A comprehensive analysis of submarine groundwater discharge and nutrient fluxes in the Bohai Sea, China

Groundwater discharge and associated nutrient fluxes in the Bohai Sea, China has attracted great attention, but most studies lacked high spatial resolution for the whole sea. As the largest semi-enclosed sea in China, the Bohai Sea is confronted with strong environmental pollution problems such as eutrophication induced by terrestrial nutrient inputs. However, the role of SGD has not been evaluated well for the whole Bohai Sea. In this study, stable isotopes (hydrogen and oxygen), radioactive isotope (228Ra), salinity, and temperature were combined to trace the diluted seawater. Mass balances of 228Ra, oxygen isotope, and salinity were used to quantify SGD and nutrient fluxes to the Bohai Sea. The estimated submarine fresh groundwater discharge (SFGD) and SGD to the Bohai Sea were (6.0 ± 0.5) × 109 and (2.7 ± 1.6) × 1011 m3 a-1, respectively. SFGD represents 10 % to 11 % of the total river discharge and SGD is about 2 to 8 folds of the total river discharge to the sea. Moreover, SGD derived dissolved nutrients to the Bohai Sea were (4.8 ± 4.0) × 1010 mol a-1 for dissolved inorganic nitrogen, (1.9 ± 1.7) × 1010 mol a-1 for dissolved inorganic phosphorus, and (6.7 ± 5.5) × 1010 mol a-1 for silicon. These nutrient inputs were about 10 to 20 folds of the total riverine inputs. Overall, this study underscores the importance of evaluating SGD to better understand the terrestrial imported nutrients in regional scale.

The changing nature of groundwater in the global water cycle

In recent decades, climate change and other anthropogenic activities have substantially affected groundwater systems worldwide. These impacts include changes in groundwater recharge, discharge, flow, storage, and distribution. Climate-induced shifts are evident in altered recharge rates, greater groundwater contribution to streamflow in glacierized catchments, and enhanced groundwater flow in permafrost areas. Direct anthropogenic changes include groundwater withdrawal and injection, regional flow regime modification, water table and storage alterations, and redistribution of embedded groundwater in foods globally. Notably, groundwater extraction contributes to sea level rise, increasing the risk of groundwater inundation in coastal areas. The role of groundwater in the global water cycle is becoming more dynamic and complex. Quantifying these changes is essential to ensure sustainable supply of fresh groundwater resources for people and ecosystems.

Long-term gridded land evapotranspiration reconstruction using Deep Forest with high generalizability

Previous datasets have limitations in generalizing evapotranspiration (ET) across various land cover types due to the scarcity and spatial heterogeneity of observations, along with the incomplete understanding of underlying physical mechanisms as a deeper contributing factor. To fill in these gaps, here we developed a global Highly Generalized Land (HG-Land) ET dataset at 0.5° spatial resolution with monthly values covering the satellite era (1982-2018). Our approach leverages the power of a Deep Forest machine-learning algorithm, which ensures good generalizability and mitigates overfitting by minimizing hyper-parameterization. Model explanations are further provided to enhance model transparency and gain new insights into the ET process. Validation conducted at both the site and basin scales attests to the dataset's satisfactory accuracy, with a pronounced emphasis on the Northern Hemisphere. Furthermore, we find that the primary driver of ET predictions varies across different climatic regions. Overall, the HG-Land ET, underpinned by the interpretability of the machine-learning model, emerges as a validated and generalized resource catering to scientific research and various applications.

Uncovering the processes of microbial community assembly in the near-surface sediments of a climate-sensitive glacier-fed lake

Glacier-fed lakes are characterized by cold temperatures, high altitudes, and nutrient-poor conditions. Despite these challenging conditions, near-surface sediments of glacier-fed lakes harbor rich microbial communities that are critical for ecosystem functioning and serve as a bridge between aquatic ecology and the deep subsurface biosphere. However, there is limited knowledge regarding the microbial communities and their assembly processes in these sediments, which are highly vulnerable to climate change. To fill this knowledge gap, this study systematically analyzed environmental variables, microbial communities, diversity, co-occurrence relationships, and community assembly processes in the near-surface sediments of a glacier-fed lake in the Tibetan Plateau. The results revealed distinct vertical gradients in microbial diversity and subcommunities, highlighting the significant influence of selection processes and adaptive abilities on microbial communities. Specifically, specialists played a crucial role within the overall microbial communities. Microbial assembly was primarily driven by homogeneous selection, but its influence declined with increasing depth. In contrast, homogenizing dispersal showed an opposite pattern, and the bottom layer exhibited heterogeneous selection and undominated processes. These patterns of microbial assembly were primarily driven by environmental gradients, with significant contributions from processes associated to ammonium and organic matter deposition, as well as chemical precipitation in response to a warming climate. This study enhances our understanding of the microbial communities and assembly processes in the near-surface sediments of glacier-fed lakes and sheds light on geo-microbiological processes in climate-sensitive lacustrine sediments.

A new model to predict soil thermal conductivity

Thermal conductivity is a basic parameter of soil heat transferring, playing an important role in many fields including groundwater withdrawal, ground source heat pump, and heat storage in soils. However, it usually requires a lot of time and efforts to obtain soil thermal conductivity. To conveniently obtain accurate soil thermal conductivity, a new model describes the relationship between soil thermal conductivity (λ) and degree of saturation (S_r) was proposed in this study. Dry soil thermal conductivity (λ_dry) and saturated soil thermal conductivity (λ_sat) were described using a linear expression and a geometric mean model, respectively. A quadratic function with one constant was added to calculate λ beyond the lower λ_dry and upper λ_sat limit conditions. The proposed model is compared with five other frequently used models and measured data for 51 soil samples ranging from sand to silty clay loam. Results show that the proposed model match the measured data well. The proposed model can be used to determine soil thermal conductivity of a variety of soil textures over a wide range of water content.

[Clinical and genetic characteristics of young patients with myeloproliferative neoplasms]

Objectives: To investigate the clinical and genetic features of young Chinese patients with myeloproliferative neoplasms (MPN). Methods: In this cross-sectional study, anonymous questionnaires were distributed to patients with MPN patients nationwide. The respondents were divided into 3 groups based on their age at diagnosis: young (≤40 years) , middle-aged (41-60 years) , and elderly (>60 years) . We compared the clinical and genetic characteristics of three groups of MPN patients. Results: 1727 assessable questionnaires were collected. There were 453 (26.2%) young respondents with MPNs, including 274 with essential thrombocythemia (ET) , 80 with polycythemia vera (PV) , and 99 with myelofibrosis. Among the young group, 178 (39.3%) were male, and the median age was 31 (18-40) years. In comparison to middle-aged and elderly respondents, young respondents with MPN were more likely to present with a higher proportion of unmarried status (all P<0.001) , a higher education level (all P<0.001) , less comorbidity (ies) , fewer medications (all P<0.001) , and low-risk stratification (all P<0.001) . Younger respondents experienced headache (ET, P<0.001; PV, P=0.007; MF, P=0.001) at diagnosis, had splenomegaly at diagnosis (PV, P<0.001) , and survey (ET, P=0.052; PV, P=0.063) . Younger respondents had fewer thrombotic events at diagnosis (ET, P<0.001; PV, P=0.011) and during the survey (ET, P<0.001; PV, P=0.003) . JAK2 mutations were found in fewer young people (ET, P<0.001; PV, P<0.001; MF, P=0.013) ; however, CALR mutations were found in more young people (ET, P<0.001; MF, P=0.015) . Furthermore, mutations in non-driver genes (ET, P=0.042; PV, P=0.043; MF, P=0.004) and high-molecular risk mutations (ET, P=0.024; PV, P=0.023; MF, P=0.001) were found in fewer young respondents. Conclusion: Compared with middle-aged and elderly patients, young patients with MPN had unique clinical and genetic characteristics.

Сyclooxygenase-2 Inhibitor Parecoxib Reduces LPS-Induced Activation of BV2 Microglia Cells

We studied the inhibitory effect of cyclooxygenase-2 inhibitor parecoxib on LPS-induced activation of BV2 microglia cells. The optimal dose of parecoxib (80 μmol/liter) was evaluated by the Cell Counting Kit-8. The cells were divided into the following groups: control (intact cells without treatment); LPS (treatment with 1 μg/ml LPS for 6 h), and experimental (pretreatment with 80 μmol/liter parecoxib for 24 h followed by incubation with 1 μg/ml LPS for 6 h). Cell morphology and proliferation and the expression of NLRP3, caspase-1, pro-caspase-1, and IL-1β were assessed. LPS induced significant morphological changes and decreased proliferation of primary BV2 cells in comparison with the control. These changes were prevented by parecoxib pretreatment. LPS significantly increased NLRP3 inflammatory vesicle activation and expression of NLRP3, caspase-1, pro-caspase-1, and IL-1β in comparison with the control group; pretreatment with parecoxib prevented all these changes. Our results suggest that pretreatment with parecoxib inhibited LPS-induced activation of BV2 microglial cells and probably inhibited NLRP3 inflammasome activation.

Subglacial Meltwater Recharge in the Dongkemadi River Basin, Yangtze River Source Region

Glaciers on the Tibetan Plateau play an important role in the local hydrological cycle. However, there are only few studies on groundwater in the alpine basins in the Tibetan Plateau which considered the effects of glaciers. Glaciers are extensively distributed in the Dongkemadi River Basin, which is a representative alpine basin in the Yangtze River source region. This study focuses on building a numerical groundwater flow model with glaciations using HydroGeoSphere (HGS) to simulate subglacial meltwater recharge to groundwater in the Dongkemadi River Basin in response to future climate changes. Effects of hydraulic conductivity, precipitation, and temperature on subglacial meltwater recharge to groundwater were discussed. Glacier changes in the future 50 years were predicted under different climate change scenarios. Results show that: (1) the average thickness of the glacier will change significantly; (2) the simulated rate of annual mean subglacial meltwater recharge to groundwater is 4.58 mm, which accounts for 6.33% of total groundwater recharge; and (3) hydraulic conductivity has the largest influence on subglacial meltwater recharge to groundwater, followed by temperature and precipitation. Results of this study are also important to sustainable water resource usage in the Yangtze River source region.

Water quality and health risk assessment of the water bodies in the Yamdrok-tso basin, southern Tibetan Plateau

Water resources in good quality guarantee the primary condition for the maintenance and development of the natural ecosystem and human society. Water quality status and health risk of the lake water bodies in the national nature reserve, the Yamdrok-tso basin, in the southern Tibetan Plateau are assessed by 25 water parameters including 12 heavy metal(loid)s. Results reveal that the lake water bodies possess relatively high pH (9.68), high concentrations of F (1.66 mg/L), Cu (13.92 μg/L), As (41.60 μg/L), Pb (26.69 μg/L), and U (19.53 μg/L), and a low value of dissolved oxygen (19.30%). The pollution indices (heavy metal pollution index of 0.88-22.88, heavy metal evaluation index of 0.18-3.75, and the degree of contamination of -8.82 to -5.25) demonstrate that the lake water bodies are in a low pollution level with respect to heavy metal(loid)s. The evaluation of water quality based on the fuzzy comprehensive assessment method suggests that 75.56% of the water samples meet the regulation of the China National Standard for water resources in national nature reserves. Health risk assessment shows that potential hazards exist on this region when the residents under long-term exposure to the lake water through oral and dermal pathways, of which children and adults are mostly exposed to As and F for non-carcinogenic and As for carcinogenic risks, especially for children. Results of this study contribute to targeted water resources management in the national nature reserves.

Environmental emission, fate and transformation of microplastics in biotic and abiotic compartments: Global status, recent advances and future perspectives

The intensive use and wide-ranging application of plastic- and plastic-derived products have resulted in alarming levels of plastic pollution in different environmental compartments worldwide. As a result of various biogeochemical mechanisms, this plastic litter is converted into small, ubiquitous and persistent fragments called microplastics (<5 mm), which are of significant and increasing concern to the scientific community. Microplastics have spread across the globe and now exist in virtually all environmental compartments (the soil, atmosphere, and water). Although these compartments are often considered to be independent environments, in reality, they are very closely linked. Ample research has been done on microplastics, but there are still questions and knowledge gaps regarding the emission, occurrence, distribution, detection, environmental fate and transport of MPs in different environmental compartments. The current article is intended to provide a systematic overview of MP emissions, pollution conditions, sampling and analytical approaches, transport, fates and transformation mechanisms in different environmental compartments. It also identifies research gaps and future research directions and perspectives.

Health impacts of indoor air pollution from household solid fuel on children and women

The inefficient and incomplete combustion of solid fuel (SF) is associated with high levels of indoor air pollutants leading to 3.55 million deaths annually. The risk is higher in women and children, due to their higher exposure duration and unique physical properties. The current article aims to provide a critical overview regarding the use of solid fuel, its associated pollutants, their toxicity mechanisms and, most importantly the associated health impacts, especially in women and children. Pollutants associated with SF mostly include polycyclic aromatic hydrocarbons, particulate matter, nitrous oxide, carbon monoxide and sulfur dioxide, and their concentrations are two- to threefold higher in indoor environments. These pollutants can lead to a variety of health risks by inducing different toxicity mechanisms, such as oxidative stress, DNA methylation, and gene activation. Exposed children have an increased prevalence of low birth weight, acute lower respiratory tract infections, anemia and premature mortality. On the other hand, lung cancer, chronic obstructive pulmonary disease and cardiovascular diseases are the major causes of disability and premature death in women. Indoor air pollution resulting from SF combustion is a major public health threat globally. To reduce the risks, it is important to identify future research gaps and implement effective interventions and policies.

Life stages and morphological variations of Limnocythere inopinata (Crustacea, Ostracoda) from Lake Jiang-Co (northern Tibet): a bioculture experiment

Limnocythereinopinata (Baird, 1843) is a Holarctic species, abundant in a number of Recent and fossil ostracod assemblages, and has many important taxonomic and (paleo)ecological applications. However, the life cycle and morphological characteristics of the living L.inopinata are still unclear. A bioculture experiment was designed to study life stages and morphological variations from stage A-8 to adult in this species. The living animals were collected from Lake Jiang-Co, in the northern Tibetan Plateau. Results reveal that this species possesses a special growth pattern with the maximum size increase occurring at the transition from the instars A-5 to A-4. The growth pattern deviates from Brooks’ rule and one population from Lake Dali, eastern Mongolian Plateau. This suggests that the life history of L.inopinata may be influenced by environmental factors. Some morphological differences between Lake Jiang-Co and European populations of L.inopinata are also uncovered. Therefore, a detailed morphological description of this population is provided, but refrain from erecting a new species at the present stage because those differences appear to be inconsistent.

Localization and characterization of a putative cysteine desulfurase in Chlamydia psittaci

Chlamydia psittaci is an obligate intracellular pathogen with a biphasic developmental life cycle. It is auxotrophic for a variety of essential metabolites and obtains amino acids from eukaryotic host cells. Chlamydia can develop inside host cells within chlamydial inclusions. A pathway secreting proteins from inclusions into the host cellular cytoplasm is the type III secretion system (T3SS). The T3SS is universal among several Gram-negative bacteria. Here, we show that CPSIT_0959 of C. psittaci is expressed midcycle and secreted into the infected cellular cytoplasm via the T3SS. Recombinant CPSIT_0959 possesses cysteine desulfurase and PLP-binding activity, which removes sulfur from cysteine to produce alanine, and helps chlamydial replication. Our study shows that CPSIT_0959 improve the infectivity of offspring elementary bodies and seems to promote the replication by its product. This phenomenon has inhibited by the PLP-dependent enzymes inhibitor. Moreover, CPSIT_0959 increased expression of Bim and tBid, and decreased the mitochondrial membrane potential of host mitochondria to induce apoptosis in the latecycle for release of offspring. These results demonstrate that CPSIT_0959 has cysteine desulfurase and PLP-binding activity and is likely to contribute to apoptosis of the infected cells via a mitochondria-mediated pathway to improve the infectivity of progeny.

Curcumin Inhibits Proliferation and Epithelial-Mesenchymal Transition of Retinal Pigment Epithelial Cells Via Multiple Pathways

BACKGROUND

Proliferative vitreoretinopathy (PVR) is a disease caused by dedifferentiation, translocation and proliferation of several types of local cells. These cells form fibrocellular membranes resulting in detachment of retinal and vision loss. PVR occurs in 8%-10% of patients undergoing primary retinal detachment (RD) surgery and becomes a major obstacle for successful RD repair. Retinal pigment epithelial (RPE) cells are among the major cells which consist of fibrocellular membranes. Reproliferation and Epithelial-mesenchymal transition (EMT) are the primary pathological alteration of RPE cells in PVR.

METHODS

RPE cells were treated with curcumin at different concentrations for 24, 48 and 72 hours. The viable cells were detected by MTT assay. The apoptosis of RPE was stained by Multicaspase/7-AAD and detected using flow cytometry. Cell cycle analysis was quantified by PI staining. The mRNA levels were detected by real-time PCR. The protein levels were detected by western blot.

RESULTS

We found a compound curcumin significantly inhibited proliferation and EMT of RPE cells in vitro. Further study showed curcumin induced cell cycle arrest by activating G2 checkpoint through p53 pathway. Meanwhile, we found that curcumin suppressed the AKT, MAPK and TGF-β pathways in RPE cells which may also affect proliferation and EMT. Our research identified curcumin a potential novel agent for the PVR prevention and treatment. Curcumin induces cell cycle arrest by activating G2 checkpoint.

CONCLUSION

Our results in this study also provide the insights to broaden the application of curcumin in research and probably clinics.

Treponema pallidum flagellins stimulate MMP-9 and MMP-13 expression via TLR5 and MAPK/NF-κB signaling pathways in human epidermal keratinocytes

Syphilis is a chronic disease caused by Treponema pallidum and the pathogenesis is still unclear. T. pallidum infection induced inflammatory responses are involved in the immunopathological damage in skin and other tissues. Flagellin, the monomeric subunit of bacterial flagella, is a classic pathogen associated molecular patterns (PAMPs) that interacts to TLR5 and induces inflammatory responses. Keratinocytes, as immune sentinels recognize the PAMPs via TLRs, play an important role in skin innate immune response. Matrix metalloproteinases (MMPs) expressed by keratinocytes are involved in skin inflammatory responses and promoting pathogens invasion. In this study, we demonstrate that FlaB1, FlaB2 and FlaB3, the flagellins of T. pallidum, induced MMP-9 and MMP-13 production in human immortalized keratinocytes cell line HaCaT. Silencing of TLR5, but not TLR2 and TLR4 attenuated MMP-9 and MMP-13 expressions induced by T. pallidum flagellins. MMP-9 and MMP-13 expressions were also be abrogated by transfection with a dominant negative (DN) plasmid of MyD88. We also found that treatment of HaCaT cells with FlaB1, FlaB2 and FlaB3 activate the MAPK and NF-κB signaling pathways. Inhibited of ERK, JNK, p38 and NF-κB suppressed MMP-9 expression induced by the FlaB1. MMP-13 expression was found to be suppressed by pretreatment with inhibitors of ERK, JNK and NF-κB, but not p38. These findings demonstrate that T. pallidum flagellins (FlaB1, FlaB2 or FlaB3) can stimulate MMP-9 and MMP-13 expression through TLR5 and MAPK/NF-κB signaling pathways in human epidermal keratinocytes, which could contribute to the pathogenesis of T. pallidum infection.

Abstract P6-01-16: The phosphorylation-specific association of STMN1 with GRP78 promotes breast cancer metastasis

This abstract was not presented at the symposium.

Diagnostic value of recombinant Tp0821 protein in serodiagnosis for syphilis

Syphilis is a multistage sexually transmitted disease that remains a serious public health concern worldwide. The coexistence of Treponema pallidum with other closely related members of spirochaeta, such as Leptospira spp. and Borrelia burgdorferi, has complicated the serodiagnosis due to cross-reactive antigens. In this study, recombinant Tp0821 protein was expressed in Escherichia coli and purified by metal affinity chromatography. Then enzyme-linked immunosorbent assays (ELISAs) based on Tp0821 for the detection of specific antibodies were established. The relative positive rates of the IgM ELISA and the IgG ELISA were found to be 91·0 and 98·3%, respectively, when screening 578 syphilis specimens. The specificities were 94·3 and 100%, respectively, when cross-checking with serum samples obtained from 30 patients with Lyme disease, five patients with leptospirosis, and 52 uninfected controls. In addition, relative positive rates and specificities of Tp0821 for human sera were all 100% in Western blotting. When compared to the syphilis diagnostic tests commonly used in clinical settings, we found that the results of Tp0821-based ELISAs correlated well with the results of the treponemal tests, specifically the T. pallidum particle agglutination (TP-PA) test and the chemiluminescent immunoassay (CIA). Thus, these findings identify Tp0821 as a novel serodiagnostic candidate for syphilis.

SIGNIFICANCE AND IMPACT OF THE STUDY

In this study, we expressed and purified the Treponema pallidum protein Tp0821 and developed Tp0821-based enzyme-linked immunosorbent assays (ELISAs) for the detection of specific antibodies. The serodiagnostic performance of the recombinant protein was then evaluated. When compared to the results of syphilis diagnostic tests commonly used in clinical settings, we found that the reactivities of syphilitic sera with the recombinant antigen correlated well with the results of the treponemal tests, specifically the T. pallidum particle agglutination (TP-PA) test and the chemiluminescent immunoassay (CIA). Thus, the recombinant protein shows promise as a new diagnostic antigen in the ELISAs.

A novel ELISA using a recombinant outer membrane protein, rTp0663, as the antigen for serological diagnosis of syphilis

BACKGROUND

The lack of Treponema pallidum-specific antigens with highly accurate diagnosis makes the diagnosis of syphilis challenging.

METHODS

A soluble recombinant version of a new diagnostic protein Tp0663 has been produced. The serodiagnostic potential of this protein was assessed by screening 3326 serum samples simultaneously evaluated by rapid plasma reagin and T. pallidum particle agglutination tests. Kappa (κ) coefficients were used to compare the concordance between clinical diagnosis and the Tp0663-based ELISA or the ARCHITECT Syphilis TP chemiluminescent immunoassay (Abbott GmbH and Co. KG).

RESULTS

Using the results of clinical diagnosis as the gold standard, the sensitivity and specificity of Tp0663 were found to be 98.83% (95% confidence interval (CI) 96.61-99.60%) and 100% (95% CI 99.88-100%), respectively. In comparison, the ARCHITECT Syphilis TP assay was found to have a lower sensitivity (97.27%, 95% CI 94.46-98.67%) and specificity (99.61%, 95% CI 99.32-99.78%). In particular, the ARCHITECT Syphilis TP exhibited a false-positive rate of 0.39%. Moreover, the ELISA was in perfect agreement with the gold standard, with a κ value of 0.99, comparable to that of ARCHITECT Syphilis TP (0.96).

CONCLUSION

These results identified Tp0663 as a novel serodiagnostic candidate with great potential for developing novel tests for the diagnosis of syphilis.

Numerical study of variable-density flow and transport in unsaturated-saturated porous media

Dense contaminant or solute transport in the unsaturated-saturated aquifer commonly exists in the natural environment. However, the influence of hydraulic properties of the unsaturated soil on penetration process of variable density flow in an unsaturated-saturated aquifer system is rarely investigated. In this study, a variable density, variably saturated flow and transport model based on FEFLOW is used to systematically investigate the penetration process of the solute through the unsaturated-saturated aquifer system, with a focus on the influence of the hydraulic parameters of the unsaturated soil on the penetration process. Vertical center of mass, and its speed and acceleration, are used to identify different stages of the penetration process through the unsaturated-saturated aquifer. The hydraulic parameters in the van Genuchten-Mualem model (VGM) affect the water content distribution in the unsaturated zone, subsequently the penetration time through the unsaturated zone. Through influencing the thickness of the transition zone (0.1-0.9 maximum concentration of the plume) when the plume reaches the water table, the hydraulic parameters affect the accumulation time of the solute at the boundary layer in the saturated zone. Thus, the process in not only the unsaturated but also the saturated zones is influenced by the change of the hydraulic properties of the unsaturated zone. Furthermore, the results show that the instabilities start to occur at the zone with high water content (90% of maximum saturation) in the capillary fringe. Freshwater intrudes into the zone with high water content when fingers are completely developed at the entire system. The length of freshwater intrusion above the water table has a negative correlation with the fitting parameter alpha in the VGM model. The influence of the density difference of the solute on the penetration processes is insignificant in the unsaturated zone but significant in the saturated zone. Sensitive analysis for the hydraulic properties of the unsaturated soil on the penetration process shows that pore size distribution index is the main factor influencing the penetration time through the unsaturated zone, the penetration time through the entire aquifer, the accumulation time at the boundary layer, and the development time of the fingers. Two other parameters, fitting parameter alpha and residual saturation, have minor effects.

Increased Water Storage in the Qaidam Basin, the North Tibet Plateau from GRACE Gravity Data

Groundwater plays a key role in maintaining the ecology and environment in the hyperarid Qaidam Basin (QB). Indirect evidence and data from sparse observation wells suggest that groundwater in the QB is increasing but there has been no regional assessment of the groundwater conditions in the entire basin because of its remoteness and the severity of the arid environment. Here we report changes in the spatial and temporal distribution of terrestrial water storage (TWS) in the northern Tibetan Plateau (NTP) using Gravity Recovery and Climate Experiment (GRACE) data. Our study confirms long-term (2003–2012) TWS increases in the NTP. Between 2003 and 2012 the TWS increased by 88.4 and 20.6 km³ in the NTP and the QB, respectively, which is 225% and 52% of the capacity of the Three Gorges Reservoir, respectively. Soil and water changes from the Global Land Data Assimilation System (GLDAS) were also used to identify groundwater storage in the TWS and to demonstrate a long-term increase in groundwater storage in the QB. We demonstrate that increases in groundwater, not lake water, are dominant in the QB, as observed by groundwater levels. Our study suggests that the TWS increase was likely caused by a regional increase in precipitation and a decrease in evaporation. Degradation of the permafrost increases the thickness of the active layers providing increased storage for infiltrated precipitation and snow and ice melt water, which may also contribute to the increased TWS. The huge increase of water storage in the NTP will have profound effects, not only on local ecology and environment, but also on global water storage and sea level changes.

Identification of Campylobacter jejuni and determination of point mutations associated with macrolide resistance using a multiplex TaqMan MGB real-time PCR

AIMS

The aim of the study was to develop a multiplex real-time PCR method to identify Campylobacter jejuni containing mutations commonly associated with macrolide resistance.

METHODS AND RESULTS

A multiplex fluorescence real-time PCR assay was developed based on TaqMan minor groove binder (MGB) probes. The VS1-MGB probe was designed based on the VS1 gene and was used to identify Camp. jejuni. The 23S rDNA-MGB probe was designed to distinguish macrolide resistance mutations in 23S rDNA, while 57D-MGB and 74D-MGB were designed to detect resistance mutations in ribosomal protein L4. The specificity and accuracy of our method were identical to the conventional biochemical tests, mapA PCR, minimum inhibitory concentration (MIC) determination and DNA sequencing. The linear detection limit of the method was 0·03 ng genomic DNA and three colony formation unit (CFU) per reaction. In 6 of 18 cases, the nature of Erythromycin resistance could be correctly determined from natural isolates; absence of the tested mutations was demonstrated in the remaining four resistant isolates.

CONCLUSIONS

A multiplex TaqMan MGB real-time PCR assay with high specificity and accuracy was developed to simultaneously identify Camp. jejuni and detect the gene mutations associated with macrolide resistance.

SIGNIFICANCE AND IMPACT OF THE STUDY

This multiplex method can potentially simplify the identification of Camp. jejuni and determine macrolide resistance due to mutations in 23S rDNA or ribosomal protein L4. This method has a potential for application in different research areas and molecular surveillance.

Effect of intermittent normobaric hyperoxia for treatment of neuropathic pain in Chinese patients with spinal cord injury

STUDY DESIGN

Prospective, randomized and controlled study.

OBJECTIVES

The aim of the study was to investigate the effect of intermittent normobaric hyperoxia (InHO) for treatment of neuropathic pain in patients with spinal cord injury (SCI).

SETTING

The First Affiliated Hospital of Nanhua University, Hengyang, Hunan Province, China.

METHODS

Patients with SCI from Hunan Province were recruited from the First Affiliated Hospital of Nanhua University. History, duration, localization and characteristics of pain were recorded. Visual analog scale (VAS), the Patient Global Impression of Change (PGIC) and Short Form-36 walk-wheel (SF-36ww) was used to investigate the effect of InHO. Patients were randomly assigned to study and control groups. In study group, patients were exposed to pure oxygen via non-rebreathing reservoir mask, which increased the provided oxygen at a rate of 7 l min^-1 for 1 or 4 h daily in 2 weeks. While in control group, patients breathed air via non-rebreathing reservoir mask at the same rate.

RESULTS

A total of 62 SCI patients with neuropathic pain were included in the study. The mean age of the patients was 36.85±10.71 years. Out of 62 patients, 21 were tetraplegic and 41 were paraplegic. Overall, 14 patients had complete SCI while 48 patients had incomplete injuries. Three groups were similar with respect to age, gender, duration, smoker or not, level and severity of injury. In the 4 h per day InHO groups, a statistically significant reduction of the VAS values was observed (P<0.05). Significant difference was also found in SF-36ww pain scores and PGIC (P<0.05). However, such an effect was not evident in the control group.

CONCLUSION

This study revealed that in treatment of neuropathic pain of SCI patients, InHO may be effective.

PERSPECTIVE

This article presents InHO may effectively complement pharmacological treatment in patients with SCI and neuropathic pain.

Filtration and clogging of permeable pavement loaded by urban drainage

Permeable pavement, as a sustainable infrastructure material can promote hydrologic restoration, particulate matter (PM) and solute control. However, filtration and commensurate clogging are two aspects of continued interest and discussion. This study quantifies filtration and clogging of cementitious permeable pavement (CPP) for loadings from 50 to 200 mg/L of hetero-disperse sandy-silt PM. The CPP mix design provides a hetero-disperse pore size distribution (PSD)(pore), effective porosity (φ(e)) of 24% and median pore size of 658 μm with a standard deviation of 457 μm. The PM mass separation across the entire particle size distribution (PSD)(PM) exceeds 80%; with complete separation for PM greater than 300 μm and 50% separation for suspended PM. Turbidity is reduced (42-95%), and effluent is below 10 NTU in the first quartile of a loading period. Permeable pavement illustrates reductions in initial (clean-bed) hydraulic conductivity (k(0)) with loading time. For all PM loadings, k(0) (3.1 × 10(-1) mm/s) was reduced to 10(-4) mm/s for runoff loading durations from 100 to 250 h, respectively. Temporal hydraulic conductivity (k) follows exponential profiles. Maintenance by vacuuming and sonication illustrate that 96-99% of k(0) is recovered. Permeable pavement constitutive properties integrated with measured PM loads and a year of continuous rainfall-runoff simulation illustrate k reduction with historical loadings. Study results measure and model filtration and hydraulic conductivity phenomena as well as maintenance requirements of permeable pavement directly loaded by urban drainage.

Monosodium luminol upregulates the expression of Bcl-2 and VEGF in retrovirus-infected mice through downregulation of corresponding miRNAs

The retrovirus ts1 is a mutant of Moloney murine leukemia virus (MoMuLV) that causes neurodegeneration (ND) in susceptible mice. Our previous studies showed that the antioxidant drug monosodium luminol (GVT) prevented the development of ND in ts1-infected mice. In this study, we analyzed effect of GVT on the expression of B-cell lymphoma-2 protein (Bcl-2) and vascular endothelial growth factor (VEGF) in central nervous system (CNS) tissues of these animals. Our data showed that GVT treatment of ts1-infected mice significantly increased their expression of Bcl-2 and VEGF in brainstem compared with ts1-infected untreated mice. We also studied the expression of specific microRNAs (miRNAs) such as miRNA-15 and -16 (targeting Bcl-2), and miRNA-20 (targeting VEGF). We found that the expression of miRNAs inversely correlated with the upregulation of their target proteins in ts1-infected untreated as well as in GVT-treated-ts1-infected mice. The data showed that GVT treatment prevented ts1-induced ND at least in part by upregulating Bcl-2 and VEGF expression, what likely occurred as a consequence of downregulation of their corresponding miRNAs.

Gene Expression of Manganese-Containing Superoxide Dismutase as a Biomarker of Manganese Bioavailability for Manganese Sources in Broilers

The goal of this study was to determine whether Mn-containing superoxide dismutase (MnSOD) gene expression in heart tissue would reflect differences among bioavailabilities of Mn sources earlier than other indices. Broilers were divided into 5 groups and fed a Mn-unsupplemented basal diet (control) or the basal diet supplemented with 120 mg of Mn/kg as Mn sulfate or Mn methionine E (Mn Met E), Mn amino acid B (Mn AA B), or Mn amino acid C (Mn AA C) with weak, moderate, or strong chelation strength, respectively. Heart MnSOD mRNA levels were analyzed using quantitative reverse transcription-PCR at 7, 14, or 21 d. The results showed that heart MnSOD mRNA level increased as dietary Mn level increased at any age. At 7 d, chicks fed the diet supplemented with Mn AA B had higher MnSOD mRNA levels than those fed the diet supplemented with Mn sulfate and Mn Met E, and the same tendency was observed at 14 or 21 d. The results suggest that MnSOD gene expression, which is regulated by dietary Mn at transcriptional level, could reflect differences among bio-availabilities of organic Mn sources as early as 7 d. Therefore, the estimation of relative bioavailabilities of Mn sources based on heart MnSOD mRNA level could require a shorter experimental period and a smaller number of animals, and thus less cost.

Neuroprotective role of Z-ligustilide against forebrain ischemic injury in ICR mice

Radix Angelica sinensis, known as Danggui in Chinese, has been used to treat cardiovascular and cerebrovascular diseases in Traditional Chinese Medicine for a long time. Modern phytochemical studies showed that Z-ligustilide (LIG) is the main lipophilic component of Danggui. In this study, we examined whether LIG could protect ischemia/reperfusion-induced brain injury by minimizing oxidative stress and anti-apoptosis. Transient forebrain cerebral ischemia (FCI) was induced by the bilateral common carotid arteries occlusion for 30 min. LIG was intraperitoneally injected to ICR mice at the beginning of reperfusion. As determined via 2,3,5-triphenyl tetrazolium chloride (TTC) staining at 24 h following ischemia, the infarction volume in the FCI mice treated without LIG (22.1 +/- 2.6%) was significantly higher than that in the FCI mice treated with 5 mg/kg (11.8 +/- 5.2%) and 20 mg/kg (2.60 +/- 1.5%) LIG (P < 0.05 or P < 0.01). LIG treatment significantly decreased the level of malondialdehyde (MDA) and increased the activities of the antioxidant enzyme glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD) in the ischemic brain tissues (P < 0.05 or P < 0.01 vs. FCI group). In addition, LIG provided a great increase in Bcl-2 expression as well as a significant decrease in Bax and caspase-3 immunoreactivities in the ischemic cortex. The findings demonstrated that LIG could significantly protect the brain from damage induced by transient forebrain cerebral ischemia. The antioxidant and anti-apoptotic properties of LIG may contribute to the neuroprotective potential of LIG in cerebral ischemic damage.

Use of chemical characteristics to predict the relative bioavailability of supplemental organic manganese sources for broilers1

Twelve organic Mn sources and MnSO4 were evaluated by polarographic analysis and via solubility in buffers (pH 5 and 2) and deionized water. Fractions from solubility tests were evaluated by gel filtration chromatography for structural integrity. Organic Mn sources included five Mn methionine complexes (Mn Met A to Mn Met E), two Mn proteinates (Mn Pro A and Mn Pro B), and five Mn amino acids (Mn AA A to Mn AA E). Sources varied considerably in chemical characteristics. Chelation strength (Qf) ranged from weak (1.9 Qf-values) to strong complexes (115.4 Qf-values). No complexed Mn was found in filtrates at pH 2.0 or 5.0. A 42-d bioassay was used to estimate relative bioavailability of Mn sources for chicks fed diets supplemented with 60, 120, or 180 mg Mn/kg. Bone Mn, heart Mn, heart manganese-superoxide dismutase activity (MnSOD), and heart MnSOD mRNA increased (P < 0.001) as dietary Mn increased. Only heart MnSOD mRNA tended (P < 0.10) to differ among dietary Mn sources. For bioassays of Mn, the MnSOD mRNA level in heart was more sensitive than the MnSOD activity in heart or other indices. Relative to MnSO4 (assigned 100%), slope ratios of MnSOD mRNA levels in heart gave bioavailabilities of 99, 132, and 113% for Mn Met E, Mn AA B, and Mn AA C sources with weak, moderate, and strong chelation strength, respectively. The bioavailability of Mn was more closely related to chelation strength as measured by polarography than to chemical traits assessed by solubility or structural integrity.

[Effects of Rg1 on calcium channel of guinea pig ventricular myocytes]

OBJECTIVE

To evaluate the effect of Rg1 (purified saponin of Panax notoginseng) on L-Ca2+ channel of guinea pig ventricular myocytes.

METHOD

The whole-cell patch clamp recording technique.

RESULT

When the holding potential was kept at -40 mV, and the cell was depolarized to +40 mV for 150 ms at a frequency of 0.5 Hz.Rg1 10 mumol.L-1 and 30 mumol.L-1 could not reduce Bay K 8644 and nifedipine-sensitive L-type Ca2+ inward current (P > 0.05, n = 5).

CONCLUSION

Rg1 should not be a Ca2+ channel antagonist.

[Effect of enoxacin on pharmacokinetics of theophylline in rats]

In order to obtain an experimental evidence for Enoxacin(ENX) to be correctly used in clinical treatment, we studied the effect of ENX on the pharmacokinetic parameters of theophylline(TP). A single oral dose of TP 20 mg/kg was given to rats and ENX(300 mg/kg, 450 mg/kg) was co-administered orally three times to those rats. The plasma concentrations of TP were determined by HPLC after TP was administered 1, 2, 3, 5, 7, 12 and 24 hrs. The results showed that TP was eliminated by one compartment model. TP plasma concentrations and AUC were significantly increased. T1/2 beta of TP was prolonged. The total clearance of TP was decreased when compared with the control. This interaction was dose-dependent. It was concluded that the interaction between ENX and TP existed. Concomitant use of ENX with TP should be avoided.

[Determination of normal temperature properties of refractory die material compatible with slip casting core of sintered titanium powder]

OBJECTIVE

The refractory die is the precondition for developing slip casting core of sintered powder. This study is to determine the normal temperature properties of the refractory die material compatible with slip casting core.

METHODS

to mix the die material at five different ratios (8/1, 7.5/1, 7/1, 6.5/1, and 6/1) and measure their solidification time with self-manufactured Vicker's needle; to prepare five cylindrical specimens (phi 10 x 15 mm) in different drying time for determining their compressive strength, and then to let another five specimens fire at 1000 degrees C four times for measuring the residual compressive strength at room temperature.

RESULTS

The setting time was 16.25 minutes (7.5/1), and the lower the powder-liquid ratio, the longer the setting time. The normal compressive strength was 25.32 MPa (drying 24 hours), while the longer the drying time, the higher the compressive strength achieved (P < 0.01). The residual compressive strength was 24 MPa.

CONCLUSION

The normal temperature properties of the refractory die material meet the demand of slip casting core of sintered powder.

[Effects of occupational exposure to formamidines on cardiovascular functions]

OBJECTIVE

To understand the possible effects of occupational exposure to formamidines on human cardiovascular function, this study was carried out.

METHODS

Sixteen farmers spraying chlordimeform, 14 packers packaging chlordimeform and 23 packers packaging mono-formamidine were followed-up pre- and post-exposure. Their urinary excretion of formamidine or its metabolite, as well as air concentrations of formamidine at their work places and their skin contamination with it were measured to estimate the exposure level. Furthermore, 24-hour urinary level of vanillinmandelic acid (VMA) was analyzed among mono-formamidine packers.

RESULTS

Their whole body skin contaminated with 3.240 and 2.142 g/cm(2) of chlordimeform in the sprayers and packers, respectively. Their hand skin contaminated with mono-formamidine at 6.59 g/cm(2) in the packers. It indicated that the major route of exposure to formamidine was skin contamination. Urinary levels of formamidines or their metabolites increased significantly after exposure, reaching 6.194 and 3.378 micromol/L for the sprayers and packers exposed to chlordimeform, respectively, and 2.760 - 3.427 micromol/L for mono-formamidine in the packers. Their heart rates slowed down, P-R and Q-T intervals prolonged and blood pressure reduced after exposure, as compared with those before exposure. Consistency of the results in several studies demonstrated that formamidines could induce changes in the indices for cardiovascular functions under the relatively low exposure levels at present. Decrease of urinary VMA from 0.068 micromol/L pre-exposure to 0.040 - 0.055 micromol/L post-exposure suggested that catecholamine could play a role in these effects.

CONCLUSION

Formamidines has certain effects on human cardiovascular function. It is suggested that attention be paid to the changes in cardiovascular functions of those exposed in their health surveillance.

[Determination of high temperature compressive strength and refractory degree of die material compatible with slip casting core of sintered titanium powder]

OBJECTIVE

The refractory die is the precondition for developing slip casting core of sintered powder. This study is to determine the high temperature properties of the refractory die material compatible with slip casting core.

METHODS

To prepare three cylindrical specimens (phi 10 x 15 mm) and determine their compressive strength at 1000 degrees C: to make four specimens in flat-topped cone for determining the practical refractory degree by decreasing the pressing temperatures in a sequence of 1420, 1400, 1350 and 1100 degrees C.

RESULTS

The compressive strength of this material was 17.8 MPa at 1000 degrees C. Its practical refractory degree was higher than 1100 degrees C.

CONCLUSION

The high temperature properties of the refractory die material that we developed meet the demand of slip casting core of sintered powder.

[Determination of major expansion properties of refractory die material compatible with slip casting core of sintered titanium powder]

OBJECTIVE

To determinate major expansion properties of refractory die material.

METHODS

The setting expansion ratio of refractory die material for slip casting core of sintered titanium powder at room temperature was performed, as well as thermal expansion ratio from room temperature to 800 degrees C.

RESULTS

The maximum setting expansion ratio in 2 hours reached 0.3407%; The final setting expansion ratio in 24 hours was 0.3117%; The mean thermal expansion coefficient was mainly in range of 8 x 10(-6)-11 x 10(-6)/degree C; The expansion property seemed very stable after sintering repeatedly and the small shrinkage after sintering could be compensated with the die spacer and setting expansion.

CONCLUSION

The expansion properties of the refractory die material that we synthesized can fulfil the application requirements of slip casting core of sintered titanium powder.

Isolation and characterisation of neurotoxigenic Clostridium butyricum from soil in China

Soil specimens collected from a site around the home of patients with food-borne type E. botulism probably caused by neurotoxigenic Clostridium butyricum in Guanyun, Jiangsu province, China, were examined for the presence of neurotoxigenic C. butyricum. Five lakeside sites of Weishan lake, in an area near to the sites where the type E. botulism outbreaks caused by neurotoxigenic C. butyricum occurred were also surveyed. Type E toxin-producing C. butyricum was isolated from soil from four sites including the site in Guanyun. Polymerase chain reaction assay demonstrated the presence of the type E toxin gene in all the toxigenic isolates. The biochemical properties of the isolates from the Guanyun soil and the lakeside soil were identical except for inulin fermentation and starch hydrolysis properties. These results indicate that neurotoxigenic C. butyricum has its principal habitat in soil.