Theoretical prediction on room and high temperature mechanical and thermal properties of the matrix and interphase materials for future UHTCf/UHTC composites

Ultrahigh-temperature ceramics (UHTCs) are materials of choice for future hypersonic vehicles as nose tip and sharp leading edges, as well as hot structure components for scramjet engines. However, the brittleness and poor thermal shock resistance are prevailing problems that have blocked the real applications of the current UHTCs. To overcome the brittleness and poor thermal shock resistance, ultrahigh-temperature ceramic fiber reinforced ultrahigh-temperature ceramic matrix (UHTCf/UHTC) composites must be developed. The advantages of future UHTCf/UHTC composites include excellent defect tolerance, high fracture toughness, low density, excellent thermal shock resistance, and high thermal conductivity. Recently, high ceramic yield liquid UHTC precursors and UHTC fibers have been developed, which enable the design and fabrication of UHTCf/UHTC composites utilizing a combined process of CVI and PIP. As for other CMCs, in designing future UHTCf/UHTC composites, fiber–matrix interphase is apt to play a determining role to ensure load transfer, fiber pull-out, and toughening. However, the interphase materials for future UHTCf/UHTC composites are not available yet. In this talk, the room and high temperature mechanical and thermal properties of TMB2 (TM=transition metals) investigated by a combination of first principle and phonon dispersion calculations will be presented first. Then the criteria and methods for searching for the promising interphase materials of UHTCf/UHTC composites including “soft” transition metal borides and borocarbides will be presented. Finally, the chemical bonding nature that underpins the properties of these materials will be discussed. Methods to strengthen the grain boundary of UHTCf will be proposed. And the effect of weak τ bond formed by the overlapping of perpendicular p orbitals on the mechanical properties is emphasized

Normal Red Blood Cell Count Reference Values in Chinese Presenile Women Given by Geographical Area

Background/PurposeWe aimed to standardize the normal reference value of red blood cell (RBC) counts in Chinese presenile women using an underlying scientific basis.MethodsThis research was conducted to study the relationship between the normal reference value of 31,405 RBC samples from presenile women in eight different geographical areas in China. RBC counts were determined using a microscopic counting method.ResultsThere was a significant correlation between geographical factors and the normal reference RBC value in presenile women (F = 187.82, p = 0.000). Using stepwise regression analysis, one regression equation was obtained.ConclusionIf geographical values are obtained in a certain area, the normal RBC reference value in presenile women in this area can be obtained using the regression equation

Effects of a novel pH-sensitive liposome with cleavable esterase-catalyzed and pH-responsive double smart mPEG lipid derivative on ABC phenomenon

Daquan Chen1,2, Wanhui Liu1,2, Yan Shen3, Hongjie Mu1,2, Yanchun Zhang4 , Rongcai Liang1,2, Aiping Wang1,2, Kaoxiang Sun1,2, Fenghua Fu1,2 1School of Pharmacy, Yantai University, Yantai, People’s Republic of China; 2State Key Laboratory of Long-acting and Targeting Drug Delivery System, Yantai, People’s Republic of China; 3College of Pharmacy, China Pharmaceutical University, Nanjing, People’s Republic of China; 4College of Pharmacy, Anhui University of Traditional Chinese Medicine, Hefei, People’s Republic of China Background: The ABC phenomenon is described as a syndrome of accelerated clearance of polyethylene glycol (PEG)-modified liposomes from the bloodstream when repeatedly injected, with their increased accumulation in the liver and spleen. Methods: To clarify this immune response phenomenon, we evaluated a novel modified pH-sensitive liposome with a cleavable double smart PEG-lipid derivative (mPEG-Hz-CHEMS). Results: The ABC phenomenon in mice was brought about by repeated injection of conventional PEG-PE liposomes and was accompanied by a greatly increased uptake in the liver. However, a slight ABC phenomenon was brought about by repeated injection of mPEG-CHEMS liposomes and was accompanied by only a slightly increased uptake in the liver, and repeated injection of mPEG-Hz-CHEMS liposomes did not induce the ABC phenomenon and there was no increase in liver accumulation. This finding indicates that the cleavable mPEG-Hz-CHEMS derivative could lessen or eliminate the ABC phenomenon induced by repeated injection of PEGylated liposomes. Conclusion: This research has shed some light on a solution to the ABC phenomenon using a cleavable PEG-Hz-CHEMS derivative encapsulated in nanoparticles. Keywords: accelerated blood clearance, double smart, cleavable, mPEG-lipid derivates, pH-sensitive liposom

Tumor-Specific Human CD4+ Regulatory T Cells and Their Ligands Implications for Immunotherapy

AbstractRegulatory T cells play an important role in the maintenance of immunological self-tolerance by suppressing immune responses against autoimmune diseases and cancer. Little is known, however, about the nature of the physiological target antigens for CD4+ regulatory T (Treg) cells. Here we report the identification of the LAGE1 protein as a ligand for tumor-specific CD4+ Treg cell clones generated from the tumor-infiltrating lymphocytes (TILs) of cancer patients. Phenotypic and functional analyses demonstrated that they were antigen-specific CD4+ Treg cells expressing CD25 and GITR molecules and possessing suppressive activity on the proliferative response of naive CD4+ T cells to anti-CD3 antibody stimulation. Ligand-specific activation and cell-cell contact were required for TIL102 Treg cells to exert suppressive activity on CD4+ effector cells. These findings suggest that the presence of tumor-specific CD4+ Treg cells at tumor sites may have a profound effect on the inhibition of T cell responses against cancer

First detection of Cryptosporidium spp. in red-bellied tree squirrels (Callosciurus erythraeus) in China

Cryptosporidium spp. are opportunistic pathogens that cause diarrhea in a variety of animal hosts. Although they have been reported in many animals, no information has been published on the occurrence of Cryptosporidium spp. in red-bellied tree squirrels (Callosciurus erythraeus). A total of 287 fecal specimens were collected from Sichuan province in China; the prevalence of Cryptosporidium spp., measured by nested-PCR amplification of the partial small-subunit (SSU) rRNA gene, was 1.4% (4/287). Three different Cryptosporidium species or genotypes were identified: Cryptosporidium parvum (n = 1), Cryptosporidium wrairi (n = 1), and Cryptosporidium rat genotype II (n = 2). The present study is the first report of Cryptosporidium infection in red-bellied tree squirrels in China. Although there is a relatively low occurrence of Cryptosporidium, the presence of C. parvum and C. wrairi, which were previously reported in humans, indicates that red-bellied tree squirrels may be a source of zoonotic cryptosporidiosis in China

TELEX HEBDOMADAIRE NR 95 DU 17.09.82 DESTINE A L'ENSEMBLE DES DELEGATIONS EXTERIEURES ET BUREAUX DE PRESS ET D'INFORMATION INDEPENDANTS DANS LES PAYS TIERS = WEEKLY MEMO NO. 95 FOR 17.09.82 TO FOREIGN DELEGATIONS AND PRESS BUREAUS OF THIRD COUNTRIES

<p>High-performance liquid chromatography (HPLC) results of (A) commercial surfactin sample, and (B) our extract surfactin of <i>B</i>. <i>subtilis</i> HH2 in LB medium. There were three main peaks (Peak A-C) of the extract and the surfactin standard in the same location.</p