34 research outputs found

    A large calcium-imaging dataset reveals a systematic V4 organization for natural scenes

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    The visual system evolved to process natural scenes, yet most of our understanding of the topology and function of visual cortex derives from studies using artificial stimuli. To gain deeper insights into visual processing of natural scenes, we utilized widefield calcium-imaging of primate V4 in response to many natural images, generating a large dataset of columnar-scale responses. We used this dataset to build a digital twin of V4 via deep learning, generating a detailed topographical map of natural image preferences at each cortical position. The map revealed clustered functional domains for specific classes of natural image features. These ranged from surface-related attributes like color and texture to shape-related features such as edges, curvature, and facial features. We validated the model-predicted domains with additional widefield calcium-imaging and single-cell resolution two-photon imaging. Our study illuminates the detailed topological organization and neural codes in V4 that represent natural scenes.Comment: 39 pages, 14 figure

    Restless Legs Syndrome in Chinese Patients With Sporadic Amyotrophic Lateral Sclerosis

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    Objective: To evaluate the frequency and clinical features of restless legs syndrome (RLS) in a group of Chinese patients with amyotrophic lateral sclerosis (ALS).Methods: 109 Patients included in this study fulfilled the revised El Escorial diagnostic criteria for clinically definite, probable and lab-supported probable ALS, and a group of 109 control subjects was matched for age and sex to the ALS group. Disease severity was assessed by the revised ALS functional rating scale (ALSFRS-R). The diagnosis of RLS was made according to the criteria of the International RLS Study Group. Other characteristics including sleep quality, excessive daytime sleepiness (EDS), REM sleep behavior disorder (RBD), depression and anxiety were also evaluated in ALS patients.Results: RLS was significantly more frequent in ALS patients than in control subjects (14.6 vs. 0.9%; P < 0.05). Compared to those without RLS, ALS patients with RLS reported a higher frequency of anxiety and EDS. ALS patients with RLS showed more severe legs dysfunction. EDS and legs function scores of the ALSFRS-R were independent factors significantly associated with RLS in ALS patients.Conclusions: Our findings suggest that Chinese ALS patients exhibit a high frequency of RLS symptoms and that these patients may benefit from recognition of the condition and optimized management of its symptoms. Moreover, ALS patients might cause circadian rhythms disturbance and our study further supports that ALS is a heterogeneous disorder involving multiple systems; further studies are needed to confirm these preliminary findings

    Diagnostic Performance of Neurofilaments in Chinese Patients With Amyotrophic Lateral Sclerosis: A Prospective Study

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    Several studies have attempted to reduce diagnostic delay and identify biomarkers for drug development in amyotrophic lateral sclerosis (ALS). In this study, we aimed to evaluate the diagnostic accuracy for ALS of cerebrospinal fluid (CSF) neurofilament (Nf), Tau protein, and inflammatory factors such as interleukin (IL)-2, IL-6, IL-10, IL-15, and granulocyte-macrophage colony-stimulating factor (GMCSF) in Chinese patients. Our prospective study measured the concentration of phosphorylated Nf heavy chain (pNfH), Nf light chain (NfL), Tau, pTau, and inflammatory factors in the CSF of 85 patients. Detailed clinical data and laboratory, neuroimaging, and neurophysiological findings were recorded. The concentrations of pNfH and NfL were higher in the ALS group than in the control group. At the 1104 pg/mL pNfH cutoff, the specificity was 68.8%, the sensitivity 100%, and the area under the curve (AUC) 0.907. At the 1,139 pg/mL NfL cutoff, the specificity was 56.3%, the sensitivity 96.2%, and the AUC 0.775. There was no significant difference in the concentrations of Tau, pTau, IL-2, IL-6, IL-10, IL-15, and GMCSF between the ALS and control groups (p > 0.05). In the ALS group, the concentration of pNfH in the CSF was correlated with disease duration (r = −0.475, p < 0.001). This is the first prospective study to confirm the diagnostic value of Nf for ALS in Chinese patients

    Neurofilaments in CSF as diagnostic biomarkers in motor neuron disease: a meta-analysis

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    AbstractObjective: Neurofilaments in CSF are promising biomarkers which might help in the diagnosis of motor neuron disease (MND). We aim to assess the diagnostic value of neurofilaments in CSF for MND.Methods: Pubmed, Emabase and Web of Science were searched for relevant studies systematically. Articles in English that evaluated the utility of neurofilaments in CSF in the diagnosis of MND were included. Data were extracted by two independent investigators. Diagnostic indexes for neurofilament light chain (NFL) and phosphorylated neurofilament heavy chain (pNFH) were calculated separately. Stata 12.0 software with a bivariate mixed-effects model was used to summarize the diagnostic indexes from eligible studies.Results: Five studies on NFL and eight studies on pNFH met inclusion criteria. For NFL, the pooled sensitivity and specificity were 81% (95% confidence interval CI, 72%-88%) and 85% (95%CI, 76%-91%), respectively; the positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were 5.5 (95%CI, 3.1-9.8) and 0.22 (95%CI, 0.14-0.35), respectively; the summary diagnostic odds ratio (DOR) was 25 (95%CI, 9-70), and the area under summary receiver operator characteristic curve (AUC) was 0.90 (95%CI, 0.87-0.92). For pNFH, the pooled sensitivity, specificity, PLR and NLR were 85% (95% CI, 80%-88%), 85% (95%CI, 77%-90%), 5.5 (95%CI, 3.6-8.4) and 0.18 (95%CI, 0.13-0.25) respectively; the DOR was 30 (95%CI, 16-58), and the AUC was 0.91 (95%CI, 0.88-0.93).Conclusion: Neurofilaments in CSF have a high value in the diagnosis of MND, though the optimal cutoff value remains to be further investigated

    Neuronal intranuclear inclusion disease misdiagnosed as Parkinson’s disease: a case report

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    Neuronal intranuclear inclusion disease (NIID) is a rare progressive neurodegenerative disease that mainly manifests as dementia, muscle weakness, sensory disturbances, and autonomic nervous dysfunction. Herein, we report a 68-year-old Chinese woman who was hospitalized because of resting tremor and bradykinesia that had been present for 7 years. Five years prior, bradykinesia and hypermyotonia had become apparent. She had urinary incontinence and rapid eye movement sleep behavior disorder. She was diagnosed with Parkinson’s disease (PD) and received levodopa and pramipexole, which relieved her motor symptoms. During hospitalization, diffusion-weighted imaging revealed a high-intensity signal along the cortical medullary junction. Moreover, a skin biopsy revealed the presence of intranuclear inclusions in adipocytes, fibroblasts, and sweat gland cells. NIID was diagnosed by testing the Notch 2 N-terminal-like C ( NOTCH2NLC ) gene. We report this case to remind doctors to consider NIID when diagnosing patients with symptoms indicative of Parkinson’s disease. Moreover, we note that further research is needed on the mechanism by which levodopa is effective for NIID

    The Bibliometric Analysis of Microplastics in Soil Environments: Hotspots of Research and Trends of Development

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    Microplastics are persistent and complex contaminants and have been recognized as a global concern. Recently, increasing efforts have been devoted to studying the influence of microplastics on soils. However, the complexity of microplastics and the diversity of extraction methods result in a lack of systematic analysis and comprehensive review in this field. In this paper, we used CiteSpace software to summarize the development of this field. Then, we visualized and analyzed the knowledge structure, research hotspots, and trend directions of this field. We found that the number of publications escalated dramatically, and 281 institutions in 69 countries have published articles in this field. Among them, China was the most productive contributor. However, according to the scientific collaboration analysis, we found that more than 90% of the authors who contributed to the field had no close connection. In co-occurrence analysis for subject categories, we found that the research in this field covered environmental science, engineering, ecology, and agriculture. Additionally, the effect of soil microplastics on agriculture was the most important problem in scientific research. The keyword co-occurrence cluster analysis revealed a total of 6 clusters, including “Identification” (#0), “Microbial community” (#1), “Oxidative stress” (#2), “Adsorption” (#3), “Porous media” (#4), and “Abundance” (#5). We discussed several aspects in detail, including detection methods, characteristics, environmental effects, adsorption capacity, removal and degradation, and toxicity. According to these results, we summarized the current research hotspots and evaluated future research trends in soil microplastics. This study is the first to specifically visualize the research field, and these results provide a reference for future research in the field of soil microplastics

    A New Model and Its Application for the Dynamic Response of RGO Resistive Gas Sensor

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    An reduced graphene oxide (RGO) resistive gas sensor was prepared to detect ammonia at room temperature, the result indicated that the desorption of gas (NH 3 ) molecules from a graphene-based sensor was difficult, which lead to a baseline drift. The responses of different concentrations were compared and studied. It was found that both the response rate and its acceleration were affected by the gas concentration. An Intermolecular Forces Based Model was established to explain the adsorption and desorption dynamic response curves. A new method was proposed based on this model. The first and second derivative extrema (FSDE) of the response curve can be attained quickly to calibrate the gas concentrations. The experiment results demonstrated that this new method could eliminate the baseline drift and was capable of increasing the efficiency of gas calibration significantly
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