[Temporal and Spatial Variation Characteristics and Source Analysis of Agricultural Non-point Source Pollution Load in Guangdong During the Past 20 Years].

The agricultural non-point source pollution (ANPSP) load in Guangdong province is very large and has a serious impact on the regional ecological environment. Inventory analysis was used to assess and analyze the temporal and spatial variation characteristics of the ANPSP load of Guangdong province during 1999-2019, and the sources of ANPSP were discussed, as well as the relationship between them. The results showed that, during the past 20 years, the total ANPSP pollution loads of Guangdong province decreased by 6.08%, and the pollution loads of chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) increased by -11.88%, 4.99%, and 26.17%, respectively. The input intensity of chemical fertilizers and pesticides increased by 112.19% and 60.38%, respectively. The Pearl River Delta had the highest ANPSP loads in Guangdong province, followed by those in northern, western, and eastern Guangdong. Livestock and poultry breeding were the main sources of COD, the total percent fertilizers and livestock and poultry breeding were the main sources of TN, and livestock and poultry breeding and aquaculture were the main sources of TP. In addition, the contribution of pollutants discharged from aquaculture showed an obvious increasing trend. There were certain differences in the pollution sources in different regions. In western Guangdong, northern Guangdong, and eastern Guangdong, livestock and poultry breeding were the main sources of COD and TP, and fertilizer was the main source of TN; by contrast in the Pearl River Delta, aquaculture had become the main source of TN and TP pollution loads. The correlation results showed that the decline in the total ANPSP in Guangdong province was mainly due to the increase in high urbanization rate and the decrease in the proportion of rural population. In general, there were stage changes in the time and differences in spatial characteristics and sources of ANPSP in Guangdong province. A combination of comprehensive treatment and targeted pollution treatment should be adopted, and fertilizer reduction measures and pollution treatment in the aquaculture should be strengthened in an all-around way, focusing on strengthening the treatment of pollution from aquaculture in the Pearl River Delta region and the treatment of rural life pollution in northern Guangdong.

Alginate/gelatin blended hydrogel fibers cross-linked by Ca2+ and oxidized starch: Preparation and properties.

Alginate/gelatin blended hydrogel fibers were successfully prepared based on sodium alginate cross-linked by Ca2+ and gelatin cross-linked by oxidized starch through the wet spinning process. The structure, surface morphologies, swelling properties of alginate hydrogel fibers and alginate/gelatin blended hydrogel fibers were examined by Fourier transform infrared analysis (FTIR), cross-linking degree test, element analysis test and scanning electron microscopy (SEM). While mechanical properties test, water absorption and retention properties test provide the mechanical, water absorption and retention properties. FTIR, cross-linking degree and element analysis results indicate that there is gelatin remaining in alginate/gelatin blended hydrogel fibers. However, the cross-linking of gelatin by oxidized starch is not completed with some dissociative gelatin solvated in the coagulation bath. Among the mentioned fibers, FS10G2 is the best to improve the properties of alginate/gelatin blended hydrogel fibers with an optimal mass ratio of sodium and gelatin. The excessive additive amount of gelatin leads to the aggregation of gelatin in alginate/gelatin blended hydrogel fibers, making the worse compatibility between alginate and gelatin. It also destroys the mechanical properties of alginate/gelatin blended hydrogel fibers. These alginate/gelatin blended hydrogel fibers might have a potential application in the biomedical fields.

Human Umbilical Cord Wharton's Jelly Derived Mesenchymal Stromal Cells May Attenuate Sarcopenia in Aged Mice Induced by Hindlimb Suspension.

BACKGROUND Since the use of human umbilical cord Wharton's Jelly derived mesenchymal stromal cells (hWJ-MSCs) to treat sarcopenia has not been explored, we studied the effects of hWJ-MSCs in aged male C57BL/6J mice with sarcopenia induced by hindlimb suspension, and explored the potential mechanism. MATERIAL AND METHODS Hindlimb suspension was used to induce sarcopenia in 24-month-old C57BL/6J mice and green fluorescent protein-tagged hWJ-MSCs and controls were transplanted into mice via tail vein or local intramuscular injection. After hWJ-MSC transplantation, changes in whole body muscle strength and endurance, gastrocnemius muscle weight and myofiber cross-sectional area (CSA) were studied. Proliferation of skeletal muscle stem cell, apoptosis, and chronic inflammation were also investigated. RESULTS We demonstrated that whole body muscle strength and endurance, gastrocnemius muscle mass, and CSA were significantly increased in hWJ-MSC-transplanted mice than in controls (P<0.05). In hWJ-MSC-transplanted mice, apoptotic myonuclei was reduced, and BrdU and Pax-7 expression indices of gastrocnemius muscles were increased (P<0.05). Tumor necrosis factor (TNF)-α and interleukin (IL)-6 were downregulated, and IL-4 and IL-10 were upregulated (P<0.05). CONCLUSIONS hWJ-MSCs may ameliorate sarcopenia in aged male C57BL/6J mice induced by hindlimb suspension, and this may be via activation of resident skeletal muscle satellite cells, reduction of apoptosis, and less chronic inflammation.

[Therapeutic effect of acupoint-injection combined with electroacupuncture on chronic pharyngitis].

OBJECTIVE: To compare therapeutic effects of acupoint-injection combined with electroacupuncture and oral administration of medicine on chronic pharyngitis. METHODS: The treatment group of 71 cases were treated by injection of fufangdanshen injectio into Tiantu (CV 22) combined with electroacupuncture at Renying (ST 9), and the control group of 51 cases were treated by oral administration of acetylspiramycin and qingyan tablet. RESULTS: The cured rate and the total effective rate were 60.5% and 90.1% in the treatment group, and 21.6% and 68.6% in the control group, with significantly differences between the two groups (P < 0.01). CONCLUSION: Therapeutic effect of acupoint-injection combined with electroacupuncture on chronic pharyngitis is superior to that of oral administration of medicine.