bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bromenium‐Catalysed Tandem Ring Opening/Cyclisation of Vinylcyclopropanes and Vinylcyclobutanes: A Metal‐Free [3+2+1]/[4+2+1] Cascade for the Synthesis of Chiral Amidines and Computational Investigation
Authors: Ganesh Venkataraman , Sureshkumar Devarajulu , Chanda Debasree , Chandrasekaran Srinivasan 
Published: September 2012

AbstractWe present a detailed study of a [3+2+1] cascade cyclisation of vinylcyclopropanes (VCP) catalysed by a bromenium species (Brδ+Xδ−) generated in situ, which results in the synthesis of chiral bicyclic amidines in a tandem one‐pot operation. The formation of amidines involves the ring‐opening of VCPs with BrX, followed by a Ritter‐type reaction with chloramine‐T and a tandem cyclisation. The reaction has been further extended to vinylcyclobutane systems and involves a [4+2+1] cascade cyclisation with the same reagents. The versatility of the methodology has been demonstrated by careful choice of VCPs and VCBs to yield bicyclo[4.3.0]‐, ‐[4.3.1]‐ and ‐[4.4.0]amidines in enantiomerically pure form. On the basis of the experimental observations and DFT calculations, a reasonable mechanism has been put forth to account for the formation of the products and the observed stereoselectivity. We propose the existence of a π‐stabilised homoallylic carbocation at the cyclopropane carbon as the reason for high stereoselectivity. DFT studies at B3LYP/6‐311+G** and M06‐2X/6‐31+G* levels of theory in gas‐phase calculations suggest the ring‐opening of VCP is initiated at the π‐complex stage (between the double bond and BrX). This can be clearly perceived from the solution‐phase (acetonitrile) calculations using the polarisable continuum model (PCM) solvation model, from which the extent of the ring opening of VCP was found to be noticeably high. Studies also show that the formation of zero‐bridge bicyclic amidines is favoured over other bridged bicyclic amidines. The energetics of competing reaction pathways is compared to explain the product selectivity.
Comparitive study on facilitated pertraction of succinic acid using TRI‐n‐octylamine without and with 1‐octanol
Authors: Caşcaval Dan , Poştaru Madalina , Galaction Anca‐Irina , Kloetzer Lenuta 
Published: September 2012

AbstractSuccinic acid has been pertracted with TOA using free liquid membranes without or with 1‐octanol. The addition of the alcohol led to the increase of up to 2.8–3 times of the acid's initial and final mass flows. At the same time, the influence of 1‐octanol on the transport capacity of the pertraction system was negative, its addition inducing the accumulation of succinic acid into the liquid membrane. A mathematical model describing the acid accumulation inside the liquid membrane has been developed for pertraction systems without and with 1‐octanol and offers good concordance with the experimental data. © 2012 Canadian Society for Chemical Engineering
Effect of annealing on the properties of chemical bath deposited nanorods of CdSe thin films
Authors: Bakiyaraj G. , Dhanasekaran R. 
Published: September 2012

AbstractCadmium selenide (CdSe) thin films have been deposited by chemical bath deposition (CBD) on a glass substrate and they are annealed at 450 °C for 1 h. Scanning electron microscopic (SEM) image of as‐deposited CdSe shows the spherical shaped grains distributed over entire glass substrate. When it is annealed at 450 °C, clusters of nano‐rods with star shaped grains are formed. The X‐ray diffraction (XRD) study of the as‐deposited films exhibits a polycrystalline nature and it undergoes a structural phase transition from the metastable cubic to the stable hexagonal phase when annealed at 450 °C. Optical band gap of as‐deposited films (2.0 eV) has a blue shift with respect to the bulk value (1.7 eV) due to quantum confinement. The band gap energies of the films are decreased from 2.0 eV to 1.9 eV due to annealing at the temperature of 450 °C. The electrical resistivity, Hall mobility and carrier concentration of as‐deposited and annealed films are determined.
Handedness in infants' tool use
Authors: Rat‐Fischer Lauriane , O'Regan J. Kevin , Fagard Jacqueline 
Published: September 2012

AbstractIn this study, we investigated whether hand preference influences infants' choice of what hand to use in grasping a new tool presented at the midline, and whether this will change in the course of learning the functionality of a tool. The tool was a rake within reach placed beside an out‐of‐reach toy presented either to its right or to its left. Forty‐eight infants from 16 to 22 months of age were tested. The results show that use of the right‐preferred hand to grasp the rake is strong as of 16 months of age and does not change significantly with age in the condition where using the right hand leads to a better outcome than using the left hand. In the condition where using the left‐non‐preferred hand makes toy retrieval easier, infants increasingly use the left hand with age. Thus, when grasping the tool, younger infants are more influenced by their hand preference than older infants, who are better at anticipating the most successful strategies. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 860–868, 2013.
Transcriptional networks that mediate signals from reproductive tissues to influence lifespan
Authors: Ghazi Arjumand 
Published: September 2012

AbstractAging and reproduction are two defining features of our life. Historically, research has focused on the well‐documented decline in reproductive capacity that accompanies old age, especially with increasing maternal age in humans. However, recent experiments in model organisms such as worms, flies, and mice have shown that a dialogue in the opposite direction may be widely prevalent, and that signals from reproductive tissues have a significant effect on the rate of aging of organisms. This pathway has been described in considerable detail in the nematode Caenorhabditis elegans. Molecular genetic studies suggest that signals from the germline control a network of transcriptional regulators that function in the intestine to influence longevity. This network includes conserved, longevity‐promoting Forkhead Box (FOX) family transcription factors such as DAF‐16/FOXO and PHA‐4/FOXA, nuclear hormone receptors, as well as a transcription elongation factor, TCER‐1/TCERG1. Genomic and targeted molecular analyses have revealed that these transcription factors modulate autophagy, lipid metabolism, and possibly other cellular processes to increase the length of the animal's life. This review aims to provide an overview of the current knowledge on the genetic mechanism that underlies the reproductive control of aging with particular focus on the transcriptional regulators that constitute the main molecular players in this longevity pathway. genesis
51:1‐15, 2013. © 2012 Wiley Periodicals, Inc
Aberrant methylation of the PTCH1 gene promoter region in aberrant crypt foci
Authors: Peng Liang , Hu Jingjing , Li Shujun , Wang Zhongqiu , Xia Bingqing , Jiang Bo , Li Bingsheng , Zhang Yu , Wang Jing , Wang Xinying 
Published: September 2012

AbstractPatched homolog 1 (PTCH1) is a known tumor suppressor that regulates the Hedgehog (Hh) pathway and has been implicated in tumorigenesis. The role of PTCH1 in colon carcinogenesis, however, is controversial. The aim of the present study was to investigate epigenetic modifications of PTCH1 in aberrant crypt foci (ACF), the earliest precursor lesion of colorectal cancer (CRC). Using laser‐capture microdissection (LCM), a pure population of ACF epithelial cells was isolated and studied. The inherent protein expression levels of SHH, PTCH1, SMO and GLI1 were assessed by immunohistochemistry for 405 ACF, including 54 dysplastic ACF (d‐ACF) and 351 non‐dysplastic ACF (n‐ACF). The mRNA levels and methylation status of PTCH1 were also determined in 54 d‐ACF and 96 n‐ACF. Our data showed that the expression of SHH, SMO and GLI1 was significantly up‐regulated in d‐ACF, compared to n‐ACF. Also, the mRNA and protein levels of PTCH1 were lower in d‐ACF than n‐ACF. Using MSP or MS‐HRM, PTCH1 methylation was present in 64.8% (35/54) or 63.3% (34/54), respectively, of d‐ACF and 19.8% (19/96) or 22.9% (11/48), respectively, of n‐ACF. PTCH1 methylation was more frequent in d‐ACF than n‐ACF (p < 0.001) and was associated with PTCH1 mRNA levels (r = 0.358, p < 0.01). There was a statistically significant correlation between PTCH1 methylation status and the prevalence of colorectal neoplasms. In conclusion, this study suggests that aberrant methylation of the PTCH1 promoter may be an early, initiating event of colon carcinogenesis.
Drug Dosing Based on Weight and Body Surface Area: Mathematical Assumptions and Limitations in Obese Adults
Authors: Pai Manjunath P. 
Published: September 2012

The average weight of adults in the United States has increased by 25 pounds (11 kg) over the past 50 years, with a marginal change in height. Drugs are generally dosed according to one of three approaches: fixed dosing, weight‐based dosing, or body surface area–based dosing. Dosing based on body weight or body surface area assumes that drug pharmacokinetic parameters increase in proportion with increasing body size. In contrast, dosing drugs on a fixed basis assumes that drug pharmacokinetic parameters do not increase with body size. Unfortunately, early stages of clinical drug development tend to include adults within a narrow range of body size. This study population does not reflect the current U.S. population distribution and does not permit evaluation of the correct relationship between body size and drug clearance. As a consequence, a weight‐based or body surface area–based dosing regimen defined during drug development may not be applicable to U.S. patient populations. These dosing strategies are more likely to result in drug overexposure (weight‐based approach) or underexposure (body surface area–based approach) among obese patients. Alternate weight descriptors such as ideal body weight, adjusted body weight, fat‐free weight, and lean body weight are used to prevent drug overexposure with weight‐based dosing, but their benefits and limitations must be understood. Reappraisal of the drug dosing paradigm is needed in this era of rising obesity; however, until drug‐specific reviews can be performed, clinical studies must include patients at the extremes of the weight continuum to ensure applicable dose extrapolation for body size.
Effect of Therapeutic Doses of Acetaminophen (up to 4 g/day) on Serum Alanine Aminotransferase Levels in Subjects Consuming Ethanol: Systematic Review and Meta‐analysis of Randomized Controlled Trials
Authors: Rumack Barry , Heard Kennon , Green Jody , Albert Donald , Bucher‐Bartelson Becki , Bodmer Michael , Sivilotti Marco L. A. , Dart Richard C. 
Published: September 2012

Study ObjectiveTo quantify the effect of therapeutic doses of acetaminophen on serum alanine aminotransferase (ALT) levels in subjects who consumed ethanol.DesignSystematic review of six randomized placebo‐controlled trials, of which five were included in a meta‐analysis.SubjectsSubjects included in the meta‐analysis were those who consumed ethanol and received acetaminophen in doses up to 4 g/day (551 subjects) or placebo (350 subjects).Measurements and Main ResultsA comprehensive literature search of the MEDLINE, EMBASE, and International Pharmaceutical Abstracts databases and the Cochrane Central Register of Controlled Trials was performed to identify randomized, placebo‐controlled trials that enrolled subjects who consumed ethanol, received acetaminophen in therapeutic doses up to 4 g/day, and had serum ALT level measurements. A total of 184 articles were identified; six articles met all criteria. Five of the six articles reported ALT levels on study day 4 for both groups of subjects who received acetaminophen or placebo. Thus, for the meta‐analysis, we used the primary outcome of mean change in serum ALT level from baseline to day 4 in the acetaminophen groups compared with the placebo groups. We found that the difference in mean change from baseline ALT levels between the acetaminophen and placebo groups on day 4 was 0.0 U/L (95% confidence interval −0.2–0.1 U/L). There were no reports of liver dysfunction, liver failure, or death in any of the trials.ConclusionIn randomized, placebo‐controlled trials of subjects who consumed ethanol, no elevation of ALT level on study day 4 was noted when subjects ingested up to 4 g/day of acetaminophen.
Effects of transmyocardial jet revascularization with chitosan hydrogel on channel patency and angiogenesis in canine infarcted hearts
Authors: Zhou Dayan , Xiong Lu , Wu Qi , Guo Rui , Zhou Zhiyi , Zhu Que , Jiang Yonghong , Huang Jing 
Published: September 2012

AbstractThe purpose of this study was to investigate whether transmyocardial jet revascularization (TMJR) with chitosan scaffolds retains channel patency and enhances angiogenesis after acute myocardial infarction (AMI) in a canine model. A total of 32 canines were randomly divided into four groups: myocardial infarction (MI), normal saline (NS), chitosan hydrogel (CH), and chitosan plus growth factor (CH + GF) groups. TMJR was performed surgically using a needle‐free injector from the epicardium of canines in the NS, CH, and CH + GF groups; channels were filled with NS, CH, and CH + GF, respectively. After 6 weeks, the patency of the channels and angiogenesis around the channels were assessed by hematoxylin–eosin staining, immunohistochemistry, and Masson's trichrome staining. Results suggest that the channels in the CH and CH + GF groups may retain patency with luminal endothelization. Moreover, the vessel densities of the NS, CH, and CH + GF groups were significantly higher than that of the MI group, and that of the CH + GF group was the highest (p < 0.05). This study suggests that TMJR with chitosan scaffolds may help retain transmyocardial channel patency and enhance angiogenesis after AMI in canines. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Aptamers: A promising tool for cancer imaging, diagnosis, and therapy
Authors: Liu KuanCan , Lin BaoShun , Lan XiaoPeng 
Published: September 2012

AbstractAptamers are a group of molecules, which can specifically bind, track, and inhibit target molecules, comprising DNA aptamers, RNA aptamers, and peptide aptamers. So far, there are much progress about developing novel aptamers and their expansile applications. This prospect systematically introduces the composition and technological evolution of aptamers, and then focuses on the application of aptamers in cancer diagnosis, imaging, and therapy. Following this, we discuss the potential to harness aptamers in discovering the biomarker of stem cells, which is favorable for us to study the normal developmental or abnormal pathological process of tissue and to deliver drugs into target cells or tissues in the future. J. Cell. Biochem. 114: 250–255, 2013. © 2012 Wiley Periodicals, Inc.
Secreted phosphoprotein‐24 kDa (Spp24) attenuates BMP‐2‐stimulated Smad 1/5 phosphorylation and alkaline phosphatase induction and was purified in a protective complex with alpha2‐Macroglobulins From Serum
Authors: Zhao Ke‐Wei , Murray Samuel S. , Murray Elsa J. Brochmann 
Published: September 2012

AbstractSecreted phosphoprotein‐24 kDa (Spp24) binds cytokines of the bone morphogenetic protein/transforming growth factor‐β (BMP/TGFβ) superfamily and is one of the most abundant serum phosphoproteins synthesized by the liver. Little is known about how Spp24 binding affects BMP signal transduction and osteoblastic differentiation or how this labile protein is transported from the liver to remote tissues, such as bone. When Spp24 was administered to W‐20‐17 mesenchymal stem cells with rhBMP‐2, short‐term Smad1/5 phosphorylation was inhibited, intermediate‐term alkaline phosphatase (ALP) induction was blunted, and long‐term mineralization was unaffected. This supports the hypothesis that Spp24 proteolysis restricts the duration of its regulatory effects, but offers no insight into how Spp24 is transported intact from the liver to bone. When Spp24 was immunopurified from serum and subjected to native PAGE and Western blotting, a high molecular weight band of >500 kDa was found. Under reducing SDS–PAGE, a 24 kDa band corresponding to monomeric Spp24 was liberated, suggesting that Spp24 is bound to a complex linked by disulfide bonds. However, such a complex cannot be disrupted by 60 mM EDTA under non‐reducing condition or in purification buffers containing 600 mM NaCl and 0.1% Tween‐20 at pH 2.7–8.5. LC–MS/MS analysis of affinity‐purified, non‐reducing SDS–PAGE separated, and trypsin digested bands showed that the Spp24 was present in a complex with three α2‐macroglobulins (α2‐macroglobulin [α2M], pregnancy zone protein [PZP] and complement C3 [C3]), as well as ceruloplasmin and the protease inhibitor anti‐thrombin III (Serpin C1), which may protect Spp24 from proteolysis. J. Cell. Biochem. 114: 378–387, 2013. © 2012 Wiley Periodicals, Inc.
Mesenchymal stem cells protect cigarette smoke‐damaged lung and pulmonary function partly via VEGF–VEGF receptors
Authors: Guan Xiao‐Jun , Song Lin , Han Feng‐Feng , Cui Zhi‐Lei , Chen Xi , Guo Xue‐Jun , Xu Wei‐Guo 
Published: September 2012

AbstractProgressive pulmonary inflammation and emphysema have been implicated in the progression of chronic obstructive pulmonary disease (COPD), while current pharmacological treatments are not effective. Transplantation of bone marrow mesenchymal stem cells (MSCs) has been identified as one such possible strategy for treatment of lung diseases including acute lung injury (ALI) and pulmonary fibrosis. However, their role in COPD still requires further investigation. The aim of this study is to test the effect of administration of rat MSCs (rMSCs) on emphysema and pulmonary function. To accomplish this study, the rats were exposed to cigarette smoke (CS) for 11 weeks, followed by administration of rMSCs into the lungs. Here we show that rMSCs infusion mediates a down‐regulation of pro‐inflammatory mediators (TNF‐α, IL‐1β, MCP‐1, and IL‐6) and proteases (MMP9 and MMP12) in lung, an up‐regulation of vascular endothelial growth factor (VEGF), VEGF receptor 2, and transforming growth factor (TGFβ‐1), while reducing pulmonary cell apoptosis. More importantly, rMSCs administration improves emphysema and destructive pulmonary function induced by CS exposure. In vitro co‐culture system study of human umbilical endothelial vein cells (EA.hy926) and human MSCs (hMSCs) provides the evidence that hMSCs mediates an anti‐apoptosis effect, which partly depends on an up‐regulation of VEGF. These findings suggest that MSCs have a therapeutic potential in emphysematous rats by suppressing the inflammatory response, excessive protease expression, and cell apoptosis, as well as up‐regulating VEGF, VEGF receptor 2, and TGFβ‐1. J. Cell. Biochem. 114: 323–335, 2013. © 2012 Wiley Periodicals, Inc.
Abnormality of maternal‐to‐embryonic transition contributes to MEHP‐induced mouse 2‐cell block
Authors: Chu Da‐Peng , Tian Shi , Qi Lu , Hao Chan‐Juan , Xia Hong‐Fei , Ma Xu 
Published: September 2012

AbstractMono (2‐ethylhexyl) phthalate (MEHP), an environmental contaminant, is known to cause many serious diseases, especially in reproductive system. However, little is known about the effect of MEHP on preimplantation embryo development. In this study, we found that the development of mouse 2‐cell embryo was blocked by 10−3 M MEHP. A significant increase in the level of reactive oxygen species (ROS) was observed in arrested 2‐cell embryo following 10−3 M MEHP treatment for 24 h. However, antioxidants, catalase (CAT), and superoxide dismutase (SOD), reduced intracellular ROS and protected MEHP‐exposed embryos from death but failed to return the arrested embryos. Further experiments demonstrated that the level of apoptosis was not altered in live arrested 2‐cell embryo and increased in dead arrested 2‐cell embryo after MEHP treatment, which implied that ROS and apoptosis were not related with 2‐cell block. During analysis of the indicators of embryonic genome activation (EGA) initiation (Hsc70, MuERV‐L, Hsp70.1, eIF‐1A, and Zscan4) and maternal‐effect genes (OCT4 and SOX2), we found that MEHP treatment could significantly decline Hsc70, MuERV‐L mRNA level and SOX2 protein level, and markedly enhance Hsp70.1, eIF‐1A, Zscan4 mRNA level, and OCT4 protein level at 2‐cell to 4‐cell stage. Supplementation of CAT and SOD did not reverse the expression tendency of EGA related genes. Collectively, this study demonstrates for the first time that MEHP‐induced 2‐cell block is mediated by the failure of EGA onset and maternal‐effect genes, not oxidative stress and apoptosis. J. Cell. Physiol. 228: 753–763, 2013. © 2012 Wiley Periodicals, Inc.
Human mesenchymal stem cells: A bank perspective on the isolation, characterization and potential of alternative sources for the regeneration of musculoskeletal tissues
Authors: Moroni Lorenzo , Fornasari Pier Maria 
Published: September 2012

AbstractThe continuous discovery of human mesenchymal stem cells (hMSCs) in different tissues is stirring up a tremendous interest as a cell source for regenerative medicine therapies. Historically, hMSCs have been always considered a sub‐population of mononuclear cells present in the bone marrow (BM). Although BM‐hMSCs are still nowadays considered as the most promising mesenchymal stem cell population to reach the clinics due to their capacity to differentiate into multiple tissues, hMSCs derived from other adult and fetal tissues have also demonstrated to possess similar differentiation capacities. Furthermore, different reports have highlighted a higher recurrence of hMSCs in some of these tissues as compared to BM. This offer a fascinating panorama for cell banking, since the creation of a stem cell factory could be envisioned where hMSCs are stocked and used for ad hoc clinical applications. In this review, we summarize the main findings and state of the art in hMSCs isolation, characterization, and differentiation from alternative tissue sources and we attempt to compare their potency for musculoskeletal regeneration. J. Cell. Physiol. 228: 680–687, 2013. © 2012 Wiley Periodicals, Inc.
Histogenesis of the unique morphology of proboscidean ivory
Authors: Virág Attila 
Published: September 2012

AbstractThe chequered pattern (often called Schreger pattern), which can be seen by unaided eye on transverse profiles of several proboscidean tusks and which can be emphasized by the spreading pattern of the cracks or by mineral discoloration, is an autapomorph feature of the clade Elephantoidea. The pattern differs among proboscidean taxa; therefore, it allows the coarse differentiation of elephants, mammoths, and some other basal groups. Such identification methods could facilitate efforts concerned with protection of the remaining elephant populations through ivory trade restrictions, since the tooth dentine from extinct Mammuthusprimigenius and from extant Loxodontaafricana and Elephasmaximus are the most common raw materials of the ivory carvings. The aim of this study was to show the internal structure of proboscidean ivory and to revise the existing theories on the aforementioned pattern of the elephantoids with reflections on the events which lead to the development of this microstructure. Thin sections and natural crack surfaces with various orientations of M.primigenius, Elephasantiquus, Prodeinotherium, and Deinotherium tusk fragments were used to produce a three‐dimensional model which explains the features on all profiles. The “phase shift” model is introduced, which assumes a sinusoid undulation of the dentinal tubules in radial profiles in the case of elephantoids. The model was confirmed by photomicrographs, scanning electron microscopic images, interpretation of natural crack surfaces, and radial displacement analysis of the dentinal tubules. The latter proved that the adjacent waves are not in the same phase. Several new nondestructive distinguishing methods are described here on the basis of the correlation between some microscopic and macroscopic features related to the Schreger pattern. J. Morphol. 2012. © 2012 Wiley Periodicals, Inc.