Fabrication and photocatalytic properties of Cu_2S/T-ZnO_w heterostructures via simple polyol process

The Cu2S/tetrapod-like ZnO whisker（T-ZnOw） heterostructures were successfully synthesized via a simple polyol process employing the poly（vinyl pyrrolidone）（PVP） as a surfactant.The as-prepared heterostructures were characterized by X-ray diffraction（XRD）,field emission scanning electron microscopy（FESEM）,X-ray photoelectron spectroscopy（XPS） and Fourier transform infrared（FTIR）.The photocatalytic properties of Cu2S/T-ZnOw nanocomposites synthesized with different PVP concentrations were evaluated by photodegradation of methyl orange（MO） under UV irradiation.The results show that the Cu2S/T-ZnOw nanocomposites exhibit remarkable improved photocatalytic property compared with the pure T-ZnOw.The sample prepared with 3.0 g/L PVP shows an excellent photocatalytic property and the highest photodegradation rate of MO is 97% after UV irradiation for 120 min.Besides,the photocatalytic activity of the photocatalyst has no evident decrease even after four cycles,which demonstrates that the Cu2S/T-ZnOw photocatalyst exhibits an excellent photostability.Moreover,the photocatalytic mechanism of the Cu2S/T-ZnOw nanocomposites was also discussed.

Heterogeneity and plasticity of T helper cells

CD4 T helper （Th） cells play critical roles in adaptive immune responses. They recruit and activate other immune cells including B cells, CD8 T cells, macrophages, mast cells, neutrophils, eosinophils and basophils. Based on their functions, their pattern of cytokine secretion and their expression of specific transcription factors, Th cells, differentiated from naive CD4 T cells, are classified into four major lineages, Thl, Th2, Th17 and T regulatory （Treg） cells, although other Th lineages may exist. Subsets of the same lineage may express different effector cytokines, reside at different locations or give rise to cells with different fates, whereas cells from different lineages may secrete common cytokines, such as IL-2, IL-9 and IL-10, resulting in massive heterogeneity of the Th cell population. In addition, the pattern of cytokine secretion may switch from that of one lineage toward another under certain circumstances, suggesting that Th cells are plastic. Tregs are also more heterogeneous and plastic than were originally thought. In this review, we summarize recent reports on heterogeneity and plasticity of Th cells, and discuss potential mechanisms and implications of such features that Th cells display.

Changes of inducible protein-10 and regulated upon activation, normal T cell expressed and secreted protein in acute rejection of pancreas transplantation in rats

AIM： To investigate the role of IFN-T inducible protein -10 （IP-10） and regulated upon activation, normal T cell expressed and secreted （RANTES） protein in acute pancreatic allograft rejection in rats. METHODS： An experimental model was established using pancreas transplantation diabetic SD rats as the recipient, induced by applying streptozocin （STZ）. Pancreas transplantation was performed with a physiologic method of portal venous and enteric drainage. Rats were divided into two groups, isograft group （group A, n = 24） and allograft group （group B, n = 24） in which either healthy SD rats or Wistar rats served as donors, respectively. Twelve diabetic or healthy SD rats were used as controls. At d 1, 4, 7, and 10 post transplantation, serum IP-10 and RANTES were assessed by ELISA and their expression in the allografts was determined by immunohistochemistry. RESULTS： In group B （allograft group）, the development of acute rejection was significantly correlated with increased serum concentration and tissue expression of IP-10 and RANTES, with a peak level at d 7 post transplantation. In contrast, there was no obvious change before and after transplantation in group A （isograft group）. CONCLUSION： Our study suggests a possible role of IP-10 and RANTES in acute rejection and early monitoring of chemokines may be helpful in predicting the outcome of pancreas transplantation.

Reduction of natural regulatory T cells in thymomas accompanying myasthenia gravis and its possible association with Foxp3 and thymic stromal lymphopoietin

Objective: To investigate the expression of both thymic regulatory T cells (CD4+CD25+Foxp3+cells, Treg) and thymic stromal lymphopoietin (TSLP) in thymomas accompanying myasthenia gravis. Methods: We used immunohistochemistry and real-time reverse trancription polymerase chain reaction (real-time RT-PCR) techniques to determine Foxp3+ Treg counts and the expression levels of Foxp3 mRNA and TSLP mRNA in thymomas of 23 MG patients and thymuses of 4 healthy controls. Results: The CD4+ Foxp3+ nTreg (natural regulatory T cells) counts in thymomas were significantly lower than those in normal thymuses (P<0.01), and the expression levels of Foxp3 mRNA and TSLP mRNA were also lower in thymomas(P<0.01). Among the thymoma types, type B1 thymoma had the highest Foxp3+ nTreg count and standard values of Foxp3 mRNA and TSLP mRNA. There was a strong positive correlation between the mRNA transcriptional levels of Foxp3 and TSLP. Conclusion: The insufficient expression of Foxp3 in thymoma, which may be caused by decreased transcription of TSLP, may result in the reduction of Tregs and cause autoimmune disorders.

Spectrophotometric determination of heparin with safranine T and their interaction mechanism

In weak acidic medium the alkaline cationic Safranine T interacts with acidic biological rnacromolecule heparin intensively causing the change of the molecular conformation, the maximum absorption wavelength and the absorption value. The optimum experimental condition was given and a new method to determine the heparin was established. The linear range was 0.05-2.0 mg/L and the correlation coefficient was 0.9974. The method has been applied to analyze the samples and the results are satisfactory. Furthermore, the interaction mechanism was indicated.

乘积度量空间中扩张型映像的公共不动点定理

在乘积度量空间中,利用自映像对的弱交换条件、弱相容条件和CLR(S,T)性质,证明了两对扩张型自映像的两个新的公共不动点定理.

Endogenous glucocorticoid increases the basal level of Treg-Th17 balance under early phase of stress

Objective： To explore the changes of Treg-Thl 7 balance influenced by corticosterone, major ef- fect hormone ofhypothalamic-pituitary-adrenal （HPA） axis under running stress. Methods： Atotal of 25 corticotropin-releasing hor- mone （CRH） wildtype （CRH＋/＋） and knockout （CRH-/-） mice were adopt and divided into 4 groups as follows： CRH＋/＋ ctrl, CRH＋/＋ stress, CRH-/- ctrl and CRH-/- stress. All mice in stress groups were under 2 h running. After 1 h, blood plasma in all groups was collected and the ex- pression of corticosterone and IL- 17A was detected by ELISA. Meanwhile, unicell suspensions of peripheral lymph node and spleen in each group were prepared too and stained by PE-CD4 and FITC-CD25, then the changes of Treg （CD4＋CD25＋） in different groups were checked by flow cytometry; all data were statistically analyzed by the software of WinMDI 2.9, SPSS 11.5, Origin 7.5 and Matlab 2-D and 3-D plot function. Results： The levels of corticosterone were signifi- cantly higher in stress groups than that in correspond- ing control groups （P〈0.05）, especially in CRH＋/＋ stress group （P〈0.01）. However, the changes of Tregs were not obvious between stress groups and control groups with respective genotypes （P〈0.05）. Compared with that in CRH＋/＋ control group, the ratio of Treg and the expres- sion of IL-17A in CRH-/- stress group were significantly higher than those in control group （P〈0.05）. Combined with the expression levels of corticosterone, Treg and Thl7, our study suggests that endogenous glucocorti- cold with basal level may cause the changes in Treg- Thl7 balance. Moreover, as the corticosterone level increases, the expression of Treg and Thl7 appears to manifest antagonistic fluctuant status with a rising ten- dency in general. Conclusion： Endogenous glucocorticoid under early stage of stress may increase the function of T lymphocyte immunity to some extent.

Identification of a new isoform of the murine Sh2d1a gene and its functional implications

Signaling lymphocytic activation molecule （SLAM）-associated protein （SAP） is a Src homology （SH） domain 2-containing in- tracellular adaptor protein that is predominantly expressed in the hematopoietic system by T lymphocytes and NK cells. SAP protein is encoded by the SH2DIA gene located on the X chromosome. Loss-of-function mutations in SAP cause the X-linked lymphoproliferative disease （XLP）, a severe immunodeficiency characterized by heightened susceptibility to Epstein-Barr vi- rus and impaired humoral immunity. Normal individuals express several functional and non-functional isoforms of SAP as a result of alternative splicing. In this study, we identify a cryptic exon in the murine Sh2dla gene. At the mRNA level, the new isoform of SAP （SAP-2） that includes this new exon is widely expressed in lymphoid tissues by C57BL/6 and 129 strains of inbred mice. SAP-2 accounts for approximately 1%-3% of total SAP transcripts, and it is dynamically regulated during lym- phocyte activation. At the protein level, the SAP-2 isoform is a 144 amino-acid protein. Compared to the dominant 126 ami- no-acid SAP-I isoform, the additional 18 amino acids are inserted into a structural region that is critical for phosphotyrosine binding. Our functional analysis in vitro indicates that SAP-2 is a non-functional isoform due to decreased protein stability. Thus, both human and mouse have multiple SAP splice isoforms that may or may not function. Modulation of relative propor- tions of these isoforms is potentially a mechanism whereby cells can regulate SAP-mediated biological activities.