Determining the risk posed by PFAS leaching from soil to groundwater requires quantification of the magnitude and temporal/spatial variability of PFAS mass discharge from the vadose zone, which is ...governed in part by the concentrations of PFAS in soil porewater. Porewater concentrations are impacted and mediated by the properties of the PFAS and soil, multiple transport and fate processes, and site conditions. The objective of this research was to delineate the relationship between soil porewater concentrations and soil concentrations, based on a comprehensive model of PFAS mass distribution within a soil sample volume. Measured parameters representing solid-phase sorption and air-water interfacial adsorption are used to illustrate the impact of soil and PFAS properties on the distribution of representative PFAS between soil and soil porewater. Literature data reported for soil and soil porewater concentrations of several PFAS obtained from outdoor lysimeter experiments are used to test the distribution model. Soil-to-porewater concentration ratios predicted with the model compared very well to the measured concentration ratios. The nondimensional distribution coefficient that describes the distribution of PFAS mass amongst all domains within a soil sample was observed to be a function of PFAS molecular size. Numerical simulations conducted for a model fire-training source area were used to illustrate the ranges in magnitude of soil versus porewater concentrations for representative field conditions. The results of the measured and simulated data sets demonstrated the importance of air-water interfacial adsorption for the distribution of the longer-chain PFAS within soil samples. PFAS soil porewater concentrations are anticipated to range from ng/L to mg/L depending upon soil concentrations, which in turn depend upon the nature of the site.
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•A comprehensive distribution model is developed for PFAS porewater concentration (Cp).•The ratio between soil concentration (Ct) and Cp is a function of soil & PFAS properties.•The Ct/Cp may change during long-term leaching due to nonlinear adsorption processes.•The Ct/Cp changes during infiltration events due to changes in air-water interfacial area.•Air-water interfacial adsorption has a significant impact on Ct/Cp behavior.
Single-cell RNA sequencing has been widely adopted to estimate the cellular composition of heterogeneous tissues and obtain transcriptional profiles of individual cells. Multiple approaches for ...optimal sample dissociation and storage of single cells have been proposed as have single-nuclei profiling methods. What has been lacking is a systematic comparison of their relative biases and benefits.
Here, we compare gene expression and cellular composition of single-cell suspensions prepared from adult mouse kidney using two tissue dissociation protocols. For each sample, we also compare fresh cells to cryopreserved and methanol-fixed cells. Lastly, we compare this single-cell data to that generated using three single-nucleus RNA sequencing workflows. Our data confirms prior reports that digestion on ice avoids the stress response observed with 37 °C dissociation. It also reveals cell types more abundant either in the cold or warm dissociations that may represent populations that require gentler or harsher conditions to be released intact. For cell storage, cryopreservation of dissociated cells results in a major loss of epithelial cell types; in contrast, methanol fixation maintains the cellular composition but suffers from ambient RNA leakage. Finally, cell type composition differences are observed between single-cell and single-nucleus RNA sequencing libraries. In particular, we note an underrepresentation of T, B, and NK lymphocytes in the single-nucleus libraries.
Systematic comparison of recovered cell types and their transcriptional profiles across the workflows has highlighted protocol-specific biases and thus enables researchers starting single-cell experiments to make an informed choice.
Background
Semenogelin 1 (SEMG1) is an important secretory protein in spermatozoa involved in the formation of a gel matrix encasing ejaculated spermatozoa. Previous studies show that the SEMG1 gene ...is highly expressed in spermatozoa from patients with asthenozoospermia (AZS); however, the underlying molecular mechanisms are not yet clear.
Objectives
To study the molecular mechanism of high expression of SEMG1 gene and its potential roles in AZS.
Materials and Methods
Western blot and real‐time PCR were used to detect the expression levels of SEMG1 protein and mRNA in the ejaculated spermatozoa from normozoospermic males and AZS patients. Bioinformatics analysis was used to predict miRNAs targeting for SEMG1 3′‐untranslated region detection of the expression levels of all the candidate miRNAs in ejaculatory spermatozoa in AZS patients or normozoospermic volunteers. Luciferase reporter assays were performed to confirm it can directly bind to SEMG1. Correlation of miR‐525‐3p and SEMG1 mRNA expression with clinical sperm parameters were also analyzed. Finally, we conducted a follow‐up study of reproductive history about all the subjects.
Results
SEMG1 mRNA and protein level were significantly higher in AZS patients compared to that in normozoospermic volunteers (p < 0.001). Subsequently, microRNA‐525‐3p (miR‐525‐3p) which was predicted as a candidate regulator of SEMG1 was found lower expressed in ejaculatory spermatozoa in AZS patients (p = 0.0074). Luciferase experiment revealed that microRNA‐525‐3p could directly target SEMG1 3′‐untranslated region and suppress its expression. Importantly, our retrospective follow‐up study showed that both low miR‐525‐3p expression and high SEMG1 expression level was significantly associated with low progressive sperm motility, abnormal sperm morphology, and infertility.
Discussion and Conclusion
The elevated expression of SEMG1 and reduced expression of miR‐525‐3p are associated with AZS and male infertility. Our study provides a potential therapeutic target for the treatment of male infertility or for male contraception.
Abstract The aim of this study was to identify the risk factors for free flap failure after head and neck reconstructive surgery. The data of 881 consecutive patients who underwent free flap surgery ...at the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, between January 2013 and November 2016, were reviewed retrospectively. All surgeries were performed by a single head and neck surgical team. Patient demographic and surgical data that may have an influence on free flap outcomes were recorded. The χ2 test and multivariate logistic regression analysis were used to identify relevant risk factors. In total, 881 free tissue transfer surgeries were included in this study. Free flap failure occurred in 26 of 881 flaps (2.9%). A history of irradiation (odds ratio 0.205, 95% confidence interval 0.07–0.56; P = 0.002) was a statistically significant risk factor for free flap failure. Age, diabetes mellitus, history of previous neck surgery to the anastomosis side, donor site, choice of recipient vein, use of a coupler device, and postoperative anticoagulation were not associated with free flap outcomes. Thus, it is concluded that when performing head and neck reconstructive surgery, special attention should be paid to patients who have previously undergone irradiation.
Cyanide and copper often co-exist in process water with complicated speciation. The deposition of copper on pyrite from cyanide bearing solutions is unknown and is the objective of this study. The ...electrochemical behaviour of pyrite in a solution with CN/Cu mole ratio of 3/1 has been investigated in different solution pH values. It was found that, at pH 7, cuprous cyanide can be oxidized to Cu(
ii
) oxide/hydroxide which deposit on the pyrite surface and transform to Cu(
i
)-sulfide during the subsequent cathodic sweeping. However, this anodic deposition process is inhibited either at pH 10 due to the dissolution of solid Cu(
ii
)/Cu(
i
)-species by Cu(CN)
3
2−
, or at pH 5 due to the high solubility of Cu(
ii
) oxide/hydroxide. On the other hand, Cu(CN)
2
−
can be deposited onto pyrite, forming a Cu(
i
)-sulfide layer at more reducing potentials. The understanding of the electrodeposition mechanisms provides opportunities for the recovery of copper from cyanide-bearing waste water, as well as the separation of pyrite from other raw materials by altering its surface properties.
Copper anodically deposits on pyrite from cyanide bearing solution at neutral pH, and cathodically deposits at mildly acidic pH.
Ultra-translucent zirconias are drawing immense attention due to their fascinating esthetic appearance. However, the high translucency came at the expense of diminishing strength along with the ...reduced ability of transformation toughening due to the increased cubic zirconia content. We aim to address these issues by infiltrating glass on the surface of an ultra-translucent zirconia (5Y-PSZ). Glasses of different shades can be used and the resulting graded glass/zirconia layer is expected to improve the material’s flexural strength without compromising its esthetics. We also aim to elucidate how clinically relevant surface treatments—namely, air abrasion, glazing, or polishing—affect the fracture resistance of these zirconias with a high cubic content. All surface treatments were performed on bar-shaped (2 × 3 × 25 mm3) and plate-shaped (12 × 12 × 1 mm3) specimens, which were then subjected to a 4-point bending test and translucency measurements, respectively. 5Y-PSZ proved to be significantly more translucent than 3Y-TZP but also much weaker. Our hypothesis was accepted, as the strength of the glass-infiltrated ultra-translucent 5Y-PSZ (582 ± 20 MPa) is over 70% higher than its uninfiltrated counterpart (324 ± 57 MPa). Its strength is also over 25% higher than the highly polished 5Y-PSZ (467 ± 38 MPa). In addition, the translucency of 5Y-PSZ (translucency parameter TP = 34, contrast ratio CR = 0.31) is not affected by glass infiltration (TP = 34, CR = 0.32) when the residual surface glass is removed by gentle polishing using 6- and then 3-µm diamond grits. Finally, both air abrasion and the presence of a glaze layer on the tensile surface decreased flexural strength significantly, being 274 ± 55 and 211 ± 21 MPa, respectively. With a combined high strength and translucency, the newly developed glass-infiltrated 5Y-PSZ may be considered a suitable material for next-generation, damage-resistant, and esthetic dental restorations.
•Cultivation of microalgae Chlorella sp. with livestock waste compost was investigated.•Biomass productivity ranged from 184.22 to 288.84mgL−1day−1.•As the initial nutrient concentration decreased, ...the lipid content increased.•Lipid productivity ranged from 84.76 to 104.89mgL−1day−1.•The livestock waste compost medium with 2000mgL−1 COD was optimal for algal growth.
Cultivation of microalgae Chlorella sp. with livestock waste compost as an alternative nutrient source was investigated in this present study. Five culture media with different nutrient concentrations were prepared. The characteristics of algal growth and lipid production were examined. The results showed that the specific growth rate together with biomass and lipid productivities was different among all the cultures. As the initial nutrient concentration decreased, the lipid content of Chlorella sp. increased. The variations in lipid productivity of Chlorella sp. among all the cultures were mainly due to the deviations in biomass productivity. The livestock waste compost medium with 2000mgL−1COD provided an optimal nutrient concentration for Chlorella sp. cultivation, where the highest productivities of biomass (288.84mgL−1day−1) and lipid (104.89mgL−1day−1) were presented.
Ultrasonic vibration is widely utilized in manufacturing processes mainly because acoustic field could significantly affect the metal plasticity leading to stress reduction. However, viewpoints on ...the influence mechanism have not reached a consensus yet. In this paper, an ultrasonic vibration assisted uniaxial tension experiment with copper foils is carried out using a specially-developed device. The results show that the extent of stress reduction increases with the increase of the vibration amplitude. Acoustic softening and stress superposition are both considered in a developed model to describe the stress reduction due to ultrasonic excitation during metal forming process. Considering that ultrasonic vibration provides the energy for dislocation sliding, acoustic softening is analyzed based on crystal plasticity theory considering ultrasonic intensity. Stress superposition, mostly induced by the additional periodic strain, is included by taking account of its proportional relationship with vibration amplitude. The calculation results from the numerical model show a good agreement with those from the experiment. These findings provide an instructive understanding of mechanism of stress reduction in ultrasonic vibration assisted metal deformation and are especially helpful for pro-actively designing ultrasonic vibration assisted metal forming processes.
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•Remarkable stress reduction is observed during the ultrasonic assisted tension.•A hybrid model is developed considering both acoustic softening and stress superposition to describe the stress reduction.•These findings show that the stress reduction induced by acoustic softening is mainly determined by acoustic energy density.•Stress reduction induced by stress superposition is explained by power law expression based on vibration amplitudes.
The effects of land use change on soil carbon stocks are of concern in the context of international policy agendas on greenhouse gas emissions mitigation. This paper reviews the literature for the ...influence of land use changes on soil C stocks and reports the results of a meta analysis of these data from 74 publications. The meta analysis indicates that soil C stocks decline after land use changes from pasture to plantation (−10%), native forest to plantation (−13%), native forest to crop (−42%), and pasture to crop (−59%). Soil C stocks increase after land use changes from native forest to pasture (+ 8%), crop to pasture (+ 19%), crop to plantation (+ 18%), and crop to secondary forest (+ 53%). Wherever one of the land use changes decreased soil C, the reverse process usually increased soil carbon and vice versa. As the quantity of available data is not large and the methodologies used are diverse, the conclusions drawn must be regarded as working hypotheses from which to design future targeted investigations that broaden the database. Within some land use changes there were, however, sufficient examples to explore the role of other factors contributing to the above conclusions. One outcome of the meta analysis, especially worthy of further investigation in the context of carbon sink strategies for greenhouse gas mitigation, is that broadleaf tree plantations placed onto prior native forest or pastures did not affect soil C stocks whereas pine plantations reduced soil C stocks by 12–15%.
The prevalence of diabetes in China is among the highest in the world. For this reason, findings from the 2016 Global Burden of Disease (GBD) study were used to calculate the burden of hyperglycaemia ...and diabetes in China.
Following the general analytical strategy used in GBD 2016, diabetes prevalence and mortality were analyzed by age and gender. Trends in disability-adjusted life years (DALYs) due to diabetes were assessed in 33 province-level administrative units from 1990 to 2016, and similar data were provided for chronic kidney disease (CKD) related to diabetes and, as an overall summarizing measure, for hyperglycaemia expressed as high fasting plasma glucose (HFPG).
From 1990 to 2016, all-age prevalence of diabetes rose from 3.7% to 6.6%, and all-age diabetes and diabetes-related CKD mortality rates increased by 63.5% and 33.3%, respectively, with both rates increasing more rapidly in diabetes patients aged 15–49 years than in any other age groups. In 2016, HFPG became China's sixth leading cause of DALYs, and the attributable DALYs burden was 1802.3/100,000 population. Although the number of diabetes DALYs increased by 95% from 1990 to 2016, age-standardized diabetes DALYs rates increased by only 2.3%. Also, from 1990 to 2016, rates of age-standardized DALYs due to diabetes decreased in 14 provinces, but increased in 19 provinces. High BMI Scores and diets low in whole grains, nuts and seeds were the most important risk factors for diabetes in 2016.
Diabetes and hyperglycaemia constitute a huge health burden in China. The substantial increase in diabetes-related burden represents an ongoing challenge, given the rapidly ageing Chinese population. Thus, a targeted control and preventative strategy needs to be developed at risk factor level to reduce this burden.