bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functionalized Tri‐ and Tetraphosphine Ligands as a General Approach for Controlled Implantation of Phosphorus Donors with a High Local Density in Immobilized Molecular Catalysts
Authors: Beaupérin Matthieu , Smaliy Radomyr , Cattey Hélène , Meunier Philippe , Ou Jun , Toy Patrick H. , Hierso Jean‐Cyrille 
Published: August 2014

AbstractSupported phosphine ligands are auxiliaries of topical academic and industrial interest in catalysis promoted by transition metals. However, both controlled implantation and controlled conformation of ligands should be achieved to produce immobilized catalysts that are able to structurally “copy” efficient homogeneous systems. We provide herein a general synthetic strategy for assembling a new class of branched tetra‐ and triphosphine ligands with a unique controlled rigid conformation, and thus providing a high local density of phosphorus atoms for extended coordination to the metal center. We prepared new functionalized cyclopentadienyl (Cp) salts to design polyphosphines that were “ready for immobilization”. These protected Cp fragments might also be of synthetic utility for generating other supported metallocenes. Tetra‐ and triphosphines were then formed and diversely functionalized for immobilization on virtually any kind of support. As evidenced by 31P NMR spectroscopy and the strong “through‐space” spin–spin TSJ(P,P) coupling observed between P atoms, these modified polyphosphines induce, when immobilized on a support, a high local concentration of phosphorus donors that are spatially very close to each other (3–5 Å). These functionalized ligands have been incorporated into polystyrene to give either soluble or insoluble polymers and on inorganic supports such as silica. We report the catalytic performance at 0.05–0.5 mol % low palladium loading of the resulting immobilized polyphosphine ligands. This study provides proof‐of‐concept of supported catalytic materials built from modular polyphosphines with a novel approach to structurally controlled polydentate heterogeneous catalysts.
Selective C–N Bond‐Forming Reaction of 2,6‐Dibromopyridine with Amines
Authors: Wang Lei , Liu Ning , Dai Bin , Hu Hengcai 
Published: August 2014

AbstractA practical and efficient protocol for the syntheses of 6‐substituted 2‐bromopyridine compounds has been developed by using a selective copper‐catalyzed C–N bond‐forming reaction between 2,6‐dibromopyridine and a range of amines. The major advantage of this protocol is the complete control of selectivity of the pyridine bromine atom for the C–N cross‐coupling reaction. There are few reported syntheses of unsymmetrical 2,6‐disubstituted pyridine‐bridged compounds because of their complicated preparations. Although this is the case, a new series of these unsymmetrical compounds have been successfully prepared in two steps by using this copper‐catalyzed coupling approach.
Enantioselective Direct Bisvinylogous 1,6‐Additions of β‐Allyl‐2‐cyclohexenone to α,α‐Dicyanodienes through Trienamine Catalysis
Authors: Feng Xin , Zhou Zhi , Yin Xiang , Li Rui , Chen Ying‐Chun 
Published: August 2014

AbstractAn asymmetric direct ϵ‐regioselective bisvinylogous 1,6‐addition reaction of β‐allyl‐2‐cyclohexenone to β‐substituted α,α‐dicyanodienes was developed through trienamine catalysis of a bifunctional primary amine–thiourea compound. Excellent enantioselectivity (up to 97 % ee) was obtained even through such a remote reaction mode. In addition, more complex cyclic frameworks could be efficiently constructed with high stereoselectivity.
Gold Nanoparticles‐β‐Cyclodextrin‐Chitosan‐Graphene Modified Glassy Carbon Electrode for Ultrasensitive Detection of Dopamine and Uric Acid
Authors: Tang Jian , Zhang Lingling , Liu Yun , Zhou Jie , Han Guangqiang , Tang Weihua 
Published: August 2014

AbstractThe nanocomposite (denoted as GR‐AuNPs‐CD‐CS) of graphene (GR), gold nanoparticles (AuNPs), chitosan (CS) and β‐cyclodextrin (β‐CD) was prepared to modify a glassy carbon electrode. The as‐modified electrode was explored for the ultrasensitive detection of dopamine (DA) and uric acid (UA). The modified electrode demonstrated linearly increased current response in the concentration range of 0.1–120 µm for DA and 0.05–70 µm for UA, with so far the best detection limit for DA and UA. Good stability and repeatability were further demonstrated for the as‐made sensor.
Amperometric Sniffer for Volatile Amines Based on Paper‐Supported Room Temperature Ionic Liquids Enabling Rapid Assessment of Fish Spoilage
Authors: Toniolo Rosanna , Dossi Nicolò , Svigely Rossella , Susmel Sabina , Casella Innocenzo G. , Bontempelli Gino 
Published: August 2014

AbstractA gas sensors based on a room temperature ionic liquid (RTIL) supported on paper is proposed as amperometric sniffer for monitoring volatile amines (VAs) released from fish samples, in order to gain indication of their state of turning spoiled. It was used as a paper electrochemical detector (PED) for a flow injection system in which controlled headspace volumes in equilibrium with ice‐stored fish samples were directly injected. The performance of this RTIL‐PED sensor was preliminarily tested on synthetic samples of trimethylamine (TMA), dimethylamine (DMA), methylamine (MA) and ammonia (i.e. the main species responsible for the typical flavor of spoiled fish), thus verifying that only TMA, DMA and MA can be detected because NH3 oxidation occurred beyond the solvent discharge. This notwithstanding, detection of the sole TMA, DMA and MA as a whole turned out to be well suited for the rapid assessment of fish spoilage, since during storage the release enhancement for these amines is largely predominant over that of NH3. Repeatable (8 % RSD) sharp peaks were detected for all amines above over a wide range (5–1000 nmol) and a detection limit of a little more than 3 nmol was inferred for a signal‐to‐noise ratio of 3. This approach was applied to the detection of VAs released from real fish samples (sardines), in parallel to the determination of their total volatile basic nitrogen (TVBN), which is a conventional indicator frequently adopted for the chemical quality assessment of fish. A substantially satisfactory agreement was found by comparing the data achieved by these two approaches.
Experimental study of the effect of inhibitors in wax precipitation by different techniques
Authors: Coto Baudilio , Martos Carmen , Espada Juan José , Robustillo María Dolores , Peña José Luis 
Published: August 2014

AbstractThe blocking problems in equipment and flowlines caused by precipitation of wax solids is a well‐known problem and large research efforts have been focused on developing procedures dealing with wax deposition. Among the different alternatives, the use of chemicals is frequently used to inhibit wax precipitation. The presence of these compounds modifies the size and/or the shape of the paraffinic solids, thus affecting their flow behavior and cold properties. In this work, a methodology based on different experimental techniques was developed to study the effect of different additives on the crude oil behavior at low temperature. Four commercial inhibitors were added to three crude oils in different concentrations. The effect of the inhibitors on wax precipitation was studied using differential scanning calorimetry (DSC) and cross‐polarized microscopy (CPM). Obtained results for wax appearance temperature (WAT) using DSC do not show remarkable differences regarding the presence of inhibitor. However, CPM analyses revealed differences in both size and shape of paraffin solids. The results obtained in this work reveal that in some cases the inhibitor does not modify the WAT values, but the morphology of the precipitated particles. In these cases, it is necessary to combine DSC and CPM analyses to obtain reliable results.
Transformation and destabilization of graphene oxide in reducing aqueous solutions containing sulfide
Authors: Fu Heyun , Qu Xiaolei , Chen Wei , Zhu Dongqiang 
Published: August 2014

Abstract

The colloidal stability of carbon nanomaterials is a key factor controlling their fate and bioavailability in natural aquatic systems. The authors report that graphene oxide nanoparticles could be destabilized in reducing aqueous solutions containing a low concentration (0.5 mM) of sulfide, a naturally occurring reductant. Spectroscopic characterization using combined X-ray photoelectron, Fourier-transform infrared, X-ray diffraction, and Raman analyses revealed that the surface oxygen-containing groups (mainly epoxy groups) of graphene oxide were significantly reduced after reacting with sodium sulfide. The destabilization of graphene oxide was likely caused by the enhanced surface hydrophobicity of the reduced graphene oxide, whereas electrostatic repulsion played a minimal role. Solution pH was found to affect both the deoxygenation process and the aggregation behavior of graphene oxide. Coexisting humic acid reduced the reaction efficiency and stabilized graphene oxide through steric hindrance. These findings suggest for the first time that the colloidal behavior of carbon nanomaterials might change drastically when they enter natural reducing environments containing sulfide such as anaerobic aquifers and sediments. Environ Toxicol Chem 2014;33:2647–2653. © 2014 SETAC
Dissipation and residues of trifloxystrobin and its metabolite in rice under field conditions
Authors: Li Puyu , Wang Lin , Hao Xianghong , Han Lijun 
Published: August 2014

Abstract

Residue analysis of trifloxystrobin and its metabolite (CGA 321113) in rice matrices, paddy water, and soil was developed using the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method and high-performance liquid chromatography–tandem mass spectrometry. The method was used to evaluate the dissipation rate of trifloxystrobin and CGA 321113 in rice seedling, soil, and paddy water as well as the residual level in harvest rice (grain, hull, straw) and soil. The results demonstrated that the dissipation half-lives of trifloxystrobin in rice seedling, soil, and water were 1.9 d to 4.7 d, 0.35 d to 0.54 d, and 0.28 d to 0.51 d, respectively. The final total residue of trifloxystrobin and CGA 321113 was highest in rice hull and lowest in paddy soil. The highest total residues in husked rice, rice hull, straw, and paddy soil at 28 d after spraying were 0.39 mg kg−1, 3.82 mg kg−1, 0.29 mg kg−1, and 0.15 mg kg−1, respectively. According to the final residue data and the maximum residue limits of trifloxystrobin in rice grain and straw (Codex Alimentarius) and in rice hull (US Environmental Protection Agency), 28 d could be recommended as the preharvest interval for trifloxystrobin application in the rice field. The data show that CGA 321113 constitutes a small amount of the final total residues in rice matrices, whereas it is much higher than its parent compound in soil samples. Environ Toxicol Chem 2014;33:2654–2660. © 2014 SETAC
Lophirones B and C Extenuate AFB1‐Mediated Oxidative Onslaught on Cellular Proteins, Lipids, and DNA through Nrf‐2 Expression
Authors: Ajiboye Taofeek O. , Yakubu Musa T. , Oladiji Adenike T. 
Published: August 2014

ABSTRACTThe capability of lophirones B and C to extenuate aflatoxin B1 (AFB1)‐mediated onslaught on cellular proteins, lipids, and DNA was investigated for 6 weeks. Lophirones B and C significantly (P < 0.05) increase the expression and specific activity of cytoprotective enzymes (glutathione‐S‐trans‐ferase, nioctinamide adenine dicludeotide:quinone oxidoreductase‐1, epoxide hydrolase, and uridyl glucuronosyl transferase). There was significant (P < 0.05) reduction in the level of antioxidant system in AFB1‐induced hepatocarcinogenesis. Furthermore, lophirones B and C significantly (P < 0.05) attenuated AFB1‐mediated decrease in the specific activities of antioxidant enzymes. Oxidative stress biomarkers, malondialdehyde, lipid hydroperoxides, conjugated dienes, protein carbonyl, and fragmented DNA were significantly (P < 0.05) elevated in AFB1‐treated rats. Although lophirones B and C did not significantly (P < 0.05) alter these biomarkers, an AFB1‐mediated increase in these biomarkers was significantly attenuated. Results obtained showed that lophirones B and C extenuate AFB1‐mediated onslaught on cellular proteins, lipids, and DNA by enhancing nuclear erythroid–related factor‐2 expression.
Sonographic appearances of cervical lymph nodes in healthy young Japanese adults: Association with age, sex, and body mass index
Authors: Osanai Hizuru , Kuroiwa Hiroko , Uchida Keiichi , Kagami Hideaki , Yamada Kazuhiro , Taguchi Akira 
Published: August 2014

ABSTRACTPurposeWe investigated whether there was any association between age, sex, and body mass index (BMI) and nodal morphology and vascular pattern in healthy young Japanese adults.MethodsThree neck regions in 100 healthy subjects, 19–40 years old, were examined by gray‐scale and color Doppler sonography. Vascular pattern was classified into three groups: avascular, hilar, or scattered. A linear mixed‐effect model was used to identify associations of age, sex, or BMI with the short‐axis diameter and the short‐to‐long axis diameter ratio (S/L). A cumulative link mixed model was used to identify any association between age, sex, BMI, and vascular pattern.ResultsIn the upper cervical region, a decrease in the short‐axis diameter was statistically significantly associated with aging (p = 0.04), and an increase in the short‐axis diameter was significantly associated with greater BMI (p < 0.001). An increase in short‐axis diameter was significantly associated with female sex (p = 0.02) and higher BMI (p = 0.002) in the submandibular region, whereas it was associated with higher BMI (p = 0.001) in the submental region. A greater S/L was significantly associated with higher BMI and female sex in all regions. The scattered vascular pattern tended to be associated with lower BMI (p = 0.051) in the upper cervical region, but it was significantly associated with higher BMI (p = 0.01) in the submental region.ConclusionsNodal morphology and vascular pattern may be associated with age, sex, and BMI. © 2014 Wiley Periodicals, Inc. J Clin Ultrasound 43:295–301, 2015
SEM study of diversity in the cyst surface topography of nine parthenogenetic Artemia (Crustacea: Anostraca) populations from China
Authors: Asem Alireza , Sun Shi‐Chun 
Published: August 2014

ABSTRACTThe cysts of nine Chinese populations of parthenogenetic Artemia were studied by scanning electron microscope. In the 270 cysts examined, 15 different morphological patterns were recognized with most of them not recorded in previous studies and the “tubercled shell surface” being the most common pattern. Results also displayed high intrapopulation variability, with the maximum of 11 patterns (in 30 cysts) recorded from the Barkol population. No positive correlation between the diversity of cyst shell patterns and ploidy compositions was found. Principal components analysis suggests higher similarity among coastal populations than among inland populations, which may be attributed to the identity of physicochemical conditions among coastal salterns and dissimilarity among inland saline lakes. Microsc. Res. Tech. 77:1005–1014, 2014. © 2014 Wiley Periodicals, Inc.
Measurement of minimum angle of resolution (MAR) in the stereoscopic display using the optotype of stereoscopic stimuli
Authors: Shin Soo‐kyung , Jun Myung‐jin , Hong Hyungki 
Published: August 2014

AbstractIn stereoscopic images, the crossing point of the viewing directions of the two eyes determines the perceived depth. Assuming that accommodation is affected by the positions of the crossing point, the effect of crossing point on minimum angle of resolution (MAR) was investigated. For 40 participants, MAR was measured by two‐alternative forced choice where Snellen optotype E of up and down directions were used as two kinds of stimuli. As the crossing point of the viewing direction of the left and right eyes moves farther from the sample display, the ability to identify the direction of letter E decreases at the optotype of the same line thickness. The change of MAR shows linear trends with respect to the optical power change that are the reciprocal of the distance from the participant to the crossing points located out of screen and on screen.
Comparing Effectiveness of CPT to CPT‐C Among U.S. Veterans in an Interdisciplinary Residential PTSD/TBI Treatment Program
Authors: Walter Kristen H. , Dickstein Benjamin D. , Barnes Sean M. , Chard Kathleen M. 
Published: August 2014

AbstractCognitive processing therapy (CPT) is a leading cognitive–behavioral treatment for posttraumatic stress disorder (PTSD) and a front‐line intervention according to the U.S. Department of Veterans Affairs treatment guidelines. The original CPT protocol entails the creation of a written trauma account and use of cognitive therapy. Cognitive processing therapy–cognitive therapy only (CPT‐C) does not involve a written account and in a previous study resulted in faster symptom improvement and fewer dropouts than standard CPT. This study sought to replicate these findings by comparing the effectiveness of CPT to CPT‐C in a sample of 86 U.S. male veterans receiving treatment in a PTSD residential program for individuals with a history of traumatic brain injury. CPT and CPT‐C were delivered in a combined individual and group format as part of a comprehensive, interdisciplinary treatment program. Outcomes were self‐ and clinician‐reported PTSD and self‐reported depression symptoms. Multilevel analysis revealed no significant difference for PTSD symptoms, but did show a greater decrease in depression at posttreatment (d = 0.63) for those receiving CPT. When an experiment‐wise α correction was applied, this effect did not remain significant.
Acceptability of Prolonged Exposure Therapy Among U.S. Iraq War Veterans With PTSD Symptomology
Authors: Kehle‐Forbes Shannon M. , Polusny Melissa A. , Erbes Christopher R. , Gerould Heather 
Published: August 2014

AbstractDespite efforts to increase the availability of prolonged exposure therapy (PE) within the Department of Veterans Affairs, little is known about the acceptability of PE among veteran populations. We queried a sample of 58 U.S. National Guard Iraq War veterans previously deployed to combat who screened positive for posttraumatic stress disorder (PTSD) as to whether they would prefer PE, treatment with an antidepressant, or no treatment. We also gathered open‐ended responses regarding the veterans’ reasons for their choice and potential barriers to engaging in that treatment. A majority (53.4%) of veterans who completed the interview said they would choose to participate in PE, 36.2% preferred antidepressant treatment, 8.6% chose no treatment, and 1.8% were unable to choose among the options. Credibility of the treatment rationale and beliefs about the treatment's efficacy were the most frequently given reasons for choosing PE (45.2%); past treatment experience was the most common reason for choosing antidepressant treatment (47.6%). The most commonly cited barrier for those who chose both antidepressant treatment and PE was time to participate (52.4% and 77.4%, respectively). The findings suggest that PE is a credible and acceptable treatment option for veterans with PTSD symptomology.
Breathing‐Based Meditation Decreases Posttraumatic Stress Disorder Symptoms in U.S. Military Veterans: A Randomized Controlled Longitudinal Study
Authors: Seppälä Emma M. , Nitschke Jack B. , Tudorascu Dana L. , Hayes Andrea , Goldstein Michael R. , Nguyen Dong T. H. , Perlman David , Davidson Richard J. 
Published: August 2014

AbstractGiven the limited success of conventional treatments for veterans with posttraumatic stress disorder (PTSD), investigations of alternative approaches are warranted. We examined the effects of a breathing‐based meditation intervention, Sudarshan Kriya yoga, on PTSD outcome variables in U.S. male veterans of the Iraq or Afghanistan war. We randomly assigned 21 veterans to an active (n = 11) or waitlist control (n = 10) group. Laboratory measures of eye‐blink startle and respiration rate were obtained before and after the intervention, as were self‐report symptom measures; the latter were also obtained 1 month and 1 year later. The active group showed reductions in PTSD scores, d = 1.16, 95% CI [0.20, 2.04], anxiety symptoms, and respiration rate, but the control group did not. Reductions in startle correlated with reductions in hyperarousal symptoms immediately postintervention (r = .93, p < .001) and at 1‐year follow‐up (r = .77, p = .025). This longitudinal intervention study suggests there may be clinical utility for Sudarshan Kriya yoga for PTSD.
The Dopamine D3 Receptor Gene and Posttraumatic Stress Disorder
Authors: Wolf Erika J. , Mitchell Karen S. , Logue Mark W. , Baldwin Clinton T. , Reardon Annemarie F. , Aiello Alison , Galea Sandro , Koenen Karestan C. , Uddin Monica , Wildman Derek , Miller Mark W. 
Published: August 2014

AbstractThe dopamine D3 receptor (DRD3) gene has been implicated in schizophrenia, autism, and substance use‐disorders and is related to emotion reactivity, executive functioning, and stress‐responding, processes impaired in posttraumatic stress disorder (PTSD). The aim of this candidate gene study was to evaluate DRD3 polymorphisms for association with PTSD. The discovery sample was trauma‐exposed White, non‐Hispanic U.S. veterans and their trauma‐exposed intimate partners (N = 491); 60.3% met criteria for lifetime PTSD. The replication sample was 601 trauma‐exposed African American participants living in Detroit, Michigan; 23.6% met criteria for lifetime PTSD. Genotyping was based on high‐density bead chips. In the discovery sample, 4 single nucleotide polymorphisms (SNPs), rs2134655, rs201252087, rs4646996, and rs9868039, showed evidence of association with PTSD and withstood correction for multiple testing. The minor alleles were associated with reduced risk for PTSD (OR range = 0.59 to 0.69). In the replication sample, rs2251177, located 149 base pairs away from the most significant SNP in the discovery sample, was nominally associated with PTSD in men (OR = 0.32). Although the precise role of the D3 receptor in PTSD is not yet known, its role in executive functioning and emotional reactivity, and the sensitivity of the dopamine system to environmental stressors could potentially explain this association.
A Qualitative Analysis of the Experience and Impact of Killing in Hand‐to‐Hand Combat
Authors: Jensen Peter R. , Simpson Duncan 
Published: August 2014

AbstractA growing body of research suggests that killing during military combat is closely associated with posttraumatic stress disorder (PTSD), as well as a number of other adverse mental health related conditions (e.g., dissociative experiences, violent behavior, functional impairment). This article provides first‐person perspectives on the experiences and impact of killing by service members with the goal of expanding our understanding of the impact of taking a life during war. In audio‐recorded phenomenological interviews, 9 service members described their experiences and the subsequent impact of killing during hand‐to‐hand combat. A description, supported by participant quotations, was constructed to represent the participants’ experiences. Results suggest the experience and aftermath of taking a life in hand‐to‐hand combat was disturbing, psychologically stressful, and necessitated some form of coping after the event. Service members who killed in hand‐to‐hand combat viewed their actions as necessary to preserve their life and that killing in hand‐to‐hand combat was more emotionally taxing than killing by shooting. Our findings may help to improve providers' understanding of service members’ first‐person experiences of killing in hand‐to‐hand combat and thus provide the basis for the development of a connected and genuine relationship with such military clients.