Impact of segmented optical axial length on the performance of intraocular lens power calculation formulas.

PURPOSE: To investigate the difference between the segmented axial length (AL) and the composite AL on a swept-source optical coherence tomography biometer and to evaluate the subsequent effects on artificial intelligence intraocular lens (IOL) power calculations: the Kane and Hill-RBF 3.0 formulas compared with established vergence formulas. SETTING: National Hospital Organization, Tokyo Medical Center, Japan. DESIGN: Retrospective case series. METHODS: Consecutive patients undergoing cataract surgery with a single-piece IOL were reviewed. The prediction accuracy of the Barrett Universal II, Haigis, Hill-RBF 3.0, Hoffer Q, Holladay 1, Kane, and SRK/T formulas based on 2 ALs were compared for each formula. The heteroscedastic test was used with the SD of prediction errors as the endpoint for formula performance. RESULTS: The study included 145 eyes of 145 patients. The segmented AL (24.83 ± 1.89) was significantly shorter than the composite AL (24.88 ± 1.96, P < .001). Bland-Altman analysis revealed a negative proportional bias for the differences between the segmented AL and the composite AL. The SD values obtained by Hoffer Q, Holladay 1, and SRK/T formulas based on the segmented AL (0.52 diopters [D], 0.54 D, and 0.50 D, respectively) were significantly lower than those based on the composite AL (0.57 D, 0.60 D, and 0.52 D, respectively, P < .01). CONCLUSIONS: The segmented ALs were longer in short eyes and shorter in long eyes than the composite ALs. The refractive accuracy can be improved in the Hoffer Q, Holladay 1, and SRK/T formulas by changing the composite ALs to the segmented ALs.

In vitro anti-severe acute respiratory syndrome coronavirus 2 effect of Ephedra przewalskii Stapf extract.

ETHNOPHARMACOLOGICAL RELEVANCE: The terrestrial stems of Ephedra (Ephedra spp.; including Ephedra sinica Stapf and Ephedra przewalskii Stapf) extracts are used in traditional medicines in East Asia. In Japan, the Kampo formula containing E. sinica extract is prescribed for the treatment of the common cold, influenza virus infections, and mild symptoms of coronavirus disease 2019 (COVID-19). Although ephedrine alkaloids in E. sinica exert antitussive effects, they may have side effects associated with the sympathetic nervous system. E. przewalskii extract, a drug used in traditional Uyghur and Mongolian medicine, is considered to be free of ephedrine alkaloids and is a promising candidate for the treatment of infectious diseases. However, its use is currently limited because evidence of its antiviral efficacy remains inconclusive. AIM OF THE STUDY: We compared the anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) effects of E. przewalskii and E. sinica extracts in vitro. Additionally, we examined the differences in their antiviral effects against different SARS-CoV-2 strains. MATERIALS AND METHODS: VeroE6/TMPRSS2 cells were infected with SARS-CoV-2 (Conventional, Delta, and Omicron strains-BA.1, BA.2, BA.4, and BA.5), and lysates prepared from each herbal extract were added. The infectious titer was determined using the 50% tissue culture infectious dose (TCID50) method; in turn, the half-maximal inhibitory concentration (IC50) was calculated for each extract to compare the antiviral efficacy of E. sinica and E. przewalskii extracts. Further, the extracts were compared with remdesivir for their antiviral efficacy against the conventional viral strain. To verify the effect of the inactivation of virus particles, these extracts were added to each SARS-CoV-2 strain, and the infectious titers were determined using the TCID50 method. RESULTS: The antiviral efficacy (i.e., IC50) of the E. przewalskii extract against each SARS-CoV-2 strain was 2.7-10.8-fold greater than that of the E. sinica extract. The antiviral efficacy of the E. przewalskii extract against conventional viral strains was compared with that of remdesivir, which was 1/27.6 of remdesivir's efficacy. The E. sinica extract showed minimal inactivation of virus particles of each strain, whereas the E. przewalskii extract resulted in substantial viral inactivation. CONCLUSIONS: The E. przewalskii extract showed higher antiviral activity against SARS-CoV-2 than the E. sinica extract. Overall, our study suggests that E. przewalskii extract can be used for the treatment of viral infections, including COVID-19.

Effect of Segmented Optical Axial Length on the Performance of New-Generation Intraocular Lens Power Calculation Formulas in Extremely Long Eyes.

PURPOSE: To evaluate the performance of traditional vergence formulas with segmented axial length (AL) compared to traditional composite AL in extremely long eyes, and to determine whether the segmented AL can be extended to the new-generation formulas, including the Barrett Universal II, Emmetropia Verifying Optical 2.0 (EVO2), Hill-RBF 3.0 (Hill3), Kane, and Ladas Super formula (LSF) formulas in extremely long eyes. SETTING: National Hospital. Organization, Tokyo Medical Center, Japan. DESIGN: Retrospective case series. METHODS: Consecutive patients who underwent uncomplicated cataract surgery implanted with a three-piece intraocular lens between December 2015 and March 2021 were retrospectively reviewed. The composite AL was measured with a swept-source optical coherence tomography (SS-OCT) biometer using a mean refractive index. The segmented AL was calculated by summing the geometric lengths of the ocular segments (cornea, aqueous, lens, and vitreous) using multiple specific refractive indices based on the data obtained by the SS-OCT-based biometer. When refraction was measured at three months postoperatively, the median absolute errors (MedAEs) were calculated with two ALs for each formula. RESULTS: The study included 31 eyes of 22 patients. The segmented AL (30.45 ± 1.23 mm) was significantly shorter than the composite AL (30.71 ± 1.28 mm, p < 0.001). The MedAEs were significantly reduced when using segmented AL for SRK/T, Haigis, Hill3, and LSF, compared to those obtained using composite AL (0.38 vs. 0.62, 0.48 vs. 0.79, 0.50 vs. 0.90, 0.34 vs. 0.61, p < 0.001 for all formulas, respectively). On the contrary, the MedAE obtained by Kane with segmented AL was significantly worse compared to the one with composite AL (0.35 vs. 0.27, p = 0.03). CONCLUSION: In extremely high myopic eyes, the segmented AL improves the performance of SRK/T, Haigis, Hill3, and LSF formulas compared to the composite AL, while the segmented AL worsens the prediction accuracy of the Kane formula.

Computer Science Technology in Natural Products Research: A Review of Its Applications and Implications.

Computational approaches to drug development are rapidly growing in popularity and have been used to produce significant results. Recent developments in information science have expanded databases and chemical informatics knowledge relating to natural products. Natural products have long been well-studied, and a large number of unique structures and remarkable active substances have been reported. Analyzing accumulated natural product knowledge using emerging computational science techniques is expected to yield more new discoveries. In this article, we discuss the current state of natural product research using machine learning. The basic concepts and frameworks of machine learning are summarized. Natural product research that utilizes machine learning is described in terms of the exploration of active compounds, automatic compound design, and application to spectral data. In addition, efforts to develop drugs for intractable diseases will be addressed. Lastly, we discuss key considerations for applying machine learning in this field. This paper aims to promote progress in natural product research by presenting the current state of computational science and chemoinformatics approaches in terms of its applications, strengths, limitations, and implications for the field.

Dispersing attentional resources reduces negative emotions.

Research shows that human attentional focus expands under positive emotions and narrows under negative emotions. Moreover, expanding (or contracting) the attentional focus is associated with dispersing (or concentrating) attentional resources. This study investigated whether dispersing or concentrating attentional resources on a target stimulus can change negative emotions to positive ones. We used the flanker task to manipulate the attentional resource allocation range by displaying a peripheral, task-unrelated induction stimulus far from the target stimulus or a central, task-unrelated induction stimulus near the target stimulus. The attentional resources allocated to the target stimulus were measured by recording the P300 component, an event-related potential indicating attention allocation. We also presented negative images before and after the task and used the Self-Assessment Manikin and the Affect Grid to assess the negative emotions induced by the images. The P300 amplitudes for the target stimuli were smaller in the peripheral than in the central condition. Moreover, self-reported negative emotions in the peripheral condition decreased after the task but did not change in the central condition. The dispersion of attentional resources changes negative emotions into a positive orientation.

Effect of Taste-Induced Mood on ERP and Emotional Assessment of Images.

Tastes affect the body and our emotions. We used tasteless, sweet, and bitter stimuli to induce participants' moods, and we examined the effect of mood on an emotional evaluation of pleasant, neutral, and unpleasant images using event-related potentials, N2, N400, and late positive potential (LPP), which reflect emotional evaluation in the brain. The results indicated that mood valence was most positive for sweetness and most negative for bitterness. Moreover, there was no significant mood effect on subjective valence ratings of emotional images. Furthermore, the N2 amplitude, which is related to the early semantic processing of preceding stimuli, was unaffected by the taste induced mood. In contrast, we found that the N400 amplitude, which is related to the mismatch of emotional valence between stimuli, increased significantly for unpleasant images when participants were in a positive rather than negative mood state. Also, the LPP amplitude, which is related to the emotional valence of images, showed only the main effect of the images' emotional valence. The N2's results suggest that the early semantic processing of taste stimuli might have had a negligible impact on emotional evaluation because taste stimuli minimize semantic processing that accompanies mood induction. In contrast, the N400 reflected the effects of the induced mood, and the LPP reflected the impact of the valence of emotional images. The use of taste stimuli to induce mood revealed different brain processing of taste-induced mood effects on emotional evaluation, including N2's involvement in semantic processing, N400's involvement in matching emotions between mood and stimuli, and LPP's involvement in subjective evaluations of stimuli.

Effects of using a snooze alarm on sleep inertia after morning awakening.

BACKGROUND: Many people use the snooze function of digital alarm clocks for morning awakening, but the effects of a snooze alarm on waking are unclear. We examined the effects of a snooze alarm on sleep inertia, which is a transitional state characterized by reduced arousal and impaired cognitive and behavioral performance immediately upon awakening. METHODS: In study 1, healthy Japanese university students responded to a sleep survey during a psychology class (study 1), and we collected 293 valid responses. In study 2, we compared a separate sample of university students (n = 10) for the effects of using or not using a snooze alarm on sleep inertia immediately after awakening from normal nocturnal sleep in a sleep laboratory. RESULTS: Of 293 valid respondents in study 1, 251 often used a tool to wake up in the morning (85.7%). Moreover, 70.5% reported often using the snooze function of their mobile phones, mainly to reduce anxiety about oversleeping. Study 2 indicated no differences in the sleep quality or quantity before awakening with or without the snooze alarm, except in the last 20 min. However, during the last 20 min of sleep with snooze alarm, the snooze alarm prolonged waking and stage N1 sleep. Stage N1 sleep is non-rapid eye movement sleep that is primarily defined as a drowsy state. Furthermore, Global Vigor values were enhanced after awakening compared to pre-sleep in the no-snooze condition. CONCLUSIONS: Using a snooze alarm prolongs sleep inertia compared to a single alarm, possibly because snooze alarms induce repeated forced awakenings.

Effect of Seat Angle when Sleeping in a Car on Quality of Sleep and Its Impact on Calculation Performance the Following Day.

The number of occasions to stay in a car overnight is increasing during disasters; however, the effects on sleep and the impact on daytime functioning are not well understood. We investigated the effect of seat angle when sleeping in a car and its impact on calculation performance the following day. Fifteen healthy males participated in three trials (sleeping in a car with the front seat angled at 45° and 60° in a laboratory and sleeping at home); sleep and calculation performance the following day were compared. Increased wake after sleep onset and decreased slow-wave sleep were observed in the 60° trial, that is, near-vertical, compared with the others. Subjective sleep quality and calculation performance in the 45° and 60° trials were poorer than those in the home trial. The effect of seat angle on sleep was confirmed objectively, but not subjectively, suggesting that a large seat angle might cause sleep impairment.

Effect of positive emotions on perceptual processing of visual probes.

OBJECTIVES: The late positive potential (LPP) is an event-related potential that increases in response to emotional stimuli. Brown et al. investigated the functional significance of LPP. They induced the LPP by presenting unpleasant pictures and reported that N1 in response to a visual probe, which reflects perceptual processing in the visual cortex, was attenuated compared to N1 when neutral pictures induced the LPP. This finding suggested that visual cortex activity is inhibited during LPP elicitation (global inhibition hypothesis). However, they did not examine the activity of the visual cortex during LPP induced by pleasant pictures. Based on previous research reporting that positive emotions enhance motivation and cognitive activity (e.g. broaden and build theory), we hypothesize that perceptual processing of visual probes during LPP is enhanced by pleasant pictures, which increase N1 to the visual probe. METHODS: We investigated this hypothesis by presenting visual probes during LPP generated by emotional pictures following Brown et al. RESULTS: The results demonstrated that the N1 amplitude increased, and response times to visual probes decreased during the LPP induced by pleasant pictures compared to unpleasant pictures. CONCLUSIONS: These findings suggest that positive emotions elicited by pleasant pictures enhanced the perceptual processing of visual probes, which is suggestive of the approach function of LPP during positive emotional experiences.

Effective Search of Triterpenes with Anti-HSV-1 Activity Using a Classification Model by Logistic Regression.

Natural products are an excellent source of skeletons for medicinal seeds. Triterpenes and saponins are representative natural products that exhibit anti-herpes simplex virus type 1 (HSV-1) activity. However, there has been a lack of comprehensive information on the anti-HSV-1 activity of triterpenes. Therefore, expanding information on the anti-HSV-1 activity of triterpenes and improving the efficiency of their exploration are urgently required. To improve the efficiency of the development of anti-HSV-1 active compounds, we constructed a predictive model for the anti-HSV-1 activity of triterpenes by using the information obtained from previous studies using machine learning methods. In this study, we constructed a binary classification model (i.e., active or inactive) using a logistic regression algorithm. As a result of the evaluation of predictive model, the accuracy for the test data is 0.79, and the area under the curve (AUC) is 0.86. Additionally, to enrich the information on the anti-HSV-1 activity of triterpenes, a plaque reduction assay was performed on 20 triterpenes. As a result, chikusetsusaponin IVa (11: IC50 = 13.06 µM) was found to have potent anti-HSV-1 with three potentially anti-HSV-1 active triterpenes. The assay result was further used for external validation of predictive model. The prediction of the test compounds in the activity test showed a high accuracy (0.83) and AUC (0.81). We also found that this predictive model was found to be able to successfully narrow down the active compounds. This study provides more information on the anti-HSV-1 activity of triterpenes. Moreover, the predictive model can improve the efficiency of the development of active triterpenes by integrating many previous studies to clarify potential relationships.

Spontaneous and Immune Checkpoint Inhibitor-Induced Autoimmune Diseases: Analysis of Temporal Information by Using the Japanese Adverse Drug Event Report Database.

BACKGROUND AND OBJECTIVE: Immune checkpoint inhibitors (ICIs) such as programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte antigen 4 (CTLA-4) inhibitors have greatly improved cancer treatment. However, they are associated with immune-related adverse events, including autoimmune diseases (ADs) owing to their immune enhancement effect. As there are few comprehensive studies of ADs by ICIs, it is necessary to analyze the period information of drug-induced ADs. We also assumed that the temporal information may be useful to estimate the similarity of the pathogenic mechanism between spontaneous and ICI-induced ADs. METHODS: A period analysis including the Weibull analysis was performed on ICI-induced ADs using the Japanese Adverse Drug Event Report (JADER) database. For evaluating the similarity of spontaneous and ICI-induced ADs, a hierarchical cluster analysis was conducted to compare the different onset-time ranges. RESULTS: Type 1 diabetes mellitus, autoimmune colitis, and pemphigoid occurred earlier with CTLA-4 inhibitors (median: 46, 29.5 and 28 days, respectively) than with PD-1 inhibitors (> 130 days). Myasthenia gravis had a median time to onset of approximately 1 month, and the risk of onset would increase over time in ipilimumab combination therapy. This result reveals ADs that require attention. Using cluster analysis, we estimated six clusters with different patterns of onset times. Based on these results and a detailed previous research survey, the possible pathogenesis of drug-induced ADs was also discussed. CONCLUSIONS: This paper describes risk profiles with temporal information of ICI-induced ADs and proposes certain indicators for deciphering the mechanism of AD onset.

Resting Heart Rate Variability Is Associated With Subsequent Orthostatic Hypotension: Comparison Between Healthy Older People and Patients With Rapid Eye Movement Sleep Behavior Disorder.

Background: Orthostatic hypotension (OH) caused by autonomic dysfunction is a common symptom in older people and patients with idiopathic rapid eye movement sleep behavior disorder (iRBD). The orthostatic challenge test is a standard autonomic function test that measures a decrease of blood pressure during a postural change from supine to standing positions. Although previous studies have reported that changes in heart rate variability (HRV) are associated with autonomic dysfunction, no study has investigated the relationship between HRV before standing and the occurrence of OH in an orthostatic challenge test. This study aims to examine the connection between HRV in the supine position and the occurrence of OH in an orthostatic challenge test. Methods: We measured the electrocardiograms of patients with iRBD and healthy older people during an orthostatic challenge test, in which the supine and standing positions were held for 15 min, respectively. The subjects were divided into three groups: healthy controls (HC), OH-negative iRBD [OH (-) iRBD], and OH-positive iRBD [OH (+) iRBD]. HRV measured in the supine position during the test were calculated by time-domain analysis and Poincaré plots to evaluate the autonomic dysfunction. Results: Forty-two HC, 12 OH (-) iRBD, and nine OH (+) iRBD subjects were included. HRV indices in the OH (-) and the OH (+) iRBD groups were significantly smaller than those in the HC group. The multivariate logistic regression analysis for OH identification for the iRBD groups showed the model whose inputs were the HRV indices, i.e., standard deviation 2 (SD2) and the percentage of adjacent intervals that varied by more than 50 ms (pNN50), had a receiver operating characteristic curve with area under the curve of 0.840, the sensitivity to OH (+) of 1.000, and the specificity to OH (-) of 0.583 (p = 0.023). Conclusions: This study showed the possibility that short-term HRV indices in the supine position would predict subsequent OH in iRBD patients. Our results are of clinical importance in terms of showing the possibility that OH can be predicted using only HRV in the supine position without an orthostatic challenge test, which would improve the efficiency and safety of testing.

Evaluation of Sleep Quality in a Disaster Evacuee Environment.

We aimed to evaluate sleep and sleep-related physiological parameters (heart rate variability and glucose dynamics) among evacuees by experimentally recreating the sleep environment of evacuation shelters and cars. Nine healthy young male subjects participated in this study. Two interventions, modeling the sleep environments of evacuation shelters (evacuation shelter trial) and car seats (car trial), were compared with sleep at home (control trial). Physiological data were measured using portable two-channel electroencephalogram and electrooculogram monitoring systems, wearable heart rate sensors, and flash glucose monitors. Wake after sleep onset (WASO) and stage shift were greater in both intervention trials than the control trial, while rapid-eye movement (REM) latency and non-rapid eye movement (NREM) 1 were longer and REM duration was shorter in the evacuation shelter trial than the control trial. Glucose dynamics and power at low frequency (LF.p) of heart rate variability were higher in the car trial than in the control trial. It was confirmed that sleep environment was important to maintain sleep, and affected glucose dynamics and heart rate variability in the experimental situation.

Anterior insula activity and the effect of agency on the Stimulus-Preceding Negativity.

If you know that you are the author of a freely chosen action and that you bear responsibility for its outcome, then you are said to have "a sense of agency." When there is a delay between action and outcome, this response must be remembered if you are to learn from the experience. Previous studies have shown that the Stimulus-Preceding Negativity (SPN) recorded during the delay interval is larger under conditions that foster a sense of agency. In an EEG experiment (N = 27), we confirmed that the SPN is larger when participants have a choice between two responses in a gambling task as compared to when there is only a single button and the computer determines the monetary outcome. This SPN agency effect was largest over right prefrontal cortex and it did not vary significantly between trial blocks in which only gains or only losses were possible. Participants in a second experiment (N = 26) performed the same task while activity in anterior insular cortex, a known SPN generator, was measured via functional magnetic resonance image (fMRI). An essentially identical pattern of results was obtained: Activity was greater on choice than no-choice trials, especially for the right hemisphere, and no effect of contextual valence was observed. Although parallel observations such as these cannot warrant causal inference, our findings are consistent with the assumption that anterior insular cortex contributes to the effect of agency on the SPN.

Sleep Spindle Detection Using RUSBoost and Synchrosqueezed Wavelet Transform.

Sleep spindles are important electroencephalographic (EEG) waveforms in sleep medicine; however, it is burdensome even for experts to detect spindles, so automatic spindle detection methodologies have been investigated. Conventional methods utilize waveforms template matching or machine learning for detecting spindles. In the former approach, it is necessary to tune thresholds for individual adaptation, while the latter approach has the problem of imbalanced data because the amount of sleep spindles is small compared with the entire EEG data. The present work proposes a sleep spindle detection method that combines wavelet synchrosqueezed transform (SST) and random under-sampling boosting (RUSBoost). SST is a time-frequency analysis method suitable for extracting features of spindle waveforms. RUSBoost is a framework for coping with the imbalanced data problem. The proposed SST-RUS can deal with the imbalanced data in spindle detection and does not require threshold tuning because RUSBoost uses majority voting of weak classifiers for discrimination. The performance of SST-RUS was validated using an open-access database called the Montreal archives of sleep studies cohort 1 (MASS-C1), which showed an F-measure of 0.70 with a sensitivity of 76.9% and a positive predictive value of 61.2%. The proposed method can reduce the burden of PSG scoring.

New diterpenes from Nigella damascena seeds and their antiviral activities against herpes simplex virus type-1.

Nigella species are rich source of dolabellane diterpenes. During our study of Nigella species, new dolabellane diterpenes, damasterpenes V-VIII were isolated. The structural determination of new compounds damasterpenes V-VIII is described with consideration of their absolute configurations. The antiviral activities against herpes simplex virus type-1 of the isolated compounds and their derivatives are also evaluated. Damasterpene V (inhibition 35.0%) and 2-phenylacetyl 13-benzoyl damasterpenol (32.0%) showed significant antiviral activity at 10 µM.

Neolignan and megastigmane glucosides from the aerial parts of Isodon japonicus with cell protective effects on BaP-induced cytotoxicity.

Six neolignan glucosides, named isodonosides I-VI, and a megastigmane glucoside named isodonmegastigmane I, were isolated together with 15 known compounds from the methanolic extract of aerial parts of Isodon japonicus cultivated in Tokushima, Japan. The chemical structures of the compounds were elucidated based on their MS and NMR spectroscopic analysis. The absolute configurations of the neolignan and megastigmane glucosides were determined by derivatizations, by ECD (electronic circular dicroism) Cotton effect approximation, and by the modified Mosher's method. In addition, a significant cell protective effects of neolignan glucosides on benzo[a]pyrene-induced cytotoxicity was found.

Efficacy of Japanese traditional (Kampo) medicine for treating chemotherapy-induced peripheral neuropathy: A retrospective case series study.

AIM: To investigate Japanese traditional (Kampo) medicine's effectiveness on cancer chemotherapy-induced peripheral neuropathy (CIPN), we carried out this retrospective study. METHODS: By searching our outpatient database of 3154 patients who consulted our outpatient clinic of Japanese-Oriental (Kampo) Medicine at Chiba University Hospital from November 2005 to December 2010, a total of 281 patients diagnosed with cancer were identified. Twenty-four patients out of the 281 patients identified met the following three conditions and were eligible for further investigation of the effectiveness of Kampo treatment: At least one course of cancer chemotherapy had been administered; numbness and pain appeared after the chemotherapy; and CIPN was diagnosed before they were given Kampo treatment. RESULTS: The 24 patients included 6 males and 18 females and ranged in age from 39 to 86 (mean 61.2 ± 11.5) years old. Kampo formulas were individually chosen by Kampo expert doctors based on Kampo-specific diagnostics. Beneficial outcomes were obtained by Kampo treatment in 20 out of the 24 cases (83.3%). Nine out 20 cases had a major response (the numbness and pain showed improvement or reduction by 50% or more), with 7 of 9 cases showing a more than 70% symptom reduction. Eleven out of 20 cases showed a minor response (less than 50% symptom reduction), and 4 out of the 24 cases had no beneficial response. The most frequently used formula was goshajinkigan (GJG), followed by hachimijiogan (HJG) and keishibukuryogan. Thirteen of the 24 cases (54.2%) were prescribed aconite root-containing formulas including GJG and HJG. Aconite root has "warming" effects and ameliorates pain and numbness; 21 out of 24 cases (87.5%) in total used warming formulas such as aconite root-containing formulas to reduce CIPN. CONCLUSION: Our current study suggested that Kampo formulas chosen based on Kampo-specific diagnostics could be for treating CIPN that is refractory to conventional medicine.

Napping after complex motor learning enhances juggling performance.

The present study examined whether a nap after complex motor learning enhanced the following day's physical performance. Eighteen volunteers met the inclusion criteria and were assigned to either a nap (n=9; men=5; mean age=21.0±1.5) or no-nap group (n=9; men=5; mean age=21.9±0.3). Participants practiced juggling in the morning and were tested immediately afterwards. Participants of the nap group were given a 70-minute nap opportunity after juggling practice, while the no-nap group stayed awake. Juggling performance was then tested in the evening (retest-1) and the next morning (retest-2). Two-way analysis of variance (group: nap, no-nap×time: test, retest-1, retest-2) found there was a significant effect of test time and a significant group×time interaction. The juggling performance of both groups improved from test to retest-1, respectively. However, the juggling performance level of the nap group was higher than that of the no-nap group at the retest-1. As predicted, a nap promptly after learning motor skills was associated with subsequently improved performance. Moreover, the juggling performance of the nap group showed additional significant improvements in the retest-2. In the no-nap group, however, there were no significant improvements in the juggling performance after nocturnal sleep. These results demonstrate that the benefits of a nap following learning were further enhanced after nocturnal sleep. The present results may provide justification for introducing nap periods into daily athletic training as an active method to improve performance.