Neural Substrates of External and Internal Visual Sensations Induced by Human Intracranial Electrical Stimulation

Offline perceptions are self-generated sensations that do not involve physical stimulus. These perceptions can be induced by external hallucinated objects or internal imagined objects. However, how the brain dissociates these visual sensations remains unclear. We aimed to map the brain areas involved in internal and external visual sensations induced by intracranial electrical stimulation and further investigate their neural differences. In this study, we collected subjective reports of internal and external visual sensations elicited by electrical stimulation in 40 drug-refractory epilepsy during presurgical evaluation. The response rate was calculated and compared to quantify the dissociated distribution of visual responses. We found that internal and external visual sensations could be elicited when different brain areas were stimulated, although there were more overlapping brain areas. Specifically, stimulation of the hippocampus and inferior temporal cortex primarily induces internal visual sensations. In contrast, stimulation of the occipital visual cortex mainly triggers external visual sensations. Furthermore, compared to that of the dorsal visual areas, the ventral visual areas show more overlap between the two visual sensations. Our findings show that internal and external visual sensations may rely on distinct neural representations of the visual pathway. This study indicated that implantation of electrodes in ventral visual areas should be considered during the evaluation of visual sensation aura epileptic seizures

Analysis of RIG-I-mediated innate immune response in rats with Kidney-Yang Deficiency Syndrome and its change following Yougui pill administration

Kidney-Yang Deficiency Syndrome (KYDS) is closely bound up with the immune response of immunocompromised patients. The study is to investigate whether retinoic acid-inducible gene-I (RIG-I)-mediated innate immune responseparticipates in the development of KYDS in rats and evaluate the effect of Yougui pill (YGP) on the response in KYDS rats. KYDS rats were induced by intramuscular injection of hydrocortisone at the dose of 10 mg/kg/d for 15 days. YGP at concentrations of 2.43 g/kg/d and 4.86 g/kg/d were administered intragastrically to KYDS rats for 30 days. The resultsshowed that the body weight, urinary 17-hydroxycorticosteroid (17-OHCS) level, spleen size and spleen index in KYDS rats were significantly decreased compared with healthy control rats, while YGP treatment reversed them towards normal level in a dose-dependent manner. Moreover, KYDS challenge not only strikingly increased the mRNA and protein expression levels of RIG-I, tripartite motif containing 25 (TRIM25), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) but alsomarkedly enhanced the endogenous RIG-I polyubiquitination levels. Whereas, YGP treatment effectively reversed this tendency in a dose-dependent manner. In conclusion, these findings revealed that RIG-I-mediated innate immune response was closely bound up with the development of KYDS. And YGP exhibited certain anti-inflammatory effects on KYDS rats via inhibiting the RIG-I-mediated innate immune response

Analysis of RIG-I-mediated innate immune response in rats with Kidney-Yang Deficiency Syndrome and its change following Yougui pill administration

350-359Kidney-Yang Deficiency Syndrome (KYDS) is closely bound up with the immune response of immunocompromised patients. The study is to investigate whether retinoic acid-inducible gene-I (RIG-I)-mediated innate immune response participates in the development of KYDS in rats and evaluate the effect of Yougui pill (YGP) on the response in KYDS rats. KYDS rats were induced by intramuscular injection of hydrocortisone at the dose of 10 mg/kg/d for 15 days. YGP at concentrations of 2.43 g/kg/d and 4.86 g/kg/d were administered intragastrically to KYDS rats for 30 days. The results showed that the body weight, urinary 17-hydroxycorticosteroid (17-OHCS) level, spleen size and spleen index in KYDS rats were significantly decreased compared with healthy control rats, while YGP treatment reversed them towards normal level in a dose-dependent manner. Moreover, KYDS challenge not only strikingly increased the mRNA and protein expression levels of RIG-I, tripartite motif containing 25 (TRIM25), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) but also markedly enhanced the endogenous RIG-I polyubiquitination levels. Whereas, YGP treatment effectively reversed this tendency in a dose-dependent manner. In conclusion, these findings revealed that RIG-I-mediated innate immune response was closely bound up with the development of KYDS. And YGP exhibited certain anti-inflammatory effects on KYDS rats via inhibiting the RIG-I-mediated innate immune response

DrugCLIP: Contrastive Protein-Molecule Representation Learning for Virtual Screening

Virtual screening, which identifies potential drugs from vast compound databases to bind with a particular protein pocket, is a critical step in AI-assisted drug discovery. Traditional docking methods are highly time-consuming, and can only work with a restricted search library in real-life applications. Recent supervised learning approaches using scoring functions for binding-affinity prediction, although promising, have not yet surpassed docking methods due to their strong dependency on limited data with reliable binding-affinity labels. In this paper, we propose a novel contrastive learning framework, DrugCLIP, by reformulating virtual screening as a dense retrieval task and employing contrastive learning to align representations of binding protein pockets and molecules from a large quantity of pairwise data without explicit binding-affinity scores. We also introduce a biological-knowledge inspired data augmentation strategy to learn better protein-molecule representations. Extensive experiments show that DrugCLIP significantly outperforms traditional docking and supervised learning methods on diverse virtual screening benchmarks with highly reduced computation time, especially in zero-shot setting

Spherical Indicatrices of a Bertrand Curve in Three Lie Groups

In this paper, new representations of a Bertrand curve pair in three dimensional Lie groups with bi-invariant metric are given. Besides, the spherical indicatrices of a Bertrand curve pair are obtain and the relations between the spherical indicatrices and new representations of Bertrand curve pair are shown.Comment: 12 page

Evolution of emergent monopoles into magnetic skyrmion strings

Topological defects are fundamental concepts in physics, but little is known about the transition between distinct types across different dimensionalities. In topological magnetism, as in field theory, the transition between 1D strings and 0D monopoles is a key process whose observation has remained elusive. Here, we introduce a novel mechanism that allows for the controlled stabilization of emergent monopoles and show that magnetic skyrmion strings can be folded into monopoles. Conversely, they act as seeds out of which the entire string structure can unfold, containing its complete information. In chiral magnets, this process can be observed by resonant elastic X-ray scattering when the objects are in proximity to a polarized ferromagnet, whereby a pure monopole lattice is emerging on the surface. Our experimental proof of the reversible evolution from monopole to string sheds new light on topological defects and establishes the emergent monopole lattice as a new 3D topological phase

Neural Activity Is Dynamically Modulated by Memory Load During the Maintenance of Spatial Objects

Visuospatial working memory (WM) is a fundamental but severely limited ability to temporarily remember selected stimuli. Several studies have investigated the underlying neural mechanisms of maintaining various visuospatial stimuli simultaneously (i.e., WM load, the number of representations that need to be maintained in WM). However, two confounding factors, namely verbal representation and encoding load (the number of items that need to be encoded into WM), have not been well controlled in previous studies. In this study, we developed a novel delayed-match-to-sample task (DMST) controlling for these two confounding factors and recorded scalp EEG signals during the task. We found that behavioral performance deteriorated severely as memory load increased. Neural activity was modulated by WM load in a dynamic manner. Specifically, higher memory load induced stronger amplitude in occipital and central channel-clusters during the early delay period, while the inverse trend was observed in central and frontal channel-clusters during late delay. In addition, the same inverse memory load effect, that was lower memory load induced stronger amplitude, was observed in occipital channel-cluster alpha power during late delay. Finally, significant correlations between neural activity and individual reaction time showed a role of late-delay central and frontal channel-cluster amplitude in predicting behavioral performance. Because the occipital cortex is important for visual information maintenance, the decrease in alpha oscillation was consistent with the cognitive role that is “gating by inhibition.” Together, our results from a well-controlled DMST suggest that WM load not exerted constant but dynamic effect on neural activity during maintenance of visuospatial objects

Enhancement of hydrogen physisorption on single-walled carbon nanotubes resulting from defects created by carbon bombardment

The defect effect on hydrogen adsorption on single-walled carbon nanotubes (SWNTs) has been studied by using extensive molecular dynamics simulations and density functional theory (DFT) calculations. It indicates that the defects created on the exterior wall of the SWNTs by bombarding the tube wall with carbon atoms and C-2 dimers at a collision energy of 20 eV can enhance the hydrogen adsorption potential of the SWNTs substantially. The average adsorption energy for a H-2 molecule adsorbed on the exterior wall of a defected (10,10) SWNT is similar to 150 meV, while that for a H-2 molecule adsorbed on the exterior wall of a perfect (10,10) SWNT is similar to 104 meV. The H-2 sticking coefficient is very sensitive to temperature, and has a maximum value around 70 to 90 K. The electron density contours, the local density of states, and the electron transfers obtained from the DFT calculations clearly indicate that the H-2 molecules are all physisorbed on the SWNTs. At temperatures above 200 K, most of the H-2 molecules adsorbed on the perfect SWNT are soon desorbed, but the H-2 molecules can still remain on the defected SWNTs at 300 K. The detailed processes of H-2 molecules adsorbing on and desorbing from the (10,10) SWNTs are demonstrated

Attenuation of Mycoplasma hyopneumoniae Strain ES-2 and Comparative Genomic Analysis of ES-2 and Its Attenuated Form ES-2L

Mycoplasma hyopneumoniae causes swine respiratory disease worldwide. Due to the difficulty of isolating and cultivating M. hyopneumoniae, very few attenuated strains have been successfully isolated, which hampers the development of attenuated vaccines. In order to produce an attenuated M. hyopneumoniae strain, we used the highly virulent M. hyopneumoniae strain ES-2, which was serially passaged in vitro 200 times to produce the attenuated strain ES-2L, and its virulence was evidenced to be low in an animal experiment. In order to elucidate the mechanisms underlying virulence attenuation, we performed whole-genome sequencing of both strains and conducted comparative genomic analyses of strain ES-2 and its attenuated form ES-2L. Strain ES-2L showed three large fragment deletion regions including a total of 18 deleted genes, compared with strain ES-2. Analysis of single-nucleotide polymorphisms (SNPs) and indels indicated that 22 dels were located in 19 predicted coding sequences. In addition to these indels, 348 single-nucleotide variations (SNVs) were identified between strains ES-2L and ES-2. These SNVs mapped to 99 genes where they appeared to induce amino acid substitutions and translation stops. The deleted genes and SNVs may be associated with decreased virulence of strain ES-2L. Our work provides a foundation for further examining virulence factors of M. hyopneumoniae and for the development of attenuated vaccines