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Raising attentions have focused on how to alleviate greenhouse gas (GHG) emissions from orchard system while simultaneously increase fruit production. Microalgae-based biofertilizer represents a promising resource for improving soil fertility and higher productivity. However, the effects of microalgae application more especially live microalgae on GHG emissions are understudied. In this study, fruit yield and quality, GHG emissions, as well as soil organic carbon and nitrogen fractions were examined in a hawthorn orchard, under the effects of live microalgae-based biofertilizer applied at three doses and two modes. Compared with conventional fertilization, microalgae improved hawthorn yield by 15.7%−29.6% with a maximal increment at medium dose by root application, and significantly increased soluble and reducing sugars contents at high dose. While microalgae did not increase GHG emissions except for nitrous oxide at high dose by root application, instead it significantly increased methane uptake by 1.5−2.3 times in root application. In addition, microalgae showed an increasing trend in soil organic carbon content, and significantly increased the contents of soil dissolved organic carbon and microbial biomass carbon, as well as soil ammonium nitrogen and dissolved organic nitrogen at medium dose with root application. Overall, the results indicated that the live microalgae could be used as a green biofertilizer for improving fruit yield without increasing GHG emissions intensity and the comprehensive greenhouse effect, in particular at medium dose with root application. We presume that if lowering chemical fertilizer rates, application of the live microalgae-based biofertilizer may help to reduce nitrous oxide emissions without compromising fruit yield and quality. [ABSTRACT FROM AUTHOR]

Neurons within the pre-Bötzinger complex have been found experimentally to exhibit different firing activities. Mixed bursting is a special firing activities which has been found in neuron model and biological experiments. The traditional fast and slow dynamics analysis method encounters some difficulties in analyzing mixed bursting. Therefore, how to analyze the dynamic mechanism of mixed bursting generation and transition is a very important issue. In this paper, based on fast-slow decomposition, multiple timescale dynamics and one- and two-parameter bifurcation analysis, we investigate the mixed bursting and their transition mechanisms in pre-Bötzinger complex neurons. The results show that the generation mechanism of the mixed bursting is related to the multiple timescale of the neuron model. The results obtained in this paper is instructive for further understanding the dynamical behaviours and generation mechanisms of complex firing activities in biological nervous systems. [ABSTRACT FROM AUTHOR]

Bone metastasis is of common occurrence in renal cell carcinoma with poor prognosis, but no optimal treatment approach has been established for bone metastatic renal cell carcinoma. To explore the potential therapeutic targets for bone metastatic renal cell carcinoma, we profile single cell transcriptomes of 6 primary renal cell carcinoma and 9 bone metastatic renal cell carcinoma. We also include scRNA-seq data of early-stage renal cell carcinoma, late-stage renal cell carcinoma, normal kidneys and healthy bone marrow samples in the study to better understand the bone metastasis niche. The molecular properties and dynamic changes of major cell lineages in bone metastatic environment of renal cell carcinoma are characterized. Bone metastatic renal cell carcinoma is associated with multifaceted immune deficiency together with cancer-associated fibroblasts, specifically appearance of macrophages exhibiting malignant and pro-angiogenic features. We also reveal the dominance of immune inhibitory T cells in the bone metastatic renal cell carcinoma which can be partially restored by the treatment. Trajectory analysis showes that myeloid-derived suppressor cells are progenitors of macrophages in the bone metastatic renal cell carcinoma while monocytes are their progenitors in primary tumors and healthy bone marrows. Additionally, the infiltration of immune inhibitory CD47+ T cells is observed in bone metastatic tumors, which may be a result of reduced phagocytosis by SIRPA-expressing macrophages in the bone microenvironment. Together, our results provide a systematic view of various cell types in bone metastatic renal cell carcinoma and suggest avenues for therapeutic solutions. Single-cell profiling of primary and bone metastatic renal cell carcinoma suggests variation in intratumoral heterogeneity between samples and the is a valuable resource for examining the underlying pathogenic mechanisms for these cancers. [ABSTRACT FROM AUTHOR]

Anionocages have been developed as a unique family of hydrogen bonded cages. However, strategies for constructing anionocages are mainly limited to that based on (PO43−)‐bisurea coordination, neither the ligands nor the anions lack the simplicity and diversity of the maturely developed analogues based on metal coordination (i.e. metallocage). We report herein a more simple strategy for anionocages design based on (RPO32−)‐monourea coordination, utilizing monourea rather than bisurea as the hydrogen binding donor, and RPO32− rather than PO43− as the acceptor. Two fluorescent, quadruple helicate anionocages were constructed by a bis‐monourea ligand, and dianions PhOPO32− (H1) or HOPO32− (H1A), respectively, which were capable of encapsulating a series of cation guests. As revealed by molecular modeling, H1 features remarkable guest‐adaptive cavity breathing without change of the quadruple helicate topology, which allowed the encapsulation of different sized guests in an "induced fit" manner. [ABSTRACT FROM AUTHOR]

Anionocages have been developed as a unique family of hydrogen bonded cages. However, strategies for constructing anionocages are mainly limited to that based on (PO43−)‐bisurea coordination, neither the ligands nor the anions lack the simplicity and diversity of the maturely developed analogues based on metal coordination (i.e. metallocage). We report herein a more simple strategy for anionocages design based on (RPO32−)‐monourea coordination, utilizing monourea rather than bisurea as the hydrogen binding donor, and RPO32− rather than PO43− as the acceptor. Two fluorescent, quadruple helicate anionocages were constructed by a bis‐monourea ligand, and dianions PhOPO32− (H1) or HOPO32− (H1A), respectively, which were capable of encapsulating a series of cation guests. As revealed by molecular modeling, H1 features remarkable guest‐adaptive cavity breathing without change of the quadruple helicate topology, which allowed the encapsulation of different sized guests in an "induced fit" manner. [ABSTRACT FROM AUTHOR]

Biodegradable polymer blends filled with rod-like polysaccharide nanocrystals have attracted much attention because each component in this type of ternary composites is biodegradable, and the final properties are more easily tailored comparing to those of binary composites. In this work, chitin nanocrystals (ChNCs) were used as nanofiller for the biodegradable poly(ε-caprolactone) (PCL)/polylactide (PLA) immiscible blend to prepare ternary composites for a crystallization study. The results revealed that the crystallization behavior of PCL/PLA blend matrices strongly depended on the surface properties of ChNCs. Non-modified ChNCs and modified ChNCs played completely different roles during crystallization of the ternary systems: the former was inert filler, while the latter acted as anti-nucleator to the PCL phase. This alteration was resulted from the improved ChNC-PCL affinity after modification of ChNCs, which was due to the 'interfacial dilution effect' and the preferential dispersion of ChNCs. This work presents a unique perspective on the nucleation role of ChNCs in the crystallization of immiscible PCL/PLA blends, and opens up a new application scenario for ChNCs as anti-nucleator. • ChNCs had preferential dispersion in continuous PCL phase of PCL/PLA blend. • ChNCs changed from inert particles to anti-nucleator for PCL after modification. • Both pristine and modified ChNCs restrained cold crystallization of PLA phase. [ABSTRACT FROM AUTHOR]

Background: Cellular communication is an essential feature of multicellular organisms. Binding of ligands to their homologous receptors, which activate specific cell signaling pathways, is a basic type of cellular communication and intimately linked to many degeneration processes leading to diseases. Main body: This study reviewed the history of ligand-receptor and presents the databases which store ligand-receptor pairs. The recently applications and research tools of ligand-receptor interactions for cell communication at single cell level by using single cell RNA sequencing have been sorted out. Conclusion: The summary of the advantages and disadvantages of analysis tools will greatly help researchers analyze cell communication at the single cell level. Learning cell communication based on ligand-receptor interactions by single cell RNA sequencing gives way to developing new target drugs and personalizing treatment. [ABSTRACT FROM AUTHOR]

Elevated atmospheric carbon dioxide (CO 2) concentration generally stimulates nitrous oxide (N 2 O) emissions from upland soils, leading to a promoted feedback on climate change. However, the underlying mechanisms on how elevated CO 2 (eCO 2) stimulates N 2 O emissions from nitrogen (N)-fertilized upland soils remain poorly known. Here, we investigated the effects of eCO 2 on soil N 2 O production pathways and associated gross N transformation rates, as well as on nitrifying and denitrifying microbes. Based on a 13 years of free-air CO 2 enrichment (FACE) platform, we found that N 2 O emissions were significantly increased by 46.7% under eCO 2 in a typical summer-maize field. The 15N tracing experiment showed that autotrophic nitrification rate was significantly increased by 11.6% under eCO 2 , coincided with the significantly higher abundance and shift composition of ammonia-oxidizing bacteria (AOB) under eCO 2. Also, eCO 2 enhanced gross ammonium (NH 4 +) immobilization rate but reduced gross nitrate (NO 3 −) immobilization rate. Autotrophic nitrification accounted for approximately 78% of N 2 O emissions, followed by heterotrophic nitrification (about 19%) and denitrification (about 3%). It was found that eCO 2 increased carbon (C) deposition in soil, which could affect the availability of soil labile organic C and N and alter the composition and activity of nitrifiers. These changes promoted the N 2 O production derived from autotrophic nitrification, resulting in higher N 2 O emissions under eCO 2. We could deduce that nitrifier denitrification contributed to the increased N 2 O emissions greatly under eCO 2 , derived by strongly stimulated ammonia oxidation and microbial respiration (i.e. higher soil CO 2 emissions) caused suboxic conditions (i.e. lower soil oxygen (O 2) concentration), along with higher abundance ratios of (nirK + nirS)/ nosZ. Our results suggest that controlling autotrophic nitrification appropriately is crucial for mitigating N 2 O emissions from upland soils under rising atmospheric CO 2 concentration. [Display omitted] • Elevated CO 2 significantly increased soil N 2 O emissions from the maize field. • Autotrophic nitrification was the main N 2 O production pathway. • Elevated CO 2 significantly enhanced autotrophic nitrification and N 2 O emission product ratio. • Elevated CO 2 significantly increased soil nitrifiers and denitrifiers abundances. [ABSTRACT FROM AUTHOR]

Abstract Two labeled and non-label electrochemical peptide-based biosensors for highly sensitive and selective determination of hemopexin domain of matrix metalloproteinase-14 (PEX-14) were reported for the first time. Herein, the thiolated PEX-14 binding peptide inhibitor (ISC) or the ISC-tagged with ferrocene carboxylic acid (CIS-Fc) was self-assembled on the surface of gold electrode tested for binding with PEX-14 by non-label electrochemical impedance spectroscopy or labeled electrochemical (L-EC) transducers. The two biosensors were compared for the analytical performance of the detection of PEX-14 with detection limit of 0.3 pg mL−1 (for L-EC biosensor) and 0.03 ng mL−1 (for EIS biosensor). This work demonstrates that probing the PEX of MMPs represents a novel approach to assess MMPs-mediated cancer dissemination and provide a platform for screening the inhibitors of Matrix metalloproteinases. Graphical abstract fx1 Highlights • Peptides selected by PEX domain, which is crucial for many specific MMP functions, can also inhibit MMPs and be expected to be further promoted and applied. • Electrochemical impedance spectroscopy (EIS) is a very powerful tool for the analysis of interfacial properties related to biorecognition events occurring at the modified surfaces. • First designed two EC biosensors on basis of peptide inhibitor for the determination of MMP were fabricated. • Two orthogonal transducers EIS and electrochemical readouts for widening the detection dynamic range and to introduce the internal validation. • The strategy could be easily applied as an ideal sensing platform for the detection of MMPs-mediated cancer dissemination, laying the foundation for cancer diagnosis and prognostic evaluation. [ABSTRACT FROM AUTHOR]

Abstract A new electrogenerated chemiluminescence (ECL) biosensor is fabricated for the determination of mental ion incorporating DNA three-way junction structure (DNA-TWJ). As a model system, Hg2+ was chosen as an analyte. The ECL biosensor was fabricated by covalently coupling Hg2+ special DNA-TWJ tagged with ruthenium (II) complex (Ru) (named TW/Ru-J1) to the surface of glassy carbon electrode that had been covalently modified with 4-aminobenzoic acid via electrochemical oxidations. Upon binding of Hg2+ to the TW/Ru-J1, the confirmation of TW/Ru-J1 changed and induced Ru away from surface of electrode and thus led to a low ECL signal. The signal linearly decreases with the concentration of Hg2+ in the range from 0.1 pM to 10 pM with a detection limit of 0.04 pM This study could be easily extended to various analytical platforms for the detection of many kinds of analytes or their interactions such as DNA/RNA, DNAzyme/target, aptamer/target, and antibody/antigen. Highlights • DNA three-way junction (DNA-TWJ) is a unique branched structure and consists of three double helical arms connected at the junction point. • First designed ECL biosensor on basis of DNA-TWJ for the determination of mercury ion is fabricated. • The obtained detection limit of 0.04 pM is much lower than that from other latest reported methods based on T–Hg2+–T interactions. • The strategy can open a new door toward the development of the detection method for metal ions or biomarkers on biochips. [ABSTRACT FROM AUTHOR]

Using polysaccharide nanocrystals such as chitin nanocrystals (ChNCs) as nanofiller for biodegradable aliphatic polymers is an attractive way of developing all-degradable nanocomposites. Crystallization study is vital for well regulating final performance of these type polymeric nanocomposites. In this work, ChNCs were incorporated with the poly(l -lactide)/poly(d -lactide) blends and as-obtained nanocomposites were used as target samples for the study. The results showed that ChNCs acted as nucleating agent, promoting the formation of stereocomplex (SC) crystallites and accelerating overall crystallization kinetics as a result. Therefore, the nanocomposites possessed higher SC crystallization temperatures and lower apparent activation energy as compared to the blend. However, the formation of homocrystallites (HC) was dominated by nucleation effect of SC crystallites and accordingly, the fraction of SC crystallites reduced more or less in the presence of ChNCs, despite the nanocomposites possessed higher rate of HC crystallization. This study also provided valuable information on accessing more applications of ChNCs to be used as SC nucleator for polylactide. • ChNCs acted as SC nucleator and promoted the stereocomplexation of PLLA. • Nanocomposites showed accelerated kinetics and lower SC activation energy. • The fraction of SC crystallites deceased more or less in the presence of ChNCs. [ABSTRACT FROM AUTHOR]

A label free lectin biosensor developed in our laboratory that can quantitatively measure the binding between the lectin immobilized at the carbohydrate sensor surface and the lipopolysacchaiide (LPS) on Gram-negative bacteria was demonstrated for an antibiotic susceptibility assay. The biosensor utilizes a polythiophene interface containing fused quinone moieties glycosylated to form a carbohydrate platform for the immobilization of Concanavalin A (Con A) and is capable of LPS binding measurements via orthogonal quartz crystal microbalance and electrochemical readouts (EQCM). Such orthogonal transduction provides cross-validation, better sensor sensitivity and a large dynamic range of the measurements. We have applied this label free lectin biosensor for a new antibiotic susceptibility assay by characterizing the antimicrobial activities of various antibiotics (i.e., ciprofloxacin, ceftriaxone, and tetracycline) against Lhcnclua coh W1485 as a model system. The label free biosensor allows both end point and real time measurements of antibiotic effects on the bacterial cell surface LPS, which is shown to correlate to their antibiotic effects. At the end point after 18 h incubation of bacterial cells with these three antibiotics respectively, the bacterial LPS binding signal was reduced to 23%, 27%, and 38%, respectively, for the three antibiotics, indicating that ciprofloxacin is the most effective against this E. coli strain. Real time measurements at the 1 h time point showed a similar trend with a reduction of binding to 91%, 93%, and 95%, respectively From the binding kinetics of these measurements, the relaxation time (τ) was obtained, where higher τ value means slow binding interactions between the lectin and the bacterial LPS. The obtained order of τ, (i.e., τciprofloxacin > τ ceftriaxone > τtetracycline) again indicated that ciprofloxacin has more bactericidal activity titan the other two antibiotics with the same concentrations Thus, we are able to establish that the reduction in the binding of LPS with the lectin Con A sensor upon exposure to various antibiotics has a direct relation with the antibiotic dosages making this label free biosensor assay promising for therapeutic management of these drugs as well as for applications in antibiotic research and development. [ABSTRACT FROM AUTHOR]

Abstract: We report herein an aptamer-based electrochemical biosensor for the quantitative determination of mucin 1 (MUC1), a glycoprotein expressed on most epithelial cell surfaces, based on the analyte-binding induced, global-scale conformational change of electrode-bound anti-MUC1 DNA aptamers. The modified electrode was readily prepared by directly immobilizing thiolated, single-stranded anti-MUC1 DNA aptamers on gold; they were also tethered at the distal end with methylene blue (MB) for electrochemical measurements. In the absence of MUC1, these DNA single strands fold into a thermodynamically stable “hairpin” conformation, which facilities direct electron transfer between MB and the gold electrode. Upon MUC1 binding, the aptamer no longer retains its inherent hairpin conformation, which relocates the redox center (MB) further away from the electrode surface. The surface density of the DNA aptamer probes on gold measured by MB voltammetric response is consistent with that of electrostatically bound [Ru(NH3)6]3+, indicating that every MB molecule is electroactive at low scan rates; yet, the electroactivity of MB decreases remarkably upon binding MUC1. The detection limit (50nM) and dynamic response range (up to 1.5μM) are superior to the commercially available enzyme-linked immunosorbent assay (ELISA) kits and our previously developed quantum dot-based fluorescence protocol. The sensing principle pertaining to the specific folding conformation described in this paper has the potential to serve as a general approach of using hairpin DNA aptamers to construct biosensors for other molecular analytes. [Copyright &y& Elsevier]

The elevated atmospheric CO2 concentration (eCO2) is expected to increase the labile C input to the soil, which may stimulate microbial activity and soil N2O emissions derived from nitrification and denitrification. However, few studies studied the effect of eCO2 on N2O emissions from maize field under the free-air CO2 enrichment (FACE) conditions in the warm temperate zone. Here, we report a study conducted during the 12th summer maize season under long-term eCO2, aiming to investigate the effect of eCO2 on N2O emissions. Moreover, we tested zero and conventional N fertilization treatments, with maize being grown under either eCO2 or ambient CO2 (aCO2). We hypothesized that N2O emissions would be increased under eCO2 due to changes in soil labile C and mineral N derived from C-deposition, and that the increase would be larger when eCO2 was combined with conventional N fertilization. We also measured the activities of some soil extracellular enzymes, which could reflect soil C status. The results showed that, under eCO2, seasonal N2O and CO2 emissions increased by 12.4–15.6% (p < 0.1) and 13.8–18.5% (p < 0.05), respectively. N fertilization significantly increased the seasonal emissions of N2O and CO2 by 33.1–36.9% and 17.1–21.8%, respectively. Furthermore, the combination of eCO2 and N fertilization increased the intensity of soil N2O and CO2 emissions. The marginal significant increase in N2O emissions under eCO2 was mostly due to the lower soil water regime after fertilization in the study year. Dissolved organic C (DOC) and microbial biomass C (MBC) concentration showed a significant increase at most major stages, particularly at the tasseling stage during the summer maize growth period under eCO2. In contrast, soil mineral N showed a significant decrease under eCO2 particularly in the rhizospheric soils. The activities of C-related soil extracellular enzymes were significantly higher under eCO2, particularly at the tasseling stage, which coincided with concurrent increased DOC and MBC under eCO2. We conclude that eCO2 increases N2O emissions, and causes a higher increase when combined with N fertilization, but the increase extent of N2O emissions was influenced by environmental factors, especially by soil water, to a great extent. We highlighted the urgent need to monitor long-term N2O emissions and N2O production pathways in various hydrothermal regimes under eCO2. [ABSTRACT FROM AUTHOR]

Abstract: A novel electrogenerated chemiluminescence (ECL) biosensor for highly sensitive and selective detection of mercury ion was developed on the basis of mercury-specific oligonucleotide (MSO) served as a molecular recognition element and the ruthenium(II) complex (Ru1) as an ECL emitting species. The biosensor was fabricated on a glassy carbon electrode coated with a thin layer of single wall carbon nanotubes, where the ECL probe, NH2-(CH2)6-oligo(ethylene oxide)6-MSO↔Dend-Ru1, was covalently attached. The Dend-Ru1 pendant was prepared by covalent coupling Ru1 with the 4th generation polyamidoamine dendrimer (Dend), in which each dendrimer contained 35 Ru1 units so that a large amplification of ECL signal was obtained. Upon binding of Hg2+ to thymine (T) bases of the MSO, the T–Hg–T structure was formed, and the MSO changed from its linear shape to a “hairpin” configuration. Consequently, the Dend-Ru1 approached the electrode surface resulting in the increase of anodic ECL signal in the presence of the ECL coreactant tri-n-propylamine. The reported biosensor showed a high reproducibility and possessed long-term storage stability (92.3% initial ECL recovery over 30 day''s storage). An extremely low detection limit of 2.4pM and a large dynamic range of 7.0pM to 50nM Hg2+ were obtained. An apparent binding constant of 1.6×109 M−1 between Hg2+ and the MSO was estimated using an ECL based extended Langmuir isotherm approach involving multilayer adsorption. Determination of Hg2+ contents in real water samples was conducted and the data were consistent with the results from cold vapor atomic fluorescence spectroscopy. [Copyright &y& Elsevier]

Abstract: A highly reproducible and sensitive signal-on electrogenerated chemiluminescence (ECL) biosensor based on the DNAzyme for the determination of lead ion was developed. The ECL biosensor was fabricated by covalently coupling 5′-amino-DNAzyme-tagged with ruthenium bis (2,2′-bipyridine) (2,2′-bipyridine-4,4′-dicarboxylic acid)-ethylenediamine (Ru1-17E′) onto the surface of graphite electrode modified with 4-aminobenzoic acid, and then a DNA substrate with a ribonucleotide adenosine hybridized with Ru1-17E′ on the electrode. Upon binding of Pb2+ to the Ru1-17E′ to form a complex which catalyzed the cleavage of the DNA substrate, the double-stranded DNA was dissociated and thus led to a high ECL signal. The signal linearly increases with the concentration of Pb2+ in the range from 5.0 to 80pM with a detection limit of 1.4pM and a relative standard derivation of 2.3%. This work demonstrates that using DNAzyme tagged with ruthenium complex as an ECL probe and covalently coupling method for the fabrication of the ECL biosensor with high sensitivity, good stability and significant regeneration ability is promising approach. [Copyright &y& Elsevier]

We reported here two novel electrochemical impedance spectroscopy biosensors were developed for the first time for highly sensitive quantification of matrix metalloproteinase-14 (MMP-14) based on binding interaction between hemopexin-like domain (PEX) of MMP-14 (PEX-14) and its inhibitory peptides. Specific inhibitory peptides (IVSC or ISC) inhibiting homodimerization or heterodimerization of MMP-14 was first self assembled on the surface of gold electrode and blocked with 6-mercapto-1-hexanol on a gold electrode surface used as IVSC or ISC modified biosensor, respectively. IVSC modified biosensor can be used for detection of MMP-14 by using the direct IVSC-MMP-14 interaction inhibiting MMP-14 homodimerization as well as ISC modified biosensor for indirect detection of MMP-14 via PEX-14 mediated peptide-MMP-14 binding. The electron transfer resistance (R et) of biosensor was monitored to measure MMP-14 using Fe(CN) 6 3−/4- as probe. The increase of the R et of the biosensors are linear with the concentration of MMP-14 in the range from 1 μg L−1 to 10 μg L−1 with detection limit of 0.19 μg L−1 for IVSC modified biosensor and 0.1 ng L−1 to 50 ng L−1 with detection limit of 7 ng L−1 for ISC modified biosensor. This work demonstrates that probing the interaction between peptide inhibitor and PEX of MMPs represents a novel approach to assess MMPs-mediated cancer dissemination. Image 1 • Specific inhibitory peptides (IVSC or ISC) selected by PEX domain, which is crucial for many specific MMP functions, can also inhibit MMPs and be expected to be further promoted and applied. • IVSC or ISC inhibiting homodimerization or heterodimerization of MMP-14 was first used to fabricated electrochemical impedance spectroscopy (EIS) biosensor. • Two EIS biosensors widened the detection dynamic range and enhanced the sensitivity and limit of detection. [ABSTRACT FROM AUTHOR]

Background: It is well known that litter releases dissolved organic carbon (DOC), which would impact the role of litter in soil nitrogen (N) transformation. Thus, this study aimed to explore the effect of litters decomposed at different levels on soil N dynamics in the presence of labile carbon. Methods: An incubation experiment was carried out with fresh litter (SF), partially decomposed litter (SP) or the combined addition of glucose and alanine in soils for 210 days. The influence of litter addition on soil was investigated by changes of soil soluble organic N, NH4+‐N, NO3−‐N and microbial biomass N (MBN). Results: There was higher soil NH4+‐N and NO3−‐N in SF, nonetheless lower in SP than control. Litter addition decreased soil dissolved organic N (DON), but increased DOC compared to control. These results suggested that the effects of litter on soil N might change with the varying status of decomposed litter. Alanine addition increased each soil N form, which was more of DON and less of MBN in SP than SF. After adding amino acids, the priming amount of DON was computed positive at 0.5 day with the highest soil MBN, simultaneously. Moreover, the net N transformation rate preceded the gross rate. Glucose addition also improved soil NH4+‐N and DON more in SP than SF, while lessened MBN in SF than SP. These results indicated that the differential effect of labile C sources, alanine and glucose, on soil N might be related to the chemistry of the differently decomposed litter. As a labile C source, glucose had a lesser effect on soil N than alanine. Conclusions: Our findings highlighted the coexistence of litters at varied decomposition status and C sources released from litters, which are contributed to the N dynamics in soil and are critical for the ecological functioning of the degraded litter. [ABSTRACT FROM AUTHOR]

Inspired by the signal transduction function of organophosphates in biological systems, bioactive organophosphates were utilized for the first time as chiral nodes to dictate the stereoselective assembly of hydrogen‐bonded anionic cages. Phosphonomycin (antibiotics), tenofovir (antivirals), adenosine monophosphate (natural product, AMP) and clindamycin phosphate (antibiotics) were assembled with an achiral bis‐monourea ligand, thereby leading to the stereoselective formation of quadruple or triple helicates. The extent of the stereoselectivity could be enhanced by either lowering the temperature or adding stronger‐binding cations as templates. With the chiral anionic cages as the host, some enantioselectivity was achieved when binding chiral quaternary ammonium cations. [ABSTRACT FROM AUTHOR]

Inspired by the signal transduction function of organophosphates in biological systems, bioactive organophosphates were utilized for the first time as chiral nodes to dictate the stereoselective assembly of hydrogen‐bonded anionic cages. Phosphonomycin (antibiotics), tenofovir (antivirals), adenosine monophosphate (natural product, AMP) and clindamycin phosphate (antibiotics) were assembled with an achiral bis‐monourea ligand, thereby leading to the stereoselective formation of quadruple or triple helicates. The extent of the stereoselectivity could be enhanced by either lowering the temperature or adding stronger‐binding cations as templates. With the chiral anionic cages as the host, some enantioselectivity was achieved when binding chiral quaternary ammonium cations. [ABSTRACT FROM AUTHOR]

Elevated atmospheric CO2 concentrations (eCO2) has become the main feature and cause of global change that could affect crop growth in many aspects, including physiological processes and morphological development in plants and nutrient cycling and nutrient uptake from the soil. Studying the responses of crop growth to different nitrogen (N) supply forms under elevated atmospheric CO2 concentrations can guide nutrient management strategies for agricultural production under future climate change scenarios. Few studies addressed the effect of eCO2 on N uptake and morphological development for plants. This study was conducted in the CO2-controlled light incubators based on the sand-pot incubation using wheat and maize as experimental plants. Six treatments were set with two different environmental CO2 concentrations (aCO2, 390 µmol mol−1; eCO2, 690 µmol mol−1) and three different N supply forms, including ammonium−N, nitrate−N and ammonium-nitrate with 1:1 ratio. The following results were obtained: (i) Wheat and maize seedlings, as nitrate-preferring crops, grew better under mixed N forms than under single N forms. For the single N supply treatment, seedlings with nitrate−N supply showed better growth than with ammonium. (ii) For wheat plants, seedlings with a single ammonium−N supply showed slender height and fewer tillers; seedlings with a single nitrate−N supply were characterized by slightly shorter plant height, more tillers, and higher aboveground biomass. (iii) Compared to the aCO2 group, wheat seedlings with the ammonium−N supply showed an increased maximum root length and a decreased carbon concentration in root exudates; wheat seedlings with a single nitrate−N supply under eCO2 showed a significant increase in biomass and a decreased carbon concentration in root exudates; wheat seedlings with a mixed N supply under eCO2 explored a significant increase in carbon concentration in root exudate and a relatively lower N concentration. (iv) For maize plants, seedlings with either single ammonium−N or nitrate−N supply did not show significant differences in most growing indices. Maize seedlings with a mixed N supply exhibited an increase in aboveground biomass and N concentration in root exudates compared to those with a single N supply. (v) Compared with the aCO2 group, maize seedlings with mixed N supply under eCO2 conditions exhibited significant increases in plant height, aboveground biomass, and N concentration in root exudates. Single ammonium−N supply was toxic to wheat and maize plants under eCO2 conditions. We recommend raising the ratio of ammonium-to-nitrate under mixed N supply to improve the coordination of carbon and N metabolism for efficient crop growth under climatic change conditions of elevated atmospheric CO2 concentration. [ABSTRACT FROM AUTHOR]

Molecular imprinting materials can successfully improve the efficacy and safety of drugs, thus showing good potential in the field of drug delivery. However, some difficulties in imprinted materials, such as the deep embedding of imprinting sites and poor accessibility, limit their application. Herein, we have developed porous designed molecularly imprinted polymers (MIPs) based on cleavage hyperbranched polymers for thiamine hydrochloride controlled release. By introducing hyperbranched polymers with terminal double bonds and sensitive disulfide bonds, the resulting porous MIPs (PMIPs) can expose more effective recognition sites and improve the drug-controlled release behavior, where significantly improved the drug loading (101.25 mg g−1) compared with the porous non-imprinted polymers (PNIPs, 16.57 mg g−1). Moreover, under the optimized conditions of pH 1.7 and 25 °C, the whole drug release time was increased from 16 h (PNIPs) to 32 h (PMIPs). As a result, this porous structure of MIPs designed approach provides an insight to fabricating improved imprinted constituents with higher adsorption capacity and faster recognition kinetics, which not only inspires more brilliant work in the future but also paves the way for the application of MIPs in the field of drug delivery. [ABSTRACT FROM AUTHOR]

Bone metastasis is common in breast cancer and more effective therapies are required, however, its molecular mechanism is poorly understood. Additionally, the role of the m6A reader YTHDF1 in bone metastasis of breast cancer has not been reported. Here, we reveal that the increased expression of YTHDF1 is clinically correlated with breast cancer bone metastases. YTHDF1 promotes migration, invasion, and osteoblast adhesion and induces osteoclast differentiation of cancer cells in vitro and vivo. Mechanically, RNA-seq, MeRIP-seq and RIP-seq analysis, and molecular biology experiments demonstrate that YTHDF1 translationally enhances EZH2 and CDH11 expression by reading m6A-enriched sites of their transcripts. Moreover, adeno-associated virus (AAV) was used to deliver shYTHDF1 (shYTHDF1-AAV) in intratibial injection models, eliciting a significant suppressive effect on breast cancer bone metastatic formation and osteolytic destruction. Overall, we uncovered that YTHDF1 promotes osteolytic bone metastases of breast cancer by inducing EZH2 and CDH11 translation. • YTHDF1 overexpression clinically correlates with breast cancer bone metastases. • YTHDF1 promotes migration, invasion, osteoblast adhesion and induces osteoclast differentiation of breast cancer cells. • YTHDF1 promotes translation of the key bone metastatic genes EZH2 and CDH11. • ShYTHDF1-AAV potently inhibits breast cancer bone metastatic formation and osteolytic destruction. [ABSTRACT FROM AUTHOR]

In this paper, an analogue of hirsutine (compound 1) has been synthesized and evaluated as an anti-hypertension agent, which exhibits extraordinary effects on the contractile response of thoracic aorta rings from male SD rats in vitro (IC50 = 1.129×10-9±0.5025) and the abilities of reducing the systolic blood pressure (SBP) and heart rate (HR) of SHR in vivo. The mechanism investigation reveals that the vasodilatation induced by compound 1 is mediated by both endothelium-dependent and -independent manners. The relaxation in endothelium-intact aortic rings induced by compound 1 can be inhibited by L-NAME (1×10-6 mol•L-1) and ODQ (1×10-6 mol•L-1). Moreover, compound 1 can also block Ca2+ influx through L-type Ca2+ channels and inhibit intracellular Ca2+ release while no effect on K+ channel has been observed. All these data demonstrated that the NO/cyclic GMP pathway can be involved in endothelium-dependent manner induced by compound 1. Meanwhile the mechanism on the vasodilatation of compound 1 probably also related to blockade of Ca2+ influx through L-type Ca2+ channels and inhibition of intracellular Ca2+ release may have no relationship with K+ channels. [ABSTRACT FROM AUTHOR]

In this work, we prepared poly- L -lysine (PLL) functionalized magnetic graphene through a simple covalent bonding process. The composite was further conjugated with aspartic acid (Asp) and chelated copper ions to obtain a metal affinity PLL-functionalized magnetic graphene composite (MGPLA-Cu). Various characterizations via FT-IR, XRD, TGA, VSM and SEM/TEM confirm its physicochemical properties. Owing to the strong metal affinity forces between metal affinity groups and the residual histidine in proteins, the MGPLA-Cu composite exhibits highly selective adsorption performance toward histidine-rich proteins, i.e., hemoglobin (Hb) in this case. A high adsorption efficiency of ca. 100% was achieved for 200 mg L−1 Hb in a phosphate buffer at pH 8. The equilibrium adsorption isotherm of Hb on the MGPLA-Cu composite well fitted to the Langmuir theoretical model (R2 = 0.9969), along with the maximum adsorption capacity (qmax) at 334 mg g−1. The adsorption kinetics was favorably described by the pseudo-second-order kinetic model. The retained Hb could be effectively recovered with a 0.2 mol L−1 carbonate buffer containing 0.05 mol L−1 imidazole at pH 10, giving rise to a recovery of ca. 97%. The MGPLA-Cu composite showed favorable reusability, and a high adsorption efficiency (>80%) was maintained after five adsorption–desorption operation cycles. The practical application demonstrates that the MGPLA-Cu composite can isolate Hb from human whole blood with high selectivity and high purity. [ABSTRACT FROM AUTHOR]

There were more robust IgA, IgG, and IgM responses in severe patients, more rapid but less robust IgA and IgG responses in asymptomatic and mild patients. To investigate whether the serological assay of different antibody isotypes could improve the early diagnostic power of COVID-19 patients, the seroconversion rates of single or combined antibody isotypes and the detection of viral RNA in the first month after disease onset were analyzed irrespective of disease severity. This study provides a comprehensive dynamic analysis of different antibody isotypes against SARS-CoV-2 and their relation to disease severity or early COVID-19 diagnosis in a large patient cohort over a 6-month follow-up period, which will benefit the early diagnosis and assessment of disease severity for COVID-19. To understand the correlation between antibody responses and disease severity, the levels of viral-specific IgA, IgG, and IgM were analyzed in four groups, and their kinetics are shown in Figures 1A-C and 2A-C. All three antibody isotypes (IgA, IgG, and IgM) peaked 1 month after disease onset (Figure 1A-C). [Extracted from the article]

Two novel electrochemiluminescence (ECL) deoxyribosensors are designed for assay of early lung cancer biomarker (NAP2) using the DNA three-way junction (DNA-TWJ) inserted NAP2 binding aptamer between two double-helical stems and labeled with ruthenium (II) complex (Ru) (NBAT-Ru) taken as molecular recognition element. The signal-off ECL deoxyribosensor was fabricated by covalently coupling the 5′–NH 2 –(CH 2) 6 -NBAT-Ru to glassy carbon electrode surface modified with 4-aminobenzoic acid (4-ABA). After combining NAP2 and NBAT-Ru, the changed conformation of NBAT-Ru altered the distance between Ru complex and electrode, resulting in a low ECL signal. The signal-on deoxyribosensor was fabricated by self-assembling the 5′–SH–(CH 2) 6 -NBAT-Ru onto the Au electrode. The introduction of NAP2 triggered the conformational change in the aptamer domain, which induces the interhelical stacking of the two double-helical stems of NBAT-Ru. This stacking constitutes "electrical contact," which promotes transmission of electron-holes through the stems of NBAT-Ru, and produces high ECL intensity. Both deoxyribosensors show high sensitivity and selectivity. The biosensors have been successfully applied to clinical plasma detection. The approaches we describe represent unique principles based on DNA-TWJ inserted target special binding domain as molecular recognition element and different immobilization types for the fabrication of biosensors, which are greatly promising for the detection of protein, metal ions, bacteria, and cells. Image 1 • Two novel ECL deoxyribose sensors are designed combining advantages of ECL biosensors and DNA-TWJs. • ECL deoxyribose sensors avoid the disadvantages of traditional aptasensors. • The deoxyribose sensors have been successfully applied to detect lung cancer biomarker (NAP2) for the first time. [ABSTRACT FROM AUTHOR]

Highlights • Nitrate Accounted for 80–95% of total N leaching. • N leaching increased with increasing N application rate. • Various measures could decrease N leaching loss. Abstract Agriculture has contributed greatly to nitrogen (N) pollution globally. It is essential to study the causes and characteristics of N leaching to develop better N management strategies. A field experiment with cucumber–Chinese cabbage rotation was conducted in a typical open field for vegetable planting in northern China. The characteristics of N leaching were studied using the lysimeter method. The total N leaching (TNL) value under the conventional N application rate (780 kg ha−1 season−1) was 585.3 kg ha−1 for the entire vegetable year and it had a significantly positive correlation with the N application rate. Reduction of the N rate by 20% and 50% could decrease the TNL by 18.3% and 43.0% during the entire cucumber and cabbage season (including the fallow period), respectively. A 20% reduction in the N rate had no obvious impact on vegetable yields. The TNL was decreased by 2.6% throughout the year under a combined application of manure and chemical fertilizers. An amendment with a urease-inhibitor plus a nitrification-inhibitor, biochar, and straw could decrease TNL by 23.5%, 15.3%, and 7.1%, respectively, compared to that without amendments. A combined reduction of N and the irrigation rate by 20% showed a decrease of the TNL by 38.4%. The results showed that N leaching substantially contributed to the loss of fertilizer N in a typical vegetable field in northern China, where both the temperature and the rainfall were synchronized. Appropriate management practices can effectively reduce the TNL at different degrees without the negative impact on vegetable yields. These practices include the addition of synergists (urease inhibitors and nitrification inhibitors), the amendment with biochar or straw, and the reduction in both N rate and irrigation volume by 20%. Different measures can be adopted in the actual vegetable production according to the specific conditions. [ABSTRACT FROM AUTHOR]

Phosphorylation of serine 81 (pS81) in the N-terminal transactivation domain of the androgen receptor (AR) has been linked to its transcriptional activation in prostate cancer (PCa) cell lines, but in vivo studies have been limited. Moreover, the role of pS81 in the reactivation of AR when tumors relapse after androgen deprivation therapy (castration-resistant prostate cancer, CRPC) has not been determined. In this study we validate a pS81 antibody for immunohistochemistry (IHC) and show it yields strong nuclear staining in primary PCa clinical samples and in the VCaP PCa xenograft model. Moreover, this staining was decreased at 7 days post-castration in VCaP xenografts, coinciding with markedly decreased AR transcriptional activity. Staining with the pS81 antibody then was restored when the VCaP xenografts relapsed, which was associated with restoration of AR transcriptional activity. Significantly, analysis of CRPC clinical samples, including tumors that had progressed during treatment with abiraterone, showed strong nuclear staining with the pS81 antibody. Together these findings indicate that AR reactivation in CRPC is associated with S81 phosphorylation, and suggest that IHC for pS81 may be useful as a biomarker of AR activity in CRPC. [ABSTRACT FROM AUTHOR]

The previously generated recombinant human (rh) interferon (IFN)-λ1 protein has a short half-life, and this feature makes it challenging to conduct studies on potential clinical applications for rhIFN-λ1. In an attempt to overcome this difficulty, we constructed a 'long-life' version of rhIFN-λ1. This modified rhIFN-λ1, named rhIFN-λ1-CTPON, has a human chorionic gonadotropin β subunit carboxyl-terminal peptide (CTP) and an N-glycosylation sequence linked to its C-terminus. We confirmed the sequence of rhIFN-λ1-CTPON by mass spectrometry and then measured its biological activities. The results show that rhIFN-λ1-CTPON had antiviral activity and anti-proliferation activity in vitro that were similar to those of rhIFN-λ1 and that it similarly promoted natural killer cell cytotoxicity. Notably, the in vivo half-life of rhIFN-λ1-CTPON was determined to be 3-fold higher than that of rhIFN-λ1. We also assessed the anti-hepatitis B virus activity of rhIFN-λ1-CTPON; it was able to inhibit the production of the antigens HBs-Ag and HBe-Ag and induce antiviral gene expression. In conclusion, rhIFN-λ1-CTPON has a longer half-life than rhIFN-λ1 and has similar biological activities, so rhIFN-λ1-CTPON is an appropriate substitute for rhIFN-λ1 in the further study of potential clinical applications for rhIFN- λ1. [ABSTRACT FROM AUTHOR]

[Display omitted] • ECL biosensor was designed on basis of heterodimerization interaction between CD44 and hemopexin-like domain (PEX) of MMP-14 (PEX-14). • The Ru complex attached to the Co, Mo 2 C-CNF@PDA-modified surface enhance the ECL signal gained, which facilitates the sensitivity of detection. • No need to tag the protein thus maintains the protein activity to some extent. CD44, which is expressed frequently and predominantly in invasive tumor cells, is substrate of a membrane-type matrix metalloproteinase (MT1-MMP, also named MMP-14) and its processing accompanies promotion of cell migration. The hemopexin-like domain of MMP-14 (PEX-14) is the region responsible for association with CD44. An electrogenerated chemiluminescence (ECL) biosensor was developed firstly for highly sensitive quantification of CD44 based on heterodimerization interaction between CD44 and PEX-14. In the work, PEX-14 was chosen to specially recognize target CD44. ECL emitter, ruthenium complex (Ru), was covalently coupled onto the surface of Co, Mo 2 C-carbon nanofiber@polydopamine (Co, Mo 2 C-CNF@PDA) modified glassy carbon electrode. PEX-14 was further attached to the modified surface, the ECL fabricated successfully. In theory, the ECL signal decreases after binding to CD44. Under the optimal experimental conditions, the designed biosensor exhibited excellent sensitivity with a wide linear range of 0.002–250 ng mL−1 and a detection limit of 0.001 ng mL−1. The biosensor is demonstrated by detecting of living cells expressing CD44 (MDA-MB-231 cancer cells as model). The development of the label-free ECL biosensor integrated with functionalized nanofiber will provide a prospect for studying invasion and metastasis of cancer cells based on the interaction between CD44 and PEX of MMPs. [ABSTRACT FROM AUTHOR]

[Display omitted] • A sandwich electrogenerated chemiluminescence biosensor was firstly developed for determination of matrix metalloproteinase; • Non-specific adsorption due to cleavage is avoided; • Sensitivity is enhanced since sandwich mode provide zero signal background; • The detection of MMPs is more specialized since one MMP identified by the two peptides. A novel electrogenerated chemiluminescence (ECL) biosensor based on sandwich structure between target and inhibitory peptides was firstly developed for determination of matrix metalloproteinase and its expressing cancer cells. Here, target MMP-14 was used as model protein. Inhibitory peptide (AP1) was used as capture probe. Ruthenium complex (Ru) tagged inhibitory peptide (AP2) was used as signal probe (Ru-AP2) in this work. The biosensors were fabricated by covalently coupling Cys group of AP1 onto the surface of functional fullerene-chitosan (C60-Chit) nanocomposite modified glassy carbon electrode. Upon binding of MMP-14, Ru-AP2 further specially bound to MMP-14 and a sandwich format formed, and increasing ECL signal was obtained. Under the optimal experimental conditions, the designed biosensor exhibited excellent sensitivity with a wide linear range of 0.05–7 pg mL−1 and a detection limit of 0.008 pg mL−1. The biosensor is demonstrated by detecting of living cells expressing MMPs (MDA-MB-231 cancer cells as model) and distinguish the expression MMPs in different cells. Our work firstly fabricated a sandwich ECL biosensor for determination of MMPs and MMPs relative cancer cells based on the interaction between peptide inhibitors and PEX of MMPs, which will provide a platform to study the mechanism of MMP and inhibitors. [ABSTRACT FROM AUTHOR]

Abstract: A simple and highly sensitive electrochemical impedance spectroscopy (EIS) biosensor based on a thrombin-binding aptamer as molecular recognition element was developed for the determination of thrombin. The signal enhancement was achieved by using gold nanoparticles (GNPs), which was electrodeposited onto a glassy carbon electrode (GCE), as a platform for the immobilization of the thiolated aptamer. In the measurement of thrombin, the change in interfacial electron transfer resistance of the biosensor using a redox couple of [Fe(CN)6]3−/4− as the probe was monitored. The increase of the electron transfer resistance of the biosensor is linear with the concentration of thrombin in the range from 0.12nM to 30nM. The association and dissociation rate constants of the immobilized aptamer–thrombin complex were 6.7×103 M−1 s−1 and 1.0×10−4 s−1, respectively. The association and dissociation constants of three different immobilized aptamers binding with thrombin were measured and the difference of the dissociation constants obtained was discussed. This work demonstrates that GNPs electrodeposited on GCE used as a platform for the immobilization of the thiolated aptamer can improve the sensitivity of an EIS biosensor for the determination of protein. This work also demonstrates that EIS method is an efficient method for the determination of association and dissociation constants on GNPs modified GCE. [Copyright &y& Elsevier]

Hypospadias is the displacement of the urethral meatus from the tip of the glans to the ventral side of the phallus. During fetal development, SRY, SOX9, WT1, SRD5A2 and AR are important at different stages in the differentiation and development of the male genital system. Mutations in these genes impair masculinization and may be associated with hypospadias. In order to explore these possibilities, we employed polymerase chain reaction and direct sequencing to analyze the coding regions of these five genes in 90 Chinese hypospadias patients. We found a total of 16 different mutations in SRD5A2, AR and WT1 in 24 of these 90 patients. Seven mutations are novel. No mutation was found in SRY or SOX9. SNP V89L found in SRD5A2 was statistically significant between patients and controls. Our results indicated that mutations in SRD5A2, AR and WT1 were associated with hypospadias. In conclusion, mutations are frequently found in genes that control androgen action and metabolism, but are seldom found in genes active in the early phase of sex determination and differentiation. Mutations in AR, SRD5A2 or WT1 seem to be associated not only with hypospadias but also with micropenis.European Journal of Human Genetics (2004) 12, 706-712. doi:10.1038/sj.ejhg.5201232 Published online 21 July 2004 [ABSTRACT FROM AUTHOR]

HPV (Human papilloma virus) is a kind of small double-stranded DNA viruses which is extremely associated with different cancers. The roles HPV plays in the host were gradually identified through the interaction between it (including its early genes) and host RNA. In recent years, increasing numbers of studies in HPV-related cancers have been published showing the relationship between HPV and host RNA. Here, we present a database named HRRD, which contains the regulatory relationship between HPV and RNA (mRNA, miRNA and lncRNA). The information was extracted from 10,761 papers in PubMed (up to December 1st, 2019). In addition, the sequence map of HPV (198 genotypes) is also contained. HRRD was designed as a user-friendly web-based interface for data retrieval. It integrated the information of interaction between HPV and RNA, which reflects the relationship between HPV and host. We hope HRRD will further provide a comprehensive understanding of HPV in carcinogenesis and prognosis. HRRD is freely accessible at www.hmuhrrd.com/HRRD. [ABSTRACT FROM AUTHOR]

• MMP-14 specifically cleaving peptide (CK11) is studied for the first time. • Electrochemical biosensor is designed for detection of MMP-14 for the first time. • MCF-7 cells were first chosen as model to evaluate the application of the biosensor. An electrochemical peptide-based biosensor is described for the determination of matrix metalloproteinase-14 (MMP-14). The method is base on MMP-14-induced cleavage of a specific peptide carrying a ferrocene group (CK11-Fc) placed on a gold electrode. CK11-Fc was first self-assembled on the electrode and the residual surface was blocked with 6-mercapto-1-hexanol. When MMP-14 was present, it specifically cleaves the CK11-Fc. Hence, Fc leaves the electrode and this causes a decrease of the electrochemical signal, best measured at 500 mV (vs. Ag/AgCl) in Tris buffer of pH 7.4. The signal decreases linearly in the 0.2 ng L−1 to 0.9 ng L−1 MMP-14 concentration range, and the detection limit is 0.1 ng L−1 (RSD = 5.7%). The biosensor was successfully applied to the determination of MMP-14 in overexpressed tumor cells (type MCF-7). Conceivably, the work has a wide potential by exploiting such peptide cleavage approaches to construct biosensors for MMPs. [ABSTRACT FROM AUTHOR]

MicroRNA-21 (miRNA-21) is a promising diagnostic biomarker for breast cancer screening and disease progression. A sensitive and selective strategy for the quantitative determination of miRNA-21 is of great significance in the early diagnosis of cancers. Herein, a novel electrogenerated chemiluminescence (ECL) biosensor was designed for the detection of miRNA-21 with dual signal amplification based on isothermal strand-displacement polymerase reaction (ISDPR) and bridge DNA-gold nanoparticles (AuNPs) nanocomposites. The ECL biosensor was fabricated by self-assembling a thiolated capture probe (SH-CP) on the surface of a gold electrode. The target miRNA-21 initiated the phi29 DNA polymerase-mediated ISDPR, which could generate large numbers of single-stranded DNA (assistant DNA) with accurate and comprehensive nucleotide sequences. The assistant DNA was captured by the SH-CP self-assembled on the Au electrode and further hybridized with bridge DNA-AuNPs nanocomposites, more biotins can be captured on the electrode surface. Afterward, a streptavidin-modified Ru (bpy) 3 2+ complex (SA-Ru) was bound to the bridge DNA-AuNPs nanocomposites via a specific interaction between biotin and streptavidin to produce a strong ECL signal. The ECL intensity was logarithmically proportion to the concentration of target miRNA-21 over a range from 0.01 fM to 10,000 fM with a detection limit of 3.2 aM. The proposed ECL biosensor was successfully applied to detect miRNA-21 in total RNA samples extracted from human breast cancer cells, and it showed great potential for early cancer diagnosis based on miRNA as a biomarker. • An ultrasensitive ECL biosensor for the detection of microRNA was developed. • The target triggered the recycling reaction and bridge DNA-AuNPs were utilized to realize efficient signal amplification. • The ECL biosensor can be used for detection of miRNA-21 in total RNA samples extracted from human breast cancer cells. [ABSTRACT FROM AUTHOR]

Background: Human adenoviruses (HAdVs) cause a wide range of diseases. However, the genotype diversity and epidemiological information relating to HAdVs among hospitalized children with respiratory tract infections (RTIs) is limited. Here, we describe the epidemiology and genotype distribution of HAdVs associated with RTIs in Beijing, China. Methods: Nasopharyngeal aspirates (NPA) were collected from hospitalized children with RTIs from April 2017 to March 2018. HAdVs were detected by a TaqMan-based quantitative real-time polymerase chain reaction (qPCR) assay, and the hexon gene was used for phylogenetic analysis. Epidemiological data were analyzed using statistical product and service solutions (SPSS) 21.0 software. Results: HAdV was detected in 72 (5.64%) of the 1276 NPA specimens, with most (86.11%, 62/72) HAdV-positives cases detected among children < 6 years of age. HAdV-B3 (56.06%, 37/66) and HAdV-C2 (19.70%, 13/66) were the most frequent. Of the 72 HAdV-infected cases, 27 (37.50%) were co-infected with other respiratory viruses, most commonly parainfluenza virus (12.50%, 9/72) and rhinovirus (9.72%, 7/72). The log number of viral load ranged from 3.30 to 9.14 copies per mL of NPA, with no significant difference between the HAdV mono- and co-infection groups. The main clinical symptoms in the HAdV-infected patients were fever and cough, and 62 (86.11%, 62/72) were diagnosed with pneumonia. Additionally, HAdVs were detected throughout the year with a higher prevalence in summer. Conclusions: HAdV prevalence is related to age and season. HAdV-B and HAdV-C circulated simultaneously among the hospitalized children with RTIs in Beijing, and HAdV-B type 3 and HAdV-C type 2 were the most frequent. [ABSTRACT FROM AUTHOR]