[Investigation and analysis of occupational hazards in construction of power transmission and transformation project].

Objective: To investigate the occupational hazard factors and exposure levels of workers during the construction of power transmission and transformation projects. Methods: Analysis and identification of occupational hazard factors were carried out for typical construction process of 6 power transmission projects and 3 substation projects in September 2018. The on-site occupational health investigation was carried out to detect and analyze the exposure levels of workers to occupational hazard factors. Results: The time weighted average concentration (C(TWA)) of crushing workers exposed to silica dust and welders exposed to welding fume in substation projects were 2.72 and 14.03 mg/m(3), respectively. The 8 h equivalent sound level results of exposure noise of carpenters in power transmission projects and crushing workers, reinforcement workers, carpenters, scaffolders, road builders in substation projects were 87.9, 92.5, 87.1, 92.5, 93.0 and 90.2 dB (A) , respectively. The 4-hour time equal energy frequency weighted vibration acceleration of hand-transmitted vibration of bricklayer in power transmission projects, bricklayer, general worker 3, road builder 1 and road builder 2 of substation projects were 5.36, 5.21, 5.28, 10.71 and 5.22 m/s(2), respectively. The effective irradiance of electric welding arc light of welders' limbs in power transmission projects and substation projects were 401.19, 319.68 µW/cm(2), respectively. All of the above exceeded the requirements of occupational exposure limits. The occupational radiation levels and exposure limits of hazardous chemical factors met the requirements of each post. Conclusion: During the construction of power transmission and transformation projects, the exposure levels of occupational hazard factors in multiple posts exceed the standard. The main responsibility of employers for occupational disease prevention and control should be implemented, and targeted comprehensive measures should be taken to reduce the exposure levels of occupational hazard factors of workers.

[Interventional effect of asiaticosdide on rats exposed to silica dust].

Objective: To investigate the effect of asiaticoside for fibrosis in lung tissues of rats exposed to silica and to explore its possible mechanism. Methods: 144 SD male rats were randomly divided into control group, model group, positive drug control group, asiaticoside high-dose group, medium-dose group and low-dose group, each group included 24 rats. Rats in the control group were perfused with 1.0 ml of normal saline, and the other groups were given 1.0 ml 50 mg/ml SiO(2) suspension. Gavage of herbal was given from the next day after model establishment, once a day. Rats in the positive drug control group were administration with 30 mg/kg tetrandrine and rats in the low-dose group, medium-dose group and high-dose group were given 20 mg/kg, 40 mg/kg and 60 mg/kg asiaticoside for fibrosis respectively. Rats in the control group and the model group were given 0.9% normal saline. The rats were sacrificed in on the 14th, 28th and 56th day after intragastric administration and collect the lung tissues to detect the content of hydroxyproline, TGF-ß(1) and IL-18, observe the pathological changes of the lung tissues by HE and Masson staining and determine the expressions of Col-I, a-SMA, TGF-ß in lung tissues by Western Blot. Results: On the 14th day, 28th day and 56th day after model establishment, the lung tissues of rats in the model group showed obvious inflammatory response and accumulation of collagen fibers, and the degree of inflammation and fibrosis increased with time. The intervention of asiaticoside could effectively inhibit the pathological changes of lung tissues. The contents of hydroxyproline, IL-18 and TGF-ß1 in lung tissues of model group were higher than those in the control group (P<0.05) , while the level of hydroxyproline, IL-18 and TGF-ß1 in asiaticoside groups were significantly decreased, and the difference was statistically signicant (P<0.05) . Compared with the control group, the expression levels of Col-I, TGF-ß1and α-SMA in lung tissue of model group were increased (P<0.05) , while the expression level of Col-I, TGF-ß1 and α-SMA were decreased after the intervention of asiaticoside, and the difference was statistically signicant (P<0.05) . Conclusion: Asiaticoside can inhibit the increase of Col-I, TGF-ß1 and α-SMA content in the SiO(2)-induced lung tissues of rats, reduce the release of TGF-ß1 and IL-18 inflammatory factors in lung tissue, and then inhibit the synthesis and deposition of extracellular matrix in rat lung tissue, and improve silicosis fibrosis.

[The treatment proposal for the patients with breast diseases in the central epidemic area of 2019 coronavirus disease].

Currently, the epidemic of 2019 coronavirus disease (COVID-19) is still ongoing. Its characteristics include high contagiousness, herd susceptibility and clinical phenotype diversity, which have a severe influence on people's daily life and rountine therapy for other diseases. Breast dieases are clinical common diseases. In the central epidemic area of COVID-19, the clinical specialists of breast diseases should consider all of the following factors comprehensively: the prevention of COVID-19, the diagnosis and treatment of breast diseases and the accessibility of medical resources. Besides, we should select the appropriate therapy and optimize treatment process so as to prevent the propagation and cross infection of COVID-19 as well as manage the breast diseases without delay. Therefore, we carried out some management proposals of the patients with breast diseases in the central epidemic area during the epidemic of COVID-19 on the basis of conventional treatment guidelines and clinical experiences. The suggestions and corrections from colleagues will be welcomed.

[Effect of microRNA-27a-3p on proliferation, apoptosis and cell cycle of hepatoma cells].

Objective: To investigate the effect of miR-27a-3p on proliferation, apoptosis and cell cycle of hepatoma cells. Methods: A quantitative real-time polymerase chain reaction (qPCR) was used to detect differential expression of miR-27a-3p in normal hepatic epithelial cells (L02) and hepatoma cells (HepG2 and PLC). Cell experiment was divided into four groups: HepG2 overexpression cells, Mi-27a-3p overexpression group (Mi-27a) and negative control group (Mi-Con); PLC knockdown cells, Mi-27a-3p knockdown group (Mi-inhibitor-27a) and negative control group (Mi-inhibitor-Con). The expression of microRNA-27a-3p in each group after transfection was detected by qPCR analysis. MTT assay was used to detect the cell proliferation. Flow cytometry was used to detect the apoptosis and cell cycle. One-way ANOVA was used for multiple comparisons, and t-test was used to compare two groups. Results: qPCR results showed that the expression levels of miR-27a-3p in L02, HepG2 and PLC increased sequentially, and the relative expression levels were 1.07 ± 0.04, 4.81 ± 0.64 and 11.31 ± 0.92, respectively (P < 0.05). MTT assay showed that the cell viability of HepG2 cells transfected with miR-27a-3p overexpression plasmid was significantly decreased compared with the negative control group (P < 0.05). The apoptosis assay showed that the apoptosis rate of miR-27a-3p overexpression group was higher than the negative control group (P < 0.05). The cell cycle results showed that the proportion of S phase cells in the miR-27a-3p overexpression cell group was significantly lower than the negative control group (P < 0.05). Furthermore, microRNA-27a-3p knockdown validation in PLC cells showed that MTT, apoptosis and cell cycle tests results were opposite to the results of HepG2 overexpression cells, and the differences were statistically significant (P < 0.05). Conclusion: miR-27a-3p can significantly inhibit the proliferation of hepatoma cells, promote cell apoptosis, alter the cell cycle distribution, and may become a potential target in hepatocellular carcinoma therapy.

Quantitative Expression of RNA from Frozen Organs and Formaldehyde-fixed and Paraffin-embedded Tissues.

ABSTRACT: Objective Quantitative analysis and comparison of the expression of ribonucleic acid （RNA） from frozen organs and formaldehyde-fixed and paraffin-embedded （FFPE） tissues. Methods Frozen specimens of human brain, myocardium and liver tissues as well as FFPE samples at different postmortem intervals were collected and mass concentration of RNA was extracted and detected. Reverse transcription-quantitative polymerase chain reaction （RT-qPCR） technology was used to analyze the amplification efficiency and relative expression of each RNA marker. Results The mass concentration and integrity of RNA extracted from FFPE samples were relatively low compared with frozen specimens. The amplification efficiency of RNA markers was related with RNA species and the length of amplification products. Among them, glyceraldehyde-3-phosphate dehydrogenase （GAPDH） and ß-actin （ACTB） with relatively long amplification products failed to achieve optimal amplification efficiency, whereas 5S ribosomal RNA （5S rRNA） achieved ideal amplification efficiency and showed quite stable expression across various tissues, therefore it was chosen as internal reference marker. The expression quantity of GAPDH and ACTB in frozen specimens with longer postmortem intervals and in FFPE samples with relatively long amplification products was decreased. The expressions of tissue-specific microRNAs （miRNAs）, GAPDH and ACTB with relatively short amplification products had consistency in the same tissues and FFPE samples. Conclusion Through standardizing the RT-qPCR experiment, selecting the appropriate RNA marker and designing primers of appropriate product length, RNA expression levels of FFPE samples can be accurately quantified.

Genetic polymorphism of human leucocyte antigen and susceptibility to multidrug-resistant and rifampicin-resistant tuberculosis in Han Chinese from Hubei Province.

We determined the high-resolution allele and haplotype frequencies at the human leucocyte antigen (HLA)A, B and DRB1 loci in the Han population of Hubei province, the TB endemic area of Central China, with pulmonary tuberculosis (PTB), and established the relationship between HLA-A, B and DRB1 alleles as well as haplotypes and susceptibility to multidrug-resistant and rifampicin-resistant tuberculosis (MDR/RR-TB). Blood samples were drawn from 174 patients with MDR/RR-TB and 838 patients with drug-susceptible PTB in ethnic Han population from Hubei province (central China). Four-digit allele genotyping of HLA- A, B and DRB1 loci was performed using polymerase chain reaction with sequence-specific oligonucleotide probes (PCR- SSOP). The allele and haplotype frequencies of HLA-A, B and DRB1 were determined and compared between patients with MDR/RR-TB and patients with drug-susceptible PTB. Statistical analysis of the generated data indicated no departure from expectation of Hardy-Weinberg equilibrium (HWE) at all loci of the control group. Multivariate analysis identified allele DRB1*08:01 (p < .0001; OR = 174.5, 95% CI 15.3-1987.2) as independent predictor of MDR/RR-TB, except for old age (p < .0001; OR = 10. 9, 95% CI 7.6-15.8), previous treatment history (p < .0001; OR = 11.0, 95% CI 7.2-16.7) and poor compliance to treatment (p < .0001; OR = 12.9, 95% CI 8.4-20.0). While in the subgroup of new TB cases, DRB1*08:01 (p < .0001; OR = 80.3, 95% CI 7.0-917.1) and older age (p < .0001; OR = 3.9, 95% CI 2.4-6.4) were independent susceptibility factors for primary MDR/RR-TB. Our results suggest that a combination of clinical and host genetic information about tuberculosis patients may contribute to prediction and early detection of MDR/RR-TB.

[Protective effect and mechanism of tHBQ on acute silica dust exposure in rats].

Objective: To study the protective effects and possible mechanisms of tBHQ in rats exposed to acute silicadust. Methods: Male Wistar rats without specific pathogen SPF were randomly divided into control group、model group and intervention group, 32 rats for each group. Rats in the model group and the intervention group were treated with a single non exposed tracheal dust method to establish the rats exposed to silica model. The intervention group was intervened with 1% tBHQ solution, once a day. Each group 8 rats were sacrificed at 3,14,28,60d, respectively.The contents of IL-1,TNF-α, HYP,TGF-ß in the lung tissue of rats were determined by enzyme linked immunosorbent assay(ELISA), the contents of MDA and the GSH-PX activity in lung tissue and serum of rats were determined by colorimetry. Results: Compared with the control group, the contents of IL-1 in the lung tissue of the model group and the intervention group at each time point increased with time, the contents of IL-1 of model group reached the maximum at 60d, the contents of IL-1 in intervention group reached the maximum at 28d(P<0.05), except 3 d. Compared with the control group, the contents of TGF-ß and HYP in the lung tissue of the model group and the intervention group at 28 and 60 d increased with time and reached the maximum at 60d(P<0.05). Compared with the model group at each time point, the contents of IL-1, TGF-ß, HYP in the intervention group were lower than those in the model group(P<0.05). Compared with the control group, the contents of MDA in lung tissue and serum of rats in model group and intervention group at different time points increased with time(P<0.05). Compared with the control group,the activity of GSH-PX in serum and lung tissue of rats in model group and intervention group decreased with time,there was no significant difference in 3d(P<0.05), compared with the control group, the activity of GSH-PX in the lung and serum tissue of in-tervenetion group was higher than model group except the 3d(P<0.05). Conclusion: The intervention of tBHQ can alleviate oxidative stress in rats exposed to silica dust to some extent, improve the antioxidant capacity of the body, and reduce the contents of IL-1, TNF-α, TGF-ß,HYP in lung tissue,it has acertain impediment and inhibition effect on the inflammation and fibrosis caused by acute silica dust exposure.

[Effect of radiation dose and dose rate on pulmonary fibrosis in mice].

OBJECTIVE: To study the effect of radiation dose and dose rate on radiation-induced pulmonary fibrosis in mice. METHODS: Twenty-four C57BL/6 mice were randomly divided into a control group (n=6) and an irradiation group(n=18). The irradiation group was further assigned to 3 subgroups according to the whole lung radiation with 15 Gy at 400 cGy/min, 20 Gy at 400 cGy/min and 20 Gy at 100 cGy/min, while the control group received sham-irradiation. All mice were scanned with computed tomograph (CT) 20 weeks post-irradiation, and then they were sacrificed and lung tissues were collected. H&E staining, sirius red staining, lung fibrosis scored and hydroxyproline content analysis were used to assess lung fibrosis and collagen deposition. Real time PCR was used to measure the mRNA expression of type Ⅰ collagen. Immunohistochemical staining was used to detect the activatin and distribution of a-SMA(+) -myofibroblasts. RESULTS: Compared to the control group, mice from irradiation groups exhibited significant pulmonary consolidation and collagen deposition.At the same dose rate, the higher irradiated dose used, the more severe pulmonary fibrosis was.On the other hand, with the same dose, the dose rate had less effect on pulmonary fibrosis. CONCLUSION: The effect of radiation dose on the degree of pulmonary fibrosis in mice is more than effect of the dose rate.

[Correlation between RNA Expression Level and Early PMI in Human Brain Tissue].

OBJECTIVES: To explore the correlation between the expression levels of several RNA markers in human brain tissue and early postmortem interval （PMI）. METHODS: Twelve individuals with known PMI （range from 4.3 to 22.5 h） were selected and total RNA was extracted from brain tissue. Eight commonly used RNA markers were chosen including ß-actin, GAPDH, RPS29, 18S rRNA, 5S rRNA, U6 snRNA, miRNA-9 and miRNA-125b, and the expression levels were detected in brain tissue by real-time fluorescent quantitative PCR. The internal reference markers with stable expression in early PMI were screened using geNorm software and the relationship between its expression level and some relevant factors such as age, gender and cause of death were analyzed. RNA markers normalized by internal reference were inserted into the mathematic model established by previous research for PMI estimation using R software. Model quality was judged by the error rate calculated with estimated PMI. RESULTS: 5S rRNA, miRNA-9 and miRNA-125b showed quite stable expression and their expression levels had no relation with age, gender and cause of death. The error rate of estimated PMI using ß-actin was 24.6%, while GAPDH was 41.0%. CONCLUSIONS: 5S rRNA, miRNA-9 and miRNA-125b are suitable as internal reference markers of human brain tissue owing to their stable expression in early PMI. The expression level of ß-actin correlates well with PMI, which can be used as an additional index for early PMI estimation.

Effects of different dietary starch sources on growth and glucose metabolism of geese.

This experiment investigated the effects of different dietary starch sources on the growth and glucose metabolism of geese. A total of 240 healthy 35-day-old male geese were selected and randomly divided into 4 groups, with 6 replicates per group and 10 geese per replicate. Four types of diets were prepared, with glutinous rice (rapidly-digestible starch), corn, indica rice and high amylose as their starch sources, and fed for 28 d. Results showed that after consuming different feeds, the blood glucose of geese first increased and then decreased, reaching its maximum value 0.5 h after feeding, and there were significant differences between the groups (P < 0.05). The body weight of the corn and indica rice group geese at 63 d was higher than that of the high amylose group (P < 0.05). The serum total cholesterol (TCHO) content in the glutinous rice and corn groups was higher than in the high amylose group (P < 0.05). The serum insulin content in the glutinous rice group was lower than in the corn and high amylose groups (P < 0.05), while the glucagon content was higher (P < 0.05). The α-amylase activities of the pancreas, jejunal chyme, and jejunal mucosa in the glutinous rice group were higher than in the indica rice and high amylose groups (P < 0.05). The liver glycogen content in the glutinous rice group was higher than the other groups (P < 0.05). The liver glucose-6-phosphate dehydrogenase (G-6-PD) content in the glutinous rice group was higher than the high amylose group's (P < 0.05), but the glycogen synthase kinase-3 ß (GSK-3ß) content was lower (P < 0.05). In conclusion, the corn and indica rice diets had a positive effect on the growth performance of the geese, while the high amylose diet had a negative effect. The glutinous rice diet leads to rapid release of glucose, strengthening glucose metabolism pathways such as glycogen synthesis and the pentose phosphate pathway, and further influencing lipid metabolism.

[Summary and analysis of total auricle reconstruction in adult microtia patients].

Objective: To observe the clinical effect of auricle reconstruction in adult patients with microtia and summarize the experience. Methods: Clinical data of adult patients with microtia who underwent total auricle reconstruction using the modified Nagata's two stage for microtia reconstruction from June 2016 to June 2021 were analyzed. A total of 41 adult patients (42 ears) with microtia were enrolled, including 30 males and 11 females, with the median age at the time of surgery of 37 years. Autogenous costal cartilage was used as the auricular framework for all patients in this group. The first stage surgery was performed according to the modified Nagata's two stage for microtia reconstruction procedure,cartilage auricular framework carving was performed by different methods according to the ossification state of adult costal cartilage. Six months following the primary operation, ear elevation and cranioauricular angle formation, retroauricular facial flap transfer and medium-thick skin grafting were performed in the second stage. Results: All patients successfully completed two stage operation. During the follow-up of 3 months and 24 months, all the 41 patients were satisfied with the morphology of reconstructed auricle. Conclusion: According to the costal cartilage status of adult patients, different costal cartilage carving techniques can be used for total auricle reconstruction to obtain ideal surgical results.

Retraction Note: Knockdown of long non-coding RNA LUCAT1 reverses high glucose-induced cardiomyocyte injury via targeting CYP11B2.

The article "Knockdown of long non-coding RNA LUCAT1 reverses high glucose-induced cardiomyocyte injury via targeting CYP11B2, by Y. Yin, Z.-F. Yang, X.-H. Li, L.-Q. Zhou, Y.-J. Zhang, B. Yang, published in Eur Rev Med Pharmacol Sci 2019; 23 (19): 8560-8565-DOI: 10.26355/eurrev_201910_19171-PMID: 31646588" has been retracted by the authors as they cannot ensure the reproducibility of the data. The third party who provided some data turned out to be unreliable. The same manuscript was also questioned on PubPeer after publication. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/19171.

[Intravenous infusion of methylene blue to visualize the ureter in laparoscopic colorectal surgery].

Objective: Intraoperative localization of the ureter can contribute to accurate dissection and minimize ureteral injury in colorectal surgery. We aim to summarize a single center's experience of fluorescence ureteral visualization using methylene blue (MB) and explore its visualization efficiency. Methods: This is a descriptive case-series-study. Clinical data of patients who had undergone laparoscopic colorectal surgery and fluorescence visualization of the ureter in the Gastrointestinal Surgery Department of Guangdong Provincial People's Hospital from March 2022 to May 2022 were retrospectively collected. Patients with incomplete surgery videos, renal insufficiency, or allergic reactions were excluded. MB was infused with 0.9% NaCl at 1.0 mg/kg in 100 mL of normal saline for 5 to 15 minutes during laparoscopic exploration. Imaging was performed using a device developed in-house by OptoMedic (Guangdong, China) that operates at 660nm to achieve excitation of MB. Clinical information, MB dosage, rate of successful fluorescence, time to fluorescence, operation time, blood loss, intraoperative blood oxygen levels, pathological staging, changes in renal function, and post-operative complications were retrospectively analyzed. Results: The study cohort comprised 27 patients (24 men and 3 women) with an average age of (60.25±16.95) years and an average body mass index of (21.72±3.42) kg/m2. The dosage of MB was 0.3-1.0 mg/kg and the infusion time was 5-15 minutes. Fluorescence signals were detected in all patients. The median time to signal detection was 20 (range, 10 to 40) minutes after MB infusion. The range of intraoperative blood oxygen fluctuation averaged 2.5% (range, 0 to 7.0%). The median change in creatine concentration was -1.3 (range, -17.2 to 29.2) µmol/L. No patients had complications associated with use of MB. Fluorescence visualization of the ureter was very valuable clinically in two patients (thick mesentery, stage T4). Conclusion: MB is a safe and effective means of visualizing the ureter by fluorescence during laparoscopic colorectal surgery, especially when the procedure is difficult. MB in a dosage of less than 1 mg/kg can slowly infused for more than 5 minutes during laparoscopic exploration. During the infusion, attention must be paid to blood oxygen fluctuations.

Emergy evaluation and economic analysis of three wetland fish farming systems in Nansi Lake area, China.

Emergy and economic methods were used to evaluate and compare three fish production models, i.e., cage fish farming system, pond intensive fish rearing system and semi-natural extensive pond fish rearing system, in Nansi Lake area in China in the year 2007. The goal of this study was to understand the benefits and driving forces of selected fish production models from ecological and economic points of view. The study considered input structure, production efficiency, environmental impacts, economic viability and sustainability. Results show that the main difference among the three production systems was the emergy cost for fish feed associated with their feeding system, i.e., feeding on natural biomass such as plankton and grass or on commercial feedstock. As indicated by EYR, ELR and ESI, it can be clearly shown that the intensive production model with commercial feed is not a sustainable pattern. However, the point is that more environmentally sound patterns do not seem able to provide a competitive net profit in the short run. The intensive pond fish farming system had a net profit of 2.57E+03 $/ha, much higher than 1.27E+03 $/ha for cage fish farming system and slightly higher than 2.37E+03 $/ha for semi-natural fish farming system. With regard to the drivers of local farmer's decisions, the accessibility of land for the required use and investment ability determine the farmer's choice of the production model and the scale of operation, while other factors seem to have little effect. Theoretically, the development of environmentally sustainable production patterns, namely water and land conservation measures, greener feed as well as low waste systems is urgently needed, to keep production activities within the carrying capacity of ecosystems. Coupled emergy and economic analyses can provide better insight into the environmental and economic benefits of fish production systems and help solve the problems encountered during policy making.

A two-stage inexact joint-probabilistic programming method for air quality management under uncertainty.

A two-stage inexact joint-probabilistic programming (TIJP) method is developed for planning a regional air quality management system with multiple pollutants and multiple sources. The TIJP method incorporates the techniques of two-stage stochastic programming, joint-probabilistic constraint programming and interval mathematical programming, where uncertainties expressed as probability distributions and interval values can be addressed. Moreover, it can not only examine the risk of violating joint-probability constraints, but also account for economic penalties as corrective measures against any infeasibility. The developed TIJP method is applied to a case study of a regional air pollution control problem, where the air quality index (AQI) is introduced for evaluation of the integrated air quality management system associated with multiple pollutants. The joint-probability exists in the environmental constraints for AQI, such that individual probabilistic constraints for each pollutant can be efficiently incorporated within the TIJP model. The results indicate that useful solutions for air quality management practices have been generated; they can help decision makers to identify desired pollution abatement strategies with minimized system cost and maximized environmental efficiency.

Integrated process control for recirculating cooling water treatment in the coal chemical industry.

This work focused on the integrated process of the recirculating cooling water (RCW) treatment to achieve approximate zero emission in the coal chemical industry. The benefits of fractional and comprehensive RCW treatment were quantified and qualified by using a water and mass balance approach. Limits of cycle of concentrations and some encountered bottlenecks were used to ascertain set target limits for different water sources. Makeup water was mixed with water produced from reverse osmosis (RO) in the proportion of 6:4, which notably reduced salts discharge. Side infiltration, which settled down suspended solids, can reduce energy consumption by over 40%. An automated on-line monitoring organic phosphorus inhibitor feed maintains the RCW system stability in comparison to the manual feed. Two-step electrosorb technology (EST) instead of an acid feed can lead cycle of concentration of water to reach 7.0. The wastewater from RO, EST and filter was transferred into a concentration treatment system where metallic ions were adsorbed by permanent magnetic materials. Separation of water and salts was completed by using a magnetic disc separator. Applying the integrated process in a coal chemical industry, a benefit of 1.60 million Yuan annually in 2 years was gained and approximate zero emission was achieved. Moreover, both technical and economic feasibility were demonstrated in detail.

Investigating the spatial-temporal variation of nitrogen cycling in an urban river in the North China Plain.

Urban rivers are essential in retaining nutrients, but little is known about nitrogen cycling in these rivers in semiarid areas. We measured chemical and isotopic compositions of ammonium (NH4(+)-N) and nitrate (NO3(-)-N) to investigate spatial-temporal variation of nitrogen cycling in the Fuhe River in the North China Plain. Nitrogen pollution in the river was mainly induced by extra NH4(+)-N inputs which come from the discharges of urban sewage and effluents of wastewater treatment plants in upstream. NH4(+)-N obtained from decomposing organic matter of sediments can diffuse into the overlying water. Intense nitrification then occurs at the terrestrial-aquatic interface. Due to less vegetation in spring and autumn, loss of NH4(+)-N is mainly caused by nitrification. In contrast, significant NH4(+)-N is absorbed by plants in summer. NO3(-)-N generated from nitrification can be denitrified during the study period. The highest NO3(-)-N loss (about 86.3%) was observed in summer. The contribution of NO3(-)-N loss due to denitrification is 44.6%. The remaining 55.4% is due to plant uptake. The results suggested that nitrogen cycling in the river is related to temperature and dry-wet cycles. And vegetation restoration along the river could benefit the incremental improvements to the aquatic ecosystem.

Neuroprotective effects of hydroxysafflor yellow A against excitotoxic neuronal death partially through down-regulation of NR2B-containing NMDA receptors.

Hydroxysafflor yellow A (HSYA) is a component of the flower Carthamus tinctorius L. that elicits neuroprotective effects in vivo and in vitro. The purpose of this study was to investigate pharmacological properties of HSYA on neurotoxicity of glutamate in primary cultured rat cortical neurons along with its possible mechanism of action. After challenge with N-methyl-d-aspartate (NMDA, 100 microM) for 30 min, loss of cell viability and excessive apoptotic cell death were observed in cultured cortical neurons. However, the excitotoxic neuronal death was attenuated markedly by HSYA treatment. Western blot analysis revealed that HSYA decreased expression of Bax and rescued the balance of pro-and anti-apoptotic proteins. In addition, HSYA significantly reversed up-regulation of NR2B-containing NMDA receptors by exposure to NMDA, while it did not affect the expression of NR2A-containing NMDA receptors. These finding suggest that HSYA protects cortical neurons, at least partially, from inhibiting the expression NR2B-containing NMDA receptors and by regulating Bcl-2 family.

Genetic polymorphisms of cytochrome P450 enzymes 2C9 and 2C19 in a healthy Mongolian population in China.

We examined the distribution of major allelic variants of CYP2C9 and CYP2C19 in the Mongolian population of China and compared it with that of other populations. The polymorphisms of CYP2C9 (including the CYP2C9*1, CYP2C9*2 and CYP2C9*3 alleles) and CYP2C19 (including the CYP2C19*1, CYP2C19*2 and CYP2C19*3 alleles) were analyzed in 280 healthy unrelated Chinese Mongolian subjects, using a PCR-RFLP assay. The frequencies of CYP2C9*1, *2 and *3 alleles were 0.97, 0.00 and 0.03, respectively. The frequencies of CYP2C19*1, *2 and *3 alleles were 0.72, 0.24 and 0.04, respectively. We did not find any differences in the allelic distribution of these two genes between age groups. However, the genotype frequency of CYP2C9 *1/*3 was significantly higher in males than in females. Compared with other populations, we found that the allele frequencies of the CYP2C9*2 and CYP2C9*3 allelic variants in this Mongolian population of China were similar to those reported for other Asian populations, with significant differences compared to Caucasians and African-Americans.

Occurrence of aliphatic hydrocarbons in water, suspended particulate matter and sediments of Daliao River system, China.

In August of 2005 a study was carried out to evaluate contamination of aliphatic hydrocarbons(AHc) in water, suspended particulate matter (SPM) and sediments from Daliao River system composed of the Hun River, Taizi River, and Daliao River in a heavy industrial area of northeast of China. The content of AHc ranged from 13.39 to 283.62 microg L(-1) in surface water, from 22.68 to 5,725.36 microg g(-1) in dry SPM, and from 61.37 to 229.42 microg g(-1) in dry sediments. High hydrocarbon levels were generally found in the areas associated with high anthropogenic impact and port activities. The calculated hydrocarbon indexes suggest that the stations with petrogenic sources and biogenic origin predominance would constitute aliphatic hydrocarbons for the river system. Hierarchical cluster analysis (HCA) of aliphatic hydrocarbons is correspondence with hydrocarbons indexes results.