Using salted egg white in steamed bread: Impact on functional and structural characteristics.

Steamed bread has long been an important part of Chinese cuisine. This study investigated the effects of salted egg white (SEW) (5, 10, 15, and 20% w/w) on the quality of steamed breads. Findings revealed that SEW notably enhanced the bread's volume and texture, with a 20% inclusion significantly boosting water retention and rheological properties, albeit reducing bread's lightness. In addition, the H-bond absorption band intensity in the Fourier transform infrared spectroscopy (FTIR) analysis showed increased peak intensities with higher SEW levels, indicative of protein structure alterations. X-ray diffraction confirmed the presence of an amylose-lipid complex. Scanning electron microscope (SEM) and Confocal laser scanning microscope (CLSM) imaging depicted a smooth, consistent protein network with SEW addition. Consumer sensory evaluation responded favourably to the SEW15 steamed bread, suggesting its potential for food industry application. Overall, the study considers SEW an effective ingredient for improving steamed bread quality.

The in vitro mechanism of Vaspinregulates the proliferation and steroidogenesis of rat lutein cells.

OBJECTIVE: Stable luteal cell function is an important prerequisite for reproductive ability and embryonic development. However, luteal insufficiency seriously harms couples who have the desire to have a pregnancy, and the most important thing is that there is no complete solution. In addition, Vaspin has been shown to have regulatory effects on luteal cells, but the complex mechanisms involved have not been fully elucidated. Therefore, this study aimed to explore the effect of Vaspin on rat luteal cells and its mechanism. METHODS: Granulosa lutein cells separated from the ovary of female rats were incubated for 24h with gradient concentrations of Vaspin, and granulosa lutein cells incubated with 0.5% bovine serum albumin were used as controls. The proliferation, apoptosis, angiogenesis, progesterone (P4) and estradiol (E2) were detected by CCK-8, Anneixn-FITC/PI staining, angiogenesis experiment and ELISA. Western blot was applied to observe the expression levels of proteins related to cell proliferation, apoptosis, angiogenesis and MEK/MAPK signaling pathway. RESULTS: Compared with the Control group, Vaspin could significantly up-regulate the proliferation of granulosa lutein cells and reduce the apoptosis. Moreover, Vaspin promoted the angiogenesis of granulosa lutein cells and the production of P4 and E2 in a concentration-dependent manner. Furthermore, Vaspin up-regulated the CyclinD1, CyclinB1, Bcl2, VEGFA and FGF-2 expression in granulosa lutein cells, and down-regulated the level of Bax. Also, Vaspin increased the p-MEK1 and p-p38 levels. CONCLUSION: Vaspin can up-regulate the proliferation and steroidogenesis of rat luteal cells and reduce apoptosis, which may be related to the influence of MEK/MAPK activity.

A Novel Food Bore Protein Hydrogel with Silver Ions for Promoting Burn Wound Healing.

Hydrogels have emerged as a promising option for treating local scald wounds due to their unique physical and chemical properties. This study aims to evaluate the efficacy of ovalbumin/gelatin composite hydrogels in repairing deep II-degree scald wounds using a mouse dorsal skin model. Trauma tissues collected at various time points are analyzed for total protein content, hydroxyproline content, histological features, and expression of relevant markers. The results reveal that the hydrogel accelerates the healing process of scalded wounds, which is 17.27% higher than the control group. The hydrogel treatment also effectively prevents wound enlargement and redness of the edges caused by infection during the initial stage of scalding. The total protein and hydroxyproline content of the treated wounds are significantly elevated. Additionally, the hydrogel up-regulates the expression of VEGF (a crucial angiogenic factor) and down-regulates CD68 (a macrophage marker). In summary, this study provides valuable insights into the potential of multifunctional protein-based hydrogels in wound healing.

Modified Tubeless Ureterocutaneostomy in High-Risk Patients After Radical Cystectomy and its Long-Term Clinical Outcomes.

OBJECTIVES: This work aimed to prevent stoma stenosis and achieve tubeless cutaneous ureterostomy in elderly and high-risk patients with our modified cutaneous ureterostomy. METHODS: We retrospectively analyzed 40 and 49 patients (176 renal units) who underwent Toyoda (group 1) and modified cutaneous ureterostomy (group 2) between 2012 and 2021. The average follow-up period was 44 months. The primary results of our study were the catheter-free rate and clinical outcomes, especially renal function and urinary diversion-related complications. Significant differences in catheter-free rate and urinary diversion-related complications were found between our modified method and the Toyoda technique. RESULTS: A total of 56 (71.8%) of 78 renal units in group 1 and 89 (90.8%) of 98 renal units in group 2 remained catheter free. Compared with group 1, group 2 had a higher catheter-free rate (P = .001). Multivariate analysis indicated that the surgical procedure (HR = 0.268; P = .001) and body mass index (HR = 3.127; P = .002) were the predictors independently associated with catheter insertion. During follow-up, renal deterioration was observed in 32 (36.0%) patients. Patients with catheter insertion were more likely to suffer from renal deterioration (P < .001), postoperative pyelonephritis (P < .001), and urolithiasis (P < .001) than their counterparts. CONCLUSION: Our modified cutaneous ureterostomy method may provide an effective and simple approach to tubeless cutaneous ureterostomy in elderly and high-risk patients.

MEHP activates JNK to inhibit the migration of human foreskin fibroblasts.

This study aimed to investigate the impact of mono(2-ethylhexyl) phthalate (MEHP) on the proliferation, apoptosis, and migration of human foreskin fibroblast cells (HFF-1) and the role of the JNK signaling pathway in cell migration. HFF-1 cells were randomly assigned to the control group with 0 MEHP exposure (M0) or the experimental groups with 25, 50, 100, 200, and 400 µmol/L MEHP exposure (M25, M50, M100, M200, and M400, respectively). After 24 and 48 h of MEHP exposure, the proliferation of HFF-1 cells in any group had no significant change. However, compared with the M0 group, the M200 and M400 groups presented substantially increased apoptosis of HFF-1 cells. Moreover, cell migration ability significantly decreased in all groups (p < 0.05). Additionally, the transcription and phosphorylated protein activation of JNK kinase in HFF-1 cells were substantially upregulated with the increase in MEHP exposure. Subsequently, HFF-1 cells were randomly divided into three groups: the DMSO blank control group, the 100 µM MEHP experimental group (M100), and the 100 µM MEHP plus 10 µM SP600125 (specific JNK inhibitor) experimental group (S10). The activation of JNK protein in HFF-1 cells was substantially downregulated in the S10 group. HFF-1 cells were also divided into the blank control group (M0). They were treated with 100 µM MEHP and varying concentrations of SP600125 (5, 10, and 15 µM for S5, S10, and S15, respectively). As the concentration of the antagonist increased, the migration ability of HFF-1 cells was returned to normal. Finally, the ROS in HFF-1 cells increased under MEHP exposure. This finding indicates that the regulation of cell migration by the JNK signaling pathway may be important in the occurrence of hypospadias.

A novel antibacterial hydrogel based on thiolated ovalbumin/gelatin with silver ions to promote wound healing in mice.

Hydrogels could be used as wound dressings, but most protein-based hydrogels lack anti-bacterial effects. Here, we successfully prepared a silver ion cross-linked thiolated protein hydrogel (thiolated Ovalbumin and Gelatin, O3G7). The wound photographs showed that the healing rate (96.23 %) of hydrogel-treated mice was higher than the control group. Meanwhile, the hydrogel increased the granulation tissue's total protein content. Furthermore, it significantly increased the collagen content, consistent with the results of Masson's trichrome (MT) staining and immunohistochemical analysis of type I collagen (ColI). The results of hematoxylin and eosin (H&E) staining showed the growth and proliferation of inflammatory cells, granulation tissue, fibroblasts, blood vessels and hair follicles in acute wounds. O3G7 hydrogel had fewer inflammatory cells and more neovascularization, and hair follicle tissue and intact epidermis could be observed. The results of immunofluorescence and immunohistochemistry showed that the O3G7 group reduced the expression of tumor necrosis factor (TNF)-α (56.87 % of the control group) and upregulated the expression of transforming growth factor (TGF)-ß (1.29 times of the control group). These results suggest that O3G7 hydrogel significantly affects the healing of acute wounds. This study demonstrates that hydrogels prepared from food-derived proteins will be promising and bio-safe candidates in bioengineering.

A hierarchical hub location model for the integrated design of urban and rural logistics networks under demand uncertainty.

This paper contributes to the integrated design issue of urban and rural logistics networks under demand uncertainty. A hierarchical hub location model is proposed, which minimizes the expected total system cost by optimizing the locations, number and capacities of "urban-town‒village" hierarchical logistics hubs. The interactions among the logistics hubs and among the hub‒and‒spoke connections, as well as the hub capacity constraints are explicitly considered in the presence of logistics demand uncertainty. A demand scenario‒based branch‒and‒Benders‒cut algorithm is developed to solve the proposed model. A case study of Jiangling urban‒rural region in Hubei province of China is conducted for the illustration of the model and solution algorithm. The results generated by the proposed algorithm are benchmarked against those obtained by GUROBI solver and the practical scheme being currently implemented in the region. The results showed that the proposed methodology can greatly improve the efficiency of the urban‒rural logistics system in terms of expected total system cost. It is important to explicitly model the demand uncertainty, otherwise a significant decision bias may emerge. The proposed algorithm outperforms the GUROBI solver in terms of problem size solved and computational time.

PFASs in Soil: How They Threaten Human Health through Multiple Pathways and Whether They Are Receiving Adequate Concern.

Per- and polyfluoroalkyl substances (PFASs) have been mass-produced and widely applied in consumer and industrial products, resulting in their widespread presence in the environment. Features such as environmental persistence, bioaccumulation, and high toxicity even at low doses have made PFASs an increasing concern. This brief review focuses on soil PFASs, especially the effect of soil PFASs on other environmental media and their potential threats to human health through daily diet. Specifically, soil PFASs contamination caused by different pathways was first investigated. Soil pollution from application of aqueous film-forming foams (AFFFs) is generally more severe than that from fluorochemical manufacturing plants, followed by biosolid land use, landfill, and irrigation. Factors, such as carbon chain length of PFASs, wastewater treatment technology, geographical conditions, and regional development level, are related to soil PFASs' pollution. Then, the migration, bioaccumulation, and toxicity characteristics of soil PFASs were analyzed. Short-chain PFASs have higher solubility, mobility, and bioavailability, while long-chain PFASs have higher bioaccumulation potential and are more toxic to organisms. Factors such as soil texture, solution chemistry conditions, enzymes, and fertilization conditions also influence the environmental behavior of PFASs. The risk of human exposure to PFASs through agricultural and animal products is difficult to control and varies depending on living region, age, eating habits, lifestyle, ethnicity, etc. Soil PFASs threaten drinking water safety, affect soil function, and enter food webs, threatening human health. Knowledge gaps and perspectives in these research fields are also included in current work to assist future research to effectively investigate and understand the environmental risks of soil PFASs, thereby reducing human exposure.

Air travel choice, online meeting and passenger heterogeneity - An international study on travellers' preference during a pandemic.

This study empirically identifies business travellers' preferences during the COVID-19 pandemic across different regions. A stated preference study was conducted during April to June 2021 on respondents in the U.S., the city of Shanghai in mainland China and Hong Kong. Generalised mixed multinomial logit (GMXL) models are estimated incorporating attributes of travel characteristics, severity levels of the pandemic, and health control measures at the airport. When an online meeting is inapplicable, respondents from Shanghai and Hong Kong highly value heath control measures, and are not sensitive to the time spent at airport health checkpoints. In comparison, U.S. respondents are averse to the time spent for health check, the reporting of personal information, travel history, symptoms, and the requirements of compulsory mask wearing and onsite sample testing. However, when online meeting is applicable, all the respondents show no appreciation for health control measures, while the U.S. respondents are twice more averse to the time spent at airport health checkpoints. Online meeting reduces the intention of international business travel amid the pandemic for passengers in Shanghai and Hong Kong, but imposes no significant effects on U.S. travellers. Such significant heterogeneity in traveller preference partly explains the different recovery patterns observed in various aviation markets, and justifies individualized travel arrangements and service priority in fulfilling pandemic control requirements across different regions. Our study also suggests that there are commonly accepted areas for global cooperation such as the sharing of vaccination record, and the option of online meeting calls for convenient travel arrangements amid pandemic to all countries.

The effect of online meeting and health screening on business travel: A stated preference case study in Hong Kong.

This study quantifies the effects of health control measures at the airport on passenger behaviour related to business travel. A stated preference survey was conducted over potential air travellers in Hong Kong in the context of COVID-19 pandemic. Panel latent class models were estimated to understand passenger preference toward new travel requirements given the applicability of online meeting. Online meeting is applicable in cases where it is a good substitute of air travel and achieves the same outcomes of a trip, and inapplicable otherwise. Empirical results indicate that traveller subgroups are affected in different ways. When an online meeting is inapplicable, nearly 75% of the respondents prefer to travel for business and undertake health screenings. These passengers (identified as "captive" business travellers) perceive such measures necessary to lower health related risks during air travel. As such, they are willing to spend up to 21 to 38 min on the health control measures such as vaccination record requirements and test involving sample collection. When an online meeting is applicable, the share of "choice" business travellers is about 45%, among whom the attitudes towards health control measures become more averse. The average weighted willingness-to-pay for the time saved at health checkpoints increase significantly. The aviation industry thus faces a "double-hit" problem: operation costs will increase due to pandemic control measures, and the resultant inconvenience, extra time and costs further reduces travel demand. Unlike previous short pandemics, business travel is likely to suffer with an extended decline until the pandemic is fully controlled. These identified challenges call for financial and operational support to help the aviation industry reach a sustainable "new normal". The high value of time saved at check points also justifies investments that make the pandemic control and health measures efficient and smooth. Travellers' time spent on airport health control should be within 20 min to avoid substantial negative impacts on business travel demand.

Rhizospheric mechanisms of Bacillus subtilis bioaugmentation-assisted phytostabilization of cadmium-contaminated soil.

Plant growth promoting (PGP) traits of inoculation in bioaugmentation assisted phytostabilization of heavy metal-contaminated soil have been well documented. The property of inoculation to immobilize heavy metals is another major contributor to phytostabilization efficiency. This study investigated the effects of inoculation with different concentrations of rhizobacteria Bacillus subtilis on the cadmium (Cd) bioavailability and distribution, enzyme activities, and bacterial community structure in soil planted with ryegrass (Lolium multiflorum L.). Addition of a high dosage of Bacillus subtilis decreased plant malondialdehyde (MDA) amount, increased plant antioxidant enzyme and soil nutrient cycling-involved enzyme activities, and subsequently enhanced biomass by 20.9%. In particular, the inoculation reduced the Cd bioavailability in soil, bioaccumulation coefficient (BCF), translocation factors (TF), and accumulation in ryegrass by 39.1%, 36.5%, 24.2%, and 27.9%, respectively. Furthermore, 16S rRNA gene sequencing analysis of rhizosphere soil revealed microbial community structure alterations (e.g., enrichment of Proteobacteria), eight phenotype regulations, and seventeen Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway transformations accounted for the stress mitigation and Cd immobilization in the presence of inocula. Besides, intracellular accumulation and biofilm sequestration were proposed as primary immobilization mechanisms induced by bioaugmentation.

Value of noncontrast computer tomography in predicting the characteristics of obstructive uropathy.

OBJECTIVE: To explore the diagnostic value of noncontrast computed tomography (NCCT) in differentiating pyonephrosis from nonpyogenic hydronephrosis on the basis of CT values (in Horsfield unit [HU]). METHODS: Data from patients diagnosed with obstructive uropathy at the First affiliated hospital of University of South China from November 2017 to January 2021 were subjected to retrospective analysis. In accordance with the gold standard-the presence of pus during the operation-all patients were divided into the nonpyogenic hydronephrosis group and the pyonephrosis group. The relationship between CT values and the presence or absence of pyonephrosis was performed using binary logistic regression. A receiver operating characteristic (ROC) curve was constructed to determine threshold values for classification on the basis of mean HU. RESULTS: A total of 207 patients, including 100 males and 107 females, were enrolled. Out of the 207 cases, 124 cases of obstructive uropathy were nonpyogenic hydronephrosis and 83 cases were of pyonephrosis. The CT values of the pyonephrosis group were significantly higher than that of the nonpyogenic hydronephrosis group (t = 9.15, P < 0.05). The CT values were dependent on the presence or absence of pyonephrosis (P < 0.05). A HU threshold value of 9.75 could be applied to diagnose the presence of pyonephrosis. CONCLUSION: The CT values of hydronephrosis might predict the presence of pyonephrosis in the kidney, and the CT value of 9.75 HU might be the appropriate threshold for its prediction.

A resampling approach to disaggregate analysis of bus-involved crashes using panel data with excessive zeros.

Public bus constitutes more than 70% of the overall road-based public transport patronage in Hong Kong, and its crash involvement rate has been the highest among all public transport modes. Though previous studies had identified explanatory factors that affect the crash risk of buses, use of considerably imbalanced crash data with excessive zero observations could lead to inaccurate parameter estimation. This study aims to resolve the excess zero problem of disaggregate analysis of bus-involved crashes based on synthetic data using a Synthetic Minority Over-Sampling Technique for panel data (SMOTE-P). Dataset comprising crash, traffic, and road inventory data of 88 road segments in Hong Kong during the period from 2014 to 2017 is used. To assess the data balancing performance, other common data generation approaches such as Random Under-sampling of the Majority Class (RUMC) technique, Cluster-Based Under-Sampling (CBUS), and mixed resampling, are also considered. Random effect Poisson (REP) models based on synthetic data and random effect zero-inflated Poisson (REZIP) model based on original data are estimated. Results indicate that REP model based on synthetic data using SMOTE-P outperforms REZIP model based on original data and REP models based on synthetic data using RUMC, CBUS and mixed approaches, in terms of statistical fit, prediction error, and explanatory factors identified. Results of model estimation based on SMOTE-P suggest that factors including morning peak, evening peak, hourly traffic flow, average lane width, road length, bus stop density, percentage of bus in the traffic stream, and presence of bus priority lane all affect the bus-involved crash frequency. More importantly, this study provides a feasible solution for disaggregate crash analysis with imbalanced panel data.

Biochemical mechanisms of rhizospheric Bacillus subtilis-facilitated phytoextraction by alfalfa under cadmium stress - Microbial diversity and metabolomics analyses.

The effects of Bacillus subtilis inoculation on the growth and Cd uptake of alfalfa were evaluated in this research using pot experiments, and the relevant biochemical mechanisms were first investigated by combined microbial diversity and nontarget metabolomics analyses. The results indicated that inoculation with alfalfa significantly decreased the amount of plant malondialdehyde (MDA) and improved the activities of plant antioxidant enzymes and soil nutrient cycling-involved enzymes, thereby promoting biomass by 29.4%. Inoculation also increased Cd bioavailability in rhizosphere soil by 12.0% and Cd removal efficiency by 139.3%. The biochemical mechanisms included enhanced bacterial diversity, transformed microbial community composition, regulated amounts of amino acids, fatty acids, carbohydrates, flavonoids and phenols in rhizosphere soil metabolites, and modulations of the corresponding Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. These responses were beneficial to microbial activity, nutrient cycling, and Cd mobilization, detoxification, and decontamination by alfalfa in soil. This study, especially the newly identified differential metabolites and metabolic pathways, provides new insights into mechanism revelation and strategy development in microbe-assisted phytomanagement of heavy metal-contaminated soils.

Effects of Salinity on the Biodegradation of Polycyclic Aromatic Hydrocarbons in Oilfield Soils Emphasizing Degradation Genes and Soil Enzymes.

The biodegradation of organic pollutants is the main pathway for the natural dissipation and anthropogenic remediation of polycyclic aromatic hydrocarbons (PAHs) in the environment. However, in the saline soils, the PAH biodegradation could be influenced by soil salts through altering the structures of microbial communities and physiological metabolism of degradation bacteria. In the worldwide, soils from oilfields are commonly threated by both soil salinity and PAH contamination, while the influence mechanism of soil salinity on PAH biodegradation were still unclear, especially the shifts of degradation genes and soil enzyme activities. In order to explain the responses of soils and bacterial communities, analysis was conducted including soil properties, structures of bacterial community, PAH degradation genes and soil enzyme activities during a biodegradation process of PAHs in oilfield soils. The results showed that, though low soil salinity (1% NaCl, w/w) could slightly increase PAH degradation rate, the biodegradation in high salt condition (3% NaCl, w/w) were restrained significantly. The higher the soil salinity, the lower the bacterial community diversity, copy number of degradation gene and soil enzyme activity, which could be the reason for reductions of degradation rates in saline soils. Analysis of bacterial community structure showed that, the additions of NaCl increase the abundance of salt-tolerant and halophilic genera, especially in high salt treatments where the halophilic genera dominant, such as Acinetobacter and Halomonas. Picrust2 and redundancy analysis (RDA) both revealed suppression of PAH degradation genes by soil salts, which meant the decrease of degradation microbes and should be the primary cause of reduction of PAH removal. The soil enzyme activities could be indicators for microorganisms when they are facing adverse environmental conditions.

Different transport behaviors and mechanisms of perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) in saturated porous media.

Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) in soil aroused increasing concern, however there is little information about their transport in porous media, which is urgently needed to better control their environmental risks. In this study, saturated sand columns (considering the coupled effect of solution cation type and pH) and a two-site nonequilibrium transport model (TSM) were used to investigate the transport behaviors and mechanisms of PFOA and PFOS. Breakthrough data and the TSM parameters showed PFOA had higher mobility than PFOS, and divalent cation could inhibit their transport by increasing the nonequilibrium interactions between them and the sand. pH had little influence on PFOA migration when there was only monovalent cation in the solution since PFOA had limited affinity with the sand, however, polyvalent cation could provide additional adsorption sites for it through cation bridging and enhance the effect of pH. Differently, decreasing pH inhibited the transport of PFOS more significantly, and the effect was stronger than that of changing cation type. That proved mechanisms like hydrogen-bonding which were sensitive to solution pH played an important role in PFOS migration. These results provide important scientific basis to the remediation strategy and the migration prediction model development of PFOA and PFOS.

Feedback of airborne bacterial consortia to haze pollution with different PM2.5 levels in typical mountainous terrain of Jinan, China.

Polluted air is as harmful as polluted water sources to public health. As air living organisms, the research on microbial consortia under haze stress with different PM2.5 levels in a mountainous environment remains very limited. This study investigated the dynamic changes in bacterial cell counts, apoptosis, human pathogens, consortia characteristics, metabolic pathways, and the biochemical functions under haze conditions with various degrees of pollution (leading pollutant PM2.5) from August to December 2017 in a typical mountainous terrain of Jinan, China. Samples were evaluated with flow cytometry and 16S rRNA gene amplicon sequencing. Results indicated that cell counts ranged from 6.83 × 105 ±â€¯1.27 × 104 (non-polluted air, NP) to 2.32 × 106 ±â€¯3.56 × 104 (heavily polluted air, HP) cell m-3 air. The proportion of viable apoptotic and necrotic cells were positively correlated to PM2.5. Burkholderia cenocepacia (36.6%) was the most abundant human pathogen found in HP; this gram-negative bacterium is associated with potentially lethal respiratory infections in cystic fibrosis patients. The relative abundance of the phylum Proteobacteria (63.8%) in NP first decreased in lightly polluted (LP) (41.3%) and moderately polluted air (MP) (26.3%) then increased in HP (81.0%). Cupriavidus (22.9%) and BTEX-degrading bacteria (0.6%, Pseudomonas) were found in HP. Metabolic pathways with significant differences included cell motility and endocrine and immune diseases that exhibited increasing relative abundance as pollution levels increased. The diversity of biochemical functions was found to be decreased in hazy air.

Transport of graphene oxide nanoparticles in saturated kaolinite- and goethite-coated sand columns: effects of low-molecular-weight organic acids.

The effects of low-molecular-weight organic acids (LMWOAs) on the transport of graphene oxide nanoparticles in saturated kaolinite- and goethite-coated sand columns were studied. Acetic acid, glycolic acid, malonic acid, and tartaric acid were chosen in the experiments. LMWOAs enhanced the mobility of GO by electrostatic/steric repulsion. In addition, they competed with GO for limited deposition sites on grain surfaces. The effects of organic acids on the transport of GO strongly depended on organic acid species. In general, the transport enhancement effects followed the order of tartaric acid > malonic acid > glycolic acid > acetic acid; this difference may be related to the number and type of functional groups of organic acids. Different LMWOAs enhanced the transport of GO in goethite-coated sand to a larger extent than did in kaolinite-coated sand under the test conditions; this was likely related to the differences of physicochemical characteristics between goethite and kaolinite. Organic acids significantly inhibited the deposition of GO at 0.5 mM Ca2+; this was possible that Ca2+ enhanced adsorption of organic acids by complexing with the surface O-functionalities of both LMWOAs and sand grain. Consequently, more organic acid molecules competed with GO for deposition sites on grain surfaces. Additionally, a two-site transport model was used to fit the transport data. Our findings have important implications for the understanding of the deposition and fate of GO in soil especially in rhizosphere environments where various low-molecular-weight organic acids are active.

Enzyme cocktail containing NADH regeneration system for efficient bioremediation of oil sludge contamination.

Oil sludge is one kind of toxic and persistent contamination to ecology system from petroleum industry. In order to recycle contaminated sands and reduce environmental impacts at a lower operating cost, enzyme cocktail 21/CbFDH including NADH regeneration system for oily sludge bioremediation was constructed for the first time. The intracellular enzymes of oil-degrading strain Acinetobacter calcoaceticus 21 were prepared and the formate dehydrogenase gene Cbfdh from Candida boidinii was cloned and functionally expressed in E.coli BL21 induced by lactose. The activity and stability of CbFDH was enhanced through self-induction medium optimization using Box-Behnken design. The CbFDH activity was 12.2 times increased and was only decreased 3.9% upon storage at 30 °C for 5 d. The CbFDH increased the degradation rate of oil in high concentration. For the sludge with 10% oil (w/w), the degradation rate achieved 35.6% after 12 h using enzyme 21/CbFDH with the protein ratio of 1:4. The results will provide novel perspectives for creation and operation of petroleum-degrading enzymes involving formate dehydrogenase with higher efficiency and lower cost comparing to current microbial strains or consortium.

Incorporating Bioaccessibility into Human Health Risk Assessment of Heavy Metals in Rice ( Oryza sativa L.): A Probabilistic-Based Analysis.

A systematic investigation into total and bioaccessible heavy metal concentrations in rice grains harvested from heavy metal-contaminated regions was carried out to assess the potential health risk to local residents. Arsenic, Cr, Cu, Pb, and Zn concentrations were within acceptable levels while Cd and Ni concentrations appeared to be much higher than in other studies. The bioaccessibity of As, Cd, and Ni was high (>25%) and could be well predicted from their total concentrations. The noncarcinogenic risk posed by As and Cd was significant. The carcinogenic risk posed by all bioaccessible heavy metals at the fifth percentile was 10-fold higher than the acceptable level, and Cd and Ni were the major contributors. The contribution of each metal to the combined carcinogenic risk indicates that taking pertinent precautions for different types of cancer, aimed at individuals with different levels of exposure to heavy metals, will greatly reduce morbidity and mortality rates.