bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment of aged biodegradable polymer‐coated nano‐zero‐valent iron for degradation of hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine (RDX)
Authors: Xiao Ru , Wazne Mahmoud 
Published: July 2012

AbstractBACKGROUND: This study reports on the effects of aging on suspension behavior of biodegradable polymer‐coated nano‐zero‐valent iron (nZVI) and its degradation rates of hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine (RDX) under reductive conditions. The polymers investigated included guar gum, potato starch, alginic acid (AA), and carboxymethyl cellulose (CMC). Polymer coating was used to mitigate nZVI delivery hindrance for in situ treatment of RDX‐contaminated groundwater.RESULTS: The RDX degradation rates by bare nZVI and starch‐coated nZVI suspensions were least affected by aging although these suspensions exhibited the least favorable dispersion behavior. CMC, AA, and guar gum coating improved nZVI rates of degradation of RDX but these rates decreased upon aging. The best suspension stability upon aging was achieved by CMC and AA. Guar gum with loadings rates one order of magnitude lower than that of CMC and AA achieved good iron stabilization but significantly higher RDX degradation rates.CONCLUSION: It is demonstrated that both migration and reactivity of polymer‐stabilized nZVI should be explicitly evaluated over a long period before application in the field. Guar gum coated nZVI appeared best suited for in situ application because it maintained good suspension stability, with RDX degradation rates least affected by aging compared with the other polymers tested. © 2012 Society of Chemical Industry
Determining the limiting reaction in anaerobic digestion processes. How has this been tackled?
Authors: Donoso‐Bravo Andres , Mairet Francis 
Published: July 2012

AbstractThe rate‐limiting step concept has been widely used in anaerobic digestion processes as well as in many different biological processes. Sometimes it is described as part of the study introduction, but many times is used to support the specific objectives of the work. However, there is no clear consensus of how to define this step or how to determine it. This review presents a critical revision of several methods and procedures proposed to determine the rate‐limiting step in the anaerobic digestion field. The review is structured as follows: first, the justification of this revision is presented, followed by the very basic original definition and the latest applications in determining the rate‐limiting step. It ends with a discussion about the existing methodologies and the possible directions for addressing this issue. Different experimental approaches have been used for determining the rate‐limiting step which, in general terms, can be grouped into two procedures: steady states and batch test evaluation. Modeling applications have rarely been employed despite them allowing a more detailed picture of the anaerobic digestion system Copyright © 2012 Society of Chemical Industry
Sexually Dimorphic Levels of Color Trait Integration and the Resolution of Sexual Conflict inLakeMalawi Cichlids
Authors: BRZOZOWSKI FRANCES , ROSCOE JENNIFER , PARSONS KEVIN , ALBERTSON CRAIG 
Published: July 2012

ABSTRACTEastAfrican cichlids are renowned for their propensity to radiate, and variation in color patterns accounts for much of endemic cichlid diversity. Sexual dimorphism in color among cichlid species likely represents the outcome of different selective regimes acting on each sex, and is a classic example of sexual conflict. It is generally assumed that this conflict has been mitigated through the evolution of sex‐linked color polymorphisms. Here, we propose that the evolution of sex‐specific differences in levels of color trait integration may represent an additional mechanism through which sexual conflict has been resolved in this group. Specifically, we predict: (1) that general patterns of integration are influenced by early developmental events and thus conserved across sexes and (2) that male color is less integrated than females, and thus more evolvable in terms of producing an elaborate palette (i.e., in response to sexual selection), whereas female color is more integrated, facilitating wholesale shifts in color for background matching (i.e., in response to natural selection for crypsis). We tested these hypotheses using anF2design to compare the segregation of male and female color patterns. Both exploratory methods and hypothesis‐driven analyses of integration demonstrate that the covariance structure of color traits in males and females is distinct, and that males are significantly less integrated than females. We suggest that the ability of species to promote different levels, and to a lesser extent patterns, of phenotypic integration between males and females may have contributed to the evolutionary success of this group.J. Exp. Zool. (Mol. Dev. Evol.) 318:268–278, 2012. © 2012 Wiley Periodicals, Inc.
Disparate Igf1 Expression and Growth in the Fore‐ and Hind Limbs of a Marsupial Mammal (Monodelphis domestica)
Authors: SEARS KAREN E. , PATEL ANKIT , HÜBLER MERLA , CAO XIAOYI , VANDEBERG JOHN L. , ZHONG SHENG 
Published: July 2012

ABSTRACTProper regulation of growth is essential to all stages of life, from development of the egg into an embryo to the maintenance of normal cell cycle progression in adults. However, despite growth's importance to basic biology and health, little is known about how mammalian growth is regulated. In this study, we investigated the molecular basis of the highly disparate growth of opossum fore‐ and hind limbs in utero. We first used a novel, opossum‐specific microarray to identify several growth‐related genes that are differentially expressed in opossum fore‐ and hind limbs of comparable developmental stages. These genes included Igf1. Given Igf1's role in the growth of other systems, we further investigated the role of Igf1 in opossum limb growth. Supporting the microarray results, RT‐PCR indicated that Igf1 levels are approximately two times higher in opossum fore‐ than hind limbs. Consistent with this, while Igf1 transcripts were readily detectable in opossum forelimbs using whole‐mount in situ hybridization, they were not detectable in opossum hind limbs. Furthermore, opossum limbs treated with exogenous Igf1 protein experienced significantly greater cellular proliferation and growth than control limbs in vitro. Taken together, results suggest that the differential expression of Igf1 in developing opossum limbs contributes to their divergent rate of growth, and the unique limb phenotype of opossum newborns. This study establishes the opossum limb as a new mammalian model system for study of organ growth. J. Exp. Zool. (Mol. Dev. Evol.) 318:279–293, 2012. © 2012 Wiley Periodicals, Inc.
Differential Expression and Regulation of Angiopoietin‐3 in Mouse Uterus during Preimplantation Period
Authors: GUO BIN , ZHANG XUE‐MING , LI SHI‐JIE , TIAN XUE‐CHAO , WANG SHOU‐TANG , LI DANG‐DANG , LIU JU‐XIONG , YUE ZHAN‐PENG 
Published: July 2012

ABSTRACTAngiogenesis is necessary for successful implantation and decidualization. This study was to investigate the differential expression of angiopoietin‐3 (Ang‐3) in mouse uterus during early pregnancy and its regulation by steroid hormones using in situ hybridization and reverse transcription polymerase chain reaction (RT‐PCR). There was no detectable Ang‐3 mRNA signal on days 1–5 of pregnancy by in situ hybridization. On day 6 of pregnancy, a low level of Ang‐3 mRNA signal was seen in the primary decidua. Ang‐3 mRNA expression gradually increased on days 7 and 8 of pregnancy along with the development of decidua, and its expression scope was also expanded. The RT‐PCR result indicated that Ang‐3 mRNA expression was low on days 1–4 of pregnancy. On day 5, as embryo implanted, Ang‐3 mRNA was highly expressed in mouse uterus, and the expression gradually increased on days 6–8 of pregnancy, with peak level on day 8 of pregnancy. Similarly, Ang‐3 mRNA was also strongly expressed in decidualized cells under artificial decidualization. Compared with the delayed uterus, a high level of Ang‐3 mRNA expression was detected in activated implantation uterus by RT‐PCR. In the ovariectomized mouse uterus, Ang‐3 mRNA expression increased and reached the highest level at 12 hr after injection of estrogen, progesterone, and estrogen plus progesterone, respectively. These results suggest that Ang‐3 may play an important role during the process of mouse decidualization. Both estrogen and progesterone can induce the expression of Ang‐3 in ovariectomized mouse uterus. J. Exp. Zool. (Mol. Dev. Evol.) 318:316–324, 2012. © 2012 Wiley Periodicals, Inc.
Temporal Bone Arrangements in Turtles: An Overview
Authors: WERNEBURG INGMAR 
Published: July 2012

ABSTRACTThe temporal region of turtles is characterized by significant anatomical diversity. Turtles show a pure anapsid morphotype that exhibits various different marginal reductions known as emarginations. As a result of this diversity, turtles can be taken as a model by which to understand the processes that may have resulted in the highly debated anatomy of the amniote temporal region in general. In this review on almost forgotten literature, I summarize ten potential factors that may act on the skull to shape the temporal region of turtles. These are: (1) phylogenetic constraints, (2) skull weights, (3) type of food, (4) skull dimensions, (5) muscle bulging, (6) ear anatomy and jaw muscle bending mechanisms, (7) extent and nature of muscle attachment sites, (8) internal forces within the jaw adductor chamber, (9) environmental pressure, and (10) neck bending mechanisms. Particular focus is laid on the interrelationship of the jaw musculature and the dermatocranial armour, which were assumed to influence each other to a certain degree. In the literature, cranial dimensions were assumed to influence temporal bone formation within major tetrapod groups. Among these, turtles seem to represent a kind of intermixture, a phenomenon that may be reflected in their specific anatomy. The references presented should be understood as product of the scientific environment in which they developed and the older literature does not always insist current empirical demands. However, the intuitive and creative ideas and the comprehensive anatomical considerations of these authors may inspire future studies in several fields related to this topic. J. Exp. Zool. (Mol. Dev. Evol.) 318:235–249, 2012. © 2012 Wiley Periodicals, Inc.
Spermiogenesis in the Australian cockatiel Nymphicus hollandicus
Authors: Lovas Erica M. , Filippich Lucio J. , Johnston Stephen D. 
Published: July 2012

AbstractInformation on the ultrastructure of parrot spermatids and spermatozoa is limited to only four species with no comprehensive study of spermiogenesis conducted within the order Psittaciformes. The present study was undertaken to describe the development of the cockatiel spermatid using electron microscopy. Four phases of spermatid maturation were documented on the basis of nuclear morphology, development of the acrosome, perforatorium, and axial filament. These phases included 1) round nuclei, 2) irregular nuclei, 3) elongated nuclei with granular chromatin, and 4) elongated nuclei with homogenous chromatin. While development of the cockatiel spermatid was comparable to that of other domestic avian species, we have noted the hollow nature of some chromatin granules, an abnormal formation of the axoneme, the absence of the fibrous sheath around the axoneme of the principal piece, and the absence of an annulus. J. Morphol. , 2012. © 2012 Wiley Periodicals, Inc.
Kefir inhibits 3T3‐L1 adipocyte differentiation through down‐regulation of adipogenic transcription factor expression
Authors: Ho Jin‐Nyoung , Choi Jae‐Woo , Lim Won‐Chul , Kim Mi‐Kyoung , Lee In‐Young , Cho Hong‐Yon 
Published: July 2012

AbstractBACKGROUND: Kefir, a traditional fermented milk composed of microbial symbionts, is reported to have various health benefits such as anti‐tumour, anti‐inflammatory, anti‐neoplastic and pro‐digestive effects. In this study, to elucidate the effects of kefir on adipocyte differentiation and lipid accumulation, three fractions were prepared from kefir culture broth. The inhibitory effects of kefir liquid culture broth fraction (Fr‐1), soluble fraction (Fr‐2) and insoluble fraction (Fr‐3), prepared by sonication of kefir solid culture broth, on adipocyte differentiation in 3T3‐L1 preadipocytes were examined.RESULTS: Fr‐3 (0.1 mg mL−1) significantly decreased lipid accumulation and glycerol‐3‐phosphate dehydrogenase (GPDH) activity by 60 and 68% respectively without affecting cell viability. In addition, Fr‐3 treatment down‐regulated the mRNA expression of adipogenic transcription factors including C/EBPα (32%), PPARγ (46%) and SREBP‐1c (34%) during adipocyte differentiation compared with untreated control cells. The mRNA expression of adipocyte‐specific genes (aP2, FAS and ACC) was also clearly decreased.CONCLUSION: The results suggest that the insoluble fraction of kefir (Fr‐3) mediates anti‐adipogenic effects through the inhibition of adipocyte differentiation, partly via suppression of the C/EBPα‐, SREBP‐1c‐ and PPARγ‐dependent pathways. © 2012 Society of Chemical Industry
Association of life threat and betrayal with posttraumatic stress disorder symptom severity
Authors: Kelley Lance P. , Weathers Frank W. , Mason Elizabeth A. , Pruneau Genevieve M. 
Published: July 2012

AbstractThe Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.; DSM‐IV‐TR; American Psychiatric Association [APA], 2000) emphasizes life threat as the defining feature of psychological trauma. Recent theoretical and empirical work, however, indicates the need to identify and evaluate other key aspects of trauma. Betrayal has been proposed as a pertinent, distinct, and complementary factor that can explain effects of trauma not accounted for by life threat alone. This study examined the relationship between injury, perceived life threat (PLT), and betrayal with posttraumatic stress disorder (PTSD) symptom severity. Trauma‐exposed college students (N = 185) completed self‐report measures of trauma exposure and PTSD, as well as items regarding life threat, betrayal, and level of medical care received. In hierarchical regressions incorporating injury, PLT, and betrayal, betrayal was associated with all PTSD symptom clusters and PTSD total severity (f2 = .08), whereas PLT was associated with hyperarousal (f2 = .05) and PTSD total (f2 = .03), and injury had no association with PTSD symptoms. In a revised model with trauma type as an additional variable, betrayal was associated with avoidance (f2 = .03), numbing (f2 = .04), and PTSD total (f2 = .03), whereas PLT was associated with reexperiencing (f2 = .04), hyperarousal (f2 = .04), and PTSD total (f2 = .03), and injury was associated with avoidance (f2 = .03). These findings support the idea that betrayal is a core dimension of psychological trauma that may play an important role in the etiology of PTSD.
Polymer Micelles for Delayed Release of Therapeutics from Drug‐Releasing Surfaces with Nanotubular Structures
Authors: Aw Moom Sinn , Addai‐Mensah Jonas , Losic Dusan 
Published: July 2012

AbstractA new approach to engineer a local drug delivery system with delayed release using nanostructured surface with nanotube arrays is presented. TNT arrays electrochemically generated on a titanium surface are used as a model substrate. Polymer micelles as drug carriers encapsulated with drug are loaded at the bottom of the TNT structure and their delayed release is obtained by loading blank micelles (without drug) on the top. The delayed and time‐controlled drug release is successfully demonstrated by controlling the ratio of blank and drug loaded‐micelles. The concept is verified using four different polymer micelles (regular and inverted) loaded with water‐insoluble (indomethacin) and water‐soluble drugs (gentamicin).magnified image
Methylated actinomycin D, a novel actinomycin D analog induces apoptosis in HepG2 cells through Fas‐ and mitochondria‐mediated pathways
Authors: Chen Yongqiang , Liu Jinjuan , Yuan Bo , Cao Chengliang , Qin Sheng , Cao Xiaoying , Bian Guangkai , Wang Zhe , Jiang Jihong 
Published: July 2012

AbstractActinomycin D (Act D), a well known of clinical antitumor drug, has been used for the treatment of some highly malignant tumors, however, the clinical application was limited by its extreme cytotoxicity. In the present study, we reported that methylated actinomycin D (mAct D), a novel actinomycin D analog isolated from Streptomyces sp. KLBMP 2541 in our previous study, could not only exert stronger inhibitory effects on several human cancer cells than Act D in dose‐ and time‐dependent manner at ng concentrations, especially on HepG2 cells, but also lower cytotoxicity in normal cells (HL‐7702). Base on these results, HepG2 cells were treated for further study to illustrate the potential mechanism of mAct D. The results of nuclei morphology examination, DNA fragmentation detection, sub‐G1 analysis, annexin V‐FITC/PI staining and activation of caspase‐3 indicated mAct D significantly induced HepG2 cells apoptosis. Semiquantitative RT‐PCR and Western blot analysis revealed that mAct D induced apoptosis in HepG2 cells through mitochondria‐dependent pathway by increasing levels of caspase‐9, Bax, Bak while decreasing levels of Bcl‐2, Bid, and Fas‐dependent pathway by increasing levels of Fas, FasL, FADD, and caspase‐8. Subsequently, pretreatment with specific inhibitor of caspase‐8 Z‐LEHD‐FMK and caspase‐9 Z‐LEHD‐FMK significantly attenuated caspase‐3 activity, the cleavage of caspase‐3 and PARP, meanwhile increased the cell viability. In addition, p53 and mitochondrial transcription factor A (mtTFA) were also upregulated. Taken together, ng concentrations mAct D induces the apoptosis of HepG2 through Fas‐ and mitochondria‐mediated pathway and presents a potential novel alternative agent for the treatment of human hepatic carcinoma. © 2012 Wiley Periodicals, Inc.
High‐resolution functional MRI at 3 T: 3D/2D echo‐planar imaging with optimized physiological noise correction
Authors: Lutti Antoine , Thomas David L. , Hutton Chloe , Weiskopf Nikolaus 
Published: July 2012

AbstractHigh‐resolution functional MRI (fMRI) offers unique possibilities for studying human functional neuroanatomy. Although high‐resolution fMRI has proven its potential at 7 T, most fMRI studies are still performed at rather low spatial resolution at 3 T. We optimized and compared single‐shot two‐dimensional echo‐planar imaging (EPI) and multishot three‐dimensional EPI high‐resolution fMRI protocols. We extended image‐based physiological noise correction from two‐dimensional EPI to multishot three‐dimensional EPI. The functional sensitivity of both acquisition schemes was assessed in a visual fMRI experiment. The physiological noise correction increased the sensitivity significantly, can be easily applied, and requires simple recordings of pulse and respiration only. The combination of three‐dimensional EPI with physiological noise correction provides exceptional sensitivity for 1.5 mm high‐resolution fMRI at 3 T, increasing the temporal signal‐to‐noise ratio by more than 25% compared to two‐dimensional EPI. Magn Reson Med, 2013. © 2012 The Authors. Magnetic Resonance in Medicine Published by Wiley Periodicals, Inc. on behalf of International Society of Medicine in Resonance.
Automated algorithm for reconstruction of the complete spine from multistation 7T MR data
Authors: Dzyubachyk Oleh , Lelieveldt Boudewijn P. F. , Blaas Jorik , Reijnierse Monique , Webb Andrew , van der Geest Rob J. 
Published: July 2012

AbstractRecent technical developments in high‐field MRI have enabled high‐resolution imaging of the whole spine within clinically acceptable times. However, analysis of such data requires intensity inhomogeneity correction and volume stitching, both of which are typically performed manually. In this work, an automated method for reconstruction of the complete spine from multistation 7T MR data is presented. The method consists of a number of image processing steps, in particular intensity inhomogeneity correction and image registration for recovery of unknown interscan bed translations, which result in high‐quality spine volume reconstructions. The registration performance of the developed algorithm was validated on 18 datasets acquired in two or three stations. In all the test cases, our algorithm was able to produce correct reconstruction of the spine volume. The resulting mean registration error (0.53 mm) is found to be lower than the pixel size, demonstrating robustness and accuracy of the proposed method. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Synergistic regulation of p53 by Mdm2 and Mdm4 is critical in cardiac endocardial cushion morphogenesis during heart development
Authors: Zhang Qin , He Xueyan , Chen Lai , Zhang Chenxi , Gao Xiang , Yang Zhongzhou , Liu Geng 
Published: July 2012

AbstractCongenital heart defects (CHDs) are the most prevalent human birth defects. More than 85% of CHDs are thought to result from a combination of genetic susceptibilities and environmental stress. However, the stress‐related signalling pathways involved remain largely unknown. The p53 transcription factor is a key tumour suppressor and a central regulator of the cellular stress responses. p53 activities are tightly regulated by its inhibitors Mdm2 and Mdm4 at the post‐translational level. Here we used the Cre–loxP system to delete Mdm2 (Tie2Cre;Mdm2FM/FM) or one copy of both Mdm2 and Mdm4 (Tie2Cre;Mdm2FM/+; Mdm4+/−) in endothelial/endocardial cells and their derivatives in mice to examine the regulation of the p53/Mdm2–Mdm4 pathway during vascular and cardiovascular development. The Tie2Cre;Mdm2FM/FM mice died before embryonic day 10.5 (E10.5) and displayed severe vascular defects. On the other hand, the Tie2Cre;Mdm2FM/+; Mdm4+/− mice displayed atrial and ventricular septal defects (ASD, VSD) of the heart, leading to severe heart dysfunction and postnatal death. During cardiac endocardial cushion morphogenesis, p53 activation was associated with defects in both the epithelial‐mesenchymal transition (EMT) of the endocardial cells and the post‐EMT proliferation of the mesenchymal cells, and the valvuloseptal phenotypes of the Tie2Cre;Mdm2FM/+; Mdm4+/− mice were fully rescued by deletion of one copy of p53. Strikingly, maternal exposure to low‐dose X‐rays in C57BL/6 mice mimicked the congenital heart malformations seen in the Tie2Cre;Mdm2FM/+; Mdm4+/− model, which was also dependent on p53 status, establishing a link between maternal exposures and CHD susceptibility through the p53 pathway. These data revealed a new regulatory mechanism in cardiac endocardial cushion morphogenesis and suggested a possible cause of CHDs due to environmental stress. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.