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Combining surface-initiated, TdT (terminal deoxynucleotidyl transferase) catalyzed enzymatic polymerization (SI-TcEP) with precisely engineered DNA origami nanostructures (DONs) presents an innovative pathway for the generation of stable, polynucleotide brush-functionalized origami nanostructures. We demonstrate that SI-TcEP can site-specifically pattern DONs with brushes containing both natural and non-natural nucleotides. The brush functionalization can be precisely controlled in terms of the location of initiation sites on the origami core and the brush height and composition. Coarse-grained simulations predict the conformation of the brush-functionalized DONs that agree well with the experimentally observed morphologies. We find that polynucleotide brush-functionalization increases the nuclease resistance of DONs significantly, and that this stability can be spatially programmed through the site-specific growth of polynucleotide brushes. The ability to site-specifically decorate DONs with brushes of natural and non-natural nucleotides provides access to a large range of functionalized DON architectures that would allow for further supramolecular assembly, and for potential applications in smart nanoscale delivery systems.

This paper proposes a novel and efficient preparation method for copper-steel bimetallic materials. A transition welding wire for copper-steel gradient connections was designed, and then gas metal arc welding (GMAW) additive manufacturing processes were explored. The effects of the process and material on the microstructure, interface characteristics, and mechanical properties of copper-steel bimetallic materials were systematically studied. The results show that copper-steel bimetallic thin-walled parts can be well formed, which confirms the possibility of the arc additive manufacturing of copper-steel bimetallic parts. With the direct deposition of silicon bronze on the surface of low-alloy steel, the melting unmixed zone (MUZ) appears at the bonding interface of low-alloy steel and silicon bronze, which is prone to produce microcracks, leading to fracture failure of the joint. However, with the addition of the Cu-Ni interlayer, the Fe, Ni, and Cu elements in the bronze interface between the low-alloy steel and silicon were continuously diffused, which improved the nonuniformity of the Fe-rich phase in silicon bronze matrix, and realized the gradient connection at the welding joint. Comparing the tensile properties and microhardness of the joints, it can be found that the tensile strength of the low-alloy steel/Cu-Ni/silicon bronze joint was 66.36 pct higher than that of the alloy steel/silicon bronze joint, which can reach approximately 345.2 MPa and shows a typical ductile fracture mechanism. Additionally, the microhardness of the transition zone in the low-alloy steel/Cu-Ni/silicon bronze joint was more uniform.

Organic, ionic soil stabilizers (OISS) are designed to regulate directly the hydration properties of clay minerals to improve their engineering behavior. The steps involved in this regulation by OISS are unclear and this might limit their application in the current construction environment in China. The purpose of the present study was to reveal the origin of changes in hydration properties of four typical clay samples (with clay mineral contents of >90 wt.%: Na-bentonite, Ca-bentonite, illite, and kaolinite) as affected by OISS. The water-retention capacity of each clay was measured first through liquid limit and water-vapor adsorption tests. Then, the changes in hydration sites, such as exchangeable cations and the surfaces of minerals, were investigated by a series of microscopic measuring and testing techniques. Finally, infrared spectroscopy (IR) and thermal analysis were performed to verify the regulation of hydration properties by OISS. The results suggested that the exchangeable cation and surface changes controlled the regulation of hydration properties. OISS could cause some of the exchangeable cations to become free ions and disrupt the interaction between some cations and water molecules by its long organic chains; thus, the amount of hydrated cations decreased. In addition, the long organic chains covered the mineral surface and weakened its adsorption capacity. Furthermore, the long chains had cementitious qualities, connecting them to the crystalline layer and resulting in more aggregated clay particles and a smaller specific surface area (SSA). With the decrease in the number of cations and in the SSA by OISS, the hydration of the four clay samples decreased, especially in the case of bentonite.

In this study, a rapid and sensitive analytical method has been developed to detect tetracycline hydrochloride (TC) using manganese-doped carbon dots (Mn-CDs) prepared by one-step hydrothermal procedure using 1-(2-pyridinylazo)-2-naohthalenol (PAN) and MnCl2 as precursor reagents. The obtained Mn-CDs showed an ultraviolet emission at 360 nm with an excitation wavelength of 300 nm. TC has a strong characteristic absorption peak at 356 nm, which has a large spectral overlap with the emission band of the Mn-CDs. The fluorescence intensity (FI) of Mn-CDs at 360 nm is linearly quenched within the TC concentration range of 0.1-200 µM. The developed assay for the detection of TC was based on an inner filter effect (IFE) mechanism and is rapid, sensitive, and was successfully applied for the determination of TC in different poultry meat samples with satisfactory results.

Electrocatalysts derived from porphyrinic metal-organic frameworks (MOFs) have exhibited very promising electrochemical performances toward oxygen reduction reaction (ORR). Nevertheless, porphyrinic MOFs have been limited to skeleton- or the pore-modified ones mostly by Fe porphyrin (FeP), which only provide insufficient ORR active sites. Herein, we report controlled synthesis of PCN-222 decorated by both pore-filling Hemin and skeletal iron(III) meso-tetra(4-carboxyphenyl) porphyrin (Fe[Formula: see text]TCPP) that partially substitutes original backbone TCPP. Subsequent pyrolysis of the composite PCN-222 led to the synthesis of nanorod electrocatalysts with atomically dispersed Fe-N-C sites, which exhibit efficient activity and durability toward ORR in both alkaline and acidic media. Moreover, it appears that the atomically dispersed Fe-N-C sites might possess a distorted octahedral configuration of (O/N)2-Fe[Formula: see text]-N4 as evidenced by extended X-ray absorption fine structure spectra (EXAFS), aberration-corrected high-angle annular dark-field scanning transmission electron microscope (HAADF-STEM), and X-ray photoelectron spectroscopy (XPS). To the best of our knowledge, controlled modification to both the skeleton and the pore of MOFs with FeP for the synthesis of Fe-N-C electrocatalysts has not been reported prior to this study. This study offers a new avenue to manipulate the density of Fe-N-C sites of electrocatalysts, which may be applied to other composite MOFs with various functionalities.

Summary Background & aims Although disorders of iron metabolism are among the most common diseases and dietary intakes of vitamin A, B2, B6, C, E, and folic acid are known to affect the absorption or oxidation of iron, limited data are available on the association of dietary iron and these vitamins with mortality in the same population. Specifically, the holistic dietary vitamins intake and its combined effect with iron on mortality are unclear. The purpose of this study was to evaluate the association of dietary iron, holistic dietary vitamins, and their interactive effect with total and cause-specific mortality. Methods We evaluated the effects of dietary total/heme/non-heme iron, vitamins, and their interaction on all-cause/cardiovascular disease (CVD)/cancer mortality among 14,826 US adults in the National Health and Nutrition Examination Survey (NHANES), a population-based nationally representative study. We developed a vitamin score to represent the holistic dietary intakes of vitamin A, B2, B6, C, E, and folic acid. Results A total of 2154 deaths occurred during a median follow-up of 9.3 years. Results from multivariate Cox proportional hazards models showed that higher vitamin score was associated lower risk of all-cause mortality (P-trend = 0.027). Negative interactions between dietary heme iron and vitamin score were observed on all-cause/CVD mortality. Dietary higher vitamins combined with lower heme iron was associated with lower risk of all-cause and CVD mortality (HR (95% confidence intervals (CIs)): 0.80 (0.64–0.98) and 0.55 (0.31–0.98), respectively). Higher dietary vitamins combined with higher total/non-heme iron was associated with lower risk of CVD mortality (HR (95%CIs): 0.69 (0.48–0.99) and 0.70 (0.48–0.99), respectively). These results remained significant even excluding participants with iron supplementation. Conclusion Our findings suggested that interactive effect of holistic dietary vitamins and iron play a protective role in decreasing all-cause and CVD mortality. Future studies, including cohort studies and clinical trials, are necessary to confirm these findings.

The present paper dealt with characterizing microstructure and mechanical properties of the dissimilar weldment between stainless steel and copper obtained by gas metal arc welding using HS201 filler material. The results showed that the copper/weld interface was free of any defects, while the stainless steel/weld interface consisted of a melted unmixed zone with inhomogeneous distribution of composition. The weld showed a hybrid microstructure, which contained significant amount of steel globules and dendrites with different sizes. The hardness distribution of the weld was inhomogeneous, and an obvious reduction in microhardness of the heat-affected zone of copper was observed compared to that of the base metal of copper. Furthermore, all tensile specimens fractured at the heat-affected zone of copper, and the average tensile strength of welded joint reached 209.5 MPa.

Suppressing the anionic mobility in solid polymer electrolytes (SPEs) is crucial to mitigate the ionic conductivity and internal cell polarization, thus upgrading the stability and cycle life of rechargeable lithium-ion batteries (LIBs). Now, a series of novel conducting solid polymer electrolytes (CSPEs) with a zwitterionic structure comprising TEOS which was grafted to nitrogen-centered cations connected to hydrophilic sulfonate and carboxylate groups were used as SPEs in LIBs. The quaternized 1,8-diaminonaphthalene polyvinylidene difluoride lithium-ion conducting electrolyte (DN-PF-LCP) as an SPE component in LIBs achieves outstanding ionic conductivity (8.69 × 10−4 S cm−1), a sufficient capacity of 136 mA h g−1 with a decent capacity retention of 96% at a current rate of 0.3C over 200 cycles at 25 °C, and superior thermo-stability (∼420 °C). The zwitterionic structure of the DN-PF-LCP CSPE provides strong molecular interactions and efficiently facilitates the disintegration of Li+ ions, thus stimulating the mobility of Li+ ions within the CSPE and enhancing the Li+ ion conduction properties. The hydrogen bonding and ion–dipole interactions in the DN-PF-LCP CSPE provide nanosized self-agglomeration of anions and provide interaction between anions and their structurally homologous matrix, thus impeding the mobility of anions and lithium dendritic growth. These outstanding characteristics of DN-PF-LCP make it promising as a CSPE for LIBs.

A fluid inclusion petrographic and microthermometric study was performed on the sandstones gathered from the Yanchang Formation, Jiyuan area of the Ordos Basin. Four types of fluid inclusions in quartz can be recognized based on the location they entrapped. The petrographic characteristics indicate that fluid inclusions in quartz overgrowth and quartz fissuring-I were trapped earlier than that in quartz fissuring-IIa and fissuring-IIb. The homogenization temperature values of the earlier fluid inclusions aggregate around 80 to 90°C; exclusively, it is slightly higher in Chang 6 member, which approaches 95°C. The later fluid inclusions demonstrate high homogenization temperatures, which range from 100 to 115°C, and the temperatures are slightly higher in Chang 9 member. The calculated salinities show differences between each member, including their regression characteristics with burial depth. Combining with the vitrinite reflection data, the sequence and parameters of fluid inclusions indicate that the thermal history of the Yanchang formation mostly relied on burial. Salinity changes were associated with fluid-rock interaction or fluid interruption. Hydrocarbon contained fluid inclusions imply that hydrocarbon generation and migration occurred in the Early Cretaceous. The occurrence of late fluid inclusions implied that quartz cement is a reservoir porosity-loose factor.

Design and synthesis of highly active and durable electrocatalysts toward oxygen reduction reaction (ORR) is of particular importance for proton exchange membrane fuel cells (PEMFCs), yet remains a grand challenge. Herein, we report the deposition of iron (III) porphyrin (FeP) on house-made Pt/C by rotary evaporation of the mixture of FeP and house-made Pt/C dispersed in chloroform, followed by pyrolysis at 650 °C in argon atmosphere. This approach led to the synthesis of new non-precious metal electrocatalyst (NPME)-Pt/C composites (Pt/C–FeP) with an average nanoparticle diameter of 3.1 ± 1.5 nm without aggregation. According to X-ray photoelectron spectroscopy (XPS), the binding energy of Pt 4f7/2 became larger due to the presence of pyrolyzed FeP. In addition, the electrochemically active surface area (ECSA) of Pt/C–FeP-650 is 65 m2/g less than that of house-made Pt/C (80.2 m2/g). This implies that the pyrolyzed FeP may have partially covered the surface of Pt nanoparticles and thus lowering the ECSA. Interestingly, the mass activity (MA) of Pt/C–FeP turns out to be 349.0 mA/mgPt @0.9 V vs. RHE, which is 2.6 times and 1.5 times of house-made Pt/C and commercial Pt/C, respectively. It is speculated that the electronic interaction and possible synergy between Pt and pyrolyzed FeP as NPME might have contributed to the ORR activity improvement despite of partial loss of ECSA. During accelerated durability tests (ADTs), the MA of Pt/C–FeP-650 degrades 64.3% inferior to commercial Pt/C (52.2%). The main reason likely arises from the degradation of pyrolyzed FeP, which is a bottleneck problem confronting NPMEs.

Mesenchymal stem cell (MSCs)‐based therapies have shown a promised result for intervertebral disc degeneration (IVDD) treatment. However, its molecular mechanisms remain unclear. Exosomes involve cell‐cell communication via transference of its contents among different cells, and the present potential effect on cell death regulation. This study aimed to investigate the role of MSCs‐derived exosomes on IVDD formation. Here, we first found the NLRP3‐mediated nucleus pulposus cell (NP cell) pyroptosis was activated in the IVDD mice model and lipopolysaccharide (LPS)‐induced model. However, MSCs treatment could inhibit NP cell pyroptosis in vitro. We then isolated MSCs‐derived exosomes by differential centrifugation and identified the characteristics. Secondly, we investigated the function of MSCs‐derived exosomes on LPS‐induced NP cell pyroptosis. Finally, we presented evidence that MSCs‐derived exosomal miR‐410 was a crucial regulator of pyroptosis. Results showed that MSCs‐derived exosomes play an anti‐pyroptosis role by suppressing the NLRP3 pathway. Moreover, it suggested that this effect was attributed to miR‐410, which was derived from MSCs‐exosomes and could directly bind to NLRP3mRNA. In conclusion, for the first time, we demonstrated that MSCs‐exosome treatment may inhibit pyroptosis and could be a promising therapeutic strategy for IVDD.

Commonly used aquatic feed naturally contains low-level or no hydroxyproline (Hyp). This study was conducted to evaluate the effects of dietary Hyp inclusion on growth performance, body composition, amino acid profiles, blood biochemistry, and the expression of target of rapamycin (TOR) pathway-related genes in juvenile Nibea diacanthus. Fish with similar size (initial body weight, 133.00 ± 2.14 g) were fed six isonitrogenous and isolipidic practical diets supplemented with graded levels of Hyp (0, 5, 10, 15, 20, and 25 g kg-1 of dry matter) for 8 weeks. The results indicated that growth performance and feed utilization were improved with increased levels of dietary Hyp (P < 0.05), and the optimum amount of dietary Hyp estimated from SGR as 16.6 g kg-1. The crude protein of whole body and swim bladder and the amino acid composition of muscle and swim bladder were significantly (P < 0.05) affected by the addition of dietary Hyp, which reflects the important role of feed composition in animal body composition. In addition, the expression levels of mammalian target of rapamycin (TOR) and ribosomal protein S6 kinase1 (S6K1) genes in the liver, muscle, and swim bladder increased with increasing Hyp content of diets, while the mRNA expression level of eukaryotic translation initiation factor 4E-binding protein (4E-BP) gene in these tissues decreased. These results indicated that Hyp improved fish growth and the ability to synthesize proteins, most likely through the TOR pathway. It is suggested that dietary Hyp supplementation is particularly necessary for application in aquatic feed.

In petroleum science, asphaltenes are well-known as the most refractory fraction of crude oil and remain infamous for problems in production, transportation, and refining processes. Hence, they hav...

DArk Matter Particle Explorer (DAMPE), a satel- lite-based cosmic-ray (CR) and gamma-ray measurement experiment, relies on its calorimeter to measure the energy of incident particles. The calorimeter adopts crystals of bismuth germanium oxide (BGO) as scintillating material, and it is designed to aim for measurements of energy ranging from 50 GeV to 100 TeV in the case of a CR nucleus. This article concerns the response of the BGO calorimeter to nucleus-type CRs. CRs with very low energy can rarely reach the detector due to the Earth’s magnetic field. A cutoff on lower energy can be observed in the energy spectrum. In this article, the cutoff is used to study the response of the calorimeter. Carbon, neon, silicon, and iron are analyzed separately in comparison with Monte Carlo simulations by Geant4.

The DArk Matter Particle Explorer (DAMPE) is a satellite-borne, calorimetric-type, high-energy-resolution detector for the precise measurement of high-energy electrons, gamma rays, and nuclei from deep space. The DAMPE electromagnetic calorimeter consists of bismuth germanate (BGO) crystals that can measure incident hadron energies from 50 GeV to 100 TeV. For an inorganic scintillator, such as BGO, the nonlinear fluorescence response when measuring ions contributes to the difference between the experimental data and Monte Carlo simulations. This article reports the BGO quenching nonlinearity occurring in the DAMPE experiment. The ionization energy response of BGO to several kinds of ions lighter than iron is investigated by conducting beam tests and analyzing flight data. We compare the scintillator output with the energy loss according to GEANT4 simulations and determine the quenching parameters. The combined result of beam test and flight experiment shows that the quenching effect strongly depends on the density of the ionization energy loss.

Amino acids can act as signaling molecules in protein synthesis and animal growth by regulating several genes in the target of rapamycin (TOR) pathway. An 8-week feeding trial was conducted to examine the effects of dietary proline on growth performance, body composition, amino acid profiles, blood-biochemistry and expression of TOR pathway-related genes in juvenile Nibea diacanthus. Fish (450 juvenile N. diacanthus) were assigned to six dietary proline supplementation groups (0, 2.5, 5, 7.5, 10 and 12.5 g kg−1 of dry diet). The results revealed that the growth performance and feed utilization of N. diacanthus were not significantly improved with dietary proline level (P > 0.05). Whole-body crude protein and some amino acids in muscle tissue were significantly (P

Vanadyl petroporphyrins purified from a North American petroleum vacuum residue are used in experiments probing the interfacial phenomena of the petroporphyrins as well as asphaltene-petroporphyrin...

In this work, wide-spectrum Mg- and Ga co-doped ZnO (MGZO) transparent conductive films are developed via reactive plasma deposition (RPD) technique with soft thin-film growth process. MGZO film with a work function of ~4.36 eV can be achieved within 12 min without any intentional substrate-heating treatment. 480nm-thickness MGZO film exhibits a low resistivity of ~9.9x10-4 Ωcm and a high transmittance of ~82.6% in the UV-VIS-NIR region (λ approximately 400 nm-1200 nm). XRD spectra show that MGZO films exhibit (103) preferred orientation as the film thickness increases. A silicon hetero-junction (SHJ) solar cell based on 480nm-thick MGZO at the front side is completed. Excellent continuity of MGZO film is proven by the cross-sectional SEM images and there are no cracks and pinholes on the top and bottom of the c-Si pyramids. Further efficiency improvements are achieved using an ultra-thin SnOx buffer layer with an ameliorated p-a-Si:H/TCO interface. Also, a silicon hetero-junction (SHJ) solar cell using M...

Aggregation-induced emission (AIE) probes that can be triggered by enzymatic activity are sought for applications across the life sciences. The compound 2-(2-hydroxyphenyl)benzothiazole (HBT) is non-fluorescent in solution but exhibits AIE. To adapt HBT for potential clinical applications, two phosphoester derivatives (1 and 2) were prepared. For extension to molecular brachytherapy (delivery of a radionuclide), one phosphoester derivative (3) was prepared wherein a bromine atom is incorporated as a site for subsequent radioiodide substitution. Each probe 1–3 requires phosphatase action to engender AIE. For specificity in diagnostic and therapeutic applications, a heterologous (i.e., foreign to humans) enzyme was sought for conversion of 1–3 from aqueous-soluble to aqueous-insoluble form. Here, an archaeal phosphodiesterase PDE-MJ0936 (wild-type) was systematically engineered for activity toward 1–3. PDE-MJ0936 is a hyperthermal enzyme (activity at 70 °C and pH 9.8) and exists as a dimer, which together limit life science applications. Ten PDE mutants were engineered by site-directed mutagenesis to achieve a monomeric structure, wider substrate scope, and elastic substrate docking under physiological conditions. Among the mutants, PDE-C141D exhibited efficient activity towards bis(4-nitrophenyl)phosphate (Km = 0.28 mM, kcat = 3.0 s−1 and kcat/Km = 1.1 × 104 M−1 s−1) and efficiently hydrolyzed 3 at 37 °C and pH 7.0, conditions under which PDE-MJ0936 is silent. The substrates 1–3 are relatively resistant to alkaline phosphatase, PDE-MJ0936 and fetal bovine serum. The development of enzymatically triggered substrates and the complementary heterologous enzymes may support diverse applications in the life sciences.

Background Insulin controls hyperglycemia caused by diabetes, and virtually all treatments require exogenous insulin. However, the product’s extensive post-translational modifications have hindered the manufacture of recombinant insulin. Result Here we report a novel production method for a monomeric B22Asp desB30 insulin analog (B22D desB30 insulin). Its precursor, DPIP, is fused to an N-terminal chitin-binding domain and intein self-cleavage tag. The fusion protein is expressed and purified from E. coli and immobilized on chitin resins. DPIP is then released using an optimized pH shift and converted to mature insulin via trypsin digest. The resulting product appears monomeric, > 90% pure and devoid of any exogenous enzyme. Conclusion Thus, biologically active insulin analog can be efficiently produced in bacteria and potentially applicable in the treatment of human diabetes.

We report the pyrolysis of uniform nanocapsules of ironIII porphyrin metal–organic frameworks (MOF PCN-222), evolving into carambola-like electrocatalysts enclosed by six concave facets. The nanocarambolas merely comprise of atomically dispersed Fe sites and exhibit efficient activity and durability toward the oxygen reduction reaction (ORR) relative to commercial Pt/C.

An “A2BC”-type bioconjugatable compound (1) that enables enzymatically triggered cross-linking chemistry has been designed and synthesized. The compound contains two indoxyl-glucoside units (A units), which upon action of a glucosidase undergo oxidative dimerization to form a water-insoluble indigoid dye. The other two moieties are azide (B, for click chemistry) and (C) a triazine-chloride or a coumarin dye; the former enables substitution with a nucleophile while the latter provides for ratiometric sensing of the extent of indigoid dye formation. A 7-component building block synthesis relies on successive substitution of 2 cyanuric chloride (2,4,6-trichloro-1,3,5-triazine) molecules with 5 other constituents (2A, B, C, and a piperazine–sulfobetaine moiety); the latter bear oligoethylene glycol (i.e., PEG) or aminoalkyl tethers. The substitution reactions of cyanuric chloride proceed almost entirely at room temperature with control achieved by the order of nucleophile reactivity (aliphatic amine > phenol ≫ aliphatic alcohol) and the nature of a chosen base. Treatment of 1 with glucosidase under physiological conditions in aqueous solution gave an indigoid solution and a precipitate (∼1 : 9 ratio) that were characterized by absorption spectrometry (including multicomponent analysis), dynamic light-scattering spectroscopy, and optical microscopy. Ratiometric absorption of the integral coumarin dye with the indigoid scaffold showed a low yield (3%) of oligomerization, which suggests future molecular designs might employ longer linkers and/or substituents with greater water solubility.

Hydroxyproline (Hyp) may play an important role in collagen metabolism, as it is almost exclusively found in collagen. To examine this possibility, a 56‐day feeding trial was conducted to evaluate the effect of graded supplementaries of Hyp (0, 2.5, 5, 7.5, 10 and 12.5 g/kg dry diet weight) on growth performance, feed utilization, biochemical composition and collagen synthesis of chu's croaker, Nibea coibor (13.6 ± 0.28 g). The growth performance and feed utilization were improved with increased levels of dietary Hyp, reaching a maximum at 5 g/kg (diet H2) followed by a slight decrease. Polynomial regression analysis showed that the maximum specific growth rate (SGR) was attained at 7.177 g/kg dietary Hyp. Increasing levels of Hyp did not affect body composition of juvenile Nibea coibor. However, dietary Hyp supplementation significantly affected the levels of Leu, Ile, Met, Lys, Ser, Glu and Pro in muscle and the levels of Met, Lys, Glu, Pro and Gly in swim bladder. The serum calcium (SC) level decreased significantly with increasing levels of dietary Hyp. However, the triglycerides (TG) and total cholesterol (T‐CH) levels in serum and liver were relatively stable. Importantly, the acid‐soluble collagen (ASC) and total collagen (TC) levels in swim bladder increased significantly initially and then decreased after reaching a maximum. Polynomial regression analysis revealed that the maximum TC level in swim bladder was attained at 9.736 g/kg of dietary Hyp. Collectively, these results suggest that the appropriate provision of hydroxyproline is essential for maximal collagen synthesis and growth.

Aims Soil organic carbon (SOC) plays an important role in improving soil quality, however how long-term fertilization influences SOC and contrasting active carbon (AC) and passive C (PC) pools at large scale remains unclear. The aim of this study was to examine the effect of long-term fertilization on SOC, including AC and PC, across four typical croplands in China and to explore the potential relationships and mechanism. Methods We assessed the effect of different fertilization (standard and 1.5 × standard of inorganic fertilizer (NPK) with or without manure (M), with a control for comparison) at soil depths (0-20 cm, 20-40 cm, 40-60 cm) on SOC, AC and PC. Results We found that SOC, AC and PC increased in the order Control < NPK < NPKM < 1.5NPKM. 1.5NPKM resulted in a significant increase in SOC, AC and PC, of 76.3%, 53.0% and 108.5% respectively across the soil profile (0-60 cm) compared with Control. The response ratio of PC to long-term fertilization was 2.1 times greater than that of AC across four sites on average. In addition, Clay was identified as the most important factor in explaining the response of AC and PC to different fertilization application, respectively. Conclusions Long-term fertilization enhanced both AC and PC, but the greater response of PC suggests that fertilization application could enhance the stability of carbon and thus the potential of cropland for soil carbon accumulation.

To strengthen the management of maize varieties and the protection of intellectual property rights to new varieties, we constructed a comprehensive single nucleotide polymorphism (SNP)-DNA standard fingerprint database of 20,075 materials covering nationally and provincially approved maize hybrid lines, hybridized combinations, and inbred lines. The database was based on 200 core SNPs selected from 60 K SNPs distributed in intragenic regions, including 106 (53.0%) located in exons. Average minor allele frequencies (MAF) of the 200 SNPs in 6755 maize hybrids, 7837 hybridized combinations, and 3478 inbred lines were 0.385, 0.350, and 0.378, respectively, with corresponding average polymorphism information content (PIC) values of 0.354, 0.335, and 0.351. Heterozygous genotype frequencies of maize hybrids, hybridized combinations, and inbred lines averaged 0.48, 0.47, and 0.012, respectively. The number of different loci in the three different maize groups ranged from one up to 164, 160, and 140, respectively. The percentage of different SNPs within 5% (the number of difference SNPs is less than 10) accounted for 0.013%, 0.011%, and 0.030% among pairwise comparisons of samples within hybrid lines, hybridized combinations and inbred lines, respectively. Genetic distances between varieties based on the 200 core SNPs were highly correlated with those obtained using 60 K SNPs, with a correlation coefficient of 0.82 and 0.87 in in inbred and hybrid lines, respectively. The maize SNP-DNA fingerprint database established in this study can play an important role in variety authentication, purity determination and the protection of variety rights, thereby providing reliable, comprehensive data support for use in the seed industry.

Small-angle neutron scattering (SANS) is used to characterize the aggregation of pure vanadyl petroporphyrins (VOPPs), as well as of asphaltenes mixed with either VOPPs or synthetic porphyrins. Sim...

Nanoscale zero-valent iron (nZVI) particles supported on a porous, semi-interpenetrating (semi-IPN), temperature-sensitive composite hydrogel (PNIPAm-PHEMA). nZVI@PNIPAm-PHEMA, was successfully synthesized and characterized by FT-IR, SEM, EDS, XRD and the weighing method. The loading of nZVI was 0.1548 ± 0.0015 g/g and the particle size was 30–100 nm. NZVI was uniformly dispersed on the pore walls inside the PNIPAm-PHEMA. Because of the well-dispersed nZVI, the highly porous structure, and the synergistic effect of PNIPAm-PHEMA, nZVI@PNIPAm-PHEMA showed excellent reductive activity and wide pH applicability. 95% of 4-NP in 100 mL of 400 mg/L 4-NP solution with initial pH 3.0–9.0 could be completely reduced into 4-AP by about 0.0548 g of fresh supported nZVI at 18–25 °C under stirring (110 r/min) within 45 min reaction time. A greater than 99% 4-NP degradation ratio was obtained when the initial pH was 5.0–9.0. The reduction of 4-NP by nZVI@PNIPAm-PHEMA was in agreement with the pseudo-first-order kinetics model with Kobs values of 0.0885–0.101 min−1. NZVI@PNIPAm-PHEMA was able to be recycled, and about 85% degradation ratio of 4-NP was obtained after its sixth reuse cycle. According to the temperature sensitivity of PNIPAm-PHEMA, nZVI@PNIPAm-PHEMA exhibited very good storage stability, and about 88.9% degradation ratio of 4-NP was obtained after its storage for 30 days. The hybrid reducer was highly efficient for the reduction of 2-NP, 3-NP, 2-chloro-4-nitrophenol and 2-chloro-4-nitrophenol. Our results suggest that PNIPAm-PHEMA could be a good potential carrier, with nZVI@PNIPAm-PHEMA having potential value in the application of reductive degradation of nitrophenol pollutants.

Background: Atherosclerosis is determined as a chronic, complicated disease, and arterial walls were mainly composed of vascular smooth muscle cells (VSMCs). microRNAs (miRNAs) have been consistently demonstrated to be involved in VSMCs, and miR-33a-5p was reported concerning many biological functions of cells. However, the role of miR-33a-5p during atherosclerosis still unclear. Methods: In present study, human VSMCs were treated with platelet-derived growth factorbb (PDGF-bb) after transfection. The miR-33a-5p and S1PR1 expression levels were determined by qRT-PCR and/or Western blot assays. VSMCs proliferation, invasion and migration were measured by CCK-8, transwell and wound healing assays, respectively. Luciferase reporter assay was employed to validate the direct targeting of S1PR1 by miR-33a-5p. Results: The results showed that PDGF-bb treated after 24 h could promote cell proliferation and regulate the expression of miR-33a-5p and S1PR1 in VSMCs. Overexpression of miR-33a-5p inhibited proliferation, invasion and migration in PDGF-bb treated VSMCs. Furthermore, we proved that miR-33a-5p could directly target S1PR1, and miR-33a-5p mimic suppressed the expression of S1PR1 in PDGF-bb treated VSMCs. Conclusions: The results suggested that miR-33a-5p could inhibit the proliferation, invasion and migration of VSMCs via suppressed the expression of S1PR1. miR-33a-5p/S1PR1 axis may represent a potential therapeutic strategy to improve atherosclerosis.

Parkinson's disease (PD) is a common neurodegenerative disease, featured by motor deficits and non-motor symptoms such as cognitive impairment, and malfunction of gamma-aminobutyric acid (GABA) mediated inhibitory transmission plays an important role in PD pathogenesis. The ginsenoside Rb1 molecule, a major constituent of the extract from the Ginseng root, has been demonstrated to ameliorate motor deficits and prevent dopaminergic neuron death in PD. However, whether Rb1 can regulate GABAergic transmission in PD-associated deficits and its underlying mechanisms are still unclear. In this study, we explored the effects of Rb1 on the GABAergic synaptic transmission in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. We demonstrated that Rb1 can bind with GABAARα1 and increase its expression in the SH-SY5Y cells and in the prefrontal cortex (PFC) of MPTP model in vitro and in vivo. Furthermore, Rb1 can promote prefrontal cortical GABA level and GABAergic transmission in MPTP-treated mice. We also revealed that Rb1 may suppress presynaptic GABABR1 to enhance GABA release and GABAA receptor-mediated inhibitory transmission. In addition, Rb1 attenuated MPTP-induced dysfunctional gait dynamic and cognitive impairment, and this neuroprotective mechanism possibly involved regulating prefrontal cortical GABAergic transmission. Thus, Rb1 may serve as a potential drug candidate for the treatment of PD.

Determination of the molecular structures of petroporphyrins has been crucial to understand the diagenetic pathways and maturation of petroleum. However, these studies have been hampered by their structural complexity and the challenges associated with their isolation. In comparison to the skeletal macrocyclic structures, much less is known about the substitutions, which are more sensitive to the maturation and diagenesis pathways. While these isolated vanadyl petroporphyrins largely consist of etioporphyrin and deoxophylloerythroetioporphyrin as expected, surprisingly, we find evidence that one or a few β hydrogens are present in petroporphyrins of low carbon numbers using a combination of ultraviolet-visible spectroscopy, Fourier transform ion cyclotron resonance mass spectrometry, and non-contact atomic force microscopy. Petroporphyrins with β hydrogens were not anticipated on the basis of their biological precursors. The data support dealkylation under catagenesis but not transalkylation or random alkylation of the β and meso positions, despite the fact that more complex porphyrin structures are formed.

Heteroatoms are essential for functional groups in organic structures and are complementary to hydrocarbon molecules in reactivities and properties. However, it is still a challenge to quickly iden...

The DArk Matter Particle Explorer (DAMPE), which is a Chinese space telescope for the precise measurement of high-energy electrons, gamma rays, and nuclei from deep space, was successfully launched on December 17, 2015. The DAMPE electromagnetic calorimeter made of bismuth germanium oxide (BGO) crystals can measure incident hadron energies from 50 GeV to 100 TeV. The calorimeter was tested with ion beams at CERN in 2015. The energy responses to ions from helium to argon are investigated. The result is reproduced by a Monte Carlo simulation based on Geant4 with two physics process models. It shows that the simulation results of a beam test are independent of the physics models adopted. Additionally, quenching effects of the BGO crystal on the ions are observed with this beam test. The quenching attenuations increase with the atomic number and were approximately 7% for boron and 40% for argon.

The cyanobacterial culture HT-58-2, composed of a filamentous cyanobacterium and accompanying community bacteria, produces chlorophyll a as well as the tetrapyrrole macrocycles known as tolyporphins. Almost all known tolyporphins (A–M except K) contain a dioxobacteriochlorin chromophore and exhibit an absorption spectrum somewhat similar to that of chlorophyll a. Here, hyperspectral confocal fluorescence microscopy was employed to noninvasively probe the locale of tolyporphins within live cells under various growth conditions (media, illumination, culture age). Cultures grown in nitrate-depleted media (BG-110 vs. nitrate-rich, BG-11) are known to increase the production of tolyporphins by orders of magnitude (rivaling that of chlorophyll a) over a period of 30–45 days. Multivariate curve resolution (MCR) was applied to an image set containing images from each condition to obtain pure component spectra of the endogenous pigments. The relative abundances of these components were then calculated for individual pixels in each image in the entire set, and 3D-volume renderings were obtained. At 30 days in media with or without nitrate, the chlorophyll a and phycobilisomes (combined phycocyanin and phycobilin components) co-localize in the filament outer cytoplasmic region. Tolyporphins localize in a distinct peripheral pattern in cells grown in BG-110 versus a diffuse pattern (mimicking the chlorophyll a localization) upon growth in BG-11. In BG-110, distinct puncta of tolyporphins were commonly found at the septa between cells and at the end of filaments. This work quantifies the relative abundance and envelope localization of tolyporphins in single cells, and illustrates the ability to identify novel tetrapyrroles in the presence of chlorophyll a in a photosynthetic microorganism within a non-axenic culture.

RNA elements such as catalytic RNA, riboswitch, microRNA, and long non-coding RNA perform a major role in cellular processes. A complete understanding of cellular processes is impossible without knowing the structure-function relationship of participating RNA molecules that ultimately requires large quantities of pure RNAs. Thus, structural/functional analyses of emerging RNAs necessitate revised protocols for improved RNA quantity and quality. Here we present a modified in vitro transcription protocol to enhance ribozyme cleaving efficiency and RNA yield by working on two variables, i.e., incubation temperature and limiting GTPs. Following an improved RNA synthesis, the target RNA is purified from transcription mixture components through denaturing size-exclusion chromatography. The protocol confirms that cyclic elevated incubation temperatures during transcription and increased concentrations of GTPs improve the production rate of RNA. Our modified in vitro transcription method improves the ribozyme cleaving efficiency and targets RNA yield by four- to fivefold that can benefit almost any RNA-related study from protein-RNA interaction analysis to crystallography.

A host of vanadyl petroporphyrins containing multiple sulfur and oxygen atoms and their combinations (CcH2c+ZN4VOoSs, s = 0–3, o = 1–4, Z = −28 to −70) in a vacuum residue were observed by a combination of extensive enrichment of petroporphyrins and detailed analysis using ultra-high resolution Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). Many of the petroporphyrin species are being observed for the very first time. The patterns of the porphyrin type distribution revealed dramatic differences in the sulfur and oxygen atom incorporations and their impact on Z number. For each sulfur atom addition, the average Z-number was reduced by ∼4–7, implying that sulfur may be incorporated by the additions of thiophene or cyclic thiophene moieties. In contrast, oxygen addition had little to no impact on the average Z number, implying that oxygen may be incorporated as carbonyl or hydroxyl groups. The porphyrin-based structures were found to contain as many as 8 aromatic rings in addition to the porphyrin macrocycle. Petroporphyrins in longer wavelength absorption fractions were found to contain more heteroatoms and more condensed aromatic rings.

Developing low-mobility visible light photoinitiators (PIs) will open new application fields for photopolymerization. In this paper, a polymerizable visible light PI (PBDA) containing acryloyl groups based on a benzylidene cyclopentanone moiety was synthesized and characterized by 1H-NMR, 13C-NMR, UV-Vis spectrum and HR-MS. Its linear absorption appears in the visible region (400–530 nm) and overlaps very well with the emission spectrum of a common blue light source. Under the irradiation of a 473 nm diode laser, the polymerization of commercial acrylate monomers can be induced directly by PBDA. Due to the existence of acryloyl groups, PBDA can be linked into the polymer networks, which decreases its migration in the matrix and improves the biosafety of the end-products. Furthermore, PBDA presents a large two-photon absorption cross-section around 800 nm based on its D–π–A–π–D conjugated structure. 3D microstructures were fabricated using the formulation containing PBDA as PI by two-photon photopolymerization.

Background He-Chan Pian (HCP), a traditional Chinese medicinal formula, shows promising efficacy for the treatment of lung cancer. Purpose Gremlin (GREM1) plays an important role in gastrointestinal tumor metastasis; however, little is known about its role in lung cancer. We determined the mechanism underlying the protective effect of HCP against metastasis in a mouse model of non-small cell lung cancer (NSCLC) and demonstrated the role of GREM1. Methods Ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS) was used to analyze the herbal components and metabolites from the serum of HCP-treated mice. The tumor, liver, and kidney were examined histologically, and the antitumor effects and toxicity of HCP were evaluated. Levels of epithelial-mesenchymal transition (EMT)-associated transcription factors were measured using western blotting in tumors from five groups (i.e., model, HCP [L], HCP [M], HCP [H], and positive control [cisplatin, DDP]). Differentially expressed proteins and genes were identified using protein chip and sequencing analyzes, respectively. Short hairpin RNAs and overexpression plasmids were introduced into cells to evaluate the effects of GREM1. To evaluate proliferation, migration, and invasion, the expression levels of proteins involved in the Rap1 pathway and EMT were measured in vitro. Xenograft tumors with overexpression-GREM1 (OE-GREM1) in A549 cells were examined for cell proliferation. A dual-luciferase assay was performed to verify the direct interaction of GREM1 with miR-205-5p in lung cancer. Results Thirty-six ingredients and bioactive constituents detected in the serum of HCP-treated mice were identified as the key compounds involved in the inhibition of tumor growth. Animal experiments revealed that HCP significantly decreased tumor volumes and had no adverse effects on the liver or kidney or side effects. GREM1 upregulation was closely related to tumor metastasis and was regulated by miR-205-5p, as confirmed using a dual-luciferase reporter assay. OE-GREM1 promoted A549 cell migration and invasion, promoted EMT, and increased the expression of Rap1 pathway intermediaries, whereas shGREM1 had the opposite effects. Furthermore, the effects of OE-GREM1 on proliferation in the A549 xenograft mouse model were attenuated, although HCP has an inhibitory effect on tumors. Conclusion Our results suggest that HCP contributes to the inhibition of NSCLC metastasis via the Gremlin/Rap1 signaling pathway regulated by miR-205-5p.

Bond breaking and forming are essential components of chemical reactions. Recently, the structure and formation of covalent bonds in single molecules have been studied by non-contact atomic force microscopy (AFM). Here, we report the details of a single dative bond breaking process using non-contact AFM. The dative bond between carbon monoxide and ferrous phthalocyanine was ruptured via mechanical forces applied by atomic force microscope tips; the process was quantitatively measured and characterized both experimentally and via quantum-based simulations. Our results show that the bond can be ruptured either by applying an attractive force of ~150 pN or by a repulsive force of ~220 pN with a significant contribution of shear forces, accompanied by changes of the spin state of the system. Our combined experimental and computational studies provide a deeper understanding of the chemical bond breaking process., Controlled breaking of a chemical bond by mechanical forces can provide key insight into reaction mechanisms. Here the authors, using atomic force microscopy and computations, measure the forces involved in breaking a single dative bond between a CO molecule and a ferrous phthalocyanine complex.

Folliculin (FLCN) is a tumor suppressor protein involved in many cellular processes, including cell signaling, apoptosis, and autophagy. In ciliated cells, FLCN localizes to primary cilia and controls mTORC1 signaling in response to flow stress. Here, we show that the ciliary localization of FLCN requires its interaction with kinesin-2, the motor protein for anterograde intraflagellar transport. FLCN binds to kinesin-2 through a loop region in the middle of the protein. Single point mutations within this region of FLCN disrupt its kinesin-2 binding and ciliary entry. The mutants lose the ability to suppress the abnormal mTORC1/2 signaling activities and anchorage-independent growth of FLCN-deficient tumor cells. These observations suggest that ciliary localization of FLCN is essential for its function as a tumor suppressor.

Plasmonic polymers consisting of metallic nanoparticles (NPs) are able to squeeze light into the deep-subwavelength space and transfer along a highly confined nanoscale path in long range. DNA nanotechnology, particularly benefiting from the molecular programmability of DNA origami, has provided otherwise nearly impossible platforms for constructing plasmonic nanoparticle polymers with designer configurations and nanoscale gaps. Here, we design and assemble a DNA origami hashtag tile that is able to polymerize into one-dimensional chains with high rigidity. The DNA origami hashtag chains are used as frames to enable robust, versatile, and precise arrangement of metallic NPs into micrometer-long chiral and magnetic plasmonic polymers, which are capable of efficiently transporting plasmonic angular momentum and magnetic surface plasmonic polaritons at the deep-subwavelength scale. Our work provides a molecular platform for the fabrication of long, straight, and structurally complex nanoparticle polymers with emerging plasmonic properties that are appealing to a variety of fields.

Background. Gestational diabetes mellitus (GDM) is a type of glucose intolerance disorder that first occurs during women’s pregnancy. The main diagnostic method for GDM is based on the midpregnancy oral glucose tolerance test. The rise of metabolomics has expanded the opportunity to better identify early diagnostic biomarkers and explore possible pathogenesis. Methods. We collected blood serum from 34 GDM patients and 34 normal controls for a LC-MS-based metabolomics study. Results. 184 metabolites were increased and 86 metabolites were decreased in the positive ion mode, and 65 metabolites were increased and 71 were decreased in the negative ion mode. Also, it was found that the unsaturated fatty acid metabolism was disordered in GDM. Ten metabolites with the most significant differences were selected for follow-up studies. Since the diagnostic specificity and sensitivity of a single differential metabolite are not definitive, we combined these metabolites to prepare a ROC curve. We found a set of metabolite combination with the highest sensitivity and specificity, which included eicosapentaenoic acid, docosahexaenoic acid, docosapentaenoic acid, arachidonic acid, citric acid, α-ketoglutaric acid, and genistein. The area under the curves (AUC) value of those metabolites was 0.984 between the GDM and control group. Conclusions. Our results provide a direction for the mechanism of GDM research and demonstrate the feasibility of developing a diagnostic test that can distinguish between GDM and normal controls clearly. Our findings were helpful to develop novel biomarkers for precision or personalized diagnosis for GDM. In addition, we provide a critical insight into the pathological and biological mechanisms for GDM.