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•Lycium barbarumpolysaccharide (LBP) has prebiotic properties and enhanced the growth of probiotic bacteria (L. acidophilus and B. longum) in vitro.•LBP could modulate the composition ...and enriched the beneficial species of gut microbiota.•LBP could enhance the host innate immune response and can increase the level of TGF-β and IL-6 in serum and sIgA in the colon.•LBP represents an attractive source of prebiotic nutraceuticals for the food and pharmaceutical industry.
The present study was done to evaluate the prebiotic effect of Lycium barbarum polysaccharide (LBP), its effect on murine fecal microbiota composition and innate immune response. Results showed that LBP supports the growth of selective probiotic bacteria with a maximum of 8.23 (log10 cfu/mL) and 6.62 (log10 cfu/mL) for Lactobacillus acidophilus and Bifidobacterium longum respectively. In vivo studies revealed that the administrations of LBP to mice resulted in an increase in the abundance of the phyla Proteobacteria and Firmicutes, while reducing the ratio of the phylum Bacteroidetes. At the genus level, the administration of LBP stimulated the emergence of some potential probiotic genera (Akkermansia, Lactobacillus, and Prevotellaceae). The concentrations of TGF-β and IL-6 in serum and sIgA in the colon content were enriched significantly after LBP administrations in mice. The thymus index and spleen index of mice treated with LBP displayed significant difference compared to the control group (P < 0.05). These findings suggest that LBP is a good source as a potential prebiotic and can enhance the intestinal microbiota and boost beneficial bacteria levels, modulate innate immune response.
Sulfide (H
S, HS
and S
) oxidation to sulfite and thiosulfate by heterotrophic bacteria, using sulfide:quinone oxidoreductase (SQR) and persulfide dioxygenase (PDO), has recently been reported as a ...possible detoxification mechanism for sulfide at high levels. Bioinformatic analysis revealed that the sqr and pdo genes were common in sequenced bacterial genomes, implying the sulfide oxidation may have other physiological functions. SQRs have previously been classified into six types. Here we grouped PDOs into three types and showed that some heterotrophic bacteria produced and released H
S from organic sulfur into the headspace during aerobic growth, and others, for example, Pseudomonas aeruginosa PAO1, with sqr and pdo did not release H
S. When the sqr and pdo genes were deleted, the mutants also released H
S. Both sulfide-oxidizing and non-oxidizing heterotrophic bacteria were readily isolated from various environmental samples. The sqr and pdo genes were also common in the published marine metagenomic and metatranscriptomic data, indicating that the genes are present and expressed. Thus, heterotrophic bacteria actively produce and consume sulfide when growing on organic compounds under aerobic conditions. Given their abundance on Earth, their contribution to the sulfur cycle should not be overlooked.
Exosomes are lipid bilayer membrane vesicles and are emerging as competent nanocarriers for drug delivery. The clinical translation of exosomes faces many challenges such as massive production, ...standard isolation, drug loading, stability and quality control. In recent years, artificial exosomes are emerging based on nanobiotechnology to overcome the limitations of natural exosomes. Major types of artificial exosomes include 'nanovesicles (NVs)', 'exosome-mimetic (EM)' and 'hybrid exosomes (HEs)', which are obtained by top-down, bottom-up and biohybrid strategies, respectively. Artificial exosomes are powerful alternatives to natural exosomes for drug delivery. Here, we outline recent advances in artificial exosomes through nanobiotechnology and discuss their strengths, limitations and future perspectives. The development of artificial exosomes holds great values for translational nanomedicine.
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•Bioapatite fossils were the main carriers of REY in the Tiki Basin.•The seawater was the main ore-forming fluid.•The average sedimentation rate calculated by the U-Th isotope of the ...sediments was 0.8 mm/Ka.
Deep-sea sediments in the eastern South Pacific Ocean were recently found to contain high concentrations of rare-earth elements and yttrium (REY). To understand the genesis of REY enrichment in the sediments, we performed detailed element and isotope geochemical analyses on samples from gravity core S028GC23 recovered from the Tiki Basin in the eastern South Pacific Ocean.
The REY-rich sediments in core S028GC23 are dark-brown to black zeolite clays, with REY (∑REY) contents of 1136–2213 ppm (average of 1857 ppm). The ∑REY contents in the sediments are positively correlated with P2O5 and negatively correlated with Ce anomalies. The REY-rich sediments display obvious Ce depletion and positive Y anomalies in the post-Archean Australian shale (PAAS)-normalized REY diagrams. Bioapatite fossils contain the highest REY concentrations (average of 8921 ppm) among the constituents, indicating that they are the primary hosts of REY. The REY enter through the roots and diffuse to the tops in the bioapatite fossils. Fe–Mn micronodules are divided into two different types based on Ce and Y anomalies in the PAAS-normalized REY patterns, and they have average REY concentrations of 781 ppm and 937 ppm, respectively. The phillipsite has low REY contents (average of 106 ppm) and is associated with a low sedimentation rate. REY patterns and Sr-Nd isotopic signatures show that seawater was the main ore-forming fluids during the formation of REY-rich sediments. The sedimentation rate of the sediments calculated by the 230Thex activities was 0.8 mm/Ka. The REY accumulation process can be explained by two-stage fluid-bioapatite fossil interactions and small contributions of Fe-Mn micronodules in an oxidized environment with slow sedimentation rate.
Background
Preoperative differentiation between malignant and benign soft‐tissue masses is important for treatment decisions.
Purpose/Hypothesis
To construct/validate a radiomics‐based machine method ...for differentiation between malignant and benign soft‐tissue masses.
Study Type
Retrospective.
Population
In all, 206 cases.
Field Strength/Sequence
The T1 sequence was acquired with the following range of parameters: relaxation time / echo time (TR/TE), 352–550/2.75–19 msec. The T2 sequence was acquired with the following parameters: TR/TE, 700–6370/40–120 msec. The data were divided into a 3.0T training cohort, a 1.5T MR validation cohort, and a 3.0T external validationcohort.
Assessment
Twelve machine‐learning methods were trained to establish classification models to predict the likelihood of malignancy of each lesion. The data of 206 cases were separated into a training set (n = 69) and two validation sets (n = 64, 73, respectively).
Statistical Tests
1) Demographic characteristics: a one‐way analysis of variance (ANOVA) test was performed for continuous variables as appropriate. The χ2 test or Fisher's exact test was performed for comparing categorical variables as appropriate. 2) The performance of four feature selection methods (least absolute shrinkage and selection operator LASSO, Boruta, Recursive feature elimination RFE, and minimum redundancy maximum relevance mRMR) and three classifiers (support vector machine SVM, generalized linear models GLM, and random forest RF) were compared for selecting the likelihood of malignancy of each lesion. The performance of the radiomics model was assessed using area under the receiver‐operating characteristic curve (AUC) and accuracy (ACC) values.
Results
The LASSO feature method + RF classifier achieved the highest AUC of 0.86 and 0.82 in the two validation cohorts. The nomogram achieved AUCs of 0.96 and 0.88, respectively, in the two validation sets, which was higher than that of the radiomic algorithm in the two validation sets and clinical model of the validation 1 set (0.92, 0.88 respectively). The accuracy, sensitivity, and specificity of the radiomics nomogram were 90.5%, 100%, and 80.6%, respectively, for validation set 1; and 80.8%, 75.8%, and 85.0% for validation set 2.
Data Conclusion
A machine‐learning nomogram based on radiomics was accurate for distinguishing between malignant and benign soft‐tissue masses.
Evidence Level
3
Technical Efficacy
Stage 2 J. Magn. Reson. Imaging 2020;52:873–882.
Triassic Xujiahe source rocks, the main gas source of shallow tight gas, are the most typical continental coal-bearing source rocks in the Sichuan Basin, South China. However, the organic matter ...enrichment section cannot be identified easily, leading to limited progress in the exploration of coal-bearing tight gas. This paper reveals the main controlling factors of the organic matter enrichment, reconstructs the evolution process of the Xujiahe palaeosedimentary environment, proposes a dynamic enrichment mechanism of the organic matter, and determines the organic matter enrichment section of the high-quality coal-bearing source rocks by geochemical characteristics of the source rocks, major elements, and trace elements. The results show that the Xujiahe sedimentary environment can be divided into a fluctuating stage of transitional sedimentation, stable stage of transitional sedimentation, fluctuating stage of continental sedimentation, and stable stage of continental sedimentation. The Xujiahe source rocks were featured with high-quality coal-bearing source rocks with high total organic carbon and maturity and good parent material in the stable stage of transitional sedimentation and fluctuating stage of continental sedimentation, in which the water was connected with the Palaeo-Tethys Ocean with abundant terrestrial organisms. The water was shallow in the fluctuating stage of transitional sedimentation with a low sedimentation rate, leading to poor organic matter enrichment. The Palaeo-Tethys Ocean withdrew westward from the Yangtze plate in the late period of the fluctuating stage of continental sedimentation, leading to the absence of algae and dinosteranes and a decrease in biological productivity in the stable stage of continental sedimentation. Therefore, high terrestrial inputs and biological productivity and high sedimentation rate were conducive to the organic matter preservation in the coal-bearing source rocks.
Trace metals play important roles in marine biogeochemical cycling processes. However, due to a lack of clean sampling techniques for trace metals, high quality data on the occurrence of dissolved ...trace metals in Chinese coastal seawaters are scarce. In this study, we used stringent trace-metal clean sampling and analytical techniques to investigate the spatial distributions of several dissolved trace metals (cadmium (Cd), cobalt (Co), copper (Cu), nickel (Ni), lead (Pb), silver (Ag), and zinc (Zn)) in Bohai Bay and Laizhou Bay, China. The dissolved metal concentrations in the southern Bohai Sea were comparable to those found in other bays or pristine coastal waters around the world. Metal concentrations were also determined at several nearshore sites, including rivers containing sewage discharges, a seaport, and the Yellow River. With the exception of the Yellow River, the metal concentrations at the nearshore sites were all elevated compared with those in the bays. The Cu speciation in the bay waters was also determined. Strong complexing ligands were found, often present as one class with logK=12.7–13.6, and the sources of the strong ligands could be attributed to either the river/sewage discharges or in situ production. Overall, the dissolved metal concentrations were not as high as expected even though the Bohai Sea is considered to be a heavily polluted inland sea. The low dissolved metal concentrations are in accordance with the relatively low metal concentrations in sediment in the bays, which may be due to the low flows of the rivers that enter the bays, resulting in the deposition of metals in riverbeds before they reach the bays.
•Spatial distribution of dissolved trace metals was investigated in the Bohai Sea.•Metal concentrations were higher in inshore sites compared with those in the bays.•Metal concentrations were low and comparable to those in pristine coastal waters.•Cu speciation was studied and strong complexing ligands were found in bay water.•The low metal concentrations in the bays may be due to reduced fluxes from rivers.
Tetrahydroprotoberberines (THPBs) are plant-specific alkaloids with significant medicinal value. They are present in trace amounts in plants and are difficult to chemically synthesize due to ...stereoselectivity and an unfavorable environment. In this study, a selective methylation strategy was developed for the biocatalysis of seven high-value-added THPB compounds using 4’-O-methyltransferase (Cj4’OMT), norcoclaurine 6-O-methyltransferase (Cj6OMT), and (S)-scoulerine 9-O-methyltransferase (SiSOMT and PsSOMT) in engineered E. coli. The methyltransferases Cj4’OMT, Cj6OMT, PsSOMT, and SiSOMT were expressed heterologously in E. coli. Compound 1 (10-methoxy-2,3,9-tetrahydroxyberbine) was synthesized using the recombinant E. coli strain Cj4’OMT and the substrate 2,3,9,10-tetrahydroxyberbine. Compound 2 (9-methoxy-2,3,10-tetrahydroxyberbine) was produced in the recombinant Escherichia coli (E. coli) strain PsSOMT, and compounds 2 and 3 (discretamine) were produced in the recombinant E. coli strain SiSOMT. Compounds 4 (9,10-methoxy-2,3-tetrahydroxyberbine) and 5 (corypalmine) were obtained by co-culturing the recombinant strains Cj4’OMT and SiSOMT with substrate. Compounds 6 (scoulerine) and 7 (isoscoulerine) were produced by co-culturing the substrate with the recombinant strains Cj4’OMT and Cj6OMT. To increase the yield of novel compound 2, the flask culture conditions of the engineered SiSOMT strain were optimized, resulting in the production of 165.74 mg/L of this compound. This study thus presents an enzymatic approach to the synthesis of high-value-added THPBs with minimum environmental wastage.
Sedimentary architecture dominated by transgression–regression cycles in the shallow Bohai shelf region contains information about global sea-level, climate and local tectonics. However, previous ...studies of transgression–regression cycles in this region at orbital timescales that extend back to the early Pleistocene are sparse, mainly because of the shortage of well-dated long cores. Although transgression–regression sedimentary cycles in the region have been interpreted in terms of local tectonics, sea-level, and climate change, the detailed structure of marine transgressions and their significance for Quaternary global sea-level variations remains to be examined. In this study, we present an integrated sedimentological, geochemical and paleontological study of a 212.4 m (∼1 Ma) core (BH08) recovered from the Bohai Sea, China, for which an astronomically-based age model is available. Correspondence between marine-terrestrial sedimentary cycles and global sea-level fluctuations suggests that stacking of marine and terrestrial sediments was driven mainly by glacio-eustatic sea-level fluctuations in a context in which tectonic subsidence was largely balanced by sediment supply over the last ∼1 Ma. We report a dominant 100-kyr cycle beginning at ∼650 ka, which reflects the worldwide influence of the mid-Pleistocene transition (MPT) in sea-level records. We find that neritic deposits after the MPT were relatively thicker than before the MPT, which indicates an important control of the MPT on sedimentary architecture through lengthening of the duration of sea-level highstands.
•Marine and terrestrial deposition alternated in the Bohai Sea over the last ∼1 Ma.•Sea-level changes governed the sedimentary architecture in the Bohai Sea.•The MPT influenced the deposition through modulating sea-level changes.
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