86 research outputs found
Effects of tachyplesin on proliferation and differentiation of human hepatocellular carcinoma SMMC-7721 cells
AIM: To investigate the antitumor activities of tachyplesin on human hepatocellular carcinoma (HCC) cells. METHODS: Tachyplesin, isolated from acid extracts of Chinese horseshoe crab ( Tachypleus tridentatus) hemocytes, was used to treat the human HCC cell line SMMC-7721. Effects of tachyplesin on the proliferation of SMMC-7721 cells were measured with trypan blue dye exclusion test and HE staining. The morphology and ultrastructure of the cells were examined by light microscopy and transmission electron microscopy, respectively. The activities of gamma-glutamyltransferase (gamma-GT) and tyrosine aminotransferase (TAT) were assayed with biochemical methods. The levels of alpha fetoprotein (alpha-FP), proliferating cell nuclear antigen (PCNA), p21(WAF1/CIP1) and c-myc were examined by immunocytochemistry. RESULTS: After treatment with tachyplesin 3.0 mg/L, the proliferation of SMMC-7721 cells was inhibited significantly, with the cell growth inhibitory rate amounted to 55.57% and the maximum cell mitotic index declined by 43.68%. The morphology and ultrastructure underwent restorational alteration. The activity of gamma-GT declined while TAT activity increased obviously, and the levels of alpha-FP and PCNA decreased. Moreover, the expression of p21(WAF1/CIP1) protein was up-regulated and that of c-myc protein was down-regulated. CONCLUSION: Tachyplesin could effectively inhibit the proliferation of hepatocarcinoma cells, reverse the malignant morphological and ultrastructural characteristics, alter the levels of enzymes and antigens, regulate the expression of differentiation-associated oncogene and tumor suppressor gene, and induce hepatocarcinama cell differentiation
Probe R-parity violating stop resonance at the LHeC
We investigate the possibility of detecting single sqaurk production at the
proposed LHeC collider, in the framework of R-parity violating supersymmetry.
Taking advantage of the enhancement of the direct resonance production of
squark and the distinctive kinematics distributions of two body decay final states, the LHeC provides excellent opportunities of
probing R-violating interactions at unprecedented level
compared to all the knowledge derived from indirect low energy nucleon
measurements. If no apparent deviation from SM predictions on high invariant
mass of muon and b-quark final states at the LHeC with 1 data, the
sensitivities on coupling constant can be improved by nearly four orders, at energy
scale about 100 GeV.Comment: 9 pages, 8 figure
A Human-Specific De Novo Protein-Coding Gene Associated with Human Brain Functions
To understand whether any human-specific new genes may be associated with human brain functions, we computationally screened the genetic vulnerable factors identified through Genome-Wide Association Studies and linkage analyses of nicotine addiction and found one human-specific de novo protein-coding gene, FLJ33706 (alternative gene symbol C20orf203). Cross-species analysis revealed interesting evolutionary paths of how this gene had originated from noncoding DNA sequences: insertion of repeat elements especially Alu contributed to the formation of the first coding exon and six standard splice junctions on the branch leading to humans and chimpanzees, and two subsequent substitutions in the human lineage escaped two stop codons and created an open reading frame of 194 amino acids. We experimentally verified FLJ33706's mRNA and protein expression in the brain. Real-Time PCR in multiple tissues demonstrated that FLJ33706 was most abundantly expressed in brain. Human polymorphism data suggested that FLJ33706 encodes a protein under purifying selection. A specifically designed antibody detected its protein expression across human cortex, cerebellum and midbrain. Immunohistochemistry study in normal human brain cortex revealed the localization of FLJ33706 protein in neurons. Elevated expressions of FLJ33706 were detected in Alzheimer's brain samples, suggesting the role of this novel gene in human-specific pathogenesis of Alzheimer's disease. FLJ33706 provided the strongest evidence so far that human-specific de novo genes can have protein-coding potential and differential protein expression, and be involved in human brain functions
Mycobacterium vaccae as Adjuvant Therapy to Anti-Tuberculosis Chemotherapy in Never-Treated Tuberculosis Patients: A Meta-Analysis
OBJECTIVE: To evaluate the effectiveness and safety of heat-killed M. vaccae added to chemotherapy of never-treated tuberculosis (TB) patients. METHODS: The databases of Medline, Embase, Biosis, Cochrane Central Register of Controlled Trials, SCI, CBM, VIP and CNKI were searched. Randomized controlled trials (RCT) and Controlled clinical trials (CCT) comparing M. vaccae with or without a placebo-control injection as adjuvant therapy in the chemotherapy of never-treated TB patients were included. Two reviewers independently performed data extraction and quality assessment. Data were analyzed using RevMan 5.0 software by The Cochrane Collaboration. RESULTS: Fifty four studies were included. At the end of the follow-up period, Pooled RR (Risk Ratio) and its 95% CI of sputum smear conversion rate were 1.07 (1.04, 1.10) in TB patients without complications, 1.17 (0.92, 1.49) in TB patients with diabetes mellitus, 1.02 (0.94, 1.10) in TB patients with hepatitis B, and 1.46 (0.21, 10.06) in TB patients with pneumosilicosis. In elderly TB patients the RR was 1.22 (1.13, 1.32). Analysis of each time point during the follow-up period showed that M. vaccae could help to improve the removal of acid-fast bacilli from the sputum, and promote improvement of radiological focal lesions and cavity closure. Compared with the control group, the differences in levels of immunological indicators of Th1 such as IL-2 and TNF-α were not statistical significant (P = 0.65 and 0.31 respectively), and neither was that of IL-6 produced by Th2 (P = 0.52). An effect of M. vaccae of prevention of liver damage was found in TB patients with hepatitis B (RR 0.20 and 95% CI (0.12, 0.33). No systemic adverse events were reported. CONCLUSION: Added to chemotherapy, M. vaccae is helpful in the treatment of never-treated TB patients in terms of improving both sputum conversion and X-ray appearances
A Policy-Driven Large Scale Ecological Restoration: Quantifying Ecosystem Services Changes in the Loess Plateau of China
As one of the key tools for regulating human-ecosystem relations, environmental conservation policies can promote ecological rehabilitation across a variety of spatiotemporal scales. However, quantifying the ecological effects of such policies at the regional level is difficult. A case study was conducted at the regional level in the ecologically vulnerable region of the Loess Plateau, China, through the use of several methods including the Universal Soil Loss Equation (USLE), hydrological modeling and multivariate analysis. An assessment of the changes over the period of 2000–2008 in four key ecosystem services was undertaken to determine the effects of the Chinese government's ecological rehabilitation initiatives implemented in 1999. These ecosystem services included water regulation, soil conservation, carbon sequestration and grain production. Significant conversions of farmland to woodland and grassland were found to have resulted in enhanced soil conservation and carbon sequestration, but decreased regional water yield under a warming and drying climate trend. The total grain production increased in spite of a significant decline in farmland acreage. These trends have been attributed to the strong socioeconomic incentives embedded in the ecological rehabilitation policy. Although some positive policy results have been achieved over the last decade, large uncertainty remains regarding long-term policy effects on the sustainability of ecological rehabilitation performance and ecosystem service enhancement. To reduce such uncertainty, this study calls for an adaptive management approach to regional ecological rehabilitation policy to be adopted, with a focus on the dynamic interactions between people and their environments in a changing world
Preparation of organo-functionalized mesoporous zeolites supported phosphine-rhodium complex and their catalytic performance for hexene-1 hydroformylation
Organo-functionalized mesoporous zeolites MCM-41 and MCM-48, and amorphous SiO 2 were used as supports to prepare heterogenized phosphine-rhodium complex via anchoring for the hydrofomylation of hexene-1. The supports and the catalysts were characterized by means of XRD, BET, FT-IR and AAS. The MCM-41 and MCM-48 were functionalized with silanes containing (mono-, di-, tri-) amino-, mercapto- and nitrile- groups, respectively, without destruction of the mesoporous structure of the zeolites
Immobilization of rhodium complexes ligated with triphenyphosphine analogs on amino-functionalized MCM-41 and MCM-48 for 1-hexene hydroformylation
Two triphenylphosphine analogs, (4-tert-butylphenyl)diphenylphosphine (1) and bis-(4-tert-butylphenyl)phenylphosphine (2), have been synthesized for the preparation of Rh-P complexes with a formula of Rh(CO)Cl(L)(2) (L stands for the ligands 1 and 2, respectively). Such Rh-P complexes were then attached to amino-group functionalized MCM-41 and MCM-48 for the hydroformylation of 1-hexene in the liquid phase. The supports and the heterogeneous catalysts were characterized by means of XRD, nitrogen adsorption-desorption, FT-IR, HRTEM and AAS. The heterogenized catalysts showed catalytic activity and normal heptanal selectivity comparable to the corresponding homogeneous ones; the advantage in the product selectivity towards the normal heptanal due to the larger cone angle of the ligands over Rh-PPh3 in the homogeneous systems was also observed in the heterogeneous ones. Considerable interactions occurred between the surface amino-groups and the active rhodium species during the immobilization, resulting in highly dispersed active Rh-moieties and a significant modification in the catalytic stability. (C) 2004 Elsevier B.V. All rights reserved
Aqueous phosphine-Rh complexes supported on non-porous fumed-silica nanoparticles for higher olefin hydroformylation
Non-porous fumed-silica nanoparticles were used as supports for the first time to immobilize water-soluble complex HRh(CO)(P(M-C6H4SO3Na)(3) (1) [P(M-C6H4SO3Na)(3), i.e. trisodium salt of tri-(m-sulfophenyl)-phosphine, TPPTS] to obtain supported aqueous-phase catalysts (SAPC) (fumed-SiO2-SAPC) for hydroformylation of 1-hexene. The experimental results proved that the structure of support and the support hydration were the determining factors contributing to the hydroformylation performance. The fumed-SiO2-SAPC where the water-soluble rhodium complexes were well dispersed onto the external surface of the silica nanoparticles presented a higher hydroformylation performance over a relatively wider range of support hydration as compared to the SAPC with conventional porous granular-SiO2 support (porous SiO2-SAPC). A positive effect on the reaction performance was observed from the particle size and surface area of the fumed-silica nanoparticles. The hydroformylation performance with fumed-SiO2-SAPC was promoted by an addition of basic alkali metal salts such as Na2CO3, K2CO3, and NaH2PO4, which depressed the oxidation of ligand TPPTS to OTPPTS [OTPPTS, i.e. trisodium salt of tri-(m-sulfophenyl)-phosphine oxide, OP(M-C6H4SO3Na)(3)] as evidenced by P-31 NMR observation. (C) 2002 Elsevier Science B.V. All rights reserved
Micelle effect of disulfonated cetyldiphenyl phosphine in biphasic hydroformylation of higher olefins
Addition of n-C16H33P(m-C6H4SO3Na)(2)(CDPPDS) to TPPTS-rhodium (TPPTS = P(C6H4-m-SO3Na)(3)) or TPPDS-rhodium (TPPDS = C6H5P(C6H4-m-SO3Na)(2)) hydroformylation catalysts proved to be beneficial both for the reaction rate and normal aldehyde selectivity. Such positive effects were not simply summarized by the results of TPPTS- or TPPDS-rhodium and CDPPDS-rhodium. Emulsion formation was minimized and initial reaction rate went through maximum at the critical micelle concentration (CMC) of CDPPDS. (C) 2004 Elsevier B.V. All rights reserved
Promoting effect of water on 1-hexene hydroformylation catalyzed by aminophosphine-rhodium complexes
Ministry of Science and Technology [2009CB939804]; China Agricultural University [1009071]A series of (o-alkylaminophenyl)diphenylphosphine ligands (P-N ligands) containing different alkyl carbon numbers or amino groups have been synthesized and characterized by IR and NMR ((1)H, (13)C, (31)P). The rhodium complexes ligated with P-N ligands in the hydroformylation of 1-hexene showed a considerable enhancement with the addition of water. NMR characterization studies suggested that the addition of water would engage in hydrogen bonding to the nitrogen atom of the coordinated P-N ligand, inhibiting the internal Rh-N interaction and generating more of the active unsaturated Rh-species that could react with 1-hexene to start the hydroformylation
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