213 research outputs found
Calibration Methods of Laser-Induced Breakdown Spectroscopy
Laser-induced breakdown spectroscopy (LIBS) has gained great attention over the past two decades due to its many advantages, such as needless sample preparation, capability of remote measurement and fast multielement simultaneous analysis. However, because of its inherent uncertainty features of plasma, it is still a big challenge for LIBS community worldwide to realize high sensitivity and accurate quantitative analysis. Currently, many chemometric analytical methods have been applied to LIBS calibration analysis, including univariate regression, multivariate regression, principal component regression (PCR), partial least squares regression (PLSR) and so on. In addition, appropriate sample and spectral pretreatment can effectively improve the analytical performance (i.e., limit of detection (LOD), accuracy and repeatability) of LIBS. In this chapter, we briefly summarize the progress of these calibration methods and their applications on LIBS and provide our recommendations
The determinants of public acceptance of telemedicine apps: an innovation diffusion perspective
With the rapid advancement of information technology, telemedicine apps have gradually become an indispensable tool for providing patients with more convenient, efficient, and accessible healthcare services. However, the successful implementation of these apps largely depends on widespread acceptance among the public. To thoroughly investigate the factors influencing the public’s acceptance of these apps and the relationships between these factors, this study developed a theoretical model based on the Diffusion of Innovation theory and the Theory of Perceived Value. To validate this model, we conducted a survey of 387 residents in Beijing, China, and employed structural equation modeling to analyze the collected data. The research findings indicate that attributes of innovation diffusion, including relative advantage, compatibility, complexity, trialability, and observability, significantly and positively influence the public’s perceived value. Particularly noteworthy is that perceived value partially mediates the relationship between innovation attributes and public acceptance, emphasizing the crucial role of perceived value in the public decision-making process. This study employed a theory-driven approach to elucidate the acceptance of telemedicine apps and offers fresh insights into the existing literature. By integrating the research paradigms of innovation diffusion and customer perceived value, we provide a coherent explanation of how individual cognitive processes lead to acceptance behavior. In summary, this research enriches the existing theoretical studies on the acceptance of telemedicine apps and holds positive implications for healthcare practice
catena-Poly[[aquadipyridinecopper(II)]-μ-fumarato]
The title compound, [Cu(C4H2O4)(C5H5N)2(H2O)]n, is a one-dimensional coordination polymer based on pyridine and fumarate ligands. Each CuII cation is coordinated by two carboxylate O atoms belonging to two fumarate anions, two N atoms from two pyridine molecules and one water molecule, in a square-based pyramidal geometry. Each fumarate anion bridges two CuII cations through the two carboxylate groups in a bis-monodentate fashion to form a one-dimensional polymeric chain along the c axis. Neighbouring chains are linked together to form a two-dimensional network parallel to the ac plane via hydrogen bonding interactions between uncoordinated carboxylate O atoms and coordinated water molecules of adjecent chains
Constraint-based automatic symmetry detection
10.1109/ASE.2013.66930622013 28th IEEE/ACM International Conference on Automated Software Engineering, ASE 2013 - Proceedings15-2
Inflammation-Mediated Memory Dysfunction and Effects of a Ketogenic Diet in a Murine Model of Multiple Sclerosis
A prominent clinical symptom in multiple sclerosis (MS), a progressive disorder of the central nervous system (CNS) due to heightened neuro-inflammation, is learning and memory dysfunction. Here, we investigated the effects of a ketogenic diet (KD) on memory impairment and CNS-inflammation in a murine model of experimental autoimmune encephalomyelitis (EAE), using electrophysiological, behavioral, biochemical and in vivo imaging approaches. Behavioral spatial learning deficits were associated with motor disability in EAE mice, and were observed concurrently with brain inflammation. The KD improved motor disability in the EAE model, as well as CA1 hippocampal synaptic plasticity (long-term potentiation) and spatial learning and memory (assessed with the Morris Water Maze). Moreover, hippocampal atrophy and periventricular lesions in EAE mice were reversed in KD-treated EAE mice. Finally, we found that the increased expression of inflammatory cytokines and chemokines, as well as the production of reactive oxygen species (ROS), in our EAE model were both suppressed by the KD. Collectively, our findings indicate that brain inflammation in EAE mice is associated with impaired spatial learning and memory function, and that KD treatment can exert protective effects, likely via attenuation of the robust immune response and increased oxidative stress seen in these animals
Experimental observation of Dirac-like surface states and topological phase transition in PbSnTe(111) films
The surface of a topological crystalline insulator (TCI) carries an even
number of Dirac cones protected by crystalline symmetry. We epitaxially grew
high quality PbSnTe(111) films and investigated the TCI phase by
in-situ angle-resolved photoemission spectroscopy. PbSnTe(111)
films undergo a topological phase transition from trivial insulator to TCI via
increasing the Sn/Pb ratio, accompanied by a crossover from n-type to p-type
doping. In addition, a hybridization gap is opened in the surface states when
the thickness of film is reduced to the two-dimensional limit. The work
demonstrates an approach to manipulating the topological properties of TCI,
which is of importance for future fundamental research and applications based
on TCI
Nicotinic Receptor β2 Determines Nk Cell-Dependent Metastasis In A Murine Model Of Metastatic Lung Cancer
Cigarette smoke exposure markedly compromises the ability of the immune system to protect against invading pathogens and tumorigenesis. Nicotine is a psychoactive component of tobacco products that acts as does the natural neurotransmitter, acetylcholine, on nicotinic receptors (nAChRs). Here we demonstrate that natural killer (NK) cells strongly express nAChR β2. Nicotine exposure impairs the ability of NK cells to kill target cells and release cytokines, a process that is largely abrogated by nAChR β2 deficiency. Further, nicotinic suppression of NF-κB-induced transcriptional activity in NK cells is dependent on nAChR β2. This nAChR subtype also plays a large role in the NK cell-mediated control of melanoma lung metastasis, in a murine lung metastasis model exposed to nicotine. Our findings suggest nAChR β2 as a prominent pathway for nicotine induced impairment of NK cell functions which contributes to the occurrence of smoking-related pathologies. © 2013 Hao et al
Eight-input optical programmable logic array enabled by parallel spectrum modulation
Despite over 40 years' development of optical logic computing, the studies
have been still struggling to support more than four operands, since the high
parallelism of light has not been fully leveraged blocked by the optical
nonlinearity and redundant input modulation in existing methods. Here, we
propose a scalable multi-input optical programmable logic array (PLA) with
minimal logical input, enabled by parallel spectrum modulation. By making full
use of the wavelength resource, an eight-input PLA is experimentally
demonstrated, and there are 2^256 possible combinations of generated logic
gates. Various complex logic fuctions, such as 8-256 decoder, 4-bit comparator,
adder and multiplier are experimentally demonstrated via leveraging the PLA.
The scale of PLA can be further extended by fully using the dimensions of
wavelength and space. As an example, a nine-input PLA is implemented to realize
the two-dimensional optical cellular automaton for the first time and perform
Conway's Game of Life to simulate the evolutionary process of cells. Our work
significantly alleviates the challenge of extensibility of optical logic
devices, opening up new avenues for future large-scale, high-speed and
energy-efficient optical digital computing
Valley: Video Assistant with Large Language model Enhanced abilitY
Large language models (LLMs), with their remarkable conversational
capabilities, have demonstrated impressive performance across various
applications and have emerged as formidable AI assistants. In view of this, it
raises an intuitive question: Can we harness the power of LLMs to build
multimodal AI assistants for visual applications? Recently, several multi-modal
models have been developed for this purpose. They typically pre-train an
adaptation module to align the semantics of the vision encoder and language
model, followed by fine-tuning on instruction-following data. However, despite
the success of this pipeline in image and language understanding, its
effectiveness in joint video and language understanding has not been widely
explored. In this paper, we aim to develop a novel multi-modal foundation model
capable of comprehending video, image, and language within a general framework.
To achieve this goal, we introduce Valley, a Video Assistant with Large
Language model Enhanced abilitY. The Valley consists of a LLM, a temporal
modeling module, a visual encoder, and a simple projection module designed to
bridge visual and textual modes. To empower Valley with video comprehension and
instruction-following capabilities, we construct a video instruction dataset
and adopt a two-stage tuning procedure to train it. Specifically, we employ
ChatGPT to facilitate the construction of task-oriented conversation data
encompassing various tasks, including multi-shot captions, long video
descriptions, action recognition, causal relationship inference, etc.
Subsequently, we adopt a pre-training-then-instructions-tuned pipeline to align
visual and textual modalities and improve the instruction-following capability
of Valley. Qualitative experiments demonstrate that Valley has the potential to
function as a highly effective video assistant that can make complex video
understanding scenarios easy
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