Obsessive-compulsive disorder (OCD) is associated with increased electroencephalographic (EEG) delta and theta oscillatory power but reduced delta connectivity.

Obsessive-Compulsive Disorder (OCD) is a mental health condition causing significant decline in the quality of life of sufferers and the limited knowledge on the pathophysiology hinders successful treatment. The aim of the current study was to examine electroencephalographic (EEG) findings of OCD to broaden our understanding of the disease. Resting-state eyes-closed EEG data was recorded from 25 individuals with OCD and 27 healthy controls (HC). The 1/f arrhythmic activity was removed prior to computing oscillatory powers of all frequency bands (delta, theta, alpha, beta, gamma). Cluster-based permutation was used for between-group statistical analyses, and comparisons were performed for the 1/f slope and intercept parameters. Functional connectivity (FC) was measured using coherence and debiased weighted phase lag index (d-wPLI), and statistically analyzed using the Network Based Statistic method. Compared to HC, the OCD group showed increased oscillatory power in the delta and theta bands in the fronto-temporal and parietal brain regions. However, there were no significant between-group findings in other bands or 1/f parameters. The coherence measure showed significantly reduced FC in the delta band in OCD compared to HC but the d-wPLI analysis showed no significant differences. OCD is associated with raised oscillatory power in slow frequency bands in the fronto-temporal brain regions, which agrees with the previous literature and therefore is a potential biomarker. Although delta coherence was found to be lower in OCD, due to inconsistencies found between measures and the previous literature, further research is required to ascertain definitive conclusions.

Obsessive-compulsive disorder (OCD) is associated with increased engagement of frontal brain regions across multiple event-related potentials.

BACKGROUND: Obsessive-compulsive disorder (OCD) is a psychiatric condition leading to significant distress and poor quality of life. Successful treatment of OCD is restricted by the limited knowledge about its pathophysiology. This study aimed to investigate the pathophysiology of OCD using electroencephalographic (EEG) event-related potentials (ERPs), elicited from multiple tasks to characterise disorder-related differences in underlying brain activity across multiple neural processes. METHODS: ERP data were obtained from 25 OCD patients and 27 age- and sex-matched healthy controls (HCs) by recording EEG during flanker and go/nogo tasks. Error-related negativity (ERN) was elicited by the flanker task, while N200 and P300 were generated using the go/nogo task. Primary comparisons of the neural response amplitudes and the topographical distribution of neural activity were conducted using scalp field differences across all time points and electrodes. RESULTS: Compared to HCs, the OCD group showed altered ERP distributions. Contrasting with the previous literature on ERN and N200 topographies in OCD where fronto-central negative voltages were reported, we detected positive voltages. Additionally, the P300 was found to be less negative in the frontal regions. None of these ERP findings were associated with OCD symptom severity. CONCLUSIONS: These results indicate that individuals with OCD show altered frontal neural activity across multiple executive function-related processes, supporting the frontal dysfunction theory of OCD. Furthermore, due to the lack of association between altered ERPs and OCD symptom severity, they may be considered potential candidate endophenotypes for OCD.

Thermoresponsive chiral plasmonic nanoparticles.

Chiral metallic nanoparticles can exhibit novel plasmonic circular dichroism (PCD) in the ultraviolet and visible range of the electromagnetic spectrum. Here, we investigate how thermoresponsive dielectric nanoenvironments will influence such PCD responses through poly(N-isopropylacrylamide) (PNIPAM) modified chiral gold nanorods (AuNRs). We observed the temperature-dependent chiral plasmonic responses distinctly from unmodified counterparts. As for the modified systems, the PCD peaks for both L-AuNRs and D-AuNRs at 50 °C red shifted simultaneously with enhanced intensities compared to the results at 20 °C. In contrast, the unmodified L-AuNRs and D-AuNRs exhibited no peak shift with reduced intensities. Subsequent simulation and experimental studies demonstrated that the enhanced PCD was attributed to PNIPAM chain collapse causing the increase of the refractive index by expelling minute water out of the corona surrounding chiral plasmonic AuNRs. Notably, such thermoresponsive chiral plasmonic responses are reversible, general, and extendable to other types of chiral plasmonic nanoparticles.

Genome-wide association, prediction and heritability in bacteria with application to Streptococcus pneumoniae.

Whole-genome sequencing has facilitated genome-wide analyses of association, prediction and heritability in many organisms. However, such analyses in bacteria are still in their infancy, being limited by difficulties including genome plasticity and strong population structure. Here we propose a suite of methods including linear mixed models, elastic net and LD-score regression, adapted to bacterial traits using innovations such as frequency-based allele coding, both insertion/deletion and nucleotide testing and heritability partitioning. We compare and validate our methods against the current state-of-art using simulations, and analyse three phenotypes of the major human pathogen Streptococcus pneumoniae, including the first analyses of minimum inhibitory concentrations (MIC) for penicillin and ceftriaxone. We show that the MIC traits are highly heritable with high prediction accuracy, explained by many genetic associations under good population structure control. In ceftriaxone MIC, this is surprising because none of the isolates are resistant as per the inhibition zone criteria. We estimate that half of the heritability of penicillin MIC is explained by a known drug-resistance region, which also contributes a quarter of the ceftriaxone MIC heritability. For the within-host carriage duration phenotype, no associations were observed, but the moderate heritability and prediction accuracy indicate a moderately polygenic trait.

Chiral Plasmonic Ellipsoids: An Extended Mie-Gans Model.

Mie-Gans theory optically characterizes ellipsoidal and by extension generally elongated nonchiral metal nanoparticles (MNPs) and is ubiquitous in verifying experimental results and predicting particle behavior. Recently, elongated chiral MNPs have garnered enthusiasm, but a theory to characterize their chiroptical behavior is lacking in the literature. In this Letter, we present an ab initio model for chiral ellipsoidal MNPs to address this shortcoming and demonstrate that it reduces to the general Mie-Gans model under nonchiral conditions, produces results that concur with state-of-the-art numerical simulations, and can accurately replicate recent experimental measurements. Furthermore, to gain physical insights, we analyze factors such as background medium permittivity and particle size that drive the chiroptical activity using two types of plasmonic chiral MNPs. We also demonstrate the utility of our model in metamaterial design. Generic features of our model can be extended to characterize similar elongated chiral MNPs, fueling many other variants of the current model.

Repetitive Transcranial Magnetic Stimulation for Obsessive-Compulsive Disorder: A Meta-analysis of Randomized, Sham-Controlled Trials.

BACKGROUND: Obsessive-compulsive disorder (OCD) is a chronic, disabling mental health condition with limited treatment options available to date. Numerous randomized controlled trials have explored the efficacy of repetitive transcranial magnetic stimulation (rTMS) in OCD. This meta-analysis synthesized data from selected randomized controlled trials and examined the impact of different treatment parameters to generate hypotheses that would direct future randomized controlled trials. METHODS: A database search was performed to identify studies published in English up to October 2020. Randomized, sham-controlled studies that used rTMS to treat OCD were included. Effect sizes were calculated using Hedges' g for pre- to post-treatment Yale-Brown Obsessive Compulsive Scale scores. Subgroup analyses were conducted to assess the effects of variations in rTMS treatment parameters. RESULTS: A total of 26 studies with 781 participants were included. Overall, rTMS demonstrated a modest effect on reduction of Yale-Brown Obsessive Compulsive Scale scores (Hedges' g = 0.64, 95% confidence interval = 0.39-0.89; p < .0001). The largest significant effect size was obtained by targeting the bilateral dorsolateral prefrontal cortex. High- and low-frequency rTMS showed comparable effects. Studies with follow-up data suggested that the effects of active rTMS remain significantly superior to those of sham 4 weeks after treatment. CONCLUSIONS: The therapeutic effects of rTMS are superior to those of sham in the treatment of OCD. Targeting the bilateral dorsolateral prefrontal cortex was the most favorable approach in administering rTMS. Further research is required to determine the optimal frequency, total pulses per session, and duration of treatment with rTMS for OCD.

Machine learning based temperature prediction of poly(N-isopropylacrylamide)-capped plasmonic nanoparticle solutions.

The temperature-dependent optical properties of gold nanoparticles that are capped with the thermo-sensitive polymer: 'poly(N-isopropylacrylamide)' (PNIPAM), have been studied extensively for several years. Also, their suitability to function as nanoscopic thermometers for bio-sensing applications has been suggested numerous times. In an attempt to establish this, many have studied the temperature-dependent optical resonance characteristics of these particles; however, developing a simple mathematical relationship between the optical measurements and the solution temperature remains an open challenge. In this paper, we attempt to systematically address this problem using machine learning techniques to quickly and accurately predict the solution-temperature, based on spectroscopic data. Our emphasis is on establishing a simple and practically useful solution to this problem. Our dataset comprises spectroscopic absorption data from both nanorods and nanobipyramids capped with PNIPAM, measured at discretely varied and pre-set temperature states. Specific regions of the spectroscopic data are selected as features for prediction using random forest (RF), gradient boosting (GB) and adaptive boosting (AB) regression techniques. Our prediction results indicate that RF and GB techniques can be used successfully to predict solution temperatures instantly to within 1 °C of accuracy.

Scattering characteristics of an exciton-plasmon nanohybrid made by coupling a monolayer graphene nanoflake to a carbon nanotube.

A hybrid nanostructure where a graphene nanoflake (GNF) is optically coupled to a carbon nanotube (CNT) could potentially possess enhanced sensing capabilities compared to the individual constituents whilst inheriting their high biocompatibility, favourable electrical, mechanical and spectroscopic properties. Therefore, in this paper, we investigate the scattering characteristics of an all-carbon exciton-plasmon nanohybrid which was made by coupling an elliptical GNF resonator to a semiconducting CNT gain element. We analytically model the nanohybrid as an open quantum system using cavity quantum electrodynamics. We derive analytical expressions for the dipole moment operator and the dipole response field of the GNF and characterize the Rayleigh scattering spectrum of the nanohybrid. These analytical expressions are valid for any arbitrary ellipsoidal nanoresonator coupled to a quantum emitter. Furthermore, we perform a detailed numerical analysis, the results of which indicate that the GNF-CNT nanohybrid exhibits enhanced and versatile scattering capabilities compared to the individual constituents. We show that the spectral signatures of the nanohybrid are highly tunable using a multitude of system parameters such as Fermi energy of the GNF, component dimensions, GNF-CNT separation distance and the permittivity of the submerging medium. We finally demonstrate the prospect of using the proposed nanohybrid to reconstruct the permittivity profile of a tumour. The high biocompatibility and high sensitivity to the dielectric properties of the environment make the proposed GNF-CNT nanohybrid an ideal candidate for such biosensing applications.

Optoelectronic figure of merit of a metal nanoparticle-quantum dot (MNP-QD) hybrid molecule for assessing its suitability for sensing applications.

Recently, many have studied various configurations of metal nanoparticle-quantum dot (MNP-QD) hybrid molecules based on different metals and tunable parameters. In this paper, we aim to incite the interest in using MNP-QD nanohybrids, which possess sensing capabilities superior to those of the individual constituents, for sensing applications that rely on scattered light. When assessing whether a given MNP-QD configuration is suited for an application, sometimes it is hard to assess the pros and cons of a given configuration against other candidates. Here we propose a simple, elegant relative figure of merit (RFoM), which focuses on maximizing the scattered intensity and the refractive index sensitivity of the nanohybrid, to rank the suitability of viable MNP-QD configurations for a particular sensing application. We use the proposed RFoM to analyse the optical spectra of noble, transition, post transition and alkali metal based MNP-QD nanohybrids using the representative metals Au, Ag, Cu, Al and Na, adopting a generalized nonlocal optical response (GNOR) method based cavity QED approach. Based on our observations, we suggest how the usage of MNP-QD nanohybrids could improve the conventionally studied tumour targeting applications. Moreover, we propose potential substitutes for noble metals conventionally considered for MNP-QD nanohybrids.

Relationship between acne vulgaris and cosmetic usage in Sri Lankan urban adolescent females.

BACKGROUND: Acne vulgaris is one of the commonest skin disorders affecting up to 80% of the world population at least during adolescence. Significant psychosocial effects such as depression and poor personality development have been linked with acne, especially in female adolescents. Various causative factors, including cosmetic exposure, have been attributed toward acne. OBJECTIVE: To analyze the association between frequent exposure to cosmetics and severity of acne in adolescent females. METHOD: A cross-sectional analytical study was performed on 140 girls from three schools in Colombo, Sri Lanka. A self-administered questionnaire was utilized to assess the patterns of cosmetic usage. Grading acne of the participants was performed by the researchers utilizing a standard acne grading scale. RESULTS: The overall prevalence of acne in our study population was 91.4% with a mean acne grade of 3.09. At least one cosmetic type was used by 126 (90%) of the population. A Pearson correlation coefficient (r) value of .452 (P < .001) was obtained between cosmetic exposure and acne grade, which indicates a statistically significant correlation. A chi-square value of 22.875 was obtained at a degree of freedom of 2 (P < .001), enabling us to reject the null hypothesis that there is no significant association between cosmetic usage and acne severity. CONCLUSION: Our results convey a significant positive association between frequent exposure to cosmetics and severity of acne in adolescent females. Girls of this age group must be made aware that cosmetic usage may be a potential aggravating factor for their facial acne.

Morphological variations of the human ejaculatory ducts in relation to the prostatic urethra.

Loss of ejaculation can follow transurethral resection of the prostate (TURP). Periverumontanal prostate tissue is preserved in ejaculation-preserving TURP (ep-TURP). Knowledge of ejaculatory duct anatomy in relation to the prostatic urethra can help in ep-TURP. This was evaluated in cross-sections of the prostate using a 3 D model to determine a safe zone for resecting the prostate in ep-TURP. A 3 D reconstruction of the ejaculatory ducts was developed on the basis of six prostate gland cross-sections. The measurements obtained from the 3 D model were standardized according to the maximum width of the prostate. Simple linear regressions were used to predict the relationships of the ejaculatory ducts. The maximum widths of the prostates ranged from 22.60 to 52.10 mm. The ejaculatory ducts entered the prostate with a concavity directed posterolaterally. They then proceeded toward the seminal colliculus in a fairly straight course, and from that point they angulated anteromedially. As they opened into the prostatic urethra they diverged. Significant regression models predicted the relationships of the ejaculatory ducts to the prostatic urethra based on the sizes of the prostates. The 3 D anatomy of ejaculatory ducts can be predicted on the basis of prostate width. The ejaculatory ducts can be preserved with 95% accuracy if a block of tissue 7.5 mm from the midline on either side of the seminal colliculus is preserved, up to 10 mm proximal to the level of the seminal colliculus, during TURP. Clin. Anat. 31:456-461, 2018. © 2017 Wiley Periodicals, Inc.