Amniotic Epithelial Cells Accelerate Diabetic Wound Healing by Modulating Inflammation and Promoting Neovascularization.

Human amniotic epithelial cells (hAECs) are nontumorigenic, highly abundant, and low immunogenic and possess multipotent differentiation ability, which make them become ideal alternative stem cell source for regenerative medicine. Previous studies have demonstrated the therapeutic potential of hAECs in many tissue repairs. However, the therapeutic effect of hAECs on diabetic wound healing is still unknown. In this study, we injected hAECs intradermally around the full-thickness excisional skin wounds of db/db mice and found that hAECs significantly accelerated diabetic wound healing and granulation tissue formation. To explore the underlying mechanisms, we measured inflammation and neovascularization in diabetic wounds. hAECs could modulate macrophage phenotype toward M2 macrophage, promote switch from proinflammatory status to prohealing status of wounds, and increase capillary density in diabetic wounds. Furthermore, we found that the hAEC-conditioned medium promoted macrophage polarization toward M2 phenotype and facilitated migration, proliferation, and tube formation of endothelial cells through in vitro experiments. Taken together, we first reported that hAECs could promote diabetic wound healing, at least partially, through paracrine effects to regulate inflammation and promote neovascularization.

Risk factors for hypertrophic burn scar pain, pruritus, and paresthesia development.

Hypertrophic scar pain, pruritus, and paresthesia symptoms are major and particular concerns for burn patients. However, because no effective and satisfactory methods exist for their alleviation, the clinical treatment for these symptoms is generally considered unsatisfactory. Therefore, their risk factors should be identified and prevented during management. We reviewed the medical records of 129 postburn hypertrophy scar patients and divided them into two groups for each of three different symptoms based on the University of North Carolina "4P" Scar Scale: patients with scar pain requiring occasional or continuous pharmacological intervention (HSc pain, n = 75) vs. patients without such scar pain (No HSc pain, n = 54); patients with scar pruritus requiring occasional or continuous pharmacological intervention (HSc pruritus, n = 63) vs. patients without such scar pruritus (No HSc pruritus, n = 66); patients with scar paresthesia that influenced the patients' daily activities (HSc paresthesia, n = 31) vs. patients without such scar paresthesia (No HSc paresthesia, n = 98). Three multivariable logistic regression models were built, respectively, to identify the risk factors for hypertrophic burn scar pain, pruritus, and paresthesia development. Multivariable analysis showed that hypertrophic burn scar pain development requiring pharmacological intervention was associated with old age (odds ratio [OR] = 1.046; 95% confidence interval [CI], 1.011-1.082, p = 0.009), high body mass index (OR = 1.242; 95%CI, 1.068-1.445, p = 0.005), 2-5-mm-thick postburn hypertrophic scars (OR = 3.997; 95%CI, 1.523-10.487, p = 0.005), and 6-12-month postburn hypertrophic scars (OR = 4.686; 95%CI, 1.318-16.653, p = 0.017). Hypertrophic burn scar pruritus development requiring pharmacological intervention was associated with smoking (OR = 3.239; 95%CI, 1.380-7.603; p = 0.007), having undergone surgical operation (OR = 2.236; 95%CI, 1.001-4.998; p = 0.049), and firm scars (OR = 3.317; 95%CI, 1.237-8.894; p = 0.017). Finally, hypertrophic burn scar paresthesia development which affected the patients' daily activities was associated with age (OR = 1.038; 95%CI, 1.002-1.075; p = 0.040), fire burns (OR = 0.041; 95%CI, 0.005-0.366; p = 0.004, other burns vs. flame burns), and banding and contracture scars (OR = 4.705; 95%CI, 1.281-17.288, p = 0.020).

[Impact of wind-water alternate erosion on the characteristics of sediment particles].

Wind and water are the two dominant erosion agents that caused soil and water losses in the wind-water alternate erosion region on the Loess Plateau. It is meaningful to study the impact of wind-water alternate erosion on the characteristics of soil particles for understanding the response of soil quality and environment to erosion. Through wind tunnel combined rainfall simulation, this paper studied the characteristics of the erosive sediment particles under the effect of wind-water alternate erosion. The results showed that the particles of 0-1 cm soil were coarsened by wind erosion at the wind speeds of 11 and 14 m x s(-1) compared with no wind erosion. Soil fine particles (< 0.01 mm) decreased by 9.8%-10.8%, and coarse particles (> 0.05 mm) increased by 16.8%-20.8%. The physical property of surface soil was changed by the wind erosion, which, in turn, caused an increase in finer particles content in the sediment. Compared with no wind erosion, fine particles (< 0.01 mm) in sediment under the water-wind alternate erosion increased by 2.7%-18.9% , and coarse particles (> 0.05 mm) decreased by 3.7%-9.3%. However, the changing trend of erosive sediment particles after the wind erosion at wind speeds of 11 and 14 m x s(-1) was different along with the rainfall intensity and duration. The erosive sediment particles at the rainfall intensities of 60, 80, 100 mm x h(-1) changed to greater extents than at the 150 mm x h(-1) rainfall intensity with longer than 15 min runoff flowing.

Sediment sources of Yan'gou watershed in the Loess Hilly region China under a certain rainstorm event.

At present the large scale vegetation restoration and intensive oil exploiting had brought huge influence on local environment in Yan'an region. the sediment yield data form series experiment plots and hydrological monitoring station in the Yan'an watershed after one rainfall event on July 2, 2005, which included sediment from different land uses (crop-land plot, vegetation plots, hard road surface) and 3 types roads(mountain-road brunches, mountain-road, and mountain-transport way) has been analyzed. Results showed that the erosion intensity of the 3 type roads was respectively 500 t/km(2), 3163 t/km(2), and 13500 t/km(2). The sediment from cropland and grass, shrub land was within 6-184 t/km(2). It stated that sediment from road area which only covered 1% of total area accounted for 42.3% of the total sediment yield, far beyond that from other uses of land. Sediment from grass-land and shrub-land, which covered 70.5% of watershed area, shared 26.7% of the total sediment. The further analysis showed that the 41.2% of total sediment could be detained by re-vegetation. On the contrary, that road constructing brought heavy sediment which offset the benefit of vegetation restore by 58.4%. the suggestion were to adjust our strategy from slope management to the road erosion mitigation Many studies have confirmed it is an important measure to return the steep slope farming land to green, and to restore vegetation in line with local conditions to prevent soil erosion in the Loess Plateau [1, 2]. To implement the measure in western region, the researches on "Grain for Green", returning farmland to forest and grassland, has become popular [3, 4]. Many scholars studied the effects of farming land and trees and grass land on soil water storage [2, 5]. Tang Keli stated that the slope land for farming was the main source of the sediment in Yellow river, and the maximum gradient slope for farming land use was 25° [6]. Many authorities not only pointed out that a far-reaching influence of land-use changes on the distribution of sediment source area but also put forward some new ideas about returning farming to green in Loess Plateau [7, 8]. However, we were still not sure the contribution of returning farmland to forest and grassland on reducing sediment yield of the valley and known it was difficult to identify its contribution to the total sediment yield. Analysis on the contribution of the stream channel and slope sediment yield had some results already [9, 10]. It was still too early to make clear the relationship between the sediment sources changes of the valley and the management. At present, Ecological restoration in the Loess Plateau caused the sediment form the slope land declining [3]. Due to human economic activities, the mountain road developed rapidly, it is inevitable that road erosion has been intensified [11]. A. Rijsdijk and LA Bruijnzeel (1991), [12] based the valley Konto observation, pointed out that although the rural road in the area accounts for only 3% of the area, but the impact on the sediment of this area was tremendous. Nyssen J, Moneryersons J. et al (2002) [13] also think that road without protection is one of the main sources of sediment. Many kinds of protective measures have great importance to the road erosion control. So attentions were paid to the study on the protection all kind of roads. Then what will happen to the soil erosion of the watershed, driven by the vegetation restoration and new road construction? What will happen to the proportion of sediment quality from slope land, road area and gully? A correct understanding of the sediment sources pattern of the typical watershed is of great significance on assessment the roles of vegetation to slope management and the roles of prevention the linear path erosion.

[Sediment-yielding process and its mechanisms of slope erosion in wind-water erosion crisscross region of Loess Plateau, Northwest China].

Due to the coupling effects of wind and water erosions in the wind-water erosion crisscross region of Loess Plateau, the slope erosion in the region was quite serious, and the erosion process was quite complicated. By using wind tunnel combined with simulated rainfall, this paper studied the sediment-yielding process and its mechanisms of slope erosion under the effects of wind-water alternate erosion, and quantitatively analyzed the efffects of wind erosion on water erosion and the relationships between wind and water erosions. There was an obvious positive interaction between wind and water erosions. Wind erosion promoted the development of microtopography, and altered the quantitative relationship between the sediment-yielding under water erosion and the variation of rainfall intensity. At the rainfall intensity of 60 and 80 mm x h(-1), the sediment-yielding without wind erosion decreased with the duration of rainfall and tended to be stable, but the sediment-yielding with wind erosion decreased to a certain valley value first, and then showed an increasing trend. At the rainfall intensity of 60, 80, and 100 mm x h(-1), the sediment-yielding with the wind erosion at speeds of 11 and 14 m x s(-1) increased by 7.3%-27.9% and 23.2%-39.0%, respectively, as compared with the sediment-yielding without wind erosion. At the rainfall intensity of 120 and 150 mm x h(-1) and in the rainfall duration of 15 minutes, the sediment-yielding with and without wind erosion presented a decreasing trend, but, with the increase of rainfall duration, the sediment-yielding with wind erosion showed a trend of decreasing first and increasing then, as compared with the sediment-yielding without wind erosion. The mechanisms of wind-water alternate erosion were complicated, reflecting in the mutual relation and mutual promotion of wind erosion and water erosion in the aspects of temporal-spatial distribution, energy supply, and action mode of erosion forces.

[Runoff and sediment processes and anti-erosion effects of grass-covered earth road in loess hilly region].

A laboratory simulation test with slope-adjustable steel tank and artificial rainfall was conducted to study the runoff and sediment processes of uncovered and Poa pratensis L.-planted earth roads, and the anti-erosion effects of P. pratensis-planted earth road. At the same rainfall intensity and slope, the runoff coefficient of P. pratensis-planted earth road was larger than that of uncovered earth road. For the two kinds of earth roads, their runoff coefficients all increased with increasing rainfall intensity and slope. At the same slope but different rainfall intensity, the runoff coefficient had a logarithmic relationship with rainfall duration, and a quadratic relationship with slope or rainfall intensity. Soil erosion rate increased with increasing rainfall intensity or slope, and was smaller on the P. pratensis-planted earth road at the same rainfall intensity. The average antierosion efficacy of P. pratensis-planted earth road was 47.22% at different rainfall intensity, and was 26.24% at different slope. Because of its higher roughness and higher road surface resistance coefficient, P. pratensis-planted earth road had a lower sediment yield and a decreased sediment transport.

[Benefit of sediment reduction by biological measures in the watershed scale].

Based on the measured data and the model of plotted watershed hydrology, the benefit of sediment reduction by biological harnesses of soil and water conservation was studied in the watershed scale. The result indicated that the erosion modulus in Wangdonggou watershed, which were 1869 t.km-2, 1050 t.km-2, 383 t.km-2, and 504 t.km-2 in the periods of the sixth, seventh, eighth, and ninth five-year plans, respectively, were gradually reduced by comprehensive measures. Taken out the effect of rainfall, the sediment reduction by biological measures of soil and water conservation was increased by 24.1% and 22.4% in the periods of eighth and ninth five-year plans compared to that in the seventh five-year plan.