bluuebunny/crossref_metadata_2025 huggingface dataset:
Hetero‐Bambusurils
Authors: Reany Ofer , Mohite Amar , Keinan Ehud
Published: February 2018

Synthetic anion carriers are essential for studying natural ion transporters and channels and for useful applications, such as treatment of channelopathies, supramolecular architecture, anion sensing and catalysis. Driven by the hypothesis that replacement of oxygen atoms in bambusurils (BUs) by other heteroatoms could significantly modify their anion binding properties, we calculated their molecular electrostatic potential and found a general trend of anion‐affinity: S>O>NH. We confirmed these predictions experimentally by synthesizing semithio‐ and semiaza‐BUs and studying their binding and transport properties. Although all analogs are excellent anion binders, only semithio‐bambus[6]uril is an effective transmembrane transporter capable of polarizing lipid membranes through selective anion uniport. Semiaza‐BUs exhibit simultaneous accommodation of three anions, linearly positioned along the main symmetry axis, which is reminiscent of natural chloride channels in E. coli.
POSTPARTUM BONDING DIFFICULTIES AND ADULT ATTACHMENT STYLES: THE MEDIATING ROLE OF POSTPARTUM DEPRESSION AND CHILDBIRTH‐RELATED PTSD
Authors: S. Hairston Ilana , E. Handelzalts Jonathan , Assis Chen , Kovo Michal
Published: February 2018

Despite decades of research demonstrating the role of adult attachment styles and early mother–infant bonding in parenting behaviors and maternal mental health, these constructs have seldom been studied together. The present study aimed to investigate the relationship between attachment styles and specific bonding difficulties of mothers. In addition, as postpartum depression and childbirth‐related posttraumatic stress symptoms have been associated with both constructs, we explored their possible mediation effect. One hundred fourteen mothers, 4 to 12 weeks’ postpartum, completed a demographic questionnaire, the Adult Attachment Style Questionnaire (M. Mikulincer, V. Florian, & A. Tolmacz, 1990), the Postpartum Bonding Questionnaire (L.F. Brockington, C. Fraser, & D. Wilson, 2006), the Modified Perinatal Posttraumatic Stress Disorder Questionnaire (J.L. Callahan, S.E. Borja, & M.T. Hynan, 2006), and the Edinburgh Postnatal Depression Scale (J.L. Cox, G. Chapman, D. Murray, & P. Jones, 1996), using an online survey system. As predicted, insecure attachment styles were associated with bonding difficulties wherein anxious/ambivalent attachment was associated with greater infant‐focused anxiety, mediated by postpartum depression but not childbirth‐related PTSD symptoms. In contrast, greater avoidant attachment style was associated with greater rejection and anger, mediated by childbirth‐related posttraumatic stress disorder (PTSD), but not depression symptoms. The current study confirmed the association of different attachment styles with bonding as well as the mediating roles of childbirth‐related PTSD and postpartum depression symptoms. Future psychological interventions may utilize such evidence to target interventions for bonding disorders in accordance with individual differences.
Parametric models to compute tryptophan fluorescence wavelengths from classical protein simulations
Authors: Lopez Alvaro J. , Martínez Leandro
Published: February 2018

Fluorescence spectroscopy is an important method to study protein conformational dynamics and solvation structures. Tryptophan (Trp) residues are the most important and practical intrinsic probes for protein fluorescence due to the variability of their fluorescence wavelengths: Trp residues emit in wavelengths ranging from 308 to 360 nm depending on the local molecular environment. Fluorescence involves electronic transitions, thus its computational modeling is a challenging task. We show that it is possible to predict the wavelength of emission of a Trp residue from classical molecular dynamics simulations by computing the solvent‐accessible surface area or the electrostatic interaction between the indole group and the rest of the system. Linear parametric models are obtained to predict the maximum emission wavelengths with standard errors of the order 5 nm. In a set of 19 proteins with emission wavelengths ranging from 308 to 352 nm, the best model predicts the maximum wavelength of emission with a standard error of 4.89 nm and a quadratic Pearson correlation coefficient of 0.81. These models can be used for the interpretation of fluorescence spectra of proteins with multiple Trp residues, or for which local Trp environmental variability exists and can be probed by classical molecular dynamics simulations. © 2018 Wiley Periodicals, Inc.
What should be the laboratory approach against isolated prolongation of a activated partial thromboplastin time?
Authors: Falay Mesude , Senes Mehmet , Yücel Dogan , Turhan Turan , Dagdaş Simten , Pekin Melike , Nazaroglu Namik K. , Özet Gülsüm
Published: February 2018

Background

This study is a retrospective evaluation of patients who were subject to mixing study in our laboratory due to prolonged APTT. The preliminary diagnoses, clinical manifestations, and results of additional ordered tests were reviewed. The study aims to investigate whether repeating APTT test with a different assay prior to performing mixed study in patients with prolonged APTT would be a better alternative algorithmic approach in order to save both time and costs.

Methods

We retrospectively evaluated 166 patients (65 females and 101 males) who were subject to mixing study due to isolated prolonged APTT. Additional ordered tests to identify the etiology and clinical findings were reviewed. All patients who had prolonged APTT as a result of testing with Hemosil Synthasil APTT reagent in ACL TOP analyzer were repeated with Stago Cephascreen APTT reagent in STA‐R coagulation analyzer.

Results

APTT test was requested preoperatively in 72.2% of cases. Only 6.6% of the cases had history of bleeding. Correction with mixing study was achieved in 122 (73.5%) cases, among which 75 (45%) cases were found to have APTT test results within reference range when tested with Cephascreen reagent. In 44 (26.5%) cases, mixing study did not result in correction. Only 4 cases were confirmed to have lupus anticoagulants (LA), while 4 cases were diagnosed with hemophilia with inhibitors.

Conclusion

Prolonged APTT results should always be retested using a different assay prior to mixing study. The clinician and the laboratory specialist should collaborate at the postanalytical phase.
Identification of a novel truncating mutation in PALB2 gene by a multigene sequencing panel for mutational screening of breast cancer risk‐associated and related genes
Authors: Guacci Anna , Cordella Angela , Rocco Teresa , Giurato Giorgio , Nassa Giovanni , Rizzo Francesca , Carlomagno Chiara , Pepe Stefano , Tarallo Roberta , Weisz Alessandro
Published: February 2018

Background

Breast cancer (BC) is the most common neoplasm in women, with 5%‐10% patients showing a familial predisposition, where germline mutations in BRCA1/BRCA2 genes are found in –20% of cases. Next‐generation sequencing (NGS) is among the best available options for genetic screening, providing several benefits that include enhanced sensitivity and unbiased mutation detection. PALB2 (partner and localizer of BRCA2) is a cancer predisposing gene recently described that encodes a protein partner of BRCA2 involved in DNA double‐strand break repair and cell cycle control. The DNA damage response represents a key cellular event, targeted by innovative anticancer therapies, including those based on poly (ADP‐ribose) polymerase (PARP) inhibitors targeting PARP1 and PARP2 enzymes, activated by DNA damage and involved in single‐strand break and base excision repair.

Methods

Genomic DNA was isolated from 34 patient samples and four BC cell lines, as controls, and 27 breast cancer predisposing genes belonging to the BRCA1/BRCA2 and PARP pathways were sequenced by NGS.

Results

The panel described here allowed identification of several sequence variations in most investigated genes, among which we found a novel truncating mutation in PALB2.

Conclusions

The NGS‐based strategy designed here for molecular analysis of a customized panel of BC predisposing and related genes was found to perform effectively, providing a comprehensive exploration of all genomic sequences of the investigated genes. It is thus useful for BC molecular diagnosis, in particular for familiar cases where alterations in routinely investigated genes, such as BRCAs, result to be absent.
Regulatory Perspectives in Pharmacometric Models of Osteoporosis
Authors: Madrasi Kumpal , Li Fang , Kim Myong‐Jin , Samant Snehal , Voss Stephen , Kehoe Theresa , Bashaw E. Dennis , Ahn Hae Young , Wang Yaning , Florian Jeffy , Schmidt Stephan , Lesko Lawrence J. , Li Li
Published: February 2018

Osteoporosis is a disorder of the bones in which they are weakened to the extent that they become more prone to fracture. There are various forms of osteoporosis: some of them are induced by drugs, and others occur as a chronic progressive disorder as an individual gets older. As the median age of the population rises across the world, the chronic form of the bone disease is drawing attention as an important worldwide health issue. Developing new treatments for osteoporosis and comparing them with existing treatments are complicated processes due to current acceptance by regulatory authorities of bone mineral density (BMD) and fracture risk as clinical end points, which require clinical trials to be large, prolonged, and expensive to determine clinically significant impacts in BMD and fracture risk. Moreover, changes in BMD and fracture risk are not always correlated, with some clinical trials showing BMD improvement without a reduction in fractures. More recently, bone turnover markers specific to bone formation and resorption have been recognized that reflect bone physiology at a cellular level. These bone turnover markers change faster than BMD and fracture risk, and mathematically linking the biomarkers via a computational model to BMD and/or fracture risk may help in predicting BMD and fracture risk changes over time during the progression of a disease or when under treatment. Here, we discuss important concepts of bone physiology, osteoporosis, treatment options, mathematical modeling of osteoporosis, and the use of these models by the pharmaceutical industry and the Food and Drug Administration.
Comparative SEM and LM foliar epidermal and palyno‐morphological studies of Amaranthaceae and its taxonomic implications
Authors: Hussain Amara Noor , Zafar Muhammad , Ahmad Mushtaq , Khan Raees , Yaseen Ghulam , Khan Muhammad Saleem , Nazir Abdul , Khan Amir Muhammad , Shaheen Shabnum
Published: February 2018

Palynological features as well as comparative foliar epidermal using light and scanning electron microscope (SEM) of 17 species (10genera) of Amaranthaceae have been studied for its taxonomic significance. Different foliar and palynological micro‐morphological characters were examined to explain their value in resolving the difficulty in identification. All species were amphistomatic but stomata on abaxial surface were more abundant. Taxonomically significant epidermal character including stomata type, trichomes (unicellular, multicellular, and capitate) and epidermal cells shapes (polygonal and irregular) were also observed. Pollens of this family are Polypantoporate, pores large, spheroidal, mesoporous region is sparsely to scabrate, densely psilate, and spinulose. All these characters can be active at species level for identification purpose. This study indicates that at different taxonomic levels, LM and SEM pollen and epidermal morphology is explanatory and significant to identify species and genera.
Conditional cash transfers and the reduction in partner violence for young women: an investigation of causal pathways using evidence from a randomized experiment in South Africa (HPTN 068)
Authors: Kilburn Kelly N , Pettifor Audrey , Edwards Jessie K , Selin Amanda , Twine Rhian , MacPhail Catherine , Wagner Ryan , Hughes James P , Wang Jing , Kahn Kathleen
Published: February 2018

Introduction

Evidence has shown that the experience of violence by a partner has important influences on women's risk of HIV acquisition. Using a randomized experiment in northeast South Africa, we found that a conditional cash transfer (CCT) targeted to poor girls in high school reduced the risk of physical intimate partner violence (IPV) in the past 12 months by 34%. The purpose of this analysis is to understand the pathways through which the CCT affects IPV.

Methods

HPTN 068 was a phase 3, randomized controlled trial in rural Mpumalanga province, South Africa. Eligible young women (aged 13–20) and their parents or guardians were randomly assigned (1:1) to either receive a monthly cash transfer conditional on monthly high school attendance or no cash transfer. Between 2011 and 2015, participants (N = 2,448) were interviewed at baseline, then at annual follow‐up visits at 12, 24 and 36 months. The total effect of the CCT on IPV was estimated using a GEE log‐binomial regression model. We then estimated controlled direct effects to examine mediation of direct effects through intermediate pathways. Mediators include sexual partnership measures, the sexual relationship power scale, and household consumption measures.

Results

We found evidence that the CCT works in part through delaying sexual debut or reducing the number of sexual partners. The intervention interacts with these mediators leading to larger reductions in IPV risk compared to the total effect of the CCT on any physical IPV [RR 0.66, CI(95%):0.59–0.74]. The largest reductions are seen when we estimate the controlled direct effect under no sexual debut [RR 0.57, CI(95%):0.48–0.65] or under no sexual partner in the last 12 months [RR 0.53, CI(95%):0.46–0.60].

Conclusions

Results indicate that a CCT for high school girls has protective effects on their experience of IPV and that the effect is due in part to girls choosing not to engage in sexual partnerships, thereby reducing the opportunity for IPV. As a lower exposure to IPV and safer sexual behaviours also protect against HIV acquisition, this study adds to the growing body of evidence on how cash transfers may reduce young women's HIV risk.
Ending AIDS by 2030: the importance of an interlinked approach and meaningful youth leadership
Authors: Gleeson Hayley S , Oliveras Rodriguez Carlo André , Hatane Luann , Hart Doortje‘t
Published: February 2018

Introduction

This commentary by authors from the Adolescent HIV Treatment Coalition calls for action to improve advocacy and service delivery for young people by leveraging the interlinkages between HIV and the broader development agenda. The 2030 Agenda for Sustainable Development includes target 3.3 on ending the AIDS epidemic by 2030, and along with the 2016 Political Declaration on HIV and AIDS, this has led to a global renewal of political commitment to the HIV response. However, young people are still being left behind, and to provide an equitable and sustainable response to HIV we must ensure that we are meeting the needs of the 3.9 million young people living with HIV, and the millions more at risk.

Discussion

While HIV has its own target within the 2030 Agenda, efforts to end AIDS are inextricable from other goals and targets, such as on poverty eradication, education, gender equality and peace. To tackle HIV we must work beyond target 3.3 and provide a comprehensive response that addresses the underlying structural inequalities that impact adolescents and young people, ensuring that we enable the meaningful engagement of youth and adolescents as partners and leaders of sustainable development and the HIV response. Finally, it is necessary to collect better disaggregated data and evidence on the HIV epidemic among adolescents, as well as on best practices for supporting them.

Conclusions

Ending the AIDS epidemic among adolescents and young people (aged 10 to 24) by 2030 is possible. However, it requires an integrated, multi‐sectoral response to HIV which pays attention to the social determinants that put adolescents at risk and fuel the epidemic. Positioning efforts to end AIDS among young people within the broader 2030 Agenda and building youth leadership will contribute to building a more healthy, equitable and sustainable society for all.
Interpretation of results from the competitive Biacore procedure for characterizing immunochemical interactions in solution
Authors: Winzor Donald J.
Published: February 2018

Rigorous consideration of the consequences of antibody bivalence in the published competitive kinetic procedure for quantifying the solution characteristics of an antigen‐antibody interaction in solution has rendered redundant the practice of substituting the Fab fragment for the antibody to ensure validity of the analysis of results in terms of theory developed for a univalent analyte. Although the quantitative expressions differ for univalent and bivalent analytes, the additional contribution arising from bivalence is likely to be well within the limits of experimental uncertainty in the measured binding constant.
Raman spectroscopy coupled to chemometrics to discriminate provenance and geological age of amber
Authors: Peris‐Díaz Manuel David , Łydżba‐Kopczyńska Barbara , Sentandreu Enrique
Published: February 2018

Raman spectroscopy coupled to partial least squares (PLS) was used for the classification of amber samples according to their provenance and geological age. Spectral data were from samples from Czech Republic, Baltic region, and objects dated back from Upper Cretaceous and Cenozoic ages. Intensity ratio of two wavenumbers has been used as indicator of both geological age and provenance amber so far.

In this work, an alternative chemometric approach was proposed to select additional intervals of the spectra where discrimination relies. Several metrics (number of misclassifications and permutation test) evaluated the capability of the alternative PLS models to predict future measurements.

Results achieved indicated the possibility to assess the geological age and provenance of amber considering an interval of wavenumbers instead of single wavenumbers that could be disturbed by physical effects. Furthermore, differences in the Raman spectra were highlighted by using Variable Importance Projection methodology over PLS model. The proposed methodology clearly distinguished Baltic from Czech Republic amber and resins from Cenozoic period and Upper Cretaceous. This research could represent a breakthrough for amber cultural heritage studies.
Chlortetracycline and related tetracyclines: detection in wheat and rye grain
Authors: Schwake‐Anduschus Christine , Langenkämper Georg
Published: February 2018

BACKGROUND

Antibiotic drugs are excreted to a large proportion by livestock. Thus, antibiotics are distributed on fields with slurry and can be taken up by plants. In the present study, hydroponic experiments were performed to reveal whether the widely administered chlortetracycline is taken up into wheat grain in a concentration‐dependent manner. A further goal was to determine (chlor)tetracyclines in wheat and rye grain from agricultural practice.

RESULTS

Increasing chlortetracycline deposition in wheat grain was observed with a rising chlortetracycline spiking level in the hydroponic solution. In 371 selected wheat and rye samples from three growing years of agricultural practice, the overall detection frequency was 21% for tetracyclines. In the most highly contaminated sample, tetracyclines occurred at 18.2 μg kg–1. Tetracycline residues were also found in rye grain. Conversion and degradation products of (chlor)tetracycline such as tetracycline, doxycycline and demeclocycline were detected in grains from hydroponic experiments and from agricultural practice.

CONCLUSION

Concentrations of tetracyclines found in wheat and rye grains were of no concern with respect to toxicity regarding human consumption. However, antibiotic concentrations below the minimum inhibitory concentration can select for antibiotic resistance in bacteria. Thus, low levels of different tetracycline residues contained in food should be taken into account regarding risk assessment. © 2018 Society of Chemical Industry
Development and prospective validation of a model estimating risk of readmission in cancer patients
Authors: Schmidt Carl R. , Hefner Jennifer , McAlearney Ann S. , Graham Lisa , Johnson Kristen , Moffatt‐Bruce Susan , Huerta Timothy , Pawlik Timothy M. , White Susan
Published: February 2018

Introduction

Hospital readmissions among cancer patients are common. While several models estimating readmission risk exist, models specific for cancer patients are lacking.

Methods

A logistic regression model estimating risk of unplanned 30‐day readmission was developed using inpatient admission data from a 2‐year period (n = 18 782) at a tertiary cancer hospital. Readmission risk estimates derived from the model were then calculated prospectively over a 10‐month period (n = 8616 admissions) and compared with actual incidence of readmission.

Results

There were 2478 (13.2%) unplanned readmissions. Model factors associated with readmission included: emergency department visit within 30 days, >1 admission within 60 days, non‐surgical admission, solid malignancy, gastrointestinal cancer, emergency admission, length of stay >5 days, abnormal sodium, hemoglobin, or white blood cell count. The c‐statistic for the model was 0.70. During the 10‐month prospective evaluation, estimates of readmission from the model were associated with higher actual readmission incidence from 20.7% for the highest risk category to 9.6% for the lowest.

Conclusions

An unplanned readmission risk model developed specifically for cancer patients performs well when validated prospectively. The specificity of the model for cancer patients, EMR incorporation, and prospective validation justify use of the model in future studies designed to reduce and prevent readmissions.
Hyperthermic isolated limb perfusion, preoperative radiotherapy, and surgery (PRS) a new limb saving treatment strategy for locally advanced sarcomas
Authors: Stevenson Marc G. , Seinen Jojanneke M. , Pras Elisabeth , Brouwers Adrienne H. , van Ginkel Robbert J. , van Leeuwen Barbara L. , Suurmeijer Albert J. H. , Been Lukas B. , Hoekstra Harald J.
Published: February 2018

Background

This feasibility study presents the results of a new intensive treatment regimen for locally advanced extremity soft tissue sarcomas (ESTS), consisting of hyperthermic isolated limb perfusion (HILP), preoperative external beam radiotherapy (EBRT), and surgical resection.

Methods

From 2011 to 2016, 11 high grade locally advanced ESTS patients underwent this treatment regimen. Preoperative EBRT (12 × 3 Gy) started <4 weeks following the HILP (TNF‐α and melphalan) and the surgical resection was planned to take place <2 weeks following the end of the EBRT.

Results

All patients completed the treatment. After a median follow‐up of 32 (23‐50) months, the limb was saved in 10 patients (91%), 1 patient (9%) developed a local recurrence, 5 patients (45%) developed distant metastases, and 3 patients (27%) died of their disease. During follow‐up two patients (18%) developed a pathologic fracture of the treated limb and three patients (27%) developed a major wound complication requiring surgical intervention. The median overall treatment time (OTT) was 56 (49‐69) days.

Conclusions

This intensive treatment regimen is feasible and safe in locally advanced ESTS, and it achieves oncological results that are comparable with conventional HILP treatment. In addition, the major wound complication risk is comparable and the OTT is reduced.
Nasolabial propeller perforator flap: Anatomical study and case series
Authors: Posso Carolina , Delgado Anaya David , Aguilar Henao Jeison , Velasquez Gaviria Juan M.
Published: February 2018

Purpose

The previous cadaveric studies of facial artery perforators have frequently reported high variability, and those results remain to be validated in the Colombian population. Thus, we aimed to describe the vascular anatomy of the lateral nasal artery cutaneous branches and their clinical applications using Colombian cadavers.

Materials and Methods

Nine hemifaces from six fresh cadavers were included in the study. Terminal branches of the facial artery and cutaneous perforators of the lateral nasal artery were dissected. The quality, number, and distribution of the perforators were assessed. In addition, we present results of seven clinical cases for nasal alar reconstruction.

Results

Cutaneous perforators were found in all hemifaces, and zone 2 was the most common location. In our clinical case series, all flaps used to reconstruct the nasal alar defects survived. There were two cases of venous congestion but no additional procedures were needed.

Conclusions

Although nasal alar reconstruction continues to be a challenging plastic surgery procedure, the nasolabial propeller perforator flap is an excellent choice for such because it allows a precise skin island design, is less bulky, has a wide arc of rotation, and facilitates one‐staged reconstruction without increasing the rate of complications.
Considering the cost of a simultaneous versus staged approach to resection of colorectal cancer with synchronous liver metastases in a publicly funded healthcare model
Authors: Le Souder Emily B. , Azin Arash , Hirpara Dhruvin H. , Walker Richard , Cleary Sean , Quereshy Fayez
Published: February 2018

Background

Simultaneous resection for colorectal cancer with synchronous liver metastases is an established alternative to a staged approach. This study aimed to compare these approaches with regards to economic parameters and short‐term outcomes.

Methods

A retrospective cohort analysis was conducted between 2005 and 2016. The primary outcome was cost per episode of care. Secondary measures included 30‐day clinical outcomes. A multivariate analysis was performed to determine the adjusted effect of a simultaneous surgical approach on total cost of care.

Results

Fifty‐three cases were identified; 27 in the staged approach, and 26 in the simultaneous group. Age (P = 0.49), sex (P = 0.20), BMI (P = 0.74), and ASA class (P = 0.44) were comparable between groups. Total cost ($20297 vs $27522), OR ($6830 vs $10376), PACU ($675 vs $1182), ward ($7586 vs $11603) and pharmacy costs ($728 vs $1075) were significantly less for the simultaneous group (P < 0.05). The adjusted rate ratio for total cost of care in the staged group compared to simultaneous group was 1.51 (95%CI: 1.16‐1.97, P < 0.05). The groups had comparable Clavien‐Dindo scores (P = 0.89), 30‐day readmissions (P = 0.44), morbidity (P = 0.50) and mortality (P = 1.00).

Conclusions

Our study demonstrates that a simultaneous approach is associated with a significantly lower total cost while maintaining comparable short‐term outcomes.
Application of response surface methodology to vortex‐assisted dispersive liquid–liquid extraction for the determination of nicotine and cotinine in urine by gas chromatography–tandem mass spectrometry
Authors: Yuan Yue , Wang Yan , Yang Mingqi , Xu Yicong , Chen Weina , Zou Xiaoli , Zheng Bo
Published: February 2018

A method of vortex‐assisted dispersive liquid–liquid extraction coupled with gas chromatography and tandem mass spectrometry for the determination of nicotine and cotinine in urine was developed. Response surface methodology was applied to obtain the optimum extraction conditions. In this method, Plackett–Burman design was utilized to evaluate the impact of five selected factors on pretreatment procedure. Then, three main factors were optimized using a Box–Behnken design. The optimized method showed good linearities at 1–2000 μg/L with correlation coefficients of 0.9998 for nicotine and 0.9986 for cotinine. Recovery was 91.4–106 and 91.7–108% for nicotine and cotinine, respectively. The intraday relative standard derivations of determination were 1.47–4.06% for nicotine and 0.41–3.16% for cotinine, and interday relative standard derivations were 3.03–6.70% for nicotine and 1.64–6.38% for cotinine. The method detection limits for nicotine and cotinine were 0.33 and 0.34 μg/L, respectively. A total of 87 urine samples from smokers and nonsmokers were tested with the proposed method. Urinary nicotine and cotinine were 23.0–6.67 × 103 and 18.4–4.17 × 103 μg/(g·cr) for smokers and 1.31–286 and 1.39–131 μg/(g·cr) for nonsmokers, respectively. The method is sensitive, suitable and reliable for the determination of nicotine and cotinine in urine and meets the requirements for evaluating short‐term tobacco exposure.
Development of a liquid chromatography–tandem mass spectrometry method for simultaneous determination of five isoflavonoids and seven neurochemicals in rat brain dialysate and its application to a pharmacological study
Authors: Xiao Bingxin , Dong Jie , Yan Mingzhu , Liu Yun , Li Yanli , Yang Guangsheng , Sun Zengxian
Published: February 2018

Pueraria lobata is a medicinal plant widely used in traditional Chinese medicine. The total pueraria isoflavones have demonstrated positive effect against neurological disorders. In the present study, we first develop an ultra high performance liquid chromatography and tandem mass spectrometry method to quantify the multiple active pueraria isoflavonoids and neurochemical markers in brain dialysate to provide tools for further exploring the functional mechanism of pueraria isoflavones for neuroactivities. A phenomenex Luna C18 column (50 × 2.0 mm, 5 μm) was employed with acetonitrile/0.05% formic acid in water as the mobile phase for the separation of analytes. A mass spectrometer with electrospray ionization source in positive/negative ion switching mode was used for multiple reaction monitoring of the detected compounds. The method was validated and proved acceptable. The intra‐ and interday precision across quality control levels was within 13.87 for all analytes, whereas the deviation of assay accuracies ranged between 0.03 and 11.53%. The method was successfully applied to a pharmacological study of pueraria isoflavones in rat brain.
Effect of HAP decomposition on the corrosion behavior of Ti–HAP biocomposites
Authors: Toptan Fatih , Alves Alexandra C. , Ferreira Margarida A. , da Silva Oliveira Catarina I. , Pinto Ana M.P.
Published: February 2018

Ti–HAP biocomposites are gained attention for combining the attractive properties of Ti and hydroxyapatite (HAP). However, the decomposition of HAP at elevated processing temperatures is a major concern since it can lead to structural flaws and may deteriorate the corrosion resistance of Ti. The present study aims to investigate the corrosion behavior of Ti–HAP composite processed by powder metallurgy by performing potentiodynamic polarization and electrochemical impedance spectroscopy in 0.9 wt% NaCl solution at body temperature. Results show that the presence of Ti lowers the HAP decomposition temperatures resulting in the formation of HAP‐depleted zones acting as electrochemically active sites, decreasing the corrosion resistance.
Korovkin‐type results for multivariate functions which are periodic with respect to one variable
Authors: Popa Dumitru
Published: February 2018

Let K be a compact metric space and let denote the real Banach space of all continuous functions which are 2π‐periodic with respect to the second variable. We prove the following Korovkin‐type result: Let be a continuous algebraic separating function such that for all , and let be a sequence of positive linear operators. If uniformly with respect to and uniformly on for all , then uniformly on for every .
As a corollary we deduce: If , then uniformly on for every if and only if uniformly on for every , where and .
Microbial dynamics during harmful dinoflagellate Ostreopsis cf. ovata growth: Bacterial succession and viral abundance pattern
Authors: Guidi Flavio , Pezzolesi Laura , Vanucci Silvana
Published: February 2018

Algal–bacterial interactions play a major role in shaping diversity of algal associated bacterial communities. Temporal variation in bacterial phylogenetic composition reflects changes of these complex interactions which occur during the algal growth cycle as well as throughout the lifetime of algal blooms. Viruses are also known to cause shifts in bacterial community diversity which could affect algal bloom phases. This study investigated on changes of bacterial and viral abundances, bacterial physiological status, and on bacterial successional pattern associated with the harmful benthic dinoflagellate Ostreopsis cf. ovata in batch cultures over the algal growth cycle. Bacterial community phylogenetic structure was assessed by 16S rRNA gene ION torrent sequencing. A comparison between bacterial community retrieved in cultures and that one co‐occurring in situ during the development of the O. cf. ovata bloom from where the algal strain was isolated was also reported. Bacterial community growth was characterized by a biphasic pattern with the highest contributions (~60%) of highly active bacteria found at the two bacterial exponential growth steps. An alphaproteobacterial consortium composed by the Rhodobacteraceae Dinoroseobacter (22.2%–35.4%) and Roseovarius (5.7%–18.3%), together with Oceanicaulis (14.2‐40.3%), was strongly associated with O. cf. ovata over the algal growth. The Rhodobacteraceae members encompassed phylotypes with an assessed mutualistic‐pathogenic bimodal behavior. Fabibacter (0.7%–25.2%), Labrenzia (5.6%–24.3%), and Dietzia (0.04%–1.7%) were relevant at the stationary phase. Overall, the successional pattern and the metabolic and functional traits of the bacterial community retrieved in culture mirror those ones underpinning O. cf. ovata bloom dynamics in field. Viral abundances increased synoptically with bacterial abundances during the first bacterial exponential growth step while being stationary during the second step. Microbial trends also suggest that viruses induced some shifts in bacterial community composition.
Interspecific Interactions May Influence Reef Fish Management Strategies in the Gulf of Mexico
Authors: Masi M. D. , Ainsworth C. H. , Kaplan I. C. , Schirripa M. J.
Published: February 2018

This study highlights the importance of interspecific interactions among marine organisms and the effect that these trophic interactions have on the development of effective, adaptive management strategies for reef fishes in the Gulf of Mexico. To represent the spatially and temporally constrained, interspecific interactions among reef fishes we employ Atlantis (a spatially explicit, biogeochemical ecosystem model) as our simulation tool. Within Atlantis, we evaluate the performance of a two-point harvest control rule (HCR) that adaptively increases fishing mortality linearly between upper and lower biomass thresholds based on the available biomass of the stocks. This example demonstrated the use of a “blanket” two-point HCR that assessed the available biomass of several reef fish species (often co-caught in fishing gear) both simultaneously and objectively. To estimate the impact of reef fish fishing on species abundance and biodiversity in the ecosystem, we examined four “low” and four “high” fishing mortality (F) scaler scenarios. All model projections are forward looking, representing a 50-year time horizon (2010 to 2060). We evaluated the performance of the two-point HCRs under the eight fishing mortality scenarios using ecosystem metrics that were previously found to robustly track changes in ecosystem function caused by fishing. We found that the lower F scenarios produced an ecologically distinct ecosystem state compared with the higher F scenarios, where relatively higher levels of fishing mortality (particularly on predators such as the deep Serranidae group) resulted in an increase in prey availability in later years of the simulation. This led to an increase in the overall productivity of the ecosystem over time and higher catch and biomass of most other reef fish groups at equilibrium (year 50). Our results suggest that a better understanding of interspecific interactions among targeted reef fishes and their prey is critical to developing ecosystem-based management strategies for the Gulf of Mexico.
Assisting Ecosystem-Based Fisheries Management Efforts Using a Comprehensive Survey Database, a Large Environmental Database, and Generalized Additive Models
Authors: Grüss Arnaud , Chagaris David D. , Babcock Elizabeth A. , Tarnecki Joseph H.
Published: February 2018

Statistical habitat models, such as generalized additive models (GAMs), are key tools for assisting ecosystem-based fisheries management (EBFM) efforts. Predictions from GAMs can be used, for example, to produce preference functions for the ecosystem-modeling platform Ecospace; preference functions permit a flexible representation of spatial distribution patterns in Ecospace by defining the preferences of marine organisms for certain environmental parameter values. Generalized additive model predictions can also be used to map species distributions for assisting marine protected area (MPA) planning. In this study, we applied a recently proposed methodology to produce preference functions for the fish and invertebrates represented in an Ecospace model of the West Florida Shelf (WFS) and to map the hotspots of juveniles and adults of three economically important species for informing future MPA planning in the WFS region. This proposed methodology consists of (1) compiling a comprehensive survey database blending all of the encounter and nonencounter data of the study ecosystem collected by the fisheries-independent and fisheries-dependent surveys that employ random sampling schemes, (2) developing a large environmental database to store all of the environmental parameters influencing the spatial distribution patterns of the marine organisms of the study ecosystem, (3) using the comprehensive survey database and the large environmental database to fit binomial GAMs that integrate the confounding effects of survey and year, and (4) making predictions with fitted GAMs to define preference functions for marine organisms and produce distribution and hotspot maps. All the GAMs we fitted were able to predict probabilities of encounter with reasonable or excellent discrimination and had a median adjusted coefficient of determination larger than the 0.1 threshold required for validation. The preference functions and hotspot maps produced using the fitted GAMs were generally in concordance with the literature. The methodology demonstrated in this study is timely, given the increasing interest in advancing EBFM worldwide.
Effect of Bait Type and Bait Size on Catch Efficiency in the European Hake Merluccius merluccius Longline Fishery
Authors: Sistiaga Manu , Herrmann Bent , Rindahl Lasse , Tatone Ivan
Published: February 2018

We investigated the effect of bait type and bait size on the catch efficiency of a demersal longline fishery targeting European Hake Merluccius merluccius in the North Sea. Automation of the labor-intensive processes onboard fishing vessels requires finding alternatives to the traditional bait used in the fishery (i.e., whole European Pilchard Sardina pilchardus). Of the six alternative baits investigated, four resulted in significant reductions in catch efficiency ranging from 32% to 90%. Only chopped Atlantic Herring Clupea harengus was a reasonable alternative bait, with an estimated non-significant loss of only 2.12% in European Hake catch efficiency. Our results demonstrated that choice of bait type and size can affect the catch efficiency of different sizes of European Hake. Thus, the choice of bait may also affect the size distribution of the catch. The latter highlights the importance of considering fish size when inferring the effect of bait choice on the catch efficiency of longline fisheries.
New polymyxin derivatives that display improved efficacy in animal infection models as compared to polymyxin B and colistin
Authors: Vaara Martti
Published: February 2018

Polymyxin B and colistin (polymyxin E) are bactericidal pentacationic lipopeptides that act specifically on Gram‐negative bacteria, first by disrupting their outermost permeability barrier, the outer membrane (OM), and then damaging the cytoplasmic membrane. The discovery of both polymyxin B and colistin was published independently by three laboratories as early as in 1947. They were subsequently used in intravenous therapy. Unfortunately, they also exhibit significant and dose‐limiting nephrotoxicity. Therefore, polymyxins were reserved as agents of last‐line defense. The emergence of extremely multiresistant strains has now forced clinicians to reinstate polymyxins in the therapy of severe infections. However, the current dosage regimens lead to insufficient drug concentrations in serum and clinicians have been advised to use larger doses, which further increases the risk of nephrotoxicity. Very recently, the interest in developing better tolerated and more effective polymyxins has grown. This review focuses on describing four development programs that have yielded novel derivatives that are more effective than the old polymyxins in animal infection models. Compounds from three programs are superior to the old polymyxins in the rodent lung infection model with Acinetobacter baumannii and/or Pseudomonas aeruginosa. One of them is also more effective than polymyxin B in A. baumannii mouse thigh infection. The fourth program includes compounds that are approximately tenfold more effective in Escherichia coli murine pyelonephritis than polymyxin B.
Optimal control and basic reproduction numbers for a compartmental spatial multipatch dengue model
Authors: Bock Wolfgang , Jayathunga Yashika
Published: February 2018

Dengue is a vector‐borne viral disease increasing dramatically over the past years due to improvement in human mobility. In this work, a multipatch model for dengue transmission dynamics is studied, and by that, the control efforts to minimize the disease spread by host and vector control are investigated. For this model, the basic reproduction number is derived, giving a choice for parameters in the endemic case. The multipatch system models the host movement within the patches, which coupled via a residence‐time budgeting matrix P. Numerical results confirm that the control mechanism embedded in incidence rates of the disease transmission effectively reduces the spread of the disease.
A series of the solutions for the Heisenberg ferromagnetic spin chain equation
Authors: Ma Yu‐Lan , Li Bang‐Qing , Fu Ying‐Ying
Published: February 2018

The Heisenberg ferromagnetic spin chain equation is investigated. By applying the improved F‐expansion method (Exp‐function method) and the Jacobi elliptic method, respectively, a series of exact solutions is constructed. The parametric conditions of the existence for the solutions are presented. These solutions comprise periodic wave solutions, doubly periodic wave solutions, and dark and bright soliton solutions, which are expressed in several different function forms, namely, Jacobi elliptic function, trigonometric function, hyperbolic function, and exponential function. The results illustrate that the Exp‐function method is a powerful symbolic algorithm to look for new solutions for the nonlinear evolution systems.
Diffusion MRI visualization
Authors: Schultz Thomas , Vilanova Anna
Published: February 2018

Modern diffusion magnetic resonance imaging (dMRI) acquires intricate volume datasets and biological meaning can only be found in the relationship between its different measurements. Suitable strategies for visualizing these complicated data have been key to interpretation by physicians and neuroscientists, for drawing conclusions on brain connectivity and for quality control. This article provides an overview of visualization solutions that have been proposed to date, ranging from basic grayscale and color encodings to glyph representations and renderings of fiber tractography. A particular focus is on ongoing and possible future developments in dMRI visualization, including comparative, uncertainty, interactive and dense visualizations.
Parallel split least‐squares mixed finite element method for parabolic problem
Authors: Zhang Jiansong , Liu Zhaohui , Yang Danping , Zhu Jiang
Published: February 2018

Based on overlapping domain decomposition, a new class of parallel split least‐squares (PSLS) mixed finite element methods is presented for solving parabolic problem. The algorithm is fully parallel. In the overlapping domains, the partition of unity is applied to distribute the corrections reasonably, which makes that the new method only needs one or two iteration steps to reach given accuracy at each time step while the classical Schwarz alternating methods need many iteration steps. The dependence of the convergence rate on the spacial mesh size, time increment, iteration times, and subdomains overlapping degree is analyzed. Some numerical results are reported to confirm the theoretical analysis.
Translational Chemistry Meets Gluten‐Related Disorders
Authors: Lammers Karen M. , Herrera Maria G. , Dodero Veronica I.
Published: February 2018

Gluten‐related disorders are a complex group of diseases that involve the activation of the immune system triggered by the ingestion of gluten. Among these, celiac disease, with a prevalence of 1 %, is the most investigated, but recently, a new pathology, named nonceliac gluten sensitivity, was reported with a general prevalence of 7 %. Finally, there other less‐prevalent gluten‐related diseases such as wheat allergy, gluten ataxia, and dermatitis herpetiformis (with an overall prevalence of less than 0.1 %). As mentioned, the common molecular trigger is gluten, a complex mixture of storage proteins present in wheat, barley, and a variety of oats that are not fully degraded by humans. The most‐studied protein related to disease is gliadin, present in wheat, which possesses in its sequence many pathological fragments. Despite a lot of effort to treat these disorders, the only effective method is a long‐life gluten‐free diet. This Review summarizes the actual knowledge of gluten‐related disorders from a translational chemistry point of view. We discuss what is currently known from the literature about the interaction of gluten with the gut and the critical host responses it evokes and, finally, connect them to our current and novel molecular understanding of the supramolecular organization of gliadin and the 33‐mer gliadin peptide fragment under physiological conditions.
The Incidental Fertility Effects of School Condom Distribution Programs
Authors: Buckles Kasey S. , Hungerman Daniel M.
Published: February 2018

While the fertility effects of improving teenagers’ access to contraception are theoretically ambiguous, most empirical work has shown that access decreases teen fertility. In this paper, we consider the fertility effects of access to condoms—a method of contraception not considered in prior work. We exploit variation across counties and across time in teenagers’ exposure to condom distribution programs in schools. We find that access to condoms in schools increases teen fertility by about 12 percent. The results suggest that the effects of condom access varied significantly across different programs; the positive fertility estimates are driven by communities where condoms are provided without mandated counseling. Programs that mandated counseling have zero or negative fertility effects, but estimates on these counties are less robust across specifications.