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.
The development of cellulose-based hydrogel has occupied a pivotal position in almost all walks of life. However, the native cellulose can not be directly used for preparing hydrogel due to the ...complex non-covalent interactions. Some literature has discussed the dissolution and modification of cellulose but has yet to address the influence of the pretreatment on the as-prepared hydrogels. Firstly, the "touching" of cellulose by derivative and non-derivative solvents was introduced, viz., the dissolution of cellulose. Secondly, the "conversion" of functional groups on the cellulose surface by special routes, viz., the modification of cellulose. The above-mentioned two parts were intended to explain the changes in physicochemical properties of cellulose by these routes and their influences on the subsequent hydrogel preparation. Finally, we summarized the "reinforcement" of cellulose-based hydrogels by physical and chemical techniques, viz., improving the mechanical properties of cellulose-based hydrogels and the changes in the multi-level structure of the interior of cellulose-based hydrogels.
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.
Self-healing hydrogels with pH-responsiveness could protect loaded drugs from being destroyed till it arrives to the target. The pectin-based hydrogel is a candidate due to the health benefit, ...anti-inflammation, antineoplastic activity, nontoxicity, and biospecific degradation, et al. However, the abundant existence of water-soluble branched heteropolysaccharide chains influenced its performance resulting in limitation of the potential. In the present study, we prepared a series of self-healing pectin/chitosan hydrogels via the Diels-Alder reaction. Moreover, pectin/chitosan composite hydrogel was prepared as a contrast. By comparison, it can be seen that the Diels-Alder reaction greatly improved the cross-linking density of hydrogels. The self-healing experiments showed excellent self-healing performance. In different swelling mediums, significant transformation in the swelling ratio was shown, indicating well-swelling property, pH- and thermo-responsiveness. The drug loading and release studies presented high loading efficiency and sustained release performance. The cytotoxicity assay that showed a high cell proliferation ratio manifested great cytocompatibility.
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•Diels-Alder reaction was firstly employed to prepare self-healing pectin/chitosan hydrogel.•The crosslinking density was mainly controlled by the Diels-Alder reaction.•The obtained hydrogel presented a high swelling ratio and pH-responsiveness.
L. is a widely cultivated herbal medicinal plant in China and other countries. In this study, two new 2, 3-dihydrobenzofuran glucosides (
,
) and fourteen known metabolites (
-
) were isolated from ...the stems and leaves of
(SLT). The chemical structures of the isolated compounds were characterized comprehensively based on one- and two-dimensional NMR spectroscopy and high resolution mass spectrometry. Absolute configurations of compounds
and
were determined by ECD calculations. Compounds
and
exhibited moderate in vitro inhibitory activities against human gastric cancer cell lines (AGS) with IC
values of 41.20 μmol/L and 30.43 μmol/L, respectively. The fingerprint profiles of stems and leaves of
with three color types of flowers (Janie Yellow Bright, Jinmen Orange, Shouyao Red and Yellow color) were established by high-performance liquid chromatography (HPLC). Ten different batches of stems and leaves were examined as follow: Shouyao Red and Yellow color (1, 2, 3), Janie Yellow Bright (4, 5, 6, 7) and Jinmen Orange (8, 9, 10). Twenty-two common peaks were identified with similarity values ranging from 0.910 to 0.977. Meanwhile, the average peak area of SLT in the three types of flowers was different and it was the highest in Janie Yellow Bright.
Purpose
Straw incorporation is an important management practice in global agriculture. However, present straw returning usually focus on returning straw into the topsoil, while neglecting the ...amendment of subsoil. The study aims to investigate the effect of different straw returning strategies on soil quality and wheat productivity, and to develop recommendations regarding sustainable agriculture.
Methods
A 2-year field experiment was conducted to evaluate the effects of five straw returning strategies on the soil quality and wheat yield in a winter wheat-summer maize cropping system in the North China Plain. Soil quality is defined as an index approach, including soil physical, chemical, and biological properties. The five treatments were straw removal (SR), straw mulching (SM), straw incorporation into topsoil (SI), deep-ploughing straw incorporation (DP-SI) and deep-injected straw incorporation (DI-SI).
Results
Our results showed that straw returning improved soil quality across 0–40 cm depth relative to SR. The DP-SI and DI-SI
a
(above straw cluster) significantly increased topsoil quality by 20.5–26.2% and 13.6–19.0% compared with SI and SM. The DI-SI
a
also enhanced the subsoil quality, which was characterized by a significant increase in soil nutrients, compared to other straw returning strategies. The soil quality of 0–40 cm layer under DP-SI and DI-SI was significantly higher than that of other treatments. In addition, a positive correlation between soil quality and wheat yield was observed. Thus, the higher soil quality under DP-SI and DI-SI improved the average wheat yield by 9.6% and 10.7% compared with SI, respectively.
Conclusion
These results indicates that DI-SI may improve subsoil properties and wheat yields and is likely an effective measure for sustainable development of a wheat-maize rotation system.
In order to further study the cushioning performance of concave hexagonal cores (CHCs) and expand their application range, the in-plane finite element model of CHCs is established in this paper. A ...dynamic cushioning coefficient method was proposed to characterize the cushioning performance of CHCs. The dynamic cushioning coefficient curve and minimum dynamic cushioning coefficient (MDCC) of CHCs with different impact velocities and structural parameters are obtained. The influence rules of structural parameters and impact velocities on the MDCC are analyzed; the deformation mode and transformation empirical formula are also obtained. The results show that when other parameters are constant, the MDCC of CHCs decreases with the increase of impact velocity, increases with the increase of wall thickness and side length ratio, and decreases with the increase of expansion angle. The theoretical analysis is consistent with the finite element results, which further verifies the reliability of the model. This paper provides a solid theoretical basis for the industrial application of the cushioning performance of CHCs and forms a key technical support.
Quantitative apparent diffusion coefficient (ADC) values of diffusion weighted imaging (DWI) could be applied to grade gliomas. This meta-analysis was conducted to assess the accuracy of ADC analysis ...in differentiating high-grade (HGGs) from low-grade gliomas (LGGs).
PubMed, Cochrane library, Science Direct, and Embase were searched to identify suitable studies up to September 1, 2018. The quality of studies was evaluated by the quality assessment of diagnostic accuracy studies (QUADAS 2). We estimated the pooled sensitivity, specificity, positive and negative likelihood ratios (LR), diagnostic accuracy ratio (DOR) with 95% confidence intervals (CI), and determined the accuracy of the data by using the summary receiver operating characteristic (SROC) and calculating the area under the curve (AUC) to identity the accuracy of ADC analysis in grading gliomas.
Eighteen studies including 1172 patients were included and analyzed. The pooled sensitivity, specificity, PLR, NLR, DOR, and AUC with 95% CIs of DWI with b values of 1000 s/mm for separating HGGs from LGGs were 0.81 (95% CI 0.75-0.86), 0.87 (95% CI 0.81-0.91), 6.1 (95% CI 4.2-8.9), 0.22 (95% CI 0.17-0.29), 28 (95% CI 17-45), and 0.91 (95% CI 0.88-0.93), respectively. DWI with b values of 3000 s/mm showed slightly higher accuracy than that of 1000 (sensitivity 0.80, specificity 0.90 and AUC 0.92). Meta-regression analyses showed that field strengths and b values had significant impacts on diagnostic efficacy. Deeks testing confirmed no significant publication bias in all studies.
This meta-analysis suggested that ADC analysis of DWI have high accuracy in differentiating HGGs from LGGs. Standardized methodology is warranted to guide the use of this technique for clinical decision-making.
Injectable hydrogels with self-healing ability present great potential for drug delivery. They could be facilely implanted in vivo and maintained structural and functional integrity till the hydrogel ...arriving at target sites. Herein, a series of injectable and self-healing composite hydrogel were developed as delivery vehicles for anti-cancer drug. The hydrogels were obtained with varying ratios of oxidized pectin/chitosan to nano γ-Fe2O3, which present excellent injectable, self-healing, magnetic, high biocompatible, and anti-cancer properties. The nano γ-Fe2O3 with particle size of about 0.25 μm loaded on the surface of hydrogel. Magnetic hysteresis loops of the hydrogel presented S-shape over the applied magnetics and the MS value was 4.86 emu/g. When pH dropped from 7.4 to 6.5 or temperature increased form 36 °C to 37 °C, the percentage increase in the swelling rate of OP4-400 reached to 35.89% and 25.13%, respectively. The composite hydrogels could continuously release water-soluble 5-FU for more than 12 h. In addition, the drug delivery systems indicated acceptable anti-cancer property though trace amounts of 5-FU were added in the hydrogel systems. The addition of γ-Fe2O3 could not only be beneficial to the targeting but also collectively enhance the anti-cancer property.
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•γ-Fe2O3 was firstly introduced into pectin/chitosan hydrogel to enhance anti-cancer properties.•Injectability and self-healing property of pectin/chitosan/γ-Fe2O3 hydrogel was firstly studied.•The hydrogels present high injectable, self-healing, pH- and thermo-sensitive performance.•The γ-Fe2O3 significantly enhanced the anti-cancer properties without decreasing biocompatibility.
SUMMARY
Malvids is one of the largest clades of rosids, includes 58 families and exhibits remarkable morphological and ecological diversity. Here, we report a high‐quality chromosome‐level genome ...assembly for Euscaphis japonica, an early‐diverging species within malvids. Genome‐based phylogenetic analysis suggests that the unstable phylogenetic position of E. japonica may result from incomplete lineage sorting and hybridization event during the diversification of the ancestral population of malvids. Euscaphis japonica experienced two polyploidization events: the ancient whole genome triplication event shared with most eudicots (commonly known as the γ event) and a more recent whole genome duplication event, unique to E. japonica. By resequencing 101 samples from 11 populations, we speculate that the temperature has led to the differentiation of the evergreen and deciduous of E. japonica and the completely different population histories of these two groups. In total, 1012 candidate positively selected genes in the evergreen were detected, some of which are involved in flower and fruit development. We found that reddening and dehiscence of the E. japonica pericarp and long fruit‐hanging time promoted the reproduction of E. japonica populations, and revealed the expression patterns of genes related to fruit reddening, dehiscence and abscission. The key genes involved in pentacyclic triterpene synthesis in E. japonica were identified, and different expression patterns of these genes may contribute to pentacyclic triterpene diversification. Our work sheds light on the evolution of E. japonica and malvids, particularly on the diversification of E. japonica and the genetic basis for their fruit dehiscence and abscission.
Significance Statement
Malvids is one of the largest clades of rosids and include 58 families, and its phylogenetic position is still contested. Euscaphis japonica, an early‐diverging species within malvids, is mainly distributed in Southeast Asia with deciduous or evergreen and two types: deciduous and evergreen. We assembled a high‐quality chromosome level genome of E. japonica, and found that E. japonica experienced a unique whole genome duplication event approximately 53 Mya. Genome‐based phylogenetic analysis suggests that the unstable phylogenetic position of E. japonica may result from incomplete lineage sorting and hybridization event during the diversification of the ancestral population of malvids. By resequencing 101 samples from 11 populations, we speculate that the temperature has led to the differentiation of the evergreen and deciduous of E. japonica and the completely different population histories of these two groups. Candidate positively selected genes related to the flower and fruit development in the evergreen were detected. We found that reddening and dehiscence of the E. japonica pericarp and long fruit‐hanging time promoted the reproduction of E. japonica populations, and revealed the expression patterns of genes related to fruit reddening, dehiscence, and abscission. The key genes involved in pentacyclic triterpene synthesis in E. japonica were identified, and different expression patterns of these genes may contribute to pentacyclic triterpene diversification. In summary, the present study has important scientific significance because it describes the phylogeny of the malvids, how the ancestor E. japonica differentiates into the evergreen and deciduous, and the evolutionary significance of the fruit.
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