Urban tailwater typically has a low carbon-to-nitrogen ratio and adding external carbon sources can effectively improve the denitrification performance of wastewater. However, it is difficult to ...determine the dosage of additional carbon sources, leading to insufficient or excessive addition. Therefore, it is necessary to prepare solid slow-release carbon source (SRC) materials to solve the difficulty in determining the dosage of carbon sources. This study selected two SRCs of slow-release carbon source 1 (SRC1) and slow-release carbon source 2 (SRC2), with good slow-release performance after static carbon release and batch experiments. The composition of SRC1 was: hydroxypropyl methylcellulose/disodium fumarate/polyhydroxy alkanoate (HPMC/DF/PHA) at a ratio of 3:2:4, with an Fe
O
mass fraction of 3%. The composition of SRC2 was: HPMC/DF/PHA with a ratio of 1:1:1 and an Fe
O
mass fraction of 3%. The fitted equations of carbon release curves of SRC1 and SRC2 were
= 61.91 + 7190.24e
and
= 47.92 + 8770.42e
, respectively. The surfaces of SRC1 and SRC2 had a loose and porous morphological structure, which could increase the specific surface area of materials and be more conducive to the adhesion and metabolism of microorganisms. The experimental nitrogen removal by denitrification with SRCs showed that when the initial total nitrogen concentration was 40.00 mg/L, the nitrate nitrogen (NO
-N) concentrations of the SRC1 and SRC2 groups on the 10th day were 2.57 and 2.66 mg/L, respectively. On the 20th day, the NO
-N concentrations of the SRC1 and SRC2 groups were 1.67 and 2.16 mg/L, respectively, corresponding to removal efficiencies of 95.83% and 94.60%, respectively. The experimental results indicated that SRCs had a good nitrogen removal effect. Developing these kinds of materials can provide a feasible way to overcome the difficulty in determining the dosage of carbon sources in the process of heterotrophic denitrification.
A theoretical model has been proposed to predict the horizontal dimensional accuracy of selective laser melting (SLM) in this paper. It is found that the horizontal dimensional deviation of SLM ...consists of two parts. The first part is related to the mode of track filling and the track width. The effect of heat accumulation on track width is also taken into account in this model. The second part is the solidification shrinkage which is dominated by the temperature history of the tracks of a layer when the material and dimension size are fixed. Then, the SLMed Ti6Al4V parts fabricated to verify this theoretical model has been performed in this paper too. The results show that the predicted and experimental results has a good correspondence. At last, less than 20μm dimension deviation of SLMed thin-wall samples was achieved by pre-compensation using this theoretical model.
Display omitted
•A theoretical model has been proposed to predict and optimize the horizontal dimensional accuracy.•The dimension of SLMed Ti6Al4V thin-wall samples were measured to verify this model.•Two parts of the horizontal dimensional accuracy were calculated.
Mesenchymal stem cells (MSCs) are the most promising seed cells for cell therapy. Comparing the biological and transcriptome gene characteristics of MSCs from different sources provides an important ...basis for the screening of clinically used cells. The main purpose of this experiment was to establish methods for the isolation and culture of MSCs from five different canine sources, including adipose tissue, bone marrow, umbilical cord, amniotic membrane, and placenta, and compare biological and transcriptome characteristics of MSCs, in order to provide a basis for the clinical application of canine MSCs. MSCs were isolated from Chinese pastoral dogs, and the following experiments were performed: (1) the third, sixth, and ninth generations of cells were counted, respectively, and a growth curve was plotted to calculate the MSC population doubling time; (2) the expression of CD34 and CD44 surface markers was studied by immunofluorescence; (3) the third generation of cells were used for osteogenetic and adipogenic differentiation experiments; and (4) MSC transcriptome profiles were performed using RNA sequencing. All of the five types of MSCs showed fibroblast-like adherent growth. The cell surface expressed CD44 instead of CD34; the third-generation MSCs had the highest proliferative activity. The average population doubling time of adipose mesenchymal stem cells (AD-MSCs), placenta mesenchymal stem cells (P-MSCs), bone marrow mesenchymal stem cells (BM-MSCs), umbilical cord mesenchymal stem cells (UC-MSCs), and amniotic mesenchymal stem cells (AM-MSCs) were 15.8 h, 21.2 h, 26.2 h, 35 h, and 41.9 h, respectively. All five types of MSCs could be induced to differentiate into adipocytes and osteoblasts in vitro, with lipid droplets appearing after 8 days and bone formation occurring 5 days after AD-MSC induction. However, the multilineage differentiation for the remaining of MSCs was longer compared to that of the AD-MSCs. The MSC transcriptome profiles showed that AD-MSC and BM-MSCs had the highest homology, while P-MSCs were significantly different compared to the other four types of MSCs. All the isolated MSCs had the main biological characteristics of MSCs. AD-MSCs had the shortest time for proliferation, adipogenesis, and osteogenic differentiation.
Timber, the most prevalent organic material on this planet, is the result of a secondary xylem emerging from vascular cambium. Yet, the intricate processes governing its seasonal generation are ...largely a mystery. To better understand the cyclic growth of vascular tissues in elm, we undertook an extensive study examining the anatomy, physiology, and genetic expressions in Ulmus pumila. We chose three robust 15-year-old elm trees for our study. The cultivars used in this study were collected from the Inner Mongolia Autonomous Region in China and nurtured in the tree farm of Shandong Normal University. Monthly samples of 2-year-old elm branches were taken from the tree from February to September. Marked seasonal shifts in elm branch vascular tissues were observed by phenotypic observation: In February, the cambium of the branch emerged from dormancy, spurring growth. By May, elms began generating secondary xylem, or latewood, recognized by its tiny pores and dense cell structure. From June to August, there was a marked increase in the thickness of the secondary xylem. Transcriptome sequencing provides a potential molecular mechanism for the thickening of elm branches and their response to stress. In February, the tree enhanced its genetic responses to cold and drought stress. The amplified expression of CDKB, CYCB, WOX4, and ARF5 in the months of February and March reinforced their essential role in the development of the vascular cambium in elm. Starting in May, the elm deployed carbohydrates as a carbon resource to synthesize the abundant cellulose and lignin necessary for the formation of the secondary wall. Major genes participating in cellulose (SUC and CESA homologs), xylan (UGD, UXS, IRX9, IRX10, and IRX14), and lignin (PAL, C4H, 4CL, HCT, C3H, COMT, and CAD) biosynthetic pathways for secondary wall formation were up-regulated by May or/and June. In conclusion, our findings provided a foundation for an in-depth exploration of the molecular processes dictating the seasonal growth of elm timber.
The limitations of traditional von Neumann architectures and digital computing are the bottlenecks for high-speed signal processing capabilities, not to mention the explosion of information growth. ...To tackle this challenge, this paper proposes an artificial neural network (ANN) equalizer based on the memristor for high-speed channel transmission at 112Gbps with 4-level pulse amplitude modulation (PAM4). To implement the PAM4 signal decision circuit based on the softmax algorithm, a comparator is used to make binary decisions for each output, and the only high-level output is further selected for the decision-making. The simulations on the PSPICE platform reveal that the number of input taps and the location of the main tap have the greatest impact on bit error rate (BER) performance. With optimal parameters, the circuit can achieve an impressive BER performance as low as 3.45E-6. To the best of our knowledge, this is the first implementation of channel equalization using memristive circuits, providing a valuable reference for analog circuit implementations of neural network equalizers.
The equalization plays a pivotal role in modern high-speed optical wire-line transmission. Taking advantage of the digital signal processing architecture, the deep neural network (DNN) is introduced ...to realize the feedback-free signaling, which has no processing speed ceiling due to the timing constraint on the feedback path. To save the hardware resource of a DNN equalizer, a parallel decision DNN is proposed in this paper. By replacing the soft-max decision layer with hard decision layer, multi-symbol can be processed within one neural network. The neuron increment during parallelization is only linear with the layer count, rather than the neuron count in the case of duplication. The simulation results show that the optimized new architecture has competitive performance with the traditional 2-tap decision feedback equalizer architecture with 15-tap feed forward equalizer at a 28GBd, or even 56GBd, four-level pulse amplitude modulation signal with 30dB loss. And the training convergency of the proposed equalizer is much faster than its traditional counterpart. An adaptive mechanism of the network parameter based on forward error correction is also studied.
Cohort evidence that links long-term exposures to air pollution and mortality comes largely from the United States and European countries. We investigated the relationship between long-term exposures ...to particulate matter <10μm in diameter (PM10), nitrogen dioxide (NO2), and sulfur dioxide (SO2) and mortality of lung cancer in Northern China. A cohort of 39,054 participants were followed during 1998–2009. Annual average concentrations for PM10, NO2, and SO2 were determined based on data collected from central monitoring stations. Lung cancer deaths (n=140) were obtained from death certificates, and hazard ratios (HRs) were estimated using Cox proportional hazards models, adjusting for age, gender, BMI, education, marital status, smoking status, passive smoking, occupation, alcohol consumption, etc. Each 10mg/m3 increase in PM10 concentrations was associated with a 3.4%–6.0% increase in lung cancer mortality in the time-varying exposure model and a 4.0%–13.6% increase in the baseline exposure model. In multi-pollutant models, the magnitude of associations was attenuated, most strongly for PM10. The association was different in men and women, also varying across age categories and different smoking status. Substantial differences exist in the risk estimates for participants based on assignment method for air pollution exposure.
Display omitted
•The relationship between exposure to air pollution and lung cancer is proposed.•Levels of PM10 and SO2 were associated with lung cancer mortality independently.•The association was different in men and women, and varied across smoking status.
The nasal mucociliary clearance system, which comprises epithelial cilia and mucus from goblet cells, is an important intrinsic defense mechanism of the upper respiratory tract. Intranasal drugs and ...additives can have a detrimental effect on ciliary activity and mucociliary clearance, and thus impact the integrity of nasal defense mechanisms. This article discusses the current literature on the effects of different classes of intranasal drugs including intranasal corticosteroids, antihistamines, decongestants, antimicrobials and antivirals, as well as various drug excipients and nasal irrigation solutions on human nasal mucociliary clearance and ciliary beat frequency. Available data indicate that some intranasal formulations tend to hamper nasal ciliary function and mucociliary clearance. Therefore, it is of great importance to assess the effects of intranasal drugs and additives on mucociliary function before they are recommended as therapy for different nasal conditions.
Early weaning commonly results in gastrointestinal disorders, inflammation and diarrhea in infants and young animals. Resveratrol, a plant phenol, affords protection against inflammation and cancer. ...A porcine model was used to investigate the effects of maternal dietary resveratrol on diarrhea, intestinal inflammation and the intestinal morphology in offspring during weaning. The results showed that maternal dietary resveratrol alleviated weaning-associated intestinal inflammation and diarrhea and improved the intestinal morphology in offspring. In weaning piglets, maternal dietary resveratrol increased the proportion of butyrate-producing bacteria, such as Flavonifractor, Odoribacter and Oscillibacter, as determined by 16S rRNA sequencing. RNA-seq analysis identified 189 and 139 differentially expressed genes (DEGs) in weaning and post-weaning piglets, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that DEGs were enriched for the T cell receptor, primary immunodeficiency, mitogen-activated protein kinase (MAPK) and Ras signaling pathways in weaning piglets and for the cytokine-cytokine receptor interaction pathway and metabolism-related pathways in post-weaning piglets.
The use of simple building blocks to produce hierarchical and porous structured materials is highly desired. Rings are simple colloidal particles but unique for their internal cavities. Here we ...report the self‐assembly (SA) of colloidal rings with tunable asymmetry mediated by a depletion force and demonstrate that a variety of porous colloidal superstructures from microtubes, flexible chains, (plastic) crystals to highly open liquid crystals (LCs) can be formed along the predesigned SA paths. In particular, the SA is staged in binary or ternary systems. Large rings first form complex ring‐in‐ring and ring‐in‐ring‐in‐ring assemblies by capturing smaller rings, which, as new building blocks, can further form multi‐walled microtubes and open columnar LCs. Moreover, a plastic columnar LC with alternating intracolumnar stacking is found from asymmetrical rings. The SA with colloidal rings opens a new avenue to construct hierarchical and porous ordered metamaterials.
An ideal colloidal ring model system for self‐assembly (SA) is synthesized and its SA is studied. A variety of porous colloidal superstructures from microtubes to highly open liquid crystals is achieved. Staged SA results in complex ring‐in‐ring and ring‐in‐ring‐in‐ring assemblies, which, as new building blocks, further form multi‐walled microtubes and open columnar LCs. A plastic columnar LC with alternating intracolumnar stacking is found.
PDF
