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Pueraria lobata-derived exosome-like nanovesicles alleviate osteoporosis by enhacning autophagy. J Control Release 2023; 364:644-653. [PMID: 37967723 DOI: 10.1016/j.jconrel.2023.11.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 11/08/2023] [Accepted: 11/10/2023] [Indexed: 11/17/2023]
Abstract
Osteoporosis (OP) is the most common bone disorder worldwide, especially in postmenopausal women. However, many OP drugs are not suitable for long term use due to major adverse effects. Therefore, there is an urgent need to identify more effective and safe therapeutic drugs. Pueraria lobata has been reported to promote osteoblast growth in bone regeneration, but the exact mechanisms still need further exploration. The current study found that Pueraria lobata-derived exosome-like nanovesicles (PELNs) promoting primary human bone mesenchymal stem cells (hBMSCs) differentiation and mineralization both in vitro and in ovariectomized (OVX)-induced osteoporotic rats. Interestingly, the relative abundance of harmful strains significantly decreased in the intestine of the osteoporosis SD rat model administrated PELNs via the regulation of trimethylamine-N-oxide (TMAO), a metabolite of gut microbiota. Moreover, RNA sequencing revealed that the osteogenic activity of PELNs is revealed to autophagy signaling. In vitro and in vivo experiments also showed that the treatment with PELNs promoted the differentiation and function of hBMSCs by elevating autophagy via the degradation of TMAO. Collectively, PELNs demonstrate promise as a therapeutic approach for OP, with TMAO emerging as a potential target of OP treatment.
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Toxoplasma gondii excretory/secretory proteins promotes osteogenic differentiation of bone marrow mesenchymal stem cells via aerobic glycolysis mediated by Wnt/β‑catenin signaling pathway. Int J Mol Med 2023; 52:91. [PMID: 37594122 PMCID: PMC10483926 DOI: 10.3892/ijmm.2023.5294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 07/25/2023] [Indexed: 08/19/2023] Open
Abstract
Toxoplasma gondii excretory/secretory proteins (TgESPs) are a group of proteins secreted by the parasite and have an important role in the interaction between the host and Toxoplasma gondii (T. gondii). They can participate in various biological processes in different cells and regulate cellular energy metabolism. However, the effect of TgESPs on energy metabolism and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) has remained elusive. In the present study, TgESPs were extracted from the T. gondii RH strain and used to treat BMSCs to observe the effect of TgESPs on energy metabolism and osteogenic differentiation of BMSCs and to explore the molecular mechanisms involved. The osteogenic differentiation and energy metabolism of BMSCs were evaluated using Alizarin Red S staining, qRT-PCR, western blot, immunofluorescence and Seahorse extracellular flux assays. The results indicated that TgESPs activated the Wnt/β‑catenin signaling pathway to enhance glycolysis and lactate production in BMSCs, and promoted cell mineralization and expression of osteogenic markers. In conclusion, the present study uncovered the potential mechanism by which TgESPs regulate BMSCs, which will provide a theoretical reference for the study of the function of TgESPs in the future.
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Exosome-like Nanovesicles Derived from the Mucilage of Pinctada Martensii Exhibit Antitumor Activity against 143B Osteosarcoma Cells. ACS APPLIED MATERIALS & INTERFACES 2023. [PMID: 37226779 DOI: 10.1021/acsami.2c21485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Osteosarcoma is prone to metastasis and has a low long-term survival rate. The drug treatment of osteosarcoma, side effects of treatment drugs, and prognosis of patients with lung metastasis continue to present significant challenges, and the efficacy of drugs used in the treatment of osteosarcoma remains low. The development of new therapeutic drugs is urgently needed. In this study, we successfully isolated Pinctada martensii mucilage exosome-like nanovesicles (PMMENs). Our findings demonstrated that PMMENs inhibited the viability and proliferation of 143B cells, induced apoptosis, and inhibited cell proliferation by suppressing the activation of the ERK1/2 and Wnt signaling pathways. Furthermore, PMMENs inhibited cell migration and invasion by downregulating N-cadherin, vimentin, and matrix metalloprotease-2 protein expression levels. Transcriptomic and metabolomic analyses revealed that differential genes were co-enriched with differential metabolites in cancer signaling pathways. These results suggest that PMMENs may exert anti-tumor activity by targeting the ERK1/2 and Wnt signaling pathways. Moreover, tumor xenograft model experiments showed that PMMENs can inhibit the growth of osteosarcoma in mice. Thus, PMMENs may be a potential anti-osteosarcoma drug.
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DPA promotes hBMSCs osteogenic differentiation by miR-9-5p/ERK/ALP signaling pathway. Int J Med Sci 2022; 19:1879-1887. [PMID: 36438924 PMCID: PMC9682506 DOI: 10.7150/ijms.77729] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 10/10/2022] [Indexed: 01/25/2023] Open
Abstract
Docosahexaenoic acid (DHA) has been reported potentiate osteogenic differentiation, while Docosapentaenoic acid (DPA), another Omega-3 fatty acid, its contribution to the osteogenic differentiation of human bone-marrow-derived mesenchymal stromal cells (hBMSCs) is not entirely elucidated. The Alizarin Red S (ARS) staining and the expression of osteogenesis‑associated genes were analyzed during osteogenic induction by DPA. Then, bioinformatics analysis and dual luciferase reporter assays were investigated to confirm the interactions between miR-9-5p and alkaline phosphatase (ALP). miR-9-5p mimics / inhibitor were transfected to human hBMSCs and the osteogenic assay above was also performed. Furthermore, DPA significantly promoted the phosphorylation of ERK via miR-9-5p. PD98059, a highly specific and potent ERK1/2 inhibitor, inhibited the activation of ALP and partially reversed the role of DPA during osteogenic differentiation. These data indicated that DPA promoted osteogenic differentiation of hBMSCs potentially through miR-9-5p/ERK/ALP signaling pathway, providing a potentially useful therapeutic strategy for patients to improve bone loss.
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Toxoplasma gondii Induces Apoptosis via Endoplasmic Reticulum Stress-Derived Mitochondrial Pathway in Human Small Intestinal Epithelial Cell-Line. THE KOREAN JOURNAL OF PARASITOLOGY 2021; 59:573-583. [PMID: 34974664 PMCID: PMC8721304 DOI: 10.3347/kjp.2021.59.6.573] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 11/18/2021] [Indexed: 01/16/2023]
Abstract
Toxoplasma gondii, an intracellular protozoan parasite that infects one-third of the world’s population, has been reported to hijack host cell apoptotic machinery and promote either an anti- or proapoptotic program depending on the parasite virulence and load and the host cell type. However, little is known about the regulation of human FHs 74 small intestinal epithelial cell viability in response to T. gondii infection. Here we show that T. gondii RH strain tachyzoite infection or ESP treatment of FHs 74 Int cells induced apoptosis, mitochondrial dysfunction and ER stress in host cells. Pretreatment with 4-PBA inhibited the expression or activation of key molecules involved in ER stress. In addition, both T. gondii and ESP challenge-induced mitochondrial dysfunction and cell death were dramatically suppressed in 4-PBA pretreated cells. Our study indicates that T. gondii infection induced ER stress in FHs 74 Int cells, which induced mitochondrial dysfunction followed by apoptosis. This may constitute a potential molecular mechanism responsible for the foodborne parasitic disease caused by T. gondii.
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Abstract P3-03-08: Not presented. Cancer Res 2019. [DOI: 10.1158/1538-7445.sabcs18-p3-03-08] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
This abstract was not presented at the conference.
Citation Format: Liang Y, Chen X, Zhan W, Zhu Y, Wu J, Huang O, He J, Zhu L, Li Y, Chen W, Shen K. Not presented [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-03-08.
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Reply to Comment on 'Nanoscale mapping of optical band gaps using monochromated electron energy loss spectroscopy'. NANOTECHNOLOGY 2018; 29:318002. [PMID: 29749345 DOI: 10.1088/1361-6528/aac3ed] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We respond to the comment by Thomas Walther and reaffirm the findings of our original article.
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Recombinant phosphoglucomutase and CAMP factor as potential subunit vaccine antigens induced high protection against Streptococcus iniae infection in flounder (Paralichthys olivaceus). J Appl Microbiol 2018; 125:997-1007. [PMID: 29877008 DOI: 10.1111/jam.13948] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 04/17/2018] [Accepted: 06/01/2018] [Indexed: 12/14/2022]
Abstract
AIMS The aim of this study was to screen vaccine candidates from virulence factors of Streptococcus iniae in flounder model. METHODS AND RESULTS The immunogenicity of recombinant phosphoglucomutase (rPGM) and rCAMP factor was confirmed by Western blot. The percentage of surface membrane immunoglobulin-positive (sIg+ ) lymphocytes in peripheral blood leucocytes, the specific and total serum IgM and the activity of acid phosphatase (ACP) and peroxidase (POD) in flounder were determined with flow cytometry, ELISA and commercial enzyme activity kits, respectively, after intraperitoneal immunization with rPGM and rCAMP factor. The results showed that rPGM and rCAMP factor could induce significant rise in sIg+ lymphocytes, specific serum IgM and activities of ACP and POD. Additionally, the relative percent survival rate of the vaccinated flounder was 64 and 54% in challenge experiment using S. iniae, respectively. These results indicated that rPGM and rCAMP factor could evoke humoural and innate immune response in flounder and provide high-efficiency immunoprotection against S. iniae infection. CONCLUSIONS Phosphoglucomutase (PGM) and CAMP factor were promising vaccine candidates against S. iniae in flounder. SIGNIFICANCE AND IMPACT OF THE STUDY Phosphoglucomutase and CAMP factor have the potential to be vaccine candidates, which provide important information for us to develop the effective subunit vaccines, especially the multivaccine, against S .iniae in aquaculture.
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Nanoscale mapping of optical band gaps using monochromated electron energy loss spectroscopy. NANOTECHNOLOGY 2017; 28:105703. [PMID: 28085004 DOI: 10.1088/1361-6528/aa5962] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Using monochromated electron energy loss spectroscopy in a probe-corrected scanning transmission electron microscope we demonstrate band gap mapping in ZnO/ZnCdO thin films with a spatial resolution below 10 nm and spectral precision of 20 meV.
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Study on the effects of blueberry treatment on histone acetylation modification of CCl 4-induced liver disease in rats. GENETICS AND MOLECULAR RESEARCH 2017; 16:gmr-16-01-gmr.16019188. [DOI: 10.4238/gmr16019188] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Percutaneous laser ablation for treatment of locally recurrent papillary thyroid carcinoma <15 mm. Clin Radiol 2016; 71:1233-1239. [PMID: 27554615 DOI: 10.1016/j.crad.2016.07.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 07/06/2016] [Accepted: 07/13/2016] [Indexed: 01/06/2023]
Abstract
AIM To evaluate the efficacy and safety of ultrasound-guided percutaneous laser ablation (PLA) for recurrent papillary thyroid carcinomas (PTC) <15 mm in the neck. MATERIALS AND METHODS A retrospective study was conducted in 21 patients with 27 recurrent PTC lesions who underwent PLA. The extent of ablation was assessed by contrast-enhanced ultrasonography (CEUS) after PLA. Measurement of the volume of tumour and serum thyroglobulin, and clinical evaluation were performed at 7 days, and 1, 3, 6, and 12 months, and every 6 months thereafter. RESULTS The procedure was well tolerated. Of 21 patients, 18 were successfully treated in a single session. Incomplete ablation was detected by CEUS in three patients, and a second ablation was performed. The mean largest diameter and the average baseline volume were reduced from 7.5±2.8 mm and 105.4±114 mm3 to 0.4±1 mm and 0.8±2.4 mm3 at the final follow-up. CONCLUSIONS Ultrasound-guided PLA is effective for the treatment of recurrent PTCs with a comparable success rate to radio-iodine therapy, and it may become a primary choice of treatment for recurrent PTCs in selected patients who are ineligible for surgery and/or prefer not to have further surgery.
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Overexpression of ZWF1 and POS5 improves carotenoid biosynthesis in recombinant Saccharomyces cerevisiae. Lett Appl Microbiol 2015; 61:354-60. [PMID: 26179622 DOI: 10.1111/lam.12463] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 06/15/2015] [Accepted: 06/24/2015] [Indexed: 11/28/2022]
Abstract
UNLABELLED Recombinant Saccharomyces cerevisiae expressing exogenous carotenogenic genes can synthesize carotenoids. NADPH is a key cofactor for carotenoid biosynthesis, while glucose-6-phosphate dehydrogenase (Zwf1) and an NADH kinase (Pos5) are the two main NADPH-supplying sources in S. cerevisiae. Here, the effect of ZWF1 and POS5 overexpression on carotenoid yield in recombinant S. cerevisiae was explored. The initial carotenogenic strain Sc-EYBIH+I which expressed crtE, crtYB, crtI, cHMG1 and another copy of crtI could synthesize 1·35 ± 0·13 mg l(-1) of lycopene and 0·32 ± 0·02 mg l(-1) of β-carotene. When ZWF1 was overexpressed (Sc-EYBIZH+I), glucose-6-phosphate dehydrogenase activity increased by 103-fold, the transcription level of crtE and crtI increased significantly, the lycopene and β-carotene yield increased to 2·29 ± 0·06 and 0·38 ± 0·02 mg l(-1) respectively. When POS5 was overexpressed (Sc-EYBIPH+I), NAD kinase activity increased by 5·5-fold, the transcription level of crtE, crtYB and crtI increased obviously, the lycopene and β-carotene yield increased to 2·50 ± 0·11 and 0·53 ± 0·03 mg l(-1) respectively. Therefore, improvement of NADPH supply contributed to carotenoids biosynthesis in S. cerevisiae and overexpression of POS5 was more effective than overexpression of ZWF1. This study provides a new strategy for enhancing carotenoid biosynthesis. SIGNIFICANCE AND IMPACT OF THE STUDY NADPH is a key cofactor for carotenoid biosynthesis. Glucose-6-phosphate dehydrogenase (Zwf1) and an NADH kinase (Pos5) are effective NADPH-supplying sources in Saccharomyces cerevisiae. When ZWF1 and POS5 were overexpressed in a carotenoid-producing S. cerevisiae strain individually, the total yield of lycopene and β-carotene increased by 59·9% and 81·4%, respectively, and the final product β-carotene yield increased by 18·8% and 65·6% respectively. This suggests the improvement of NADPH supply as a useful strategy for carotenoids biosynthesis.
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The delayed massive hemorrhage after gastrectomy in patients with gastric cancer: characteristics, management opinions and risk factors. Eur J Surg Oncol 2014; 40:1299-306. [PMID: 24731269 DOI: 10.1016/j.ejso.2014.03.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Revised: 12/02/2013] [Accepted: 03/22/2014] [Indexed: 01/28/2023] Open
Abstract
AIMS This study was designed to investigate the clinical features of delayed massive hemorrhage (DMH) after gastrectomy in patients with gastric cancer (GC). METHODS This study retrospectively reviewed 1536 GC patients with major gastrectomy between 1998 and 2011. Based on the time onset of postoperative bleeding, patients were divided into early postoperative hemorrhage (EPH), delayed massive hemorrhage (DMH), and no-bleeding groups. Postoperative mortality, bleeding treatment, and risk factors of hemorrhage were explored. RESULTS In sum, 15 (0.9%) patients suffered from DMH, with three (20%) dead cases. None of 18 (1.2%) patients with EPH died, but there were three dead cases in no-bleeding group. DMH had more extra-intestinal bleeding (P = 0.037) than EPH. Angiographic embolization was performed in 12 (80%) of DMH patients and successful in ten cases. Surgical procedures were applied in only two embolization-failed cases. Extended lymphadenectomy (P = 0.038), vascular skeletonization (P = 0.012) and advanced TNM stage (P < 0.001) were correlated with DMH. CONCLUSIONS DMH can be successfully managed with angiographic embolization, followed by alternative surgery. Extensive lymphadenectomy and vascular skeletonization should be discreetly performed during gastrectomy.
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Adolescents and young adults with newly diagnosed Type 2 diabetes demonstrate greater carotid intima-media thickness than those with Type 1 diabetes. Diabet Med 2014; 31:84-91. [PMID: 24112039 DOI: 10.1111/dme.12335] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 08/31/2013] [Accepted: 09/19/2013] [Indexed: 12/14/2022]
Abstract
AIM To compare the carotid intima-media thickness in patients with newly diagnosed Type 1 or Type 2 diabetes ranging from 14 to 30 years of age. METHODS Demographic, anthropometric and laboratory data were obtained from 404 adolescents and young adults (103 subjects with Type 1 diabetes, 94 with Type 2 diabetes, 153 obese subjects and 54 normal control subjects). Carotid intima-media thickness was assessed based on Doppler ultrasound examination and compared among the four groups. RESULTS Our data showed significant increases in carotid intima-media thickness in subjects with Type 1 diabetes, Type 2 diabetes and obese subjects compared with the control subjects, with those in the group with Type 2 diabetes demonstrating the greatest change (P < 0.001). Age, BMI, percentage of fat, waist-hip ratio and total triglycerides were significantly correlated with both common and internal carotid intima-media thickness segments. From a stepwise multiple linear regression model, the independent determinants of common carotid intima-media thickness were age, BMI, HbA1c and HDL cholesterol (adjusted R(2) = 0.152, P < 0.001). After adjustment for age, sex and HbA1c , the odds ratio for increased carotid intima-media thickness was 1.67 (95% CI 1.19-2.33, P = 0.003) for obese subjects, 2.38 (95% CI 1.59-9.47, P = 0.001) for subjects with Type 1 diabetes and 3.93 (95% CI 1.90-6.07, P = 0001) for subjects with Type 2 diabetes compared with the control subjects. CONCLUSIONS Compared with young control subjects, we found significant increases in carotid intima-media thickness in patients with newly diagnosed Type 1 diabetes and Type 2 diabetes, with patients with Type 2 diabetes showing greater carotid intima-media thickness. Traditional cardiovascular risk factors, such as obesity, dyslipidaemia, hypertension and hyperglycaemia, could cause vessel changes even in adolescents and young adults.
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Development and characterization of novel microsatellite markers in the rock bream fish Oplegnathus fasciatus. GENETICS AND MOLECULAR RESEARCH 2013; 12:6462-5. [PMID: 24390995 DOI: 10.4238/2013.december.10.7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The rock bream fish Oplegnathus fasciatus is one of the most popular aquaculture species in China. In the present study, 15 novel polymorphic microsatellite loci were isolated and characterized from a wild population of O. fasciatus from the Zhoushan coast of China. The number of alleles per polymorphic locus ranged from 4 to 9 in a sample of 30 individuals. Observed and expected heterozygosities per locus varied from 0.267 to 0.767 and from 0.395 to 0.859, respectively. Eleven of the 15 microsatellite loci conformed to Hardy-Weinberg equilibrium. No significant linkage disequilibrium between pairs of loci was detected. The present microsatellite markers could provide a useful tool for the genetic analyses of O. fasciatus.
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Isolation and characterization of novel microsatellite loci in Nibea albiflora. GENETICS AND MOLECULAR RESEARCH 2013; 12:6156-9. [PMID: 24338409 DOI: 10.4238/2013.december.4.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Eleven novel microsatellite loci were isolated from a (CA)10-enriched genomic DNA library of Nibea albiflora. The characteristics of these microsatellites were determined in a sample of 48 N. albiflora individuals. The number of alleles at the 11 microsatellite loci ranged from 5 to 25, with an average of 13.5 per locus. The observed and expected heterozygosities varied from 0.583 to 0.917 and from 0.568 to 0.964, respectively. Eight of the 11 microsatellite loci conformed to the Hardy-Weinberg equilibrium. No significant linkage disequilibrium was found among all 11 loci. These polymorphic microsatellites will be useful for population genetic analyses of N. albiflora.
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Gaseous and Particle-bound VOC Products of Combustion Extracted by Needle Trap Samplers. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.201200654] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Regulatory B cells are induced in untreated HIV-1 infection and suppress HIV-1 specific T cell responses. Retrovirology 2012. [PMCID: PMC3441886 DOI: 10.1186/1742-4690-9-s2-p102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Abstract
Background Metastasis, the spread and growth of tumor cells to distant organ sites, represents the most devastating attribute and plays a major role in the morbidity and mortality of cancer. Inflammation is crucial for malignant tumor transformation and survival. Thus, blocking inflammation is expected to serve as an effective cancer treatment. Among anti-inflammation therapies, chemokine modulation is now beginning to emerge from the pipeline. CXC chemokine receptor-4 (CXCR4) and its ligand stromal cell-derived factor-1 (CXCL12) interaction and the resulting cell signaling cascade have emerged as highly relevant targets since they play pleiotropic roles in metastatic progression. The unique function of CXCR4 is to promote the homing of tumor cells to their microenvironment at the distant organ sites. Methodology/Principal Findings We describe the actions of N,N′-(1,4-phenylenebis(methylene))dipyrimidin-2-amine (designated MSX-122), a novel small molecule and partial CXCR4 antagonist with properties quite unlike that of any other reported CXCR4 antagonists, which was prepared in a single chemical step using a reductive amination reaction. Its specificity toward CXCR4 was tested in a binding affinity assay and a ligand competition assay using 18F-labeled MSX-122. The potency of the compound was determined in two functional assays, Matrigel invasion assay and cAMP modulation. The therapeutic potential of MSX-122 was evaluated in three different murine models for inflammation including an experimental colitis, carrageenan induced paw edema, and bleomycin induced lung fibrosis and three different animal models for metastasis including breast cancer micrometastasis in lung, head and neck cancer metastasis in lung, and uveal melanoma micrometastasis in liver in which CXCR4 was reported to play crucial roles. Conclusions/Significance We developed a novel small molecule, MSX-122, that is a partial CXCR4 antagonist without mobilizing stem cells, which can be safer for long-term blockade of metastasis than other reported CXCR4 antagonists.
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White matter alterations in cognitively normal apoE ε2 carriers: insight into Alzheimer resistance? AJNR Am J Neuroradiol 2012; 33:1392-7. [PMID: 22383234 DOI: 10.3174/ajnr.a2984] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The basis for decreased vulnerability to AD among apoE ε2 carriers is unknown. The purpose of this study was to use diffusion tensor imaging to detect possible differences in white matter integrity between cognitively normal elderly apoE ε2 carriers and apoE ε3/ε3 controls. MATERIALS AND METHODS Thirty-nine cognitively normal elderly individuals (19 heterozygous carriers of the apoE ε2 allele, 20 apoE ε3/ε3 subjects as controls) underwent diffusion tensor MR imaging on a 4T scanner. Fractional anisotropy, MD, and axial and radial diffusivity were compared using a ROI approach. In addition, an exploratory whole-brain analysis of fractional anisotropy between the 2 groups was undertaken using TBSS. RESULTS apoE ε2 carriers had higher FA in the posterior cingulate white matter (P = .01) and anterior corpus callosum (P = .005) than apoE ε3/ε3 controls, secondary to lower radial diffusivity. No significant differences in the FA of the posterior corpus callosum, anterior cingulate white matter, or parahippocampal white matter were seen. Whole-brain TBSS analysis detected regions of higher FA in the apoE ε2 group in the superior longitudinal fasciculus, right thalamus, and the bilateral anterior limbs of the internal capsule, in addition to the posterior cingulum and corpus callosum (P < .005). There were no regions in which the apoE ε3/ε3 group had higher FA. CONCLUSIONS apoE ε2 carriers harbor more robust white matter integrity that may be associated with decreased vulnerability to developing AD. This provides further evidence that regional DTI metrics may serve as early imaging biomarkers of AD risk.
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Identified hadron compositions in p+p and Au+Au collisions at high transverse momenta at √S(NN)=200 GeV. PHYSICAL REVIEW LETTERS 2012; 108:072302. [PMID: 22401197 DOI: 10.1103/physrevlett.108.072302] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Indexed: 05/31/2023]
Abstract
We report transverse momentum (p(T)≤15 GeV/c) spectra of π(±), K(±), p, p[over ¯], K(S)(0), and ρ(0) at midrapidity in p+p and Au+Au collisions at √S(NN)=200 GeV. Perturbative QCD calculations are consistent with π(±) spectra in p+p collisions but do not reproduce K and p(p[over ¯]) spectra. The observed decreasing antiparticle-to-particle ratios with increasing p(T) provide experimental evidence for varying quark and gluon jet contributions to high-p(T) hadron yields. The relative hadron abundances in Au+Au at p(T)≳8 GeV/c are measured to be similar to the p+p results, despite the expected Casimir effect for parton energy loss.
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Strangeness enhancement in Cu-Cu and Au-Au collisions at √S(NN)=200 GeV. PHYSICAL REVIEW LETTERS 2012; 108:072301. [PMID: 22401196 DOI: 10.1103/physrevlett.108.072301] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Indexed: 05/31/2023]
Abstract
We report new STAR measurements of midrapidity yields for the Λ, Λ[over ¯], K(S)(0), Ξ(-), Ξ[over ¯](+), Ω(-), Ω[over ¯](+) particles in Cu+Cu collisions at √S(NN)==200 GeV, and midrapidity yields for the Λ, Λ[over ¯], K(S)(0) particles in Au+Au at √S(NN)==200 GeV. We show that, at a given number of participating nucleons, the production of strange hadrons is higher in Cu+Cu collisions than in Au+Au collisions at the same center-of-mass energy. We find that aspects of the enhancement factors for all particles can be described by a parametrization based on the fraction of participants that undergo multiple collisions.
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Preclinical Model to Predict Anti-Leukemic Activity of Busulfan and Irradiation. Biol Blood Marrow Transplant 2012. [DOI: 10.1016/j.bbmt.2011.12.509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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C6-C8 bridged epothilones: consequences of installing a conformational lock at the edge of the macrocycle. Chemistry 2011; 17:14792-804. [PMID: 22127984 PMCID: PMC3248799 DOI: 10.1002/chem.201102630] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Indexed: 11/08/2022]
Abstract
A series of conformationally restrained epothilone analogues with a short bridge between the methyl groups at C6 and C8 was designed to mimic the binding pose assigned to our recently reported EpoA-microtubule binding model. A versatile synthetic route to these bridged epothilone analogues has been successfully devised and implemented. Biological evaluation of the compounds against A2780 human ovarian cancer and PC3 prostate cancer cell lines suggested that the introduction of a bridge between C6-C8 reduced potency by 25-1000 fold in comparison with natural epothilone D. Tubulin assembly measurements indicate these bridged epothilone analogues to be mildly active, but without significant microtubule stabilization capacity. Molecular mechanics and DFT energy evaluations suggest the mild activity of the bridged epo-analogues may be due to internal conformational strain.
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25
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Abstract
The total synthesis of hirsutellones A (1), B (2), and C (3) has been achieved through a bioinspired late-stage sequence starting from advanced intermediate 6. The sequence proceeded via labile intermediate 17,1'-dehydrohirsutellone B (5) and delivered, in addition to the natural products (1-3), hirsutellone analogue 1',2',17-epi-hirsutellone C (1',2',17-epi-3).
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26
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27
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Measurement of the parity-violating longitudinal single-spin asymmetry for W± boson production in polarized proton-proton collisions at sqrt[s] = 500 GeV. PHYSICAL REVIEW LETTERS 2011; 106:062002. [PMID: 21405460 DOI: 10.1103/physrevlett.106.062002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Indexed: 05/30/2023]
Abstract
We report the first measurement of the parity-violating single-spin asymmetries for midrapidity decay positrons and electrons from W+ and W- boson production in longitudinally polarized proton-proton collisions at sqrt[s] = 500 GeV by the STAR experiment at RHIC. The measured asymmetries, A(L)(W+) = -0.27 ± 0.10(stat.) ± 0.02(syst.) ± 0.03(norm.) and A(L)(W-) = 0.14 ± 0.19(stat.) ± 0.02(syst.) ± 0.01(norm.), are consistent with theory predictions, which are large and of opposite sign. These predictions are based on polarized quark and antiquark distribution functions constrained by polarized deep-inelastic scattering measurements.
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28
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Dipyrimidine amines: a novel class of chemokine receptor type 4 antagonists with high specificity. J Med Chem 2010; 53:8556-68. [PMID: 21105715 DOI: 10.1021/jm100786g] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The C-X-C chemokine receptor type 4 (CXCR4)/stromal cell derived factor-1 (SDF-1 or CXCL12) interaction and the resulting cell signaling cascade play a key role in metastasis and inflammation. On the basis of the previously published CXCR4 antagonist 5 (WZ811), a series of novel nonpeptidic anti-CXCR4 small molecules have been designed and synthesized to improve potency. Following a structure-activity profile around 5, more advanced compounds in the N,N'-(1, 4-phenylenebis(methylene)) dipyrimidin-2-amines series were discovered and shown to possess higher CXCR4 binding potential and specificity than 5. Compound 26 (508MCl) is the lead compound and exhibits subnanomolar potency in three in vitro assays including competitive binding, Matrigel invasion and Gα(i) cyclic adenosine monophosphate (cAMP) modulation signaling. Furthermore, compound 26 displays promising effects by interfering with CXCR4 function in three mouse models: paw inflammation, Matrigel plug angiogenesis, and uveal melanoma micrometastasis. These data demonstrate that dipyrimidine amines are unique CXCR4 antagonists with high potency and specificity.
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29
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Measurement of the bottom quark contribution to nonphotonic electron production in p + p collisions at √s=200 GeV. PHYSICAL REVIEW LETTERS 2010; 105:202301. [PMID: 21231222 DOI: 10.1103/physrevlett.105.202301] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Indexed: 05/30/2023]
Abstract
The contribution of B meson decays to nonphotonic electrons, which are mainly produced by the semileptonic decays of heavy-flavor mesons, in p + p collisions at √s=200 GeV has been measured using azimuthal correlations between nonphotonic electrons and hadrons. The extracted B decay contribution is approximately 50% at a transverse momentum of pT≥5 GeV/c. These measurements constrain the nuclear modification factor for electrons from B and D meson decays. The result indicates that B meson production in heavy ion collisions is also suppressed at high pT.
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30
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Higher moments of net proton multiplicity distributions at RHIC. PHYSICAL REVIEW LETTERS 2010; 105:022302. [PMID: 20867702 DOI: 10.1103/physrevlett.105.022302] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Indexed: 05/29/2023]
Abstract
We report the first measurements of the kurtosis (κ), skewness (S), and variance (σ2) of net-proton multiplicity (Np-Np) distributions at midrapidity for Au+Au collisions at square root of s(NN)=19.6, 62.4, and 200 GeV corresponding to baryon chemical potentials (μB) between 200 and 20 MeV. Our measurements of the products κσ2 and Sσ, which can be related to theoretical calculations sensitive to baryon number susceptibilities and long-range correlations, are constant as functions of collision centrality. We compare these products with results from lattice QCD and various models without a critical point and study the square root of s(NN) dependence of κσ2. From the measurements at the three beam energies, we find no evidence for a critical point in the QCD phase diagram for μB below 200 MeV.
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31
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Three-particle coincidence of the long range pseudorapidity correlation in high energy nucleus-nucleus collisions. PHYSICAL REVIEW LETTERS 2010; 105:022301. [PMID: 20867701 DOI: 10.1103/physrevlett.105.022301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Indexed: 05/29/2023]
Abstract
We report the first three-particle coincidence measurement in pseudorapidity (Δη) between a high transverse momentum (p⊥) trigger particle and two lower p⊥ associated particles within azimuth |Δϕ|<0.7 in square root of s(NN)=200 GeV d+Au and Au+Au collisions. Charge ordering properties are exploited to separate the jetlike component and the ridge (long range Δη correlation). The results indicate that the correlation of ridge particles are uniform not only with respect to the trigger particle but also between themselves event by event in our measured Δη. In addition, the production of the ridge appears to be uncorrelated to the presence of the narrow jetlike component.
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32
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33
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Azimuthal charged-particle correlations and possible local strong parity violation. PHYSICAL REVIEW LETTERS 2009; 103:251601. [PMID: 20366248 DOI: 10.1103/physrevlett.103.251601] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Indexed: 05/29/2023]
Abstract
Parity-odd domains, corresponding to nontrivial topological solutions of the QCD vacuum, might be created during relativistic heavy-ion collisions. These domains are predicted to lead to charge separation of quarks along the system's orbital momentum axis. We investigate a three-particle azimuthal correlator which is a P even observable, but directly sensitive to the charge separation effect. We report measurements of charged hadrons near center-of-mass rapidity with this observable in Au + Au and Cu + Cu collisions at square root of s(NN) = 200 GeV using the STAR detector. A signal consistent with several expectations from the theory is detected. We discuss possible contributions from other effects that are not related to parity violation.
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34
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35
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Growth of long range forward-backward multiplicity correlations with centrality in Au + Au collisions at square root of sNN = 200 GeV. PHYSICAL REVIEW LETTERS 2009; 103:172301. [PMID: 19905749 DOI: 10.1103/physrevlett.103.172301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2009] [Indexed: 05/28/2023]
Abstract
Forward-backward multiplicity correlation strengths have been measured with the STAR detector for Au + Au and p + p collisions at square root of s(NN) = 200 GeV. Strong short- and long-range correlations (LRC) are seen in central Au + Au collisions. The magnitude of these correlations decrease with decreasing centrality until only short-range correlations are observed in peripheral Au + Au collisions. Both the dual parton model (DPM) and the color glass condensate (CGC) predict the existence of the long-range correlations. In the DPM, the fluctuation in the number of elementary (parton) inelastic collisions produces the LRC. In the CGC, longitudinal color flux tubes generate the LRC. The data are in qualitative agreement with the predictions of the DPM and indicate the presence of multiple parton interactions.
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36
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37
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K/pi Fluctuations at relativistic energies. PHYSICAL REVIEW LETTERS 2009; 103:092301. [PMID: 19792791 DOI: 10.1103/physrevlett.103.092301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Indexed: 05/28/2023]
Abstract
We report K/pi fluctuations from Au + Au collisions at sqrt[s(NN)]= 19.6, 62.4, 130, and 200 GeV using the STAR detector at the Relativistic Heavy Ion Collider. K/pi fluctuations in central collisions show little dependence on incident energy and are on the same order as those from NA49 at the Super Proton Synchrotron in central Pb + Pb collisions at sqrt[s(NN)]=12.3 and 17.3 GeV. We report results for the collision centrality dependence of K/pi fluctuations and results for charge-separated fluctuations. We observe that the K/pi fluctuations scale with the charged particle multiplicity density.
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38
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39
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Abstract: P1353 BIRTH YEAR AND THE PREVALENCE OF CARDIOVASCULAR DISEASE. ATHEROSCLEROSIS SUPP 2009. [DOI: 10.1016/s1567-5688(09)70321-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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40
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Observation of two-source interference in the photoproduction reaction AuAu --> AuAurho0. PHYSICAL REVIEW LETTERS 2009; 102:112301. [PMID: 19392193 DOI: 10.1103/physrevlett.102.112301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Indexed: 05/27/2023]
Abstract
In ultraperipheral relativistic heavy-ion collisions, a photon from the electromagnetic field of one nucleus can fluctuate to a quark-antiquark pair and scatter from the other nucleus, emerging as a rho{0}. The rho{0} production occurs in two well-separated (median impact parameters of 20 and 40 F for the cases considered here) nuclei, so the system forms a two-source interferometer. At low transverse momenta, the two amplitudes interfere destructively, suppressing rho{0} production. Since the rho{0} decays before the production amplitudes from the two sources can overlap, the two-pion system can only be described with an entangled nonlocal wave function, and is thus an example of the Einstein-Podolsky-Rosen paradox. We observe this suppression in 200 GeV per nucleon-pair gold-gold collisions. The interference is 87%+/-5%(stat.)+/-8%(syst.) of the expected level. This translates into a limit on decoherence due to wave function collapse or other factors of 23% at the 90% confidence level.
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41
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Indications of conical emission of charged hadrons at the BNL relativistic heavy ion collider. PHYSICAL REVIEW LETTERS 2009; 102:052302. [PMID: 19257508 DOI: 10.1103/physrevlett.102.052302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Indexed: 05/27/2023]
Abstract
Three-particle azimuthal correlation measurements with a high transverse momentum trigger particle are reported for pp, d+Au, and Au+Au collisions at sqrt[s_{NN}]=200 GeV by the STAR experiment. Dijet structures are observed in pp, d+Au and peripheral Au+Au collisions. An additional structure is observed in central Au+Au data, signaling conical emission of correlated charged hadrons. The conical emission angle is found to be theta=1.37+/-0.02(stat)-0.07+0.06(syst), independent of p_{ perpendicular}.
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42
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System-size independence of directed flow measured at the BNL relativistic heavy-ion collider. PHYSICAL REVIEW LETTERS 2008; 101:252301. [PMID: 19113699 DOI: 10.1103/physrevlett.101.252301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2008] [Indexed: 05/27/2023]
Abstract
We measure directed flow (v_{1}) for charged particles in Au+Au and Cu+Cu collisions at sqrt[s_{NN}]=200 and 62.4 GeV, as a function of pseudorapidity (eta), transverse momentum (p_{t}), and collision centrality, based on data from the STAR experiment. We find that the directed flow depends on the incident energy but, contrary to all available model implementations, not on the size of the colliding system at a given centrality. We extend the validity of the limiting fragmentation concept to v_{1} in different collision systems, and investigate possible explanations for the observed sign change in v_{1}(p_{t}).
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43
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Forward neutral-pion transverse single-spin asymmetries in p + p collisions at sqrt[s] = 200 GeV. PHYSICAL REVIEW LETTERS 2008; 101:222001. [PMID: 19113478 DOI: 10.1103/physrevlett.101.222001] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2008] [Indexed: 05/27/2023]
Abstract
We report precision measurements of the Feynman x (xF) dependence, and first measurements of the transverse momentum (pT) dependence, of transverse single-spin asymmetries for the production of pi0 mesons from polarized proton collisions at sqrt[s] = 200 GeV. The xF dependence of the results is in fair agreement with perturbative QCD model calculations that identify orbital motion of quarks and gluons within the proton as the origin of the spin effects. Results for the pT dependence at fixed xF are not consistent with these same perturbative QCD-based calculations.
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44
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Longitudinal double-spin asymmetry for inclusive jet production in p[over -->] + p[over -->] collisions at sqrt[s]=200 GeV. PHYSICAL REVIEW LETTERS 2008; 100:232003. [PMID: 18643488 DOI: 10.1103/physrevlett.100.232003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2007] [Indexed: 05/26/2023]
Abstract
We report a new STAR measurement of the longitudinal double-spin asymmetry A(LL) for inclusive jet production at midrapidity in polarized p + p collisions at a center-of-mass energy of sqrt[s]=200 GeV. The data, which cover jet transverse momenta 5<p(T)<30 GeV/c, are substantially more precise than previous measurements. They provide significant new constraints on the gluon spin contribution to the nucleon spin through the comparison to predictions derived from one global fit to polarized deep-inelastic scattering measurements.
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45
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Abstract
A conformationally restrained epothilone A analogue (3) with a short bridge between methyl groups at C6 and C8 was designed and synthesized. Preliminary biological evaluation indicates 3 to be only weakly active (IC50 = 8.5 microM) against the A2780 human ovarian cancer cell line.
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46
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Abstract
In light of a proposed molecular mechanism for the C-X-C chemokine receptor type 4 (CXCR4) antagonist 1 (AMD3100), a template with the general structure 2 was designed, and 15 was identified as a lead by means of an affinity binding assay against the ligand-mimicking CXCR4 antagonist 3 (TN14003). Following a structure-activity profile around 15, the design and synthesis of a series of novel small molecular CXCR4 antagonists led to the discovery of 32 (WZ811). The compound shows subnanomolar potency (EC50 = 0.3 nM) in an affinity binding assay. In addition, when subjected to in vitro functional evaluation, 32 efficiently inhibits CXCR4/stromal cell-derived factor-1 (SDF-1)-mediated modulation of cyclic adenosine monophophate (cAMP) levels (EC50 = 1.2 nM) and SDF-1 induced Matrigel invasion (EC50 = 5.2 nM). Molecular field topology analysis (MFTA), a 2D quantitative structure-activity relationship (QSAR) approach based on local molecular properties (Van der Waals radii (VdW), atomic charges, and local lipophilicity), applied to the 32 series suggests structural modifications to improve potency.
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47
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Measurement of transverse single-spin asymmetries for Dijet production in proton-proton collisions at sqrt[s]=200 GeV. PHYSICAL REVIEW LETTERS 2007; 99:142003. [PMID: 17930662 DOI: 10.1103/physrevlett.99.142003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2007] [Indexed: 05/25/2023]
Abstract
We report the first measurement of the opening angle distribution between pairs of jets produced in high-energy collisions of transversely polarized protons. The measurement probes (Sivers) correlations between the transverse spin orientation of a proton and the transverse momentum directions of its partons. With both beams polarized, the wide pseudorapidity (-1< or = eta < or = +2) coverage for jets permits separation of Sivers functions for the valence and sea regions. The resulting asymmetries are all consistent with zero and considerably smaller than Sivers effects observed in semi-inclusive deep inelastic scattering. We discuss theoretical attempts to reconcile the new results with the sizable transverse spin effects seen in semi-inclusive deep inelastic scattering and forward hadron production in pp collisions.
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48
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Partonic Flow and phi-Meson production in Au+Au collisions at sqrt radical sNN = 200 GeV. PHYSICAL REVIEW LETTERS 2007; 99:112301. [PMID: 17930430 DOI: 10.1103/physrevlett.99.112301] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Indexed: 05/25/2023]
Abstract
We present first measurements of the phi-meson elliptic flow (v2(pT)) and high-statistics pT distributions for different centralities from radical sNN=200 GeV Au+Au collisions at RHIC. In minimum bias collisions the v2 of the phi meson is consistent with the trend observed for mesons. The ratio of the yields of the Omega to those of the phi as a function of transverse momentum is consistent with a model based on the recombination of thermal s quarks up to pT approximately 4 GeV/c, but disagrees at higher momenta. The nuclear modification factor (R CP) of phi follows the trend observed in the K S 0 mesons rather than in Lambda baryons, supporting baryon-meson scaling. These data are consistent with phi mesons in central Au+Au collisions being created via coalescence of thermalized s quarks and the formation of a hot and dense matter with partonic collectivity at RHIC.
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49
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Transverse momentum and centrality dependence of high-pT nonphotonic electron suppression in Au+Au collisions at sqrt[s NN]=200 GeV. PHYSICAL REVIEW LETTERS 2007; 98:192301. [PMID: 17677616 DOI: 10.1103/physrevlett.98.192301] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2006] [Revised: 01/15/2007] [Indexed: 05/16/2023]
Abstract
The STAR collaboration at the BNL Relativistic Heavy-Ion Collider (RHIC) reports measurements of the inclusive yield of nonphotonic electrons, which arise dominantly from semileptonic decays of heavy flavor mesons, over a broad range of transverse momenta (1.2<p(T)<10 GeV/c) in p+p, d+Au, and Au+Au collisions at sqrt[s_{NN}]=200 GeV. The nonphotonic electron yield exhibits an unexpectedly large suppression in central Au+Au collisions at high p(T), suggesting substantial heavy-quark energy loss at RHIC. The centrality and p(T) dependences of the suppression provide constraints on theoretical models of suppression.
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50
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Scaling properties of hyperon production in Au+Au collisions at square root [sNN]=200 GeV. PHYSICAL REVIEW LETTERS 2007; 98:062301. [PMID: 17358934 DOI: 10.1103/physrevlett.98.062301] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2006] [Indexed: 05/14/2023]
Abstract
We present the scaling properties of Lambda, Xi, and Omega in midrapidity Au+Au collisions at the Brookhaven National Laboratory Relativistic Heavy Ion Collider at sqrt[s_{NN}]=200 GeV. The yield of multistrange baryons per participant nucleon increases from peripheral to central collisions more rapidly than that of Lambda, indicating an increase of the strange-quark density of the matter produced. The strange phase-space occupancy factor gamma_{s} approaches unity for the most central collisions. Moreover, the nuclear modification factors of p, Lambda, and Xi are consistent with each other for 2<p_{T}<5 GeV/c in agreement with a scenario of hadron formation from constituent quark degrees of freedom.
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