bluuebunny/crossref_metadata_2025 huggingface dataset:
Deprotonation, Chloride Abstraction, and Dehydrohalogenation as Synthetic Routes to Bis‐Pyrazolate Pyridyl Iron(II) Complexes
Authors: Cook Brian J. , Polezhaev Alexander V. , Chen Chun‐Hsing , Pink Maren , Caulton Kenneth G.
Published: July 2017

The process of removal of protons and chloride, dehydrohalogenation, from [(H2L)FeCl2] is investigated systematically, to understand the reactivity of the implied transient LFeII. Reaction of [(H2L)FeCl2] with 2 equiv. of LiN(SiMe3)2 yields the “‐ate” complex LiClFe2L2, as its dimer with every iron five‐coordinate in an FeN4Cl environment. To avoid Li+ cation derived from LiN(SiMe3)2, reaction of Na2L with FeCl2 gives a product from addition of water, paramagnetic Na2[NaFe(HL)(L)]2(LFeO), which reveals Na/pyrazolate Nβ interactions and a five coordinate oxo group in the OFe3Na2 core of this aggregate. Abstraction of chloride in [(H2L)FeCl2] with NaBArF4 in THF gives paramagnetic [(H2L)Fe(THF)3]2+, which fails to react with CO. Dehydrohalogenation in the presence of Ph2PC2H4PPh2, dppe, gives both [LFe(κ2‐dppe)]2(µ‐dppe)] and [LFe(κ2‐dppe)(κ1‐dppe)], diamagnetic saturated species, which can be separated by pentane extraction. Dehydrohalogenation in the presence of tBuNC gives diamagnetic [LFe(CNtBu)3]. This is selectively methylated at both pyrazolate β‐nitrogen atom to give [LMeFe(tBuNC)3]2+ which shows rich cyclic voltammetry, and which is reduced, with KC8, to diamagnetic [LMeFe(tBuNC)2]. Structure determination of some of these, together with IR data on isocyanide stretching frequencies, show L2– to be a stronger donor than LMe. First installing triflate (to avoid the more persistent chloride ligand) facilitates access to [LFe(Lewis base)3]2+ complexes, but this cation still shows relatively weak binding of CO to LFeII, which implicates weak π basicity of that d6 species. Production of paramagnetic bis‐pincer complexes [(H2L)2Fe]2+ and [(LMe)2Fe]2+ in the presence of abundant Lewis base in polar medium is demonstrated, which illustrates a pincer ligand redistribution challenge to be kept in mind when trying to maintain a 1:1 Fe:pincer ratio, for highest reactivity.
Pressure‐based alkaline lysis with immunocapture, a method for enhanced recovery in differential extraction
Authors: Martinez Vanessa , Nori Deepthi , Dimsoski Pero , McCord Bruce
Published: July 2017

A pressure‐based protocol for differential extraction has been optimized to provide a rapid and selective alternative to conventional differential extraction techniques with the advantage of an increased recovery of genomic DNA. The protocol involves treating cotton swabs containing mixtures of sperm and vaginal epithelial cells with two sets of pressure treatment using a Barocycler® NEP 2320 in alkaline conditions. This first step quantitatively and selectively removes female epithelial cells. The cotton swab is removed and further treated with alkali at 95°C for the removal of sperm cell DNA. The resultant solution provides a clean male profile at a 20:1 cell ratio. Furthermore, the inclusion of a pretreatment step involving immunomagnetic cell capture of the female cells, permits nearly complete isolation of male sperm cells at cell ratios of up to 200:1 female to male cells.
Bicistronic expression strategy for high‐level expression of recombinant proteins in Corynebacterium glutamicum
Authors: Liu Xiuxia , Zhao Zihao , Zhang Wei , Sun Yang , Yang Yankun , Bai Zhonghu
Published: July 2017

Directly using the promoter associated with 5′‐untranslated region of a high‐protein‐abundance gene from the genome may cause low expression activity of an expression system. A bicistronic expression part containing the short 5′ coding sequence of the source gene and an embedded Shine–Dalgarno sequence can cause higher expression levels of the recombinant gene in a bicistronic cassette. Here, we evaluated two methods to construct expression parts and exploited genomic sequence sources to provide specific functional sequences to complete the expression system. The architecture of the bicistronic part increased the expression levels of target genes and performed more reliably than conventional expression parts with the same promoter and 5′ untranslated region. For Corynebacterium glutamicum, the strongest bicistronic part, HP‐BEP4, was obtained from a heterologous sequence source, leading to a 2.24‐fold increase in the expression level of fluorescent protein over constitutively expressed pXMJ19 or the production of more than 100 mg/L single‐chain variable fragment (scFv). It could meet the needs of overexpressing key genes in C. glutamicum.
A study of DNA damage in buccal cells of consumers of well‐ and/or tap‐water using the comet assay: Assessment of occupational exposure to genotoxicants
Authors: Vazquez Boucard Celia , Lee‐Cruz Larisa , Mercier Laurence , Ramírez Orozco Martín , Serrano Pinto Vania , Anguiano Gerardo , Cazares Linette , Díaz Daniel
Published: July 2017

Because of concerns that natural aquifers in the region of Todos Santos (Baja California Sur, Mexico) might be contaminated by organochlorine pesticides and heavy metals, a case–control study was conducted among consumers and non‐consumers of well‐ and/or tap‐water to determine risks to human health. This study was based on a genotoxic evaluation of buccal cells using the Comet assay technique. Levels of DNA damage in the consumers group were significantly higher than those of the control group. However, occupational exposure to genotoxicants showed to be the critical factor rather than water consumption. Taking into account the professions of well‐ and/or tap‐water consumers, agricultural workers exposed directly (those who fumigated) or indirectly (those not involved in fumigating) to agrochemicals showed greater genetic damage than controls. This difference persisted even when age, and whether the person smoked or consumed alcoholic drinks were considered. These factors were not associated with the level of genetic damage observed. Chemical analyses of organochlorine pesticides and heavy metals were carried out to evaluate the water quality of wells, faucets, and surface water of canals consumed by the population and/or used for irrigation. High concentrations of α and β endosulfan were detected in water of surface canals. Although our inventory of agrochemicals employed in the region showed the use of products considered carcinogenic and/or mutagenic, they were not detected by the analytical techniques used. Heavy metals (arsenic, mercury, and lead) were detected in water of some wells used for irrigation and human consumption. Environ. Mol. Mutagen. 58:619–627, 2017. © 2017 Wiley Periodicals, Inc.
Assessing visibility and geomorphological biases in regional field surveys: The case of Roman Aesernia
Authors: Casarotto Anita , Stek Tesse D. , Pelgrom Jeremia , van Otterloo Ruud H. , Sevink Jan
Published: July 2017

Archaeological field survey data can be biased by many factors, such as ground visibility conditions (e.g. vegetation, plowing) and geomorphological processes (erosion, deposition). Both visibility and geomorphological factors need, therefore, to be assessed when patterns of settlement and location preferences are inferred from survey data. Although both factors have been taken into account in a variety of fieldwork projects and studies, their combined effects remain hard to predict. In this paper, we aim to address this issue by presenting a visualization method that helps in evaluating in combination the possible visibility and geomorphological effects in regional, site‐oriented field surveys. Capitalizing on first‐hand data on both archaeology and soil types produced by the recent Leiden University field survey project in the area of Isernia (Roman Aesernia, Central‐Southern Italy), we propose a combined application of statistical tests and geo‐pedological analysis to assess the extent and scale of the main biases possibly affecting the interpretation of the ancient settlement organization. Translating both sets of biases into GIS maps, we indicate the likelihood that negative field survey observations (absence of sites), in specific parts of the landscape, are genuine or rather distorted by biasing factors. The resulting “archaeological detectability” maps allow researchers to formally highlight critical surveyed zones where the recording of evidence is likely unreliable, and thus provide a filter through which archaeologists can calibrate their interpretations of field survey datasets.
Adaptive testing for association between two random vectors in moderate to high dimensions
Authors: Xu Zhiyuan , Xu Gongjun , Pan Wei ,   For the Alzheimer's Disease Neuroimaging Initiative
Published: July 2017

Testing for association between two random vectors is a common and important task in many fields, however, existing tests, such as Escoufier's RV test, are suitable only for low‐dimensional data, not for high‐dimensional data. In moderate to high dimensions, it is necessary to consider sparse signals, which are often expected with only a few, but not many, variables associated with each other. We generalize the RV test to moderate‐to‐high dimensions. The key idea is to data adaptively weight each variable pair based on its empirical association. As the consequence, the proposed test is adaptive, alleviating the effects of noise accumulation in high‐dimensional data, and thus maintaining the power for both dense and sparse alternative hypotheses. We show the connections between the proposed test with several existing tests, such as a generalized estimating equations‐based adaptive test, multivariate kernel machine regression (KMR), and kernel distance methods. Furthermore, we modify the proposed adaptive test so that it can be powerful for nonlinear or nonmonotonic associations. We use both real data and simulated data to demonstrate the advantages and usefulness of the proposed new test. The new test is freely available in R package aSPC on CRAN at https://cran.r-project.org/web/packages/aSPC/index.html and https://github.com/jasonzyx/aSPC.
Oscillations during observations: Dynamic oscillatory networks serving visuospatial attention
Authors: Wiesman Alex I. , Heinrichs‐Graham Elizabeth , Proskovec Amy L. , McDermott Timothy J. , Wilson Tony W.
Published: July 2017

The dynamic allocation of neural resources to discrete features within a visual scene enables us to react quickly and accurately to salient environmental circumstances. A network of bilateral cortical regions is known to subserve such visuospatial attention functions; however the oscillatory and functional connectivity dynamics of information coding within this network are not fully understood. Particularly, the coding of information within prototypical attention‐network hubs and the subsecond functional connections formed between these hubs have not been adequately characterized. Herein, we use the precise temporal resolution of magnetoencephalography (MEG) to define spectrally specific functional nodes and connections that underlie the deployment of attention in visual space. Twenty‐three healthy young adults completed a visuospatial discrimination task designed to elicit multispectral activity in visual cortex during MEG, and the resulting data were preprocessed and reconstructed in the time–frequency domain. Oscillatory responses were projected to the cortical surface using a beamformer, and time series were extracted from peak voxels to examine their temporal evolution. Dynamic functional connectivity was then computed between nodes within each frequency band of interest. We find that visual attention network nodes are defined functionally by oscillatory frequency, that the allocation of attention to the visual space dynamically modulates functional connectivity between these regions on a millisecond timescale, and that these modulations significantly correlate with performance on a spatial discrimination task. We conclude that functional hubs underlying visuospatial attention are segregated not only anatomically but also by oscillatory frequency, and importantly that these oscillatory signatures promote dynamic communication between these hubs. Hum Brain Mapp 38:5128–5140, 2017. © 2017 Wiley Periodicals, Inc.
Studying entrepreneurial occupations in the Terman women
Authors: Schmitt‐Rodermund Eva , Schröder Elke , Obschonka Martin
Published: July 2017

To achieve a better understanding of entrepreneurship development in women, longitudinal data on 672 individuals collected from 1922 to 1959 were analysed in a secondary investigation of the Terman Longitudinal Study. Women's reports on their occupations during 10 different years were assigned to one of two categories: work for pay (0/1), and work allowing for self‐employment (0/1) in the respective year. Structural equation modelling supported earlier results concerning male entrepreneurial activity. Personality and aspects of the parenting context the women had experienced by the average age of 12 predicted early entrepreneurial competencies (inventions, leadership) and occupational interests by age 13, which related to an entrepreneurship‐related career goal in 1936, when the participants were about 27 years of age on average. Such a career goal in turn predicted a higher number of occasions of entrepreneurship‐prone work. Surprisingly, we also found a relationship to divorce. Women who had experienced the failure of a marriage were in occupations with a potential for entrepreneurship more often. Reasons are discussed against a backdrop of historical timing and current findings to identify general aspects of entrepreneurship development.
Technological bias at the exchange rate market
Authors: Galeshchuk Svitlana
Published: July 2017

Prediction of exchange rates has been a topic for debate in economic literature since the late 1980s. The recent development of machine learning techniques has spurred a plethora of studies that further improves the prediction models for currency markets. This high‐tech progress may create challenges for market efficiency along with information asymmetry and irrationality of decision‐making. This technological bias emerges from the fact that recent innovative approaches have been used to solve trading tasks and to find the best trading strategies. This paper demonstrates that traders can leverage technological bias for financial market forecasting. Those traders who adapt faster to the changes in market innovations will get excess returns. To support this hypothesis we compare the performance of deep learning methods, shallow neural networks with baseline prediction methods and a random walk model using daily closing rate between three currency pairs: Euro and US Dollar (EUR/USD), British Pound and US Dollar (GBP/USD), and US Dollar and Japanese Yen (USD/JPY). The results demonstrate that deep learning achieves higher accuracy than alternate methods. The shallow neural network outperforms the random walk model, but cannot surpass ARIMA accuracy significantly. The paper discusses possible outcomes of the technological shift for financial market development and accounting conforming also to adaptive market hypothesis.
It's Complicated: Navigating Multiple Identities in Small Town America
Authors: Ferguson Angela D. , Miville Marie L.
Published: July 2017

During the past few years, research focused on individuals who identify as gay, lesbian, bisexual, and transgender (LGBT) have increased. However, much of this literature focuses on White LGBT individuals, and less on individuals who have intersected identities, such as being both gay/lesbian and a person of color. Consequently, this population becomes obscured in scholarly discourses, thus being made “invisible” with regard to theory, research, and clinical interventions, with the result that clinicians are provided little or no knowledge of theories or best practices when working with individuals who are both sexual minority and people of color. This article discusses an integrated theoretical and treatment process when working with clients who are navigating multiple oppressed identities.
Adsorptive filtration of low‐concentration lead with wet‐laid filter media made from nano‐TiO2 decorated cellulose fibers
Authors: Zhang Jinju , Li Lei , Li Yanxiang , Yang Chuanfang
Published: July 2017

Background

TiO2‐cellulose composite fibers are a new type of bio‐sorbent combining natural polymers and nanoparticles. However, their batch adsorption capacity is limited. Here mesoporous TiO2‐cellulose composite fibers were synthesized and a filter medium was subsequently made from them to remove lead continuously by dynamic adsorption.

Results

TiO2‐cellulose composite fibers with rough hierarchical surface structure were fabricated by in situ growing mesoporous TiO2 on cellulose fibers via microwave‐facilitated hydrolysis. The composite fibers were then wet‐laid into a filter medium to remove low‐concentration Pb2+ in water through adsorptive filtration. The breakthrough curves were found to be better predicted by the dose–response model originally established for a fixed column bed. With a volume of merely 2.07 cm3, the medium can treat 150.0 L of water containing 50 ppb lead to the drinking water standard. The filter performance was improved by incorporation of small non‐functional glass fibers to minimize the pore size and its distribution. The medium was also Pb2+ selective over co‐existing cations, and could be easily regenerated and reused without reduction in performance.

Conclusion

The filter medium fabricated by nano‐TiO2 decorated cellulose fibers showed enhanced adsorption capacity for lead through adsorptive filtration. Such filter beds have high potential for toxic micro‐pollutant removal from drinking water. © 2017 Society of Chemical Industry
Fluorescence spectroscopy coupled with independent components analysis to monitor molecular changes during heating and cooling of Cantal‐type cheeses with different NaCl and KCl contents
Authors: Loudiyi Mohammed , Karoui Romdhane , Rutledge Douglas N , Montel Marie‐Christine , Rifa Etienne , Aït‐Kaddour Abderrahmane
Published: July 2017

BACKGROUND

Reduction of NaCl content of cheeses has received considerable attention by research during the past decades because of its health effects. Nonetheless, NaCl reduction is a challenge since it plays an important role in cheese quality, such as structure, texture and functional properties. Several methods were used to evaluate the effect of NaCl on these attributes. In this study, Cantal‐type cheeses with different salts (NaCl and KCl) were analyzed for their structure at a molecular level and rheological properties during heating (20–60 °C) and cooling (60–20 °C). The structure was investigated by synchronous fluorescence spectroscopy (SFS) and the rheological properties by small‐amplitude oscillatory test.

RESULTS

Independent components analysis (ICA) gave three independent components that were attributed to coenzyme/Maillard reaction products (IC1), tryptophan (IC2) and vitamin A (IC3). Signal proportions of each IC depicted information regarding the changes in those fluorophores with salts, heating and cooling. In addition, canonical correlation analysis (CCA) of the IC proportions and rheological measurements related modifications at a molecular level evaluated by fluorescence to cheese texture (0.34 < R2 < 0.99).

CONCLUSION

This study demonstrated that SFS can monitor and characterize modification of Cantal‐type cheeses at a molecular level, based on the analysis of the fluorescence spectra by ICA. The nature of correlation between signal proportions and the rheological parameters depicted that rheological attributes of cheeses observed at the macroscopic level can be derived from fluorescence spectra. © 2017 Society of Chemical Industry
Functionalized superparamagnetic nanoparticles with a polymer containing β‐cyclodextrin for the extraction of sertraline hydrochloride in biological samples
Authors: Shamekhi Rahele , Ahmad Panahi Homayon , Alaei Haniyeh Sadat , Moniri Elham
Published: July 2017

In this study, a novel magnetic nanoadsorbent was synthesized by grafting β‐cyclodextrin onto the modified surface of Fe3O4 nanoparticles for the sorption and extraction of sertraline hydrochloride from human biological fluids. The extracted sertraline hydrochloride was measured by high‐performance liquid chromatography. The grafted nanosorbent was confirmed by Fourier transform infrared spectroscopy, transmission electron microscopy, thermogravimetric analysis, and elemental analysis. The kinetic sorption of sertraline hydrochloride by magnetic nanosorbent was 1 h. The best temperature for sorption of sertraline hydrochloride was at 25°C at an optimum pH of 5. The adsorbed sertraline hydrochloride can be desorbed by using methanol solution containing acetic acid (5%) and trifluoroacetic acid (1%).
Polymeric monolith column composited with multiwalled carbon nanotubes‐β‐cyclodextrin for the selective extraction of psoralen and isopsoralen
Authors: Ling Xu , Zou Li , Chen Zilin
Published: July 2017

A polymeric column that contains multiwalled carbon nanotubes‐β‐cyclodextrin composite was developed. The composite was wrapped into the poly(butyl methacrylate‐ethylene dimethacrylate) monolith column (0.76 mm id and 10 cm in length). The column was then applied for the online solid‐phase microextraction of psoralen and isopsoralen from Fructus Psoraleae. Following microextraction, the coumarins were quantified by high‐performance liquid chromatography with C18 separation column and UV detection. The effects of sample flow rate, sample volume, and pH value were optimized. The method showed low limits of detection (20 pg/mL, S/N = 3) for both psoralen and isopsoralen. Finally the method was successfully applied to the determination of psoralen and isopsoralen in spiked herb extracts and rat plasma where it gave recoveries that ranged between 93.2 and 102.1%. The empty hydrophobic cavities of β‐cyclodextrin and the hydrophobicity of multiwalled carbon nanotubes provided specific extraction capability for psoralen and isopsoralen.
The effect of film industry on tourism: Game of Thrones and Dubrovnik
Authors: Tkalec Marina , Zilic Ivan , Recher Vedran
Published: July 2017

Nowadays, there is competition in attracting film producers to screen their productions in specific locations, but at the same time, there is also a lack of data‐driven academic research that measures the effects of film industry on local tourism. This study evaluates the effects of film industry on tourism outcomes in Dubrovnik, Croatia. Using the synthetic control approach, we estimate the causal effect of a highly broadcasted TV series, Game of Thrones, on tourist arrivals. The use of such a data‐driven procedure is an important step towards identification‐based empirical work in tourism research as it enables us to build a credible synthetic counterfactual and to answer the “what if” type of questions. We find a robust and positive effect of filming the TV series in Dubrovnik on the number of tourist arrivals. Additionally, we show that there are positive spillover effects on other counties and the whole country. Placebo tests show that the estimated effects are relatively large when compared to other counties implying our results are not driven simply by chance.
Effects of industrial and investigator disturbance on Arctic‐nesting geese
Authors: Meixell Brandt W. , Flint Paul L.
Published: July 2017

Oil and gas development on the Arctic Coastal Plain (ACP) of Alaska, USA may have effects on Arctic‐nesting birds. To estimate effects of industrial activity and investigator disturbance on avian productivity, we monitored nests of greater white‐fronted geese (Anser albifrons) with digital cameras and periodic nest visits during 2013–2014 at 2 sites on the ACP. A disturbed site was adjacent to human‐made infrastructure and industrial clean‐up activities initiated at the onset of the study and a control site was >2 km from sources of industrial disturbance. We assessed variation in estimates of incubation constancy, nest survival, and predator behavior relative to site, year, and distance from industrial activity using nest photographs obtained at 1‐minute intervals. We compared analysis of hourly nest survival informed by intensive monitoring with cameras to analysis of daily nest survival informed by traditional nest visit data obtained at intervals of 5–7 days to assess how method and time scale of sampling affect ecological inference. Geese in both sites exhibited high levels of nest attendance and initiated incubation breaks less than once per day. Observer‐caused incubation breaks associated with nest visits ( = 37.8 min) were longer than other types of incubation breaks ( = 8.7 min), demonstrating a differential response by nesting geese to direct human encroachment versus indirect vehicular and aircraft traffic. During both years, geese were absent from nests more frequently in the disturbed ( = 0.9 breaks/day) than control ( = 0.6 breaks/day) site, and this break frequency was slightly higher for nests closer to industrial activity. In the year with high rates of depredation, nest survival was positively related to distance from industrial activity and abandoned infrastructure, consistent with predictions of industry‐caused effects. This relationship, however, was not evident in the year with reduced predation pressure, likely because of annual variation in arctic fox (Vulpes lagopus) behavior. Analysis of nest survival probability informed by camera data allowed for detection of detailed patterns of variation that were not supported when using only visit data for the same nests. Observer visits were responsible for reductions of 7–35% in nest survival probability, highlighting the importance of minimizing, and controlling for, observer effects in studies of avian productivity. Indirect vehicular and aircraft disturbance posed less risk to nest survival than direct encroachment by observers at nest sites. Therefore, effects of industrial activities on avian productivity in the Arctic can be minimized through practices that limit direct encounters with nests. Published 2017. This article is a U.S.Government work and is in the public domain in the USA.
Full‐night measurement of level of obstruction in sleep apnea utilizing continuous manometry
Authors: Jung Hahn Jin , Wee Jee Hye , Rhee Chae‐Seo , Kim Jeong‐Whun
Published: July 2017

Objectives/Hypothesis

To determine the average proportion of retropalatal or retroglossal obstruction occurring during a whole night in single patients with obstructive sleep apnea.

Study Design

Retrospective analysis.

Methods

Patients who underwent full‐night polysomnography and upper airway pressure manometry at the same time were retrospectively enrolled. Airway obstruction levels were categorized into retropalatal or retroglossal obstruction according to the pressure change shown during pressure manometry. The proportion of retropalatal/retroglossal obstruction was calculated for each patient. Independent factors associated with the proportion were assessed.

Results

A total of 218 patients (198 men) with obstructive sleep apnea were included in the study (mean age, 46.8 ± 1.6 years; body mass index, 26.7 ± 3.1 kg/m2). The average proportion of retroglossal and retropalatal obstruction in individuals was 36.2% and 63.8%, respectively. The apnea‐hypopnea index was not significantly correlated with the proportion of retroglossal obstruction (P = .219) after adjustment for age, sex, and body mass index. Meanwhile, the proportion of retroglossal obstruction was significantly correlated with oxygen desaturation index (P = .036), average oxygen saturation (P = .006), lowest oxygen saturation (P = .028), and time below 90% oxygen saturation (P = .021).

Conclusions

To our knowledge, this is the first study showing the average proportions of retropalatal/retroglossal obstruction occurring in single individuals with obstructive sleep apnea during a whole night. The proportion of upper airway obstruction site was significantly associated with oxygen desaturation.

Level of Evidence

4. Laryngoscope, 127:2897–2902, 2017
Safety and efficacy of functional laryngectomy for end‐stage dysphagia
Authors: Topf Michael C. , Magaña Linda C. , Salmon Kelly , Hamilton James , Keane William M. , Luginbuhl Adam , Curry Joseph M. , Cognetti David M. , Boon Maurits , Spiegel Joseph R.
Published: July 2017

Objectives/Hypothesis

To evaluate functional outcomes and complication rate after total laryngectomy (TL) for dysfunctional larynx with end‐stage dysphagia.

Study Design

Retrospective chart review.

Methods

Chart review was performed on all patients who underwent TL from January 2008 to July 2016 at a single tertiary academic medical center. Patients who underwent TL for dysfunctional larynx without preoperative evidence of malignancy were included. Main outcome measures were post‐TL functional swallowing and speech outcomes, and complication rate.

Results

The study included 19 patients from a cohort of 278 consecutive patients. All patients were previously treated with radiotherapy (RT), whereas 13/19 (68%) previously received chemoradiotherapy. The median time from RT to TL was 10.98 years (range, 0.67–23.94 years). Aspiration was evident preoperatively in 17/19 (89%) patients, with 11 experiencing recurrent aspiration pneumonia. Seventeen of 19 (89%) patients were nil per os (NPO) requiring enteral nutrition. Six of 19 (32%) patients had surgical complications, including three (16%) pharyngocutaneous fistulas. At 3‐month and 1‐year postoperative follow‐up, there was significant improvement in mean Functional Oral Intake Scale (FOIS) score and aspiration, recurrent pneumonia, enteral nutrition, and NPO status rates (P < .05). At 1‐year follow‐up, no patients were NPO, and only one patient required gastrostomy tube supplementation. Mean FOIS score increased from 1.3 to 6.1 (P = .001). Eight of 13 patients (62%) were actively using a tracheoesophageal prosthesis at 1‐year follow‐up.

Conclusions

Laryngectomy for dysfunctional larynx eliminates the morbidity of aspiration while improving diet and reducing gastrostomy tube dependence with an acceptable complication rate.

Level of Evidence

4. Laryngoscope, 128:597–602, 2018
Tidal modulation of seabed light and its implications for benthic algae
Authors: Roberts Emyr Martyn , Bowers David George , Davies Andrew John
Published: July 2017

The temporal behavior of seabed light in a shallow, tidal sea is set largely by the interaction of the solar elevation cycle with tidal cycles in water depth and temporal variability in water clarity. The effect of tidal modulation on seabed light often does not simply average out, producing instead a net effect (either an amplification or a reduction of seabed light, integrated over time) compared to a tideless, but otherwise equivalent, scenario. Observations of this phenomenon from the Bay of Brest (France) show reasonable agreement with predictions based on an earlier theoretical framework, confirming that the key physics has been understood and that the important parameters are tidal amplitude, timing of low waters, diffuse attenuation coefficient, and daylength. Implications for benthic macroalgae living in the bay's shallow subtidal zone are investigated using a simple numerical model. The effects of the tide on time‐integrated seabed light and, in turn, time‐integrated macroalgal community photosynthesis in the Bay of Brest correspond closely at three timescales: annual, springs‐neaps (i.e., approximately fortnightly), and daily. Tidal amplification of both parameters occurs over the year, during winter months generally, and at spring tides during winter specifically (slight reduction occurs at neaps during winter). For an individual, isolated thallus, the relationship between tidal modulation of seabed light and photosynthesis is complicated by more pronounced light‐saturation and photoinhibition effects. Demonstrated here for the first time, neglecting tidal effects on seabed light is likely to result in erroneous estimates (and, for many sites, underestimation) of subtidal benthic productivity.
Simple Radical Polymerization of Poly(Alginate‐Graft‐N‐Isopropylacrylamide) Injectable Thermoresponsive Hydrogel with the Potential for Localized and Sustained Delivery of Stem Cells and Bioactive Molecules
Authors: Pentlavalli Sreekanth , Chambers Philip , Sathy Binulal N. , O'Doherty Michelle , Chalanqui Marine , Kelly Daniel J. , Haut‐Donahue Tammy , McCarthy Helen O. , Dunne Nicholas J.
Published: July 2017

In this study, thermoresponsive copolymers that are fully injectable, biocompatible, and biodegradable and are synthesized via graft copolymerization of poly(N‐isopropylacrylamide) onto alginate using a free‐radical reaction are presented. This new synthesis method does not involve multisteps or associated toxicity issues, and has the potential to reduce scale‐up difficulties. Chemical and physical analyses verify the resultant graft copolymer structure. The lower critical solution temperature, which is a characteristic of sol–gel transition, is observed at 32 °C. The degradation properties indicate suitable degradation kinetics for drug delivery and bone tissue engineering applications. The synthesized P(Alg‐g‐NIPAAm) hydrogel is noncytotoxic with both human osteosarcoma (MG63) cells and porcine bone marrow derived mesenchymal stem cells (pBMSCs). pBMSCs encapsulated in the P(Alg‐g‐NIPAAm) hydrogel remain viable, show uniform distribution within the injected hydrogel, and undergo osteogenic and chondrogenic differentiation under appropriate culture conditions. Furthermore, for the first time, this work will explore the influence of alginate viscosity on the viscoelastic properties of the resulting copolymer hydrogels, which influences the rate of medical device formation and subsequent drug release. Together the results of this study indicate that the newly synthesized P(Alg‐g‐NIPAAm) hydrogel has potential to serve as a versatile and improved injectable platform for drug delivery and bone tissue engineering applications.
Codelivery for Paclitaxel and Bcl‐2 Conversion Gene by PHB‐PDMAEMA Amphiphilic Cationic Copolymer for Effective Drug Resistant Cancer Therapy
Authors: Wang Xiaoyuan , Liow Sing Shy , Wu Qiaoqiong , Li Chuang , Owh Cally , Li Zibiao , Loh Xian Jun , Wu Yun‐Long
Published: July 2017

Antiapoptotic Bcl‐2 protein's upregulated expression is a key reason for drug resistance leading to failure of chemotherapy. In this report, a series of biocompatible amphiphilic cationic poly[(R)‐3‐hydroxybutyrate] (PHB)‐b‐poly(2‐(dimethylamino)ethyl methacrylate) (PDMAEMA) copolymer, comprising hydrophobic PHB block and cationic PDMAEMA block, is designed to codeliver hydrophobic chemotherapeutic paclitaxel and Bcl‐2 converting gene Nur77/ΔDBD with enhanced stability, due to the micelle formation by hydrophobic PHB segment. This copolymer shows less toxicity but similar gene transfection efficiency to polyethyenimine (25k). More importantly, this codelivery approach by PHB‐PDMAEMA leads to increased drug resistant HepG2/Bcl‐2 cancer cell death, by increased expression of Nur77 proteins in the Bcl‐2 present intracellular mitochondria. This work signifies for the first time that cationic amphiphilic PHB‐b‐PDMAEMA copolymers can be utilized for the drug and gene codelivery to drug resistant cancer cells with high expression of antiapoptosis Bcl‐2 protein and the positive results are encouraging for the further design of codelivery platforms for combating drug resistant cancer cells.
Separation of Parent Homopolymers from Nonpolar Block Copolymers by Means of Liquid Chromatography under Limiting Conditions of Enthalpic Interactions
Authors: Berek Dušan
Published: July 2017

Parent homopolymers are baseline‐separated from the block copolymers with nonpolar arms in a single step with the help of liquid chromatography under limiting conditions of enthalpic interactions. The small differences in the chain solubility are employed to apparently originate two similar but independent liquid chromatography retention mechanisms, enthalpic partition (absorption) and phase separation (precipitation). For the first time, the option is demonstrated to separate a complex polymer system with a tandem of two independent liquid chromatography procedures.
Nanocomposites of Polymeric Biomaterials Containing Carbonate Groups: An Overview
Authors: Taraghi Iman , Paszkiewicz Sandra , Grebowicz Janusz , Fereidoon Abdolhossein , Roslaniec Zbigniew
Published: July 2017

The modification of biomaterials using nanoadditives can lead to the development of novel materials for a wide variety of biomedical applications such as drug administration systems, tissue engineering, bioresistance coatings, and biomedical instruments. Moreover, a further improvement of mechanical and thermal properties of aforementioned biomaterials while maintaining their dimensional stability is a goal of major scientific researches. Aliphatic polycarbonates (APCs) containing carbonate groups such as poly(trimethylene carbonate), poly(propylene carbonate), poly(ethylene carbonate), poly(dimethyl trimethylene carbonate), etc., have become much more interesting compared to other biodegradable materials due to their unique physical and chemical properties. This review presents the effect of applying different kinds of nanoparticles (NPs) on the mechanical, thermal, and viscoelastic properties as well as dimensional stability and biocompatibility of APCs. The dispersion process of nanofillers within polymer matrices has been divided into two groups, solution and melt mixing techniques. Moreover, synthesis procedures of APC loaded NPs for drug delivery systems and electrospinning of nanofiber mats have also been reviewed. In order to clarify the effect of NPs on the overall characteristics of the APC biomaterials, the detailed mechanism of improving process have been extensively discussed.
Enhancing methyl parathion degradation by the immobilization of Burkholderia sp. isolated from agricultural soils
Authors: Fernández‐López Maikel Gilberto , Popoca‐Ursino Carolina , Sánchez‐Salinas Enrique , Tinoco‐Valencia Raunel , Folch‐Mallol Jorge Luis , Dantán‐González Edgar , Laura Ortiz‐Hernández Ma
Published: July 2017

Organophosphate pesticides are of great interest for research because they are currently the most commonly used pesticides. In this study, a bacterial strain capable of completely degrading methyl parathion (MP) was isolated from agricultural soils in central Mexico. This strain was designated strain S5‐2 and was identified as Burkholderia cenocepacia. To increase degradation yields, cells were immobilized on three different supports: powdered zeolite and Opuntia sp. and Agave sp. fibers. The results indicated a significant increase in MP hydrolysis and p‐nitrophenol (PNP) degradation with immobilized cells compared to free cell cultures. Furthermore, immobilized cells were capable of withstanding and degrading higher concentrations of PNP compared to cell suspension cultures. The cell viability in the free cell cultures, as well as PNP degradation, was affected at concentrations greater than 25 mg/L. In contrast, cells immobilized on Opuntia sp. and Agave sp. fibers completely degraded PNP at concentrations of 100 mg/L. To verify that MP solution toxicity was decreased by B. cenocepacia strain S5‐2 via pesticide degradation, we measured the acetylcholinesterase activity, both before and after treatment with bacteria. The results demonstrate that the activity of acetylcholinesterase was unaffected after MP degradation by bacteria.
Generalized Bessel functions: Theory and their applications
Authors: Khosravian‐Arab Hassan , Dehghan Mehdi , Eslahchi M. R.
Published: July 2017

This paper presents 2 new classes of the Bessel functions on a compact domain [0,T] as generalized‐tempered Bessel functions of the first‐ and second‐kind which are denoted by GTBFs‐1 and GTBFs‐2. Two special cases corresponding to the GTBFs‐1 and GTBFs‐2 are considered. We first prove that these functions are as the solutions of 2 linear differential operators and then show that these operators are self‐adjoint on suitable domains. Some interesting properties of these sets of functions such as orthogonality, completeness, fractional derivatives and integrals, recursive relations, asymptotic formulas, and so on are proved in detail. Finally, these functions are performed to approximate some functions and also to solve 3 practical differential equations of fractionalorders.
Technical Note: Evaluation of plastic scintillator detector for small field stereotactic patient‐specific quality assurance
Authors: Qin Yujiao , Gardner Stephen J. , Kim Joshua , Huang Yimei , Wen Ning , Doemer Anthony , Chetty Indrin J.
Published: July 2017

Purpose

To evaluate the performance of a commercial plastic scintillator detector (PSD) for small‐field stereotactic patient‐specific quality assurance (QA) measurements using flattening‐filter‐free beam.

Methods

A total of 10 spherical targets [volume range: (0.03 cc–2 cc)] were planned with two techniques: (a) dynamic conformal arc (DCA‐10 plans) and (b) volumetric modulated arc therapy (VMAT‐10 plans). All plans were generated using Varian Eclipse treatment planning system, and AcurosXB v.13 algorithm in 1.0 mm grid size. Additionally, 14 previously treated cranial and spine SRS plans were evaluated [6 DCA, 8 VMAT, volume range: (0.04 cc–119.02 cc)]. Plan modulation was quantified via two metrics: MU per prescription dose (MU/Rx) and Average Leaf Pair Opening (ALPO). QA was performed on the Varian Edge linear accelerator equipped with HDMLC. Three detectors were used: (a) PinPoint ion chamber (PTW; active volume 0.015 cc), (b) Exradin W1 PSD (Standard Imaging; active volume 0.002 cc), and (c) Gafchromic EBT3 film (Ashland). PinPoint chamber and PSD were positioned perpendicular to beam axis in a Lucy phantom (Standard Imaging); films were placed horizontally capturing the coronal plane.

Results

PSD, film, and PinPoint chamber measured average differences of 1.00 ± 1.54%, 1.30 ± 1.69%, and −0.66 ± 2.36%, respectively, compared to AcurosXB dose calculation. As the target volume decreased, PinPoint chamber measured lower doses (maximum −5.07% at 0.07 cc target), while PSD and film measured higher doses (2.87% and 2.54% at 0.03 cc target) than AcurosXB. Film agreed with the benchmark detector PSD by an average difference of 0.31 ± 1.20%, but suffered from larger uncertainty; PinPoint chamber underestimated dose by more than 4% for targets smaller than 0.2 cc. Taking PSD as the measurement standard, DCA plans achieved good QA results across all volumes studied, with an average of −0.07 ± 0.89%; for VMAT plans, PSD measured consistently higher dose (1.95 ± 1.36%) than AcurosXB. Correlation study revealed that plan modulation quantified by both MU/Rx and ALPO correlated significantly with QA results.

Conclusion

Among all three detectors, PSD demonstrated superior performances in plans with small fields and heavy modulation. High consistency and low uncertainty made PSD a suitable detector for clinical routine SRS QA. PinPoint chamber should be avoided for targets smaller than 0.2 cc; film dosimetry can be utilized with careful evaluation of its uncertainty bracket. Compared to PSD measurements, AcurosXB calculation demonstrated high accuracy for nonmodulated small fields. The positive correlation between plan modulation and QA discrepancy calls for our attention for clinical SRS plans with high modulation.
Assessing the validity of the approximation of diffusion‐weighted‐MRI signals from crossing fascicles by sums of signals from single fascicles
Authors: Rensonnet Gaëtan , Scherrer Benoît , Warfield Simon K. , Macq Benoît , Taquet Maxime
Published: July 2017

Purpose

To assess the validity of the superposition approximation for crossing fascicles, i.e., the assumption that the total diffusion‐weighted MRI signal is the sum of the signals arising from each fascicle independently, even when the fascicles intermingle in a voxel.

Methods

Monte Carlo simulations were used to study the impact of the approximation on the diffusion‐weighted MRI signal and to assess whether this approximate model allows microstructural features of interwoven fascicles to be accurately estimated, despite signal differences.

Results

Small normalized signal differences were observed, typically
. The use of the approximation had little impact on the estimation of the crossing angle, the axonal density index, and the radius index in clinically realistic scenarios wherein the acquisition noise was the predominant source of errors. In the absence of noise, large systematic errors due to the superposition approximation only persisted for the radius index, mainly driven by a low sensitivity of diffusion‐weighted MRI signals to small radii in general.

Conclusion

The use of the superposition approximation rather than a model of interwoven fascicles does not adversely impact the estimation of microstructural features of interwoven fascicles in most current clinical settings. Magn Reson Med 79:2332–2345, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Simultaneous magnetic resonance diffusion and pseudo‐diffusion tensor imaging
Authors: Mozumder Meghdoot , Beltrachini Leandro , Collier Quinten , Pozo Jose M. , Frangi Alejandro F.
Published: July 2017

Purpose

An emerging topic in diffusion magnetic resonance is imaging blood microcirculation alongside water diffusion using the intravoxel incoherent motion (IVIM) model. Recently, a combined IVIM diffusion tensor imaging (IVIM‐DTI) model was proposed, which accounts for both anisotropic pseudo‐diffusion due to blood microcirculation and anisotropic diffusion due to tissue microstructures. In this article, we propose a robust IVIM‐DTI approach for simultaneous diffusion and pseudo‐diffusion tensor imaging.

Methods

Conventional IVIM estimation methods can be broadly divided into two‐step (diffusion and pseudo‐diffusion estimated separately) and one‐step (diffusion and pseudo‐diffusion estimated simultaneously) methods. Here, both methods were applied on the IVIM‐DTI model. An improved one‐step method based on damped Gauss–Newton algorithm and a Gaussian prior for the model parameters was also introduced. The sensitivities of these methods to different parameter initializations were tested with realistic in silico simulations and experimental in vivo data.

Results

The one‐step damped Gauss–Newton method with a Gaussian prior was less sensitive to noise and the choice of initial parameters and delivered more accurate estimates of IVIM‐DTI parameters compared to the other methods.

Conclusion

One‐step estimation using damped Gauss–Newton and a Gaussian prior is a robust method for simultaneous diffusion and pseudo‐diffusion tensor imaging using IVIM‐DTI model. Magn Reson Med 79:2367–2378, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.