Indentation size effect of germanium single crystal with different crystal orientations

In order to study the indentation size effect(ISE)of germanium single crystals,nano-indentation experiments were carried out on the(100),(110)and(111)plane-orientated germanium single crystals.The true hardness of each crystal plane of germanium single crystals was calculated based on the Meyer equation,proportional sample resistance(PSR)model and Nix-Gao model,and the indentation size effect(ISE)factor of each crystal plane was calculated.Results show that,the germanium single crystals experience elastic deformation,plastic deformation and brittle fracture during the loading process,and the three crystal planes all show obvious ISE phenomenon.All three models can effectively describe the ISE of germanium single crystals,and the calculated value of Nix-Gao model is the most accurate.Compared with the other two crystal planes,Ge(110)has the highest size effect factor m and the highest hardness,which indicates that Ge(110)has the worst plasticity.

HLA Class I Expressions on Peripheral Blood Mononuclear Cells in Colorectal Cancer Patients

Objective： To investigate the expression change of human leukocyte antigen （HLA） class I on human peripheral blood mononuclear ceils （PBMCs） at both mRNA and protein levels, and to evaluate its roles in the development of colorectal cancer （CRC）. Methods： In the present study, 50 patients with CRC, 35 patients with benign colorectal lesion and 42 healthy volunteers were enrolled. Expression levels of HLA class I mRNA and protein were determined using real-time quantitative reverse transcription PCR （RT-PCR） and flow cytometry analysis, respectively. Results： The expression levels of HLA class I mRNA and proteins were not influenced by age and gender. The relative ratios of HLA class I mRNA were 0.99±0.27 in healthy controls, 0.76±0.19 in benign patients, and 0.48±0.21 in CRC patients. Mean fluorescence intensities of HLA class I were 145.58±38.14 in healthy controls, 102.05±35.98 in benign patients and 87.44±34.01 in CRC patients. HLA class I on PBMCs was significantly down-regulated at both mRNA and protein levels in patients with stage III and IV CRC. CRC patients with lymph node metastasis also showed a decreased HLA class I expression at protein level. Conclusion： HLA class I expressions on PBMCs are associated with staging of CRC and lymph node metastasis. Monitoring the expression of HLA class I on PBMCs may provide useful information for diagnosis and metastasis judgement of CRC.

Novel hybrids of Cu^(2+) ternary complexes of salicylidene-amino acid Schiff base with phenanthroline(or bipyridine) intercalated in Mg/Al-NO_3-layered double hydroxide

Four Cu2＋ complexes of salicylidene-amino acid Schiff base with 1,10-phenanthroline （Phen） or 2,2＇- bipyridine （Bipy） were successfully intercalated in interlayer galleries of Mg/AI-NO3-1ayered double hydroxide （LDH） by the swelling-restored method. The hybrids were characterized by elemental analysis, X-ray diffraction, FT-IR spectra, UV-vis DRS, TG-DTA and SEM observation. Good protection of the complexes by LDH in neutral and weak acidic solutions was revealed by UV spectra, cyclic voltammograms and luminescence spectra.

SYNTHESIS AND CHARACTERIZATION OF COPOLYMERS BASED ON BENZOTHIADIZOLE-THIOPHENE-PHENYLENEVINYLENE

Two novel copolymers based on benzothiadizole-thiophene-phenylenevinylene have been synthesized through palladium catalyzed triple-bond polycondensation method.The copolymers exhibit good solubility in common organic solvents such as CHCl;,CH;Cl;and THF.The structures and properties of the two copolymers are characterized by FT-IR,;H-NMR,UV-Vis absorbance（Abs）,gel permeation chromatography（GPC）,thermal gravimetric analysis and cyclic voltammetry（CV）.The copolymers of P;and P;show absorption spectra with maximum peak at 532 nm and 573 nm in solution,respectively.Compare to their monomers M;and M;,the absorption peaks of P;and P;were red-shifted by 34 nm and 54 nm respectively.Thermal gravimetric analysis demonstrated that the polymers were stable and little weight loss was observed below 300℃.Cyclic voltammetry experiments showed that the band gaps of the copolymers were 1.81 eV and 1.62 eV,respectively,suggesting their potential for applications as organic solar cell materials.