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Ruan D, Jiang SQ, Hu YJ, Ding FY, Fan QL, Chen F, Lin XJ, Li L, Wang Y. Effects of corn distillers dried grains with solubles on performance, oxidative status, intestinal immunity and meat quality of Chinese Yellow broilers. J Anim Physiol Anim Nutr (Berl) 2017; 101:1185-1193. [PMID: 28066935 DOI: 10.1111/jpn.12637] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 10/12/2016] [Indexed: 11/29/2022]
Abstract
The study assessed the effects of different dietary levels of corn distillers dried grains with solubles (DDGS) on performance, oxidation status, intestinal immunity and meat quality in Chinese Yellow broilers aged from 1 to 63 days. Lingnan male hatchings (1440) were randomly assigned to six treatments, each consisting of six replicates of 40 birds. The basal diet (I) was a typical corn-soya bean ration while the experimental diets (II to VI) partially substituted corn DDGS for soya bean meal. The level of substitution in starter, grower and finisher diets was as follows: II, 2%, 4% then 6%; III, 4%, 8% then 12%; IV, 6%, 12% then 18%; V, 8%, 16% then 24%; VI, 10%, 20% then 30%. Average daily feed intake and feed-to-gain ratio increased as linear responses to corn DDGS substitution from 1 to 21 days (p < 0.001). The plasma content of triglycerides and liver content of malondialdehyde increased as linear responses to corn DDGS substitution (p < 0.05). There was a linear decrease (p < 0.001) in jejunal abundance of IL-6 transcripts, with a substantial reduction to approximately 25% those of broilers fed the control diet, and a quadratic effect existed for secretory immunoglobulin A (sIgA) (p < 0.001). In addition, increased dietary corn DDGS caused favourable changes in selected functional properties of the meat: drip loss at 24 and 96 h increased as linear response to corn DDGS substitution (p < 0.001). Further, meat colour L* values decreased and a* values increased linearly in response to increasing corn DDGS (p < 0.05). In conclusion, diet IV (6%, 12% then 18% corn DDGS) in Chinese Yellow broiler diets had no negative effects on performance, antioxidant capacity and meat quality. This level of inclusion also appeared to promote sIgA secretion and enhance anti-inflammatory status.
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Wei FL, Wang JH, Ding G, Yang SY, Li Y, Hu YJ, Wang SL. Mechanical force-induced specific MicroRNA expression in human periodontal ligament stem cells. Cells Tissues Organs 2015; 199:353-63. [PMID: 25823370 DOI: 10.1159/000369613] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/06/2014] [Indexed: 01/14/2023] Open
Abstract
It remains unclear how the expression of microRNAs (miRNAs) in human periodontal ligament stem cells (PDLSCs) might respond to mechanical stretch. To investigate specific miRNA expression in stretched PDLSCs, we used a Flexcell® FX-5000™ tension system to achieve external mechanical stimulation. Then, a custom-designed microarray assay was performed to investigate and describe the genome-wide differential expression of miRNAs in normal and stretched PDLSCs. Finally, we implemented integrative miRNA target prediction and network analysis approaches to construct an interaction network of the key miRNAs and their putative targets. We found that stretching induced morphological changes and increased alkaline phosphatase (ALP) activity, runt-related transcription factor 2 (RUNX2), osteocalcin (OCN), and bone sialoprotein (BSP) expression in PDLSCs. The microarray data showed that 53 miRNAs were differentially expressed with stretching. With an interaction network, we examined the connections between 10 selected key miRNAs and their putative target genes, which were related to mechanical force. The results from the interaction network provided a basis for postulating the functional roles of miRNAs in PDLSCs.
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Hu YJ, Lin DY, Sun W, Zeng D. A Likelihood-Based Framework for Association Analysis of Allele-Specific Copy Numbers. J Am Stat Assoc 2015; 109:1533-1545. [PMID: 25663726 DOI: 10.1080/01621459.2014.908777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Copy number variants (CNVs) and single nucleotide polymorphisms (SNPs) co-exist throughout the human genome and jointly contribute to phenotypic variations. Thus, it is desirable to consider both types of variants, as characterized by allele-specific copy numbers (ASCNs), in association studies of complex human diseases. Current SNP genotyping technologies capture the CNV and SNP information simultaneously via fluorescent intensity measurements. The common practice of calling ASCNs from the intensity measurements and then using the ASCN calls in downstream association analysis has important limitations. First, the association tests are prone to false-positive findings when differential measurement errors between cases and controls arise from differences in DNA quality or handling. Second, the uncertainties in the ASCN calls are ignored. We present a general framework for the integrated analysis of CNVs and SNPs, including the analysis of total copy numbers as a special case. Our approach combines the ASCN calling and the association analysis into a single step while allowing for differential measurement errors. We construct likelihood functions that properly account for case-control sampling and measurement errors. We establish the asymptotic properties of the maximum likelihood estimators and develop EM algorithms to implement the corresponding inference procedures. The advantages of the proposed methods over the existing ones are demonstrated through realistic simulation studies and an application to a genome-wide association study of schizophrenia. Extensions to next-generation sequencing data are discussed.
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Tao Y, Lin J, Hu YJ, Zhou B, Zhu BQ. Development of a quantitative ELISA kit for human secreted CD306/LAIR-2 and its application. Chin J Nat Med 2014; 12:847-52. [PMID: 25480516 DOI: 10.1016/s1875-5364(14)60127-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Indexed: 10/24/2022]
Abstract
AIM A quantitative ELISA kit for the detection of human secreted CD306/LAIR-2 was developed using monoclonal and polyclonal antibodies which were raised against a highly purified recombinant human secreted CD306/LAIR-2. METHODS Anti-human secreted CD306/LAIR-2 monoclonal and polyclonal antibodies were raised by immunizing mouse or rabbit with recombinant human secreted CD306/LAIR-2. The monoclonal antibody was purified by protein G affinity, whereas the polyclonal antibody was purified by protein A affinity. The best match pair of antibodies were found and used to develop a double antibody sandwich ELISA kit for the detection of human secreted CD306/LAIR-2 in human samples. RESULTS A human secreted CD306/LAIR-2 ELISA kit was formulated with highly purified recombinant human secreted CD306/LAIR-2, highly specific monoclonal and polyclonal antibodies. This kit realized the quantitative measurement of recombinant human CD306/LAIR-2 and natural CD306/LAIR-2 in human serum samples. CONCLUSIONS The developed human secreted CD306/LAIR-2 ELISA kit is a reliable quantitation immunoassay kit.
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Fu HB, Shang GF, Lin J, Hu YJ, Hu QQ, Guo L, Zhang YC, Chen JM. Fractional iron solubility of aerosol particles enhanced by biomass burning and ship emission in Shanghai, East China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 481:377-391. [PMID: 24607631 DOI: 10.1016/j.scitotenv.2014.01.118] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 01/27/2014] [Accepted: 01/28/2014] [Indexed: 06/03/2023]
Abstract
In terms of understanding Fe mobilization from aerosol particles in East China, the PM2.5 particles were collected in spring at Shanghai. Combined with the backtrajectory analysis, the PM2.5/PM10 and Ca/Al ratios, a serious dust-storm episode (DSE) during the sampling was identified. The single-particle analysis showed that the major iron-bearing class is the aluminosilicate dust during DSE, while the Fe-bearing aerosols are dominated by coal fly ash, followed by a minority of iron oxides during the non-dust storm days (NDS). Chemical analyses of samples showed that the fractional Fe solubility (%FeS) is much higher during NDS than that during DSE, and a strong inverse relationship of R(2)=0.967 between %FeS and total atmospheric iron loading were found, suggested that total Fe (FeT) is not controlling soluble Fe (FeS) during the sampling. Furthermore, no relationship between FeS and any of acidic species was established, suggesting that acidic process on aerosol surfaces are not involved in the trend of iron solubility. It was thus proposed that the source-dependent composition of aerosol particles is a primary determinant for %FeS. Specially, the Al/Fe ratio is poorly correlated (R(2)=0.113) with %FeS, while the apparent relationship between %FeS and the calculated KBB(+)/Fe ratio (R(2)=0.888) and the V/Fe ratio (R(2)=0.736) were observed, reflecting that %FeS could be controlled by both biomass burning and oil ash from ship emission, rather than mineral particles and coal fly ash, although the latter two are the main contributors to the atmospheric Fe loading during the sampling. Such information can be useful improving our understanding on iron solubility on East China, which may further correlate with iron bioavailability to the ocean, as well as human health effects associated with exposure to fine Fe-rich particles in densely populated metropolis in China.
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Hu YJ, Zhu BQ. [Research progress on strain improvement of Acremonium chrysogenum by genetic engineering]. YI CHUAN = HEREDITAS 2011; 33:1079-1086. [PMID: 21993282 DOI: 10.3724/sp.j.1005.2011.01079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Acremonium chrysogenum, cephalosporin C (CPC) producing strain, is an important industrial microorganism. CPC is used to produce 7-ACA, a major intermediate for manufacturing of many first-line anti-infectious cephalosporin-antibiotics. The fermentation level of CPC determines the production, quality and cost of its downstream products. Therefore, it is necessary to develop the strains of A. chrysogenum. Along with the development of molecular biology, genetic manipulation technique is becoming more and more important in the field of molecular breeding. This paper reviews the latest research progresses on CPC biosynthesis and its regulation. Genetic manipulations of A. chrysogenum were summarized and concluded. We suggested that strain improvement of A. chrysogenum by means of induction and expression of biosynthetic and regulatory genes, as well as exogenous genes, and further optimization could be applied to different aspects including CPC production enhancement and metabolic pathway elongation, etc. Future direction of this field is also proposed. We believed that incorporation of comparative proteomics and genomic shuffling with molecular breeding could lead the achievements close to industry promptly.
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Zhou YQ, Wang XH, Hong GH, Zhu Y, Zhang XQ, Hu YJ, Mao Q. Twenty-four weeks of pegylated interferon plus ribavirin effectively treat patients with HCV genotype 6a. J Viral Hepat 2011; 18:595-600. [PMID: 21105968 DOI: 10.1111/j.1365-2893.2010.01373.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The optimal duration of treatment and expected response rate for hepatitis C virus genotype (HCV-6)-infected patients have not been determined. Our aims were to determine the treatment outcome with pegylated interferon (PEG-IFN) plus ribavirin for HCV-6a-infected patients at Southwest Hospital and assess the association of the on-treatment virological response with the sustained virological response (SVR). Medical records were reviewed retrospectively. Twenty-two HCV-6a-infected patients were treated for 24 weeks, and 21 (95.5%) achieved an early virological response (EVR), 20 (90.9%) an end-of-treatment response (ETR) and 18 (81.8%) a SVR. However, only 18 of the 22 HCV-6a-infected patients were tested for serum HCV RNA level at week 4 of treatment and 15 (83.3%) achieved a rapid virological response (RVR). The rates of SVR, RVR, EVR and ETR in these patients were all similar to those in HCV-2/3 treated for 24 weeks and higher than those in HCV-1b-infected patients treated for 48 weeks. A lower relapse rate (10.0%) was seen in HCV-6a compared with HCV-2/3 (12.5%) or HCV-1b-infected patients (23.3%). The positive predictive values of RVR and EVR for HCV-6a were comparable with those for HCV-2/3-infected patients (86.7%vs 90.9%, P = 0.683 and 85.7%vs 86.8%, P = 0.904, respectively). Of the 3 HCV-6a-infected patients who did not achieve a RVR, 2 achieved an EVR and went on to achieve a SVR. The patient who did not achieve an EVR did not achieve a SVR. In summary, our results indicate that 24 weeks of PEG-IFN plus ribavirin can effectively treat patients with HCV-6a chronic infection.
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Abstract
Analysis of untyped single nucleotide polymorphisms (SNPs) can facilitate the localization of disease-causing variants and permit meta-analysis of association studies with different genotyping platforms. We present two approaches for using the linkage disequilibrium structure of an external reference panel to infer the unknown value of an untyped SNP from the observed genotypes of typed SNPs. The maximum-likelihood approach integrates the prediction of untyped genotypes and estimation of association parameters into a single framework and yields consistent and efficient estimators of genetic effects and gene-environment interactions with proper variance estimators. The imputation approach is a two-stage strategy, which first imputes the untyped genotypes by either the most likely genotypes or the expected genotype counts and then uses the imputed values in a downstream association analysis. The latter approach has proper control of type I error in single-SNP tests with possible covariate adjustments even when the reference panel is misspecified; however, type I error may not be properly controlled in testing multiple-SNP effects or gene-environment interactions. In general, imputation yields biased estimators of genetic effects and gene-environment interactions, and the variances are underestimated. We conduct extensive simulation studies to compare the bias, type I error, power, and confidence interval coverage between the maximum likelihood and imputation approaches in the analysis of single-SNP effects, multiple-SNP effects, and gene-environment interactions under cross-sectional and case-control designs. In addition, we provide an illustration with genome-wide data from the Wellcome Trust Case-Control Consortium (WTCCC) [2007].
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Chu CM, Rasalkar DD, Hu YJ, Cheng FWT, Li CK, Chu WCW. Clinical presentations and imaging findings of neuroblastoma beyond abdominal mass and a review of imaging algorithm. Br J Radiol 2011; 84:81-91. [PMID: 21172969 DOI: 10.1259/bjr/31861984] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Neuroblastoma is one of the most common malignant neoplasms in childhood. The most common clinical presentation of this tumour is abdominal mass. However, affected children may have various clinical presentations as a result of disseminated metastatic disease or associated paraneoplastic syndromes at the time of diagnosis. In this article we have outlined the imaging findings in seven patients with "extra-abdominal" presentation of neuroblastoma and the pitfalls in making the correct diagnosis. The purpose of this pictorial review is to alert the general radiologist to the possible presentations of this common childhood malignancy to derive early detection and diagnosis.
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Hu YJ, Lin DY, Zeng D. A general framework for studying genetic effects and gene-environment interactions with missing data. Biostatistics 2010; 11:583-98. [PMID: 20348396 DOI: 10.1093/biostatistics/kxq015] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Missing data arise in genetic association studies when genotypes are unknown or when haplotypes are of direct interest. We provide a general likelihood-based framework for making inference on genetic effects and gene-environment interactions with such missing data. We allow genetic and environmental variables to be correlated while leaving the distribution of environmental variables completely unspecified. We consider 3 major study designs-cross-sectional, case-control, and cohort designs-and construct appropriate likelihood functions for all common phenotypes (e.g. case-control status, quantitative traits, and potentially censored ages at onset of disease). The likelihood functions involve both finite- and infinite-dimensional parameters. The maximum likelihood estimators are shown to be consistent, asymptotically normal, and asymptotically efficient. Expectation-Maximization (EM) algorithms are developed to implement the corresponding inference procedures. Extensive simulation studies demonstrate that the proposed inferential and numerical methods perform well in practical settings. Illustration with a genome-wide association study of lung cancer is provided.
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Woo KS, Chook P, Yip TWC, Kwong SK, Hu YJ, Huang XS, Wu MJ, Liu YM, Lam CWK, Celermajer DS. FOLIC ACID AND VITAMIN B-12 SUPPLEMENTATION IMPROVES ARTERIAL FUNCTION AND STRUCTURE IN SUBJECTS WITH SUBNORMAL INTAKE. Heart Lung Circ 2008. [DOI: 10.1016/j.hlc.2008.03.077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Hu YJ, Hardianto A, Li SY, Zhang ZY, Zhang CP. Reconstruction of a palatomaxillary defect with vascularized iliac bone combined with a superficial inferior epigastric artery flap and zygomatic implants as anchorage. Int J Oral Maxillofac Surg 2007; 36:854-7. [PMID: 17616341 DOI: 10.1016/j.ijom.2007.04.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2005] [Revised: 07/27/2006] [Accepted: 04/27/2007] [Indexed: 10/23/2022]
Abstract
Here is described a modified technique of palatomaxillary reconstruction that combines the use of a free vascularized bone graft by osteotomy, soft-tissue flap, zygomatic implant as an anchorage and two standard implants simultaneously. The patient presented with deformity in the left face after subtotal maxillectomy (Brown 2b classification). Preoperative work up was performed by a rapid prototyping model using computer-aided manufacturing technology. The purpose of this model is to provide accurate measurements of the defect. The palatomaxillary three-dimensional buttress system can be managed by orienting the bone graft vertically and horizontally. Reconstruction of the palatomaxillary defect was successfully accomplished in a single surgical procedure. Dental implant restoration achieved good osseointegration without any significant resorption. This new modification represents a significant contribution to palatomaxillary reconstruction using zygomatic implants as anchorage.
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Zheng JW, Zhong LP, Zhang ZY, Zhang CP, Zhu HG, Sun J, Fan XD, Hu YJ, Ye WM, Li J, Suen J. Carotid artery resection and reconstruction: clinical experience of 28 consecutive cases. Int J Oral Maxillofac Surg 2007; 36:514-21. [PMID: 17339099 DOI: 10.1016/j.ijom.2007.01.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Revised: 12/09/2006] [Accepted: 01/11/2007] [Indexed: 01/06/2023]
Abstract
The aim of this study was to analyse the experience at a single institution in carotid artery resection with or without reconstruction performed as part of an oncological procedure or emergency haemostasis. A total of 28 patients were included in this retrospective study; 17 underwent ligation or resection of the carotid artery, and 11 underwent reconstruction of the carotid artery. The perioperative complications and surgical outcomes were recorded and analysed. Of the 17 patients with ligation or resection of the carotid artery, 4 developed neurologic deficit within 2 weeks postoperatively. Three patients with malignant tumours died 1 month (1) and 4 months (2) postoperatively. Of the 11 patients undergoing carotid reconstruction, no major cerebral complications were noted after operation. Colour Doppler showed patent vascular graft 1 year postoperatively in nine patients. Due to the higher complication rates both in short and long term with ligation or resection of the carotid artery, resection and revascularization of the carotid artery is advocated for patients with carotid artery involvement when possible.
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Hu YJ, Fu HB, Bernstein ER. IR plus vacuum ultraviolet spectroscopy of neutral and ionic organic acid monomers and clusters: Propanoic acid. J Chem Phys 2006; 125:184309. [PMID: 17115754 DOI: 10.1063/1.2378628] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The vibrational spectrum of molecular propanoic acid, cooled in a supersonic expansion, in the region of 2500 to 7500 cm(-1) is obtained employing infrared plus vacuum ultraviolet nonresonant ionization detected spectroscopy. The fundamental and first overtone of the CH and OH stretch modes of cold propanoic acid molecules can be identified in the spectrum. Propanoic acid neutral and ionic clusters are also studied employing nonresonant ion dip and photodissociation spectroscopic techniques, respectively. For the neutral dimer, a sequence of features observed at ca. 2500-2700 cm(-1) can be assigned as combination bands of low frequency modes with the COH bending overtone; these features characterize the cyclic dimer ring structure. IR spectra of the larger neutral clusters n=3, 4, 5 indicate that they also have cyclic structures in which the OH groups are engaged in the cluster hydrogen bonding network. The CH groups are not involved in this hydrogen bonding structure. Free OH features are observed for the protonated ion clusters (C(2)H(5)COOH)(n)H(+), n=1,...,5, indicating that at least one OH group of these cluster ions is not involved in the cluster hydrogen bonding network. A comparison of the results for four hydrogen bonding neutral and ionic clusters (CH(3)OH, C(2)H(5)OH, CH(3)COOH, and C(2)H(5)COOH) is presented and discussed.
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Hu YJ, Fu HB, Bernstein ER. IR plus vacuum ultraviolet spectroscopy of neutral and ionic organic acid molecules and clusters: Acetic acid. J Chem Phys 2006; 125:184308. [PMID: 17115753 DOI: 10.1063/1.2378626] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Infrared (IR) vibrational spectroscopy of acetic acid (A) neutral and ionic monomers and clusters, employing vacuum ultraviolet (VUV), 10.5 eV single photon ionization of supersonically expanded and cooled acetic acid samples, is presented and discussed. Molecular and cluster species are identified by time of flight mass spectroscopy: the major mass features observed are A(n)H(+) (n=1-9), ACOOH(+) (VUV ionization) without IR radiation present, and A(+) with both IR and VUV radiation present. The intense feature ACOOH(+) arises from the cleavage of (A)(2) at the beta-CC bond to generate ACOOH(+)+CH(3) following ionization. The vibrational spectrum of monomeric acetic acid (2500-7500 cm(-1)) is measured by nonresonant ionization detected infrared (NRID-IR) spectroscopy. The fundamentals and overtones of the CH and OH stretches and some combination bands are identified in the spectrum. Mass selected IR spectra of neutral and cationic acetic acid clusters are measured in the 2500-3800 cm(-1) range employing nonresonant ionization dip-IR and IR photodissociation (IRPD) spectroscopies, respectively. Characteristic bands observed at approximately 2500-2900 cm(-1) for the cyclic ring dimer are identified and tentatively assigned. For large neutral acetic acid clusters A(n)(n>2), spectra display only hydrogen bonded OH stretch features, while the CH modes (2500-2900 cm(-1)) do not change with cluster size n. The IRPD spectra of protonated (cationic) acetic acid clusters A(n)H(+) (n=1-7) exhibit a blueshift of the free OH stretch with increasing n. These bands finally disappear for n> or =6, and one broad and weak band due to hydrogen bonded OH stretch vibrations at approximately 3350 cm(-1) is detected. These results indicate that at least one OH group is not involved in the hydrogen bonding network for the smaller (n< or =5) A(n)H(+) species. The disappearance of the free OH stretch feature at n> or =6 suggests that closed cyclic structures form for A(n)H(+) for the larger clusters (n> or =6).
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Hu YJ, Fu HB, Bernstein ER. Infrared plus vacuum ultraviolet spectroscopy of neutral and ionic methanol monomers and clusters: New experimental results. J Chem Phys 2006; 125:154306. [PMID: 17059254 DOI: 10.1063/1.2357953] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
We present new observations of the infrared (IR) spectrum of neutral methanol and neutral and protonated methanol clusters employing IR plus vacuum ultraviolet (vuv) spectroscopic techniques. The tunable IR light covers the energy ranges of 2500-4500 cm(-1) and 5000-7500 cm(-1). The CH and OH fundamental stretch modes, the OH overtone mode, and combination bands are identified in the vibrational spectrum of supersonic expansion cooled methanol (2500-7500 cm(-1)). Cluster size selected IR plus vuv nonresonant infrared ion-dip infrared spectra of neutral methanol clusters, (CH(3)OH)(n) (n=2,[ellipsis (horizontal)],8), demonstrate that the methanol dimer has free and bonded OH stretch features, while clusters larger than the dimer display only hydrogen bonded OH stretch features. CH stretch mode spectra do not change with cluster size. These results suggest that all clusters larger than the dimer have a cyclic structure with OH groups involved in hydrogen bonding. CH groups are apparently not part of this cyclic binding network. Studies of protonated methanol cluster ions (CH(3)OH)(n)H(+) n=1,[ellipsis (horizontal)],7 are performed by size selected vuv plus IR photodissociation spectroscopy in the OH and CH stretch regions. Energies of the free and hydrogen bonded OH stretches exhibit blueshifts with increasing n, and these two modes converge to approximately 3670 and 3400 cm(-1) at cluster size n=7, respectively.
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Hu YJ, Fu HB, Bernstein ER. Infrared plus vacuum ultraviolet spectroscopy of neutral and ionic ethanol monomers and clusters. J Chem Phys 2006; 125:154305. [PMID: 17059253 DOI: 10.1063/1.2357952] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
A high sensitivity spectroscopy is employed to detect vibrational antiitions of ethanol neutrals and ions in a supersonic expansion. The infrared (IR) features located at 3682 and 3667 cm(-1) can be assigned to the OH stretch for the two neutral C(2)H(5)OH conformers, anti and gauche, respectively. Their overtone energies located at 7179 (anti) and 7141 (gauche) cm(-1) are also identified. The OH fundamental stretch for ethanol ions is redshifted around 210 cm(-1), while the CH stretch modes are unchanged for neutral and ionic C(2)H(5)OH at around 2900-3000 cm(-1). The charge on the ethanol ion is apparently localized on the oxygen atom. IR induced photodissociation spectroscopy is applied to the study of neutral and protonated ethanol clusters. Neutral and protonated ethanol cluster vibrations are observed. The CH modes are not perturbed by the clustering process. Neutral clusters display only hydrogen bonded OH features, while the protonated ionic clusters display both hydrogen bonded and non-hydrogen-bonded features. These spectroscopic results are analyzed to obtain qualitative structural information on neutral and ionic ethanol clusters.
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Fu HB, Hu YJ, Bernstein ER. Generation and detection of alkyl peroxy radicals in a supersonic jet expansion. J Chem Phys 2006; 125:014310. [PMID: 16863301 DOI: 10.1063/1.2209680] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Alkyl peroxy radicals are synthesized in a supersonic jet expansion by the initial production of alkyl radicals and subsequent reaction with molecular oxygen. Parent ions CH3OO+/CD3OO+ are observed employing vacuum ultraviolet (VUV) single photon ionizationtime-of-flight mass spectroscopy (TOFMS). Employing infrared (IR) + VUV photofragmentation detected spectroscopy, rotationally resolved infrared spectra of jet-cooled CH3OO and CD3OO radicals are recorded for the A 2A' <-- X 2A" transition by scanning the IR laser frequency while monitoring the CH3 + and CD3 + ion signals generated by the VUV laser. The band origins of the A 2A'<--X 2A" transition for CH3OO and CD3OO are identified at 7381 and 7371 cm(-1), respectively. Rotational simulation for the CH3OO and CD3OO 0(0) 0 transitions of A<--X yields a rotational temperature for these radicals of approximately 30 K. With the aid of ab initio calculations, two and five vibrational modes for the A 2A' excited electronic state are assigned for CH3OO and CD3OO radicals, respectively. Both experimental and theoretical results suggest that the ground electronic state of the ions of ethyl and propyl peroxy radicals are not stable although their ionization energies (IE) are less than 10.5 eV. The C2H5OO+/C3H7OO+ cations can readily decompose to C2H5 +/C3H7 + and O2. This is partially responsible for the inability of IR+VUV photofragmentation spectroscopy to detect the near IR A<--X electronic transition for these radicals.
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Hu YJ, Fu HB, Bernstein ER. Vibronic spectroscopy of the peroxyacetyl radical in the near IR. J Chem Phys 2006; 124:114305. [PMID: 16555886 DOI: 10.1063/1.2179428] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The A 2A'<--X 2A" electronic transition of the peroxyacetyl radical (PA) is observed employing NIR/VUV ion enhancement, supersonic jet spectroscopy. Rotational envelope simulations yield a rotational temperature for ground state PA of ca. 55 K. Ab initio calculations of transition energies and vibrational frequencies for the A<--X transition assist in the assignment of the observed spectrum. A number of the vibrational modes of the A state are assigned to observed transitions (the O-O stretch 2(1), the COO bend 5(1), and the CCOO backbone bend 6(1)). The calculations and mass spectra suggest that the ground state of the PA ion is repulsive. An increase in rotational linewidth of the overtone of the O-O stretch (2(1)) is observed and discussed in terms of A state dynamics. The O-O stretch anharmonicity is estimated to be 13.35 cm(-1).
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Hu YJ, Fu HB, Bernstein ER. Generation and Detection of the Peroxyacetyl Radical in the Pyrolysis of Peroxyacetyl Nitrate in a Supersonic Expansion. J Phys Chem A 2006; 110:2629-33. [PMID: 16494372 DOI: 10.1021/jp058196i] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The peroxyacetyl radical (PA, CH3C(O)OO) is generated by flash pyrolysis of peroxyacetyl nitrate (PAN, CH3C(O)OONO2) in a supersonic jet. The 0(0)(0) A2A' <-- X2A'' electronic transition for PA, at ca. 5582 cm(-1), is detected in a supersonically cooled sample by time-of-flight mass spectroscopy in the CH3CO mass channel. Rotational envelope simulation results find that the rotational temperature for PA in its ground electronic and vibrational state is ca. 55 K. At ca. 330 degrees C, the thermal decomposition of PAN by flash pyrolysis in a heated nozzle with supersonic expansion is mainly by formation of PA and NO2. The maximum yield of PA is obtained at this temperature. At higher temperatures (300-550 degrees C), an intense signal in the CH2CO+ mass channel is observed, generated by the decomposition of PA.
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Fu HB, Hu YJ, Bernstein ER. IR+vacuum ultraviolet (118 nm) nonresonant ionization spectroscopy of methanol monomers and clusters: Neutral cluster distribution and size-specific detection of the OH stretch vibrations. J Chem Phys 2006; 124:024302. [PMID: 16422578 DOI: 10.1063/1.2141951] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Small methanol clusters are formed by expanding a mixture of methanol vapor seeded in helium and are detected using vacuum UV (vuv) (118 nm) single-photon ionization/linear time-of-flight mass spectrometer (TOFMS). Protonated cluster ions, (CH3OH)(n-1)H+ (n=2-8), formed through intracluster ion-molecule reactions following ionization, essentially correlate to the neutral clusters, (CH3OH)n, in the present study using 118 nm light as the ionization source. Both experimental and Born-Haber calculational results clarify that not enough excess energy is released into protonated cluster ions to initiate further fragmentation in the time scale appropriate for linear TOFMS. Size-specific spectra for (CH3OH)n (n=4 to 8) clusters in the OH stretch fundamental region are recorded by IR+vuv (118 nm) nonresonant ion-dip spectroscopy through the detection chain of IR multiphoton predissociation and subsequent vuv single-photon ionization. The general structures and gross features of these cluster spectra are consistent with previous theoretical calculations. The lowest-energy peak contributed to each cluster spectrum is redshifted with increasing cluster size from n=4 to 8, and limits near approximately 3220 cm(-1) in the heptamer and octamer. Moreover, IR+vuv nonresonant ionization detected spectroscopy is employed to study the OH stretch first overtone of the methanol monomer. The rotational temperature of the clusters is estimated to be at least 50 K based on the simulation of the monomer rotational envelope under clustering conditions.
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Fu HB, Hu YJ, Bernstein ER. IR/UV double resonant spectroscopy of the methyl radical: Determination of ν3 in the 3pz Rydberg state. J Chem Phys 2005; 123:234307. [PMID: 16392920 DOI: 10.1063/1.2135772] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
IR+UV double resonant ion-dip and ion-enhancement spectroscopies are employed to study the nu3 asymmetric CH stretch vibration fundamental of CH3 in the ground and 3p(z) Rydberg electronic states. CH3 radical is synthesized in the supersonic jet expansion by flash pyrolysis of azomethane (CH3NNCH3) prior to the expansion. The Q band of the 3(1) (1) 3p(z)<--X transition of CH3, not detected by conventional UV resonantly enhanced multiphoton ionization (REMPI) spectroscopy, is determined to lie at 59,898 cm(-1) using IR+UV REMPI spectroscopy. Energy of the asymmetric CH stretch of CH3 in the 3p(z) Rydberg state, nu3(3p(z)), is 3087 cm(-1), redshifted by approximately 74 cm(-1) with respect to ground state nu3(X).
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Weng YB, Hu YJ, Li Y, Li BS, Lin RQ, Xie DH, Gasser RB, Zhu XQ. Survey of intestinal parasites in pigs from intensive farms in Guangdong Province, People's Republic of China. Vet Parasitol 2004; 127:333-6. [PMID: 15710534 DOI: 10.1016/j.vetpar.2004.09.030] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2004] [Revised: 08/31/2004] [Accepted: 09/14/2004] [Indexed: 11/19/2022]
Abstract
The prevalence of intestinal parasites was investigated in intensive pig farms in Guangdong Province, China between July 2000 and July 2002. Faecal samples from 3636 pigs (both sexes and five age groups) from 38 representative intensive pig farms employing different parasite control strategies were examined for the presence of helminth ova and protozoan oocysts, cysts and/or trophozoites using standard techniques. Of the 3636 pigs sampled, 209 (5.7%) were infected with Trichuris suis, 189 (5.2%) with Ascaris, 91 (2.5%) with Oesophagostomum spp., 905 (24.9%) with coccidia (Eimeria spp. and/or Isospora suis) and 1716 (47.2%) with Balantidium coli. These infected pigs were mainly from farms without a strategic anti-parasite treatment regime. Concurrent infection of multiple parasites was common, and T. suis was the most common nematode infecting breeding, young and mature pigs. The results of the present investigation provide relevant 'base-line' data for assessing the effectiveness of control strategies against intestinal parasitism in intensively raised pigs in Guangdong Province, China.
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Hu YJ, Zang L, Wu YD, Sun B. High IFN-alpha expression is associated with the induction of experimental autoimmune uveitis (EAU) in Fischer 344 rat. Cell Res 2001; 11:293-300. [PMID: 11794322 DOI: 10.1038/sj.cr.7290099] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Th1-response plays a crucial role in determining pathogenesis of organ-specific autoimmune diseases. It is believed that both IL-12 and INF-alpha are initiators to regulate Th1-response. In our experimental autoimmune uveitis (EAU) model, both Lewis and Fischer 344 rats share the same MHC class II molecules, while Lewis rat is EAU susceptible and Fischer 344 rat is EAU resistant. However, under the same condition of immunization, if pertussis toxin (PTX) was injected intraperitoneally as an additional adjuvant, Fischer 344 rat can develop EAU. In this study we investigate which mechanisms are involved in the induction of EAU in CFA+R16+PTX-treated (CRP-treated) Fischer 344 rats. In vivo and in vitro data demonstrated that Th1-cytokine, IFN-gamma mRNA expression was significantly increased in disease target tissue-eyes and in draining lymph node cells of CRP-treated Fischer 344 rat. When IL-12 and IFN-alpha mRNA expression were compared in the experimental groups, only IFN-alpha mRNA expression was associated with EAU development. To distinguish the sources of IFN-alpha producing cells, it was observed that IFN-alpha expression was mainly produced by macrophages. It was further confirmed that normal macrophage from Fischer 344 rat was able to produce significant IFN-alpha in the presence of PTX. The data strongly suggested that IFN-alpha might be involved in initiating Th1-cell differentiation and in turn contribute to the induction of EAU. High IFN-alpha expression induced by PTX may represent a novel pathway to initiate Th1 response in Fischer 344 rat.
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Rasko JE, Klenova EM, Leon J, Filippova GN, Loukinov DI, Vatolin S, Robinson AF, Hu YJ, Ulmer J, Ward MD, Pugacheva EM, Neiman PE, Morse HC, Collins SJ, Lobanenkov VV. Cell growth inhibition by the multifunctional multivalent zinc-finger factor CTCF. Cancer Res 2001; 61:6002-7. [PMID: 11507042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
The 11-zinc finger protein CCTC-binding factor (CTCF) employs different sets of zinc fingers to form distinct complexes with varying CTCF- target sequences (CTSs) that mediate the repression or activation of gene expression and the creation of hormone-responsive gene silencers and of diverse vertebrate enhancer-blocking elements (chromatin insulators). To determine how these varying effects would integrate in vivo, we engineered a variety of expression systems to study effects of CTCF on cell growth. Here we show that ectopic expression of CTCF in many cell types inhibits cell clonogenicity by causing profound growth retardation without apoptosis. In asynchronous cultures, the cell-cycle profile of CTCF-expressing cells remained unaltered, which suggested that progression through the cycle was slowed at multiple points. Although conditionally induced CTCF caused the S-phase block, CTCF can also arrest cell division. Viable CTCF-expressing cells could be maintained without dividing for several days. While MYC is the well-characterized CTCF target, the inhibitory effects of CTCF on cell growth could not be ascribed solely to repression of MYC, suggesting that additional CTS-driven genes involved in growth-regulatory circuits, such as p19ARF, are likely to contribute to CTCF-induced growth arrest. These findings indicate that CTCF may regulate cell-cycle progression at multiple steps within the cycle, and add to the growing evidence for the function of CTCF as a tumor suppressor gene.
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