[Physiological response of corn seedlings to changes of wind-sand flow strength].

Corn seedlings are often harmed by strong wind-sand in the spring in semi-arid wind-sand area of west of Northeast China. In order to understand physiological response mechanisms of the corn seedlings to wind-sand damage, the changes in MDA content, membrane permeability, protective enzymes activities and osmotic regulation substances at 0 (CK) , 6, 9, 12, 15 and 18 m . s-1 wind speed (wind-sand flow strength: 0, 1.00, 28.30, 63.28, 111.82 and 172.93 g . cm-1 . min-1, respectively) for 10 min duration were studied during the spring, 2013 in the Horqin Sand Land of Inner Mongolia. The results showed that effects of wind-sand flow blowing on the RWC of the corn seedling were lighter in the 6-12 m . s-1 treatments, but the RWC decreased by 19.0% and 18.7% in the 15 m . s-1 and 18 m . s-1 treatments compared to the CK, respectively. The MDA content tended to decline with increasing the wind-sand flow strength, and decreased by 35.0% and 39.0% in the 15 m . s-1 and 18 m . s-1 treatments compared to the CK, respectively. The membrane permeability increased significantly with increasing the wind-sand flow strength, and increased by 191.3% and 187.8% in the 15 m . s-1 and 18 m . s-1 treatments compared to the CK, respectively. With the increase of wind-sand flow strength, SOD activities decreased and changes of CAT activities were not significant, only POD activities increased significantly, which played an important role in the process of scavenging reactive oxygen species and protecting cell membrane against damage. For lighter water stress caused, by wind-sand flow blowing, proline and soluble sugar did not play any role in osmotic adjustment, but the proline content increased by 11.4% and 24.5% in the 15 m . s-1 and 18 m . s-1 treatments compared to the CK, respectively, which played an important role in osmotic adjustment.

[Effects of sand burial on growth and physiological process of Agriophyllum squarrosum seedlings in Horqin Sand Land of Inner Mongolia, North China].

In 2010-2011, a sand burial experiment was conducted on the Horqin Sand Land of Inner Mongolia to study the growth characteristics and physiological properties of Agriophyllum squarrosum seedlings under different depths of sand burial. The A. squarrosum seedlings had stronger tolerance against sand burial. The seedling growth could be severely inhibited when the burial depth exceeded seedling height, but some seedlings could still be survived when the burial depth exceeded 1.66 times of seedling height. When the burial depth did not exceed the seedling height, the seedling MDA content and membrane permeability had no significant change, but the lipid peroxidation was aggravated and the cell membrane was damaged with increasing burial depth. Under sand burial stress, the seedling SOD and POD activities and proline content increased significantly, while the seedling CAT activity and soluble sugar content deceased. Sand burial decreased the leaf photosynthetic area and damaged cell membrane, inducing the increase of seedling mortality and the inhibition of seedling growth. The increase of SOD and POD activities and proline content played a definite role in reducing the sand burial damage to A. squarrosum seedlings.

[Detection of BCR/ABL fusion gene by fluorescence in situ hybridization and its clinical application].

This study was aimed to investigate the clinical value of detecting BCR/ABL fusion gene by fluorescence in situ hybridization (FISH). The conventional cytogenetic test and detection of BCR/ABL fusion gene by FISH for bone marrow of patients with newly diagnosed chronic myeloproliferative disease or myelodysplastic and myeloproliferative disorders, acute lymphocytic leukemia and chronic myelogenous leukemia (CML) after allogeneic hematopoietic stem cell transplantation were carried out. The results showed that (1) out of 46 newly diagnosed as chronic myeloproliferative disease or myelodysplastic and myeloproliferative disorders, 22 cases were diagnosed as CML, the FISH detection showed all positive (100%), while cytogenetic test showed 86.4% (19/22) positive, in the other 24 patients who were diagnosed as other chronic myeloproliferative disease or myelodysplastic and myeloproliferative disorders, BCR/ABL fusion gene all were be detected as negative 100% by FISH, while the cytogenetic test of bone marrow in 3 cases supported the diagnosis of CML, and the diagnosis of myelodysplastic disorder in 1 case; (2) in 3 out of 7 acute lymphocytic leukemia cases the BCR/ABL fusion gene could not be detected by FISH; (3) the BCR/ABL fusion gene could be detected by FISH in 2 cases of CML received allogeneic hematopoietic stem cell transplantation, with abnormal threshold 6.5% and 1.2% respectively. It is concluded that the detection of BCR/ABL fusion gene by FISH is sensitive and reliable, which is very important for the diagnosis and differential diagnosis of chronic myeloproliferative disorders, myelodysplastic and myeloproliferative disease, as well as definite diagnosis of Ph(+) acute lymphoblastic leukemia. This method also has an important significance for monitor of minimal residual disease in CML patients received allogeneic hematopoietic stem cell transplantation.

[Anti GVHD effect of the induction of immune tolerance in rats embryo].

OBJECTIVE: To investigate whether the fetal immune tolerance induction could replace the HLA typing for hematopoietic stem cell transplantation. METHODS: Immune tolerance of SD rats was induced by injecting host Wistar rats peripheral blood mononuclear cells into yolk sac of the embryo, afterward the mature male offsprings were used as donor. The host female recipients received lethal dose irradiation and bone marrow transplantation(BMT). The Wistar rats transplanted with bone marrow from donor and unrelated SD rats as well as the rats which received radiation alone were used as control. The survival, histopathologically GVHD, the mental status, food and water intake, coat characteristics, activities were observed. Forty days after BMT, autologous and allogenous skin transplantation between donor and recipient rats was performed to observe the engraftment of solid organ. RESULTS: The survival of the rats received bone marrow grafts from the immune tolerant donor was significantly longer than that of control groups (30 day survival rates were 86.7%, 6.7%, 0%, and 0% respectively), and there was no histopathologically GVHD observed, while in the sham group, the manifestations of GVHD was clearly visible. The skin engraftment rate between the host and the immune tolerant donor was significantly higher than that among non-related rats (84.6% and 0% respectively). CONCLUSION: The induction of immune tolerance in embryo can overcome the HLA barrier and provide a good donor for hematopoietic stem cell and solid organ transplantation.

[Effects of vegetation cover on physical and chemical properties of bio-crust and under-layer soil in Horqin Sand Land].

To understand the effects of different vegetation cover on the bio-crust and its under-layer soil in Horqin Sand Land, the bio-crust and 0-5 cm soil samples in Artemisia frigida, Salix microstachya, Populus simonii, and Pinus sylvestris var. mongolica stands were collected, and their physical and chemical properties were studied. After fifteen years enclosure protection and vegetation establishment, the flowing sand dune in most natural and artificial vegetation sites was covered with bio-crusts. The coverage degree of the crust was 50%-80%, with a thickness of 1-2 cm. In S. microstachya stand, the crust thickness, hardness, and organic matter and nutrient contents were the highest, followed by in P. sylvestris var. mongolica stand, and in A. frigida and A. frigida stands. Moss crust had higher thickness, hardness, and organic matter and nutrient contents than lichen crust. Comparing with those in flowing sand land, the physical and chemical properties of under-layer soil in test stands were improved obviously, the improvement degree being higher under moss crust than under lichen crust, and higher in S. microstachya and P. sylvestris var. mongolica stands than in A. frigida and P. simonii stands. Vegetations with moderate height and rich branches and leaves were more helpful to the development of bio-crust and the improvement of under-layer soil, because they could reduce wind velocity and accumulate more dust and litters, and the development of moss crust was more favorable than lichen crust to the improvement of its under-layer soil.

[Effects of desertification on C and N storages in grassland ecosystem on Horqin sandy land].

Sandy grassland is widespread in northern China, where desertification is very common because of overgrazing and estrepement. However, little is known about the effects of desertification on grassland C and N storages in this region. A field survey was conducted on Horqin sandy grassland, and desertification gradients were established to evaluate the effects of desertification on C and N storages in soil, plant, and litter. The results showed that desertification had deep effects on the contents and storages of grassland C and N. The C and N contents and storages in the grassland decreased significantly with increasing desertification degree. Comparing with those in un-desertified grassland, the C and N contents in lightly, moderately, heavily, and severely desertified grasslands decreased by 56.06% and 48.72%, 78.43% and 74.36%, 88.95% and 84.62%, and 91.64% and 84.62% in 0-100 cm soil layer, and by 8.61% and 6.43%, 0.05% and 25.71%, 2.58% and 27.14%, and 8. 61% and 27. 86% in plant components, respectively. Relevantly, the C and N storages decreased by 50.95% and 43.38%, 75.19% and 71.04%, 86.76% and 81.48%, and 91.17% and 83.17% in plant underground components in 0-100 cm soil layer, and by 25.08% and 27.62%, 30.90% and 46.55%, 73.84% and 80.62%, and 90.89% and 87.31% in plant aboveground components, respectively. In 2000, the total area of desertified grassland in Horqin sandy land was 30152. 7 km2, and the C and N loss via desertification reached up to 107.53 and 9.97 Mt, respectively. Correlation analysis indicated that the decrease of soil C and N contents was mainly come from the decreased soil fine particles caused by wind erosion in the process of desertification, and the degradation of soil texture- and nutrient status led finally to the rapid decrease of C and N storages in plant biomass and litter.