Experimental study on treatment of Fe2+ and Mn2+ in AMD with lignite combined with Pseudomonas aeruginosa immobilized SRB particles

Sulfate-Reducing Bacteria (SRB) are easily inhibited by high concentrations of heavy metals, low pH as well as the need to add carbon source materials, the microbial immobilization technology was adopted, with SRB, Pseudomonas aeruginosa and lignite as the main immobilization substrates, to prepare lignite and Pseudomonas aeruginosa immobilized SRB particles (L-P-SRB) and the removal effect of L-P-SRB on Fe2+, Mn2+ and SO4 2− in acid mine wastewater (AMD) was investigated. Based on the reduction kinetics and adsorption kinetics, the mechanism of AMD treatment by L-P-SRB was revealed by means of scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR), and the mechanism of L-P-SRB treating AMD was revealed. At the same time, the repair effect of low temperature treatment of L-P-SRB on AMD is explored, which provides a certain basis for the treatment of AMD in mining areas under the condition of low temperature. The results show that the removal rates of Fe2+ and Mn2+ by L-P-SRB are 91% and 79% respectively, and the process of adsorption of Fe2+ and Mn2+ conforms to the pseudo-first-order kinetics; the removal rate of SO4 2− reaches 91.28% and 81.94% respectively, and the process of reducing SO4 2− is in accordance with the first-order kinetics. Compared with Fe2+, Mn2+ has a certain inhibitory effect on the activity of L-P-SRB. L-P-SRB can remove Fe2+, Mn2+ and SO4 2− in wastewater at one time, which well solves the problem that lignite can only adsorb heavy metal ions and SRB needs to add carbon source. Low temperature cold storage treatment will not inhibit the activity of L-P-SRB, which provides a basis for one-time preparation and multiple use. According to the detection of SEM and FT-IR, pseudomonas aeruginosa plays a priority role in the treatment of wastewater by L-P-SRB, destroying the structure of lignite, destroying some functional groups, breaking the C—C bond, C=O bond and side chain of cycloalkanes, alkanes and olefins in lignite, producing a large number of small molecule organic substances, increasing the specific surface area of particles, and improving the adsorption capacity of particles. At the same time, lignite provides a carrier and a large number of carbon sources for the reduction of SO4 2− by SRB, which promotes the growth of SRB and improves the treatment effect of AMD

Functional Role of Cyclin-Dependent Kinase 5 in the Regulation of Melanogenesis and Epidermal Structure

The mammalian integumentary system plays important roles in body homeostasis, and dysfunction of melanogenesis or epidermal development may lead to a variety of skin diseases, including melanoma. Skin pigmentation in humans and coat color in fleece-producing animals are regulated by many genes. Among them, microphthalmia-associated transcription factor (MITF) and paired-box 3 (PAX3) are at the top of the cascade and regulate activities of many important melanogenic enzymes. Here, we report for the first time that cyclin-dependent kinase 5 (Cdk5) is an essential regulator of MITF and PAX3. Cdk5 knockdown in mice causes a lightened coat color, a polarized distribution of melanin and hyperproliferation of basal keratinocytes. Reduced expression of Keratin 10 (K10) resulting from Cdk5knockdown may be responsible for an abnormal epidermal structure. In contrast, overexpression of Cdk5 in sheep (Ovis aries) only produces brown patches on a white background, with no other observable abnormalities. Collectively, our findings show that Cdk5 has an important functional role in the regulation of melanin production and transportation and in normal development of the integumentary system

Binding of MBNL1 to CUG repeats slows 5'-to-3' RNA decay by XRN2 in a cell culture model of type I myotonic dystrophy

2017 Fall.Includes bibliographical references.Type I myotonic dystrophy (DM1) is a multi-systemic inherited disease caused by expanded CTG repeats within the 3' UTR of the dystrophia myotonica protein kinase (DMPK) gene. The encoded CUG repeat-containing mRNAs are toxic to the cell and accumulate in nuclear foci, where they sequester cellular RNA-binding proteins such as the splicing factor Muscleblind-1 (MBNL1). This leads to widespread changes in gene expression. Currently, there is no treatment or cure for this disease. Targeting CUG repeat-containing mRNAs for degradation is a promising therapeutic avenue for myotonic dystrophy, but we know little about how and where these mutant mRNAs are naturally decayed. We established an inducible C2C12 mouse myoblast model to study decay of reporter mRNAs containing the DMPK 3' UTR with 0 (CUG0) or ~700 (CUG700) CUG repeats and showed that the CUG700 cell line exhibits characteristic accumulation of repeat-containing mRNA in nuclear foci. We utilized qRT-PCR and northern blotting to assess the pathway and rate of decay of these reporter mRNAs following depletion of mRNA decay factors by RNA interference. We have identified four factors that influence decay of the repeat-containing mRNA – the predominantly nuclear 5' 3' exonuclease XRN2, the nuclear exosome containing RRP6, the RNA-binding protein MBNL1, and the nonsense-mediated decay factor, UPF1. We have discovered that the 5' end of the repeat-containing transcript is primarily degraded in the nucleus by XRN2, while the 3' end is decayed by the nuclear exosome. Interestingly, we have shown for the first time that the ribonucleoprotein complex formed by the CUG repeats and MBNL1 proteins represents a barrier for XRN2-mediated decay. We suggest that this limitation in XRN2-mediated decay and the resulting delay in degradation of the repeats and 3' region may play a role in DM1 pathogenesis. Additionally, our results support previous studies suggesting that UPF1 plays a role in initiating the degradation of mutant DMPK transcripts. This work uncovers a new role for MBNL1 in DM1 and other CUG-repeat expansion diseases and identifies the nuclear enzymes involved in decay of the mutant DMPK mRNA. Our model has numerous applications for further dissecting the pathways and factors involved in removing toxic CUG-repeat mRNAs, as well as in identifying and optimizing therapeutics that enhance their turnover

Hybrid Structure Multichannel All-Fiber Current Sensor

We have experimentally developed a hybrid-structure multi-channel all-fiber current sensor with ordinary silica fiber using fiber loop architecture. According to the rationale of time division multiplexing, the sensor combines parallel and serial structures. The purpose of the hybrid-structure multi-channel all-fiber current sensor is to get more information from the different measured points simultaneously. In addition, the hybrid-structure fiber current sensor exhibited a good linear response for each channel. A three-channel experiment was performed in the study and showed that the system could detect different current positions. Each channel could individually detect the current and needed a separate calibration system. Furthermore, the three channels will not affect each other

Effect of early dietary energy restriction and phosphorus level on subsequent growth performance, intestinal phosphate transport, and AMPK activity in young broilers.

We aimed to determine the effect of low dietary energy on intestinal phosphate transport and the possible underlying mechanism to explain the long-term effects of early dietary energy restriction and non-phytate phosphorus (NPP). A 2 × 3 factorial experiment, consisting of 2 energy levels and 3 NPP levels, was conducted. Broiler growth performance, intestinal morphology in 0-21 days and 22-35 days, type IIb sodium-phosphate co-transporter (NaPi-IIb) mRNA expression, adenylate purine concentrations in the duodenum, and phosphorylated adenosine monophosphate-activated protein kinase (AMPK-α) activity in 0-21 days were determined. The following results were obtained. (1) Low dietary energy (LE) induced a high feed conversion ratio (FCR) and significantly decreased body weight gain in young broilers, but LE induced significantly higher compensatory growth in low NPP (LP) groups than in the high or medium NPP groups (HP and MP). (2) LE decreased the villus height (VH) in the intestine, and LE-HP resulted in the lowest crypt depth (CD) and the highest VH:CD ratio in the initial phase. However, in the later period, the LE-LP group showed an increased VH:CD ratio and decreased CD in the intestine. (3) LE increased ATP synthesis and decreased AMP:ATP ratio in the duodenal mucosa of chickens in 0-21 days, and LP diet increased ATP synthesis and adenylate energy charges but decreased AMP production and AMP:ATP ratio. (4) LE led to weaker AMPK phosphorylation, higher mTOR phosphorylation, and higher NaPi-IIb mRNA expression. Thus, LE and LP in the early growth phase had significant compensatory and interactive effect on later growth and intestinal development in broilers. The effect might be relevant to energy status that LE leads to weaker AMPK phosphorylation, causing a lower inhibitory action toward mTOR phosphorylation. This series of events stimulates NaPi-IIb mRNA expression. Our findings provide a theoretical basis and a new perspective on intestinal phosphate transport regulation, with potential applications in broiler production

A Method for Determining Intrinsic Mode Function Number in Variational Mode Decomposition and Its Application to Bearing Vibration Signal Processing

Variational mode decomposition (VMD) method has been widely used in the field of signal processing with significant advantages over other decomposition methods in eliminating modal aliasing and noise robustness. The number (usually denoted by K) of intrinsic mode function (IMF) has a great influence on decomposition results. When dealing with signals including complex components, it is usually impossible for the existing methods to obtain correct results and also effective methods for determining K value are lacking. A method called center frequency statistical analysis (CFSA) is proposed in this paper to determine K value. CFSA method can obtain K value accurately based on center frequency histogram. To shed further light on its performance, we analyze the behavior of CFSA method with simulation signal in the presence of variable components amplitude, components frequency, and components number as well as noise amplitude. The normal and fault vibration signals obtained from a bearing experimental setup are used to verify the method. Compared with maximum center frequency observation (MCFO), correlation coefficient (CC), and normalized mutual information (NMI) methods, CFSA is more robust and accurate, and the center frequencies results are consistent with the main frequencies in FFT spectrum

Hard milling of carburized and waterjet peened 18CrNiMo7-6 steel

Post-mixed waterjet peening is an effective treatment method for compressive residual stress field. After peening, the surface quality of the parts is low, and the hardness is usually higher than 60HRC. A fine manufacturing process should be carried out to obtain a satisfactory surface roughness without side effect on existing residual stress. In this article, the 18CrNiMo7-6 steel after carburization was subjected to post-mixed waterjet peening, the surface hardness was 66HRC and the maximum compressive residual stress was about 1242.86 MPa. Hard milling with CBN inserts were used to remove the rough surface layer of 18CrNiMo7-6. The hardness after milling has changed about 1-2HRC lower than that before cutting. When the cutting speed v c is 753.6 m/min, the feed speed v f is 0.04 mm/min and the cutting depth a p is 0.02 mm, compared to the original Ra 1.204 μm, the best surface roughness can reach Ra 0.0823 μm. When a p exceeds the maximum residual stress location point of 60 μm, the cutting effect will significantly change the residual stress. Considering the hardness, surface roughness and residual stress, the recommended milling parameters v f and a p should use the lower values, the range of v c should be 500–700 m/min and sufficient coolant is required during the cutting process

A Loop All-Fiber Current Sensor Based on Single-Polarization Single-Mode Couplers

Low current sensitivity and insufficient system stability are two key problems in all-fiber current sensor (AFCS) studies. In order to solve the two problems, a novel AFCS combining single-polarization single-mode (SPSM) couplers and a loop structure is presented in this paper with a design that incorporates the advantages of both SPSM couplers and a loop structure. SPSM couplers are shown to simplify the AFCS system and reduce the risk of interference, and the loop structure can enhance the current sensitivity. Both theory and experiment prove that the new AFCS can simultaneously overcome two prevalent obstacles of low current sensitivity and low stability

Characterization of preclinical Alzheimer’s disease model: spontaneous type 2 diabetic cynomolgus monkeys with systemic pro-inflammation, positive biomarkers and developing AD-like pathology

Abstract Background The key to the prevention and treatment of Alzheimer’s disease (AD) is to be able to predict and diagnose AD at the preclinical or early stage, but the lack of a preclinical model of AD is the critical factor that causes this problem to remain unresolved. Methods We assessed 18 monkeys in vivo evaluation of pro-inflammatory cytokines and AD pathological biomarkers (n = 9 / type 2 diabetic mellitus (T2DM) group, age 20, fasting plasma glucose (FPG) ≥ 100 mg/dL, and n = 9 / negative control (NC) group, age 17, FPG < 100 mg/dL). Levels of pro-inflammatory cytokines and AD pathological biomarkers was measured by ELISA and Simoa Technology, respectively. 9 monkeys evaluated ex vivo for AD-like pathology (n = 6 / T2DM group, age 22.17, FPG ≥ 126 mg/dL, and n = 3 / NC group, age 14.67, FPG < 100 mg/dL). To evaluate the pathological features of AD in the brains of T2DM monkeys, we assessed the levels of Aβ, phospho-tau, and neuroinflammation using immunohistochemistry, which further confirmed the deposition of Aβ plaques by Bielschowsky’s silver, Congo red, and Thioflavin S staining. Synaptic damage and neurodegeneration were assessed by immunofluorescence. Results We found not only increased levels of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α) in peripheral blood (PB) and brain of T2DM monkeys but also changes in PB of AD pathological biomarkers such as decreased β-amyloid (Aβ) 42 and Aβ40 levels. Most notably, we observed AD-like pathological features in the brain of T2DM monkeys, including Aβ plaque deposition, p-tau from neuropil thread to pre-neurofibrillary tangles (NFTs), and even the appearance of extracellular NFT. Microglia were activated from a resting state to an amoeboid. Astrocytes showed marked hypertrophy and an increased number of cell bodies and protrusions. Finally, we observed impairment of the postsynaptic membrane but no neurodegeneration or neuronal death. Conclusions Overall, T2DM monkeys showed elevated levels of peripheral and intracerebral inflammation, positive AD biomarkers in body fluids, and developing AD-like pathology in the brain, including Aβ and tau pathology, glial cell activation, and partial synaptic damage, but no neuronal degeneration or death as compared to the healthy normal group. Hereby, we consider the T2DM monkeys with elevation of the peripheral pro-inflammatory factors and positive AD biomarkers can be potentially regarded as a preclinical AD model