Contrast, Attend and Diffuse to Decode High-Resolution Images from Brain Activities

Decoding visual stimuli from neural responses recorded by functional Magnetic Resonance Imaging (fMRI) presents an intriguing intersection between cognitive neuroscience and machine learning, promising advancements in understanding human visual perception and building non-invasive brain-machine interfaces. However, the task is challenging due to the noisy nature of fMRI signals and the intricate pattern of brain visual representations. To mitigate these challenges, we introduce a two-phase fMRI representation learning framework. The first phase pre-trains an fMRI feature learner with a proposed Double-contrastive Mask Auto-encoder to learn denoised representations. The second phase tunes the feature learner to attend to neural activation patterns most informative for visual reconstruction with guidance from an image auto-encoder. The optimized fMRI feature learner then conditions a latent diffusion model to reconstruct image stimuli from brain activities. Experimental results demonstrate our model's superiority in generating high-resolution and semantically accurate images, substantially exceeding previous state-of-the-art methods by 39.34% in the 50-way-top-1 semantic classification accuracy. Our research invites further exploration of the decoding task's potential and contributes to the development of non-invasive brain-machine interfaces.Comment: 17 pages, 6 figures, conferenc

Experimental study on effects of gas flow rate on soot characteristics in diffusion flames coupled with plasma

This study examined the evolution of morphology and nanostructure of soot particles from the plasma-flame interaction for various gas flow rates. The current study used both optical diagnostic and sampling methods to explore the soot production and combustion characteristics. Soot particles were characterized at the same positions downstream from the flame zone by thermophoretic sampling and transmission electron microscopy. Moreover, X-ray diffraction analysis, and thermogravimetric analysis were performed to study the nanostructure and oxidation reactivity of soot. A reduction in soot concentration was found with the plasma addition, which illustrated an inhibition effect of plasma on soot emission. The increased gas flow rate promoted soot concentration since a growing number of carbons participated in the combustion process. Depending on the gas flow rate (carbon content) variation and plasma activation, either liquid-like soot material with irregularly shaped protrusions or chain-like structure, or a mixture of both, were generated from the diffusion flames. The soot produced by plasma-flame interaction also demonstrated a high correlation between nanostructure and reactivity. The soot from lower carbon content with plasma activation had a shorter fringe length and larger fringe tortuosity related to higher oxidation reactivity. On the contrary, soot from the highest carbon content without plasma-flame interaction exhibited prevalent fullerene-like nanostructures with evident large or small shells and also had a higher carbonization degree resulting in lower oxidation reactivity

Regulation of welding residual stress in laser-welded AISI 304 steel-niobium joints using a Cu interlayer

Residual stress and deformation in a welded joint will significantly reduce its service life, and thus the analysis and regulation of residual stresses are very important. In this paper, a SYSWELD software was used to numerically simulate the temperature field, residual stress field, and the welding deformation during welding with and without a Cu interlayer. Thermocouples were used to measure the thermal cycle curves, and X-ray diffraction (XRD) was used to measure the residual stresses of the joints. The results show that the addition of a Cu interlayer does not significantly change the temperature field, and that the high temperature region on the niobium side is wider. In addition, the peak temperature in the centre of the welds and the temperature gradient perpendicular to the weld are greatly reduced by a Cu interlayer. Furthermore, a Cu interlayer contributes to a certain increase in both transverse and longitudinal residual stresses. Because the weld involves three different materials, steel, niobium, and Cu, the residual stresses in the welds are more complex. The simulation of the welding deformation shows that the transverse shrinkage in the thickness direction can be homogenized by the Cu interlayer, which leads to a significant reduction in deformation.acceptedVersio

Derivation and Characterization of Hepatic Progenitor Cells from Human Embryonic Stem Cells

The derivation of hepatic progenitor cells from human embryonic stem (hES) cells is of value both in the study of early human liver organogenesis and in the creation of an unlimited source of donor cells for hepatocyte transplantation therapy. Here, we report for the first time the generation of hepatic progenitor cells derived from hES cells. Hepatic endoderm cells were generated by activating FGF and BMP pathways and were then purified by fluorescence activated cell sorting using a newly identified surface marker, N-cadherin. After co-culture with STO feeder cells, these purified hepatic endoderm cells yielded hepatic progenitor colonies, which possessed the proliferation potential to be cultured for an extended period of more than 100 days. With extensive expansion, they co-expressed the hepatic marker AFP and the biliary lineage marker KRT7 and maintained bipotential differentiation capacity. They were able to differentiate into hepatocyte-like cells, which expressed ALB and AAT, and into cholangiocyte-like cells, which formed duct-like cyst structures, expressed KRT19 and KRT7, and acquired epithelial polarity. In conclusion, this is the first report of the generation of proliferative and bipotential hepatic progenitor cells from hES cells. These hES cell–derived hepatic progenitor cells could be effectively used as an in vitro model for studying the mechanisms of hepatic stem/progenitor cell origin, self-renewal and differentiation

Lifor Solution: An Alternative Preservation Solution in Small Bowel Transplantation

Background and Objectives. The intestinal mucosa is extremely sensitive to ischemia. Better intestinal preservation is the first step to improve the results of intestinal transplantation. The aim of the study is to investigate the effect of cold Lifor solution on preservation of swine small bowel. Methods. Swine ileum segments (200 cm) were allotransplanted heterotopically after 9-hour cold storage with UW solution (group 1, n=6), with Lifor solution (group 2, n=6), or without storage (group 3, n=6), respectively. After cold storage, mucosal adenosine triphosphate (ATP) concentrations and histopathologic analysis after preservation were performed. At day 7 after the transplantation, intestinal absorptive function was also observed. Results. After 9 h cold preservation, pathological changes, the content of ATP in the intestinal mucosa, and the intestinal absorptive function after transplantation in group 2 were similar to those of group 1. Conclusion. The effect of cold storage of swine small bowel with Lifor solution is similar to that of UW solution. It may provide additional rationale for further exploration of Lifor as an alternative preservation solution in small bowel transplantation

Undergraduates' perceptions on emergency remote learning in ecology in the post‐pandemic era

The COVID-19 pandemic has strongly disrupted academic activities, particularly in disciplines with a strong empirical component among other reasons by limiting our mobility. It is thus essential to assess emergency remote teaching plans by surveying learners’ opinions and perceptions during these unusual circumstances. To achieve this aim, we conducted a survey during the spring semester of 2021 in an environmental science program to ascertain learners’ perceptions on online and onsite learning activities in ecology-based modules. We were particularly interested not only in comparing the performance of these two types of activities but also in understanding the role played by learners’ perceptions about nature in shaping this pattern. Environmental science programs are rather heterogeneous from a conceptual point of view and, thus, learners may also be more diverse than in traditional ecology programs, which may affect their interest for ecology-based modules. We assessed connectedness to nature by computing the reduced version of the Nature Relatedness Scale. Here, we found that online activities systematically obtained significantly lower scores than onsite activities regardless of the wording employed, and that altruistic behaviors were prevalent among learners. Interestingly, scores for both onsite and online activities were strongly influenced by learners’ connectedness to nature, as learners with a stronger connection to nature gave higher scores to both types of activities. Our results suggest that an effort to improve the efficacy of remote learning activities should be the focus of research about teaching methodologies in predominantly empirical scientific disciplines

Effects of Electroacupuncture on Facial Nerve Function and HSV-1 DNA Quantity in HSV-1 Induced Facial Nerve Palsy Mice

Acupuncture is a common and effective therapeutic method to treat facial nerve palsy (FNP). However, its underlying mechanism remains unclear. This study was aimed to investigate the effects of electroacupuncture on symptoms and content of HSV-1 DNA in FNP mice. Mice were randomized into four groups, an electroacupuncture treatment group, saline group, model animal group, and blank control group. Electroacupuncture was applied at Jiache (ST6) and Hegu (LI4) in electroacupuncture group once daily for 14 days, while electroacupuncture was not applied in model animal group. In electroacupuncture group, mice recovered more rapidly and HSV-1 DNA content also decreased more rapidly, compared with model animal group. We conclude that electroacupuncture is effective to alleviate symptoms and promote the reduction of HSV-1 in FNP

Application of Acupoints and Meridians for the Treatment of Primary Dysmenorrhea: A Data Mining-Based Literature Study

Background. Dysmenorrhea is a common problem for which acupuncture provides effective analgesia. Although acupoint selection affects the effectiveness of acupuncture, the basic rules of acupoint selection are little understood. This study aims to investigate the principles of acupoint selection and characteristics of acupoints used for primary dysmenorrhea. Methods. PubMed, China National Knowledge Infrastructure, and Chinese Biomedical Database were searched for clinical trials published in English or Chinese from January 1978 to April 2014 evaluating the effect of acupuncture on primary dysmenorrhea, with or without methods of randomization and/or control. Three authors extracted information and two reviewers inputted information on titles, journals, interventions, main acupoints, and outcomes using the self-established Data Excavation Platform of Acupoint Specificity for data mining. Results. Sanyinjiao (SP06), Guanyuan (CV04), and Qihai (CV06) were used most frequently. The most frequently used meridians were Conception Vessel, Spleen Meridian of Foot Taiyin, and Bladder Meridian of Foot Taiyang. 67.24% of acupoints used were specific acupoints. Acupoints on lower limbs were most frequently used. Conclusion. Data mining is a feasible approach to identify the characteristics of acupoint selection. Our study indicated that modern acupuncture treatment for primary dysmenorrhea is based on selection of specific acupoints according to traditional acupuncture theory

Effectiveness Study of Moxibustion on Pain Relief in Primary Dysmenorrhea: Study Protocol of a Randomized Controlled Trial

Dysmenorrhea is a prevalent problem in menstruating women. As a nonpharmacologic and free of relevant side effects intervention, moxibustion is considered as a safe treatment and has long been recommended for dysmenorrhea in China. However, the exact effects of moxibustion in PD have not been fully understood. Therefore we designed this random clinical trial aiming to (1) investigate whether moxibustion is safe and effective for pain relief in primary dysmenorrhea when compared to conventional pain-killers and (2) assess the acceptability and side effects associated with moxibustion. The results of this trial will contribute to a better understanding of the different effects of moxibustion in pain relief in primary dysmenorrhea when compared to conventional pharmacologic pain treatment