bluuebunny/crossref_metadata_2025 huggingface dataset:
Facile Synthesis and Lateral π-Expansion of Bisanthenes
Authors: Konishi Akihito , Hirao Yasukazu , Matsumoto Kouzou , Kurata Hiroyuki , Kubo Takashi
Published: May 2013

The improved Scholl reaction allows for the direct cyclization of anthracene oligomers to give bisanthene, teranthene, and quateranthene. Furthermore, a variety of π-expanded bisanthenes are obtained by the Diels–Alder cycloaddition of bisanthene with several arynes. These reactions would allow us to synthesize various size- and shape-controlled polyperiacenes.
Promises and challenges of pharmacogenetics: an overview of study design, methodological and statistical issues
Authors: Ross Stephanie , Anand Sonia S , Joseph Philip , Paré Guillaume
Published: May 2013

Pharmacogenetics is the study of inherited variation in drug response. The goal of pharmacogenetics is to develop novel ways of maximizing drug efficacy and minimizing toxicity for individual patients. Personalized medicine has the potential to allow for a patient's genetic information to predict optimal dosage for a drug with a narrow therapeutic index, to select the most appropriate pharmacological agent for a given patient and to develop cost-effective treatments. Although there is supporting evidence in favour of pharmacogenetics, its adoption in clinical practice has been slow because of sometimes conflicting findings among studies. This failure to replicate findings may result from a lack of high-quality pharmacogenetic studies, as well as unresolved methodological and statistical issues. The objective of this review is to discuss the benefits of incorporating pharmacogenetics into clinical practice. We will also address outstanding methodological and statistical issues that may lead to heterogeneity among reported pharmacogenetic studies and how they may be addressed.
Silent brain infarction in the presence of systemic vascular disease
Authors: Slark Julia , Bentley Paul , Sharma Pankaj
Published: May 2013

Objective

To determine the prevalence of asymptomatic brain ischaemic in the presence of vascular disease in other arterial territories.

Design

Studies up to January 2011 were identified through comprehensive search strategies. Arcsine transformation for metaanalysis was used to calculate the standardized mean difference (SMD) and 95% confidence intervals (CI).

Setting

A systematic review and meta-analysis were performed.

Participants

For each study, the proportion of patients positive for SBI in the presence of other systemic vascular disease was extracted and analyzed.

Main outcome measures

Using a random-effects model, a pooled effect estimate interpreted as a percentage prevalence of disease was calculated.

Results

SBI in the presence of acute ischaemic stroke was found in 23% (SMD 0.99; P < 0.001; 95% CI 0.88-1.10); a 35% prevalence was found in patients with coronary artery disease (SMD 1.26; P < 0.001; 95% CI 0.95-1.58); and a 14% prevalence in patients with peripheral artery disease (SMD 0.48; P< 0.002; 95% CI 0.42-0.54), although the data-set in the latter is smaller.

Conclusions

Patients with systemic vascular disease are at an increased risk of silent brain infarction.
Adrenomedullin and cardiovascular diseases
Authors: Wong Hoi Kin , Cheung Tommy Tsang , Cheung Bernard M Y
Published: May 2013

Summary

The cardiovascular system is regulated by the autonomic nervous system, the renin–angiotensin–aldosterone system, nitric oxide (NO) and other factors including neuropeptides. Research in neurohumoral factors has led to the development of many cardiovascular drugs. Adrenomedullin (ADM), initially isolated from the adrenal gland, has diverse physiological and pathophysiological functions in the cardiovascular system. It is produced in many organs and tissues including the vasculature. ADM has numerous actions, including vasodilation, natriuresis, antiapoptosis and stimulation of NO production. It might play a protective role in various cardiovascular pathologies, and its plasma level is elevated in patients with hypertension and heart failure. Administration of ADM is a possible therapeutic approach for treating cardiovascular diseases. A number of studies have investigated the infusion of ADM in humans, which seems to be benficial in heart failure and myocardial infarction. Instead of ADM infusion, augmentation of its endogenous level is another possible strategy. Gene therapy is feasible in animal models, but its application in humans is limited. At present, the most promising clinical application of ADM is the use of the plasma level of mid-regional proadrenomedullin as a biomarker in cardiovascular diseases. It is a good marker of prognosis and survival in patients with coronary aretery disease or heart failure.
Diagnostic confusion resolved by being upbeat
Authors: Kakar Puneet , Kamdar Ami , Prabhudev Hemanth , Buddha Sandeep , Kaski Diego , Bentley Paul
Published: May 2013

The classical stroke presentation – captured by the public health campaign mnemonic FAST (face, arm, speech, time) – does not apply in a large number of stroke cases; yet establishing a prompt diagnosis is imperative for optimal management. Here, we describe a patient with acute bulbar weakness, numbness in all extremities and an apparently normal magnetic resonance imaging (MRI) of the brain upon admission for whom even the fundamental question of whether this reflected a central or peripheral nervous system process was unclear. The critical localizing sign was upbeat nystagmus that denotes a brainstem cause. MRI of the brain in the second week confirmed a diagnosis of medial medullary infarction.
A retrospective case-control study of modifiable risk factors and cutaneous markers in Indian patients with young coronary artery disease
Authors: Aggarwal Amitesh , Aggarwal Sourabh , Goel Ashish , Sharma Vishal , Dwivedi Shridhar
Published: May 2013

Objective

Indians have the highest risk rates for coronary artery disease (CAD) among all ethnic groups. There is a paucity of data on the risk factors and clinical markers associated with premature CAD. We aimed to determine whether young CAD is due to preventable lifestyle-related factors and cutaneous clinical markers are useful in identifying at-risk patients.

Design

Single-centre retrospective study.

Setting

Tertiary care center.

Participants

A total of 292 patients (age ≤40 years) who presented with acute CAD between January 2005 and June 2009 and 92 age, and gender-matched controls.

Major outcome measures

Details of smoking, family history of premature CAD, waist size, blood sugar and lipid profile. Clinical evidence of arcus juvenilis, premature greying of hair and premature baldness sought.

Results

Dyslipidaemia (91%), smoking (74.3%), low high-density lipoprotein cholesterol (HDL-C) (68.9%), central obesity (47.7%) and greying of hair (34.9%) were the most commonly associated factors. Compared with male patients, females had greater prevalence of dyslipidaemia, low HDL-C, central obesity, hypertension, diabetes and family history of premature CAD. The presence of cutaneous markers was significantly associated with premature CAD.

Conclusions

CAD in young Indian people is multifactorial; dyslipidaemia, low HDL-C, smoking, hypertension, central obesity and family history of premature CAD are the most common risk factors. Smoking in men and central obesity in women are the most prevalent factors. Clinicians should be highly suspicious of patients with presence of cutaneous markers, and they should be followed intensively for lifestyle modifications.
Normal levels of inflammatory markers in treated patients with familial hypercholesterolaemia: a cross-sectional study
Authors: Seed Mary , Betteridge D John , Cooper Jackie , Caslake Muriel , Durrington Paul N , Thompson Gilbert R , Sattar Naveed , Humphries Steve E , Neil H Andrew W
Published: May 2013

Objective

To assess the relationship of levels of inflammatory risk markers to presence of clinical coronary artery disease (CAD) in patients with treated heterozygous familial hypercholesterolaemia.

Design

A cross-sectional study of patients on the Simon Broome Familial Hyperlipidaemia Register.

Setting

Six hospital outpatient clinics in the UK.

Participants

A total of 211 men and 199 women with heterozygous familial hypercholesterolaemia.

Main outcome measures

Analysis of conventional risk factors and concentrations of high-sensitivity C-reactive protein (hsCRP), lipoprotein (a), serum intercellular adhesion molecule (sICAM), interIeukin-6 (IL-6) and lipoprotein-associated phospholipase A2 (LpPLA2) mass.

Results

CAD was present in 104 men and in 55 women; the mean ages of onset were 43.1 and 46.5 years, respectively. On univariate analysis there was a positive relationship of CAD with age, male sex, smoking, IL-6 and sICAM, and an inverse relationship with low-density lipoprotein (LDL) and LpPLA2. On multivariate analysis, age, smoking, low LDL and low LpPLA2 were associated with CAD. When LpPLA2 values were adjusted for apoB and aspirin usage, there was no significant difference between those with and without CAD. Only age and smoking were independently associated with CAD in men, and IL-6 and lipoprotein(a) in women.

Conclusions

Although on univariate analysis inflammatory marker levels were associated with CAD in these patients, the majority of the associations, including that for hsCRP, disappeared when corrected for smoking and apoB. This may be because atherosclerotic plaques in these statin-treated patients were quiescent or an effect of aspirin usage. In this observational study newer risk markers were not usefully associated with the presence or absence of symptomatic CAD.
The physician's role in prescribing physical activity for the prevention and treatment of essential hypertension
Authors: Brooks John H M , Ferro Albert
Published: May 2013

Blood pressure control and prevention of hypertension can be achieved by both pharmacological and lifestyle interventions; one important lifestyle intervention is physical activity. Participation in regular physical activity can modestly lower blood pressure by reducing total peripheral resistance; it can also reduce the risk of developing hypertension and improve morbidity and mortality outcomes. Therefore, physical activity is a recommended intervention for the majority of hypertensive or prehypertensive patients. The precise level of physical activity required to lower blood pressure is unknown; however, in the UK, national minimum physical activity guidelines would seem appropriate for most hypertensives. Current patient physical activity levels can be assessed easily using retrospective recall questionnaires; preparticipation screening and exercise modifications for high-risk patients may reduce the risk of adverse events during subsequent exercise; and identification of a patient's willingness to increase physical activity levels may help to tailor physical activity advice. Health professional counselling or advice on physical activity is currently the most effective researched intervention. Its success can be maximized by delivering physical activity advice and counselling multiple times using different health professionals in person or over the telephone and by offering additional written materials. While the most effective methods for increasing physical activity levels in patients are probably still unclear, physical activity is an advisable intervention for the majority of hypertensive patients.
Personalized antiplatelet therapy: state of the art
Authors: Gurbel Paul A , Jeong Young-Hoon , Tantry Udaya S
Published: May 2013

Overwhelming evidence exists that thrombus generation resulting from platelet activation and aggregation is the primary process involved in the occurrence of the myocardial infarction and stent thrombosis. Despite the proven clinical efficacy of dual antiplatelet therapy, wide antiplatelet response variability associated with clopidogrel therapy was demonstrated in pharmacodynamic studies where approximately one in three patients exhibited high on-treatment platelet reactivity (HPR). Generally, physicians do not objectively assess the intensity of the adenosine diphosphate–P2Y12 interaction in their high-risk patients treated with clopidogrel. Instead most clinicians use a non-selective or one-size-fits-all approach. HPR and CYP2C19 LoF carriage are associated with clinical outcomes in high-risk clopidogrel-treated patients who have undergone percutaneous coronary intervention (PCI). Although we do no yet have conclusive evidence from a large-scale randomized trial that personalized antiplatelet therapy improves patient outcomes, a class IIb recommendation has been given in the guidelines to perform genotyping or phenotyping in high-risk PCI patients if a change in antiplatelet therap will ensue based on the test results. It may be reasonable at this time to assess platelet function and perform genotyping in clopidogrel-treated high-risk patients and treat with more potent P2Y12 receptor therapy selectively.
Modern management of a patent foramen ovale
Authors: Kanaganayagam G S , Malik I S
Published: May 2013

A patent foramen ovale (PFO) has been associated with medical conditions such as cryptogenic stroke, migraine with aura, and decompression illness. Whether closure of the PFO has clinical benefit has been suggested from registry studies, but not yet confirmed in multiple randomized trials. Methods of diagnosis of a PFO and a summary of the current evidence for treatment is presented and discussed as a guide to patient-centred decision-making.
Anticoagulation in atrial fibrillation: the present and the future
Authors: Dweck Marc R , Shah Anoop S V , Fox Keith A A
Published: May 2013

Atrial fibrillation (AF) is the most common form of cardiac arrhythmia and associated with significant mortality and morbidity. It is a powerful predictor of future embolic stroke, such that anticoagulation is recommended in the majority of patients. For many years this has predominantly been in the form of vitamin K antagonists. However, there are well-documented difficulties with their administration that result in poor compliance and high discontinuation rates. Over recent years several oral alternative anticoagulant agents have become available with the potential to overcome many of these pitfalls. In this review, we discuss current recommendations for anticoagulant therapy in AF and how these may change in the future with the introduction of novel therapeutic options.
Cerebrovascular disease in South Asia – Part I: A burning problem
Authors: Prasad Kameshwar , Vibha Deepti , Meenakshi
Published: May 2013

Stroke is a non-communicable disease of increasing socioeconomic importance in ageing populations. According to the World Health Organization, stroke was the second most common cause of worldwide mortality. In South Asian countries demographic changes, urbanization and increased exposure to major stroke risk factors will fuel the stroke burden in the future. The prevalence of stroke in India is 44–843/100,000 (from community-based studies), 500–2000/100,000 in Bangladesh, 218/100,000 in Pakistan and 1000/100,000 in Sri Lanka and community-based prevalence studies in these countries are still lacking. There are no data on stroke prevalence from Nepal. Incidence studies are still less and an Indian study reported an incidence of 145/100,000. Incidence studies from other South Asian countries are lacking. This review attempts to give an overview of the evidence so far on the burden of stroke in this part of the globe.
The spliceosome catalyzes debranching in competition with reverse of the first chemical reaction
Authors: Tseng Chi-Kang , Cheng Soo-Chen
Published: May 2013

Splicing of nuclear pre-mRNA occurs via two steps of the transesterification reaction, forming a lariat intermediate and product. The reactions are catalyzed by the spliceosome, a large ribonucleoprotein complex composed of five small nuclear RNAs and numerous protein factors. The spliceosome shares a similar catalytic core structure with that of fungal group II introns, which can self-splice using the same chemical mechanism. Like group II introns, both catalytic steps of pre-mRNA splicing can efficiently reverse on the affinity-purified spliceosome. The spliceosome also catalyzes a hydrolytic spliced-exon reopening reaction as observed in group II introns, indicating a strong link in their evolutionary relationship. We show here that, by arresting splicing after the first catalytic step, the purified spliceosome can catalyze debranching of lariat-intron-exon 2. The debranching reaction, although not observed in group II introns, has similar monovalent cation preferences as those for splicing catalysis of group II introns. The debranching reaction is in competition with the reverse Step 1 reaction influenced by the ionic environment and the structure of components binding near the catalytic center, suggesting that the catalytic center of the spliceosome can switch between different conformations to direct different chemical reactions.
Morphometry Analysis of Lymphatics in Pulmonary Adenocarcinomas With a Lepidic Growth Pattern
Authors: Sannier Aurélie , Kambouchner Marianne , Danel Claire , Callard Patrice , Bernaudin Jean-François
Published: May 2013

Lymph vessels play an important role in tumor progression. Pulmonary adenocarcinomas, accounting for half of non-small-cell lung carcinomas, compose a spectrum of histological types, exclusively or without a lepidic growth pattern (LGP) along preserved interalveolar septa. In that context, this study was designed to investigate the lymphatic vascular pattern associated with LGP and the concomitant invasive component of pulmonary adenocarcinomas. Using the D2-40 monoclonal antibody as a marker of lymphatic endothelial cells, the lymphatic vessel density (LVD) and vessel-area fraction (LVAF) were morphometrically analyzed in four adenocarcinomas in situ (AIS) and the LGP of eight invasive adenocarcinomas (LPIA), and compared with their invasive pattern (IPIA). LVD in AIS (2.1 ± 0.7 mm−2) and LPIA (2.4 ± 1 mm−2) were significantly lower than that in IPIA (14.9 ± 13.6 mm−2) ( p=0.001). Moreover, the lymphatic vascular pattern in LGP was similar to that of normal lung, with isolated small lymphatic vessels within the interalveolar septa. Our results showing the scarcity of lymphatics in LGP suggest an absence of septal lymphangiogenesis associated with the LGP pattern in lung adenocarcinomas, which could explain, at least partially, the better prognosis observed in tumors with exclusive or predominant lepidic spread compared with other subtypes.
Crystal structure of 6-cyclohexyl-5H-[1,3]dithiolo[4,5-f]isoindole-2,5,7- (6H)-trione, C15H13NO3S2
Authors: Guo Chang-Bin , He Yang , Hou Zhen-Geng , Li Zhen-Zhong
Published: May 2013

C15H13NO3S2, triclinic, P1̅ (no. 2), a = 5.5064(6) Å, b = 10.075(1) Å, c = 13.844(1) Å, α = 104.474(9)°, β = 92.046(8)°, γ = 101.598(8)°, V = 725.5 Å3, Z = 2, Rgt(F) = 0.0419, wRref(F2) = 0.0987, T = 296 K.
Redetermination of the structure of 4-amino-benzonitrile, C7H6N2
Authors: Islor Arun M. , Chandrakantha B. , Gerber Thomas , Hosten Eric , Betz Richard
Published: May 2013

C7H6N2, monoclinic, P21/c (no. 14), a = 7.2382(6) Å, b = 5.4770(4) Å, c = 16.040(2) Å, β = 101.680(4)°, V = 622.7 Å3, Z = 4, Rgt(F) = 0.0500, wRref(F2) = 0.1377, T = 200 K.
Crystal structure of ammonium 5-carboxypicolinate monohydrate, C7H10N2O5
Authors: Gerber Thomas , Betz Richard
Published: May 2013

C7H10N2O5, triclinic, P1 (no. 1), a = 3.7899(2) Å, b = 6.1661(3) Å, c = 9.3089(4) Å, α = 91.876(2)°, β = 92.926(2)°, γ = 90.872(2)°, V = 217.1 Å3, Z = 1, Rgt(F) = 0.0298, wRref(F2) = 0.0784, T = 200 K.
Redetermination of the crystal structure of N-acetyl glycine (2-acetamidoacetic acid), C4H7NO3
Authors: Saronjini B. K. , Narayana Badiadka , Yathirajan Hemmige S. , Gerber Thomas , Hosten Eric , Betz Richard
Published: May 2013

C4H7NO3, monoclinic, P21/c (no. 14), a = 4.8110(2) Å, b = 11.5030(5) Å, c = 9.7660(4) Å, β = 97.864(2)°, V = 535.4 Å3, Z = 4, Rgt(F) = 0.0356, wRref(F2) = 0.1099, T = 200 K.
Crystal structure of bis(2-phenylpyridin-1-ium)hexabromidoplatinate(IV) dihydrate, C22H24Br6N2O2Pt
Authors: Ha Kwang
Published: May 2013

C22H24Br6N2O2Pt, triclinic, P1¯ (no. 2), a = 7.711(1) Å, b = 9.078(2) Å, c = 11.018(2) Å, α = 69.643(4)°, β = 71.268(4)°, γ = 78.109(4)°, V = 680.9 Å3, Z = 1, Rgt(F) = 0.0317, wRref(F2) = 0.0718, T = 200 K.
Crystal structure of bis(µ-6-olato-2,2'-bipyridine-κ3N,N':O)-dicopper(I) —pentafluorotantalum(V) (1:1), [Cu2(C10H7N2O)2][TaF5], C20H14Cu2F5N4O2Ta
Authors: Zhong Zhi-Guo , Li Jing , Song Jin-Fan
Published: May 2013

C20H14Cu2F5N4O2Ta, monoclinic, C2 (no. 5), a = 18.372(9) Å, b = 3.860(2) Å, c = 16.038(8) Å, β = 115.086(7)°, V = 1029.9 Å3, Z = 2, Rgt(F) = 0.0407, wRref(F2) = 0.1083, T = 296 K.
Crystal structure of 3-(bis(benzylthio)methylene)pentane-2,4-dione, C20H20O2S2
Authors: Guo Mengping , Zhu Zhiyong , Wu Xiaochun , Ge Junying
Published: May 2013

C20H20O2S2, monoclinic, C2/c (no. 15), a = 11.478(8) Å, b = 11.757(8) Å, c = 14.39(1) Å, β = 101.08(2)°, V = 1905.8Å3, Z = 4, Rgt(F) = 0.0448, wRref(F2) = 0.1433, T = 293 K.
Crystal structure of 5-iodo-1-tosylpyrimidine-2,4(1H,3H)-dione, C11H9IN2O4S
Authors: Li Da-Shuai , Yi Ji-Cheng , Shao Liang-Ping , Zhao Ya-Juan , Xiong Jing
Published: May 2013

C11H9IN2O4S, monoclinic, P21/c (no. 14), a = 14.771(3) Å, b = 4.8338(8) Å, c = 23.234(3) Å, β = 125.874(8)°, V = 1344.3 Å3, Z = 4, Rgt(F) = 0.0265, wRref(F2) = 0.0885, T = 298 K.
Le Naufrage de la Méduse and Operatic Spectacle in 1830s Paris
Authors: Hibberd Sarah
Published: May 2013

Grand opera's love of all-consuming spectacle is evident in its cataclysmic eruptions, explosions, and shipwrecks, its magnificent processions and ceremonies, and its breathtaking reconstructions of sublime landscapes, from Auber's La Muette de Portici (1828), through Halévy's La Juive (1835), to Meyerbeer's Le Prophète (1849), and beyond. An understanding of the Parisian public's visual experiences and expectations outside the opera house can help in theorizing grand opera's distinctive aesthetic.

Contemporary spectacles d'optique, including the tableau vivant, panorama, diorama, and nocturnorama, attest to the higher powers of sensory attentiveness demanded of audiences. Some offered a sensory overload that encouraged complete absorption in the spectacle; others encouraged critical reflection as music and image drew attention to themselves through a disjunction of narrative or mood. Auguste Pilati and Friedrich von Flotow's opera Le Naufrage de la Méduse (Théâtre de la Renaissance, 1839) incorporated an ambitious animated representation of Théodore Géricault's celebrated painting on the subject and generated critical discussion about the relationship between sound and vision. Le Naufrage and the spectacles d'optique of the period offer a prism through which to view opera's evolution from a contemplative to a more involving form of drama in the second quarter of the nineteenth century, and to contextualize French grand opera's distinctive fascination with the interplay of music and spectacle, narrative and display, and the engagement of audiences in constructing meanings.
Efficacy and safety of LB03002, a once-weekly sustained-release human GH for 12-month treatment in Korean children with GH deficiency
Authors: Hwang Jin Soon , Lee Hae Sang , Chung Woo Yeong , Han Heon-Seok , Jin Dong-Kyu , Kim Ho-Seong , Ko Cheol-Woo , Lee Byung-Churl , Lee Dae-Yeol , Lee Kee-Hyoung , Shin Jeh-Hoon , Suh Byung-Kyu , Yoo Han-Wook , Ji Hyi-Jeong , Lee Jin-Hwa , Bae Yoon Ju , Kim Duk-Hee , Yang Sei Won
Published: May 2013

Purpose

The purpose of this study was to investigate the efficacy and safety of LB03002, a sustained-release human GH (SR-hGH), compared with that of daily rhGH for 12 months in children with GH deficiency (GHD).

Methods

A total of 73 children with GHD were screened and 63 eligible subjects were randomized in a 1:1 ratio of LB03002 (SR-hGH) to daily rhGH treatment group. LB03002 was administered once weekly at a dose of 0.5 mg/kg while daily rhGH was administered for 6 consecutive days with equally divided doses to make a total of 0.21 mg/kg per week. Treatments were given for 12 months by s.c. injections. Injection site reactions and adverse events were investigated throughout the study period.

Results

The mean (s.d.) height velocity (HV) showed a clinically significant increase after the 6-month treatment: 3.00 (1.15) cm/year at screening to 9.78 (1.98) cm/year at 6 months in the LB03002 group; 2.39 (1.63) cm/year at screening to 10.56 (2.65) cm/year at 6 months in the daily rhGH group. The increased HV at 12 months was still maintained in both the groups: 9.06 (1.63) cm/year at 12 months in the LB03002 group; 9.72 (2.32) cm/year at 12 months in the daily rhGH group. Most of the adverse drug reactions were mild and tolerable. No subjects were withdrawn due to adverse events.

Conclusion

Weekly injection of LB03002 at a dose of 0.5 mg/kg per week was confirmed to have comparable efficacy to daily injection of rhGH at a dose of 0.21 mg/kg per week. Both formulations were well tolerated.
A quantitative enquiry into the translator’s job-related happiness: Does visibility correlate with happiness?
Authors: Liu Christy
Published: May 2013

The translator’s job-related happiness has scarcely been researched in empirical Translation Studies. This article presents part of the findings from a large empirical study in which a mixed method approach (i.e. quantitative and qualitative approaches are combined) is employed to study the topic. The analysis is based on a questionnaire answered by 193 Chinese translators in greater China. This study statistically shows that the more visible the translator, the happier they are. In addition, the more visible the translator, the less the gap between capital sought and capital received. We also confirm the hypothesis that the more visible the translator, the more and greater positive emotions they experience when they deal with translation.
The (100) surface of the Al13Co4 quasicrystalline approximant
Authors: Fournée Vincent , Gaudry Émilie , de Weerd Marie-Cécile , Diehl Renee D. , Ledieu Julian
Published: May 2013

The structure of the (100) surface of the orthorhombic Al13Co4quasicrystalline approximant is described based on a combined scanning tunneling microscopy (STM), low-energy electron diffraction (LEED), and density functional theory (DFT) study. We discuss the interplay between the surface structure and the cluster substructure of this approximant as well as possible off-stoichiometry effects that could explain the discrepancies found in the literature on possible surface models.
Non-existence Fullerene Compounds
Authors: Salcedo Roberto
Published: May 2013

A brief summary about the research lines of our group is presented. The common factor in all the propositions is the fullerene in a chemical reactive role. The chemistry proposed is novel and can yield interesting results.
Effect of Mesogenic Organic Salts on Vulcanization and Physical Properties of Natural Rubber Compounds
Authors: Avalos F. , Tellez-Rosas M. , Castañeda-Flores M.E. , Martínez-Casado F. J. , Rodríguez-Cheda J. A. , Arroyo M. , López-Manchado M. A.
Published: May 2013

The effect of mesogenic organic salts as reinforcing fillers for natural rubber has been investigated. The influence of cation size (thallium and sodium) and organic chain length (thallium (I) pentanoate and dodecanoate) on the vulcanization parameters, physical and mechanical characteristics and rheological behavior has also been analyzed. In general, the maximum torque of the vulcanizates increases in the presence of the salts and is clearly manifested in a sensible increase in tensile modulus and strength of the composites. The reinforcing effect of these salts is noticeable in the natural rubber matrix. The thallium (I) salts are more effective reinforcements than the sodium salt, and the length of the organic chain hardly has any influence on the mechanical properties. The composites based on the thallium (I) dodecanoate salt show a very peculiar rheological behavior with a “plateau” in the G’ and G” vs temperature graphics which is related with solid phase I, existing between 83.5 ºC and 127 ºC, characterized as a plastic condis phase. This issue is especially interesting for the fabrication of devices such as sensors to control, for instance, the security (resistance of a material) as a function of temperature.
Radiation-Grafting of Cotton-g-DMAEMA for Biomedical Applications
Authors: Luna-Straffon Marco A. , Cedillo Gerardo , Bucio Emilio
Published: May 2013

This work covers the design of stimuli-responsive membranes and their ever-expanding range of use. Stimuli-responsive membranes that change their physicochemical properties in response to changes in their environment were synthesized for biomedical application. Responsive cotton-g-[2-(dimethylamino) ethyl methacrylate] membranes were obtained using γ-rays by mutual irradiation (direct method). The effect of absorbed dose, dose rate, and monomer concentration on the grafting yield was determined. The grafted samples were verified by the FTIR-ATR, 1H and 13C HRMAS NMR and 13C CPMAS NMR spectroscopies; thermal properties were analyzed by TGA and DSC and the stimuli-responsive behavior was studied by DSC.
Electrostatic Spray Deposition of Highly-Crystalline TIPS Pentacene Thin Films for Fabrication of Organic Field-Effect Transistors
Authors: Onojima Norio , Saito Hiroki , Nishio Naomichi , Kato Takamasa
Published: May 2013

This paper demonstrates that electrostatic spray deposition (ESD) method is a promising solution process to fabricate highly-crystalline organic films (6,13-bis(triisopropylsilylethynyl) pentacene; TIPS pentacene) for the use in bottom-contact organic field-effect transistors (OFETs). We obtained large crystalline domains (i.e., molecularly-oriented domains) by using an o-DCB:acetone mixed solvent (1:1), and observed good transistor behavior in an OFET having the channel length of 20 μm.
Cross-plane thermal conductivity temperature dependence for PbSnSe/PbSe thin film superlattice material from 100K to 300K
Authors: Jeffers James D. , Olona Leonard , Cai Zhihua , Namjou Khosrow , McCann Patrick J.
Published: May 2013

The temperature dependence of cross-plane lattice thermal conductivity for thin film IV-VI semiconductors grown by molecular beam epitaxy was measured. Samples consisting of PbSe/PbSrSe multiple quantum wells (MQWs) on PbSe/PbSnSe superlattices (SLs) were grown with variations in SL layer thickness and the number of SL pairs. Localized lattice temperatures within the MQW layers were extracted from analysis of continuous wave photoluminescence (PL) emission spectra at heat sink temperatures between 100 K and 250 K. These data, finite element analysis, and electrical characterization were used to determine cross-plane lattice thermal conductivity of two different SL materials. A SL material with three different PbSe/PbSnSe thicknesses (1.2/1.2, 1.8/1.8, and 2.4/2.4 nm) exhibited a fairly constant lattice thermal conductivity from 1.2 to 1.3 W/mK as the sample was cooled from 250 K to 100 K. Another SL material with five different PbSe/PbSnSe thicknesses (0.5/0.5, 1.0/1.0, 1.6/1.6, 2.1/2.1, and 2.6/2.6 nm) exhibited very low lattice thermal conductivities from 0.46 to 0.47 W/mK 250 K to 100 K. These results are consistent with reflection of low energy heat transporting acoustic phonons within the SL material.
Photothermal microscopy applied to the characterization of UO2-Gd2O3 nuclear fuel pellets
Authors: Martínez Oscar , Zaldivar Facundo , Mingolo Nélida , Kempf Rodolfo
Published: May 2013

The photothermal photodeflection technique is shown to provide information on the homogeneity of fuel pellets, pore distribution, clustering detection of pure urania and gadolinea and to provide a two-dimensional mapping of the thermal diffusivity correlated to the composition of the interdiffused Gadolinium and Uranium oxide. Histograms of the thermal diffusivity distribution become a reliable quantitative way of quantifying the degree of homogeneity and the width of the histogram can be used as a direct measure of the homogeneity. These quantitative measures of the homogeneity of the samples at microscopic levels provides a protocol that can be used as a reliable specification and quality control method for nuclear fuels, substituting with a single test a battery of expensive, time consuming and operator dependent techniques.
Seebeck Coefficient of Nanolayer Growth of Anatase TiO2-x/Al-foil by Atomic Layer Deposition
Authors: Chamberlin Matthew , Ahern Renee E. , Constantin Costel
Published: May 2013

Non-stoichiometric and impurity doped titanium dioxide materials are good candidates for use in high temperature thermoelectric devices. Nanolayers of non-stoichiometric (TiO2-x) thin films were deposited on Al-foil by atomic layer deposition growth method. X-ray diffraction experiments showed anatase phase for these nanolayers. This crystal structure was maintained even after an annealing treatment of 600 °C for 60 minutes under an O2 pressure of ∼ 10 psi. This investigation presents for the first time how Al-foil can be functionalized by manipulating the Seebeck coefficient of these TiO2-x nanolayers.
Photoprotection of Chlorophyll-a by Gold Nanoparticles
Authors: Bekale Laurent , Barazzouk Saïd , Hotchandani Surat
Published: May 2013

The photoprotection of Chlorophyll-a (Chla) is important for its utilization in light harvesting assemblies. Photodegradation effects seen in the Chla solution appear to be inhibited due to the incorporation of Au nanoparticles. The protecting ability of Chla by AuNPs is the result of their efficient binding with Chla at its nitrogen sites even in dark, thus, inhibiting the reaction of reactive oxygen species with Chla, known to cause its degradation during illumination.
The Wide band p- type material formed by the thin film with ZnO - NiO mixed crystal system
Authors: Nishitani Mikihiko , Sakai Masahiro , Morita Yukihiro
Published: May 2013

We study ZnO-NiO mixed crystal thin film as a wide band p-type material for the hetero-junction with ZnO. As for the hetero-junction of the ZnO ( n-type ) and the NiO which have relatively stable p-type semiconductor characteristics, there are issues on the crystallographic mismatch and the band offset of the valence band as well as the conduction band . We made the ZnO-NiO mixed crystal thin film in all composition range with the substrate temperature of 250°C, using magnetron sputtering process and acquired the basic data for the change of electrical conductivity with conduction type. In addition, a high-quality thin film was made by using a Pulse Laser Deposition ( PLD ) , and the band diagram of the ZnO-NiO mixed crystal system was illustrated from the analyses of XPS, NEXAFS and optical absorption measurements. As a result, the offset of ZnO-NiO mixed crystal film is proportionally decreasing with increasing the content of ZnO in NiO film. And the characteristics of the diode with the hetero-junction of ZnNiO/ZnO were improved compared with that of NiO/ZnO. The reasons were discussed with the data of the band offset, the crystalline of the films and the interface properties with the NiO/ZnO and the ZnNiO/ZnO.
Nonlinear Regression Models and Applications in Agricultural Research
Authors: Archontoulis Sotirios V. , Miguez Fernando E.
Published: May 2013

Nonlinear regression models are important tools because many crop and soil processes are better represented by nonlinear than linear models. Fitting nonlinear models is not a single‐step procedure but an involved process that requires careful examination of each individual step. Depending on the objective and the application domain, different priorities are set when fitting nonlinear models; these include obtaining acceptable parameter estimates and a good model fit while meeting standard assumptions of statistical models. We propose steps in fitting nonlinear models as described by a flow diagram and discuss each step separately providing examples and updates on procedures used. The following steps are considered: (i) choose candidate models, (ii) set starting values, (iii) fit models, (iv) check convergence and parameter estimates, (v) find the “best” model among competing models, (vi) check model assumptions (residual analysis), and (vii) calculate statistical descriptors and confidence intervals. The associated feedback mechanisms are also addressed (i.e., model variance homogeneity). In particular, we emphasize the first step (choose candidate models) by providing an extensive library of nonlinear functions (77 equations with the associated parameter meanings) and examples of typical applications in agriculture. We hope that this contribution will clarify some of the difficulties and confusion with the task of using nonlinear models.
Nitrogen Source and Rate Effects on Irrigated Corn Yields and Nitrogen‐Use Efficiency
Authors: Halvorson Ardell D. , Bartolo Michael E.
Published: May 2013

Nitrogen rate studies were conducted under furrow‐irrigated corn (Zea mays L.) production on a silty clay soil to compare granular urea with polymer‐coated urea (PCU) and stabilized urea (SU, contains urease and nitrification inhibitors) effects on corn yields, plant N uptake, and N use efficiency. Polymer‐coated urea had a yield advantage over urea 2 (continuous corn) of 3 yr at N rates below maximum yield, which resulted in greater economic returns with PCU (4–14%) at N rates from 168 to 280 kg N ha−1. The SU fertilizer had no yield or economic advantage over urea. Grain and stover yields and N uptake increased with increasing N rate for all N sources. Expressing grain yields from all N sources as a linear‐plateau function of N rate showed that yields were maximized at 14.3 Mg ha−1 at an N rate of 254 kg N ha−1 or available N level (soil NO3–N plus fertilizer N) of 295 kg N ha−1. Nitrogen recovery efficiency (RE) tended not to vary with N rate, with no differences between SU and urea but greater RE (19%) with PCU than urea under continuous corn. Fertilizer N use efficiency did not vary with N rate but was greater for PCU (36%) than for urea (32%) under continuous corn. In contrast to SU, PCU provided grain yield and potential economic advantages over urea under continuous corn production at N rates below those needed with urea for maximum grain yield.
Heritability and Genetic Relationships for Drought‐Related Traits in Peanut
Authors: Chen Charles Y. , Nuti Russell C. , Rowland Diane L. , Faircloth Wilson H. , Lamb Marshall C. , Harvey Ernest
Published: May 2013

Water‐use efficiency is often genetically correlated with specific leaf area (SLA) and leaf C isotopic composition (δ13C) in peanut (Arachis hypogaea L.). The objectives of this study were to examine the effects of environment, genotype, and genotype × environment interaction on SLA, δ13C, harvest index (HI), and yield and to estimate heritability and the genetic relationships. Fifteen genotypes were tested at two locations with different drought intensities for 2 yr. The additive main effects and multiplicative interaction analysis based on yield data divided eight environments (locations × treatments × years) into four clusters, which reflected a gradient in drought stress, indicating yield trait is a good indication of drought stress. The genotype Exp8‐12 was identified as a best drought tolerant germplasm across environments. Heritability estimates for HI (0.68 to 0.89) and δ13C (0.75 to 0.89) were higher than those for SLA (0.31 to 0.88) and yield (0.12 to 0.65). A positive but small genetic correlation coefficient (rg) (0.26) was found between HI and yield, and low to moderate rg (0.14 to 0.55) were observed between HI and SLA. A relative high negative genetic correlation rg (−0.81 to −0.57) was found between δ13C and yield. In theory, the high heritability and no G×E interaction for δ13C make it possible a surrogate that can be used to assess drought tolerance in peanut breeding.
Dry Matter, Carbon, and Nitrogen Accumulation of Four Great Plains Grasses
Authors: Muir J.P. , Lee A.E. , Lambert B.D. , Reilley J.L. , Naumann H.J. , Bow J. R.
Published: May 2013

Native North American warm‐season bunchgrasses have the potential to provide both forage and cellulosic bioenergy in drier regions of the southern Great Plains. Almost no information is available on the potential accumulations of many of these species under forage, bioenergy, or combined system harvests. Multiflower false rhodesgrass (MFR; Chloris pluriflora Fourn.), pink pappusgrass (PPG; Pappophorum bicolor Fourn.), shortspike windmill grass (SSWG; Chloris × subdolichostachya Müll. Berol. (pro sp.) [cucullata × verticillata]), and plains bristlegrass (PBG; Setaria vulpiseta Scribn. and Merr.) were harvested during 4 yr at Stephenville, TX, USA. Seedlings were transplanted into a Windthorst sandy loam soil fertilized in Year 1 with 0 or 67 kg N and P ha−1 yr−1 plus 67 kg N ha−1 yr−1 in the spring of Years 2 to 4. Fertilizer improved N and dry matter (DM) accumulations (P ≤ 0.05) except for SSWG and improved (P ≤ 0.05) accumulations of October regrowth following July harvest in greater rainfall years. Multiflower false rhodesgrass produced greater (P ≤ 0.05) accumulation the first year (up to 4.38 Mg ha−1) while PPG had the most consistent accumulation across years with variable precipitation. Results indicate that MFR and PPG bunchgrasses native to the North American Great Plains have potential for bioenergy or forage and bioenergy production systems.
Factors Affecting Foliar Nitrogen Uptake by Creeping Bentgrass
Authors: Henning S. W. , Mulvaney R. L. , Branham B. E.
Published: May 2013

Turfgrass managers frequently apply N as a foliar spray when low application rates are desired. This practice is believed to promote foliar N uptake that benefits turf; however, very little information is available concerning the quantity of N absorbed by turfgrass foliage or the effect of various spray parameters on foliar N uptake under field conditions. This research was conducted to evaluate fertilizer N uptake efficiency of foliarly applied 15N to creeping bentgrass [Agrostis stolonifera var. L. palustris (Huds.) Farw. ‘Pennlinks’] under field conditions. The effects of spray volume, N carrier, adjuvant addition, and tank mixing with commonly applied turf care products (e.g. chlorothalonil) on foliar N uptake were conducted to evaluate foliar uptake of fertilizer 15N by creeping bentgrass. From 6 to 34% of foliar‐applied N was taken up mostly within 2 h and completely by 4 to 6 h after fertilizer application. Uptake efficiency increased significantly when spray volume was decreased but was unaffected by N carrier, adjuvant addition, or tank mixing.
Nondegradative Extraction and Measurement of Uric Acid from Poultry Litter
Authors: Mowrer Jake , Kissel David E. , Cabrera Miguel , Hassan Sayed M.
Published: May 2013

Due to limited solubility of uric acid from poultry litter (PL), alkaline solutions are frequently used to extract uric acid from PL for measurement, but the high pH can cause oxidation of the analyte. Our objective was to compare 0.1 M sodium acetate, 0.025 M Li2CO3, and a NaOH/Na2PO4 buffer as a means of extracting uric acid from PL for analysis by high‐pressure liquid chromatography (HPLC). In laboratory experiments, extractant‐induced degradation of reagent uric acid proceeded at a rate of 80 g kg−1 d−1 in 0.025 M of Li2CO3 (pH 11.2) and a NaOH/Na2PO4 buffer (pH 12.4) compared with no degradation in sodium acetate over a 2‐d period. In extracted PL samples, the alkaline extractants were found to enhance the enzymatic oxidation of uric acid to completion in Li2CO3 and by 800 g kg−1 in a NaOH/Na2PO4 buffer over the same 2‐d period. Sodium acetate extraction resulted in minimal loss of analyte (30 g kg−1), possibly due to thermal inactivation of the responsible enzyme uricase. Stabilization of the dissolved uric acid extracted from PL samples allowed for the development of a very accurate measurement procedure by HPLC with ultraviolet (UV)–visible light spectrometer (VIS) detection at 290 nm. Our results suggest a reporting limit of 8.5 mg uric acid–N kg−1 of litter. Of the 118 PL samples that were analyzed in this study, uric acid‐, ammonium‐, and nitrate‐N concentrations accounted for an average of 9.4, 17.4, and 1.2%, respectively, of the total N present in PL.
Evaluation of surface water quality of the Buriganga River
Authors: Pramanik Biplob Kumar , Sarker Dipok Chandra
Published: May 2013

The Buriganga River receives partially treated sewage effluent, sewage polluted surface runoff and untreated industrial effluent from Dhaka city. This study examines the present status of surface water quality of Buriganga River at different locations in Dhaka City. The values of dissolved oxygen (DO), pH, colour, total coliforms, turbidity and ammonia were always very high over the year 2011. The maximum level of DO concentration was 3.4 mg/l, which is below the acceptable limit for surface water. Results also showed that high turbidity and low colour values were found in the rainy season while low turbidity and high colour values were found in the dry season. Moreover, the values of all parameters were always high at Buri 2 (Hazaribagh) because of the proximity of industrial sites. It is important to improve the water quality of the Buriganga River by protecting it from pollution.
Reuse of wastewater for irrigating tomato plants (Lycopersicon esculentum L.) through silicon supplementation
Authors: Ashraf Muhammad , Imtiaz Muhammad , Abid Muhammad , Afzal Muhammad , Shahzad Sher Muhammad
Published: May 2013

When untreated wastewater is used for the irrigation of crops, dissolved heavy metals may impose negative impacts on plant growth and pose health risks. However, silicon nutrition may improve plant tolerance to metal toxicity through external and internal plant mechanisms. This work aims at investigating the effects of silicon on copper, nickel, manganese, cadmium and zinc detoxification in tomato plants. The plants were grown for 50 days by irrigating with tap water and wastewater and having silicon added at 25, 50 and 75 mg kg–1 soil. Results revealed that wastewater irrigation caused an increase of 277–480% in copper, 178–233% nickel, 355–680% manganese, 500–900% cadmium and 117–337% zinc in tomato plants compared to tap water irrigation. The root:stem metal ratios showed that a major portion of absorbed metals was translocated to aerial plant parts when wastewater was applied without silicon. However, silicon supplementation precipitated the metals in soil and influenced their uptake and partitioning within the plant body. The shoot dry matter of tomato plants was negatively correlated with wastewater-induced stem metal concentrations. This study suggests that silicon-assisted metal tolerance of tomato plants was attributed to metal precipitation in soil, complexation in roots and, hence, reduction in their translocation to stems and leaves.
Evidence for Insisting on Cognitive Conflict Tasks: Impact on Accounting Majors in Upper-Level Courses
Authors: Sargent Carol Springer , Borthick A. Faye
Published: May 2013

Springer and Borthick (2004a) designed cognitive conflict tasks in sophomore accounting to develop critical thinking. While prior work showed that students completing critical thinking courses had stronger content knowledge (Springer and Borthick 2007), it provided no evidence that these experiences would improve performance in courses with new content areas. This study extends the prior work by providing evidence of far transfer, the kind that would be expected if critical thinking were developed during the sophomore tasks. In this study, students with cognitive conflict task experience in sophomore accounting performed better than those with traditional sophomore accounting experience, in both readings-only and problem-based junior-level courses. In addition, the graduation GPAs of students with cognitive task experience increased more between the junior year and graduation than those of students without these tasks. An interaction between GPA and sophomore learning experience showed stronger effects for lower-achieving students, consistent with improved critical thinking.