bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanism of Ketone Allylation with Allylboronates as Catalyzed by Zinc Compounds: A DFT Study
Authors: Li Weiyi , Su Zhishan , Hu Changwei 
Published: November 2012

AbstractThe mechanism of the allylation reaction between 4‐chloroacetophenone and pinacol allylboronates catalyzed by ZnEt2 with alcohols was investigated using density functional theory (DFT) at the M05‐2X/6‐311++G(d,p) level. The calculations reveal that the reaction prefers to proceed through a double γ‐addition stepwise reaction mechanism rather than a Lewis acid‐catalyzed concerted one. The intermediate with a four‐coordinated boron center, which is formed through proton transfer from EtOH to the ethyl group of ZnEt2 mediated by the boron center, is the active species and an entrance for the catalytic cycle. The latter is composed of three elementary steps: 1) boron to zinc transmetalation leading to the formation of allylzincate species, 2) electrophilic addition of ketone to allylzincate species, and 3) generation of the final product with recovery of the catalyst. The boron to zinc transmetalation step has the largest energy barrier of 61.0 kJ mol−1 and is predicted to be the rate‐determining step. The calculations indicate that the additive EtOH plays important roles both in lowering the activation free energy for the formation of the four‐coordinated boron active intermediate and in transforming the low catalytic activity ZnEt2 into high activity zinc alkoxide species. The alcohols with a less sterically encumbering R group might be the effective additives. The substituted groups on the allylboronates might primarily affect the boron to zinc transmetalation, and the allylboronates with substituents on the Cγ atom is poor in reactivity. The comparison of the catalytic effect between the zinc compounds investigated suggest that Zn(OEt)2, Zn(OH)2, and ZnF2 exhibit higher catalytic efficiency for the boron to zinc transmetalation due to the activation of the BCα bond through orbital interactions between the p orbitals of the EtO, OH, F groups and the empty p orbital of the boron center.
Single threshold optimization and a novel double threshold scheme for non‐line‐of‐sight identification
Authors: Wu Shixun , Li Jiping , Liu Shouyin 
Published: November 2012

SUMMARYNon‐line‐of‐sight (NLOS) identification is a critical issue in wireless location system. The traditional method only considers the probability of false alarm to obtain the single threshold to identify the wireless propagation environment as line of sight (LOS) or NLOS. However, the probability of missed detection is rarely discussed. In this paper, firstly, the optimal single threshold is derived through minimizing the total error probability, which is the sum of the probability of false alarm and the probability of missed detection. Further, if the prior probabilities for the LOS and NLOS environment are available, a novel double threshold method based on the optimal single threshold is proposed to perform NLOS identification. By comparing the total error probability, we show through simulation results that the performance of the optimal single threshold is better than that of the traditional single threshold. Moreover, the novel double threshold NLOS identification scheme is feasible and better than the optimal single threshold scheme. It is also shown that the analytical results are consistent with the simulated ones.Copyright © 2012 John Wiley & Sons, Ltd.
Effects of inbreeding on mouthpart deformities of Chironomus riparius under sublethal pesticide exposure
Authors: Vogt Christian , Langer-Jaesrich Miriam , Elsässer Oliver , Schmitt Claudia , Van Dongen Stefan , Köhler Heinz-R. , Oehlmann Jörg , Nowak Carsten 
Published: November 2012

Abstract
Mouthpart deformities in chironomids have been reported to indicate adverse effects of environmental pollutants. The authors assessed rates of mouthpart deformities in tributyltin-exposed, inbred, and outcrossed Chironomus riparius larvae over multiple generations. The authors found that the occurrence of mouthpart deformities was significantly correlated with inbreeding, whereas no correlation was found with the tributyltin exposure. The present study confirms the strong effect of high inbreeding rates on developmental deformities in chironomids. Environ. Toxicol. Chem. 2013;32:423–425. © 2012 SETAC
Prognostic significance of disease‐free interval in head and neck cutaneous squamous cell carcinoma with nodal metastases
Authors: Ebrahimi Ardalan , Clark Jonathan R. , Ahmadi Nazanin , Palme Carsten E. , Morgan Gary J. , Veness Michael J. 
Published: November 2012

AbstractBackgroundThe purpose of this study was to determine whether the disease‐free interval (DFI) between treatment of primary head and neck cutaneous squamous cell carcinoma (SCC) and the development of regional metastases is an independent prognostic factor.MethodsA retrospective analysis of 229 patients with metastatic nodal head and neck cutaneous SCC, treated with curative intent by surgery ± adjuvant radiotherapy was conducted.ResultsAfter adjusting for the effect of nodal staging, extracapsular spread, involved margins, adjuvant radiotherapy, and immunosuppression, a short DFI (≤9 months vs >9 months) was a significant predictor of disease‐related mortality (hazard ratio [HR], 3.0; 95% confidence interval [CI], 1.4–6.5; p = .004) and locoregional relapse (HR, 2.0; 95% CI, 1.1–4.0; p = .044).ConclusionThe DFI is a potentially powerful independent prognostic factor in patients with regional metastases secondary to head and neck cutaneous SCC. It provides information before definitive treatment that may ultimately assist clinicians in applying a risk‐adapted management paradigm. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Effects of platelet‐rich plasma‐containing fragmin/protamine microparticles in enhancing endothelial and smooth muscle cell growth and inducing collateral vessels in a rabbit model of hindlimb ischemia
Authors: Fujita Masanori , Horio Takuya , Kishimoto Satoko , Nakamura Shingo , Takikawa Megumi , Nakayama Takefumi , Yamamoto Yoritsuna , Shimizu Masafumi , Hattori Hidemi , Tachibana Shoichi , Ishihara Masayuki 
Published: November 2012

AbstractThe purpose of the study was to evaluate the effects of isogenous platelet‐rich plasma (PRP)–containing fragmin/protamine microparticles (F/P MPs) as a delivery system for proteins in PRP on growth of endothelial and smooth muscle cells (SMCs)in vitroand as an alternative treatment for peripheral arterial disease (PAD) and critical limb ischemia. Frozen and thawed PRP contains high concentrations of growth factors that are adsorbed by F/P MPs. Human aorta endothelial cells (AECs) and SMCs were grown in a medium with PRP. Addition of F/P MPs significantly enhanced the proliferative effects of PRP on AECs and SMCs at 37°C for >10 days. Intramuscular administration of phosphate‐buffered saline (PBS; 2 mL, control), F/P MPs (12 mg in 2 mL PBS), PRP (2 mL), or PRP (2 mL) containing F/P MPs (12 mg) was then performed in a rabbit model of hindlimb ischemia prepared by resection of the left femoral artery. Blood flow and pressure were measured on days 0, 14, and 28, and angiography to assess arteriogenesis was performed on day 28. PRP‐containing F/P MPs strongly induced functional collateral vessels in the rabbit model of hindlimb ischemia, indicating possible use of these microparticles in therapy for PAD. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 101B: 36–42, 2013.
Lignin extraction and purification with ionic liquids
Authors: Prado Raquel , Erdocia Xabier , Labidi Jalel 
Published: November 2012

AbstractBACKGROUNDIn new biorefineries the use of new green solvents is essential
in order to minimize the employment of volatile organic solvents.Lignin is the most abundant residue in paper industries, however, it is necessary to purify it in order to obtain revalorized products.RESULTSIn this study, soda and organosolv lignins obtained from apple
tree prunings (Malus domestica) were purified using
[Bmim][MeSO4], and the lignin extracted from raw material was tested comparing different conditions. [Bmim][MeSO4], EtmimAc(1‐Ethyl‐3‐methylimidazolium acetate) and BmimCl, were the ionic liquids chosen for the experimentation. The lignins obtained were characterized by FTIR, TGA, RMN and HPLC, in order to determinate the influence of the different treatments on their structures. Lignin of 91.2% purity was obtained directly from raw material using ionic liquids, whereas organosolv lignin purity ranges from 85.7% to 90.9%, and soda lignin from 12.9% to 89.6% after treatment with [Bmim][MeSO4].CONCLUSIONResults showed that the use of
[Bmim][MeSO4] is the best option to purify and
extract lignin from raw material. In addition, microwave radiation
enhanced the energy consumption of the process.© 2012 Society of Chemical Industry
Protein kinase cα is involved in impaired perinatal hypothyroid rat brain development
Authors: Zhang Hong‐Mei , Lin Ning , Dong Yan , Su Qing , Luo Min 
Published: November 2012

AbstractProtein kinase Cα (PKCα) has been implicated in the regulation of a variety of cellular functions, such as proliferation, differentiation, and apoptosis, in response to a diverse range of stimuli. Activated PKCα mediates oxidative stress, apoptosis, and inflammatory reaction. Thyroid hormone (TH) is essential for the proper development of the mammalian central nervous system. TH deficiency during critical periods of brain development results in permanent cognitive and neurological impairments. In the present study, we attempted to explore whether PKCα is involved in impaired brain function in developing hypothyroid rat brain. Severe perinatal hypothyroidism was obtained by administration of 30 mg/day propylthiouracil to dams. Brain PKC activity in hypothyroid pups was increased significantly in cytosol and membrane fractions. The change of membrane PKC activity was more marked than that of cytosol, and hypothyroidism led to a higher ratio of membrane PKC activity to that in cytosol, which means abnormal activation of PKC in developing hypothyroid rat brain. Thyroxine replacement partially corrected these changes. After being treated with bisindolmaleimide XI, a mainly selective inhibitor for PKCα, the hypothyroid pups showed improved place navigation test results, and further Western blot analysis showed that PKCα expression in cytosol fractions was increased in hypothyroid rat brain with or without bisindolmaleimide XI treatment, but, after treatment with bisindolmaleimide XI, PKCα content in membrane fractions decreased almost to normal. Therefore, we conclude that PKCα appears to be involved in the impaired brain development observed in perinatal hypothyroid rat brain. © 2012 Wiley Periodicals, Inc.
Pre‐ and postischemic pulsed acoustic cellular expression conditioning modulates expression of inflammation factors in cremaster ischemia/reperfusion injury model
Authors: Cwykiel Joanna M. , Klimczak Aleksandra , Krokowicz Lukasz , Siemionow Maria 
Published: November 2012

AbstractPulsed acoustic cellular expression (PACE) is a treatment that applies focused acoustic shock waves to promote tissue healing. The aim of this study was to assess the effect of PACE treatment on inflammatory responses in a cremaster muscle ischemia/reperfusion injury model. Seventeen cremaster muscle flaps were evaluated in four groups: nonischemic controls (n = 5), 5‐hour ischemia controls (n = 4), preischemic (5‐hour) PACE conditioning (n = 4), and postischemic (5‐hour) PACE conditioning (n = 4). The expression of proinflammatory cytokines (TNFα, IL‐6, IL‐1α, IL‐1β, GM‐CSF) and chemokines (CCL3, CCL4, CXCL4) was assessed using TaqMan® real‐time PCR. Expression of ELAM‐1, VCAM‐1, and ICAM‐1 was assessed by immunostaining. Preischemic PACE conditioning upregulated expression of IL‐6, CCL3, CCL4, and CXCL4, and downregulated expression of TNFα, GM‐CSF, and IL‐1α. Postischemic PACE conditioning significantly decreased expression of all evaluated genes. Pre‐ and postischemic PACE conditioning decreased expression of ELAM‐1 and ICAM‐1. Results of the study indicate that application of PACE conditioning may have a beneficial effect on the recovery of tissues subjected to the ischemia/reperfusion injury. Postischemic PACE conditioning revealed anti‐inflammatory effect as confirmed by decreased expression of inflammatory cytokines, chemokines, and cell adhesion molecules (ELAM‐1 and ICAM‐1) that are responsible for leukocyte recruitment into ischemic tissues. Hence, PACE therapy may be used effectively in clinical practice as a convenient therapeutic strategy to protect tissues against ischemia/reperfusion related injury after microsurgical procedures of free tissue transfers. © 2012 Wiley Periodicals, Inc. Microsurgery, 2013.
Microvascular changes following four‐hour single arteriole occlusion
Authors: Saltzman Darin J. , Kerger Heinz , Jimenez Juan Carlos , Farzan Dina , Wilson James M. , THOMPSON Jesse E. , Intaglietta Marcos 
Published: November 2012

AbstractBackground:Free tissue transplantations are lengthy procedures that result in prolong tissue ischemia. Restoral of blood flow is essential for free flap recovery; however, upon reperfusion tissue that is viable may continue to be nonperfused. To further elucidate this pathophysiology skeletal muscle microcirculation was investigated during reperfusion following 4‐hour single arteriole occlusion.Materials and methods:A blunt micropipette probe was use to compress a single arteriole in the unanesthetized hamster (N = 20) dorsal skinfold chamber. Arteriole (n = 20), capillary (n = 97), and postcapillary venule (n = 16) diameters and blood flow were analyzed at 0, 30, 60, 120, 240 min and 24 hours of reperfusion after 4 hour occlusion. Results: Feeding arcade arterioles exhibited a brief (<10 min) vasoconstriction [0.31 ± 0.26 (mean ± SE) of baseline] upon reperfusion followed by a maximum vasodilation at 120 min (1.3 ± 0.10: P < 0.05). Vasodilation was observed in transverse arterioles (A3) (1.8 ± 0.20: P < 0.05). Correspondingly, all arteriole and venule flow was increased by 120 min (P < 0.05) of reperfusion. There was a transient decrease in the number of flowing capillaries at 0 and 30 min reperfusion (0.73 ± 0.09 and 0.84 ± 0.06: P < 0.05, respectively).Conclusions:At the onset of reperfusion heterogeneous arteriole flow and transient decrease in flowing capillaries was observed; however, return of flow in all capillaries and an eventual hyperemic response in all arterioles suggests the reversible nature of this response. Single arteriole occlusion may allow for a more controlled and detailed microcirculatory analysis during ischemia‐reperfusion. © 2012 Wiley Periodicals, Inc. Microsurgery, 2013.
National trends in incidence rates of hospitalization for stroke in children with sickle cell disease
Authors: McCavit Timothy L. , Xuan Lei , Zhang Song , Flores Glenn , Quinn Charles T. 
Published: November 2012

AbstractBackgroundThe success of primary stroke prevention for children with sickle cell disease (SCD) throughout the United States is unknown. Therefore, we aimed to generate national incidence rates of hospitalization for stroke in children with sickle cell disease (SCD) before and after publication of the Stroke Prevention Trial in Sickle Cell Anemia (STOP trial) in 1998.ProcedureWe performed a retrospective trend analysis of the 1993–2009 Nationwide Inpatient Sample and Kids' Inpatient Databases. Hospitalizations for SCD patients 0–18 years old with stroke were identified by ICD‐9CM code. The primary outcome, the trend in annual incidence rate of hospitalization for stroke in children with SCD, was analyzed by linear regression. Incidence rates of hospitalization for stroke before and after 1998 were compared by the Wilcoxon rank‐sum test.ResultsFrom 1993 to 2009, 2,024 hospitalizations were identified for stroke. Using the mean annual incidence rate of hospitalization for stroke from 1993 to 1998 as the baseline, the rate decreased from 1993 to 2009 (point estimate = −0.022/100 patient years [95% CI, −0.039, −0.005], P = 0.027). The mean annual incidence rate of hospitalization stroke decreased by 45% from 0.51 per 100 patient years in 1993–1998 to 0.28 per 100 patient years in 1999–2009 (P = 0.008). Total hospital days and charges attributed to stroke also decreased by 45% and 24%, respectively.ConclusionsAfter publication of the STOP trial and hydroxyurea licensure in 1998, the incidence of hospitalization for stroke in children with SCD decreased across the United States, suggesting that primary stroke prevention has been effective nationwide, but opportunity for improvement remains. Pediatr Blood Cancer 2013; 60: 823–827. © 2012 Wiley Periodicals, Inc.
Fatigue response and constitutive behavior modeling of poly(ethylene terephthalate) unreinforced and nanocomposite fibers using genetic neural networks
Authors: Averett Rodney D. , Realff Mary L. , Jacob Karl 
Published: November 2012

AbstractThe constitutive behavior of poly(ethylene terephthalate) (PET) unreinforced (control) and PET fibers reinforced with 5 wt% vapor‐grown carbon nanofibers (VGCNFs) under uniaxial tension and subsequent to fatigue loading has been evaluated utilizing various analytical models. Two types of fatigue tests were performed: (1) Long cycle fatigue at 50 Hz (glassy fatigue) to evaluate fatigue resistance and (2) fatigue at 5 Hz (rubbery fatigue) to evaluate residual strength performance. The long cycle fatigue results at 50 Hz indicated that the PET‐VGCNF sample exhibited an increased fatigue resistance of almost two orders of magnitude when compared to the PET unreinforced filament. The results of the fatigue tests at 5 Hz indicated that the constitutive response of both the PET control and PET‐VGCNF samples changed subsequent to fatigue loading. The large deformation uniaxial constitutive response of the PET and PET‐VGCNF fibers was modeled utilizing genetic‐algorithm (GA) based training neural networks. The results showed that the large deformation uniaxial tension constitutive behavior of both PET unreinforced and PET‐VGCNF samples with and without prior fatigue can be represented with good accuracy utilizing neural networks trained via genetic‐based backpropagation algorithms, once the appropriate post‐fatigue constitutive behavior is utilized. Experimental data of uniaxial tensile tests and experimental postfatigue constitutive data have been implemented into the networks for adequate training. The fatigue tests were conducted under tension‐tension fatigue conditions with variations in the stress ratio (R), maximum stress (σmax), number of cycles (N), and the residual creep strain (εR). POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Cannabinoid receptor agonists upregulate and enhance serotonin 2A (5‐HT2A) receptor activity via ERK1/2 signaling
Authors: Franklin Jade M. , Carrasco Gonzalo A. 
Published: November 2012

AbstractRecent behavioral studies suggest that nonselective agonists of cannabinoid receptors may regulate serotonin 2A (5‐HT2A) receptor neurotransmission. Two cannabinoids receptors are found in brain, CB1 and CB2 receptors, but the molecular mechanism by which cannabinoid receptors would regulate 5‐HT2A receptor neurotransmission remains unknown. Interestingly, we have recently found that certain cannabinoid receptor agonists can specifically upregulate 5‐HT2A receptors. Here, we present experimental evidence that rats treated with a nonselective cannabinoid receptor agonist (CP 55,940, 50 µg/kg, 7 days) showed increases in 5‐HT2A receptor protein levels, 5‐HT2A receptor mRNA levels, and 5‐HT2A receptor‐mediated phospholipase C beta (PLCβ) activity in prefrontal cortex (PFCx). Similar effects were found in neuronal cultured cells treated with CP 55,940 but these effects were prevented by selective CB2, but not selective CB1, receptor antagonists. CB2 receptors couple to the extracellular kinase (ERK) signaling pathway by Gαi/o class of G‐proteins. Noteworthy, GP 1a (selective CB2 receptor agonist) produced a strong upregulation of 5‐HT2A receptor mRNA and protein, an effect that was prevented by selective CB2 receptor antagonists and by an ERK1/2 inhibitor, PD 198306. In summary, our results identified a strong cannabinoid‐induced upregulation of 5‐HT2A receptor signaling in rat PFCx. Our cultured cell studies suggest that selective CB2 receptor agonists upregulate 5‐HT2A receptor signaling by activation of the ERK1/2 signaling pathway. Activity of cortical 5‐HT2A receptors has been associated with several physiological functions and neuropsychiatric disorders such as stress response, anxiety and depression, and schizophrenia. Therefore, these results may provide a molecular mechanism by which activation of cannabinoid receptors might be relevant to the pathophysiology of some cognitive and mood disorders in humans. Synapse, 2013. © 2012 Wiley Periodicals, Inc.
Maternal serum placental growth factor at 11–13 weeks' gestation and fetal cardiac defects
Authors: Llurba E. , Syngelaki A. , Sánchez O. , Carreras E. , Cabero L. , Nicolaides K. H. 
Published: November 2012

ABSTRACTObjectiveTo investigate the relationship between fetal heart defects and maternal serum placental growth factor (PlGF), a marker of placental angiogenesis.MethodsMaternal serum PlGF, pregnancy‐associated plasma protein‐A (PAPP‐A) and uterine artery pulsatility index (UtA‐PI) at 11–13 weeks' gestation were compared in 68 cases of isolated fetal major heart defects and 340 normal controls. Variables were converted into multiples of the median (MoM) after adjustment for gestational age, maternal age, racial origin, weight, parity and method of conception, and then compared between groups. The cardiac defects included 11 cases of obstruction of the left ventricular outflow tract (LVOT), 25 conotruncal abnormalities and 32 valve defects.ResultsThe median PlGF‐MoM in the heart defect group was lower than in controls (0.80 (interquartile range (IQR), 0.57–1.08) vs 1.00 (IQR, 0.79–1.32); P < 0.0001). Low PlGF levels were observed in the presence of conotruncal and valve defects but not in the presence of LVOT defects. There was no significant difference between the group with fetal heart defects and controls in PAPP‐A‐MoM (0.95 (IQR, 0.68–1.28) vs 1.01 (IQR, 0.70–1.39); P = 0.292) or UtA‐PI‐MoM (1.01 (IQR, 0.84–1.28) vs 0.99 (IQR, 0.80–1.20); P = 0.396).ConclusionIn pregnancies with isolated fetal heart defects there is evidence of impaired placental angiogenesis in the absence of impaired placental perfusion and function. Copyright © 2012 ISUOG. Published by John Wiley & Sons Ltd.