Integrating fractional amplitude of low-frequency fluctuation and functional connectivity to investigate the mechanism and prognosis of severe traumatic brain injury.

Objective: Functional magnetic resonance imaging (fMRI) has been used for evaluating residual brain function and predicting the prognosis of patients with severe traumatic brain injury (sTBI). This study aimed to integrate the fractional amplitude of low-frequency fluctuation (fALFF) and functional connectivity (FC) to investigate the mechanism and prognosis of patients with sTBI. Methods: Sixty-five patients with sTBI were included and underwent fMRI scanning within 14 days after brain injury. The patient's outcome was assessed using the Glasgow Outcome Scale-Extended (GOSE) at 6 months post-injury. Of the 63 patients who met fMRI data analysis standards, the prognosis of 18 patients was good (GOSE scores ≥ 5), and the prognosis of 45 patients was poor (GOSE scores ≤ 4). First, we apply fALFF to identify residual brain functional differences in patients who present different prognoses and conjoined it in regions of interest (ROI)-based FC analysis to investigate the residual brain function of sTBI at the acute phase of sTBI. Then, the area under the curve (AUC) was used to evaluate the predictive ability of the brain regions with the difference of fALFF and FC values. Results: Patients who present good outcomes at 6 months post-injury have increased fALFF values in the Brodmann area (7, 18, 31, 13, 39 40, 42, 19, 23) and decreased FC values in the Brodmann area (28, 34, 35, 36, 20, 28, 34, 35, 36, 38, 1, 2, 3, 4, 6, 13, 40, 41, 43, 44, 20, 28 35, 36, 38) at the acute phase of sTBI. The parameters of these alterations can be used for predicting the long-term outcomes of patients with sTBI, of which the fALFF increase in the temporal lobe, occipital lobe, precuneus, and middle temporal gyrus showed the highest predictive ability (AUC = 0.883). Conclusion: We provide a compensatory mechanism that several regions of the brain can be spontaneously activated at the acute phase of sTBI in those who present with a good prognosis in the 6-month follow-up, that is, a destructive mode that increases its fALFF in the local regions and weakens its FC to the whole brain. These findings provide a theoretical basis for developing early intervention targets for sTBI patients.

Impacts of Artificial Underground Reservoir on Groundwater Environment in the Reservoir and Downstream Area.

Artificial underground reservoirs have changed the hydrological cycle from its natural condition. This modification may trigger a series of negative environmental effects both at the local and regional levels. This study investigated the impact of the Wanghe artificial underground reservoir on groundwater flow and quality in the reservoir and its downstream area. Wanghe is a typical artificial underground reservoir scheme in China, which assumes the dual function of fresh-water preservation and control of seawater intrusion. The groundwater flow pattern has changed after the reservoir construction, and the water level in the reservoir rose rapidly. Evaluation of long-term groundwater level fluctuation suggested that the reservoir deprived the downstream aquifer of the runoff, which it received under the natural flow regime. A preliminary isotopic evaluation using 3H was developed to understand the groundwater flow and renewal rates in the study area. The uniform distribution of tritium levels in the reservoir indicated that the stored water was well-mixed in both horizontal and vertical directions. The intervention on groundwater circulation also made differences in groundwater renewal rates between stored and downstream water. Field investigations on groundwater nitrogen pollution showed that the construction of the artificial underground reservoir resulted in nitrate accumulation in the stored water. Agriculturally derived nitrate was the largest contributor, and NO 3 - concentration varied considerably over time due to fertilization and irrigation activities, rainfall, and denitrification. NO 3 - -N distributed homogeneously in the reservoir, which was attributed to the construction of the subsurface dam, land use pattern and artificial groundwater flow.

Quantifying the effects of conservation practices on soil, water, and nutrients in the Loess Mesa Ravine Region of the Loess Plateau, China.

A large number of soil and water conservation programs have been implemented on the Loess Plateau of China since the 1950s. To comprehensively assess the merits and demerits of the conservation practices is of great importance in further supervising the conservation strategy for the Loess Plateau. This study calculates the impact factors of conservation practices on soil, water, and nutrients during the period 1954-2004 in the Nanxiaohegou Catchment, a representative catchment in the Loess Mesa Ravine Region of the Loess Plateau, China. Brief conclusions could be drawn as follows: (1) Soil erosion and nutrient loss had been greatly mitigated through various conservation practices. About half of the total transported water and 94.8 % of the total transported soil and nutrients, had been locally retained in the selected catchment. The soil retained from small watersheds do not only form large-scale fertile farmland but also safeguard the Yellow River against overflow. (2) Check dam was the most appropriate conservation practice on the Loess Plateau. In the selected catchment, more than 90 % of the retained soil and water were accomplished by the dam farmland, although the dam farmland occupied only 2.3 % of the total area of all conservation measures. Retention abilities of the characteristic conservation practices were in the following order: dam farmland > terrace farmland > forest land and grassland. (3) The conservation practices were more powerful in retaining sediment than in reducing runoff from the Loess Plateau, and the negative effects of the conservation practices on reducing water to the Yellow River were relatively slight.

[Absorption characteristics of molybdenum by reed and cattail].

The adsorption characteristics of reed and cattail to molybdenum were studied. The toxicity, removal rate, adsorption process and accumulation of Mo were investigated in the short-term indoor-culture experiment. The effects of Mo adsorbed by two plants in nutrition solution with different concentrations were also studied. Due to the Mo toxicity, the color of stems and leaves of two plants had become scorch and the transpiration was declined. The cattail illustrated higher tolerance to Mo than reed when Mo concentration was in the range of 2-20 mg x L(-1). The removal rate of Mo by cattail was 87%, which was higher than reed (62%) with Mo concentration of 2 mg x L(-1). The absorption process of Mo by two plants was homeostasis, and the passivity absorption was the main absorption mechanism. Mo enrichment amount in cattail was higher than that in reed, and Mo concentration in shoot were higher than that in roots. The results displayed that cattail was Mo hyper accumulator. The absorption of Mo was not enhanced with the increase of nutrition solution concentration, due to the competition of other ions. The study suggested that the absorption capacity of Mo was significant by the two plants, and cattail was better for Mo removal than reed.

Nonpoint-source nitrogen and phosphorus behavior and modeling in cold climate: a review.

Pollution from nonpoint-source (NPS) nitrogen (N) and phosphorus (P) are the main causes of eutrophication in lotic, lentic and coastal systems. The climate of cold regions might play an important role in disturbing environmental behavior of NPS N and P, influencing simulation of watershed scale hydrologic and nonpoint-source pollution models. The losses of NPS N and P increase in regions of cold climate. In cold seasons, accumulations of N and P are accelerated in soil with increasing fine root and aboveground biomass mortality, decreasing plant nutrient uptake, as well as freezing soil. N and P transformation is disturbed by soil frost and snow. Moreover, factors such as physical disruption of soil aggregates, pollutant accumulation in snowpack, and snow melting can all increase the NPS N and P losses to the waterbody. Therefore, NPS N and P in first flush are more serious in cold climate. All these effects, especially frozen soil and snowpack, make great challenges to watershed scale hydrologic and nonpoint-source pollution models simulation in cold climate. Model improvements of snowmelt runoff, nutrient losses in frozen soil, as well as N and P behavior have been initiated and will be continued to evaluate in terms of their performances and suitability with different scale, hydrologic and geologic conditions in the future.

[Methods for river habitat survey and evaluation].

The study of river habitat is the basis for river ecological restoration and basin environmental management. In this paper, the classification, survey methods (including survey scale, sampling density, sampling season, and data recording), and data processing of river habitat were introduced, and the characteristics and application scope of the main methods (or models) widely applied in the world for river habitat evaluation were reviewed from the aspect of the relationships between living species and habitat suitability. Based on the approach of the experiences and methods of habitat research in developed countries, it was suggested that the river regulation in China should be carried out from the viewpoint of river ecosystem restoration.

Pure red cell aplasia due to parvovirus B19 infection after liver transplantation: a case report and review of the literature.

Pure red cell aplasia (PRCA) due to parvovirus B19 (PVB19) infection after solid organ transplantation has been rarely reported and most of the cases were renal transplant recipients. Few have been described after liver transplantation. Moreover, little information on the management of this easily recurring disease is available at present. We describe the first case of a Chinese liver transplant recipient with PVB19-induced PRCA during immunosuppressive therapy. The patient suffered from progressive anemia with the lowest hemoglobin level of 21 g/L. Bone marrow biopsy showed selectively inhibited erythropoiesis with giant pronormoblasts. Detection of PVB19-DNA in serum with quantitative polymerase chain reaction (PCR) revealed a high level of viral load. After 2 courses of intravenous immunoglobulin (IVIG) therapy, bone marrow erythropoiesis recovered with his hemoglobin level increased to 123 g/L. He had a low-level PVB19 load for a 5-mo follow-up period without recurrence of PRCA, and finally the virus was cleared. Our case indicates that clearance of PVB19 by IVIG in transplant recipients might be delayed after recovery of anemia.

Inhibition of PMA-induced endothelial cell activation and adhesion by over-expression of domain negative IkappaBalpha protein.

AIM: NF-kappaB, regulate the expression of cytokine-inducible genes involving immune and inflammatory responses, will be potential therapy approach for allograft from rejection. In this study, we use pCMV- IkappaBalphaM vector to inhibit NF-kappaB activation and investigate the effect of pCMV- IkappaBalphaM in inhibition of T cells adhesion to endothelial cells. METHODS: The NF-kappaB activity was detected with pNF-kappaB reporter gene and electrophoretic mobility shift assay. Expression of cell surface molecules was detected by RT-PCR and flow cytometer. The cell-cell adhesion assay was performed to determine the effect of pCMV-IkappaBalphaM in inhibition of T cells adhesion to endothelial cells. RESULTS: We could find that NF-kappaB activity is inhibited by over-expression of non-degraded IkappaBalpha protein. Expression of adhesion molecules like ICAM-1, VCAM-1, and P-selectin as well as cell-cell adhesion were inhibited significantly by transfection of the pCMV- IkappaBalphaM vector. CONCLUSION: Our results indicate that the pCMV- IkappaBalphaM, which inhibit the activity of NF-kappaB through over-expression of non-degraded IkappaBalpha protein, can be used for gene therapy in diseases involving NF-kappaB activation abnormally like organ transplantation via inhibiting cell adhesion.

[Early expression of pro-inflammatory cytokines in the lung of rat with small-for-size liver transplantation and the significance].

OBJECTIVE: To investigate the expression of tumor necrosis factor-alpha(TNF-alpha), interleukin-1 beta (IL-1beta), and intercellular adhesion molecule-1 (ICAM-1) in the lung of rat with small-for-size liver transplantation and the significance of the expression of these cytokine in lung injury after liver transplantation. METHODS: 150 SD rats were randomly divided into 4 groups: sham operation group (n = 6), whole graft liver transplantation group (n = 48), 50% size graft liver transplantation group (n = 48), and 30% size liver transplantation group (n = 48). Six rats from each group were killed 0.5, 2, 6, and 24 hours after operation. Blood samples from subhepatic inferior vena cava were obtained to examine the plasma TNF-alpha by ELISA. Specimens of lung were obtained to be examined pathologically. RT-PCR was used to examine the expression of TNF-alpha mRNA, IL-1beta mRNA, and ICAM-1 mRNA in lung, and chromatometry was performed to detect the activity of myeloperoxidase (MPO). RESULTS: (1) The plasma TNF-alpha at any time point was higher in the 3 transplantation groups than in the sham operation group. The plasma TNF-alpha 2 hours after operation in the whole graft group was significantly higher than that in the 30% size group (P < 0.05). (2) The expression levels of TNF-alpha mRNA 2 and 6 hours after operation in the whole graft group and in the 50% graft group were significantly higher than those in the 30% graft group (all P < 0.01). The expression levels of TNF-alpha mRNA remained significantly higher than those in the sham operation group since the second hour after operation (all P < 0.01). (3) IL-1beta mRNA was expressed in the 3 liver transplantation groups without significant differences between any levels at all the time points and was not expressed in the sham operation group. The expression of ICAM-1 mRNA was higher at all the time points in the liver transplantation groups than in the sham operation group (P < 0.01 or P < 0.05) without significant difference between the values of any transplantation group at any time point (all P > 0.05). The MPO activity was stronger in the 3 liver transplantation groups at any time point than in the sham operation group (all P < 0.01). The peak occurred 2 hours after operation in the whole graft group and 50% size group and occurred 6 hours after operation in the 30% graft group. The plasma TNF-alpha level was positively correlated to the MPO activity in lung tissue with a correlation coefficient of 0.422 (P < 0.05). (4) The morphology of lung was normal in the sham operation group. Obvious interstitial hyperemia and hemorrhage, neutrophil infiltration, and pulmonary septal thickening were found in the 3 transplantation groups, in particular being severe at the 2-hour time point. CONCLUSION: Increase of plasma TNF-alpha is one of the causes of lung injury after small-for-size liver transplantation. Upregulation of TNF-alpha mRNA, IL-1beta mRNA, and ICAM-1 mRNA expression may be also responsible for the lung injury and their expression may be correlated to the size of graft.