The ongoing worldwide SARS-CoV-2 epidemic clearly has a tremendous influence on public health. Molecular detection based on oral swabs was used for confirmation of SARS-CoV-2 infection. However, high ...false negative rates were reported. We describe here the development of a point-of-care (POC) serological assay for the detection of IgG antibody against SARS-CoV-2. The principle of a lateral flow immunoassay strip (LFIAs) consists of fixing SARS-CoV-2 nucleocapsid protein to the surface of the strip and coupling anti-human IgG with colloidal gold nanoparticles (Au NPs). A series of parameters of this method were optimized, including the concentration of coating antigen, BSA blocking concentration and pH value for conjugation. The entire detection process took 15-20 min with a volume of 80 μL of the analyte solution containing 10 μL of serum and 70 μL sample diluent. The performance of the established assay was evaluated using serum samples of the clinically diagnosed cases of Coronavirus Disease 2019 (COVID-19). Our results indicated that the LFIAs for SARS-CoV-2 had satisfactory stability and reproducibility. As a result, our fast and easy LFIAs could provide a preliminary test result for physicians to make the correct diagnosis of SARS-CoV-2 infections along with alternative testing methods and clinical findings, as well as seroprevalence determination, especially in low-resource countries.
Rapid and simple LFIA strips based on Au NPs provide a preliminary test result for physicians to make the correct diagnosis of SARS-CoV-2 infections along with alternative testing methods.
Last year, the novel coronavirus
disease (COVID-19) emerged in
Wuhan, and it has rapidly spread to many other countries and regions.
COVID-19 exhibits a strong human-to-human transmission infectivity
...and could cause acute respiratory diseases. Asymptomatic carriers
are able to infect other healthy persons, and this poses a challenge
for public health; the World Health Organization (WHO) has already
announced COVID-19 as a global pandemic. Nucleic acid testing, considered
as the current primary method for diagnosing COVID-19, might lead
to false negatives and is difficult to be applied for every suspected
patient because of the existence of asymptomatic carriers. Meanwhile,
detecting specific antibodies in blood, such as the IgM antibody,
against the SARS-CoV-2 virus is another choice for COVID-19 diagnosis,
as it is widely accepted that IgM is an important indicator in the
acute infection period. In this study, a colloidal gold nanoparticle-based
lateral-flow (AuNP-LF) assay was developed to achieve rapid diagnosis
and on-site detection of the IgM antibody against the SARS-CoV-2 virus
through the indirect immunochromatography method. For preparing AuNP-LF
strips, the SARS-CoV-2 nucleoprotein (SARS-CoV-2 NP) was coated on
an analytical membrane for sample capture, and antihuman IgM was conjugated
with AuNPs to form the detecting reporter. Optimization of AuNP-LF
assay was carried out by altering the pH value and the amount of antihuman
IgM. The performance of AuNP-LF assay was evaluated by testing serum
samples of COVID-19 patients and normal humans. The results were compared
with the real-time polymerase chain reaction. The sensitivity and
specificity of AuNP-LF assay were determined to be 100 and 93.3%,
respectively, and an almost perfect agreement was exhibited by Kappa
statistics (κ coefficient = 0.872). AuNP-LF assay showed outstanding
selectivity in the detection of IgM against the SARS-CoV-2 virus with
no interference from other viruses such as severe fever with thrombocytopenia
syndrome virus (SFTSV) and dengue virus (DFV). AuNP-LF assay was able
to achieve results within 15 min and needed only 10–20 μL
serum for each test. As a whole, in the light of its advantages such
as excellent specificity and stability, easy operation, low cost,
and being less time-consuming, AuNP-LF assay is a feasible method
for the diagnosis of COVID-19 in primary hospitals and laboratories,
especially in emergency situations in which numerous samples need
to be tested on time.
The emergence of high-entropy materials has inspired the exploration of novel materials in diverse technologies. In electrochemical energy storage, high-entropy design has shown advantageous impacts ...on battery materials such as suppressing undesired short-range order, frustrating energy landscape, decreasing volumetric change and reducing the reliance on critical metals. This comment addresses the definition and potential improper use of the term “high entropy” in the context of battery materials design, highlights the unique properties of high-entropy materials in battery applications, and outlines the remaining challenges in the synthesis, characterization, and computational modeling of high-entropy battery materials.
We present an analysis of local molecular clouds ( km s−1, i.e., <1.5 kpc) in the first Galactic quadrant ( and ), a pilot region of the Milky Way Imaging Scroll Painting (MWISP) CO survey. Using the ...Spectral Clustering for Interstellar Molecular Emission Segmentation algorithm to divide large molecular clouds into moderate-size ones, we determined distances to 28 molecular clouds with the background-eliminated extinction-parallax method using the Gaia DR2 parallax measurements aided by AG and AV; the distance ranges from 250 to about 1.5 kpc. These incomplete distance samples indicate a linear relationship between the distance and the radial velocity (VLSR) with a scatter of 0.16 kpc, and kinematic distances may be systematically larger for local molecular clouds. In order to investigate fundamental properties of molecular clouds, such as the total sample number, the line width, the brightness temperature, the physical area, and the mass, we decompose the spectral cube using the density-based spatial clustering of applications with noise (DBSCAN) algorithm. Post-selection criteria are imposed on DBSCAN clusters to remove the noise contamination, and we found that the separation of molecular cloud individuals is reliable based on a definition of independent consecutive structures in l-b-V space. The completeness of the local molecular cloud flux collected by the MWISP CO survey is about 80%. The physical area, A, shows a power-law distribution, dN/d , while the molecular cloud mass also follows a power-law distribution but is slightly flatter, dN/dM ∝ M−1.96 0.11.
The microbial colonization profiles on microplastics (MPs) in marine environments have recently sparked global interest. However, many studies have characterized plastisphere microbiomes without ...considering the ecological processes that underly microbiome assembly. Here, we carried out a three-timepoint exposure experiment at 1-, 4-, and 8-week and investigated the colonization dynamics for polyethylene, polypropylene, polystyrene, polyvinyl chloride, and acrylonitrile-butadiene-styrene MP pellets in natural coastal water. Using high-throughput sequencing of 16S rRNA, we found diversity and evenness were higher (p < 0.05) in the plastisphere communities than those in seawater, and microorganisms colonizing were co-influenced by environmental factors, polymer types, and exposure duration. Functional potential and co-occurrence network analysis revealed that MP exposure enriched the xenobiotic biodegradation potential and reduced the complexity of the MP microbial network. Simultaneously, null-model analyses indicated that stochastic processes contributed a bigger role than deterministic processes in shaping plastisphere microbial community structure with dispersal limitations contributing to a greater extent to microbial succession trajectories. These results implied the plastic surface had a more important role as a raft onto which microbes attach rather than selectively recruiting plastic-specific microbial colonizers. Our work strengthened the understanding of the ecological mechanisms by which microbial community patterns are controlled during colonization by plastic-associated microbes.
Display omitted
•Microorganisms colonizing microplastics (MPS) were co-influenced by multiply factors.•MPs exposure enriched the microbial xenobiotic biodegradation potential.•MPs exposure reduced the complexity of the plastisphere microbial community network.•Plastisphere microbial trajectory was mainly governed by stochastic process.•MPs had limit role to selectively recruiting plastic-specific microbial colonizers.
Primary angle closure glaucoma (PACG) is higher in Asians than Europeans and Africans, with over 80% of PACG worldwide in Asia. Previous estimates of PACG were based largely on early studies, mostly ...using inappropriate case definitions. Therefore, we did a systematic review and meta-analysis to estimate the prevalence of PACG in adult Asian populations and to quantify its association with age, gender, and region.
All primary reports of population-based studies that reported the prevalence of PACG in adult Asian populations were identified. PACG case definition was compatible with the ISGEO definition. Twenty-nine population-based studies were included. The overall pooled prevalence estimates were calculated using a random effect model, and ethnicity-, age- and gender-specific pooled prevalence estimates were also calculated.
The overall pooled prevalence of PACG in those of adult Asians was 0.75% (95% CI, 0.58, 0.96). Ethnicity-specific pooled prevalence estimates were 0.97% (0.22, 4.27) in Middle East group, 0.66% (0.23, 1.86) in South East Asia group, 0.46% (0.32, 0.64) in India group, 1.10% (0.85, 1.44) in China group, and 1.19% (0.35, 3.98) in Japan group, respectively. Age-specific prevalence was 0.21% (0.12, 0.37) for those 40-49 years, 0.54% (0.34, 0.85) for those 50-59 years, 1.26% (0.93, 1.71) for those 60-69 years, and 2.32% (1.74, 3.08) for those 70 years or above. The overall female to male ratio of the PACG prevalence was 1.51∶1 (95% CI 1.01, 2.28).
PACG affects approximately 0.75% adult Asians, increasing double per decade, and 60% of cases being female. The prevalence rates vary greatly by ethnic region.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Self-interacting multistate boson stars Li, Hong-Bo; Zeng, Yan-Bo; Song, Yan ...
The journal of high energy physics,
04/2021, Letnik:
2021, Številka:
4
Journal Article
Recenzirano
Odprti dostop
A
bstract
In this paper, we consider rotating multistate boson stars with quartic self-interactions. In contrast to the nodeless quartic-boson stars in 1, the self-interacting multistate boson stars ...(SIMBSs) have two types of nodes, including the
1
S
2
S
and
1
S
2
P
states. We show the mass
M
of SIMBSs as a function of the synchronized frequency
ω
, and the nonsynchronized frequency
ω
2
for three different cases. Moreover, for the case of two coexisting states with self-interacting potential, we study the mass
M
of SIMBSs versus the angular momentum
J
for the synchronized frequency
ω
and the nonsynchronized frequency
ω
2
. Furthermore, for three different cases, we analyze the coexisting phase with both the ground and first excited states for SIMBSs. We also calculate the maximum value of coupling parameter Λ, and find the coupling parameter Λ exists the finite range.
Using a wet chemical process, a continuous network of silver nanowires was buried at the surface of a transparent polymer (PVA) to form a flexible transparent conductor, which shows high optical ...transparency, low sheet resistance, a smooth surface, and superior mechanical, thermal and chemical stabilities. The composite is a competitive choice for transparent electrodes in OLED and thin film solar cells.
Although various types of drugs and therapies are available to treat atherosclerosis, it remains a major cause of mortality throughout the world. Macrophages are the major source of foam cells, which ...are hallmarks of atherosclerotic lesions. Consequently, the roles of macrophages in the pathophysiology of atherosclerosis are increasingly investigated. Autophagy is a self-protecting cellular catabolic pathway. Since its discovery, autophagy has been found to be associated with a variety of diseases, including cardiovascular diseases, malignant tumors, neurodegenerative diseases, and immune system disorders. Accumulating evidence demonstrates that autophagy plays an important role in inhibiting inflammation and apoptosis, and in promoting efferocytosis and cholesterol efflux. These facts sug- gest the induction of autophagy may be exploited as a potential strategy for the treatment of atherosclerosis. In this review we mainly discuss the relationship between macrophage autophagy and atherosclerosis and the molecular mechanisms, as well as the recent advances in targeting the process of autophagy to treat atherosclerosis.
The molecular mechanism underlying brain regeneration in vertebrates remains elusive. We performed spatial enhanced resolution omics sequencing (Stereo-seq) to capture spatially resolved single-cell ...transcriptomes of axolotl telencephalon sections during development and regeneration. Annotated cell types exhibited distinct spatial distribution, molecular features, and functions. We identified an injury-induced ependymoglial cell cluster at the wound site as a progenitor cell population for the potential replenishment of lost neurons, through a cell state transition process resembling neurogenesis during development. Transcriptome comparisons indicated that these induced cells may originate from local resident ependymoglial cells. We further uncovered spatially defined neurons at the lesion site that may regress to an immature neuron–like state. Our work establishes spatial transcriptome profiles of an anamniote tetrapod brain and decodes potential neurogenesis from ependymoglial cells for development and regeneration, thus providing mechanistic insights into vertebrate brain regeneration.
Trade-offs in brain development
Salamander brains share some, but not all, structures with the mammalian brain. They also have greater capacity to regenerate in response to damage. Three groups now come together with single-cell transcriptomics analyses that set the salamander brain in evolutionary context (see the Perspective by Faltine-Gonzalez and Kebschull). By comparing salamander brains with those of lizard, turtle, and mouse, Woych
et al
. track the evolutionary innovations that gave rise to the mammalian six-layered neocortex, which salamanders do not have. Lust
et al
. take a close look at why the axolotl brain is so much more capable of regeneration than is the mammalian brain. Finally, Wei
et al
. compare the developmental and regenerative processes in the axolotl brain. —PJH
Developmental and regenerative processes in the axolotl brain are revealed by single-cell analyses.
INTRODUCTION
Brain regeneration requires the coordination of complex responses in a time- and region-specific manner. Identifying the cell types and molecules involved in this process would advance our understanding of brain regeneration and provide potential targets for regenerative medicine research. However, progress in this field has been hampered by the limited regeneration capacity of the mammalian brain and an incomplete mechanistic understanding of the regeneration process at both the cellular and molecular levels. Axolotls (
Ambystoma mexicanum
) can regenerate damaged appendages and multiple internal organs, including the brain. Therefore, axolotls may serve as a model for studying brain regeneration.
RATIONALE
If we are to understand the mechanism of brain regeneration, we need research tools that can achieve large-scale data acquisition and analyses to simultaneously decode complex cellular and molecular responses. It also seemed to us that a comparison between brain regeneration and developmental processes would help to provide new insights into the nature of brain regeneration. Accordingly, we removed a small portion of the lateral pallium region of the axolotl left telencephalon and collected tissue samples at multiple stages during regeneration. In parallel, we collected tissue samples of the axolotl telencephalon at multiple developmental stages. We then used high-definition and large-field Stereo-seq (spatial enhanced resolution omics sequencing) technology to generate spatial transcriptomic data from sections that covered both hemispheres of the axolotl telencephalon at single-cell resolution. Analyses of cell type annotation, cell spatial organization, gene activity dynamics, and cell state transition were performed for a mechanistic investigation of injury-induced regeneration compared to these cell attributes during development.
RESULTS
With the use of Stereo-seq, we generated a group of spatial transcriptomic data of telencephalon sections that covered six developmental and seven injury-induced regenerative stages. The data at single-cell resolution enabled us to identify 33 cell types present during development and 28 cell types involved in regeneration, including different types of excitatory and inhibitory neurons, and several ependymoglial cell subtypes. For development, our data revealed a primitive type of ependymoglial cells that may give rise to three subgroups of adult ependymoglial cells localized in separate areas of the ventricular zone, with different molecular features and potentially different functions. For regeneration, we discovered a subpopulation of ependymoglial cells that may originate from local resident ependymoglial cells activated by injury. This population of progenitor cells may then proliferate to cover the wound area and subsequently replenish lost neurons through a state transition to intermediate progenitors, immature neurons, and eventually mature neurons. When comparing cellular and molecular dynamics of the axolotl telencephalon between development and regeneration, we found that injury-induced ependymoglial cells were similar to developmental-specific ependymoglial cells in terms of their transcriptome state. We also observed that regeneration of the axolotl telencephalon exhibited neurogenesis patterns similar to those seen in development in molecular cascades and the potential cell lineage transition, which suggests that brain regeneration partially recapitulates the development process.
CONCLUSION
Our spatial transcriptomic data highlight the cellular and molecular features of the axolotl telencephalon during development and injury-induced regeneration. Further characterization of the activation and functional regulation of ependymoglial cells may yield insights for improving the regenerative capability of mammalian brains. Our single-cell spatial transcriptome of the axolotl telencephalon, a tetrapod vertebrate, also provides data useful for further research in developmental, regenerative, and evolutionary brain biology. All data are accessible in an interactive database (
https://db.cngb.org/stomics/artista
).
Development and regeneration of axolotl telencephalon.
The spatially resolved single-cell transcriptome of the adult axolotl telencephalon as determined by Stereo-seq analyses (left). Upon brain injury in the highlighted lateral pallium region of the left hemisphere, a neural progenitor subpopulation at the wound site was rapidly induced and subsequently replenished lost neurons (bottom right) through a process that partially resembles neurogenesis during development (top right).
CREDIT: YUNZHI YANG, BGI
PDF
