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China started the pilot project of subsidy on desertification land protection in 2013. It had been established that 71 national desertification regions were closed and protected, and followed up to monitor for several years in five northwest provinces, Inner Mongolia and Tibet since 2016, while the valuable research conclusion had not been stilly taken. In this paper, the related research and practice at domestic and abroad were reviewed. The four suggestions were put forward for the problem to be solved in time by discussing the closed target and theoretical carrying capacity, based on the key factors on affecting grassland vegetation, the more important issues and the effect of grazing prohibition and monitor as follow. 1) The achievement of investigation and monitor of closed sand land and grazing prohibition during the past years should be concluded in time for providing the basis for government management and improving the closed sand land and grazing prohibition scheme and the next decision-making. 2) The theoretical carrying capacity of desertification region should be determined, such as the actual safe carrying capacity by the basis of the theoretical carrying capacity. 3) In order to improve the practical value of monitoring data, the monitored plot should be compressed, and further revised the monitoring index system. 4) The monitoring research on the benefit of closed sand land and grazing prohibition should be shifted from monitoring the response of vegetation by grazing intensity in the past to monitoring the response of land desertification. [ABSTRACT FROM AUTHOR]

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Objective　To study the protective effect of active peptide GRGDS on rat nerve cells (PC12 cells) in oxygen glucose deprivation (OGD) injury model and explore its mechanism of action. Methods　PC12 cells were divided into control group, ODG group, and active peptide GRGDS treatment group. The injury model was established by simulating in vitro cerebral ischemia by oxygen and sugar deprivation. MTT and flow cytometry were used to detect apoptosis after oxygen-glucose deprivation. ELISA method was used to detect the changes of inflammatory factors TNF-α and IL-1β in PC12 cell supernatant after oxygen-glucose deprivation. Western blot was used to detect the expression of apoptosis pathway-related proteins. Results　The results of MTT and flow cytometry showed that the active peptide GRGDS significantly reduced the apoptosis of PC12 cells after oxygen glucose deprivation (P<0.05). ELISA test results showed that the active peptide GRGDS significantly reduced the content of TNF-α and IL-1β in the supernatant of PC12 cells after oxygen-glucose deprivation. (P<0.05). Western blot results showed that the active peptide GRGDS significantly reduced the expression levels of p-JNK, Bax, and cleaved caspase 3 in PC12 cells mediated by oxygen-glucose deprivation injury (P <0.01). Conclusion　The active peptide GRGDS has protective effect on PC12 cells damaged by oxygen and glucose deprivation. The mechanism may be related to anti-apoptotic and anti-inflammatory effects. [ABSTRACT FROM AUTHOR]