA). The secondary objectives were to evaluate the bone regenerate around implants with the use of PRF and CGF and to quantify growth factors VEGF and TGF-β1 in the prepared CGF and PRF and their correlation with bone healing, if any. A total of 36 patients were randomized into three groups (12 each): control, PRF, and CGF. In all patients, immediate implants were placed either with or without platelet concentrate (PRF or CGF). Implant stability was measured using RFA immediately postoperatively and at 4, 8, and 12 or 16 weeks (12 weeks for mandible and 16 weeks for maxilla) postoperatively. Radiodensity and the bone gap (horizontal/vertical) were measured on intraoral periapical radiographs immediately postoperatively and at 8 weeks and 12 or 16 weeks postoperatively.

RESULTS: On comparing the implant stability quotient (ISQ), radiodensity/grayscale (GS), and horizontal and vertical bone gap (HG and VG), there was no significant difference noted between the three groups at any point in time. On ISQ analysis at 8 weeks, the control group showed a significant improvement (P = .04), whereas at 12 or 16 weeks, significant improvement was seen in PRF (P = .03) and CGF groups (P = .02). In GS assessment, only the control group showed significant improvement at 12 or 16 weeks (P = .009). In horizontal and vertical bone gap analysis all three groups showed significant improvement at 8 weeks (control [P < .001], PRF [P = .001], CGF [P = .01]) as well as 12 or 16 weeks (control [P < .001], PRF [P < .001], CGF [P = .006]). The enzyme-linked immunosorbent assay (ELISA) quantification of VEGF and TGF-β1 showed significant concentration of VEGF in PRF as compared to the plasma, while concentration of TGF-β1 was found to be comparable in both groups.

CONCLUSION: The application of platelet concentrates seems to enhance stability of implants, but intergroup results were nonsignificant at all time points. There was no statistically significant difference between the three groups when comparing quality (radiodensity/grayscale) and quantity (horizontal and vertical gap reduction) of bone regenerate. Studies with larger sample sizes are required to make conclusive assertions regarding efficacy of platelet concentrates in dental implants.

PMID:35904836 | DOI:10.11607/jomi.8924

Int J Oral Maxillofac Implants. 2022 Jul-Aug;37(4):748-755. doi: 10.11607/jomi.8953.

ABSTRACT

PURPOSE: To evaluate the mechanical stability of highly translucent zirconia (Zr) cantilevered fixed dental prostheses (cFDPs) and to investigate the influence of the number of implants (one versus two) supporting cFDPs with different restorative materials on their mechanical stability and load-bearing capacity.

MATERIALS AND METHODS: Thirty-two specimens consisting of implant-supported prostheses embedded in resin blocks were fabricated. Sixteen specimens received one implant (bone-level implant, 4.1-mm diameter, 13-mm length; Straumann) to support two-unit cement-retained cFDPs with one extension unit and the other 16 received two implants (bone-level implant, 4.1-mm diameter, 13-mm length; Straumann) positioned corresponding to the missing maxillary central incisors to support three-unit cement-retained cFDPs with one extension unit. Two different prosthetic materials, chromium-cobalt (Cr-Co; Wirobond C+, Bego) and highly translucent Zr (Lava Plus, 3M ESPE) were selected to fabricate the two- and three-unit cFDPs. Standardized twoand three-unit Cr-Co frameworks (CC-I, n = 8; CC-II, n = 8) and highly translucent Zr frameworks (Zr-I, n = 8; Zr-II, n = 8) with a 6-mm cantilever extension were fabricated using CAD/CAM (EOS M 290). Following thermomechanical fatigue loading, the specimens were tested for fracture resistance under static loading. The influence of restoration material and number of supporting implants on fracture resistance were tested using two-way analysis of variance (ANOVA). The level of statistical significance was set below 5% (α < .05).

RESULTS: All specimens survived aging. The mean (± standard deviation) fracture resistance values were 416.25 (± 42.71) N for Zr-I, 548.75 (± 75.41) N for Zr-II, 601.0 (± 41.51) N for CC-I, and 664.5 (± 37.59) N for CC-II. CC and Zr group specimens showed significantly different fracture resistance results (P < .001). The number of implants significantly influenced the fracture resistance of Zr groups (P = .001), whereas the influence was not significant for CC groups (P = .089).

CONCLUSION: Within the limitations of this in vitro study, highly translucent zirconia cFDP frameworks demonstrated the potential to withstand reported physiologic occlusal forces applied in the anterior region. The increase in the number of implants supporting zirconia cFDPs significantly contributed to achieving higher fracture resistance values.

PMID:35904831 | DOI:10.11607/jomi.8953