[Mechanism of Inorganic Nitrogen Transformation and Identification of Nitrogen Sources in Water and Soil].

Nitrogen plays a vital role in biological activities as the basic element of organic molecules and the main nutrient of soil. In the study of nitrogen pollution, the first step is to understand the transformation mechanism of various nitrogen forms. Based on the transformation process and the mechanism of nitrogen in the ecosystem, this review summarizes the research methods of nitrogen source analysis and nitrogen isotope fractionation in soil and water, and categorically reviews the applications of nitrogen source identification in surface water and groundwater. We showed that it is more effective to identify the sources of soil and water nitrogen pollution by combining hydrochemical methods with the multi-isotope approach. The importance of primary nitrogen sources should also be quantified to study groundwater pollution. A new approach to determine the source of oxygen atoms during nitrosation was also presented, and the enrichment principle of δ18O-NO3- during secondary oxidation was explained. Finally, the contribution of primary ammonium nitrogen to groundwater pollution was discussed, and innovative research ideas were provided.

Upregulation of RND3 Affects Trophoblast Proliferation, Apoptosis, and Migration at the Maternal-Fetal Interface.

Trophoblasts as the particular cells of the placenta play an important role in implantation and formation of the maternal-fetal interface. RND3 (also known as RhoE) is a unique member of the Rnd subfamily of small GTP-binding proteins. However, its function in cytotrophoblasts (CTBs) at the maternal-fetal interface is poorly understood. In the present study, we found that RND3 expression was significantly increased in trophoblasts from the villous tissues of patients with recurrent miscarriage (RM). RND3 inhibited proliferation and migration and promoted apoptosis in HTR-8/SVneo cells. Using dual-luciferase reporter and chromatin immunoprecipitation assays, we found that forkhead box D3 (FOXD3) is a key transcription factor that binds to the RND3 core promoter region and regulates RND3 expression. Here, the level of FOXD3 was upregulated in the first-trimester CTBs of patients with RM, which in turn mediated RND3 function, including inhibition of cell proliferation and migration and promotion of apoptosis. Further, we found that RND3 regulates trophoblast migration and proliferation via the RhoA-ROCK1 signaling pathway and inhibits apoptosis via ERK1/2 signaling. Taken together, our findings suggest that RND3 and FOXD3 may be involved in pathogenesis of RM and may serve as potential therapeutic targets.

Ulcerative colitis complicated with colonic necrosis, septic shock and venous thromboembolism: A case report.

BACKGROUND: Severe total colonic necrosis, septic shock and venous thromboembolism secondary to ulcerative colitis (UC) are rare and life-threatening. No such severe complications have been reported in the literature. CASE SUMMARY: We report a 36-year-old woman who developed total colonic necrosis and septic shock secondary to UC. The patient was treated with emergency surgery because computed tomography showed suspicious perforations. Persistent massive ascites occurred after operation and computed tomography angiography demonstrated portal vein, mesenteric vein and splenic vein thrombosis. The patient was discharged from hospital after active treatment. CONCLUSION: Clinicians should pay attention to venous thrombosis, colonic necrosis and septic shock in UC patients. Close observation of surgical indications and timely surgical intervention are the key to reduce mortality and complications in UC.

LncRNA SLC8A1-AS1 protects against myocardial damage through activation of cGMP-PKG signaling pathway by inhibiting SLC8A1 in mice models of myocardial infarction.

Extensive investigations into long noncoding RNAs (lncRNAs) in various diseases and cancers, including acute myocardial infarction (AMI) have been conducted. The current study aimed to investigate the role of lncRNA solute carrier family 8 member A1 antisense RNA 1 (SLC8A1-AS1) in myocardial damage by targeting solute carrier family 8 member A1 (SLC8A1) via cyclic guanosine 3',5'-monophosphate-protein kinase G (cGMP-PKG) signaling pathway in AMI mouse models. Differentially expressed lncRNA in AMI were initially screened and target relationship between lncRNA SLC8A1-AS1 and SLC8A1 was then verified. Infarct size, levels of inflammatory factors, biochemical indicators, and the positive expression of the SLC8A1 protein in AMI were subsequently determined. The expression of SLC8A1-AS1, SLC8A1, PKG1, PKG2, atrial natriuretic peptide, and brain natriuretic peptide was detected to assess the effect of SLC8A1-AS1 on SLC8A1 and cGMP-PKG. The respective contents of superoxide dismutase, lactate dehydrogenase (LDH), and malondialdehyde (MDA) were detected accordingly. Microarray data GSE66360 provided evidence indicating that SLC8A1-AS1 was poorly expressed in AMI. SLC8A1 was verified to be a target gene of lncRNA SLC8A1-AS1. SLC8A1-AS1 upregulation decreased levels of left ventricular end-systolic diameter, -dp/ dt max , interleukin 1ß (IL-1ß), IL-6, transforming growth factor α, nitric oxide, inducible nitric-oxide synthase, endothelial nitric-oxide synthase, infarct size, LDH activity and MDA content, and increased IL-10, left ventricular end-diastolic pressure and + dp/ dt max . Furthermore, the overexpression of SLC8A1-AS1 was noted to elicit an inhibitory effect on the cGMP-PKG signaling pathway via SLC8A1. In conclusion, lncRNA SLC8A1-AS1, by downregulating SLC8A1 and activating the cGMP-PKG signaling pathway, was observed to alleviate myocardial damage, inhibit the release of proinflammatory factors and reduce infarct size, ultimately protecting against myocardial damage.

Tumour necrosis factor-α gene -308 G > A and -238 G > A polymorphisms are associated with susceptibility to irritable bowel syndrome and drug efficacy in children.

WHAT IS KNOWN AND OBJECTIVE: An imbalance in the genetically controlled pro- and anti-inflammatory cytokine production could potentially promote ongoing low-grade inflammation following an episode of acute gastroenteritis and, subsequently, could result in irritable bowel syndrome (IBS; post-infectious IBS, PI-IBS). Since there is very little known on the impact of pro-inflammatory cytokines such as tumour necrosis factor-α (TNF-α) on IBS, we conducted the present study with aims of determining the correlation between TNF-α gene polymorphisms (-308 G > A and -238 G > A) and susceptibility to IBS and drug efficacy in children. METHODS: Diarrhoea-predominant IBS patients and healthy subjects were recruited for DNA extraction. The genotypes were tested using polymerase chain reaction-restriction fragment length polymorphism. In addition to conventional symptomatic treatments, Live Combined Bifidobacterium, Lactobacillus and Enterococcus Powder and Montmorillonite Powder were administered to all the patients participating in the study for consecutive 4 weeks. The efficacy was evaluated 2 weeks after the withdrawal of the drugs. The association between gene polymorphism and drug efficacy was analysed by means of binary logistic regression analysis. RESULTS: Patients in the IBS group were susceptible to IBS with GA genotype and A allele of -308 G > A so were those with AA genotype and A allele of -238 G > A. The symptoms were also alleviated following treatment. The cure rate of patients with GA genotype of -308 G > A and AA genotype of -238 G > A was low. These findings suggested that the haplotype AA could potentially be associated with the cure rate of IBS patients. GA genotype of -308 G > A, AA genotype of -238 G > A, enterobacteria and 5-hydroxytryptamine in serum may act adversely, whereas bifidobacterial may be beneficial to the efficacy of IBS treatment. WHAT IS NEW AND CONCLUSION: The above findings evidently suggest that the frequency of TNF-α gene -308 G > A carrying GA genotype and A allele and -238 G > A carrying AA genotype and A allele is higher in children with IBS. Additionally, GA genotype of -308 G > A and AA genotype of -238 G > A may act adversely to the efficacy of IBS treatment, which may be a reference index for predicting the curative effect of IBS.

Effects of MicroRNA-592-5p on Hippocampal Neuron Injury Following Hypoxic-Ischemic Brain Damage in Neonatal Mice - Involvement of PGD2/DP and PTGDR.

BACKGROUND/AIMS: This study aimed to explore the effect of microRNA-592-5p (miR-592-5p) on hypoxic-ischemic brain damage (HIBD)-induced hippocampal neuronal injury in a neonatal mouse model relative to the involvement of one target gene, PTGDR, and the PGD2/ DP signaling pathway. METHODS: A total of 30 neonatal mice aged 7 days were randomly selected to establish an HIBD mouse model. Hippocampal neuronal cells were transfected into a control group, a blank group, a negative control (NC) group, an miR-592-5p mimics group, an miR-592-5p inhibitors group, an siRNA-PTGDR group and an miR-592-5p inhibitors + siRNA-PTGDR group. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot analyses were performed to detect the expression levels of miR-592-5p, PTGDR, DP2, Bcl-2 and Bax in tissues and cells. Cell proliferation, cell cycle and apoptosis were detected by MTT assay and flow cytometry, respectively. RESULTS: The expression levels of miR-592-5p and Bcl-2 decreased, while the expression levels of PTGDR, DP2 and Bax increased in the HIBD group. PTGDR is a target gene of miR-592-2p. Compared with the NC and blank groups, the expression levels of PTGDR, DP2 and Bax decreased, while the expression levels of miR-592-5p and Bcl-2 increased in the miR-592-5p mimics group. The siRNA-PTGDR group showed the same trend as that observed in the miR-592-5p mimics group, except with no difference in miR-592-5p expression. The miR-592-5p inhibitors group showed an opposite gene expression trend compared to that in the miR-592-5p mimics group. The S phase of the cell cycle was prolonged, the G1 phase was reduced, proliferation was increased, and the apoptosis rate was decreased in the siRNA-PTGDR and miR-592-5p mimics groups. Opposite trends for cell cycle, proliferation and apoptosis were observed in the miR-592-5p inhibitors group. CONCLUSIONS: Our study suggests that miR-592-5p upregulation protects against hippocampal neuronal injury caused by HIBD by targeting PTGDR and inhibiting the PGD2/DP signaling pathway.

Elevated serum levels of ghrelin and TNF-α in patients with cyanotic and acyanotic congenital heart disease.

BACKGROUND: The levels of ghrelin and tumor necrosis factor alpha (TNF-α) are considered biological markers of congenital heart diseases (CHD). The present meta-analysis was conducted to investigate the clinical significance of serum levels of ghrelin and TNF-α in children with (CHD). METHODS: Chinese and English scientific literature databases were searched to retrieve published studies relevant to ghrelin, TNF-α and CHD. Manual search was additionally employed to identify other relevant studies from cross-references. The retrieved studies were screened on the basis of our stringent inclusion and exclusion criteria to select high quality case-control studies for meta-analysis. RESULTS: We initially retrieved 108 published studies (20 in Chinese and 88 in English) from database searches. Finally, 6 case-control studies (5 in English and 1 in Chinese) were enrolled in our meta-analysis, and contained a total of 160 cyanotic congenital heart disease (CCHD) patients and 215 acyanotic congenital heart disease (ACHD) patients, along with 162 healthy controls. The results of meta-analysis showed that serum levels of ghrelin and TNF-α in CCHD or ACHD children were significantly higher than those in healthy controls. CONCLUSIONS: Our meta-analysis results showed that serum levels of ghrelin and TNF-α are elevated in children with CHD, and could be used as effective biologic markers in early diagnosis of CHD.

Electro-optical equivalent calibration technology for high-energy laser energy meters.

Electro-optical equivalent calibration with high calibration power and high equivalence is particularly well-suited to the calibration of high-energy laser energy meters. A large amount of energy is reserved during this process, however, which continues to radiate after power-off. This study measured the radiation efficiency of a halogen tungsten lamp during power-on and after power-off in order to calculate the total energy irradiated by a lamp until the high-energy laser energy meter reaches thermal equilibrium. A calibration system was designed based on the measurement results, and the calibration equivalence of the system was analyzed in detail. Results show that measurement precision is significantly affected by the absorption factor of the absorption chamber and by heat loss in the energy meter. Calibration precision is successfully improved by enhancing the equivalent power and reducing power-on time. The electro-optical equivalent calibration system, measurement uncertainty of which was evaluated as 2.4% (k = 2), was used to calibrate a graphite-cone-absorption-cavity absolute energy meter, yielding a calibration coefficient of 1.009 and measurement uncertainty of 3.5% (k = 2). A water-absorption-type high-energy laser energy meter with measurement uncertainty of 4.8% (k = 2) was considered the reference standard, and compared to the energy meter calibrated in this study, yielded a correction factor of 0.995 (standard deviation of 1.4%).

The complete mitochondrial genome of Leizhou goat Capra hircus (Bovidae; Caprinae).

Leizhou goat (Capra hircus) is one of the famous native goat breed in China. In this study, the 16,651 bp complete nucleotide sequence of Leizhou goat mitochondrial genome was sequenced for the first time. It contained 22 tRNA genes, 2 ribosomal RNA genes, 13 protein-coding genes.

Toxic effects of ionic liquid 1-octyl-3-methylimidazolium bromide on the antioxidant defense system of freshwater planarian, Dugesia japonica.

The activities of antioxidant enzymes and the levels of glutathione (GSH) and malondialdehyde (MDA) were determined when freshwater planarian Dugesia japonica was exposed to different concentrations of 1-octyl-3-methylimidazolium bromide ([C8mim]Br) for one, three, and five days. The results showed that superoxide dismutase (SOD) activity began to increase in all treated groups after three days of exposure, while catalase (CAT) activity was inhibited after the first day, but increased notably on the fifth day except for the lowest concentration group. The activity of glutathione peroxidase (GPX) was induced from the first day of exposure and increased significantly after five days in all treated groups. During the experiment, the levels of intracellular GSH in all treated groups were higher than that of the control group. Changes in MDA suggest that [C8mim]Br is toxic to D japonica and may result in lipid peroxidation in planarian. Our results also indicate that GPX as well as GSH seem to be more sensitive biomarkers of oxidative stress compared with SOD and CAT.

Technology for radiation efficiency measurement of high-power halogen tungsten lamp used in calibration of high-energy laser energy meter.

The calibration method using a high-power halogen tungsten lamp as a calibration source has many advantages such as strong equivalence and high power, so it is very fit for the calibration of high-energy laser energy meters. However, high-power halogen tungsten lamps after power-off still reserve much residual energy and continually radiate energy, which is difficult to be measured. Two measuring systems were found to solve the problems. One system is composed of an integrating sphere and two optical spectrometers, which can accurately characterize the radiative spectra and power-time variation of the halogen tungsten lamp. This measuring system was then calibrated using a normal halogen tungsten lamp made of the same material as the high-power halogen tungsten lamp. In this way, the radiation efficiency of the halogen tungsten lamp after power-off can be quantitatively measured. In the other measuring system, a wide-spectrum power meter was installed far away from the halogen tungsten lamp; thus, the lamp can be regarded as a point light source. The radiation efficiency of residual energy from the halogen tungsten lamp was computed on the basis of geometrical relations. The results show that the halogen tungsten lamp's radiation efficiency was improved with power-on time but did not change under constant power-on time/energy. All the tested halogen tungsten lamps reached 89.3% of radiation efficiency at 50 s after power-on. After power-off, the residual energy in the halogen tungsten lamp gradually dropped to less than 10% of the initial radiation power, and the radiation efficiency changed with time. The final total radiation energy was decided by the halogen tungsten lamp's radiation efficiency, the radiation efficiency of residual energy, and the total power consumption. The measuring uncertainty of total radiation energy was 2.4% (here, the confidence factor is two).

Cardioprotective Effect of MicroRNA-21 in Murine Myocardial Infarction.

INTRODUCTION: To investigate the cardioprotective effect of MicroRNA-21 (miR-21) in murine myocardial infarction (MI). METHODS: Forty C57BL/6 male mice were divided into sham group, MI group, LV-GFP group, and miR-21 group. Mice in the MI group, LV-GFP group, and miR-21 group were subjected to MI by left anterior descending artery (LAD) ligation, while chest was opened/closed without ligation in sham group. In MI group, expression of miR-21 in the MI area and its surrounding areas was detected at 1st, 2nd, and 4th week after experiment. Subsequently, lentivirus expressing miR-21 and lentivirus that did not express miR-21 were transfected into mice left ventricular cavity of miR-21 group and LV-GFP group, respectively. Cardiac function, MI size, miR-21 expression, collagen I level, fibronectin content, number of α-SMA-positive cells, number of apoptotic cells, apoptosis-related factors were compared between the three groups. RESULTS: Compared with sham group, miR-21 levels in MI group were significantly decreased in the 1st week and 2nd week, but were almost the same in the 4th week. Left ventricular fractional shortening (LVFS) and left ventricular ejection fraction (LVEF) in the miR-21 group improved compared to the LV-GFP group. In miR-21 group, myocardial infarct size reduced by 36.9% in comparison with LV-GFP group. Compared to sham group, miR-21 expression in the miR-21 group and LV-GFP group decreased significantly. In the miR-21 group, collagen I level, fibronectin content and number of α-SMA-positive cells of miR-21 decreased significantly compared to the LV-GFP group. The number of apoptotic cells in the MI areas of the miR-21 group was significantly less than the LV-GFP group. Compared with the LV-GFP group, Bcl-2 level and the ratio of Bcl-2 to Bax were significantly increased, and the levels of Bax and Caspase-3 decreased. CONCLUSIONS: Our results suggest miR-21 is an important regulatory molecule in the pathophysiology of MI.

Research on temperature measurement technology for graphite-cone-absorption-cavity absolute calorimeter.

The nonlinear effect of materials and sensors in high-energy laser calorimeters is especially obvious-due to the steep temperature gradients of their absorbers. Significant measurement errors occur when traditional integral temperature sensors and methods are utilized. In an effort to remedy this, a method is proposed in this paper in which an absorption cavity is divided into many parts and multiple discrete thermocouple sensors are used to measure the temperature rise of the absorbers. The temperature distribution in the absorbers is theoretically analyzed, numerically simulated, and verified through experimentation. Energy measurement results are compared according to the temperature distribution for different layouts of thermocouples. A high-accuracy calorimeter is developed by setting and optimizing thermocouple layout, as well as correcting various elements such as the specific heat of graphite and responsivity of thermocouples. The calorimeter employing this measurement method is calibrated against a standard energy meter, resulting in correction coefficient of 1.027 and relative standard deviation of the correction coefficient of only 0.8%. Theoretical analysis, numerical simulation, and experimental verification all prove that the proposed method successfully improves measurement accuracy.

[Simulated study of algal fatty acid degradation in hypoxia seawater-sediment interface along China coastal area].

Series of laboratory incubation experiments were conducted to simulate degradation of organic matter in sediment-seawater interface in hypoxia enviroments along China coastal area. Under four different redox conditions (oxygen saturation: 100%, 50%, 25% and 0%), degradations of seveal biomarkers originated from Skeletonema costatum, a typical red tide alage along China coastal area were tracked. By analyzing concentrations of four fatty acid biomarkers [14:0, 16:0, 16:1(7) and 20:5] obtained at various sampling time, results showed that their concentrations decreased significantly after 2-3 weeks' incubation. Then, their concentrations changed very slowly or very little. However, degradation of the four fatty acids varied dramatically in different incubation systems. Fatty acids 14:0, 16:1(7) and 20:5 were degraded completely in all incubation systems after two-month incubation, but 25% to 35% of 16:0 was reserved in the systems. Based on multi-G model, degradations of the four fatty acids were quantively described. The results indicated that all four fatty acids had fast-degraded and slow-degraded fractions. Their degradation rate constants (k(av)) ranged from 0.079 to 0.84 d(-1). The fastest degradation of 14:0 and 16:1 (7) occurred under 25% oxygen concentrations. For these two compounds, in the fastest degradation system, their k(av), values were 2.3 folds and 1.7 folds higher than those in the slowest degradation system [50% oxygen saturation for 14:0 and 100% oxygen saturation for 16:1(7)] respectively. The 16:0 was degraded fastest under the anoxic condition and slowest under the 50% oxygen saturation. The ratio of the two k(av)s was 2.1. The k(av)s of 20:5 had a positive relationship with oxygen saturations. Results of this study suggested that besides oxgen saturations, structure and features of organic compounds, roles of microbe in the envrioments and etc. might affect degradations of fatty acids in S. costatum in hypoxia sediment-seawater interface along China coastal area.

[Depth selectivity by using polarization-controlled spectral technique].

A continuous depth selectivity is examined by changing the state of polarization of the signal light, based on the orthogonal polarization spectral (OPS) microcirculation imaging system. Unlike the traditional OPS system, which could only rend a two dimensional image of a certain cross-section, the elliptically polarized light controlled by the polarizer unit and the analyzer unit could do the microscopy refocusing without mechanically scanning the sample, as a result, the tissue information at different depths could be obtained. Because the proposed system matches the emission spectrum of the light source with the absorption spectrum of the erythrocyte, it has relatively high signal-to-noise ratio, and could be used to detect microcirculation. Imaging of a pork fat with a target is acquired, and the quantitative relationship between image contrast and the state of polarization is illustrated. The results show that from linearly to circularly polarized illumination, the image contrast gradually increases, and the maximum visible depth also increases. Finally, the auricle vessel of a nude mouse was detected by this polarization-controlled spectral imaging system. Through the experiment the feasibility of depth selectivity was proved. The proposed method provides new insights to microscopy refocusing of microcirculation.

Modified physiological and operative score for the enumeration of mortality and morbidity risk assessment model in general surgery.

AIM: To establish a scoring system for predicting the incidence of postoperative complications and mortality in general surgery based on the physiological and operative severity score for the enumeration of mortality and morbidity (POSSUM), and to evaluate its efficacy. METHODS: Eighty-four patients with postoperative complications or death and 172 patients without postoperative complications, who underwent surgery in our department during the previous 2 years, were retrospectively analyzed by logistic regression. Fifteen indexes were investigated including age, cardiovascular function, respiratory function, blood test results, endocrine function, central nervous system function, hepatic function, renal function, nutritional status, extent of operative trauma, and course of anesthesia. Modified POSSUM (M-POSSUM) was developed using significant risk factors with its efficacy evaluated. RESULTS: The significant risk factors were found to be age, cardiovascular function, respiratory function, hepatic function, renal function, blood test results, endocrine function, nutritional status, duration of operation, intraoperative blood loss, and course of anesthesia. These factors were all included in the scoring system. There were significant differences in the scores between the patients with and without postoperative complications, between the patients died and survived with complications, and between the patients died and survived without complications. The receiver operating characteristic curves showed that the M-POSSUM could accurately predict postoperative complications and mortality. CONCLUSION: M-POSSUM correlates well with postoperative complications and mortality, and is more accurate than POSSUM.

[A study on individual mandibular prostheses according to 3D reconstruction of CT images and CNC simulation method].

The new method of manufacturing individual mandibular prostheses, in combination with CT data and CNC technique, can duplicate bone tissues accurately, and can have the individual mandibular prosthesis made to order, and repair the mandibular defect (especially the lager mandibular segmental defect).