401
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Zhu S, Ramaswamy HS, Marcotte M, Chen C, Shao Y, Le Bail A. Evaluation of thermal properties of food materials at high pressures using a dual-needle line-heat-source method. J Food Sci 2007; 72:E49-56. [PMID: 17995833 DOI: 10.1111/j.1750-3841.2006.00243.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Thermal properties of food systems at high pressure (HP) are important in the design and operation of HP processing equipment. Available techniques for thermal property evaluation under HP conditions are still very limited. In this study, a dual-needle line-heat-source (DNL) device was installed in an HP vessel to evaluate thermal conductivity (k), diffusivity (alpha), and volumetric heat capacity (C(pV)) of foods at high pressure. The DNL probe was calibrated using glycerin (0.1 MPa) and 2% (w/w) agar gel (0.1 to 350 MPa) at 5 and 25 degrees C. Calibration results showed a good correlation with the reference data of pure water: R(2)= 0.966 for thermal conductivity and R(2)= 0.837 for diffusivity, and a small standard deviation of relative error (3.18%) for the volumetric heat capacity. Fresh potato and cheddar cheese were used as test samples at 5 degrees C at selected pressure levels (0.1 to 350 MPa). The potato samples gave thermal properties very close to those of pure water, but much higher than those of the cheese. The k and alpha values of both potato and cheese increased with pressure and a 2nd-order polynomial well fitted their pressure dependency. The volumetric heat capacity data did not show a clear pressure-dependency trend. The experimental system worked well for the evaluation of thermal properties at pressures up to 350 MPa.
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402
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Mukhopadhyay S, Almehed D, Garg U, Frauendorf S, Li T, Rao PVM, Wang X, Ghugre SS, Carpenter MP, Gros S, Hecht A, Janssens RVF, Kondev FG, Lauritsen T, Seweryniak D, Zhu S. From chiral vibration to static chirality in (135)Nd. PHYSICAL REVIEW LETTERS 2007; 99:172501. [PMID: 17995322 DOI: 10.1103/physrevlett.99.172501] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2007] [Indexed: 05/25/2023]
Abstract
Electromagnetic transition probabilities have been measured for the intraband and interband transitions in the two sequences in the nucleus (135)Nd that were previously identified as a composite chiral pair of rotational bands. The chiral character of the bands is affirmed and it is shown that their behavior is associated with a transition from a vibrational into a static chiral regime.
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403
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Guo Y, Zhu N, Zhu S, Deng C. Molecular phylogenetic diversity of bacteria and its spatial distribution in composts. J Appl Microbiol 2007; 103:1344-54. [PMID: 17897238 DOI: 10.1111/j.1365-2672.2007.03367.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS To investigate microbial diversity of swine manure composts in the initial stage and the spatial distribution due to gradient effect. METHODS AND RESULTS Samples in different locations of a composting pile were taken and analysed by using a culture-independent approach. Total community DNA was extracted and bacterial 16S rRNA genes were subsequently amplified, cloned, restriction fragment length polymorphism-screened and sequenced. Thirty-three unique sequence types were found among the 110 analysed positive clones from superstratum sample; 56 among 122 from middle-level sample and 32 among 114 from substrate sample, respectively. The sequences related to Clostridium sp. were most common in the composts. One hundred and thirteen out of 121 16S rDNA sequence types displayed homology with those in the GenBank database. Seven 16S rDNA sequence types were not closely related to any known species. The middle-level sample had the highest microbial diversity, containing unique sequences related to Lactosphaera pasteurii, Firmicutes sp., Aerococcus sp., Megasphaera sp. and Stenotrophomonas sp. CONCLUSIONS Pile temperature significantly affected microbial community in the initial stage of the composting. Microbial community in different locations is quite different resulting from gradient effect. SIGNIFICANCE AND IMPACT OF THE STUDY Results of this study reveal high bacterial diversity in manure composts, and provide molecular evidence to support gradient effect on microbial diversity in initial stage as well.
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404
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Dommels YEM, Butts CA, Zhu S, Davy M, Martell S, Hedderley D, Barnett MPG, McNabb WC, Roy NC. Characterization of intestinal inflammation and identification of related gene expression changes in mdr1a(-/-) mice. GENES AND NUTRITION 2007; 2:209-23. [PMID: 18850176 DOI: 10.1007/s12263-007-0051-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Accepted: 01/24/2007] [Indexed: 12/31/2022]
Abstract
Multidrug resistance targeted mutation (mdr1a (-/-) ) mice spontaneously develop intestinal inflammation. The aim of this study was to further characterize the intestinal inflammation in mdr1a (-/-) mice. Intestinal samples were collected to measure inflammation and gene expression changes over time. The first signs of inflammation occurred around 16 weeks of age and most mdr1a (-/-) mice developed inflammation between 16 and 27 weeks of age. The total histological injury score was the highest in the colon. The inflammatory lesions were transmural and discontinuous, revealing similarities to human inflammatory bowel diseases (IBD). Genes involved in inflammatory response pathways were up-regulated whereas genes involved in biotransformation and transport were down-regulated in colonic epithelial cell scrapings of inflamed mdra1 (-/-) mice at 25 weeks of age compared to non-inflamed FVB mice. These results show overlap to human IBD and strengthen the use of this in vivo model to study human IBD. The anti-inflammatory regenerating islet-derived genes were expressed at a lower level during inflammation initiation in non-inflamed colonic epithelial cell scrapings of mdr1a (-/-) mice at 12 weeks of age. This result suggests that an insufficiently suppressed immune response could be crucial to the initiation and development of intestinal inflammation in mdr1a (-/-) mice.
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405
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Zhu S, Korzh V, Gong Z, Low BC. RhoA prevents apoptosis during zebrafish embryogenesis through activation of Mek/Erk pathway. Oncogene 2007; 27:1580-9. [PMID: 17873909 DOI: 10.1038/sj.onc.1210790] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
RhoA small GTPase, as a key regulator for actin cytoskeletal rearrangement, plays pivotal roles during morphogenesis, cytokinesis, phagocytosis and cell migration, but little is known about its signaling mechanism that controls cell survival in vivo. Using zebrafish as a model, we show that non-overlapping antisense morpholinos that block either translation or splicing of rhoA lead to extensive apoptosis during embryogenesis, resulting in overall reduction of body size and body length. These defects are associated with reduced activation of growth-promoting Erk and decreased expression of anti-apoptotic bcl-2. Moreover, ectopic expression of rhoA, Mek or BCL-2 mRNA rescues such phenotypes. Consistently, combined suppression of RhoA and Mek/Erk or Bcl-2 pathways by sub-optimal dose of rhoA morpholino and pharmacological inhibitors for either Mek (U0126) or Bcl-2 (HA 14-1) can induce developmental abnormalities and enhanced apoptosis, similar to those caused by effective RhoA knockdown. Furthermore, U0126 abrogates the rescue by RhoA and MEK but not BCL-2. In contrast, HA 14-1 effectively abolishes all functional rescues by RhoA, MEK or BCL-2, supporting that RhoA prevents apoptosis by activation of Mek/Erk pathway and requiring Bcl-2. These findings reveal an important genetic and functional relationship between RhoA with Mek/Erk and Bcl-2 for cell survival control during embryogenesis.
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406
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Li Y, Zhu S, Hahn RG. The kinetics of Ringer's solution in young and elderly patients during induction of general anesthesia with propofol and epidural anesthesia with ropivacaine. Acta Anaesthesiol Scand 2007; 51:880-7. [PMID: 17635395 DOI: 10.1111/j.1399-6576.2007.01351.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Different fluid regimens are often adopted for elderly patients, but it is not known whether they handle infused fluids differently during the induction of anesthesia than young patients. METHODS Mean arterial pressure (MAP), plasma dilution (based on hemoglobin) and volume kinetics were assessed during an intravenous (i.v.) infusion of 1000 ml of lactated Ringer's solution over exactly 60 min in 29 patients given general anesthesia with propofol (15 < 65 years of age, and 14 > 65 years old) and in 16 patients receiving lumbar epidural anesthesia with titrated doses of ropivacaine (7 patients < 65 years of age and 9 > 65 years old). RESULTS General anesthesia caused a greater decrease in MAP than epidural anesthesia (mean 15% vs. 9%; P < 0.001) and was followed by a more pronounced plasma dilution (30% vs. 18%; P < 0.001); the maximum values reaching 50%. The fluid-induced hemodilution increased after the onset of anesthesia. The distribution rate constant (k(t)), which governs the preference for infused fluid to retain the plasma, was significantly reduced, with the lowest values being reached during general anesthesia (P < 0.002). However, only the reduction of MAP, and not the patient's age group or the type of anesthesia per se, had a statistically significant influence on k(t) after the induction. CONCLUSION Induction of anesthesia greatly increases fluid-induced hemodilution, the magnitude of which can be expressed as an acute reduction of the distribution rate constant for infused fluid. The post-induction value of this parameter was closely associated with MAP but not with the patient's age.
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407
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Kay HH, Zhu S, Tsoi S. Hypoxia and Lactate Production in Trophoblast Cells. Placenta 2007; 28:854-60. [PMID: 17275903 DOI: 10.1016/j.placenta.2006.11.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2006] [Revised: 11/14/2006] [Accepted: 11/15/2006] [Indexed: 12/20/2022]
Abstract
The etiology of preeclampsia is unknown but is thought to be related to hypoxia in the placenta. We previously reported that the enzyme lactate dehydrogenase (LDH) has increased activity and gene expression in placentas from preeclamptic pregnancies [Tsoi SCM, Zheng J, Xu F, Kay HH. Differential expression of lactate dehydrogenase isozymes (LDH) in human placenta with high expression of LDH-A(4) isozyme in the endothelial cells of pre-eclampsia villi. Placenta 2001;22:317-22]. LDH is responsible for pyruvate conversion to lactate through glycolysis. In this study, we further investigated the role of hypoxia in primary trophoblast cells and a cultured cell line, JEG3 cells, to obtain a better understanding of how it affects the activities of lactate dehydrogenase, lactate production and regulatory genes, as a possible model for preeclampsia. Primary trophoblast cells and JEG3 cells were cultured under 1% oxygen. At 6, 12 and 24h, cells were analyzed for LDHA and LDHB isozyme activities, mRNA and protein expression compared to standard culture conditions. Lactate was measured from cell medium. The hypoxia inducible transcription factor (HIF-1alpha) protein expression was confirmed by western blot. Two lactate transporters (MCT1 and MCT4) mRNA and protein expression were also studied under hypoxia. Finally, lactate was measured in plasma obtained from patients with severe preeclampsia. Under hypoxic conditions, LDHA mRNA is increased in primary trophoblast cells and JEG3 cells. The HIF-1alpha protein expression is higher in hypoxia-treated JEG3 cells than control. LDHA isozyme activity and its protein expression are increased most significantly at 24h of culture under hypoxia. However, LDHB protein is unchanged while its mRNA is decreased. Lactate secretion from JEG3 cells under hypoxia is increased, as is the lactate levels in the plasma from preeclampsia patients. Of the two lactate transporters studied, MCT4 mRNA and protein level are increased under hypoxia. Our findings support the role of hypoxia in inducing HIF-1alpha activity in trophoblasts and increasing LDH transcription as well as its activity. Higher levels of lactate are produced and secreted which may contribute to the higher lactate levels in plasma of preeclamptic patients. These mechanisms may be important in the pathophysiology of preeclampsia.
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408
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Seweryniak D, Carpenter MP, Gros S, Hecht AA, Hoteling N, Janssens RVF, Khoo TL, Lauritsen T, Lister CJ, Lotay G, Peterson D, Robinson AP, Walters WB, Wang X, Woods PJ, Zhu S. Single-neutron states in (101)Sn. PHYSICAL REVIEW LETTERS 2007; 99:022504. [PMID: 17678218 DOI: 10.1103/physrevlett.99.022504] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2007] [Indexed: 05/16/2023]
Abstract
The first data on the relative single-particle energies outside the doubly magic (100)Sn nucleus were obtained. A prompt 171.7(6) keV gamma-ray transition was correlated with protons emitted following the beta decay of (101)Sn and is interpreted as the transition between the single-neutron g(7/2) and d(5/2) orbitals in (101)Sn. This observation provides a stringent test of current nuclear structure models. The measured nug(7/2)-nud(5/2) energy splitting is compared with values calculated using mean-field nuclear potentials and is used to calculate low-energy excited states in light Sn isotopes in the framework of the shell model. The correlation technique used in this work offers possibilities for future, more extensive spectroscopy near (100)Sn.
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409
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Zhu S, Pudney PDA, Heppenstall-Butler M, Butler MF, Ferdinando D, Kirkland M. Interaction of the acid soap of triethanolamine stearate and stearic acid with water. J Phys Chem B 2007; 111:1016-24. [PMID: 17266256 DOI: 10.1021/jp0659047] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Stearic acid and triethanolamine (TEA) in a molar ratio of 2:1 were mixed in aqueous solution at 80 degrees C and subsequently cooled to ambient temperature. The structural evolution of the resultant sample during storage was characterized by using light microscopy, Cryo-SEM, differential scanning calorimetery, pH, infrared spectroscopy, elemental analysis, and simultaneous small and wide-angle X-ray diffraction. It was found that a lamellar liquid crystalline phase was formed when stearic acid and TEA solution were mixed at 80 degrees C and multilamellar spheres of a few microns diameter were formed initially after cooling. A hydrolysis reaction (i.e., the reverse reaction of neutralization between stearic acid and TEA) occurred thereafter that caused the breakdown of the lamellar gel phase and the formation of platelet stearic acid crystals. Three polymorphs of stearic acid (defined following previous work as the A, C, and E forms) were formed as the result of hydrolysis reaction, which gave rise to a strong optically pearlescent appearance.
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410
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Li F, Zhu S, Liu Y, Chen G, Chi L, Qu F. Hyperdense intracranial epidermoid cysts: a study of 15 cases. Acta Neurochir (Wien) 2007; 149:31-9; discussion 39. [PMID: 17151831 DOI: 10.1007/s00701-006-1060-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2006] [Accepted: 10/05/2006] [Indexed: 11/30/2022]
Abstract
BACKGROUND Although intracranial epidermoid cysts generally appear as hypodense lesions on CT scans, occasionally, they may appear hyperdense, making diagnosis difficult. The aim was to study clinical features and possible pathogenesis of hyperdense intracranial epidermoid cysts (HIECs). METHODS Fifteen patients with HIECs were surgically treated in our department during a 21-year period (1985 up to 2005). We reviewed each patient's clinical records, radiological findings, operative reports, and pathological examinations, along with a review of the literature. FINDINGS The incidence of HIECs in our series was approximately 3.02%, with female predominance. The average age was 32 years and the average duration of complaints was nine months. The most common location was the parasellar area (6 cases), followed by cerebellum (4 cases), clival region (3 cases), cerebello-pontine angle (1 case) and lateral ventricle (1 case). Gross-total excision of the tumor was achieved in ten patients (66.7%). Four (26.7%) patients underwent subtotal resection; and one (6.6%) patient underwent partial resection. Aseptic meningitis that occurred postoperatively in two cases was controlled by lumbar drainage. CONCLUSIONS Recurrent leakage of the irritating cyst contents and subsequent chemical inflammatory response may be responsible for the high-density on CT scans and the cystic nature. A correct histological diagnosis is important because, in contrast to typical ECs and other lesions, HIECs are more prone to spread intra-operatively and result in severe aseptic meningitis.
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411
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Rossi S, Luckham PF, Zhu S, Briscoe BJ, Tadros TF. Influence of Low Molecular Weight Polymers on the Rheology of Bentonite Suspensions. ACTA ACUST UNITED AC 2006. [DOI: 10.2516/ogst:1997019] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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412
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Zhu S, Gao B. Molecular characterization of a new scorpion venom lipolysis activating peptide: Evidence for disulfide bridge-mediated functional switch of peptides. FEBS Lett 2006; 580:6825-36. [PMID: 17141763 DOI: 10.1016/j.febslet.2006.11.040] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2006] [Revised: 11/13/2006] [Accepted: 11/16/2006] [Indexed: 11/16/2022]
Abstract
Venoms from scorpions contain extremely rich bioactive peptides that often carry diverse functions and are presumably needed to achieve synergistic effects for rapidly immobilizing prey and defending themselves. BotLVP1 is a unique heterodimer protein recently found in the scorpion Buthus occitanus tunetanus venom that is structurally related to scorpion toxins affecting sodium channels (NaScTxs) but exhibits adipocyte lipolysis activity. We have isolated and identified two cDNA clones encoding subunits alpha and beta of a BotLVP1-like peptide (named BmLVP1) from the Chinese scorpion Buthus martensii venom gland and determined the first complete gene structure of this subfamily. These results highlight a genetic link between these lipolysis activating peptides and NaScTxs. Comparison of cDNA and genomic sequences combined with protein structural and functional analysis provides evidence supporting the existence of RNA editing mechanism in scorpion venom glands, which could mediate functional switch of BmLVP1 gene, from adipocyte lipolysis to neurotoxicity, by altering the wrapper disulfide bridge (WDB) pattern of the peptides.
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413
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Horvath S, Zhang B, Carlson M, Lu KV, Zhu S, Felciano RM, Laurance MF, Zhao W, Qi S, Chen Z, Lee Y, Scheck AC, Liau LM, Wu H, Geschwind DH, Febbo PG, Kornblum HI, Cloughesy TF, Nelson SF, Mischel PS. Analysis of oncogenic signaling networks in glioblastoma identifies ASPM as a molecular target. Proc Natl Acad Sci U S A 2006; 103:17402-7. [PMID: 17090670 PMCID: PMC1635024 DOI: 10.1073/pnas.0608396103] [Citation(s) in RCA: 474] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Glioblastoma is the most common primary malignant brain tumor of adults and one of the most lethal of all cancers. Patients with this disease have a median survival of 15 months from the time of diagnosis despite surgery, radiation, and chemotherapy. New treatment approaches are needed. Recent works suggest that glioblastoma patients may benefit from molecularly targeted therapies. Here, we address the compelling need for identification of new molecular targets. Leveraging global gene expression data from two independent sets of clinical tumor samples (n = 55 and n = 65), we identify a gene coexpression module in glioblastoma that is also present in breast cancer and significantly overlaps with the "metasignature" for undifferentiated cancer. Studies in an isogenic model system demonstrate that this module is downstream of the mutant epidermal growth factor receptor, EGFRvIII, and that it can be inhibited by the epidermal growth factor receptor tyrosine kinase inhibitor Erlotinib. We identify ASPM (abnormal spindle-like microcephaly associated) as a key gene within this module and demonstrate its overexpression in glioblastoma relative to normal brain (or body tissues). Finally, we show that ASPM inhibition by siRNA-mediated knockdown inhibits tumor cell proliferation and neural stem cell proliferation, supporting ASPM as a potential molecular target in glioblastoma. Our weighted gene coexpression network analysis provides a blueprint for leveraging genomic data to identify key control networks and molecular targets for glioblastoma, and the principle eluted from our work can be applied to other cancers.
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414
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Abstract
MicroRNAs (miRNAs) are approximately 22 nucleotide non-coding RNA molecules that regulate gene expression post-transcriptionally. Although aberrant expression of miRNAs in various human cancers suggests a role for miRNAs in tumorigenesis, it remains largely unclear as to whether knockdown of a specific miRNA affects tumor growth. In this study, we profiled miRNA expression in matched normal breast tissue and breast tumor tissues by TaqMan real-time polymerase chain reaction miRNA array methods. Consistent with previous findings, we found that miR-21 was highly overexpressed in breast tumors compared to the matched normal breast tissues among 157 human miRNAs analysed. To better evaluate the role of miR-21 in tumorigenesis, we transfected breast cancer MCF-7 cells with anti-miR-21 oligonucleotides and found that anti-miR-21 suppressed both cell growth in vitro and tumor growth in the xenograft mouse model. Furthermore, this anti-miR-21-mediated cell growth inhibition was associated with increased apoptosis and decreased cell proliferation, which could be in part owing to downregulation of the antiapoptotic Bcl-2 in anti-miR-21-treated tumor cells. Together, these results suggest that miR-21 functions as an oncogene and modulates tumorigenesis through regulation of genes such as bcl-2 and thus, it may serve as a novel therapeutic target.
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415
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Zhu S, Gao B. Molecular characterization of a possible progenitor sodium channel toxin from the Old World scorpion Mesobuthus martensii. FEBS Lett 2006; 580:5979-87. [PMID: 17054952 DOI: 10.1016/j.febslet.2006.09.071] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Revised: 09/26/2006] [Accepted: 09/27/2006] [Indexed: 11/18/2022]
Abstract
Toxins affecting sodium channels widely exist in the venoms of scorpions throughout the world. These molecules comprise an evolutionarily related peptide family with three shared features including conserved three-dimensional structure and gene organization, and similar function. Based on different pharmacological profiles and binding properties, scorpion sodium channel toxins are divided into alpha- and beta-groups. However, their evolutionary relationship is not yet established. Here, we report a gene isolated from the venom gland of scorpion Mesobuthus martensii which encodes a novel sodium channel toxin-like peptide of 64 amino acids, named Mesotoxin. The Mesotoxin gene is organized into three exons and two introns with the second intron location conserved across the family. This peptide is unusual in that it has only three disulfides and a long cysteine-free tail with loop size and structural characteristics close to beta-toxins. Evolutionary analysis favors its basal position in the origin of scorpion sodium channel toxins as a progenitor. The discovery of Mesotoxin will assist investigations into the key issue regarding the origin and evolution of scorpion toxins.
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416
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Zhou W, Tan TT, Lim LEN, Zheng HY, Zhu S, Wang LM. Effect of femtosecond laser irradiation on structure of UV grade fused silica. OPTICS EXPRESS 2006; 14:9217-9222. [PMID: 19529303 DOI: 10.1364/oe.14.009217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A p-polarized femtosecond laser beam was used to irradiate a UV grade fused silica to create microchannels, which are useful for producing optical gratings or micro fluidics devices. The laser irradiated surface was characterized using optical microscope, stylus profiler, SEM, XRD and TEM. A special technique was used to protect the laser irradiated surfaces in preparing cross-sectional TEM samples. The XRD spectra and TEM observation reveal that structure of the fused silica remain amorphous after the femtosecond laser irradiation.
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417
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Tandel SK, Khoo TL, Seweryniak D, Mukherjee G, Ahmad I, Back B, Blinstrup R, Carpenter MP, Chapman J, Chowdhury P, Davids CN, Hecht AA, Heinz A, Ikin P, Janssens RVF, Kondev FG, Lauritsen T, Lister CJ, Moore EF, Peterson D, Reiter P, Tandel US, Wang X, Zhu S. K isomers in 254No: probing single-particle energies and pairing strengths in the heaviest nuclei. PHYSICAL REVIEW LETTERS 2006; 97:082502. [PMID: 17026297 DOI: 10.1103/physrevlett.97.082502] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2006] [Indexed: 05/12/2023]
Abstract
We have identified two isomers in 254No, built on two- and four-quasiparticle excitations, with quantum numbers K pi = 8- and (14+), as well as a low-energy 2-quasiparticle Kpi = 3+ state. The occurrence of isomers establishes that K is a good quantum number and therefore that the nucleus has an axial prolate shape. The 2-quasiparticle states probe the energies of the proton levels that govern the stability of superheavy nuclei, test 2-quasiparticle energies from theory, and thereby check their predictions of magic gaps.
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418
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Meng J, Shi Y, Zhao X, Guo S, Wang H, Zheng Y, Tang R, Feng G, Gu N, Liu H, Zhu S, He L. No association between the genetic polymorphisms in the RTN4R gene and schizophrenia in the Chinese population. J Neural Transm (Vienna) 2006; 114:249-54. [PMID: 16897606 DOI: 10.1007/s00702-006-0538-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2006] [Accepted: 06/18/2006] [Indexed: 11/24/2022]
Abstract
The RTN4R gene is located in the 22q11 region and it encodes a subunit of the receptor complex (RTN4R-p75NTR) which results in neuronal growth inhibitory signals in response to Nogo-66, MAG or OMG signaling. Previous studies have suggested that RTN4R might act as a potential candidate for schizophrenia susceptibility loci. We genotyped four SNPs within the gene and conducted a case-control study and TDT analysis, involving 707 schizophrenic patients, 689 controls and 372 unrelated small nuclear families with schizophrenic offspring in the Chinese population. We examined allele and genotype frequencies and haplotype distributions in both family- and nonfamily-based samples. Our results suggest that there is no significant association between the genetic polymorphisms and schizophrenia in the Han Chinese population.
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419
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Yoon K, Zhu S, Ewing SJ, Smart RC. Decreased survival of C/EBP beta-deficient keratinocytes is due to aberrant regulation of p53 levels and function. Oncogene 2006; 26:360-7. [PMID: 16832342 DOI: 10.1038/sj.onc.1209797] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Recent studies have identified roles for C/EBPbeta in cellular survival and tumorigenesis, however, the mechanisms through which C/EBPbeta regulates these processes are not fully understood. Previously, we demonstrated that C/EBPbeta(-/-) mice are resistant to carcinogen-induced skin tumorigenesis and in response to topical carcinogen treatment display a 17-fold increase in keratinocyte apoptosis compared to wild-type mice. Here, we have investigated the mechanisms through which C/EBPbeta regulates apoptosis in response to carcinogenic stress. Analysis of carcinogen-treated C/EBPbeta(-/-) mouse skin revealed a striking increase in the number of p53 immunopositive keratinocytes in the epidermis of C/EBPbeta(-/-) mice compared to wild-type mice and this increase was temporally associated with a concomitant anomalous increase in apoptosis. The increased levels of p53 were functional as Mdm2, Bcl-2, C/EBPalpha and p21 were differentially regulated in the epidermis of carcinogen-treated C/EBPbeta(-/-) mice. The increase in p53 protein was not associated with an increase in p53 mRNA levels. To determine whether p53 is required for the increased apoptosis in C/EBPbeta(-/-) mice, C/EBPbeta/p53 compound knockout mice were generated. Carcinogen-treated C/EBPbeta/p53 compound knockout mice did not display increased apoptosis demonstrating p53 is required for the proapoptotic phenotype in C/EBPbeta(-/-) mice. Our results demonstrate that altered keratinocyte survival in C/EBPbeta(-/-) mice results from aberrant regulation of p53 protein and function and indicate C/EBPbeta has a role in the negative regulation of p53 protein levels in response to carcinogen-induced stress.
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420
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Zhu S, Le Bail A, Ramaswamy H. High-pressure differential scanning calorimetry: Comparison of pressure-dependent phase transition in food materials. J FOOD ENG 2006. [DOI: 10.1016/j.jfoodeng.2005.04.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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421
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Zhu S, le
Bail A, Ramaswamy HS, Chapleau N. Characterization of Ice Crystals in Pork Muscle Formed by Pressure-shift Freezing as Compared with Classical Freezing Methods. J Food Sci 2006. [DOI: 10.1111/j.1365-2621.2004.tb06346.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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422
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Xiang X, Zu XT, Zhu S, Wei QM, Zhang CF, Sun K, Wang LM. ZnO nanoparticles embedded in sapphire fabricated by ion implantation and annealing. NANOTECHNOLOGY 2006; 17:2636-2640. [PMID: 21727517 DOI: 10.1088/0957-4484/17/10/032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
ZnO nanoparticles were fabricated in sapphire (α-Al(2)O(3) single crystal) by Zn ion implantation (48 keV) at an ion fluence of 1 × 10(17) cm(-2) and subsequent thermal annealing in a flowing oxygen atmosphere. Transmission electron microscopy (TEM) analysis revealed that metallic Zn nanoparticles of 3-10 nm in dimensions formed in the as-implanted sample and that ZnO nanoparticles of 10-12 nm in dimensions formed after annealing at 600 °C. A broad absorption band, peaked at 280 nm, appeared in the as-implanted crystal, due to surface plasma resonance (SPR) absorption of metallic Zn nanoparticles. After annealing at 600 °C, ZnO nanoparticles resulted in an exciton absorption peak at 360 nm. The photoluminescence (PL) of the as-implanted sample was very weak when using a He-Cd 325 nm line as the excitation source. However, two emission peaks appeared in the PL spectrum of ZnO nanopraticles, i.e., one ultraviolet (UV) peak at 370 nm and the other a green peak at 500 nm. The emission at 500 nm is stronger and has potential applications in green/blue light-emitting devices.
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Heng KWJ, Lee AHP, Zhu S, Tham KY, Seow E. Helmet use and bicycle-related trauma in patients presenting to an acute hospital in Singapore. Singapore Med J 2006; 47:367-72. [PMID: 16645684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
INTRODUCTION To describe the relationship between bicycle helmet use and injury pattern sustained by patients presenting to an emergency department (ED) in Singapore for bicycle-related trauma. METHODS Data was collected from all individuals treated for bicycle-related trauma between September 1, 2004 and May 31, 2005 using a closed-ended questionnaire. RESULTS 160 bicyclists with mean age of 34.4 years (range 10 to 89 years) were surveyed. Among them, 80 percent were male and 30.6 percent were non-residents. Helmets were worn by 10.6 percent of the patients. Alcohol was clinically detected in 11.3 percent of bicyclists. There was no difference in bicycle helmet use between Singaporeans and non-residents (p-value is 0.275). However, compared to younger bicyclists, bicyclists aged 30 years or older (p-value is less than 0.05), and compared to recreational or sport bicyclists, those who commute by bicycle, tended not to wear helmets (p-value is less than 0.01). Compared to Singaporeans (p-value is less than 0.05), non-residents and bicyclists aged 30 years or older (p-value is 0.011) believed that helmets did not protect against head injury. Comparing the helmeted group with the non-helmeted group, injury patterns by body region were: head injury 5.9 percent versus 40.0 percent (p-value is less than 0.01); facial injury 5.9 percent versus 37.1 percent (p-value is less than 0.05). Not wearing a helmet, being hit by a motor vehicle and age were significantly associated with higher injury severity scores, after adjusting for several potential confounding factors. CONCLUSION Bicycle helmet use was low in our sample of injured patients. When worn, protection against injury was demonstrated. A campaign to promote use of bicycle helmets should be targeted at non-residents and older bicyclists. Authorities should consider compulsory helmet laws for bicyclists and expanding anti-drunk driving campaigns to target alcohol-intoxicated bicyclists.
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Xia G, Kumar SR, Stein JP, Singh J, Krasnoperov V, Zhu S, Hassanieh L, Smith DL, Buscarini M, Broek D, Quinn DI, Weaver FA, Gill PS. EphB4 receptor tyrosine kinase is expressed in bladder cancer and provides signals for cell survival. Oncogene 2006; 25:769-80. [PMID: 16205642 DOI: 10.1038/sj.onc.1209108] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We sought to evaluate the biological function of the receptor tyrosine kinase EphB4 in bladder cancer. All of the nine bladder cancer cell lines examined express EphB4 and the receptor could be phosphorylated following stimulation with its cognate ligand, EphrinB2. Out of the 15 fresh bladder cancer specimens examined, 14 expressed EphB4 with a mean sevenfold higher level of expression compared to adjacent normal urothelium. EphB4 expression was regulated by several mechanisms: EPHB4 gene locus was amplified in 27% tumor specimens and 33% cell lines studied; inhibition of EGFR signaling downregulated EphB4 levels; and forced expression of wild-type p53 reduced EphB4 expression. EphB4 knockdown using specific siRNA and antisense oligodeoxynucleotides molecules led to a profound inhibition in cell viability associated with apoptosis via activation of caspase-8 pathway and downregulation of antiapoptotic factor, bcl-xl. Furthermore, EphB4 knockdown significantly inhibited tumor cell migration and invasion. EphB4 knockdown in an in vivo murine tumor xenograft model led to a nearly 80% reduction in tumor volume associated with reduced tumor proliferation, increased apoptosis and reduced tumor microvasculature. EphB4 is thus a potential candidate as a predictor of disease outcome in bladder cancer and as target for novel therapy.
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Rainovski G, Pietralla N, Ahn T, Lister CJ, Janssens RVF, Carpenter MP, Zhu S, Barton CJ. Stabilization of nuclear isovector valence-shell excitations. PHYSICAL REVIEW LETTERS 2006; 96:122501. [PMID: 16605899 DOI: 10.1103/physrevlett.96.122501] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2005] [Indexed: 05/08/2023]
Abstract
Excited states in 138Ce have been studied via the 12C(138Ce, 138Ce*) Coulomb excitation reaction at 480 MeV. Relative cross sections have been determined from the gamma-ray yields observed with Gammasphere. The E2 and M1 strength distributions between the lowest six 2+ states up to 2.7 MeV enables us to identify the 2(4)+ state in 138Ce as the dominant fragment of the one-phonon 2(1,ms)+ mixed-symmetry state. Mixing between this level and a nearby isoscalar state is observed and is more than 4 times larger than in the neighboring isotone 136Ba. This is direct evidence that the stability of mixed-symmetry states strongly depends on the underlying subshell structure.
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