Category: Nevin Manimala

J Magn Reson Imaging. 2023 Mar 17. doi: 10.1002/jmri.28682. Online ahead of print.

ABSTRACT

BACKGROUND: Schizophrenia is regarded as a brain network or connectome disorder that is associated with neurodevelopment. Children with early-onset schizophrenia (EOS) provide an opportunity to evaluate the neuropathology of schizophrenia at a very early stage without potential confounding factors. But dysfunction in brain networks of schizophrenia is inconsistent.

PURPOSE: To identify abnormal functional connectivity (FC) in EOS patients and relationships with clinical symptoms, we aimed to reveal neuroimaging phenotypes of EOS.

STUDY TYPE: Prospective, cross-sectional.

POPULATION: Twenty-six female/22 male patients (age:14.3 ± 3.45 years) with first-episode EOS, 27 female/22 male age- and gender-matched healthy controls (HC) (age:14.1 ± 4.32).

FIELD STRENGTH/SEQUENCE: 3-T, resting-state (rs) gradient-echo echo-planar imaging and three-dimensional magnetization-prepared rapid gradient-echo imaging.

ASSESSMENT: Intelligence quotient (IQ) was measured by the Wechsler Intelligence Scale-Fourth edition for Children (WISC-IV). The clinical symptoms were evaluated by the Positive and Negative Syndrome Scale (PANSS). FC strength (FCS) from rs functional MRI (rsfMRI) was used to investigate functional integrity of global brain regions. In addition, associations between regionally altered FCS and clinical symptoms in EOS patients were examined.

STATISTICAL TESTS: Two-sample t-test controlling for sample size, diagnostic method, brain volume algorithm, and age of the subjects, Bonferroni correction, Pearson’s correlation analysis. A P-value <0.05 with a minimum cluster size of 50 voxels was considered statistically significant.

RESULTS: Compared with HC, EOS patients had significantly lower total IQ scores (IQ:91.5 ± 16.1), increased FCS in the bilateral precuneus, left dorsolateral prefrontal cortex, left thalamus, and left parahippocampus (paraHIP), and decreased FCS in the right cerebellum posterior lobe and right superior temporal gyrus. The PANSS total score of EOS patients (PANSS total score:74.30 ± 7.23) was found to be positively correlated to FCS in the left paraHIP (r = 0.45).

DATA CONCLUSION: Our study revealed that disrupted FC of brain hubs illustrate multiple abnormalities in brain networks in EOS patients.

EVIDENCE LEVEL: 1 TECHNICAL EFFICACY STAGE: 2.

PMID:36932678 | DOI:10.1002/jmri.28682

Clin Trials. 2023 Mar 17:17407745231160556. doi: 10.1177/17407745231160556. Online ahead of print.

ABSTRACT

BACKGROUND: An ongoing cluster-randomized trial for the prevention of arboviral diseases utilizes covariate-constrained randomization to balance two treatment arms across four specified covariates and geographic sector. Each cluster is within a census tract of the city of Mérida, Mexico, and there were 133 eligible tracts from which to select 50. As some selected clusters may have been subsequently found unsuitable in the field, we desired a strategy to substitute new clusters while maintaining covariate balance.

METHODS: We developed an algorithm that successfully identified a subset of clusters that maximized the average minimum pairwise distance between clusters in order to reduce contamination and balanced the specified covariates both before and after substitutions were made.

SIMULATIONS: Simulations were performed to explore some limitations of this algorithm. The number of selected clusters and eligible clusters were varied along with the method of selecting the final allocation pattern.

CONCLUSION: The algorithm is presented here as a series of optional steps that can be added to the standard covariate-constrained randomization process in order to achieve spatial dispersion, cluster subsampling, and cluster substitution. Simulation results indicate that these extensions can be used without loss of statistical validity, given a sufficient number of clusters included in the trial.

PMID:36932663 | DOI:10.1177/17407745231160556

Psychogeriatrics. 2023 Mar 17. doi: 10.1111/psyg.12953. Online ahead of print.

ABSTRACT

BACKGROUND: The prevalence of anxiety and other psychological disorders has increased during the COVID-19 pandemic, especially among the elderly. Anxiety and metabolic syndrome (MetS) may aggravate each other. This study further clarified the correlation between the two.

METHODS: Adopting a convenience sampling method, this study investigated 162 elderly people over 65 years of age in Fangzhuang Community, Beijing. All participants provided baseline data on sex, age, lifestyle, and health status. The Hamilton Anxiety Scale (HAMA) was used to assess anxiety. Blood samples, abdominal circumference, and blood pressure were used to diagnose MetS. The elderly were divided into MetS and control groups according to the diagnosis of MetS. Differences in anxiety between the two groups were analysed and further stratified by age and gender. Multivariate logistic regression analysis was used to analyse the possible risk factors for MetS.

RESULTS: Compared with the control group, anxiety scores of the MetS group were statistically higher (Z = 4.78, P < 0.001). There was a significant correlation between anxiety levels and MetS (r = 0.353, P < 0.001). Multivariate logistic regression revealed that anxiety (possible anxiety vs no anxiety: odds ratio [OR] = 2.982, 95% confidence interval [CI] 1.295-6.969; definite anxiety vs no anxiety: OR = 14.573, 95%CI 3.675-57.788; P < 0.001) and BMI (OR = 1.504, 95% CI 1.275-1.774; P < 0.001) were possible risk factors for MetS.

CONCLUSION: The elderly with MetS had higher anxiety scores. Anxiety may be a potential risk factor for MetS, which provides a new perspective on anxiety and MetS.

PMID:36932654 | DOI:10.1111/psyg.12953

Am J Case Rep. 2023 Mar 18;24:e938878. doi: 10.12659/AJCR.938878.

ABSTRACT

BACKGROUND Thrombosis with thrombocytopenia syndrome (TTS), including vaccine-induced immune thrombotic thrombocytopenia (VITT), is an extremely rare adverse effect, mostly seen after initial vaccination with the viral vector-based AstraZeneca-Oxford COVID-19 vaccine. It is characterized by mild to severe thrombocytopenia and venous or arterial thrombosis. CASE REPORT Herein, we present a case of an 18-year-old male patient who developed Level 1 TTS (probable VITT) eight days after immunization with the ChADOx1 nCOV-19 vaccine (Covishield; AZ-Oxford). Initial investigations revealed severe thrombocytopenia, hemiparesis, and intracranial hemorrhage, after which the patient was treated conservatively. However, a decompressive craniotomy was performed later due to patient deterioration. One week after surgery, the patient developed bilious vomiting, lower-gastrointestinal bleeding, and abdominal distension. An abdominal CT scan was performed that showed thrombosis of the portal vein with occlusion of the left iliac vein. The patient underwent an exploratory laparotomy followed by resection and anastomosis of the small bowel due to massive gut gangrene. Due to persistent thrombocytopenia after surgery, intravenous immune globulin (IVIG) was administered. The platelet count increased thereafter, and the patient stabilized. He was discharged on the 33rd day after admission and was followed up for a year. No post-hospitalization complications were observed in the follow-up period. CONCLUSIONS Although vaccines have been proven to be highly safe and effective to end the Coronavirus Disease 2019 (COVID-19) caused pandemic, there is still a small risk of developing rare complications, including TTS and VITT. Early diagnosis and prompt intervention are key for patient management.

PMID:36932639 | DOI:10.12659/AJCR.938878

Med Sci Monit. 2023 Mar 18;29:e938566. doi: 10.12659/MSM.938566.

ABSTRACT

BACKGROUND This study evaluated the clinical efficacy of polylactic acid (PLA) membranes in guiding bone regeneration in anterior maxillary implants. MATERIAL AND METHODS Forty-eight participants with maxillary anterior tooth loss requiring implantation with guided bone regeneration were recruited and randomly divided into 2 groups (n=24): the PLA membrane (experimental) and the Bio-Gide membrane (control) group. Wound healing was observed at 1 week and 1 month postoperatively. Cone beam CT was performed immediately and at 6 and 36 months postoperatively. Soft-tissue parameters were measured at 18 and 36 months postoperatively. Implant stability quotient (ISQ) and patient satisfaction were separately evaluated at 6 and 18 months after the operation. The independent sample t test and chi-square test were preformed to analyze quantitative and descriptive statistics, respectively. RESULTS No implants were lost and there were no statistically significant differences in ISQ between the 2 groups. The labial bone plates in the experimental group exhibited a non-significantly greater extent of absorption than did the control group at 6 and 18 months postoperatively. Soft-tissue parameters did not reveal inferior results for the experimental group. Patients in both groups were satisfied. CONCLUSIONS PLA membranes are comparable to Bio-Gide in terms of the effectiveness and safety and can be used as a barrier membrane to guide bone regeneration in clinical practice.

PMID:36932638 | DOI:10.12659/MSM.938566

Phys Rev E. 2023 Feb;107(2):L022201. doi: 10.1103/PhysRevE.107.L022201.

ABSTRACT

Extreme events are unusual and rare large-amplitude fluctuations can occur unexpectedly in nonlinear dynamical systems. Events above the extreme event threshold of the probability distribution of a nonlinear process characterize extreme events. Different mechanisms for the generation of extreme events and their prediction measures have been reported in the literature. Based on the properties of extreme events, such as those that are rare in the frequency of occurrence and extreme in amplitude, various studies have shown that extreme events are both linear and nonlinear in nature. Interestingly, in this Letter, we report on a special class of extreme events which are nonchaotic and nonperiodic. These nonchaotic extreme events appear in between the quasiperiodic and chaotic dynamics of the system. We report the existence of such extreme events with various statistical measures and characterization techniques.

PMID:36932627 | DOI:10.1103/PhysRevE.107.L022201

Phys Rev E. 2023 Feb;107(2-1):024135. doi: 10.1103/PhysRevE.107.024135.

ABSTRACT

For driven open systems in contact with multiple heat reservoirs, we find the marginal distributions of work or heat do not satisfy any fluctuation theorem, but only the joint distribution of work and heat satisfies a family of fluctuation theorems. A hierarchical structure of these fluctuation theorems is discovered from microreversibility of the dynamics by adopting a step-by-step coarse-graining procedure in both classical and quantum regimes. Thus, we put all fluctuation theorems concerning work and heat into a unified framework. We also propose a general method to calculate the joint statistics of work and heat in the situation of multiple heat reservoirs via the Feynman-Kac equation. For a classical Brownian particle in contact with multiple heat reservoirs, we verify the validity of the fluctuation theorems for the joint distribution of work and heat.

PMID:36932622 | DOI:10.1103/PhysRevE.107.024135

Phys Rev E. 2023 Feb;107(2-1):024210. doi: 10.1103/PhysRevE.107.024210.

ABSTRACT

We consider a quantum many-body system-the Bose-Hubbard system on three sites-which has a classical limit, and which is neither strongly chaotic nor integrable but rather shows a mixture of the two types of behavior. We compare quantum measures of chaos (eigenvalue statistics and eigenvector structure) in the quantum system, with classical measures of chaos (Lyapunov exponents) in the corresponding classical system. As a function of energy and interaction strength, we demonstrate a strong overall correspondence between the two cases. In contrast to both strongly chaotic and integrable systems, the largest Lyapunov exponent is shown to be a multivalued function of energy.

PMID:36932617 | DOI:10.1103/PhysRevE.107.024210

Phys Rev E. 2023 Feb;107(2-1):024603. doi: 10.1103/PhysRevE.107.024603.

ABSTRACT

This study aims to examine experimental conditions in which active particles are forced by their surroundings to move forward and backward in a continuous oscillatory manner. The experimental design is based on using a vibrating self-propelled toyrobot called hexbug, which is placed inside a narrow channel closed on one end by a rigid moving wall. Using the end-wall velocity as a controlling factor, the main forward mode of the hexbug movement can be turned to mostly rearward mode. We investigate the bouncing hexbug motion on both experimental and theoretical grounds. The Brownian model of active particles with inertia is employed in the theoretical framework. The model itself uses a pulsed Langevin equation in order to simulate abrupt changes in velocity that mimic hexbug propulsion in the moments when its legs make contact with the base plate. Significant directional asymmetry is caused by the legs bending backward. We demonstrate that the simulation successfully reproduces the experimental characteristics of hexbug motion after regressing the spatial and temporal statistical characteristics, especially when directional asymmetry is under consideration.

PMID:36932604 | DOI:10.1103/PhysRevE.107.024603

Phys Rev E. 2023 Feb;107(2-2):025103. doi: 10.1103/PhysRevE.107.025103.

ABSTRACT

A three-dimensional blunt-base bluff body in a uniform flow is subjected to long-time stochastic dynamics of switching between two opposite wake states. This dynamic is investigated experimentally within the Reynolds number range Re ≃10^{4}-10^{5}. Long-time statistics coupled to a sensitivity analysis to the body attitude (defined as the pitch angle of the body with respect to the incoming flow) show that the wake switching rate decreases as Re increases. Equipping the body with passive roughness elements (turbulators) modifies the boundary layers before separation, seen as the inlet condition for the wake dynamic. Depending on their location and Re, the viscous sublayer length scale and the turbulent layer thickness can be modified independently. This sensitivity analysis to the inlet condition shows that a decrease of the viscous sublayer length scale at a given turbulent layer thickness leads to a decrease in the switching rate, whereas the modification of the turbulent layer thickness has almost no effect on the switching rate.

PMID:36932601 | DOI:10.1103/PhysRevE.107.025103