Category: Nevin Manimala

Phys Rev Lett. 2024 Mar 22;132(12):127101. doi: 10.1103/PhysRevLett.132.127101.

ABSTRACT

Very recently, a fundamental observable has been introduced and analyzed to quantify the exploration of random walks: the time τ_{k} required for a random walk to find a site that it never visited previously, when the walk has already visited k distinct sites. Here, we tackle the natural issue of the statistics of M_{n}, the longest duration out of τ_{0},…,τ_{n-1}. This problem belongs to the active field of extreme value statistics, with the difficulty that the random variables τ_{k} are both correlated and nonidentically distributed. Beyond this fundamental aspect, we show that the asymptotic determination of the statistics of M_{n} finds explicit applications in foraging theory and allows us to solve the open d-dimensional starving random walk problem, in which each site of a lattice initially contains one food unit, consumed upon visit by the random walker, which can travel S steps without food before starving. Processes of diverse nature, including regular diffusion, anomalous diffusion, and diffusion in disordered media and fractals, share common properties within the same universality classes.

PMID:38579219 | DOI:10.1103/PhysRevLett.132.127101

J Clin Psychol. 2024 Apr 5. doi: 10.1002/jclp.23689. Online ahead of print.

ABSTRACT

BACKGROUND: Despite the pervasiveness of patient-reported emptiness and the high burden it carries, emptiness is poorly understood. In the current study, we used a general inductive approach to examine experiences with emptiness in a diagnostically diverse sample of treatment-seeking patients with severe and acute psychopathology. As a secondary aim, we also examined whether identified themes differed among patients with a primary diagnosis of borderline personality disorder or major depressive disorder.

METHOD: Participants (n = 150) ranged from 18 to 69 years old (M = 33.15, SD = 12.41; 79.3% non-Hispanic White; 57.3% females). All patients completed the borderline personality disorder module of the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Personality Disorders and the Mini International Neuropsychiatric Interview. Interviewers documented patients’ responses to follow-up questions. Patients were included in the study if they endorsed chronic feelings of emptiness and elaborations were documented.

RESULTS: We identified 10 themes associated with patient-reported emptiness: (1) purposeless, (2) lack of connection, (3) numbness, (4) self-deprecation, (5) lack of identity, (6) lack of motivation, (7) hopelessness, (8) lack of pleasure, (9) physical sensation, and (10) dissociation. Themes were consistent across diagnostic status, with one exception: patients with borderline personality disorder were more likely to report that emptiness was associated with dissociation relative to patients with major depressive disorder.

CONCLUSION: Our results suggest that emptiness may reflect a multifaceted and transdiagnostic construct. Identified themes may help to support the assessment of emptiness and can be used to guide individualized treatments.

PMID:38579178 | DOI:10.1002/jclp.23689

Prosthet Orthot Int. 2024 Apr 5. doi: 10.1097/PXR.0000000000000337. Online ahead of print.

ABSTRACT

BACKGROUND: In children with unilateral spastic cerebral palsy (USCP), ankle-foot orthoses (AFOs) are widely used to correct common gait deviations such as a drop-foot pattern. Most studies on this topic have investigated specific time points while omitting other parts of the gait cycle.

OBJECTIVES: This study investigated the separate effects of prefabricated carbon fiber AFOs and custom-made hinged AFOs compared with barefoot walking in children with USCP with a drop-foot gait pattern using statistical parametric mapping.

STUDY DESIGN: Retrospective, cross-sectional, repeated measures study.

METHODS: Twenty ambulatory children (9.9 ± 2.5 years) with USCP and a drop-foot gait pattern were included. Kinematics, kinetics, and spatiotemporal parameters assessed during 3-dimensional gait analysis were compared between barefoot and AFO walking. Statistical parametric mapping was used to compare joint angles and moment waveforms. Kinematics, kinetics and spatiotemporal parameters assessed during 3-dimensional gait analysis were compared between barefoot and AFO walking for each AFO type but not between the 2 AFO types.

RESULTS: Compared with barefoot walking, there was a steeper sole angle at initial contact, corresponding to a heel strike pattern, and an increased ankle dorsiflexion in swing with the use of both AFOs. The ankle plantar flexion moment during loading response increased. Ankle power generation during pre-swing decreased in the carbon fiber AFO group when walking with AFOs.

CONCLUSIONS: Both AFOs were beneficial for improving a drop-foot gait pattern in these small patient groups and can, therefore, be recommended to treat this gait deviation in patients with unilateral cerebral palsy. However, the reduction in ankle power generation during push-off and additional goals targeted by AFOs, such as correction of structural or flexible foot deformities, should be considered for prescription.

PMID:38579167 | DOI:10.1097/PXR.0000000000000337

ACS Synth Biol. 2024 Apr 5. doi: 10.1021/acssynbio.3c00662. Online ahead of print.

ABSTRACT

This paper presents Maud, a command-line application that implements Bayesian statistical inference for kinetic models of biochemical metabolic reaction networks. Maud takes into account quantitative information from omics experiments and background knowledge as well as structural information about kinetic mechanisms, regulatory interactions, and enzyme knockouts. Our paper reviews the existing options in this area, presents a case study illustrating how Maud can be used to analyze a metabolic network, and explains the biological, statistical, and computational design decisions underpinning Maud.

PMID:38579163 | DOI:10.1021/acssynbio.3c00662

Chaos. 2024 Apr 1;34(4):043125. doi: 10.1063/5.0199364.

ABSTRACT

Two well-known facets in protein synthesis in eukaryotic cells are transcription of DNA to pre-RNA in the nucleus and the translation of messenger-RNA (mRNA) to proteins in the cytoplasm. A critical intermediate step is the removal of segments (introns) containing ∼97% of the nucleic-acid sites in pre-RNA and sequential alignment of the retained segments (exons) to form mRNA through a process referred to as splicing. Alternative forms of splicing enrich the proteome while abnormal splicing can enhance the likelihood of a cell developing cancer or other diseases. Mechanisms for splicing and origins of splicing errors are only partially deciphered. Our goal is to determine if rules on splicing can be inferred from data analytics on nucleic-acid sequences. Toward that end, we represent a nucleic-acid site as a point in a plane defined in terms of the anterior and posterior sub-sequences of the site. The “point-set” representation expands analytical approaches, including the use of statistical tools, to characterize genome sequences. It is found that point-sets for exons and introns are visually different, and that the differences can be quantified using a family of generalized moments. We design a machine-learning algorithm that can recognize individual exons or introns with 91% accuracy. Point-set distributions and generalized moments are found to differ between organisms.

PMID:38579148 | DOI:10.1063/5.0199364

Ann Hepatol. 2024 Mar-Apr;29(2):101174. doi: 10.1016/j.aohep.2023.101174. Epub 2023 Oct 29.

ABSTRACT

INTRODUCTION AND OBJECTIVES: Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease with a high prevalence worldwide and poses serious harm to human health. There is growing evidence suggesting that the administration of specific supplements or nutrients may slow NAFLD progression. Silymarin is a hepatoprotective extract of milk thistle, but its efficacy in NAFLD remains unclear.

MATERIALS AND METHODS: Relevant studies were searched in PubMed, Embase, the Cochrane Library, Web of Science, clinicaltrails.gov, and China National Knowledge Infrastructure and were screened according to the eligibility criteria. Data were analyzed using Revman 5.3. Continuous values and dichotomous values were pooled using the standard mean difference (SMD) and odds ratio (OR). Heterogeneity was evaluated using the Cochran’s Q test (I² statistic). A P<0.05 was considered statistically significant.

RESULTS: A total of 26 randomized controlled trials involving 2,375 patients were included in this study. Administration of silymarin significantly reduced the levels of TC (SMD[95%CI]=-0.85[-1.23, -0.47]), TG (SMD[95%CI]=-0.62[-1.14, -0.10]), LDL-C (SMD[95%CI]=-0.81[-1.31, -0.31]), FI (SMD[95%CI]=-0.59[-0.91, -0.28]) and HOMA-IR (SMD[95%CI]=-0.37[-0.77, 0.04]), and increased the level of HDL-C (SMD[95%CI]=0.46[0.03, 0.89]). In addition, silymarin attenuated liver injury as indicated by the decreased levels of ALT (SMD[95%CI]=-12.39[-19.69, -5.08]) and AST (SMD[95% CI]=-10.97[-15.51, -6.43]). The levels of fatty liver index (SMD[95%CI]=-6.64[-10.59, -2.69]) and fatty liver score (SMD[95%CI]=-0.51[-0.69, -0.33]) were also decreased. Liver histology of the intervention group revealed significantly improved hepatic steatosis (OR[95%CI]=3.25[1.80, 5.87]).

CONCLUSIONS: Silymarin can regulate energy metabolism, attenuate liver damage, and improve liver histology in NAFLD patients. However, the effects of silymarin will need to be confirmed by further research.

PMID:38579127 | DOI:10.1016/j.aohep.2023.101174

J Phys Chem B. 2024 Apr 5. doi: 10.1021/acs.jpcb.3c07447. Online ahead of print.

ABSTRACT

We critically assess the capabilities of classical density functional theory (DFT) based on the perturbed-chain statistical associating fluid theory (PC-SAFT) equation of state to predict the solvation free energies of small molecules in various hydrocarbon solvents. We compare DFT results with experimental data from the Minnesota solvation database and utilize statistical methods to analyze the accuracy of our approach, as well as its weaknesses. The mean absolute error of the solvation free energies is 3.7 kJ mol^-1 for n-alkane solvents, ranging from pentane to hexadecane, with 473 solute-solvent systems. For solvents consisting of cyclic hydrocarbons (cyclohexane, benzene, toluene, and ethylbenzene) with 245 solute-solvent systems, we report a slightly larger mean absolute error of 4.2 kJ mol^-1. We identify three possible sources of errors: (i) the neglect of solute-solvent and solvent-solvent Coulomb interactions, which limits the applicability of PC-SAFT DFT to nonpolar and weakly polar molecules; (ii) the solute’s Lennard-Jones parameters supplied by the general AMBER force field, which are not parametrized toward solvation free energies; and (iii) the application of the Lorentz-Berthelot combining rules to the dispersive interactions between a segment of the PC-SAFT solvent and a Lennard-Jones interaction site of the solute. The approach is more accurate than standard implementations of phenomenological models in common chemistry software packages, which exhibit mean absolute errors larger than 9.12 kJ mol^-1, even though newer phenomenological models achieve a mean absolute error of about 2 kJ mol^-1. PC-SAFT DFT is more computationally efficient than state of the art explicit molecular simulations in combination with free energy perturbation methods. It is predictive with respect to solvation free energies, i.e., the input for the model is the (element-specific) molecular force field, the solute configuration from molecular dynamics simulations, and the (substance-specific) PC-SAFT parameters. The PC-SAFT parametrization uses pure-component data and does not require experimental solvation free energies. The PC-SAFT equation of state, without applying a DFT formalism, can also be used to calculate solvation free energies, provided that the PC-SAFT parameters for the solute are available. A large number of substances was recently parametrized by members of our group (Esper, T.; Bauer, G.; Rehner, P.; Gross, J. Ind. Eng. Chem. Res. 2023, 62), which enables a comparison to the DFT approach for 103 substances. Accurate results are obtained from the PC-SAFT equation of state with an MAE below 2.51 kJ mol^-1. The DFT approach does not require PC-SAFT parameters for the solute and can be applied to all solutes that can be represented by the molecular force field.

PMID:38579126 | DOI:10.1021/acs.jpcb.3c07447

J Oral Implantol. 2024 Feb 1;50(1):31-38. doi: 10.1563/aaid-joi-D-23-00033.

ABSTRACT

The aim of this study was to evaluate the mechanical behavior of UCLA and Mini-conical abutments for implants with Tri-channel connections regarding torque loss and vertical misfit. Twenty 3-element metal-ceramic fixed partial dentures (FPD) supported by 2 implants were manufactured and divided into 2 groups (n = 10): UCLA (group 1) and Mini-conical Abutments (group 2). The evaluation of torque loss was carried out before and after mechanical cycling, while the vertical fit was evaluated throughout the different stages of manufacturing the prostheses, as well pre- and postcycling (300,000 cycles, 30 N). Statistical analyses of torque loss and vertical misfit were performed using the linear mixed effects model. Both groups showed torque loss after mechanical cycling (P < .05); however, there was no significant percentage differences between them (P = .795). Before cycling, the groups showed a significant difference in terms of vertical misfit values (P < .05); however, this difference was no long observed after cycling (P = .894). Both groups showed torque loss after the cycling test, with no significant difference (P > .05). There was no significant difference in vertical misfit after mechanical cycling; however, in group 1 (UCLA) there was accommodation of the implant-UCLA abutment interface, while group 2 (Mini-conical abutment) did not show changes in the interface with the implant after the test. Both groups behaved similarly regarding the torque loss of the prosthesis retention screws pre- and postmechanical cycling, with greater loss after the test.

PMID:38579114 | DOI:10.1563/aaid-joi-D-23-00033

J Oral Implantol. 2024 Feb 1;50(1):45-49. doi: 10.1563/aaid-joi-D-23-00072.

ABSTRACT

The stability of implant-abutment joint is fundamental for the long-term success of implant rehabilitation. The screw loosening, fracture, and head deformation are among the most common mechanical complications. Several surface treatments of titanium screws have been proposed to improve their resistance and stability. Diamond-like carbon (DLC) coating of the materials is widely used to increase their wear resistance and durability. The present study aimed to evaluate the effect of carbon fiber coating on the screw head on screw removal torque and screw head stripping. One hundred titanium implant screws were used, 50 without coating (Group 1) and 50 with DLC coating of the screw head (Group 2). Each screw was tightened with a torque of 25 Ncm and unscrewed 10 times. The removal torque was measured with a digital cap torque tester for each loosening. Optical 3d measurement of the screw head surface was performed by a fully automatic machine before and after multiple tightening to investigate surface modifications. The reverse torque values decreased with repeated tightening and loosening cycles in both groups without significant differences (P > .05). Optical measurements of surface dimensions revealed average changes of 0.0357 mm in Group 1 and 0.02312 mm in Group 2, which resulted to be statistically significant (P < .001). The DLC coating of the retention screw head can prevent its distortion and wear, especially after multiple tightening.

PMID:38579112 | DOI:10.1563/aaid-joi-D-23-00072

JMIR Mhealth Uhealth. 2024 Apr 5;12:e53006. doi: 10.2196/53006.

ABSTRACT

BACKGROUND: The effectiveness of timely medication, physical activity (PA), a healthy diet, and blood pressure (BP) monitoring for promoting health outcomes and behavioral changes among patients with hypertension is supported by a substantial amount of literature, with “adherence” playing a pivotal role. Nevertheless, there is a lack of consistent evidence regarding whether digital interventions can improve adherence to healthy behaviors among individuals with hypertension.

OBJECTIVE: The aim was to develop a health behavioral digital intervention for hypertensive patients (HBDIHP) based on an intelligent health promotion system and WeChat following the behavior change wheel (BCW) theory and digital micro-intervention care (DMIC) model and assess its efficacy in controlling BP and improving healthy behavior adherence.

METHODS: A 2-arm, randomized trial design was used. We randomly assigned 68 individuals aged >60 years with hypertension in a 1:1 ratio to either the control or experimental group. The digital intervention was established through the following steps: (1) developing digital health education materials focused on adherence to exercise prescriptions, Dietary Approaches to Stop Hypertension (DASH), prescribed medication, and monitoring of BP; (2) using the BCW theory to select behavior change techniques; (3) constructing the intervention’s logic following the guidelines of the DMIC model; (4) creating an intervention manual including the aforementioned elements. Prior to the experiment, participants underwent physical examinations at the community health service center’s intelligent health cabin and received intelligent personalized health recommendations. The experimental group underwent a 12-week behavior intervention via WeChat, while the control group received routine health education and a self-management manual. The primary outcomes included BP and adherence indicators. Data analysis was performed using SPSS, with independent sample t tests, chi-square tests, paired t tests, and McNemar tests. A P value <.05 was considered statistically significant.

RESULTS: The final analysis included 54 participants with a mean age of 67.24 (SD 4.19) years (n=23 experimental group, n=31 control group). The experimental group had improvements in systolic BP (-7.36 mm Hg, P=.002), exercise time (856.35 metabolic equivalent [MET]-min/week, P<.001), medication adherence (0.56, P=.001), BP monitoring frequency (P=.02), and learning performance (3.23, P<.001). Both groups experienced weight reduction (experimental: 1.2 kg, P=.002; control: 1.11 kg, P=.009) after the intervention. The diet types and quantities for both groups (P<.001) as well as the subendocardial viability ratio (0.16, P=.01) showed significant improvement. However, there were no statistically significant changes in other health outcomes.

CONCLUSIONS: The observations suggest our program may have enhanced specific health outcomes and adherence to health behaviors in older adults with hypertension. However, a longer-term, larger-scale trial is necessary to validate the effectiveness.

TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2200062643; https://www.chictr.org.cn/showprojEN.html?proj=172782.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.2196/46883.

PMID:38578692 | DOI:10.2196/53006