Molecular characterization and expression profiling of two flavohemoglobin genes play essential roles in dissolved oxygen and NO stress in Saitozyma podzolica zwy2-3.

Flavohemoglobins (Fhbs) are key enzymes involved in microbial nitrosative stress resistance and nitric oxide degradation. However, the roles of Fhbs in fungi remain largely unknown. In this study, SpFhb1 and SpFhb2, two flavohemoglobin-encoding genes in Saitozyma podzolica zwy2-3 were characterized. Protein structure analysis and molecular docking showed that SpFhbs were conserved in bacteria and fungi. Phylogenetic analysis revealed that SpFhb2 may be acquired through the transfer event of independent horizontal genes from bacteria. The expression levels of SpFhb1 and SpFhb2 showed opposite trend under high/low dissolved oxygen, implying that they may exhibited different functions. Through deletion and overexpression of SpFhbs, we confirmed that SpFhbs were conducive to lipid accumulation under high stress. The sensitivities of ΔFhb mutants to NO stress were significantly increased compared with that in the WT, indicating that they were required for NO detoxification and nitrosative stress resistance in S. podzolica zwy2-3. Furthermore, SpAsg1 was identified that simultaneously regulates SpFhbs, which functions in the lipid accumulation under high/low dissolved oxygen and NO stress in S. podzolica zwy2-3. Overall, two different SpFhbs were identified in this study, providing new insights into the mechanism of lipid accumulation in fungi under high/low dissolved oxygen and NO stress.

Potential xylose transporters regulated by CreA improved lipid yield and furfural tolerance in oleaginous yeast Saitozyma podzolica zwy-2-3.

Lignocellulose's hydrolysate, a significant renewable source, contains xylose and furfural, making it challenging for industrial production of oleaginous yeast. On xylose fermentation with furfural treatment, OE::DN7263 and OE::DN7661 increased lipid yield and furfural tolerance versus WT, while, which of OE::CreA were decreased owing to CreA regulating DN7263 and DN7661 negatively. OE::CreA generated reactive oxygen species (ROS) causing oxidative damage. OE::DN7263, OE::DN7661, and ΔCreA reduced furfural via NADH; while ΔCreA produced less ROS and OE::DN7263, and OE::DN7661 scavenged ROS quickly, minimizing oxidative damage. Overall, CreA knockout increased DN7263 and DN7661 expression to facilitate xylose assimilation, enhancing NADH generation and ROS clearance. Finally, with mixed sugar fermentation, ΔCreA and OE::DN7263's biomass and lipid yield rose without furfural addition, while that of ΔCreA remained higher than WT after furfural treatment. These findings revealed how oleaginous yeast zwy-2-3 resisted furfural stress and indicated ΔCreA and OE::DN7263 might develop into robust industrial chassis strains.

[Analysis and Prediction of Health Risk from Heavy Metals in Drinking Water Sources Based on Time Series Model].

Health risk analysis can predict and control the risks posed by heavy metals, especially in drinking water, which is a highly sensitive environmental receptors. In order to evaluate heavy metal pollution in drinking water, the monthly average concentrations of As, Cd, Cu, Hg, Ni, and Zn were used to assess the health risk between January 2015 and December 2018 in a drinking water source. Furthermore, Spearman rank correlation coefficient and the ARIMA model were used to analyze temporal variations. The results showed that the monthly average concentrations of heavy metals exceeded the class Ⅲ values as specified by Chinese environmental quality standard for surface water(GB 3838-2002), especially Hg with a minimum monthly average four times more than that set by the standard limits. Overall, the order of carcinogenic risk of As and Cd was decreased; the non-carcinogenic risk of Zn, Cu, Ni, Pb, and Hg was increased. Further, the comprehensive non-carcinogenic risk for adults was lower than 1 throughout the study period except February 2015, when the comprehensive non-carcinogenic risk for children was lower than or close to 1 after October 2017, and the comprehensive carcinogenic risk for children was more than 10-4. Meanwhile, the children's health risks are higher than that for adults, with the main health risk characteristic factors of As, Cd, and Hg. The Spearman rank correlation coefficient were -0.714069, -0.773122, and -0.62234, indicating the significant downward trend from 2015 to 2018. However, the children's comprehensive carcinogenic risk, whose average value was 0.000234 much more than 10-4, had significant upward trend in 2018 with Spearman rank correlation coefficient 0.902098. The ARIMA(3,1,3) model was able to predict the comprehensive carcinogenic risk for children from heavy metals in drinking water, and the result indicated the children comprehensive carcinogenic risk should be monitored to ensure levels between 0.000200 and 0.000302. The study has positive significance for risk warning and environmental management compared to the analysis and prediction of health risk from heavy metals in drinking water sources based on time series models.

Method for absolute measurement of flat surface.

Interferometry is a relative measurement method for optical surface testing, and thus its testing accuracy depends on the accuracy of the reference surface. Absolute measurement is one of the most effective methods to improve the testing accuracy in interferometry. We present an efficient absolute measurement method based on Zernike polynomial fitting algorithms. With our proposed method, the profiles of both the test surface and the reference surface can be calculated simultaneously. We further carried out simulation analysis to scientifically evaluate the test accuracy of the proposed method. Finally, we conducted actual experiments to demonstrate the feasibility and practicability of our method.

[Assessment and Spatial Characteristics Analysis of Human Health Risk of Heavy Metals in Cultivated Soil].

Spatial characteristics analysis of the human health risk posed by heavy metals in cultivated soils is of great significance, with the potential to prevent and control soil pollution, protect human health, provide a basis for risk management, etc. In this paper, a methodological system, including a USEPA health risk assessment model, differentiation and factor detector within a geographical detector, and optimized initial model of rank-size theory, was constructed from a geographical perspective. Taking a city in Jiangsu province as the research object, we obtained the spatial differentiation and relative level of human health risk of Cr, Pb, Hg, and Cd in cultivated land by using the methodological system constructed and SPSS and ArcGIS software. The average concentrations of heavy metals (mg·kg-1) in the research area were Cr (65.207 mg·kg-1), Pb (25.486 mg·kg-1), Cd (0.238 mg·kg-1), and Hg (0.045 mg·kg-1), which were lower than the risk control standards for soil contamination of agricultural land in China. The children's non-cancer risk of Cr and Pb and the cancer risk to children and adults of Cr were 2.914385, 1.337503, 4.312679×10-6, and 8.137130×10-6, respectively, all of which exceeded the maximum acceptable limit in the research. Meanwhile, the spatial differentiation (q) of heavy metal health risk was between 0.005523 and 0.204238, which indicated that the high health risk posed by heavy metals should be paid attention to. The health risk rankings (R) of the children's non-cancer risk of Cr and Pb and the cancer risk of Cr in subregions 1, 2, 3, and 4 approached or exceeded 1, and were higher than in subregions 5, 6, and 7, for which R was lower than 0.1. The R values indicated than the high health risk is concentrated in the research region. This research has great significance in measuring the health risk of heavy metals in cultivated soil at different scales, and in forming control strategies with local conditions.

Green infrastructure practices simulation of the impacts of land use on surface runoff: Case study in Ecorse River watershed, Michigan.

As an urban fringe district, the Ecorse River watershed is faced with increased impervious area caused by urban expansion. Effects of Green Infrastructure (GI) practice implementation were simulated with the Long-Term Hydrologic Impact Assessment-Low Impact Development 2.1 model (L-THIA-LID 2.1). Suitable locations of each GI practice were identified, based on construction condition requirements and demand on GI practices in the study area. Using the data of 2011, various GI practice combination scenarios were explored according to the cost-efficiency of each GI practice. GI practice implementation scenarios in 2050 were also simulated based on projected land use and rainfall data. Results show that grassed swales, rain barrels (residential areas) and dry ponds were the top three most cost-efficient GI practices, with the cost at $1.5/m³/yr, $3.0/m³/yr and $3.4/m³/yr, respectively. Green roofs with rain cisterns (industrial and commercial area) were the most expensive GI practices, with the cost at $92.9/m³/yr. With the increase of investment in GI practices, the changing curves of the annual runoff volume, Total Nitrogen (TN) load and Total Phosphorus (TP) load reduction ratios match the law of diminishing marginal utility. The scenario with grassed swales, rain barrels, dry ponds and porous pavement would be the most cost-efficient scenario for runoff water quantity reduction. In addition, the scenario with additional wet ponds would be the most cost-efficient one for TN load and TP load reduction. GI practices in each scenario for expected 2050 conditions show better effectiveness on water quantity and quality management.

A new multichannel spectral imaging laser scanning confocal microscope.

We have developed a new multichannel spectral imaging laser scanning confocal microscope for effective detection of multiple fluorescent labeling in the research of biological tissues. In this paper, the design and key technologies of the system are introduced. Representative results on confocal imaging, 3-dimensional sectioning imaging, and spectral imaging are demonstrated. The results indicated that the system is applicable to multiple fluorescent labeling in biological experiments.

Overexpression of Evi-1 oncoprotein represses TGF-ß signaling in colorectal cancer.

Human colorectal cancer (CRC) cells are resistant to the anti-proliferative effect of transforming growth factor-ß (TGF-ß), suggesting that disruption of TGF-ß signaling plays an important role in colorectal carcinogenesis. Ecotropic virus integration site-1 (Evi-1) oncoprotein represses TGF-ß signaling by interacting with Smads, but its role in CRC has not been established. The purpose of this study is to determine whether Evi-1 plays role(s) in CRCs and to characterize Evi-1 transcript(s) in CRCs. Evi-1 was overexpressed in 53% of human CRC samples, 100% of colon adenoma samples, and 100% of human colon cancer cell lines tested. Using 5' RACE, we cloned a novel Evi-1 transcript (Evi-1e) from a human CRC tissue and found that this novel transcript was expressed at a higher level in CRC tissues than in normal tissues and was the major Evi-1 transcript in CRCs. Transient Evi-1 transfection inhibited TGF-ß-induced transcriptional activity and reversed the growth inhibitory effect of TGF-ß in MC-26 mouse colon cancer cells. In conclusion, we have identified overexpression of Evi-1 oncoprotein as a novel mechanism by which a subset of human CRCs may escape TGF-ß regulation. We have also identified a novel Evi-1 transcript, Evi-1e, as the major Evi-1 transcript expressed in human CRCs.

Bombesin enhances TGF-beta growth inhibitory effect through apoptosis induction in intestinal epithelial cells.

Mammalian intestinal epithelium undergoes continuous cell turn over, with cell proliferation in the crypts and apoptosis in the villus. Both transforming growth factor (TGF)-beta and gastrin-releasing peptide (GRP) are involved in the regulation of intestinal epithelial cells for division, differentiation, adhesion, migration and death. Previously, we have shown that TGF-beta and bombesin (BBS) synergistically induce cyclooxygenase-2 (COX-2) expression and subsequent prostaglandin E(2) (PGE2) production through p38(MAPK) in rat intestinal epithelial cell line stably transfected with GRP receptor (RIE/GRPR), suggesting the interaction between TGF-beta signaling pathway and GRPR. The current study examined the biological responses of RIE/GRPR cells to TGF-beta and BBS. Treatment with TGF-beta1 (40 pM) and BBS (100 nM) together synergistically inhibited RIE/GRPR growth and induced apoptosis. Pretreatment with SB203580 (10 microM), a specific inhibitor of p38(MAPK), partially blocked the synergistic effect of TGF-beta and BBS on apoptosis. In conclusion, BBS enhanced TGF-beta growth inhibitory effect through apoptosis induction, which is at least partially mediated by p38(MAPK).

TGF-beta signaling in colon cancer cells.

Transforming growth factor-betas (TGF-betas), cytokines expressed in the colon, play important roles as tumor suppressors and tumor promoters during colorectal carcinogenesis. TGF-beta signaling pathway involves activation of Smad2 and Smad3 by the type I receptor and formation of Smad2/3/4 heteromeric complexes that enter the nucleus to regulate transcription. Most human colorectal cancers are resistant to the tumor suppressor effects of TGF-beta, and a subset of human colorectal cancers have mutations in Smad2 and Smad4. The purpose of this study was to determine whether Smads are required for TGF-beta signaling in colon cancer cells. First, we selected a colon cancer cell line (MC-26) that has a functional TGF-beta signaling pathway. We found that MC-26 cells expressed Smad2, Smad3, and Smad4 mRNAs by reverse transeription-polymerase chain reaction and confirmed that the TGF-beta signaling pathway is functional using a transient transfection assay with 3TP-Lux reporter plasmid. TGF-beta also inhibited cell growth and induced apoptosis in MC-26 cells. When MC-26 cells were transiently transfected with dominant-negative carboxyl-terminal truncation mutants of Smad2, Smad3, and Smad4, TGF-beta-induced 3TP-Lux reporter activity was significantly reduced, suggesting that Smad2, Smad3, and Smad4 are attractive novel therapeutic targets for regulating TGF-beta signaling in colorectal cancers. Because MC-26 cells express TGF-beta activated Smads, have a functional TGF-beta signaling pathway, and are sensitive to the growth inhibitory and apoptotic effects of TGF-beta, they can serve as an excellent model to examine TGF-beta signaling in colorectal cancers.