On the mechanism of specific phosphate adsorption by hydroxylated mineral surfaces: A review     

《Communications in Soil Science and Plant Analysis》2012,43(8):801-821

Abstract

The mechanism of specific phosphate adsorption by hydroxy‐lated mineral surfaces comprises two aspects: the phosphate‐hydroxyl surface reaction and the configuration of the adsorbed phosphate ion. Evidence pointing to ligand exchange as the mechanism of the phosphate‐surface hydroxyl reaction include kinetics of adsorption and desorption; hydroxyl ion release; infrared spectroscopy, and stereochemical calculations. Data pertaining to the coordination of adsorbed phosphate on hydroxy‐lated mineral surfaces have not been conclusive overall. Isotopic exchange experiments and studies of desorption kinetics do not provide definitive information on surface coordination. Measurements of hydroxyl ion release and crystallographic calculations provide support for the existence of both monodentate and bidentate surface complexes of phosphate ions. Infrared spectroscopic investigations suggest a binuclear complex on dried, phosphated goethite. However, these studies cannot be extrapolated automatically to soil minerals, since the addition of water favors formation of a monodentate surface complex. Further research is needed to establish the configuration of adsorbed phosphate ions.  相似文献   

Evaluation of circulating PD-1 and PD-L1 as diagnostic biomarkers in dogs with tumors     

Doo-Won Song  Woong-Bin Ro  Hee-Myung Park 《Journal of veterinary science (Suw?n-si, Korea)》2021,22(5)

BackgroundProgrammed cell death protein-1 (PD-1) and programmed cell death ligand-1 (PD-L1) have important roles in tumor evasion of the immune system.ObjectivesThis study aimed to assess the diagnostic utility of circulating PD-1 and PD-L1 levels in healthy dogs and dogs with tumors.MethodsCirculating PD-1 and PD-L1 levels in the serum of 71 dogs with tumors were compared with those of 52 healthy dogs by performing enzyme-linked immunosorbent assay (ELISA).ResultsThe ELISA results revealed higher circulating PD-1 and PD-L1 levels in dogs with tumors (2.9 [2.2–3.7] ng/mL; median [IQR] and 2.4 [1.4–4.4] ng/mL, respectively) than in healthy dogs (2.4 [1.9–3.0] ng/mL; p = 0.012 and 1.4 [0.9–2.1] ng/mL; p < 0.001, respectively). Especially, there was a significant difference in circulating PD-1 levels between healthy dogs and dogs with malignant epithelial tumors (2.4 [1.9–3.0] ng/mL and 3.1 [2.6–4.4] ng/mL, respectively; p < 0.01). In addition, there was a significant difference in circulating PD-L1 levels between healthy dogs and dogs with lymphomas (1.4 [0.9–2.1] ng/mL and 2.7 [1.6–5.8] ng/mL, respectively; p < 0.001).ConclusionThis study indicates that circulating PD-1 and PD-L1 have potential as tumor diagnostic biomarkers in dogs with tumors.  相似文献   

Involvement of the Fas and Fas ligand in testicular germ cell apoptosis by zearalenone in rat   总被引：2，自引：0，他引：2  

Youngheun Jee  Eun-Mi Noh  Eun-Sang Cho  Hwa-Young Son 《Journal of veterinary science (Suw?n-si, Korea)》2010,11(2):115-119

Zearalenone (ZEA), a nonsteroidal estrogenic mycotoxin, is known to cause testicular toxicity in animals. In the present study, the effects of ZEA on spermatogenesis and possible mechanisms involved in germ cell injury were examined in rats. Ten-week-old Sprague-Dawley rats were treated with 5 mg/kg i.p. of ZEA and euthanized 3, 6, 12, 24 or 48 h after treatment. Histopathologically, spermatogonia and spermatocytes were found to be affected selectively. They were TUNEL-positive and found to be primarily in spermatogenic stages I-VI tubules from 6 h after dosing, increasing gradually until 12 h and then gradually decreasing. Western blot analysis revealed an increase in Fas and Fas ligand (Fas-L) protein levels in the ZEA-treated rats. However, the estrogen receptor (ER)α expression was not changed during the study. Collectively, our data suggest that acute exposure of ZEA induces apoptosis in germ cells of male rats and that this toxicity of ZEA is partially mediated through modulation of Fas and Fas-L systems, though ERα may not play a significant role.  相似文献   

Clinical significance of 4-1BBL protein expression in human glioma tissues     

MOU Yong-gao  XIE Hai-tao  PENG Hui  WANG Zhen-ning  WEI Da-nian  ZHANG Xiang-heng  SAI Ke  DENG Xing-hai  ZHANG Guan-hua  CHEN Zhong-ping 《园艺学报》2010,26(12):2342-2346

AIM: To investigate the expression of 4-1BBL(CD137L) protein in human glioma tissues, and to analyze its clinical significance. METHODS: The expression levels of 4-1BBL protein in 82 human glioma specimens were measured by the method of immunohistochemistry. The correlation of 4-1BBL protein level with histopathologic features and survival time was analyzed. RESULTS: 4-1BBL protein positive cells were observed in human brain astrocytic tumors, which were not found in meningioma and normal brain tissues. In our study, the expression of 4-1BBL protein in 3 cases of normal brain tissues was negative. The expression of 4-1BBL protein in 31 cases of glioma specimens were positive, and total positive rate was 37.8% (31/82). The expression of 4-1BBL protein was related to the survival time and age of the patients, but not related to the pathological grade of glioma. Statistically, the patients with positive expression of 4-1BBL protein had longer survival time (P<0.05). CONCLUSION: Expression of 4-1BBL protein may have reference value to predict the prognosis of patients with glioma.  相似文献   

甘草根瘤菌CCNWGX035的抗逆特性及结瘤特征研究   总被引：1，自引：0，他引：1  

WEI Ge-Hong  YANG Xue-Ying  ZHANG Zhi-Xin  YANG Ya-Zhen  K. LINDSR&#;M 《土壤圈》2008,18(1):102-112

Thirty-nine rhizobial isolates were isolated from the root nodules of Glycyrrhiza uralensis and Glyeyrrhiza glabra, growing in the arid and semiarid regions of northwestern China, to test their taxonomic position and stress tolerance and to select one promising putative inoeulant strain for further studies. On the basis of 113 physiological and biochemical characteristics, the isolates were clustered into three groups. One isolate CCNWGX035 was found to have high tolerance to NaC1, pH, and temperature. By sequencing the 16S rDNA, isolate CCNWGX035 was placed in genus Mesorhizobium. Nodulation tests demonstrated that the isolate not only formed nitrogen-fixing nodules on its original host plant Glyeyrrhiza glabra, but also on Sophora vieiifolia, Lotus cornieulatus, Trifolium repens, Melilotus suaveolens, and Sophora alopecuroides. On the basis of sequence analysis of the nodA gene, isolate CCNWGX035 was closely related to strains of the genus Mesorhizobium, exhibiting some novel characteristics of root nodule bacteria.  相似文献   

Selective adsorption of soil humic acid on binary systems containing kaolinite and goethite: Assessment of sorbent interactions     

Hongfeng Chen  Luuk K. Koopal  Jinling Xu  Mingxia Wang  Wenfeng Tan 《European Journal of Soil Science》2019,70(5):1098-1107

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Phosphorus release from vivianite and hydroxyapatite by organic and inorganic compounds     

Stella GYPSER  Dirk FREESE 《土壤圈》2020,30(2):190-200

Based on recent mining rates and the exhaustion of global phosphorus(P)reserves,there is a need to mobilize P already stored in soils,and its recovery from secondary resources such as Ca-and Fe-phosphates is important.The Ca-phosphate hydroxyapatite forms a good fertilizer source,while vivianite is formed in waterlogged soils and sediments.During sludge treatment,the formation of vivianite has been identified,being mainly Fe-phosphate.Long-term P release from both hydroxyapatite and vivianite was studied using different inorganic(CaCl2 and CaSO4)and organic(citric and humic acid)reagents during batch experiments.Reagents CaCl2 and CaSO4 represent the soil solution,while citric and humic acids as organic constituents affect P availability in the rhizosphere and during the process of humification.Additionally,the flow-through reactor(FTR)technique with an infinite sink was used to study the long-term P release kinetics.The cumulative P release was higher by organic acids than by inorganic compounds.The cumulative P release rates were higher in the FTR with CaCl2 as compared to the batch technique.The infinite sink application caused a continuously high concentration gradient between the solid and liquid phases,leading to higher desorption rates as compared to the batch technique.The predominant amount of the total P released over time was available for a short term.While inorganic anion exchange occurred at easily available binding sites,organic acids affected the more heavily available binding sites,which could be embedded within the mineral structure.The results showed that organic compounds,especially citric acid,play a superior role as compared to the inorganic constituents of the soil solution during the recovery of already stored P from the tertiary phosphates vivianite and hydroxyapatite.  相似文献   

鸡三种天然免疫相关受体和配体荧光定量PCR检测方法的建立及应用   总被引：1，自引：0，他引：1  

黄艳艳  高丹丹  许传田  朱曼玲  杨少华  黄庆华  张琳  张秀美  吴家强 《动物医学进展》2016,(4):12-17

为建立检测鸡天然免疫相关受体(Ch-MDA5、Ch-TLR3和Ch-TLR7)及其相应配体(MAVS、TRIF和MyD88)的荧光定量PCR方法并评价其应用效果,设计和筛选特异性PCR引物,制备各基因的质粒标准品,绘制荧光定量PCR的标准曲线,并对方法的灵敏度、重复性和特异性进行检验。结果表明,所建立的检测方法敏感度高、特异性强、检测线性范围广、重复性好。应用建立的方法检测新城疫油乳剂灭活苗免疫SPF鸡后上述基因表达的变化,发现免疫后6h各基因的表达水平达到峰值,表明疫苗免疫迅速有效地激活了机体的天然免疫应答。建立了与鸡抗病毒感染天然免疫相关的3种细胞受体和相应配体的定量检测方法,可应用于病毒致病机制、鸡用新型疫苗、免疫增强剂以及抗病毒药物的研究与开发。  相似文献