bluuebunny/crossref_metadata_2025 huggingface dataset:
Sperm Storage and Sperm Competition Across Ovarian Cycles in the Dragon Lizard, Ctenophorus fordi
Authors: ULLER TOBIAS , SCHWARTZ TONIA , KOGLIN TROY , OLSSON MATS
Published: June 2013

Female sperm storage can influence male reproductive success and may favour males that produce sperm that remain viable across several ovarian cycles. Here we show that sperm are viable in the female reproductive tract across ovarian cycles in the mallee dragon, Ctenophorus fordi. Based on experimental mating trials, we show that stored sperm were generally less likely to fertilize eggs than recently inseminated sperm. The fertilization success of stored sperm increased with male body size relative to rivals. This may be due to differences in ejaculate volume or sperm number transferred by males of different sizes. However, there was no evidence that copulation time, which is correlated with ejaculate volume, contributed to fertilization success. We suggest that sperm storage across ovarian cycles may be common in small, multi‐clutched lizards and that its impact on selection on male phenotypes could contribute to the evolution of lizard mating systems. J. Exp. Zool. 319A: 404–408, 2013. © 2013 Wiley Periodicals, Inc.
Effects of Growth Hormone (GH) Transgene and Nutrition on Growth and Bone Development in Common Carp
Authors: Zhu Tingbing , Zhang Tanglin , Wang Yaping , Chen Yushun , Hu Wei , Zhu Zuoyan
Published: June 2013

Limited information is available on effects of growth hormone transgene and nutrition on growth and development of aquatic animals. Here, we present a study to test these effects with growth‐enhanced transgenic common carp under two nutritional conditions or feeding rations (i.e., 5% and 10% of fish body weight per day). Compared with the nontransgenic fish, the growth rates of the transgenic fish increased significantly in both feeding rations. The shape of the pharyngeal bone was similar among treatments, but the transgenic fish had relatively smaller and lighter pharyngeal bone compared with the nontransgenic fish. Calcium content of the pharyngeal bone of the transgenic fish was significantly lower than that of the nontransgenic fish. Feeding ration also affected growth rate but less of an effect on bone development. By manipulating intrinsic growth and controlling for both environment (e.g., feeding ration) and genetic background or genotype (e.g., transgenic or not), this study provides empirical evidence that the genotype has a stronger effect than the environment on pharyngeal bone development. The pharyngeal bone strength could be reduced by decreased calcium content and calcification in the transgenic carp. J. Exp. Zool. 319A: 451–460, 2013. © 2013 Wiley Periodicals, Inc.
Reduced proton and alpha particle precipitations at Mars during solar wind pressure pulses: Mars Express results
Authors: Diéval C. , Stenberg G. , Nilsson H. , Edberg N. J. T. , Barabash S.
Published: June 2013

We performed a statistical study of downward moving protons and alpha particles of ~keV energy (assumed to be of solar wind origin) inside the Martian induced magnetosphere from July 2006 to July 2010. Ion and electron data are from the Analyzer of Space Plasma and Energetic Atoms (ASPERA‐3) package on board Mars Express. We investigated the solar wind ion entry into the ionosphere, excluding intervals of low‐altitude magnetosheath encounters. The study compares periods of quiet solar wind conditions and periods of solar wind pressure pulses, including interplanetary coronal mass ejections and corotating interaction regions. The solar wind ion precipitation appears localized and/or intermittent, consistent with previous measurements. Precipitation events are less frequent, and the precipitating fluxes do not increase during pressure pulse encounters. During pressure pulses, the occurrence frequency of observed proton precipitation events is reduced by a factor of ~3, and for He2+ events the occurrence frequency is reduced by a factor of ~2. One explanation is that during pressure pulse periods, the mass loading of the solar wind plasma increases due to a deeper penetration of the interplanetary magnetic flux tubes into the ionosphere. The associated decrease of the solar wind speed thus increases the pileup of the interplanetary magnetic field on the dayside of the planet. The magnetic barrier becomes thicker in terms of solar wind ion gyroradii, causing the observed reduction of H+/He2+ precipitations.
Spontaneous hot flow anomalies at quasi‐parallel shocks: 1. Observations
Authors: Zhang H. , Sibeck D. G. , Zong Q.‐G. , Omidi N. , Turner D. , Clausen L. B. N.
Published: June 2013

We present Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations of a “Spontaneous Hot Flow Anomaly” (SHFA) upstream from the prenoon bow shock at 0431 UT on 12 August 2007. Although the SHFA exhibited the greatly heated and deflected solar wind plasmas used to identify hot flow anomalies (HFAs), it did not result from the standard mechanism invoked for the formation of HFAs, namely the interaction of an interplanetary magnetic field (IMF) discontinuity with the bow shock. We employ THEMIS A, B, C, and D observations to describe the evolution of the event from a proto‐SHFA exhibiting regions of depressed magnetic field strength and density but little evidence for plasma heating or flow deflection, to a well‐developed SHFA further downstream. These observations show that SHFA can be generated without the presence of an IMF discontinuity and are therefore a new category of HFAs.
Creation and tidal advection of a cold salinity front in Storfjorden: 2. Supercooling induced by turbulent mixing of cold water
Authors: McPhee Miles G. , Skogseth Ragnheid , Nilsen Frank , Smedsrud Lars H.
Published: June 2013

Measurements near the edge of fast ice in Freemansundet, Svalbard, reveal mixing processes associated with tidal advection of a sharp front in salinity, including possible supercooling induced by double diffusion in a fully turbulent water column. The front translated back and forth with the semidiurnal tide between an area of mobile (drifting) ice in Storfjorden proper, and the narrow sound covered by fast ice. Water on each side of the front was near its salinity‐determined freezing temperature. Instruments deployed about 400 m into the sound from the fast ice edge measured current, temperature, conductivity, and turbulence quantities through several tidal cycles. Turbulence data illustrate that as the steep horizontal salinity (density) gradient advected past the measurement site, vertical shear near the fast‐ice base induced marked flood/ebb asymmetry in turbulent mixing. As fresher water entered the sound on the flood phase, inward transport of denser water near the upper boundary was retarded, leading to statically unstable conditions and enhanced turbulence. The opposite occurred during ebb tide, as denser water underran lighter. Transient episodes of supercooling accompanied frontal passage on both flood and ebb phases. The most likely explanation for a zone of supercooled water within the strongly mixed frontal region is that during mixing of fresher, slightly warmer (but still at freezing) water from outside with saltier, colder water in the sound, the former constituent lost heat faster than gaining salt. This interpretation (differing turbulent diffusivities for heat and salt) challenges strict application of Reynolds analogy for highly turbulent shear flow.
Land‐lake breezes at low latitudes: The case of Tonle Sap Lake in Cambodia
Authors: Tsujimoto Kumiko , Koike Toshio
Published: June 2013

Tonle Sap Lake is the largest freshwater lake in Southeast Asia. During the postmonsoon season, a small linear cloud system has been observed over this lake in early morning, while the sky above the surrounding land is clear. Although this cloud system is apparently generated by land breezes, previous studies on land‐lake (sea) circulation have suggested that environmental factors at low latitudes inhibit development of nocturnal land breezes. In this study, we investigate the mechanism of these early morning clouds through numerical simulation. The simulations show a linear updraft system over the lake, forming along the southwest lakeshore around 22:00 and moving northeast to the middle of the lake. The heavier air mass from the land meets the extraordinarily warm and humid air mass over the lake, triggering updrafts under the conditionally convective instability. The characteristic high surface water temperature was favorable for generation of the land breeze and updraft systems. That high surface water temperature of the lake is produced by the tropical climate along with efficient energy absorption because of the shallowness of the water body. This unique feature can generate a clear nocturnal land breeze circulation accompanying a migrating updraft system over the lake despite its low latitude.
Multirater and Gender Differences in the Measurement of Political Skill in Organizations
Authors: Westbrook Thomas S. , Veale James R. , Karnes Roger E.
Published: June 2013

Organizational political skill is an essential component of a leader's success. The purpose of the current study was to ascertain whether differences existed in how individuals rated themselves and were rated by others on 13 political skills using the Brandon Partners and Seldman Learning Organizational Savvy Multi‐Rater Assessment. Over 4,500 individuals completed an online self‐rater assessment to test the reliability and validity of the instrument. A sample of 131 individuals with 1,056 observer ratings completed an online multirater assessment to address the research questions. The dependent variables were the 13 political skill set average scores and the independent variables included gender and rater group. Significant rater group differences in multirater assessment of political acumen were found in all skill sets. The greatest difference was between the self‐ratings, always the lowest, and the ratings of the four rater groups. No significant gender differences in self‐assessment of organizational political skill were found in the 13 skill sets. Significant gender differences in ratings by others were found with females scoring higher than males in two areas. The findings contribute to our understanding of gender differences regarding the perception of political skill. Organizations can use this knowledge in educational programs to elevate leader performance.
Wolf in Sheep's Clothing: Harmful Leadership with a Moral Façade
Authors: Mohr James M.
Published: June 2013

The current qualitative study used narrative inquiry to explore white supremacist leadership and how it aligns with and differs from transformational, servant, and charismatic leadership theories. By examining the concepts and examples of leadership within the white supremacist movement, an image of harmful leadership begins to develop. These leaders were found to use leadership strategies such as creating purpose, community building, follower focus and meaning making, empowerment and motivation, and trust and respect to gain followers. These strategies were combined with detrimental approaches to leadership that included pursuing and abusing power, developing a sense of self‐importance, using fear, and having a sense of isolation that contributed to a harmful leadership style. Harmful leadership and its implications for leaders and followers in more mainstream organizations are explored.
Anthracene‐Containing Wide‐Band‐Gap Conjugated Polymers for High‐Open‐Circuit‐Voltage Polymer Solar Cells
Authors: Gong Xue , Li Cuihong , Lu Zhen , Li Guangwu , Mei Qiang , Fang Tao , Bo Zhishan
Published: June 2013

The synthesis, characterization, and photophysical and photovoltaic properties of two anthracene‐containing wide‐band‐gap donor and acceptor (D–A) alternating conjugated polymers (P1 and P2) are described. These two polymers absorb in the range of 300–600 nm with a band gap of about 2.12 eV. Polymer solar cells with P1:PC71BM as the active layer demonstrate a power conversion efficiency (PCE) of 2.23% with a high Voc of 0.96 V, a Jsc of 4.4 mA cm−2, and a comparable fill factor (FF) of 0.53 under simulated solar illumination of AM 1.5 G (100 mW cm−2). In addition, P2:PC71BM blend‐based solar cells exhibit a PCE of 1.42% with a comparable Voc of 0.89 V, a Jsc of 3.0 mA cm−2, and an FF of 0.53.

magnified image
Design of Experiments for Reactivity Ratio Estimation in Multicomponent Polymerizations Using the Error‐In‐Variables Approach
Authors: Kazemi Niousha , Duever Thomas A. , Penlidis Alexander
Published: June 2013

Model‐based design of experiments using the error‐in‐variables model (EVM) is explored. The fundamental differences between DOE in the traditional nonlinear regression versus the EVM context are discussed, and it is pointed out that for cases where there are errors in all variables, using the EVM design criterion is the only appropriate approach. In addition, the implementation of the EVM design criterion and its characteristics for both initial and sequential design schemes are discussed. The main application is the implementation of the EVM criterion to design optimal trials for reliable estimating reactivity ratios for typical copolymerization systems, along with prescriptions for the practitioner.
Alpha‐synuclein gene duplication: Marked intrafamilial variability in two novel pedigrees
Authors: Elia Antonio E. , Petrucci Simona , Fasano Alfonso , Guidi Marco , Valbonesi Stefano , Bernardini Laura , Consoli Federica , Ferraris Alessandro , Albanese Alberto , Valente Enza Maria
Published: June 2013

Background

Multiplications of the SNCA gene that encodes alpha‐synuclein are a rare cause of autosomal dominant Parkinson's disease (PD).

Methods

Here, we describe 2 novel families in which there is autosomal dominant PD associated with SNCA duplication, and we compare the clinical features of all known patients carrying 3 or 4 SNCA copies.

Results

Affected members in family A presented with early onset PD that was variably associated with nonmotor features, such as dysautonomia, cognitive deficits, and psychiatric disturbances. In family B, the clinical presentation ranged from early onset PD‐dementia with psychiatric disturbances to late onset PD with mild cognitive impairment.

Conclusions

The presence of 4 SNCA copies is associated with a rich phenotype, characterized by earlier onset of motor and nonmotor features compared with patients who bear 3 SNCA copies. The clinical spectrum associated with SNCA duplications is wide, even within a single family, suggesting a role for as yet unidentified genetic or environmental modifiers. © 2013 Movement Disorder Society
G Protein‐Coupled Estrogen Receptor (GPER) Agonist Dual Binding Mode Analyses Toward Understanding of Its Activation Mechanism: A Comparative Homology Modeling Approach
Authors: Arnatt Christopher K. , Zhang Yan
Published: June 2013

G protein‐coupled estrogen receptor (GPER) has been shown to be important in several disease states such as estrogen sensitive cancers. While several selective ligands have been identified for the receptor, little is known about how they interact with GPER and how their structures influence their activity. Specifically, within one series of ligands, whose structure varied only at one position, the replacement of a hydrogen atom with an acetyl group changed a potent antagonist into a potent agonist. In this study, two GPER homology models were constructed based on the X‐ray crystal structures of both the active and inactive β2‐adrenergic receptors (β2AR) in an effort to characterize the differences of binding modes between agonists and antagonists to the receptor, and to understand their activity in relation to their structures. The knowledge attained in this study is expected to provide valuable information on GPER ligands structure activity relationship to benefit future rational design of potent agonists and antagonists of the receptor for potential therapeutic applications.
Computational Insights into the Mechanism of Inhibition of OASS‐A by a Small Molecule Inhibitor
Authors: Bruno Agostino , Amori Laura , Costantino Gabriele
Published: June 2013

O‐Acetylserine sulfhydrylase (isoform A, OASS‐A) is a PLP‐dependent enzyme involved in the last step of cysteine biosynthesis in many pathogens. Many microorganisms use cysteine as the main building block for sulfur‐containing antioxidants, and cysteine depletion in several pathogens resulted in a reduced antibiotic resistance, thus leading to the identification of OASS as novel suitable molecular targets to overcome antimicrobial resistances. The precise molecular mechanism of OASS‐A inhibition by small peptides or by small molecule inhibitors is still unclear. To shed more lights on the structural basis underlying the inhibition mechanism for OASS, we engaged ourselves in studying the dynamic properties of this enzyme. In this paper, we describe a computational study involving unbiased MD simulations of OASS‐A from Haemophilus influenzae (HiOASS) in its inhibitor free, PLP‐bound form, and in complex with a pentapeptide inhibitor and with UPAR40, a small molecule which we have recently reported as a potent OASS‐A inhibitors. We proposed that UPAR40 inhibits HiOASS‐A through the stabilization of a closed conformation. Moreover, preliminary docking studies and sequence analysis allow us to speculate about the non‐specificity of UPAR40 toward a particular OASS enzyme species or isoforms.
Review of recent data on the metabolism, biological effects, and toxicity of resveratrol in humans
Authors: Cottart Charles‐Henry , Nivet‐Antoine Valérie , Beaudeux Jean‐Louis
Published: June 2013

Several recently published clinical trials have extended our knowledge on the use of resveratrol (RVT) to treat several human pathological and metabolic disorders. Herein, we present insights into the metabolism, biological effects, and toxicity of RVT in humans. Recent data show that RVT exhibits antioxidant and anti‐inflammatory activities. It can also improve glucose and lipid metabolism, it acts on cardiovascular parameters, and can modify some pathways involved in carcinogenesis. However, these effects are mostly tiny and the results are sometimes controversial as they depend on the protocols (i.e. dose, form of administration, patients’ characteristics, adjuvant therapy, etc.). Toxicological data confirm that RVT is well tolerated. Any adverse effects (mainly concerning the abdomen), at doses of ≥0.5 g/day for long periods, remain moderate and reversible. Nevertheless, the efficacy and safety of RVT need to be further investigated.
Arginine and nitric oxide synthase: Regulatory mechanisms and cardiovascular aspects
Authors: Lorin Julie , Zeller Marianne , Guilland Jean‐Claude , Cottin Yves , Vergely Catherine , Rochette Luc
Published: June 2013

l‐Arginine (l‐Arg) is a conditionally essential amino acid in the human diet. The most common dietary sources of l‐Arg are meat, poultry and fish. l‐Arg is the precursor for the synthesis of nitric oxide (NO); a key signaling molecule via NO synthase (NOS). Endogenous NOS inhibitors such as asymmetric‐dimethyl‐l‐Arg inhibit NO synthesis in vivo by competing with l‐Arg at the active site of NOS. In addition, NOS possesses the ability to be “uncoupled” to produce superoxide anion instead of NO. Reduced NO bioavailability may play an essential role in cardiovascular pathologies and metabolic diseases. l‐Arg deficiency syndromes in humans involve endothelial inflammation and immune dysfunctions. Exogenous administration of l‐Arg restores NO bioavailability, but it has not been possible to demonstrate, that l‐Arg supplementation improved endothelial function in cardiovascular disease such as heart failure or hypertension. l‐Arg supplementation may be a novel therapy for obesity and metabolic syndrome. The utility of l‐Arg supplementation in the treatment of l‐Arg deficiency syndromes remains to be established. Clinical trials need to continue to determine the optimal concentrations and combinations of l‐Arg, with other protective compounds such as tetrahydrobiopterin (BH4), and antioxidants to combat oxidative stress that drives down NO production in humans.
Weight loss after bariatric surgery in morbidly obese adolescents with MC4R mutations
Authors: Censani Marisa , Conroy Rushika , Deng Liyong , Oberfield Sharon E. , McMahon Donald J. , Zitsman Jeffrey L. , Leibel Rudy L. , Chung Wendy K. , Fennoy Ilene
Published: June 2013

Objective

To determine the frequency of Melanocortin 4 Receptor (MC4R) mutations in morbidly obese adolescents undergoing bariatric surgery and compare weight loss outcomes in patients with and without mutations.

Design and Methods

In this prospective cohort study, 135 adolescent patients evaluated for bariatric surgery were screened for MC4R mutations; 56 had 12‐month postoperative data available for analysis.

Results

MC4R mutations were detected in five of the 135 patients (3.7%); four underwent restrictive bariatric surgery. For the three patients with gastric banding, percent excess weight loss (%EWL) postoperatively was 36.0% at 5 years in one, 47% at 4 years in the second, and 85% at 1 year in the third. For the patient with gastric sleeve resection, %EWL of 96% was attained at 1 year postoperatively. The four MC4R cases had a higher, although nonsignificant, %EWL compared to 52 nonmatched controls at 12 months postoperatively (48.6% vs. 23.4%; P < 0.37). When matched by age, sex, and race to 14 controls, there was no significant difference in %EWL (P < 0.31), BMI change (P < 0.27), or absolute weight loss (P < 0.20).

Conclusion

The frequency of MC4R mutations is similar to prior studies, with affected patients showing beneficial weight loss outcomes.
Anticoagulation Control with Daily Low‐Dose Vitamin K to Reduce Clinically Adverse Outcomes and International Normalized Ratio Variability: A Systematic Review and Meta‐Analysis
Authors: Lam Jason , Schulman Sam , Witt Daniel M. , Vandvik Per Olav , Qayyum Fareeha , Holbrook Anne M.
Published: June 2013

Study Objectives

Difficulties managing warfarin therapy have led to speculation that daily supplementation with a low dose of vitamin K might improve anticoagulation control and clinical outcomes. Thus we sought to review the available medical literature systematically examining the effectiveness of low‐dose vitamin K supplementation for the reduction of clinically relevant adverse events due to vitamin K antagonist (VKA) use and for stabilization of the international normalized ratio (INR).

Design

We searched the Medline and Embase databases, the Cochrane Library, International Pharmaceutical Abstracts, and the U.S. National Institutes of Health clinical trials registry for randomized controlled trials of vitamin K supplementation versus placebo in patients receiving a VKA. We evaluated the outcomes of hemorrhage, thromboembolic events, and percentage of time in therapeutic range (TTR) of INRs by using the Grading of Recommendations Assessment, Development and Evaluation system for rating quality of evidence in the abstracted studies.

Setting

All randomized controlled trials studies published between 1970 and August 2012 which fitted our search strategy.

Patients

Patients over the age of 18 years on VKA therapy.

Results

Of the 624 studies we identified and screened, three studies (626 patients) were included in the meta‐analysis. Most of the patients had a satisfactory TTR at baseline. We found low‐quality evidence—downgraded for imprecision and risk of bias (i.e., limitation in study design and/or execution)—of no effect of vitamin K use (100 to 200 μg) on hemorrhagic events (relative risk [RR] 3.2, 95% confidence interval [CI] 0.2–64.2) and thromboembolic events (RR 2.2, 95% CI 0.1–47.5) and a significant but clinically unimportant effect on TTR with an absolute increase of 3.5% (95% CI 1.1–6.0).

Conclusion

This meta‐analysis, despite the few studies and overall low quality, suggests no beneficial role of low‐dose (100 to 200 μg) vitamin K supplementation on the reduction of clinically relevant adverse events in patients taking VKAs, despite a small improvement of the TTR. Data were insufficient, however, from patients with unstable INRs.
Single‐Dose and Multiple‐Dose Pharmacokinetics and Dose Proportionality of Intravenous and Intramuscular HPβCD‐Diclofenac (Dyloject) Compared with Other Diclofenac Formulations
Authors: Mermelstein Fred , Hamilton Douglas A. , Wright Curtis , Lacouture Peter G. , Ramaiya Atulkumar , Carr Daniel B.
Published: June 2013

Study Objective

To evaluate single‐ and repeated‐dose pharmacokinetics (PK) and dose proportionality of hydroxypropyl‐β‐cyclodextrin (HPβCD)‐diclofenac compared with Voltarol after intravenous (IV) and intramuscular (IM) administration.

Design

Study 1: Single‐dose randomized four‐way crossover study. Study 2: Multiple‐dose randomized three‐way crossover study.

Setting

Clinical research center.

Subjects

Healthy adult volunteers.

Intervention

Study 1: Subjects received HPβCD‐diclofenac and Voltarol, IV and IM, with a 5‐day washout between treatment periods. Study 2: Subjects received two doses of IV HPβCD‐diclofenac and oral Cataflam once every 6 hours for four doses with a 48‐hour washout period between treatment periods.

Measurements and Main Results

Study 1: IV HPβCD‐diclofenac had a higher peak plasma concentration (Cmax) and earlier time to reach maximum plasma concentration (Tmax), but equivalent plasma exposure (area under the curve from time zero to t [AUC0–t]) to IV Voltarol. The geometric mean ratio of HPβCD‐diclofenac (IV) to Voltarol (IV) for AUC0–t was 106.27%. The geometric mean ratio of HPβCD‐diclofenac (IM) to Voltarol (IM) for AUC0–t was 110.91%. The geometric mean ratio of HPβCD‐diclofenac (IV) to HPβCD‐diclofenac (IM) for AUC0–t was 101.25%. The geometric mean ratio of HPβCD‐diclofenac (IM) to Voltarol (IV) for AUC0–t was 104.96%. Study 2: Cmax for diclofenac was 2904 and 6031 ng/ml after the first IV dose of 18.75 and 37.5 mg HPβCD‐diclofenac, respectively, and was 3090 and 5617 ng/ml after the fourth dose, indicating no accumulation. Plasma exposures to 18.75 mg (866 ng·hour/ml) and 37.5 mg (1843 ng·hour/ml) IV HPβCD‐diclofenac bracketed that of oral Cataflam 50 mg (1473 ng·hour/ml).

Conclusions

Study 1: Bioavailability in terms of AUC after IV administration was equivalent for HPβCD‐diclofenac compared with Voltarol and after IM administration of HPβCD‐diclofenac and Voltarol. Bioavailability in terms of AUC after IM administration of HPβCD‐diclofenac was equivalent to IV administration of HPβCD‐diclofenac and IV administration of Voltarol. Study 2: HPβCD‐diclofenac showed dose proportionality after single‐ and multiple‐dose administration and no accumulation of HPβCD‐diclofenac. HPβCD‐diclofenac was safe and well tolerated following IV and IM administration.
Assessment of Warfarin Dosing Requirements After Bariatric Surgery in Patients Requiring Long‐Term Warfarin Therapy
Authors: Irwin Adriane N. , McCool Kathleen H. , Delate Thomas , Witt Daniel M.
Published: June 2013

Study Objective

To quantify the change in weekly warfarin dose after bariatric surgery in patients requiring long‐term warfarin therapy.

Design

Retrospective matched‐cohort study.

Setting

Anticoagulation management service in an integrated health care delivery system.

Patients

Patients receiving long‐term warfarin anticoagulation who underwent bariatric surgery between January 1, 1996, and December 31, 2010 (27 patients), were matched by date of surgery (± 2 years), age (± 5 years), and target international normalized ratio (INR) range to patients receiving long‐term anticoagulation therapy who underwent other abdominal surgical procedures: cholecystectomy or endoscopic retrograde cholangiopancreatography (59 patients [control group]).

Measurement and Main Results

The main end point was change in postoperative warfarin dose from baseline (preoperative dose), measured at weekly postoperative intervals from weeks 1 to 8 and again at months 3 and 6. After surgery, patients in the bariatric surgery group had statistically significant decreases in weekly warfarin doses compared with preoperative dose at all postoperative time points (week 1 dose vs preoperative dose, p<0.01; doses at all other time points vs preoperative dose, p<0.001), except at 6 months (p>0.05). No statistically significant decreases in warfarin dose were detected at any postoperative time points in the control group.

Twenty patients (74.1%) in the bariatric surgery group experienced a 20% or more decrease in weekly warfarin dose compared with 19 patients (32.2%) in the control group (p=0.004). No significant differences in warfarin‐related adverse events were noted between groups.

Conclusion

Weekly warfarin doses decreased in the immediate postoperative period in anticoagulated patients after bariatric surgery but returned to their preoperative doses after approximately 6 months. A similar pattern was not observed in patients in the control group who underwent other types of abdominal surgery. Compared with preoperative anticoagulation control, this resulted in reduced anticoagulation control despite close INR monitoring. If a causal relationship between bariatric surgery and warfarin sensitivity is established in future research, developing and validating a postbariatric surgery warfarin‐dosing algorithm would be valuable.
Development of Acneiform Rash Does Not Predict Response to Lapatinib Treatment in Patients with Breast Cancer
Authors: Parma Jennifer , Pavlick Anne , Schiff Rachel , Osborne C. Kent , Chang Jenny C. , Rimawi Mothaffar , Trivedi Meghana V.
Published: June 2013

Study Objective

To determine if development of acneiform rash is a predictor of objective response rate with lapatinib.

Design

Subanalysis of data from a prospective, phase II study.

Setting

Academic breast care clinic.

Patients

Forty‐nine treatment‐naïve patients with human epidermal growth factor receptor‐2 (HER2)‐positive locally advanced breast cancer, who were treated with neoadjuvant lapatinib monotherapy for 6 weeks; 47 patients were included in the final analysis.

Measurements and Main Results

Of the 49 patients enrolled, 33 (67%) developed a rash of any type, and 26 (55%) had acneiform rash. Of the 26 evaluable patients with acneiform rash (55%), 19 (73%) responded to lapatinib and 7 (27%) did not. Of the 21 evaluable patients without acneiform rash, 11 (67%) responded to treatment and 7 (33%) did not. Thus, no association was found between the occurrence of acneiform rash and response to lapatinib monotherapy.

Conclusion

This study does not support the development of the acneiform rash as a predictor of clinical efficacy of lapatinib in the treatment of breast cancer.
Nanofabrication with metallopolymers ‐ recent developments and future perspectives
Authors: Ramanathan Muruganathan , Darling Seth B.
Published: June 2013

Synthetic polymers containing metals and metal centers have experienced rapid growth in the last two decades. Metal‐containing polymers have an unprecedented role to play in modern high‐tech applications including nanomanufacturing, sensing, separation and catalysis. Advancement in synthetic strategies for macromolecules has enabled the synthesis of novel, exotic and use‐inspired metallopolymers. Using state‐of‐the‐art design strategies, it is now possible to perform targeted synthesis of macromolecules with varied complexity that contain a range of metal centers either in the backbone or in the side chains of the organic moiety. The presence of an inorganic element (metals and metal centers) in organic moieties has led to a number of new physicochemical properties while implementing novel functionality to the polymer matrix. This review covers nanotechnology influenced by distinctive features of metal‐containing macromolecular systems, particularly in developing flexible, functional materials. © 2013 Society of Chemical Industry
Does the 2,6‐didehydropyridinium cation exist?
Authors: Jankiewicz Bartłomiej J. , Vinueza Nelson R. , Kirkpatrick Lindsey M. , Gallardo Vanessa A. , Li Guannan , Nash John J. , Kenttämaa Hilkka I.
Published: June 2013

Reactive intermediates are key species involved in many chemical and biochemical processes. For example, carbon‐centered aromatic σ,σ‐biradicals formed in biological systems from naturally occurring enediyne antitumor antibiotics are responsible for the irreversible cleavage of double‐stranded DNA caused by these prodrugs. However, because of their high reactivity, it is very difficult or impossible to isolate and investigate these biradicals. The aromatic σ,σ‐biradical, 2,6‐didehydropyridine, has been speculated for many years to be formed in certain organic reactions; however, no definitive proof of its generation has been obtained. We report here the successful generation of protonated 2,6‐didehydropyridine and the examination of its chemical properties in the gas phase by using a Fourier transform ion cyclotron resonance mass spectrometer. The results suggest that a mixture of singlet (ground) state and triplet (excited) state 2,6‐didehydropyridinium cations was generated. The two different states show qualitatively different reactivity, with the triplet state showing greater Brønsted acidity than that of the singlet state. The triplet state also shows much greater radical reactivity than that of the singlet state, as expected because of the coupling of the nonbonding electrons in the singlet state. Copyright © 2013 John Wiley & Sons, Ltd.
Synthesis of linear and hyperbranched sugar‐grafted polysiloxanes using N‐hydroxysuccinimide‐activated esters
Authors: Moukarzel Waêl , Marty Jean‐Daniel , Appelhans Dietmar , Mauzac Monique , Fitremann Juliette
Published: June 2013

A straightforward method for the preparation of polysiloxanes grafted with carbohydrate side groups is described. Two kinds of backbones have been functionalized, namely one‐dimensional, linear polysiloxanes, and hyperbranched poly(siloxysilane)s based on cyclotetrasiloxanes. The method enables us to keep a good integrity of the polysiloxane backbone. The introduction of intermediate activated esters as side groups on the polysiloxane backbone ensures a complete homogeneity of the reaction medium during sugar grafting in dimethyl sulfoxide, and consequently an easy grafting with the unprotected amino sugar. Solubility of the resulting polysiloxanes has been tested in various solvents. The sugar‐grafted polysiloxanes are good candidates for applications such as silicone formulations, hydrophilic silicone elastomers, interactions with metallic nanoparticles, and suspension stabilization, or as starting point for the design of more complex polysiloxanes for molecular recognition. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3607–3618
Cyclic and linear poly(ferrocenylene alkylene)s synthesized from addition‐condensation polymerization of ferrocene with aldehydes
Authors: Suzaki Yuji , Yoshigoe Yusuke , Osakada Kohtaro
Published: June 2013

Oligo‐ and poly(ferrocenylene alkylene)s, [Fe(C5H5‐x)(C5H5‐y)CHR]n (x = y = 1 or x = 2, y = 0; R = alkyl, aryl), were synthesized by Lewis acid‐promoted addition‐condensation polymerization of ferrocene with aldehydes. The reaction of alkyl aldehydes, such as n‐hept‐CHO, EtCHO and nBuCHO, with ferrocene yields a mixture of the cyclic and linear poly(ferrocenylene alkylene)s, while aryl aldehyde, such as C6F5CHO, CF3C6H4‐4‐CHO and MeC6H4‐4‐CHO, forms the linear polymers exclusively. The linear polymer has terminal Fe(C5H4)(C5H5) and CH2Aryl groups, which are characterized by high resolution mass spectroscopy. Results of addition‐condensation polymerization of ferrocenemethanol catalyzed by BF3 indicate that the propagating polymer of the above addition‐condensation polymerization contains terminal 1‐hydroxyalkyl‐ferrocenylene group, Fe(C5H4)[C5H4{CH(OH)R}]. The trimer prepared from ferrocene and paraformaldehyde dimethylacetal contains 1,1′‐, 1,2‐, and 1,3‐ferrocenylene units, suggesting that the polymers obtained from alkyl and aryl aldehydes are also composed of these structural units. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3627–3635
Characterization of catechol‐containing natural thermosetting polymer “urushiol” thin film
Authors: Watanabe Hirohmi , Fujimoto Aya , Takahara Atsushi
Published: June 2013

Urushi (oriental lacquer) is made from the sap of Rhus vernicifera and consists mainly of the catechol derivative urushiol. Thermal curing of urushiol, unlike other catechol derivatives, is possible because of the unsaturated double bonds in the long hydrocarbon side chain. We described here a simple, efficient method to produce a thermally cross‐linked urushi thin film using iron(II) acetate as the additive. The cured thin films showed robust, flexible feature as confirmed by strain‐induced elastic buckling instability for mechanical measurements (SIEBIMM) and bulging experiments. In contrast, a thin film of poly(dopamine) that is a typical catechol derivative without long hydrocarbon side chain showed brittleness. The long hydrocarbon side chain of urushiol plays an important role for both thermal processability and superior mechanical properties of the material. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3688–3692
Poly(lactic acid) composites with poly(lactic acid)‐modified carbon nanotubes
Authors: Novais Rui M. , Simon Frank , Pötschke Petra , Villmow Tobias , Covas José A. , Paiva Maria C.
Published: June 2013

This work reports the study of the effect of chemical functionalization of carbon nanotubes on their dispersion in poly(lactic acid). The nanotubes were functionalized by the 1,3‐dipolar cycloaddition reaction, generating pyrrolidine groups at the nanotube surface. Further reaction of the pyrrolidine groups with poly(lactic acid) was studied in solution and in the polymer melt. The former involved refluxing the nanotubes in a dimethylformamide/polymer solution; the latter was carried out by direct melt mixing in a microcompounder. The carbon nanotubes collected after each process were characterized by thermogravimetry and by X‐ray photoelectron spectroscopy, showing evidence of polymer bonded to the nanotube surface only when the reaction was carried out in the polymer melt. The composites with polymer modified nanotubes present smaller average agglomerate area and a narrower agglomerate area distribution. In addition, they show improved tensile properties at low CNT concentration and present lower electrical resistivity. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3740–3750
Application of a PEG precipitation method for solubility screening: A tool for developing high protein concentration formulations
Authors: Li Li , Kantor Angela , Warne Nicholas
Published: June 2013

Previous publications demonstrated that the extrapolated solubility by polyethylene glycol (PEG) precipitation method (Middaugh et al., J Biol Chem 1979; 254:367–370; Juckes, Biochim Biophys Acta 1971; 229:535–546; Foster et al., Biochim Biophys Acta 1973; 317:505; Mahadevan and Hall, AIChE J 1990; 36:1517–1528; Stevenson and Hageman, Pharm Res 1995; 12:1671–1676) has a strong correlation to experimentally measured solubility of proteins. Here, we explored the utility of extrapolated solubility as a method to compare multiple protein drug candidates when nonideality of a highly soluble protein prohibits accurate quantitative solubility prediction. To achieve high efficiency and reduce the amount of protein required, the method is miniaturized to microwell plate format for high‐throughput screening application. In this simplified version of the method, comparative solubility of proteins can be obtained without the need of concentration measurement of the supernatant following the precipitation step in the conventional method. The monoclonal antibodies with the lowest apparent solubilities determined by this method are the most difficult to be concentrated, indicating a good correlation between the prediction and empirical observations. This study also shows that the PEG precipitation method gives results for opalescence prediction that favorably compares to experimentally determined opalescence levels at high concentration. This approach may be useful in detecting proteins with potential solubility and opalescence problems prior to the time‐consuming and expensive development process of high concentration formulation.
Dissipation of soil fumigants from soil following repeated applications
Authors: Triky‐Dotan Shachaf , Ajwa Husein A
Published: June 2013

BACKGROUND

The dissipation of pesticides in soil and the occurrence of accelerated degradation following repeated applications are well‐known phenomena with many pesticides, but much less so with soil fumigants. The fate of various soil fumigants was studied in different agricultural soils following repeated applications of chloropicrin.

RESULTS

Fumigant dissipation reflected by Σconcentration × time (ΣC × T) and half‐life values varied widely among the tested soils. Methyl iodide (MI) had the slowest dissipation rate compared with other fumigants in all tested soils. Elimination of biotic agents by soil sterilization prior to MI application did not affect MI concentration in Oxnard soil. Clay content and fumigant dose (ΣC × T values) of chloropicrin, 1,3‐dichloropropene and MI were significantly correlated. No significant correlations were found between soil properties and ΣC × T values following metam sodium and methyl bromide (MBr) application.

CONCLUSION

The fate of the tested soil fumigants is highly dependent on and specific to the fumigant, previous fumigant application and soil type. This study suggests that biotic factors are more essential in the dissipation of metam sodium and MBr than abiotic factors. By contrast, MI dissipation from the tested soils is affected more by abiotic factors than by biotic activities. © 2013 Society of Chemical Industry.
Mechanical stress effect on the crystallization behavior of Ge2Sb2Te5 films studied by electrical resistance measurement
Authors: Du Yingchao , Kan Yi , Lu Xiaomei , Liu Yunfei , Bo Huifeng , Cai Wei , Hu Dazhi , Huang Fengzhen , Zhu Jinsong
Published: June 2013

The mechanical stress effect on the crystallization behaviour of Ge2Sb2Te5(GST) thin films is carefully investigated by electrical resistance measurements. It is found that the crystallization temperature of GST films increases as external compressive stress is applied, while the crystallization temperature decreases under tensile stress. We also find that the uneven distribution of extrinsic stress can widen the span of transition temperature. These results clearly demonstrate that mechanical stress plays an important role during the crystallization process of GST films and may further influence the reliability and storage speed of relevant devices. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A general framework for robust and efficient association analysis in family‐based designs: quantitative and dichotomous phenotypes
Authors: Won Sungho , Lange Christoph
Published: June 2013

Although transmission disequilibrium tests (TDT) and the FBAT statistic are robust against population substructure, they have reduced statistical power, as compared with fully efficient tests that are not guarded against confounding because of population substructure. This has often limited the application of transmission disequilibrium tests/FBATs to candidate gene analysis, because, in a genome‐wide association study, population substructure can be adjusted by approaches such as genomic control and EIGENSTRAT. Here, we provide new statistical methods for the analysis of quantitative and dichotomous phenotypes in extended families. Although the approach utilizes the polygenic model to maximize the efficiency, it still preserves the robustness to non‐normality and misspecified covariance structures. In addition, the proposed method performs better than the existing methods for dichotomous phenotype, and the new transmission disequilibrium test for candidate gene analysis is more efficient than FBAT statistics. Copyright © 2013 John Wiley & Sons, Ltd.
Optimal combination of number of participants and number of repeated measurements in longitudinal studies with time‐varying exposure
Authors: Barrera‐Gómez Jose , Spiegelman Donna , Basagaña Xavier
Published: June 2013

In the context of observational longitudinal studies, we explored the values of the number of participants and the number of repeated measurements that maximize the power to detect the hypothesized effect, given the total cost of the study. We considered two different models, one that assumes a transient effect of exposure and one that assumes a cumulative effect. Results were derived for a continuous response variable, whose covariance structure was assumed to be damped exponential, and a binary time‐varying exposure. Under certain assumptions, we derived simple formulas for the approximate solution to the problem in the particular case in which the response covariance structure is assumed to be compound symmetry. Results showed the importance of the exposure intraclass correlation in determining the optimal combination of the number of participants and the number of repeated measurements, and therefore the optimized power. Thus, incorrectly assuming a time‐invariant exposure leads to inefficient designs. We also analyzed the sensitivity of results to dropout, mis‐specification of the response correlation structure, allowing a time‐varying exposure prevalence and potential confounding impact. We illustrated some of these results in a real study. In addition, we provide software to perform all the calculations required to explore the combination of the number of participants and the number of repeated measurements. Copyright © 2013 John Wiley & Sons, Ltd.
Springback Theory of Plane Bending and the Progress of Study on Its Engineering Application
Authors: Zhao Jun , Zhai Ruixue , Ma Rui , Zhan Peipei , Song Xiaokang
Published: June 2013

With the rapid development of science and technology as well as increasingly fierce competition in product manufacturing, the accurate prediction, and precise control of bending springback have been the key issue to solve. Springback is the most common metal forming phenomenon. In the past few decades, a lot of research work was concentrated in the plane pure bending of straight beam. This paper made the plane curved beam with any cross‐section as studying object, carried out a systematic theoretical study based on the unloading law of classical elastic–plastic theory and the characteristic of strain superposition. The theoretical derivation was built on basic assumptions which are widely applicable. The plane bending geometric constraint equation and the springback equation were established. The springback theory of plane bending was built. The springback theory was used to these techniques as expanding roundness setting, compression roundness setting, over‐bending roundness setting, large pipe straightening, and profile stretch‐bending. The analytic results and the results obtained by computer numerical simulations and physical experiments agreed well. The theory not only further enriches the content of the classical theory of elastic–plastic bending, but also provides a theoretical basis and technical support for the springback prediction in engineering problems.
Effect of Mo Concentration on Dynamic Recrystallization Behavior of Low Carbon Microalloyed Steels
Authors: Schambron Thomas , Chen Liang , Gooch Taliah , Dehghan‐Manshadi Ali , Pereloma Elena V.
Published: June 2013

Using a Gleeble 3500 thermo‐mechanical simulator, the dynamic recrystallization (DRX) behavior and mechanical properties of four low C, Nb−Ti‐containing micro‐alloyed steels with a Mo content ranging from 0 to 0.27 wt% were investigated. The effects of Mo content, deformation temperature and strain rate on the DRX parameters were quantified. The flow curves showed the typical signs of DRX over a wide range of deformation conditions. However, at higher strain rates (5 s−1) and/or lower deformation temperatures (below 1000°C), dynamic recovery was observed. It was shown that Mo has an effect on retarding DRX in micro‐alloyed steels, most likely due to the solute drag.