Abstract
Background
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel β-coronavirus, causes severe pneumonia and has spread throughout the globe rapidly. The disease associated ...with SARS-CoV-2 infection is named coronavirus disease 2019 (COVID-19). To date, real-time reverse-transcription polymerase chain reaction (RT-PCR) is the only test able to confirm this infection. However, the accuracy of RT-PCR depends on several factors; variations in these factors might significantly lower the sensitivity of detection.
Methods
In this study, we developed a peptide-based luminescent immunoassay that detected immunoglobulin (Ig)G and IgM. The assay cutoff value was determined by evaluating the sera from healthy and infected patients for pathogens other than SARS-CoV-2.
Results
To evaluate assay performance, we detected IgG and IgM in the sera from confirmed patients. The positive rate of IgG and IgM was 71.4% and 57.2%, respectively.
Conclusions
Therefore, combining our immunoassay with real-time RT-PCR might enhance the diagnostic accuracy of COVID-19.
A peptide-based magnetic chemiluminescence enzyme immunoassay for the detection of SARS-CoV-2 antibodies was developed; 71.4% (197 of 276) and 57.2% (158 of 276) of the COVID-19 inpatients were positive for IgG and IgM against SARS-CoV-2.
Cucurbitnurils (Qns or CBns), as a classical of artificial organic macrocyclic hosts, were found to have excellent advantages in the fabricating of tunable and smart organic luminescent ...materials in aqueous media and the solid state with high emitting efficiency under the rigid pumpkin-shaped structure-derived macrocyclic-confinement effect in recent years. This review aims to give a systematically up-to-date overview of the Qn-based supramolecular organic luminescent emissions from the confined spaces triggered host–guest complexes, including the assembly fashions and the mechanisms of the macrocycle-based luminescent complexes, as well as their applications. Finally, challenges and outlook are provided. Since this class of Qn-based supramolecular organic luminescent emissions, which have essentially derived from the cavity-dependent confinement effect and the resulting assembly fashions, emerged only a few years ago, we hope this review will provide valuable information for the further development of macrocycle-based light-emitting materials and other related research fields.
Porous materials, especially metal–organic frameworks, covalent organic frameworks, and supramolecular organic frameworks, are widely used in heterogeneous catalysis, adsorption, and ion exchange. ...Cucurbitnurils (Qns) suitable building units for porous materials because they possess cavities with neutral electrostatic potential, portal carbonyls with negative electrostatic potential, and outer surfaces with positive electrostatic potential, which may result in the formation of Qn‐based supramolecular frameworks (QSFs) assembled through the interaction of guests within Qns, the coordination of Qns with metal ions, and outer‐surface interaction of Qns (OSIQ). This review summarizes the various QSFs assembled via OSIQs. The QSFs can be classified as being assembled by 1) self‐induced OSIQ, 2) anion‐induced OSIQ, and 3) aromatic‐induced OSIQ. The design and construction of QSFs with novel structures and specific functional properties may establish a new research direction in Qn chemistry.
This review summarizes the outer‐surface interactions of cucurbitnurils (OSIQ) in various simple cucurbitnuril‐based supramolecular frameworks (QSFs) and QSFs assembled via self‐induced OSIQ, anion‐induced OSIQs, and aromatic‐induced OSIQs. The design and construction of QSFs with novel structures and specific functional properties establishes a new research direction in cucurbitnuril chemistry.
The clinical features and immune responses of asymptomatic individuals infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have not been well described. We studied 37 ...asymptomatic individuals in the Wanzhou District who were diagnosed with RT-PCR-confirmed SARS-CoV-2 infections but without any relevant clinical symptoms in the preceding 14 d and during hospitalization. Asymptomatic individuals were admitted to the government-designated Wanzhou People's Hospital for centralized isolation in accordance with policy
. The median duration of viral shedding in the asymptomatic group was 19 d (interquartile range (IQR), 15-26 d). The asymptomatic group had a significantly longer duration of viral shedding than the symptomatic group (log-rank P = 0.028). The virus-specific IgG levels in the asymptomatic group (median S/CO, 3.4; IQR, 1.6-10.7) were significantly lower (P = 0.005) relative to the symptomatic group (median S/CO, 20.5; IQR, 5.8-38.2) in the acute phase. Of asymptomatic individuals, 93.3% (28/30) and 81.1% (30/37) had reduction in IgG and neutralizing antibody levels, respectively, during the early convalescent phase, as compared to 96.8% (30/31) and 62.2% (23/37) of symptomatic patients. Forty percent of asymptomatic individuals became seronegative and 12.9% of the symptomatic group became negative for IgG in the early convalescent phase. In addition, asymptomatic individuals exhibited lower levels of 18 pro- and anti-inflammatory cytokines. These data suggest that asymptomatic individuals had a weaker immune response to SARS-CoV-2 infection. The reduction in IgG and neutralizing antibody levels in the early convalescent phase might have implications for immunity strategy and serological surveys.
Adsorptive separation of olefin/paraffin mixtures by porous solids can greatly reduce the energy consumption associated with the currently employed cryogenic distillation technique. Here, the ...complete separation of propane and propylene by a designer microporous metal–organic framework material is reported. The compound, Y6(OH)8(abtc)3(H2O)6(DMA)2 (Y‐abtc, abtc = 3,3′,5,5′‐azobenzene‐tetracarboxylates; DMA = dimethylammonium), is rationally designed through topology‐guided replacement of inorganic building units. Y‐abtc is both thermally and hydrothermally robust, and possesses optimal pore window size for propane/propylene separation. It adsorbs propylene with fast kinetics under ambient temperature and pressure, but fully excludes propane, as a result of selective size exclusion. Multicomponent column breakthrough experiments confirm that polymer‐grade propylene (99.5%) can be obtained by this process, demonstrating its true potential as an alternative sorbent for efficient separation of propane/propylene mixtures.
A tailor‐made microporous metal–organic framework designed through a topologically guided secondary building unit (SBU) replacement strategy exhibits the highest selectivity for fast and efficient separation of propane and propylene via a size‐exclusion adsorption mechanism. This material, with excellent thermal and hydrothermal stability, and facile and scalable synthesis, is capable of producing polymer‐grade propylene (99.5%) from a typical propane/propylene mixture of cracking products.
Supramolecular architectures and materials have attracted immense attention during the last decades because they not only open the possibility of obtaining a large variety of aesthetically ...interesting structures but also have applications in gas storage, sensors, separation, catalysis, and so on. On the other hand, cucurbitnurils (Qns), a relatively new class of macrocyclic hosts with a rigid hydrophobic cavity and two identical carbonyl fringed portals, have attracted much attention in supramolecular chemistry. Because of the strong charge–dipole and hydrogen bonding interactions, as well as hydrophobic and hydrophilic effect derived from the negative portals and rigid cavities of Qns, nearly all research in Qns has been focused on utilizing the portals and cavities to construct supramolecular assemblies similar to other macrocyclic receptors such as cyclodextrin and calixarenes. Interestingly, a recent study revealed that other weak noncovalent interactions such as hydrogen bonding and π···π stacking, as well as C–H···π and ion–dipole interactions, could also be defined as “outer-surface interactions”, which are derived from the electrostatically positive outer surface of Qns. These interactions could be the driving forces in the formation of various novel Qn-based supramolecular architectures and functional materials. In this Account, we provide a comprehensive overview of supramolecular self-assemblies based on the outer-surface interactions of Qns. These outer-surface interactions include those between Qns, Qns and aromatic molecules, Qns and calixarenes, Qns and inorganic complex ions, and Qns and polyoxometalates. Pioneering work has shown that such weak noncovalent interactions play very important roles in the formation of various Qn-based functional materials and supramolecular architectures. For example, hydrogen bonds in outer-surface interactions between Qn molecules not only function as the sole driving force in the formation of one-dimensional Qn porous channels but also assist the bonding forces of the channels in capturing and accommodating acetylene molecules and carbon dioxide in the channel cavities. Moreover, upon introduction of a third species such as an aromatic molecule or inorganic anion into the Qn/metal system, “outer-surface interactions” could lead to Qn/metal-based self-assemblies from simple finite supramolecular coordination complexes to infinite polydimensional supramolecular architectures and other structures. Overall, this Account focuses on the novel self-assembly driving force derived from Qns including (i) concepts of the outer-surface interactions of Qns, (ii) providing plausible explanations of the mechanisms of the outer-surface interactions of Qns, and (iii) introduction of an overview of the developments and practical applications of outer-surface interactions of Qns in supramolecular chemistry. It is hoped that this study based on the outer-surface interactions of Qns can enrich the field of molecular engineering of functional supramolecular systems and provide new opportunities for the construction of functional materials and architectures.
In this work, surfactant-free atomically ultrathin Rh nanosheet nanoassemblies (Rh NNs) are synthesized and used for the first time as an effective electrocatalyst in the nitrogen reduction reaction ...(NRR) at ambient temperature and pressure. The inorganic polymer RhCl
3
–K
3
Co(CN)
6
cyanogel plays an important role in the generation of ultrathin Rh nanosheets with a clean surface. Due to their unique ultrathin two-dimensional nanosheet structure (
ca.
1 nm) with a high specific surface area and modified electronic structure, the surfactant-free Rh NNs demonstrate an excellent catalytic activity for the NRR with a high production yield (NH
3
: 23.88 μg h
−1
mg
cat
−1
) and favorable selectivity (no N
2
H
4
generation) at low potential (−0.2 V
vs.
RHE), outperforming most of the current electrocatalysts reported for the NRR. Except the contribution to the efficient NRR electrocatalysis, this synthesis strategy would provide some new insights into the preparation of ultrathin precious metal nanosheets for energy related applications.
Accumulating evidence suggests that Ras GTPase‐activating protein SH3 domain‐binding protein 1 (G3BP1) is very crucial to regulate tumorigenesis and metastasis. Recently, many research works have ...suggested that G3BP1 is overexpressed in many human cancers including esophageal cancer. Nevertheless, the functional roles of G3BP1 in esophageal cancer are still unknown. Here, the results suggested that silencing of G3BP1 inhibited proliferation, migration, and invasion of esophageal cancer cells, whereas overexpression of G3BP1 led to opposite effects on the growth and metastasis. Surprisingly, G3BP1‐depletion had no effect on cell death but caused the arrest of cell cycle in the G0/G1 phase and increased the levels of p53 and p21. In addition, loss of G3BP1 led to a significant elevation of E‐cadherin and decrease of N‐cadherin, Vimentin, Snail, MMP‐9, and MMP‐2. Mechanistically, loss of G3BP1 dramatically suppressed Wnt‐stimulated T‐cell factor/lymphoid enhancer factor (TCF/LEF) transcription factor activity and downregulated its target genes including c‐Myc, Axin2, and cyclin D1. Moreover, knockdown of G3BP1 downregulated the expression levels of p‐PI3K, p‐AKT, and p‐GSK‐3β, but the total PI3K, AKT, and GSK‐3β were not changed. Furthermore, our data proved that the promoting effects of G3BP1‐overexpression on cell proliferation, migration, and invasion could be rescued by PI3K inhibitor LY294002 treatment. Collectively, our results here elucidate that G3BP1‐depletion suppresses proliferation, migration, and invasion capabilities of esophageal cancer cells via the inactivation of Wnt/β‐catenin and PI3K/AKT signaling pathways. Furthermore, our findings imply that G3BP1 can participate in the regulation of esophageal cancer progression, and will be taken as a promising target to treat esophageal cancer.
In our study, we investigated the effects of GTPase‐activating protein SH3 domain‐binding protein 1‐depletion (G3BP1) on cell proliferation, cell cycle, cell death, migration, and invasion of esophageal cancer cells. Our results demonstrated that knockdown of G3BP1 gave rise to inhibition of esophageal cancer cell proliferation, migration, invasion, epithelial‐mesenchymal transition, and cell cycle arrest in the G0/G1 phase through suppressing Wnt/β‐catenin and PI3K/AKT signaling pathways, whereas overexpression of G3BP1 led to opposite the effects on proliferation, migration, and invasion. Our data suggest that G3BP1 plays a crucial role in esophageal cancer progression, and may be a novel prognostic marker and potential therapeutic target for esophageal cancer.
Biodegradable materials for bone defect repair Wei, Shuai; Ma, Jian-Xiong; Xu, Lai ...
Military Medical Research/Military medical research,
11/2020, Letnik:
7, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Compared with non-degradable materials, biodegradable biomaterials play an increasingly important role in the repairing of severe bone defects, and have attracted extensive attention from ...researchers. In the treatment of bone defects, scaffolds made of biodegradable materials can provide a crawling bridge for new bone tissue in the gap and a platform for cells and growth factors to play a physiological role, which will eventually be degraded and absorbed in the body and be replaced by the new bone tissue. Traditional biodegradable materials include polymers, ceramics and metals, which have been used in bone defect repairing for many years. Although these materials have more or fewer shortcomings, they are still the cornerstone of our development of a new generation of degradable materials. With the rapid development of modern science and technology, in the twenty-first century, more and more kinds of new biodegradable materials emerge in endlessly, such as new intelligent micro-nano materials and cell-based products. At the same time, there are many new fabrication technologies of improving biodegradable materials, such as modular fabrication, 3D and 4D printing, interface reinforcement and nanotechnology. This review will introduce various kinds of biodegradable materials commonly used in bone defect repairing, especially the newly emerging materials and their fabrication technology in recent years, and look forward to the future research direction, hoping to provide researchers in the field with some inspiration and reference.
We report acute antibody responses to SARS-CoV-2 in 285 patients with COVID-19. Within 19 days after symptom onset, 100% of patients tested positive for antiviral immunoglobulin-G (IgG). ...Seroconversion for IgG and IgM occurred simultaneously or sequentially. Both IgG and IgM titers plateaued within 6 days after seroconversion. Serological testing may be helpful for the diagnosis of suspected patients with negative RT-PCR results and for the identification of asymptomatic infections.
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