[Temporal and Spatial Variation Characteristics of Methane, Carbon Dioxide, and Nitrous Oxide Concentrations and the Influencing Factors in Small Aquaculture Pond].

As an important source of greenhouse gases, the changes in greenhouse gas concentrations of aquaculture ponds are not only the basis for accurate quantification of greenhouse gases emissions but are also important for identifying their influencing factors. The spatial and temporal variation characteristics of CH4, CO2, and N2O concentrations and the influencing factors in a typical small aquaculture pond in the Yangtze River Delta were analyzed based on the headspace equilibrium-gas chromatograph method. Except in spring, the concentrations of CH4, and N2O appeared high at noon or afternoon and were influenced by water temperature. Impacted by water temperature and aquatic plant photosynthesis, the concentrations of CO2 were high in the morning when photosynthesis was weak. The concentrations of CH4 and CO2 were the highest in autumn and the lowest in winter. The mean concentrations of CH4 in autumn and winter were 176.34 nmol·L-1 and 32.75 nmol·L-1, respectively, which were mainly affected by air temperature, water temperature, and dissolved oxygen. The average CO2 concentrations in autumn and winter were 134.37 µmol·L-1 and 23.10 µmol·L-1, respectively, and were mainly affected by aquatic vegetation photosynthesis and pH. N2O concentration was the highest in summer and the lowest in winter, with mean values of 97.05 nmol·L-1 and 19.41 nmol·L-1, respectively, which were mainly affected by air temperature and water temperature. In terms of the vertical spatial variations of the three greenhouse gases, the concentration of CH4decreased with water depth in summer, and the concentration differences between the surface layer and the bottom and middle layers were 71.28 nmol·L-1 and 42.80 nmol·L-1, respectively. The concentration of CH4 increased with water depth in autumn, and the concentration difference between the bottom layer and surface layer was 163.94 nmol·L-1. The CO2 concentration increased with water depth in summer and autumn. The concentration differences between the bottom and surface concentrations were 18.69 µmol·L-1 and 29.90 µmol·L-1, respectively. N2O concentration showed no obvious change in the vertical direction. For the horizontal variations, the concentrations of CH4, CO2, and N2O in the feeding area in summer and in chicken manure in spring were approximately 1.34-1.98 times and 1.95-2.42 times those in other areas, respectively, and the concentrations of N2O and CO2 in spring and summer were approximately 1.13-1.26 times and 1.39-1.74 times those in other areas.

[Effects of chamber characteristics on CO2 and CH4 flux at the water-air interface measured by the chamber method]. / 箱体特征对箱式法观测水-气界面CO2和CH4通量的影响.

The chamber method is widely used to measure CO2 and CH4 flux in inland water. However, the designs of chamber used in various studies are different and lack unified standards, which would affect the observation results. To clarify the impacts of chamber characteristics, including light transmittance, air pressure difference inside and outside the chamber, and gas mixing degree in the chamber, on CO2 and CH4 flux measurements at the water-air interface, we compared the effects of transparent/opaque chamber, the chamber with/without air pressure equalizing device and fan on CO2 and CH4 flux measurements in the aquaculture pond, based on the multi-channel closed dynamic chamber system. The results showed that, during the daytime in summer, compared with the transparent chamber which could measure the actual CO2 flux, when CO2 was emitted from the pond, the opaque chamber overestimated the CO2 flux by 90%; when CO2 was absorbed by the pond, the opaque chamber underestimated the CO2 flux by 50%. The CH4 diffusion flux measured by the opaque chamber was 40% lower than that measured by the transparent chamber. There was no significant difference between CO2 and CH4 flux measured by the chamber with and without air pressure equalizing device. CO2 flux observed by the chamber without fan had poor representativeness, being 20% higher than that observed by the chamber with fan. Moreover, CH4 flux emitted through different pathways could not be distinguished using the chamber without fan. Therefore, when the chamber method was used to observe the CO2 and CH4 flux at the water-air interface, the chamber shall be transparent and be installed with fan.

Imbalance of T-helper 1/T-helper 2 cytokines and impaired glucose tolerance among patient with acute coronary syndrome.

PURPOSE: The balance between T helper (Th) cells Th1- and Th2-related cytokines plays a key role in the clinical process of acute coronary syndrome (ACS) and type 2 diabetes mellitus (T2DM) or impaired glucose tolerance (IGT). The objective of this study was to assess the status of Th1/Th2 cytokines in patients with ACS and T2D or IGT. METHODS: A total of 201 ACS patients were enrolled in the study. All ACS patients were divided into three groups: Group I-patients with normal glucose tolerance (NGT), Group II-patients with IGT and Group III-patients with T2D. We measured circulating Th1/Th2-type cytokines (interleukin [IL]-4, IL-13, interferon-gamma [IFN-γ], and tumor-necrosis factor-alpha [TNF-α]) using enzyme-linked immunosorbent assay and calculated the ratio of Th1/Th2. RESULTS: Significant elevations in serum levels of IL-4, IL-13, IFN-γ, and TNF-α were found in ACS-T2D and ACS-IGT groups compared to that in both ACS-NGT group and healthy individuals. Higher serum levels of IL-4, IL-13, and TNF-α were found in ACS-NGT group than that in the control group. Furthermore, IL-4 and IFN-γ concentrations were significantly higher in ACS-T2D patients than in ACS-IGT patients. IFN-γ/IL-4, IFN-γ/IL-13, and TNF-α/IL-4 ratios as markers of Th1/Th2 ratio were significantly higher for the ACS-T2D group and ACS-IGT group as compared to that in the ACS-NGT group and control group (P < 0.05). CONCLUSION: Shifts in the balance of Th1/Th2 toward a predominance of Th1 may represent more severe inflammatory status in ACS patients with type T2D or IGT.

[Quantification of Methane Ebullition Flux from Small Ponds Using the Inverted-Funnel Method].

To quantify the ratio of CH4 ebullition to total flux in subtropical shallow ponds, the CH4 flux at the water-air interface was measured using the inverted-funnel and water equilibrium methods in two small ponds in Quanjiao, Anhui Province from July 28 to August 13, 2016. The average CH4 ebullition fluxes were 121.78 and 161.08 mg·(m2·d)-1 and the average diffusion fluxes were 3.38 and 3.79 mg·(m2·d)-1 over pond A and pond B, respectively. The ebullition flux accounted for 97.5% and 96.4% of the total flux over pond A and pond B, respectively. Methane ebullition ranged from 0.11 to 446.90 mg·(m2·d)-1 over pond A and from 0.05 to 607.51 mg·(m2·d)-1 over pond B. Gas ebullition rate during the day was higher than that at night and was controlled by wind speed. Methane ebullition flux was influenced by wind speed over the shallow pond at hourly scale and by water depth and wind speed at daily scale, with positive correlation with wind speed and negative correlation with water depth. Varying with latitude, methane ebullition flux was higher for the water bodies in the mid-latitude region compared to those in the high-latitude region. Direct observations of the methane ebullition flux over small ponds provide data support and theoretical reference to precisely estimate the contribution of inland water bodies to regional and global carbon cycle.

[CH4 Emissions Characteristics and Its Influencing Factors in an Eutrophic Lake].

In order to identify methane (CH4) diffusion emissions characteristics and their impact factors in an eutrophic lake, CH4 flux across the lake-air interface was observed in Meiliang Bay and the central zone of Lake Taihu over one year. The relationships between CH4 flux and environmental factors and water quality indices were analyzed. The results indicated that the annual mean CH4 diffusion flux in the eutrophic zone was significantly higher than that in the central zone, which were 0.140 mmol·(m2·d)-1 and 0.024 mmol·(m2·d)-1, respectively. Additionally, the highest CH4 flux appeared in the eutrophic littoral zone. The CH4 flux varied seasonally, which was consistent with water temperature that peaked in summer. Furthermore, the difference in CH4 flux between seasons was an order of magnitude. The temporal variation in CH4 flux was mostly driven by wind speed and water temperature. The spatial correlation between CH4 flux and dissolved organic carbon concentration was highly significant (R2=0.62, P<0.01). Observing temporal and spatial patterns of CH4 flux was necessary to accurately estimate whole-lake CH4 emissions due to large variability across time and space.

Assessment of liver fibrosis using T1 mapping on Gd-EOB-DTPA-enhanced magnetic resonance.

BACKGROUND: Few studies have investigated the value of Gd-EOB-DTPA-enhanced T1 mapping in exact fibrosis staging, especially its correlation with hepatic molecular transporters. AIMS: To investigate the diagnostic value of Gd-EOB-DTPA-enhanced T1 mapping in staging liver fibrosis and its relationship with hepatic molecular transporters. METHODS: Thirty rats were divided into the carbon tetrachloride-induced fibrosis groups and a control group. T1-mapping was performed before and 20min after administration of Gd-EOB-DTPA. The T1 relaxation time and reduction rate (Δ%) were calculated, and their correlations with the degree of fibrosis, necroinflammatory activity, iron load and hepatic molecular transporters were assessed and compared. RESULTS: Hepatobiliary phase T1 relaxation time (HBP) and Δ% were different between each adjacent fibrosis subgroups(P=0.000-0.042). Very strong correlations existed between fibrosis and both HBP and Δ% (r=0.960/-0.952), and multivariate analyses revealed that fibrosis was the only factor independently predicted by HBP (P=0.000) and Δ% (P=0.001), comparing to necroinflammatory activity and iron load. The expression of the organic anion transporting polypeptide1a1 (Oatp1a1) was significantly correlated with HBP and Δ% at both mRNA (r=-0.741/0.697) and protein (r=-0.577/0.602) levels. Weaker correlations were found for multidrug resistance associated protein2 (Mrp2). Generally, both transporters showed decreasing levels with increasing degrees of fibrosis. CONCLUSION: Gd-EOB-DTPA-enhanced T1 mapping may provide a reliable diagnostic tool in staging liver fibrosis, and can be regarded as a useful imaging biomarker of hepatocyte transporter function.

Diffusion kurtosis imaging and diffusion-weighted imaging in assessment of liver fibrosis stage and necroinflammatory activity.

PURPOSE: To investigate and compare the diagnostic value of diffusion kurtosis imaging (DKI) with diffusion-weighted imaging (DWI) in assessing and quantifying hepatic fibrosis. METHODS: Thirty rats were divided into the control group (n = 6) and the fibrosis experimental groups (n = 6 per group) with CCl4 administration for 2, 4, 6, and 8 weeks. Liver fibrosis stage (S) and necroinflammatory activity grade (G) were histopathologically determined. DKI and DWI were performed; mean apparent diffusion (MD), mean kurtosis (MK), and apparent diffusion coefficient (ADC) values were calculated. DKI parameters were compared with ADC values according to G/S scores. RESULTS: Strong inverse correlations were found between the degree of fibrosis and both MD and ADC (r = -0.840 and r = -0.760), while only weak correlation existed in MK (r = 0.405). ROC analyses demonstrated the AUC in MD, MK, and ADC of 0.862, 0.684, 0.817 for identifying mild and severe fibrosis, and 0.757, 0.675, 0.733 for non-cirrhosis and cirrhosis, respectively. The degree of fibrosis was significantly correlated with α-smooth muscle actin (α-SMA) (P < 0.0001); α-SMA had strong inverse correlation with MD (r = -0.723), moderate inverse correlation with ADC (r = -0.613), and very weak correlation with MK (r = 0.175). Additionally, MD was strongly correlated with the necroinflammatory activity (r = -0.758), ADC was moderately correlated (r = -0.492), and MK was weakly correlated (r = 0.254). CONCLUSION: DKI may provide added information and serve as a valuable tool for the characterization and surveillance of liver fibrosis in a non-invasive manner.

MR comparative study of combined hepatocellular-cholangiocarcinoma in normal, fibrotic, and cirrhotic livers.

PURPOSE: To compare MR imaging features of combined hepatocellular-cholangiocarcinoma (cHCC-CC) in normal, fibrotic, and cirrhotic livers. METHODS: A total of 64 patients with 67 pathologically proven cHCC-CCs were retrospectively analyzed. Patients were classified into three groups according to the patients' liver condition: patients with normal liver (F0, group 1), fibrosis without cirrhosis (F1-3, group 2), and cirrhosis (F4, group 3). The morphological and MR signal features on T1- and T2-weighted, dynamic contrast-enhanced, diffusion-weighted imaging, as well as the accompanying imaging findings, were evaluated and compared. RESULTS: There were 12, 19, and 33 patients in groups 1, 2, and 3, respectively. Tumors in the fibrotic and cirrhotic livers were smaller than those in the normal liver, and tumors with cirrhosis had the smallest size (P = 0.0326). No statistical difference was found when comparing the signal intensity on T2-weighted imaging (P = 0.496), but iso- or hypointense lesions were only found in the fibrosis (n = 2) or cirrhosis group (n = 2). Enhancement pattern was different between groups, the washout pattern was more often seen in the cirrhosis group (P = 0.049), and the accompanying mosaic architecture was also more commonly seen in the cirrhosis group (P = 0.048). The ADC values of the lesions were not different among the three groups (P = 0.899). CONCLUSION: MRI may provide valuable information for the diagnosis and differential diagnosis of cHCC-CC in normal, fibrotic, and cirrhotic livers. The nodule size, enhancement pattern, and the presence of mosaic architecture in cHCC-CC differ between different degrees of background liver disease.

Efficacy and Safety of Endoscopic Submucosal Dissection for Colorectal Carcinoids.

BACKGROUND & AIMS: Although endoscopic submucosal dissection (ESD) of colorectal carcinoids is increasing, little is known about long-term outcomes of patients. We investigated the efficacy and safety of ESD of colorectal carcinoids and evaluated long-term outcomes, including local recurrence and metastasis. METHODS: We performed a retrospective analysis of data collected from 239 consecutive patients with colorectal carcinoids <20 mm who underwent endoscopic ultrasonography (to evaluate the size of tumor and the depth of invasion), followed by ESD from January 2007 through October 2012 at the Zhongshan Hospital of Fudan University. Histology and patient data were collected during a median follow-up period of 52 months (range, 25-94 months) to determine tumor stage and type, completeness of resection, complications, tumor recurrence, and distant metastasis. RESULTS: En bloc resection was achieved for all of the 239 treated lesions; tumor tissues were completely resected for 216 of the lesions (90.38%). Eight patients had ESD-related complications (3.35%). As more ESDs were performed by endoscopists, the rate of complete tumor resection increased, and the rate of complications decreased. ESD of carcinoids in colon increased the risk of non-R0 resection and the rate of complications. During the follow-up period, all patients remained free from local recurrence. However, distant metastases were detected in 6 patients (2.51%); lymphovascular invasion was a risk factor for metastasis. CONCLUSIONS: ESD is effective for the resection of rectal carcinoids <20 mm and causes complications in less than 4% of patients. ESD for colonic carcinoids is feasible but associated with a higher non-R0 resection rate and a trend toward higher complications risk. Tumor features and stage determine risk for distant metastasis, so long-term follow-up is essential.

Overexpression of Insig-1 protects ß cell against glucolipotoxicity via SREBP-1c.

BACKGROUND: High glucose induced lipid synthesis leads to ß cell glucolipotoxicity. Sterol regulatory element binding protein-1c (SREBP-1c) is reported to be partially involved in this process. Insulin induced gene-1 (Insig-1) is an important upstream regulator of Insig-1-SREBPs cleavage activating protein (SCAP)-SREBP-1c pathway. Insig-1 effectively blocks the transcription of SREBP-1c, preventing the activation of the genes for lipid biosynthesis. In this study, we aimed to investigate whether Insig-1 protects ß cells against glucolipotoxicity. METHODS: An Insig-1 stable cell line was generated by overexpression of Insig-1 in INS-1 cells. The expression of Insig-1 was evaluated by RT-PCR and Western blotting, then, cells were then treated with standard (11.2 mM) or high (25.0 mM) glucose for 0 h, 24 h and 72 h. Cell viability, apoptosis, glucose stimulated insulin secretion (GSIS), lipid metabolism and mRNA expression of insulin secretion relevant genes such as IRS-2, PDX-1, GLUT-2, Insulin and UCP-2 were evaluated. RESULTS: We found that Insig-1 suppressed the high glucose induced SREBP-1c mRNA and protein expression. Our results also showed that Insig-1 overexpression protected ß cells from ER stress-induced apoptosis by regulating the proteins expressed in the IRE1α pathway, such as p-IRE1α, p-JNK, CHOP and BCL-2. In addition, Insig-1 up-regulated the expression of IRS-2, PDX-1, GLUT-2 and Insulin, down-regulated the expression of UCP-2 and improved glucose stimulated insulin secretion (GSIS). Finally, we found that Insig-1 inhibited the lipid accumulation and free fatty acid (FFA) synthesis in a time-dependent manner. CONCLUSIONS: There results suggest that Insig-1 may play a critical role in protecting ß cells against glucolipotoxicity by regulating the expression of SREBP-1c.

Effect of repaglinide and gliclazide on glycaemic control, early-phase insulin secretion and lipid profiles in.

BACKGROUND: Both repaglinide and gliclazide are insulin secretagogues widely used in the treatment of type 2 diabetes. They stimulate insulin secretion through distinct mechanisms and may benefit patients from different aspects. The present study was to evaluate the effects of repaglinide or gliclazide on glycaemic control, insulin secretion, and lipid profiles in type 2 diabetes patients. METHODS: A total of 47 newly diagnosed type 2 diabetes patients were randomized 1:1 to receive a 4-week treatment with repaglinide or gliclazide. The standard mixed meal tolerance test was performed before and after the treatment. Plasma glucose (PG), insulin concentration, and lipid profiles were measured. The area under insulin concentration curve (AUC(ins)) and the early-phase insulin secretion index (ΔI(30)/ΔG(30)) were calculated. RESULTS: After the trial, fasting and postprandial PG and postprandial insulin improved significantly in both groups (P < 0.05). The maximum insulin concentration occurred earlier in the repaglinide group than that in the gliclazide group. AUC(ins) increased in both groups (P < 0.05), but no significant difference was found between groups. ΔI(30)/ΔG(30) increased in both groups (P < 0.05), especially in the repaglinide group (P < 0.05). Triglyceride and total cholesterol decreased significantly in the repaglinide group in some time points, while no significant change was observed in the gliclazide group. CONCLUSIONS: Repaglinide and gliclazide had similar effects on glycaemic control and total insulin secretion, while repaglinide had more effects on improvements in ß-cell function and lipid metabolism.

[Effect of different glucose concentrations on the expressions of insig-1 and insig-2 mRNA during the differentiation of 3T3-L1 cells].

OBJECTIVE: To determine the effect of different concentrations of glucose on the differentiation of 3T3-L(1) and the expression of insig-1 and insig-2 mRNA, and to explore the effect of insulin-induced gene in the differentiation and formation of adipocytes and lipogenesis. METHODS: The 3T3-L(1) cells were induced to differentiate in high glucose concentration (25 mol/L G.S), low glucose concentration (5.5 mol/L G.S), and mannitol (19.5 mol/L Mannitol +5.5 mol/L G.S), respectively. The differentiation of 3T3-L(1) cells was examined by oil red "O" straining, and the expression of insig-1,insig-2 mRNA and AP2 mRNA was examined by RT-PCR and in situ hybridization. RESULTS: With the differentiation of 3T3-L(1) cells, the expression of insig-1 and insig-2 mRNA was gradually up-regulated. The expression of insig-1 and insig-2 mRNA significantly increased while AP(2) mRNA decreased in the low glucose concentration inducing group and mannitol inducing group. In the high glucose concentration inducing group, the cell differentiation was poor (P<0.05). There was no difference between the low glucose concentration and the mannitol group in the differentiation of 3T3-L(1) cells, and in the expression of insig-1 and insig-2 and AP(2) mRNA. CONCLUSION: Different concentrations of glucose may influence the cell differentiation and the low glucose concentration promotes insig-1 and insig-2 gene expression, which may lead to the inhibition of the differentiation and lipogenesis of preadipocytes.

[Construction and expression of fusion gene eukaryotic expression plasmid of pEGFP-C(3)-insig2 and its influence to downstream genes].

AIM: To construct the eukaryotic expression plasmid of insig2 gene and detect the expression of downstream gene adiponectin and adipocyte fatty acid-binding protein 2 (AP2) after the transfection of 3T3-L1 cells. METHODS: Insig2 gene of the mouse was amplified by RT-PCR and then cloned into the eukaryon expression vector pEGFP-C(3), After confirmed by double restriction enzyme digestion analysis and DNA sequencing, pEGFP-C(3)-insig2 was transfected into 3T3-L1 cells by lipofectamine 2000. The expression of insig2 and downstream gene in the 3T3-L1 cells were detected by RT-PCR and fluorescence microscope. RESULTS: The eukaryotic expression plasmid of pEGFP-C(3)-insig2 was constructed. The expression of fusion protein in the endochylema was confirmed. The transcription of adiponectin mRNA and AP2 mRNA was down-regulated after transfection for 24 h and 72 h. CONCLUSION: The eukaryotic expression plasmid of pEGFP-C(3)-insig2 is successfully constructed. The transfected insig2 may have an effect on fat metabolism of 3T3-L1 cells.

[Expression of hCTLA4-Ig mediated by adeno-associated virus in porcine islets and their biological activity].

OBJECTIVE: To evaluate the expression of hCTLA4-Ig and their biological function in newborn porcine islets (NPIs) transfected with AAV-hCTLA4-Ig. METHODS: Cultured NPIs were transfected with AAV-hCTLA4-Ig. The expression of CTLA4-Ig in these NPIs was assayed by RT-PCR and immunocytochemistry. The levels of IL-2, IFN-gamma, and TNF-alpha in the culture medium were assayed by ELISA after these cells the co-cultured with human. The response of glucose-stimulated insulin secretion was observed in the transgene group and the control group. RESULTS: The expressions of CTLA4-Ig mRNA and protein were detected in the transgene group. The levels of cytokines were obviously lower in the transgene group than those in the control group (P<0.01). There was no significant difference in the response of glucose-stimulated insulin release between the transgene group and the control group (P>0.05). CONCLUSION: AAV mediated hCTLA4-Ig expression in NPIs could inhibit T lymphocyte to produce cytokines, while the endocrine functions of the NPIs were not significantly affected.