Syntrophic methanogenesis is an essential link in the global carbon cycle and a key bioprocess for the disposal of organic waste and production of biogas. Recent studies suggest direct interspecies ...electron transfer (DIET) is involved in electron exchange in methanogenesis occurring in paddy soils, anaerobic digesters, and specific co-cultures with Geobacter. In this study, we evaluate the possible involvement of DIET in the syntrophic oxidation of butyrate in the enrichments from two lake sediments (an urban lake and a natural lake). The results showed that the production of CH4 was significantly accelerated in the presence of conductive nanoscale Fe3O4 or carbon nanotubes in the sediment enrichments. Observations made with fluorescence in situ hybridization and scanning electron microscope indicated that microbial aggregates were formed in the enrichments. It appeared that the average cell-to-cell distance in aggregates in nanomaterial-amended enrichments was larger than that in aggregates in the non-amended control. These results suggested that DIET-mediated syntrophic methanogenesis could occur in the lake sediments in the presence of conductive materials. Microbial community analysis of the enrichments revealed that the genera of Syntrophomonas, Sulfurospirillum, Methanosarcina, and Methanoregula were responsible for syntrophic oxidation of butyrate in lake sediment samples. The mechanism for the conductive-material-facilitated DIET in butyrate syntrophy deserves further investigation.
X-ray microcomputed tomography (X-ray μCT) method is proposed to trace steel corrosion and corrosion-induced cracking in cement paste. Experimental results show it can track the time-dependent ...development of steel corrosion and corrosion products, as well as the subsequent initiation and propagation of corrosion-induced cracks. Furthermore, the information of corrosion pits, corrosion products, and corrosion-induced cracks can be clearly obtained from the whole specimen by this novel method. Additionally, SEM/EDS results agree closely with image analyses by X-ray μCT. This method provides a new angle to investigate the reinforcement corrosion process and can help to improve the numerical analysis of corrosion-induced damage in reinforced concrete structures.
•Reinforcement corrosion and corrosion-induced cracking is traced by X-ray μCT method.•The development of corrosion products can be determined as a function of time and space.•Subsequent initiation and propagation of corrosion-induced cracks can be monitored.•The time-dependent corrosion process can be quantitative analyzed by X-ray μCT measurement.
Let f be a Boolean function in n variables. The Möbius transform and its converse of f can describe the transformation behaviors between the truth table of f and the coefficients of the monomials in ...the algebraic normal form representation of f. In this letter, we develop the Möbius transform and its converse into a more generalized form, which also includes the known result given by Reed in 1954. We hope that our new result can be used in the design of decoding schemes for linear codes and the cryptanalysis for symmetric cryptography. We also apply our new result to verify the basic idea of the cube attack in a very simple way, in which the cube attack is a powerful technique on the cryptanalysis for symmetric cryptography.
The Carlin-type gold deposit is best known in Nevada (USA) and SW China. In this paper, we report detailed field geology and mineral geochemical studies of gold-bearing pyrites from Lannigou ...Carlin-type Au deposit, SW China. Geological observations indicate that Lannigou Au deposit is a sediment-hosted gold deposit with quartz veins and controlled by steeply-dipping NW-trending F3, F6 fault and the intersection of F3 fault and NE-striking F2 fault, or secondary faults. As the main host mineral, arsenic pyrite is characterized by core-rim structure. And there is significant zonation in pyrite rim. EPMA data shows that core is characterized by low As, Au, Cu and higher Ni concentration. In contrast, rim has elevated concentration of As, Au and Cu. NanoSIMS mapping reveals the zonation of elements distribution including As, Au and Cu. According the textures and distributions of As and Au, we recognized three main stages of pyrites and late stage sulfides. Stage 1 pyrites were formed prior mineralization process. Stage 2, arsenic pyrites precipitated without Au. Stage 3, main Au precipitation taken place. Line scan of pyrite rims reveal that the peaks of As and Au were coupled with valley of δ34S in stage 3a and the correlations between As and Au are different in stage 3a and 3b. These observations indicate that Au precipitation mainly caused by fluid mixing. S isotope analyzed by NanoSIMS reveals a mixing trend between a magmatic-related fluid with δ34S value about 0‰ and a basin fluid with δ34S value about 18‰.
Display omitted
•The distribution of ore-related elements and δ34S across individual pyrite crystals, from representative Carlin-type gold deposit in SW China, are determined by NanoSIMS.•The complex Au-As relationships revealed by NanoSIMS indicate multiple mechanisms of Au precipitation during mineralization.•The significant variation of δ34S value across individual pyrite grains reveal a mixing process of hydrothermal ore fluids. One of the origin could be trace element enriched fluid with mantle-like δ34S and another is a crustal fluid with elevated δ34S.
Sulfur isotope signatures of Au-bearing pyrite from Lannigou Au deposit, a typical Carlin-type Au deposit in SW China, provide valuable information about the origin of the ore-forming minerals. Analysis by NanoSIMS was used to determine S isotope compositions of Au-bearing pyrite and to map the grain-scale distributions of Au, Cu, As and S in pyrite from the deposit. Based on different textural pattern of pyrites revealed by back-scattered electron (BSE) images, they are divided into three types: Py-1 diagenetic pyrite without core-rim structure, Py-2 pyrite with an Au-free core and a rhythmically-zoned Au-bearing rim, Py-3 Au-bearing pyrite with rhythmic zoning across the entire grain. The element distributions and S isotope compositions of four paragenetic stages are recognized on the basis of textural observation. Py-1 grains and the Au-free homogeneous cores of zoned crystals were formed in Stage 1 while the Au-bearing rims of the zoned crystals with rhythmic zonation of As and Cu, and to a lesser degree Au, were formed in two superimposed stages: stage 2 formed the inner zone that is enriched in As alone; and stage 3 formed the outer zone that is enriched in both Au and As. Other sulfides such as realgar, cinnabar and stibnite are formed in the last stage. The relationship between Au and As distributions in pyrite rim is complicated, changing from coupled to decoupled at the nanoscale. Such complexity is interpreted to reflect fluctuation of fluid composition and temperature with time, which in turn affect the modes of occurrence of As and Au. It is inferred that As mainly occurs in the crystal lattice replacing S whereas Au is mainly present as nanoparticles that were trapped in pyrite during crystal growth. The Au-bearing rims of the zoned pyrite crystals are characterized by highly variable δ34S values from 1.1 to 18.1‰, which exceed the values of the Triassic calcareous host rocks (10–14‰). In contrast, the δ34S values of the Au-free cores of zoned pyrite crystals vary over a narrower interval and are mainly between 6 and 12‰, close to the values of pyrite crystals in the sedimentary country rocks. Our new analyses also reveals that the δ34S values of the Au-bearing fluids generally increase during the formation of the deposit. The observed S isotope variations are consistent with mixing between a magmatic-related fluid with mantle-like δ34S value (∼0‰) and a sedimentary or deep basin brine fluid with elevated δ34S value (>18‰), with an increasing contribution from the latter with time. The notably varied values of δ34S and the disseminations of Au and other trace elements such as As and Cu in pyrite crystals indicate that the process responsible for Au precipitation in this deposit occurred in an open hydrothermal system.
This paper presents work toward the development of self-healing materials that hold promise for permeability healing of concrete or other cementitious composites. To achieve this innovative system, ...Urea-formaldehyde/Epoxy microcapsule was designed and synthesized by an in-situ polymerization method, using epoxy resin E-51 as the curing agent and urea-formaldehyde resin as the shell material. The viability of microcapsule and the influence of microcapsules on mechanical properties of specimens were investigated first. The breakage of microcapsules upon cracking and the crack-healing results were verified by SEM/EDS. Self-healing capacity was evaluated by crack-healing effect and chloride permeability. The experimental results shown that the chloride diffusion coefficient decreased from 8.15 to 6.53 ( × 10−12 m2 s−1) after 28-day healing. The healing efficiency of permeability increased to a maximum level of 19.8%. It was also noticed that several factors such as the amount of microcapsules, particle size, healing age, curing temperature and pre-load level have great influences on the self-healing efficiency.
Breast cancers enduring treatment with chemotherapy may be enriched for cancer stem cells or tumor-initiating cells, which have an enhanced capacity for self-renewal, tumor initiation, and/or ...metastasis. Breast cancer cells that express the type I tyrosine kinaselike orphan receptor ROR1 also may have such features. Here we find that the expression of ROR1 increased in breast cancer cells following treatment with chemotherapy, which also enhanced expression of genes induced by the activation of Rho-GTPases, Hippo-YAP/TAZ, or B lymphoma Mo-MLV insertion region 1 homolog (BMI1). Expression of ROR1 also enhanced the capacity of breast cancer cells to invade Matrigel, form spheroids, engraft in
Rag2
−
/
−
γ
c
−
/
−
mice, or survive treatment with paclitaxel. Treatment of mice bearing breast cancer patient-derived xenografts (PDXs) with the humanized anti-ROR1 monoclonal antibody cirmtuzumab repressed expression of genes associated with breast cancer stemness, reduced activation of Rho-GTPases, Hippo-YAP/TAZ, or BMI1, and impaired the capacity of breast cancer PDXs to metastasize or reengraft
Rag2
−
/
−
γ
c
−
/
−
mice. Finally, treatment of PDX-bearing mice with cirmtuzumab and paclitaxel was more effective than treatment with either alone in eradicating breast cancer PDXs. These results indicate that targeting ROR1 may improve the response to chemotherapy of patients with breast cancer.
This study investigated the particle size‐ and age‐dependent mixing structures of individual particles in clean and polluted air. Aerosols were classified into eight components: sea salt, mineral ...dust, fly ash, metal, soot, sulfates, nitrates, and organic matter (OM). Based on our aerosol classification, a particle that consists of two or more aerosol components can be defined as an internally mixed particle. Otherwise, it is considered to be an externally mixed particle. Within the internally mixed particle class, we identified four heterogeneous mixing structures: core‐shell, dumbbell, OM coating, and dispersed OM, as well as one homogeneous‐like mixing structure. Homogeneous‐like mixing mainly occurred in fine particles (<1 µm), while the frequency of heterogeneously mixed particles increased with particle size. Our study demonstrated that particle mixing structures depend on particle size and location and evolve with time. OM‐coating and core‐shell structures are important indicators for particle aging in air as long as they are distant from specific emission sources. Long‐range transported particles tended to have core‐shell and OM‐coating structures. We found that secondary aerosol components (e.g., sulfates, nitrates, and organics) determined particle mixing structures, because their phases change following particle hydration and dehydration under different relative humidities. Once externally mixed particles are transformed into internally mixed particles, they cannot revert to their former state, except when semivolatile aerosol components are involved. Categorizing mixing structures of individual particles is essential for studying their optical and hygroscopic properties and for tracing the development of their physical or chemical properties over time.
Key Points
Our study systematically identifies mixing structures within internally mixed particles
Particle mixing structures depend on particle size and location and they evolve over time
Secondary aerosol formation mainly determined particle mixing structures in this study
Accumulated unfolded proteins in the endoplasmic reticulum (ER) trigger the unfolded protein response (UPR) to increase ER protein folding capacity. ER proteostasis and UPR signaling need to be ...regulated in a precise and timely manner. Here, we identify phosphorylation of protein disulfide isomerase (PDI), one of the most abundant and critical folding catalysts in the ER, as an early event during ER stress. The secretory pathway kinase Fam20C phosphorylates Ser357 of PDI and responds rapidly to various ER stressors. Phosphorylation of Ser357 induces an open conformation of PDI and turns it from a “foldase” into a “holdase”, which is critical for preventing protein misfolding in the ER. Phosphorylated PDI also binds to the lumenal domain of IRE1α, a major UPR signal transducer, and attenuates excessive IRE1α activity. Importantly, PDI‐S359A knock‐in mice display enhanced IRE1α activation and liver damage under acute ER stress. We conclude that the Fam20C‐PDI axis constitutes a post‐translational response to maintain ER proteostasis and plays a vital role in protecting against ER stress‐induced cell death.
Synopsis
Endoplasmic reticulum (ER) proteostasis and unfolded protein response (UPR) signaling need to be regulated in a precise and timely manner. Here, phosphorylation of protein disulfide isomerase (PDI) by secretory pathway kinase Fam20C turns PDI activity from “foldase” into “holdase”, thereby protecting mouse liver from ER stress‐induced cell death.
Fam20C phosphorylates ER‐associated PDI on Serine 357 rapidly after ER stress.
Ser357 phosphorylation induces a functional switch that transforms PDI from a ‘foldase’ into a ‘holdase’ chaperone.
Phosphorylated PDI safeguards ER proteostasis and attenuates excessive activity of UPR transducer IRE1α.
PDI phosphorylation is critical for preventing liver damage under ER stress in vivo.
Fam20C‐dependent phosphorylation of protein disulfide isomerase (PDI) turns PDI activity from “foldase” into “holdase”, thereby protecting mouse liver from ER stress‐induced cell death.
Passive wireless surface acoustic wave (SAW) resonant sensors are widely used in measuring pressure, temperature, and torque, typically detecting sensing parameters by measuring the echo signal ...frequency of SAW resonators. Therefore, the accuracy of echo signal frequency estimation directly affects the performance index of the sensor. Due to the exponential attenuation trend of the echo signal, the duration is generally approximately 10 μs, with conventional frequency domain analysis methods limited by the sampling frequency and data points. Thus, the resolution of frequency estimation is limited. Here, signal time-domain fitting combined with a genetic algorithm is used to estimate SAW echo signal frequency. To address the problem of slow estimation speed and poor timeliness caused by a conventional genetic algorithm, which needs to simultaneously estimate multiple parameters, such as signal amplitude, phase, frequency, and envelope, the Hilbert transform is proposed to remove the signal envelope and estimate its amplitude, and the fast Fourier transform subsection method is used to analyze the initial phase of the signal. The genetic algorithm is thereby optimized to realize the frequency estimation of SAW echo signals under a single parameter. The developed digital signal processing frequency detection system was monitored in real time to estimate the frequency of an SAW echo signal lasting 10 μs and found to have only 100 sampling points. The proposed method has a frequency estimation error within 3 kHz and a frequency estimation time of less than 1 s, which is eight times faster than the conventional genetic algorithm.
Downregulation of epithelial markers and upregulation of mesenchymal markers are the characteristics of the epithelial to mesenchymal transition (EMT) program, which provides the metastatic advantage ...of breast cancer. However, the mechanism underlying the switch of EMT markers remains poorly understood.
In this study, we used the affinity purification and mass spectrometry coupled approach to identify the interactome of Slug. CoIP, GST-pulldown, ChIP, Re-ChIP, qPCR and Immunoblot were used to investigate the underlying mechanism of Slug-PRMT5-LSD1 complex. The role of PRMT5 and LSD1 in breast cancer progression was evaluated both in vivo and in vitro.
Here we found that the transcription factor Slug associates with PRMT5 and LSD1 in a complex and facilitates the breast cancer invasion in vitro. Mechanistically, PRMT5 and LSD1 work with Slug to exert dual transcriptional activities to inhibit E-cadherin expression by PRMT5-catalyzed H4R3me2s and LSD1-mediated demethylation of H3K4me2 on the E-cadherin (CDH1) promoter, and activate vimentin (VIM) expression via PRMT5-driven H3R2me2s and LSD1-mediated removal of H3K9me2. Importantly, PRMT5 and LSD1 are coordinately expressed in breast cancer patients and pharmacologic perturbation of both PRMT5 and LSD1 shows a synergetic effect on the inhibition of breast tumor growth and metastasis in vivo.
Our study suggests that PRMT5 and LSD1 function as a dual epigenetic modifier to promote Slug induced EMT program, suggesting that the inhibition of PRMT5 and LSD1 presents a potential therapeutic strategy against cancer metastasis.
PDF
