Understanding the pivotal role of ubiquitous Yellow River suspend sediment in efficiently degrading metronidazole pollutants in water environments

Sulfite-based advanced oxidation technology has received considerable attention for its application in organic pollutants elimination. However, the potential of natural sediments as effective catalysts for sulfite activation has been overlooked. This study investigates a novel process utilizing suspended sediment/sulfite (SS/S(IV)) for degradation of metronidazole (MNZ). Our results demonstrate that MNZ degradation efficiency can reach to 93.1 % within 90 min with 12.0 g SS and 2.0 mM sulfite. The influencing environmental factors, including initial pH, SS dosage, S(IV) concentration, temperature, and co-existing substances were systematically investigated. Quenching experiments and electron paramagnetic resonance analyses results indicate that SO3•- is the primary active substance responsible for MNZ degradation, with involvement of SO4•-, SO5•-, and •OH. X-ray photoelectron spectroscopy and Mössbauer spectra reveal that Fe (III)-silicates play a crucial role in activating S(IV). Furthermore, analysis of degradation intermediates and pathways of MNZ is conducted using liquid chromatography with mass spectrometry (LC -MS). The toxicity of MNZ and its intermediates were also systematically evaluated by the T.E.ST. program and wheat seeds germination test. This study offers valuable insight into the activation of sulfite by natural sediments and could contribute to the development of SS-based advanced oxidation processes (AOPs) for the in-situ remediation of antibiotics-contaminated water environments.

The Fate of Microplastics, Derived from Disposable Masks, in Natural Aquatic Environments

This paper mainly reviews the fate of microplastics, released from used face masks, in the water environment. Through previous experiments, the amount of fiber microplastics released from used face masks into aqueous environments was not negligible, with the maximum microplastics releasing amount reaching 10,000 piece·day-1 for each mask. Microplastic derived from these masks often occurred in the shape of polymeric fibers that resulted from the breakage of the chemical bonds in the plastic fibers by the force of water flow. The potential contact forces between microplastics (originating from face masks) with other pollutants, primarily encompass hydrophobic and electrostatic interactions. This critical review paper briefly illustrates the fate of microplastics derived from disposable face masks, further devising effective strategies to mitigate the environmental impact of plastic particle release from the used personal protective equipment.

Incorporating carbon sequestration toward a water-energy-food-carbon planning with uncertainties

Water-energy-food nexus (WEFN) is the core content in the United Nations 2030 Agenda for Sustainable Development. However, the value of soil and crops' carbon sink function has not yet been fully considered in the managment practices of WEFN system. Here, we developed a water-energy-food-carbon nexus (WEFCN) planning framework that incorporates carbon sequestration and multiple mathematical optimization methods into the practical WEFN management for Henan Province, which is one of major grain-producing areas in China. Uncertainties from multiple objectives, scenarios, and different stakeholder interests are captured. We found that wheat has the largest carbon sequestration, followed by corn and oil-bearing crops, while other crops have implicit carbon sequestration. Since chemical fertilizer produces the most carbon emissions, the usage of chemical fertilizer needs to be reasonably controlled. Overall, the proposed framework supports optimal decision-making for regional-scale WEFCN management and further unlocks the hidden value of agricultural carbon mitigation.

Study of the adsorption behavior of tetracycline onto suspended sediments in the Yellow River, China: Insights into the transportation and mechanism

The increasing usage of household drugs has contributed to the widespread distribution of antibiotic pollutants in the aquatic environment. Although previous studies have proven that sediments could act as an important transport vector of antibiotic pollutants, the crucial impact of suspended sediments (SS) on the migration and fate of antibiotics in water bodies remain unclear. This study systematically investigated the performance and potential mechanism of the adsorption of tetracycline (TC) on SS in the Yellow River. The results show that physisorption (pore filling, hydrogen bonding) and chemisorption (π-π interaction, surface complexation, and electrostatic interaction) activities contributed to the adsorption of TC onto SS. The mineral components (SiO₂, Fe₂O₃, and Al₂O₃) of SS were found to be the main active sites for TC adsorption. The contribution of SiO₂, Fe₂O₃, and Al₂O₃ to the overall TC adsorption could reach up to 5.6 %, 0.4 %, and 73.3 %, respectively. Interestingly, the DFT results suggesting that SiO₂ tends to form intermolecular hydrogen bonds with TC, while FeO and AlO play predominant roles in TC adsorption on SS. The MIKE simulations showed that river temperature, initial pH, and SS concentration would significantly affect the concentration of dissolved TC during SS transport. In addition, the presence of humic acid and more acidic environments favored the adsorption of TC on SS. Conversely, the introduction of inorganic cations inhibited the adsorption of TC on SS. This study provides new insights into the adsorption mechanism and migration of antibiotics in rivers with high SS content.

Synthesis and Peroxide Activation Mechanism of Bimetallic MOF for Water Contaminant Degradation: A Review

Metal-organic framework (MOF) materials possess a large specific surface area, high porosity, and atomically dispersed metal active sites, which confer excellent catalytic performance as peroxide (peroxodisulfate (PDS), peroxomonosulfate (PMS), and hydrogen peroxide (H₂O₂)) activation catalysts. However, the limited electron transfer characteristics and chemical stability of traditional monometallic MOFs restrict their catalytic performance and large-scale application in advanced oxidation reactions. Furthermore, the single-metal active site and uniform charge density distribution of monometallic MOFs result in a fixed activation reaction path of peroxide in the Fenton-like reaction process. To address these limitations, bimetallic MOFs have been developed to improve catalytic activity, stability, and reaction controllability in peroxide activation reactions. Compared with monometallic MOFs, bimetallic MOFs enhance the active site of the material, promote internal electron transfer, and even alter the activation path through the synergistic effect of bimetals. In this review, we systematically summarize the preparation methods of bimetallic MOFs and the mechanism of activating different peroxide systems. Moreover, we discuss the reaction factors that affect the process of peroxide activation. This report aims to expand the understanding of bimetallic MOF synthesis and their catalytic mechanisms in advanced oxidation processes.

Application and Comparison of Different Models for Quantifying the Aquatic Community in a Dam-Controlled River

In order to develop a better model for quantifying aquatic community using environmental factors that are easy to get, we construct quantitative aquatic community models that utilize the different relationships between water environmental impact factors and aquatic biodiversity as follows: a multi-factor linear-based (MLE) model and a black box-based 'Genetic algorithm-BP artificial neural networks' (GA-BP) model. A comparison of the model efficiency and their outputs is conducted by applying the models to real-life cases, referring to the 49 groups of seasonal data observed over seven field sampling campaigns in Shaying River, China, and then performing model to reproduce the seasonal and inter-annual variation of the water ecological characteristics in the Huaidian (HD) site over 10 years. The results show that (1) the MLE and GA-BP models constructed in this paper are effective in quantifying aquatic communities in dam-controlled rivers; and (2) the performance of GA-BP models based on black-box relationships in predicting the aquatic community is better, more stable, and reliable; (3) reproducing the seasonal and inter-annual aquatic biodiversity in the HD site of Shaying River shows that the seasonal variation of species diversity for phytoplankton, zooplankton, and zoobenthos are inconsistent, and the inter-annual levels of diversity are low due to the negative impact of dam control. Our models can be used as a tool for aquatic community prediction and can become a contribution to showing how quantitative models in other dam-controlled rivers to assisting in dam management strategies.

A Comprehensive Exploration on Occurrence, Distribution and Risk Assessment of Potentially Toxic Elements in the Multi-Media Environment from Zhengzhou, China

Road dust (RD), roadside soils (RS) and river surface sediments (sediments) are important materials for evaluating contaminant levels in urban areas. This study aims to investigate the contaminant characteristics, pollution levels and ecological risks of RD, RS and sediments of potentially toxic elements (PTEs), including Cr, Ni, Cu, Zn, As, Cd, Hg and Pb, in the central urban area of Zhengzhou. Results reveal that RD shows a higher concentration of PTEs when compared to the other two environments. The spatial distribution characteristics suggest that PTEs in RD, RS and sediments may come from different sources. The geo-accumulation index (I_geo) was used to describe that the RD was moderately to extremely contaminated with Cd and Hg, while both RS and sediments were significantly enriched with Cd and Hg. For RD, RS and sediments, the potential ecological risk (RI) demonstrates a high potential ecological risk from Cd and Hg. Overall, PTEs in Zhengzhou road dust present a moderate risk.

The Potential of Spent Coffee Grounds @ MOFs Composite Catalyst in Efficient Activation of PMS to Remove the Tetracycline Hydrochloride from an Aqueous Solution

The efficient removal of Tetracycline Hydrochloride (TC) from wastewater, which is a difficult process, has attracted increasing attention. Aiming to synchronously achieve the goal of natural waste utilization and PMS activation, we have combined the MOFs material with waste coffee grounds (CG). The catalytic activity of the CG@ZIF-67 composite in the TC removal process was thoroughly evaluated, demonstrating that the TC removal rate could reach 96.3% within 30 min at CG@ZIF-67 composite dosage of 100 mg/L, PMS concertation of 1.0 mM, unadjusted pH 6.2, and contact temperate of 293.15 K. The ¹O₂ and ·SO₄^- in the CG@ZIF-67/PMS/TC system would play the crucial role in the TC degradation process, with ¹O₂ acting as the primary ROS. The oxygen-containing functional groups and graphite N on the surface of CG@ZIF-67 composite would play a major role in efficiently activating PMS and correspondingly degrading TC. In addition, the CG@ZIF-67/PMS/TC system could withstand a wide pH range (3-11). The application of CG in preparing MOF-based composites will provide a new method of removing emerging pollutants from an aqueous solution.

Evaluation of aquatic ecological health of sluice-controlled rivers in Huai River Basin (China) using evaluation index system

The aquatic ecological health status was focused on the Huai River Basin (HRB) from the aspects of water quantity, water quality, water ecology, river connectivity, and riparian habitat environment. Ten monitoring sections were set up in the middle and upper reaches of HRB, and 5 experiments of each section were conducted in July and December from 2012 to 2014. Thus, relevant data on the species, the density of phytoplankton, zooplankton and benthic animals, the concentration of water physicochemical variables, and riparian habitat quality were obtained. Eleven key impact factors were chosen using frequency statistics, theoretical analysis, and correlation analysis methods, forming the evaluation index system of aquatic ecological health. Then, the indicator weight value was determined by the combined weight method, and the health degree was evaluated by the comprehensive index method. On the whole, the aquatic ecological health degree of the upper sections (D1 ~ D3) of the Shaying River ranges from 0.334 to 0.927, which is generally in a "sub-healthy" state. The aquatic ecological health degree of the main section of the Huai River (D8 ~ D10) ranges from 0.362 to 0.777, which is in the "critical" or "sub-healthy" state. The Huaidian Sluice (D5) and Fuyang Sluice (D6) in the middle and lower reaches of the Shaying River had the worst aquatic ecological health. Its water ecological health range is 0.283-0.523, and most of them are under "sub-pathologic." The research results have important theoretical and practical significance. They can enrich the evaluation theories and methods of river aquatic ecological health, help to grasp the aquatic ecological health status in HRB, and provide basic support for aquatic ecological protection and water pollution control in sluice-controlled rivers.

A nomogram integrating ferroptosis-and immune-related biomarker for prediction of prognosis and diagnosis in kidney renal clear cell carcinoma

OBJECTIVE

Approximately 60% of patients with kidney renal clear cell carcinoma (KIRC) die within the first 2-3 years. The prognosis for patients with KIRC and its metastases is poor. Ferroptosis and providing immunity are novel treatment targets for several cancers, including KIRC. Therefore, it is important to identify suitable ferroptosis- and immune-related signatures to predict the prognosis and diagnosis of patients with KIRC.

MATERIALS AND METHODS

The corresponding data of patients with KIRC were obtained from the Cancer Genome Atlas. Univariate and multivariate Cox regression analyses were used to screen candidate biomarkers in patients with KIRC.

RESULTS

We found that four FI-DEGs (BID, MET, LTB4R, and HMOX1) were independently associated with the overall survival of patients with KIRC. The prognosis and diagnosis model constructed using these four biomarkers could predict the outcome of KIRC, as measured by the receiver operating characteristic analyses.

CONCLUSIONS

We identified 4 FI-DEGs that could be used as biomarkers in patients with KIRC. The present study not only contributes to understanding the roles of ferroptosis and immunity in the development of KIRC, but also to the diagnosis and prognosis of KIRC, although it remains to be further studied.

The potential of green biochar generated from biogas residue as a heterogeneous persulfate activator and its non-radical degradation pathways: Adsorption and degradation of tetracycline

Advanced oxidation aided by sulfate radicals (SO₄^-) is an effective option for the treatment of refractory pollutants from aqueous solutions. In this work, a metal-free biochar catalyst was prepared using pyrolyzed biogas residue as the raw material. The biogas residue carbon (BRC) obtained at 800 °C showed excellent catalytic activity and adsorption capacity for the removal of tetracycline (TC) with 97.9% of removal efficiency. Such performance is accounted for by the rich pores and accelerated electron transformability conferred by its defect structure with the crucial role of pyrolysis temperature in regulating catalyst properties. The BRC-800/peroxymonosulfate (PMS) system worked predominantly through non-radical pathways with high stability/recyclability without being interfered by organic/inorganic compounds in an actual water environment. The exceelent removal performance is also supported by the kinetic reaction rate of the BRC-800/PMS system as estimated to be 0.03017 min^-1. This work provides a simple and effective path for modifying biogas residue waste for versatile applications.

A comprehensive exploration on distribution, risk assessment, and source quantification of heavy metals in the multi-media environment from Shaying River Basin, China

Comprehensively understand the distribution of pollutants in the multi-media environment at basin scale is of major importance to the ecological risk assessment and pollution control. In this study, multi-media contamination characteristics of eight heavy metals in the water, soil, and sediment from the Shaying River Basin of China have been analyzed to probe their ecological risks and potential sources. Results revealed that heavy metal concentrations in pore water were higher than those in surface water. While the mean concentrations of most heavy metals increased follow the order of bankside soil (BS)<water-level-fluctuating zone soil (WLFZS)<sediment. The WLFZ was an important transition zone between the BS and sediment for pollutant exchange. The mean heavy metal concentrations in surface water were all below their corresponding water quality standards except Hg. Whereas the mean concentrations of Cr, Ni, Zn, Cd, and Hg in BS, WLFZS, and sediment exceeded their corresponding background values. The assessment results of pollution and risks indicated that Hg and Cd posed the highest potential risks in each medium. Furthermore, according to the factor analysis and PMF model, six potential sources were identified, in which agricultural, fuel combustion, and industrial sources were the dominant anthropogenic sources, accounting for 23.84%, 17.43%, and 14.25% of the total contribution.

Iodine Modifies the Susceptibility of Thyroid to Fluoride Exposure in School-age Children: a Cross-sectional Study in Yellow River Basin, Henan, China

Excessive fluoride exposure has detrimental effects on the thyroid gland, which may be modified by iodine. However, the role of iodine in it remains unclear. This study aims to evaluate the role of iodine in thyroid abnormalities caused by fluoride exposure in school-age children. A total of 446 children aged 7-12 years were recruited from Tongxu County, Henan province, in 2017 (ZZUIRB 2017-018). We obtained demographic information through questionnaire surveys. The concentrations of urinary fluoride (UF) and urinary iodine (UI) were determined by the ion-selective electrode method and the catalytic spectrophotometric method, respectively. The radiation immunoassay was used to determine the serum concentrations of total triiodothyronine (TT3), total thyroxine (TT4), and thyroid-stimulating hormone (TSH). The B-mode ultrasound was performed to assess thyroid volumes (Tvols). The associations between fluoride exposure and thyroid-related indicators were tested by linear regression models. We found that Tvols increased by 0.22 (95% CI: 0.14, 0.31) cm³ with each standard deviation increment of UF. Moreover, Tvols in boys were more susceptible to fluoride exposure than those in girls, and the Tvols of children with high urinary iodine are less susceptible to fluoride exposure (P for interaction < 0.05). We also observed that TT3 levels were negatively related to UF concentrations at moderate urinary iodine levels (≤ 300 μg/l). Fluoride exposure can elevate the Tvols of school-age children, especially in boys, and high levels of iodine may alleviate this effect to some extent.

The potential of microplastics as adsorbents of sodium dodecyl benzene sulfonate and chromium in an aqueous environment

Considering the omnipresence of microplastics (MPs) in aquatic environments, they are expected to exert significatn impacts as carriers for diverse waterborne pollutants. In this work, the adsorptive behavior of two ionic components (i.e., sodium dodecyl benzene sulfonate (SDBS) and Cr(VI)) has been explored against the two types of MPs as model adsorbents, namely poly (ethylene terephthalate) (PET) and polystyrene (PS). The influence of key variables (e.g., pH, particle size, and dose of the MPs) on their adsorption behavior is evaluated from various respects. The maximum adsorption capacity values of SDBS on PET and PS are estimated to be 4.80 and 4.65 mg⋅g^-1, respectively, while those of Cr(VI) ions are significantly lower at 0.080 and 0.072 mg⋅g^-1, respectively, The adsorptive equilibrium of SDBS is best described in relation to pH and MP size by a Freundlich isotherm. In contrast, the adsorption behavior of Cr(VI) is best accounted for by a Langmuir isotherm to indicate its adsorption across at least two active surface sites.

Effects of filtration-induced size change on the subsequent transport and fate of graphene oxide in saturated porous media

A particle size change occurs ubiquitously during transport of nanoparticles in the subsurface and is likely to influence nanoparticle fate and transport behaviours. The effects of this size change on the subsequent transport of eluted graphene oxide (GO) in saturated media were therefore investigated under various ionic strength (IS) and filtration degree conditions. Aggregation kinetics revealed that size change after filtration only occurred at relatively high IS conditions. As the filtration column length increased from 15 cm to 30 cm, sizes of aggregates in filtrates for large-sized and small-sized GO populations decreased and increased, respectively, and both approached to their steady aggregate sizes. Aggregation, straining, sedimentation, bridging, DLVO interactions, or a combination of these mechanisms were involved in the size change process during filtration. After passing through the 30 cm filtration column, filtered GO, in comparison with original GO, exhibited stronger mobility than expected, suggesting neglecting size change will result in underestimation of the nanoparticle mobility in porous media.

Effect of biochar on Cd and pyrene removal and bacteria communities variations in soils with culturing ryegrass (Lolium perenne L.)

Organic contaminations and heavy metals in soils cause large harm to human and environment, which could be remedied by planting specific plants. The biochars produced by crop straws could provide substantial benefits as a soil amendment. In the present study, biochars based on wheat, corn, soybean, cotton and eggplant straws were produced. The eggplant straws based biochar (ESBC) represented higher Cd and pyrene adsorption capacity than others, which was probably owing to the higher specific surface area and total pore volume, more functional groups and excellent crystallization. And then, ESBC amendment hybrid Ryegrass (Lolium perenne L.) cultivation were investigated to remediate the Cd and pyrene co-contaminated soil. With the leaching amount of 100% (v/w, mL water/g soil) and Cd content of 16.8 mg/kg soil, dosing 3% ESBC (wt%, biochar/soil) could keep 96.2% of the Cd in the 10 cm depth soil layer where the ryegrass root could reach, and it positively help root adsorb contaminations. Compared with the single planting ryegrass, the Cd and pyrene removal efficiencies significantly increased to 22.8% and 76.9% by dosing 3% ESBC, which was mainly related with the increased plant germination of 80% and biomass of 1.29 g after 70 days culture. When the ESBC dosage increased to 5%, more free radicals were injected and the ryegrass germination and biomass decreased to 65% and 0.986 g. Furthermore, when the ESBC was added into the ryegrass culture soil, the proportion of Cd and pyrene degrading bacteria Pseudomonas and Enterobacter significantly increased to 4.46% and 3.85%, which promoted the co-contaminations removal. It is suggested that biochar amendment hybrid ryegrass cultivation would be an effective method to remediate the Cd and pyrene co-contaminated soil.

A novel chitosan-vanadium-titanium-magnetite composite as a superior adsorbent for organic dyes in wastewater

In this research, a novel chitosan (CS)-vanadium-titanium-magnetite (VTM) composite was designed and synthesized. The interaction between CS-VTM and Congo red (CR) dye conformed to a pseudo-second-order model to support the potent involvement of chemisorption. The effects of adsorbent dosage, reaction temperature, and initial solution pH on adsorption of CR were investigated. Approximately 99.1% of CR (100 mg/L) was adsorbed at a CS-VTM dose of 2.0 g/L or above, while such a reaction was favored at temperatures of 65 °C and pH of 6.0. Thermodynamically, the adsorption of CR proceeded spontaneously (ΔG < 0) above 35 °C. According to scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectrometer, and zeta potential analysis, its adsorption on CS-VTM can be attributed to electrostatic attraction and hydrogen bonds. The prepared CS-VTM exhibited superior adsorption performance on removal of CR as evidenced by significantly large partition coefficient of 108.3 mg g^-1 μM^-1 (equilibrium adsorption capacity of 62.2 mg/g at CR dose of 100 mg/L). Overall, the CS-VTM proved to be a promising and environmentally friendly adsorbent for the highly efficient and effective removal of organic dyes among the comparable sorbents studied to date.

Fe3O4 nanoparticles loading on cow dung based activated carbon as an efficient catalyst for catalytic microbubble ozonation of biologically pretreated coal gasification wastewater

Cow dung based activated carbon was successfully modified by Fe₃O₄ nanoparticles as the novel catalyst (Fe₃O₄ nanoparticles@CDAC) to improve the microbubble ozonation treating biologically pretreated coal gasification wastewater (BPCGW). When the pH, ozone dosage, ozone bubble diameter and catalyst dosage of the ozonation were 7, 0.4 L/min, 5 μm and 3 g/L, the chemical oxygen demand (COD) removal efficiency reached 74% and the ratio of biochemical oxygen demand in five days/COD (BOD₅/COD) increased from 0.04 to 0.52, which were attributed to the electron transfer of Fe²⁺ and Fe³⁺ in Fe₃O₄ and enhanced hydroxyl radicals generation by the reaction of iron ions and ozone. Meanwhile, benzene derivatives, naphthalene and aromatic proteins were significantly removed while multiple chain hydrocarbons and their derivatives composed the main residual organic matters. The catalytic activity was slightly decreased even the catalyst has been reused for five times. Therefore, catalytic microbubble ozonation using Fe₃O₄ nanoparticles@CDAC represented excellent performance treating BPCGW and it is a promising process for wastewater advanced treatment.

Toxicological Assessment of Ammonia Exposure on Carassius auratus red var. Living in Landscape Waters

To understand the toxic mechanism of ammonia and identify effective biomarkers on the oxidative stress for the fish Carassius auratus red var., acute and chronic toxicity tests were conducted. The 96-h LC₅₀ of total ammonia nitrogen (TAN) for C. auratus was 135.4 mg L^-1, the corresponding unionized ammonia (NH₃) concentration was 1.5 mg L^-1. The activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), glutathione-peroxidase (GSH-Px) and glutathione (GSH) showed an increase with a subsequent falling, while the malondialdehyde (MDA) increased during the chronic test. The SOD, MDA, and GSH could be effective biomarkers to evaluate the TAN oxidative stress, the maximum acceptable toxicant concentration (MATC) was 11.3 mg L^-1 for TAN. To our knowledge, this is the first study to propose biomarkers to evaluate potential environmental risk and establish a risk threshold for TAN in C. auratus.

A green recycling process of the spent lead paste from discarded lead-acid battery by a hydrometallurgical process

In this study, a green recycling process of discarded lead-acid battery paste, which could avoid both the smelting and electro-winning route has been developed. Leaching reagents containing sodium citrate, acetic acid and hydrogen peroxide were reacted with spent lead paste in aqueous media at the pH of 5-6. Lead paste was leached and formed into lead citrate precursor, which was recrystallized and separated from the solution. The optimal conditions for the leaching process at room temperature were found to be the: concentration of acetic acid solution of 0.92 mol L^-1; concentration of sodium citrate solution of 0.478 mol L^-1; initial mass ratio of solid spent lead paste to liquid (solid/liquid ratio) of 1/5 g/mL; and reaction time of 2 hours. The results showed that the desulphurization efficiency of lead paste was up to 99.9%. The optimal conditions for lead citrate re-crystallization from the leaching mixed solution were found to be the re-crystallization temperature of 55^oC for 5 hours in a water bath. The lead citrate precursor synthesized from discarded lead-acid battery pastes was the chemical formula of Pb₃(C₆H₅O₇)₂·3H₂O with columnar shape in the length of 30-50 μm, which was easily separated from the leaching solution. The results of kilogram-scale experiments made progress easier for obtaining the ultrafine lead oxide product (PbO and Pb) from discarded lead-acid battery paste.

The impact of socioeconomic system on the river system in a heavily disturbed basin

The quantitative assessment of the impact of socioeconomic development on river water environment is important to the scientific management of river basins. However, current methods have high data requirements or are difficult to deal with the impact between systems (which is defined by a collection of indicators). This paper first uses canonical correlation analysis (CCA) to understand the relationship between socialeconomic system (defined by a set of indicators reflecting socioeconomic development) and river system (defined by a set of indicators reflecting river water environment), and then proposes a method to assess the impact of socioeconomic system on river system by integrating CCA and the degrees of influence of river system indicators. The proposed method and framework are applied to the Shaying River Basin with the characteristics of multi-sluices, high pollution, and dense population based on data from 2000 to 2015. Results indicate that socioeconomic and river systems are highly related to each other with the average influence degree of greater than 0.9, indicating very close relationships between socioeconomic and river systems. The changes of influence degree vary between 0.19 and 0.79 with a turning point in 2010. Most of the influence levels are "moderate" (influence degree between 0.4 and 0.6) or "high" (influence degrees between 0.6 and 0.8) before 2010 but become to "low" (influence degrees between 0.2 and 0.4) since then. In addition, the influence degree shows a significant increase from upstream to downstream with Zhoukou Station as the turning point, meaning that the stronger the human activity is, the greater the impact of the socioeconomic system on the river system is. The main influential factors are population density and sewage treatment rate. The proposed method contributes to the research in river management with limited data availability and the results can serve as an important reference for basin management.

[Clinicopathologic analysis of extranodal non-hodgkin lymphoma of the sinonasal cavities: a 15-case report]

Objective:To investigate the clinical manifestation, imaging and histological features of different histological subtypes of non-Hodgkin's lymphoma of nasal cavity and paranasal sinuses.Method:Fifteen NHL patients of the sinonasal region were collected from the Department of Otolaryngology of Peking University Third Hospital from 2010 to 2016. HE staining and immunohistochemical staining were performed. The clinical characteristics and imaging features of different subtypes were described and analyzed.Result::We analyzed a total of 6 patients with localized sinonasal diffuse large B cell lymphoma and 9 patients with localized sinonasal extranodal NK/T cell lymphoma. The age distribution for these two subtypes is very distinct. The median age of the patients with localized sinonasal extranodal NK/T cell lymphoma was 39 years. There were 5 males and 4 females. Nine sinonasal NHLs were NK/T-cell lymphoma, nasal type, all of which were infected with EBV. The median age of the patients with localized sinonasal diffuse large B cell lymphoma was 64 years. There were 3males and 3 females. Symptoms for patients with SN-DLBCL and SN-ENKTL were significantly different in epiphora, proptosis, diplopia and nasal congestion (P=0.18, 0.004, 0.18, 0.18). Imaging features for patients with SN-DLBCL and SN-ENKTL were significantly different in tumor extended to orbit and inferior turbinate (P>0.05). Positive staining for CD 56 was detected in 9 patients, for CD 3 in 9 patients, for EBER in 9 patients. The Hans algorithm identified 1 patient with the germinal center B-cell (GCB) subtype and 5 with the non-GCB subtype.Compared with the control group, the observation group was significantly better than the control group (P < 0.01).Conclusion:Early symptoms of epiphora, proptosis, diplopia, and images finding with orbital invasion should be highly suspected of diffuse large B cell lymphoma. Positive staining for CD 56 and EBER were detected in all patients with extranodal NK/T cell lymphoma, and positive staining for CD20 was detected in all patients with SN-DLBCL.

A new framework for assessing river ecosystem health with consideration of human service demand

In order to study river health status from harmonic relationship between human and natural environment, a river health evaluation method was proposed from the aspects of ecosystem integrity and human service demand, and the understanding of river health connotation. The proposed method is based on the harmony theory and two types of river health assessment methods (the forecasting model and index evaluation). A new framework for assessing river water health was then formed from the perspective of harmony and dynamic evolution between human service demand and river ecosystem integrity. As a case study, the method and framework were applied to the Shaying River Basin, a tributary of the most polluted Huaihe River Basin in China. The health status of the river's ecosystem and its effect on the mainstream of Huaihe River were evaluated based on water ecological experiment. The results indicated that: (1) the water ecological environment in Shaying River was generally poor and showed a gradual changing pattern along the river. The river health levels were generally "medium" in the upstream but mostly "sub-disease" in the midstream and downstream, indicating that the water pollution in Shaying River were mainly concentrated in the midstream and downstream; (2) the water pollution of Shaying River had great influence on the ecosystem of Huaihe River, and the main influencing factors were TN, followed by TP and COD_Mn; (3) the natural attribute of river was transferring toward to the direction of socialization due to the increasing human activities. The stronger the human activity intervention is, the faster the transfer will be and the more river's attributes will match with human service demand. The proposed framework contributes to the research in water ecology and environment management, and the research results can serve as an important reference for basin management in Shaying River and Huaihe River.

A new method for water quality assessment: by harmony degree equation

Water quality assessment is an important basic work in the development, utilization, management, and protection of water resources, and also a prerequisite for water safety. In this paper, the harmony degree equation (HDE) was introduced into the research of water quality assessment, and a new method for water quality assessment was proposed according to the HDE: by harmony degree equation (WQA-HDE). First of all, the calculation steps and ideas of this method were described in detail, and then, this method with some other important methods of water quality assessment (single factor assessment method, mean-type comprehensive index assessment method, and multi-level gray correlation assessment method) were used to assess the water quality of the Shaying River (the largest tributary of the Huaihe in China). For this purpose, 2 years (2013-2014) dataset of nine water quality variables covering seven monitoring sites, and approximately 189 observations were used to compare and analyze the characteristics and advantages of the new method. The results showed that the calculation steps of WQA-HDE are similar to the comprehensive assessment method, and WQA-HDE is more operational comparing with the results of other water quality assessment methods. In addition, this new method shows good flexibility by setting the judgment criteria value HD₀ of water quality; when HD₀ = 0.8, the results are closer to reality, and more realistic and reliable. Particularly, when HD₀ = 1, the results of WQA-HDE are consistent with the single factor assessment method, both methods are subject to the most stringent "one vote veto" judgment condition. So, WQA-HDE is a composite method that combines the single factor assessment and comprehensive assessment. This research not only broadens the research field of theoretical method system of harmony theory but also promotes the unity of water quality assessment method and can be used for reference in other comprehensive assessment.

[Clinically predictive factors of Gleason score upgrading in patients after radical prostatectomy]

OBJECTIVE

To assess the discrepancy between preoperative needle biopsy (NB) Gleason score and pathological specimen Gleason score (GS) after radical prostatectomy, and to explore the risk factors of postoperative upgrading of GS.

METHODS

We retrospectively evaluated 160 patients who suffered from biopsy proved prostatic carcinoma and performed radical prostatectomy. Age of the patients was 57-82 years, with the average age of 71.6; prebiopsy prostate specific antigen (PSA) was 0.31-40.32 μg/L,with the average PSA of 11.29 μg/L; body mass index (BMI) was 16.41-32.04 kg/m², with the average BMI of 23.63 kg/m²; prostate volume (PV) was 9.52-148.46 mL, with the average PV of 40.19 mL. All the patients included in the study had complete information for clinical variables, including age, BMI, prebiopsy PSA level, PV, number of biopsy cores obtained, percentage, clinical stage, and biopsy GS. Grading of NB Gleason score was compared with their corresponding radical prostatectomy specimens, and the discrepancy between the NB and prostatectomy specimens GS assessed. Upgrading was defined as any increase in the pathological GS over that of the biopsy GS as a total sum of primary and secondary grades or a change in the order of primary and secondary grades towards higher ones. Univariable and multivariable Logistic regression analyses were used to identify predictors of pathological grading changes.

RESULTS

Of the 160 patients, the specimen GS was upgraded in 49 (30.6%) patients and remained with no change in 82 (51.3%) patients. Univariate and multivariate regression analysis showed that prostate volume and biopsy GS were independent predictors with postoperative upgrading of GS. Age, BMI, PSA before needle biopsy, clinical stage and needle number showed no statistical significance (P>0.05).

CONCLUSION

Lower biopsy GS and smaller prostate volume are increased risks for clinically upgrading of GS after radical prostatectomy. This fact should be kept in mind when deciding on therapy decisions for patients with prostate cancer.

[Clinically predictive factors of Gleason score upgrading in patients after radical prostatectomy]

OBJECTIVE

To assess the discrepancy between preoperative needle biopsy (NB) Gleason score and pathological specimen Gleason score (GS) after radical prostatectomy, and to explore the risk factors of postoperative upgrading of GS.

METHODS

We retrospectively evaluated 160 patients who suffered from biopsy proved prostatic carcinoma and performed radical prostatectomy. Age of the patients was 57-82 years, with the average age of 71.6; prebiopsy prostate specific antigen (PSA) was 0.31-40.32 μg/L,with the average PSA of 11.29 μg/L; body mass index (BMI) was 16.41-32.04 kg/m(2), with the average BMI of 23.63 kg/m(2); prostate volume (PV) was 9.52-148.46 mL, with the average PV of 40.19 mL. All the patients included in the study had complete information for clinical variables, including age, BMI, prebiopsy PSA level, PV, number of biopsy cores obtained, percentage, clinical stage, and biopsy GS. Grading of NB Gleason score was compared with their corresponding radical prostatectomy specimens, and the discrepancy between the NB and prostatectomy specimens GS assessed. Upgrading was defined as any increase in the pathological GS over that of the biopsy GS as a total sum of primary and secondary grades or a change in the order of primary and secondary grades towards higher ones. Univariable and multivariable Logistic regression analyses were used to identify predictors of pathological grading changes.

RESULTS

Of the 160 patients, the specimen GS was upgraded in 49 (30.6%) patients and remained with no change in 82 (51.3%) patients. Univariate and multivariate regression analysis showed that prostate volume and biopsy GS were independent predictors with postoperative upgrading of GS. Age, BMI, PSA before needle biopsy, clinical stage and needle number showed no statistical significance (P>0.05).

CONCLUSION

Lower biopsy GS and smaller prostate volume are increased risks for clinically upgrading of GS after radical prostatectomy. This fact should be kept in mind when deciding on therapy decisions for patients with prostate cancer.

Identification of key factors affecting the water pollutant concentration in the sluice-controlled river reaches of the Shaying River in China via statistical analysis methods

The construction of sluices creates a strong disturbance in water environmental factors within a river. The change in water pollutant concentrations of sluice-controlled river reaches (SCRRs) is more complex than that of natural river segments. To determine the key factors affecting water pollutant concentration changes in SCRRs, river reaches near the Huaidian Sluice in the Shaying River of China were selected as a case study, and water quality monitoring experiments based on different regulating modes were implemented in 2009 and 2010. To identify the key factors affecting the change rates for the chemical oxygen demand of permanganate (CODMn) and ammonia nitrogen (NH3-N) concentrations in the SCRRs of the Huaidian Sluice, partial correlation analysis, principal component analysis and principal factor analysis were used. The results indicate four factors, i.e., the inflow quantity from upper reaches, opening size of sluice gates, water pollutant concentration from upper reaches, and turbidity before the sluice, which are the common key factors for the CODMn and NH3-N concentration change rates. Moreover, the dissolved oxygen before a sluice is a key factor for the permanganate concentration from CODMn change rate, and the water depth before a sluice is a key factor for the NH3-N concentration change rate. Multiple linear regressions between the water pollutant concentration change rate and key factors were established via multiple linear regression analyses, and the quantitative relationship between the CODMn and NH3-N concentration change rates and key affecting factors was analyzed. Finally, the mechanism of action for the key factors affecting the water pollutant concentration changes was analyzed. The results reveal that the inflow quantity from upper reaches, opening size of sluice gates, permanganate concentration from CODMn from upper reaches and dissolved oxygen before the sluice have a negative influence and the turbidity before the sluice has a positive influence on the permanganate concentration from CODMn change rates and that the opening size of sluice gates, NH3-N concentration from upper reaches, and water depth before the sluice have a negative influence and the inflow quantity from upper reaches and turbidity before the sluice have a positive influence on the NH3-N concentration change rates, which provides a scientific grounding for pollution control and sluice operations in SCRRs.

Experimental analysis of the impact of sluice regulation on water quality in the highly polluted Huai River Basin, China

Impact assessment of sluice regulation on water quality is one of the crucial tasks in the present river management. However, research difficulties remain because of insufficient in situ data and numerous influencing factors in aquatic environments. The Huaidian Sluice, the main control sluice of the Shaying River, China, was selected for this study. Three field experimental programs were designed and carried out to analyze spatial and temporal variations in water quality parameters under various sluice regulation conditions and to explore the impacts of regulation mechanisms on water quality. Monitoring data were used to simulate water quality under different scenarios by the water quality analysis simulation program (WASP). Results demonstrate that the influences of sluice regulation on permanganate index (CODMn) and ammonia nitrogen (NH4-N) concentrations (indicators of water quality) were complex and nonlinear and presented different trends of increase or decrease from different regulation modes. Gate openings of different widths and different flow rates affected CODMn and NH4-N concentrations differently. Monitoring results and numerical simulation results indicate that the sluice opening should be small. Flow discharge through the sluice should be greater than 10 m(3) s and less than 60 m(3) s to maintain low CODMn concentrations, and discharge should be low (e.g., 14 m(3) s) to maintain low NH4-N concentrations. This research provides an experimental basis for further research on the construction of water quality models and for the development of reasonable regulations on water quality and quantity.

The Changes of Muscle FGF-6 Expression at Different Time Points after Exercise-induced Muscle Damage

OBJECTIVE

To investigate the changes of fibroblast growth factor (FGF)-6 expression in the regeneration and repair process after exercise-induced muscle damage (EIMD) and the relationship with skeletal muscle regeneration and repair.

METHODS

The expression of FGF-6 at different time points was examined by reverse transcription-polymerase chain reaction (PCR) and immunohistochemistry staining after a downhill treadmill exercise. Skeletal muscle injury and regeneration at different times after EIMD was assessed by haematoxylin and eosin (H and E) staining.

RESULTS

The FGF-6 protein expression was initially elevated and followed by a gradual reduction, while the changes of FGF-6 mRNA were almost all raised after the treadmill exercise.

CONCLUSION

The results point out that FGF-6 is closely related to skeletal muscle regeneration and repair, probably implying a dual function in muscle regeneration.

Influence of changes in hydrodynamic conditions on cadmium transport in tidal river network of the Pearl River Delta, China

With rapid economic development, the Pearl River Delta (PRD) of China has experienced a series of serious heavy metal pollution events. Considering complex hydrodynamic and pollutants transport process, one-dimensional hydrodynamic model and heavy metal transport model were developed for tidal river network of the PRD. Then, several pollution emergency scenarios were designed by combining with the upper inflow, water quality and the lower tide level boundary conditions. Using this set of models, the temporal and spatial change process of cadmium (Cd) concentration was simulated. The influence of change in hydrodynamic conditions on Cd transport in tidal river network was assessed, and its transport laws were summarized. The result showed the following: Flow changes in the tidal river network were influenced remarkably by tidal backwater action, which further influenced the transport process of heavy metals; Cd concentrations in most sections while encountering high tide were far greater than those while encountering middle or low tides; and increased inflows from upper reaches could intensify water pollution in the West River (while encountering high tide) or the North River (while encountering middle or low tides).

[Influence of phthalates from Shaying river on children's intelligence and secretion of thyroid hormone]

OBJECTIVE

To investigate the effect of phthalates exposure from drinking water on children's intelligence and secretion of thyroid hormone.

METHODS

Two villages in S County were selected randomly as polluted area and control area according to the distance from the Shaying river basin. Phthalates including DEP, DBP, DMP, DEHP were measured both in the river water and drinking water using HPLC method. Children aged 8 to 13 years old studying in the village primary school were recruited by cluster sampling (n = 154). The combined Reven Test was used to test children intelligence and ELISA method was used to determined thyroid hormone levels.

RESULTS

The concentrations of phthalates (DEP, DBP) were exceeding standards of surface water quality in any of the three sections of the river. Compared to the control area, the concentration of DEP and DBP in drinking water were significant higher in the polluted area than that in control area (P < 0.05). Children from polluted area had significant higher FT4 concentration compared to children from control area (P < 0.05). Intelligence level in children from polluted area was lower than that from control area (P < 0.05).

CONCLUSION

The drinking water has been polluted by Shaying river and thyroid hormones levels of children were affected in the polluted areas. It is necessary to verify if this change is related to the phthalates.

Uptake of polycyclic aromatic hydrocarbons by maize plants

Roots and above-ground parts (tops) of maize plants, comprising cuticles, leaves and stems, have been exposed separately to polycyclic aromatic hydrocarbons (PAHs) by means of air-tight bicameral exposure devices. Maize roots and tops of plants directly accumulate PAHs from aqueous solutions and from air in proportion to exposure levels. Root and leaf concentration factors (log RCF and log LCF) are log-linear functions of log-based octanol-water partition coefficient (log Kow) and log-based octanol-air partition coefficient (log Koa). The PAHs' concentrations among cuticles, leaves and stems display good correlations with each other. PAH concentrations in each part of the plant tested correlated positively with atmospheric PAHs' concentrations. Comparisons between PAHs' concentrations of root epidermis and root tissue showed similar correlations. Bulk concentrations of contaminants in various plant tissues differed greatly, but these differences disappeared after normalization to lipid contents suggesting lipid-based partitioning of PAHs among maize tissues.

Source apportionment of polycyclic aromatic hydrocarbons in surface soil in Tianjin, China

Principal component analysis and multiple linear regression were applied to apportion sources of polycyclic aromatic hydrocarbons (PAHs) in surface soils of Tianjin, China based on the measured PAH concentrations of 188 surface soil samples. Four principal components were identified representing coal combustion, petroleum, coke oven plus biomass burning, and chemical industry discharge, respectively. The contributions of major sources were quantified as 41% from coal, 20% from petroleum, and 39% from coking and biomass, which are compatible with PAH emissions estimated based on fuel consumption and emission factors. When the study area was divided into three zones with distinctive differences in soil PAH concentration and profile, different source features were unveiled. For the industrialized Tanggu-Hangu zone, the major contributors were cooking (43%), coal (37%) and vehicle exhaust (20%). In rural area, however, in addition to the three main sources, biomass burning was also important (13%). In urban-suburban zone, incineration accounted for one fourth of the total.

A two-compartment exposure device for foliar uptake study

An airtight two-chamber exposure devise was designed for investigating foliar uptake of polycyclic aromatic hydrocarbons (PAHs) by plants. The upper and the bottom chambers of the device were air-tightly separated by an aluminum foil and the plant aerial tissues and roots were exposed in the two chambers, respectively. The device was tested using maize exposed to several PAH species. Positive correlations between air and aerial tissue concentrations of the exposed PAH species were revealed. PAHs spiking in the culture solution had no influence on the leaf concentrations.

Source diagnostics of polycyclic aromatic hydrocarbons based on species ratios: a multimedia approach

Often, the sources of polycyclic aromatic hydrocarbons (PAHs) in environmental media can be identified by comparing the ratios of concentrations of selected pairs of PAH congeners in the source emissions to the ratios in the contaminated environmental media. However, these ratios can be altered significantly due to differences in the transport of the PAH compounds in a multimedia environment. To examine such changes, a fugacity model was applied to PAH ratios in a model environment. A linear relationship between the rate of emission and the bulk media concentration was identified for each PAH compound in an environmental medium at steady state and was quantified by a receptor-to-source ratio (RRS). It was demonstrated that the RRS values of the two congeners usually differ significantly. Consequentially, PAH ratios changed remarkably from the source emissions to various environmental media. A site-specific rectification factor (RF) was defined as the ratio of the two RRS values of the paired congeners for a specific PAH ratio in a given medium, which can be applied to account for the ratio changes in a multimedia environment. The PAH ratio changes were further verified with the surface soil data collected from Tianjin, China, and the observed changes of PAH ratios were compared favorably with the model predictions. The sensitivity analysis revealed that PAH ratios of the low molecular weight compounds were less stable. The most influential parameters controlling PAH ratios were those pertaining to dry precipitation, surface-to-air diffusion, degradation in air and water, and exchange between water and sediment.

Human exposure and health risk of alpha-, beta-, gamma- and delta-hexachlorocyclohexane (HCHs) in Tianjin, China

The dynamic exposures to HCHs of individuals born between the years 1913 and 1993 in Tianjin have been simulated by connecting a fugacity model (IV) with a multimedia exposure model. Ingestion is the most important pathway for human beings to take up HCHs, and concentrations in the human body correlate with body weight changes. Accumulations of HCHs were derived assuming that the degradation in human body behaved linearly. The health risk of exposure to HCHs was measured using cancer risk and loss of life expectancy (LLE), and LLE was modified from its original definition to incorporate a dynamic calculation that takes variances in exposure into account. Monte-Carlo simulations were run to analyze the uncertainties of the model.

Contamination of rivers in Tianjin, China by polycyclic aromatic hydrocarbons

Tianjin urban/industrial complex is highly polluted by some persistent organic pollutants. In this study, the levels of 16 priority polycyclic aromatic hydrocarbons (PAHs) were tested in sediment, water, and suspended particulate matter (SPM) samples in 10 rivers in Tianjin. The total concentration of 16 PAHs varied from 0.787 to 1943 microg/g dry weight in sediment, from 45.81 to 1272 ng/L in water, and from 0.938 to 64.2 microg/g dry weight in SPM. The levels of PAHs in these media are high in comparison with values reported from other river and marine systems. Variability of total concentrations of PAHs in sediment, water, and SPM from nine different rivers is consistent with each other. No obvious trends of total PAHs concentration variations were found between upstream and downstream sediment, water, and SPM samples for most rivers, which indicate local inputs and disturbances along these rivers. The spatial distributions of three-phase PAHs are very similar to each other, and they are also similar to those found in topsoil. However, their chemical profiles are significantly different from that of topsoil. The change of profiles is consistent with the different aqueous transport capability of 16 PAHs. Low molecular weight PAHs predomination suggests a relatively recent local source and coal combustion source of PAHs in the study area.

Inhibition of myogenesis by depletion of the glycogen-associated regulatory subunit of protein phosphatase-1 in rat skeletal muscle cells

In this study, we examined the role of the glycogen-associated regulatory subunit of protein phosphatase-1 (PP-1(G)) in L6 rat skeletal muscle cell myogenesis. The level of PP-1(G) was depleted by transfection with an inducible antisense-oriented PP-1(G) gene. Western blot analysis of the PP-1(G)-depleted cell line revealed a >90% depletion of PP-1(G) protein and a 45% reduction in cellular PP-1 activity and abolished the ability of L6 myoblasts to differentiate into multinucleated myotubes. PP-1(G)-depleted cells also exhibited a marked reduction in the expression of the differentiation marker myogenin as well as creatine kinase. After 7 days in culture, PP-1(G)-depleted cells sustained myoblast levels of inhibitor of differentiation-2, whereas control L6 cells had a severely lower inhibitor of differentiation-2 level and progressed into myotubes. Myoblasts were unable to exit the cell cycle, as measured by the impaired induction of p27 cyclin-dependent kinase inhibitor, a >2-fold increase in DNA synthesis, and elevated levels of phosphorylated retinoblastoma protein (pRb). Replacement of the PP-1(G) gene restored PP-1(G) protein expression, PP-1 enzymatic activity, and the ability to differentiate into myotubes. We conclude that PP-1(G) plays a definite role in L6 myogenesis via its regulation of PP-1 catalytic activity.

[A case-control study on Guillain-Barre syndrome in children of North China]

OBJECTIVE

This study aimed at exploring the risk factors for Guillain-Barre syndrome (GBS).

METHODS

A case-control study design was used with 51 cases of GBS, diagnosed based on their symptoms, signs and electrophysiological examinations and exclusion of poliomyelitis and other acute flaccid paralysis, and 51 controls matched on age, sex and resident village. Serum IgG antibodies specific for Campylobacter jejuni were determined for all the subjects by enzyme-linked immunosorbent assay (ELISA) with a preparation of surface antigen of C. jejuni C(1) strain isolated from the patients and prevalent in north China. Each case and control were interviewed with his/her parents or guardians by a trained interviewer using an ad hoc questionnaire, including his/her demographic information, socioeconomic status, onset of the illness, and potential risk factors in their environment and personal hygiene. Data were analyzed with SAS software release 6.04 in a microcomputer.

RESULTS

GBS was associated with a few factors, such as residential areas (45 of the 51 cases living in the rural areas, accounting for 88.2% of the total), polio and hepatitis B vaccine immunization before onset of the illness (with ORs of 7.27 and 3.14, respectively), no hand washing after defecation and before meals (with an OR of 6.15) and getting cold and going to the river or lake site before onset of the illness (with ORs of 13.75 and 12.20, respectively). Infection with Campylobacter jejuni associated strongly with the illness (with an OR of 9.5, P < 0.001). Thirty-five of the 51 cases had precursor symptoms before onset of the illness (68.6%).

CONCLUSION

It suggests that occurrence of GBS may correlate to infection with Campylobacter jejuni and poor personal hygiene in children.

Effect of calcitonin on calcium transport by the luminal and basolateral membranes of the rabbit nephron

In the rabbit, calcitonin has been shown to enhance calcium (Ca2+) reabsorption in the early distal tubule. The aim of the present study was to investigate the mechanism of this action, using isolated luminal and basolateral membranes of distal tubules. The tubule suspensions were preincubated in the presence or absence of 10(-7) M calcitonin. The luminal or basolateral membranes were subsequently purified and 45Ca transport through the vesicles was measured using the rapid filtration technique. Results were compared with those obtained from proximal tubule membranes. In the proximal tubules, calcitonin had no effect on Ca2+ uptake by luminal membranes. In the distal tubules, the presence of Na+ in the incubation medium strongly decreased the uptake of Ca2+ by luminal membranes. Preincubation of distal tubules with calcitonin partially restored this uptake. We previously reported a dual kinetics of Ca2+ uptake by the distal luminal membranes. Calcitonin enhanced Ca2+ transport by the low affinity component, increasing the Vmax and leaving the K(m) unchanged. Renal calcitonin receptors usually couple to both adenylate cyclase and phospholipase C. To determine through which messenger(s) calcitonin enhances Ca2+ transport by the distal tubules, we first confirmed that the hormone stimulates cAMP and IP3 release. Incubation of the distal tubules with 10(-7) M calcitonin significantly increased both messengers. In contrast, calcitonin did not influence the IP3 nor the cAMP content of proximal tubules. Therefore, we studied the actions of cAMP and phorbol 12-myristate 13 acetate (PMA) on Ca2+ transport by the distal luminal membranes. Incubation of distal tubule suspensions with dibutyryl cAMP significantly increased Ca2+ uptake by the luminal membranes. However, incubation of these tubules with various concentrations of PMA (10 nM, 100 nM and 1 microM) had no effect on this uptake. Calcitonin also influenced Ca2+ transport by the distal basolateral membrane. Incubation of distal tubule suspensions with 10(-7) M calcitonin activated the Na+/Ca2+ exchanger activity, almost doubling the Na+ dependent Ca2+ uptake. Here again this action was mimicked by cAMP. We conclude that calcitonin increases Ca2+ transport by the distal tubule through two mechanisms: the opening of low affinity Ca2+ channels in the luminal membrane and the stimulation of the Na+/Ca2+ exchanger in the basolateral membrane, both actions depending on the activation of adenylate cyclase.

[Chemical constituents of seeds of Camellia sinensis var. assamica]

Five compounds were isolated from the acid-hydrolytic products of n-butanol extract and ethanol extract of the seeds of Camellia sinensis var. assamica. Their structures were elucidated by chemical and spectroscopic analyses as octacosane, three new acyl-sapogenins: 22-O-angeloyl theasapogenol B, 22-O-angeloyl theasapogenol E and 22-O-angeloyl theasapogenol A, and naringenin respectively.