bluuebunny/crossref_metadata_2025 huggingface dataset:
Snow cover duration and extent for Great Britain in a changing climate: Altitudinal variations and synoptic‐scale influences
Authors: Brown Iain
Published: April 2019

Snow cover is an important indicator of climate change but constraints on observational data quality can limit interpretation of spatial and temporal variability, especially in mountain areas. This issue was addressed using archived data from the Snow Survey of Great Britain to infer key climate relationships which were then used to reference larger‐scale patterns of change. Data analysis using nonlinear (logistic) regression showed average changes in yearly snow cover were strongly related to mean temperature rather than precipitation values. Inferred change shows long‐term decline in average yearly snow cover with greatest declines in some mountain areas, notably in northern England, that can be related to their position on the most temperature‐sensitive segment of the logistic curve. Further declines in snow cover were projected in the future: a central ensemble projection from HadRM3 climate model showed average yearly snow cover predominantly confined to Great Britain mountain areas by the 2050s. However, inter‐annual variability means some years can deviate significantly from average snow cover patterns. Site‐based analysis showed this variability has distinctive geographical variations and different influences for mountains compared to adjacent valleys. Comparison of inter‐annual variability with Lamb weather‐type frequency and North Atlantic Oscillation index shows the influence of large‐scale airflow patterns on snow cover duration. Most notable is the role of northwesterly and northerly flows in explaining snowy years on mountains exposed to that direction, compared to influence of easterly flows at lower levels. Future changes will therefore depend on dominant annual/decadal circulation patterns in addition to long‐term declines from climate warming.
A conceptually superior variant of Shepard's method with modified neighbourhood selection for precipitation interpolation
Authors: Yeggina Subash , Teegavarapu Ramesh S. V. , Muddu Sekhar
Published: April 2019

The accuracy of gridded precipitation data depends on the availability of a uniformly spaced rain gauge network and an appropriate spatial interpolation method that considers the rainfall variability and other factors that influence the precipitation patterns in the region of interest. In the current study, conceptually superior variants of a widely used spatial interpolation algorithm, Shepard's method, are proposed, formulated and evaluated to overcome one of the major limitations in neighbourhood selection, that is, arbitrary selection of rain gauges. The variants provide mechanisms to objectively select the rain gauges (control points) based on correlation (variant 1), distribution similarity (variant 2) and a combination of both (variant 3). The improved variants were used in the development of gridded rainfall data at a resolution of 5 km over the Kabini River basin in south India, and in the state of Kentucky, United States. Results from multiple experiments using the original Shepard's method and its variants indicate improvements in the accuracy of precipitation estimates. Also, these variants have preserved the site‐specific statistics and distributional characteristics of the rainfall data. A variant 1 that uses a correlation‐based neighbourhood selection criterion performed better for daily and monthly data compared to others and is suitable for generation of gridded rainfall data. The variant 1 when used with information from clustering of sites for selection of the neighbours has led to improvement in gridded precipitation data estimates. The proposed variant 1 can also be used for point data estimation useful for filling missing data at any site.
Various characteristics of precipitation concentration index and its cause analysis in China between 1960 and 2016
Authors: Zhang Kexin , Yao Yulong , Qian Xiaoqing , Wang Juanjuan
Published: April 2019

The precipitation concentration index (PCI) is a powerful indicator for temporal precipitation distribution and is also very useful for the assessment of seasonal precipitation changes. The primary objectives of this study are to investigate and analyse the temporal–spatial variability patterns of annual and seasonal PCI values based on monthly precipitation data. These data were collected from 597 meteorological stations located throughout China, for the time period of 1960–2016, and were used to assess the impacts of geographical parameters (latitude, longitude, and altitude) on the PCI. Additionally, the possible teleconnection with the large‐scale circulation pattern was investigated. Our results reveal that the variation trend of annual PCI values has decreased significantly at a rate of −.234/10 year (α = .01) in China over the past 57 years. For all studied station records, 434 (72.7%) stations showed decreasing trends of PCI values, and these stations are distributed over large areas in China. On an annual scale, the average PCI value ranged from 11 in Hunan province to 44 in Qinghai province. The precipitation concentration in China can be described as strongly irregular in the western and northern parts of the northwest and in the northern region of the Tibetan Plateau, while it is irregular in the southwest and the north of China, and moderately irregular in some parts of the middle‐lower regions of the Yangtze River and southern China. The regularity of the annual precipitation pattern significantly decreased in spring, autumn, and winter from southeastern to northwestern China, and was the most in winter. However, the summer precipitation dispersion and the pattern in the considered period were more regular than those of the other seasons. Furthermore, changes in the PCI appear to be rather complex and possibly related to global atmospheric characteristics as well as geographical factors (latitude, longitude, and altitude). The results presented in this study indicate that the PCI is an essential feature for water resource planning, prediction of risk due to droughts or floods, and the management of natural resources.
Characterization of temperature difference between the neighbouring days in China and its potential driving factors
Authors: Tian Peipei , Lu Hongwei , Xue Yuxuan
Published: April 2019

Understanding the temperature difference between neighbouring days (TDN) is beneficial for reducing the harmful impacts of sudden temperature changes on human health and establishing adaptation policies considering global TDN characteristics. This study analyses the spatiotemporal characteristics of TDN in Mainland China on the basis of the daily observation data from 839 stations in 1961–2017. Results show that the TDN increases with the latitude from south to north. Meanwhile, TDN in winter is higher but lower in summer. These characteristics potentially arise from the variations in solar elevation angle, that is, a decreased TDN corresponds to an increased solar elevation angle in most parts of China. Areas with high solar elevation angle are usually characterized by low TDN, which implies that temperature is stable for neighbouring days in areas with high solar elevation angle. Moreover, the variation rate of the annual mean TDN is negative in most parts of China, especially in the north. These findings are expected to provide an overview of the spatiotemporal characteristics of TDN and support future studies on the impacts of TDN variations on regional environmental changes.
Emergency department resilience to disaster‐level overcrowding: A component resilience framework for analysis and predictive modeling
Authors: Davis Zachary , Zobel Christopher W. , Khansa Lara , Glick Roger E.
Published: April 2019

Overcrowding poses a serious challenge to the operations of health care facilities, especially those with a mandate to provide emergency care. A better understanding of emergency department (ED) performance during disaster‐level overcrowding is a key to increasing a facility's resilience, optimizing patient outcomes, and more effectively allocating resources. With this in mind, this study quantitatively examines the extent to which different factors contribute to the resilience of hospital EDs during disaster‐level overcrowding events. A modeling framework was developed in collaboration with the Carilion Clinic ED, a level one trauma center in Virginia. The testing and analysis of the approach is based on data from actual disaster‐level overcrowding events that occurred in the Spring of 2016. Results indicate that by considering not only the capacity for resisting such events but also the capacity for recovering from them more quickly, hospital decision makers can improve both their operational effectiveness and the patient experience. Furthermore, by using our framework to identify precipitating factors and predict severe overcrowding, hospital decision makers can implement changes to improve the future resilience of their ED to such overcrowding events.
Operational efficiency and patient‐centered health care: A view from online physician reviews
Authors: Ko Dong‐Gil , Mai Feng , Shan Zhe , Zhang Dawei
Published: April 2019

Online reviews are playing an increasingly important role in how patients select and evaluate health‐care providers. Physician rating websites not only act as open platforms for patients to share their experiences, but can also offer valuable feedback for physicians to improve the quality of care. In this study, we analyze over one million physician reviews across 17 medical specialties and investigate the relationship between operational efficiency and patient satisfaction. We combine econometrics models with text analytics techniques to quantify the effect using both patients' ratings of physicians and their qualitative review narratives. The results provide strong empirical evidence that operational inefficiency negatively influences patient satisfaction. Specifically, a waiting time longer than 17 min will, on average, reduce the odds of getting a high rating status by 14%. Though many health care ratings examined in this study do not mitigate the negative effects brought on by long waiting time, patient narratives reflecting the importance of technical and interpersonal qualities to patients suggest a more complex set of relationships between waiting time and patient satisfaction. Our study showcases the usefulness of online physician reviews and reveals unique insights for improving the delivery of patient‐centered health care.
Interest in orthodontic tooth alignment in adult patients affected by periodontitis: A questionnaire‐based cross‐sectional pilot study
Authors: Hirschfeld Josefine , Reichardt Elisabeth , Sharma Praveen , Hilber Anna , Meyer‐Marcotty Philipp , Stellzig‐Eisenhauer Angelika , Schlagenhauf Ulrich , Sickel Franka E.
Published: April 2019

Background

Orthodontic treatment can successfully align pathologically migrated teeth and lead to improvement of periodontal stability in patients with periodontitis. Periodontic‐orthodontic approaches have gained increasing attention in the past years. Here, we investigated the interest of adults affected by chronic periodontitis in undergoing orthodontic treatment as well as patient‐related and tooth‐related influence factors.

Methods

Periodontal and orthodontic measurements/indices were taken from 115 adult patients with moderate‐to‐severe periodontitis. The study participants answered a questionnaire investigating patient demographics, quality of life aspects, and their interest in undergoing orthodontic treatment. Correlations between clinical data, questionnaire responses, and this interest were analyzed by means of an age‐ and sex‐adjusted multiple regression model.

Results

Two‐thirds of the participants were interested in orthodontic therapy and indicated long‐term healthy and esthetically appealing teeth as their main motives. A significant correlation was found between subjectively felt impaired dental esthetics and an interest in orthodontic treatment. However, there were no correlations with the severity of periodontitis, tooth alignment, or patient demographics, including sex. Older patients were significantly more often interested in orthodontic treatment. Most participants had never been provided with information about orthodontic treatment options for adults.

Conclusions

A considerable number of adult patients with periodontitis were interested in orthodontics to improve tooth alignment. However, severity of periodontitis and tooth misalignment or demographic factors may not be indicative thereof. Therefore, dental practitioners need to be aware of patients wishing to align their teeth and to provide them with the relevant information and, if appropriate, enable interdisciplinary treatment planning.
Characterization of supercontinuum generation in a photonic crystal fiber for uses in multiplex CARS microspectroscopy
Authors: Falconieri Mauro , Marrocco Michele , Merla Caterina , Gagliardi Serena , Rondino Flaminia , Ghezelbash Mahsa
Published: April 2019

Coherent anti‐Stokes Raman scattering (CARS) is a versatile technique for vibrational imaging that can be realized by a simple setup using a single femtosecond laser oscillator. For such a layout, supercontinuum generation in a photonic crystal fiber (PCF) is commonly used to produce a broadband Stokes beam in the so‐called multiplex CARS spectroscopy; accordingly, characterization of the supercontinuum beam is a necessary requirement to perform controlled experiments. In this paper, we first perform simulations and characterizations of the supercontinuum spectra produced by a PCF in conditions encountered in a typical single‐oscillator multiplex CARS setup. Good agreement between the experimental and simulated supercontinuum spectra is obtained in the whole emission band and for different PCF working conditions, by accurate choice of the simulation input parameters and by accounting for the input beam chirp in the numerical code. The influence of PCF working conditions on the CARS signal measured on a reference sample is also shown. To this regard, we also study the long‐term stability of the Stokes beam and of the associated CARS signal, using the Allan variance to determine a limit to the acquisition time in CARS measurements. We show that Stokes and CARS long‐term spectral fluctuations are on a timescale of some minutes in our setup, setting an indicative limit to the practical acquisition time for reliable CARS measurements. Based on this work, good control over the measurement of vibrational bands by CARS microscopy can be achieved in view of optimized performances in specific spectral bands.
Raman spectroscopy for the discrimination and quantification of fuel blends
Authors: Liu Zhe , Luo Ningning , Shi Jiulin , Zhang Yubao , Xie Chengfeng , Zhang Weiwei , Wang Hongpeng , He Xingdao , Chen Zhongping
Published: April 2019

Biodiesel is an alternative energy source to replace fossil fuels and reduce the environmental pollution. Adding biodiesel in fossil diesel can increase the oxygen content (from fatty acid) and promote fuel to be burned more quickly and thoroughly. However, the biodiesel content criterion of different countries was diverse from each other. In this study, Raman spectroscopy was used as a tool in classifying fuel blends and quantifying biodiesel contents. For classifying the fuel blends, principal component analysis (PCA) method was employed, where 87.22% of spectral variation was characterized by the first two components PCA scores shows a clear discrimination between the pure fuels and mixture fuels. Meanwhile, for identifying and quantifying the blends of diesel and biodiesel, Raman spectroscopy analysis based on partial least squares (PLS) regression was conducted. Biodiesel mainly present three characteristic Raman regions corresponding to the spectroscopy of diesel. The C─H Raman region presents the better quantitative capacity than the C═C and C═O spectral regions. And the PLS regression built from C─H Raman spectral region in quantifying biodiesel contents presents a higher correlation coefficient and lower root mean square error for prediction. Furthermore, employing only C─H Raman region coupled with PLS regression for predicting concentration of biodiesel can reduce an order of magnitude of root mean square error compared with using three characteristic Raman spectral regions together. Our result show that Raman spectroscopy combined with PCA and PLS can identify fuels and biofuels for discrimination and quantitation.
Differentiation of avocados according to their botanical variety using liquid chromatographic fingerprinting and multivariate classification tree
Authors: Martín‐Torres Sandra , Jiménez‐Carvelo Ana M , González‐Casado Antonio , Cuadros‐Rodríguez Luis
Published: April 2019

Background

The oil content, composition and marketing threshold value of an avocado depends on the cultivar hence, identifying the cultivar of the avocado fruit is desirable. However, analytical methods have not been reported with this aim.

Results

A multivariate classification tree method was proposed to discriminate three commercial botanical varieties of avocado: Hass, Fuerte and Bacon, using high‐performance liquid chromatography coupled to a charged aerosol detector (HPLC‐CAD). Prior to the chromatographic analysis the avocados were lyophilized and then the oil fraction was extracted using a pressurized liquid extraction system. Normal and reverse phase liquid chromatography were applied in order to obtain the chromatographic fingerprint for each sample.

Soft independent modelling of class analogies (SIMCA) and partial least‐squares discriminant analysis (PLS‐DA) were applied. Classification quality metrics were determined to evaluate the performance of the classification. Several strategies to develop the classification models were employed. Finally, the useful application of ‘classification trees’ methodology, which has been scarcely applied in the field of analytical food control, was evaluated to perform a multiclass classification.

Conclusion

Discrimination of the three botanical varieties was achieved. The best classification was obtained when the PLS‐DA is applied on the normal‐phase chromatographic fingerprints. Classification trees are showed to be useful tools that provide complementary information to single concatenated models showing different results from the same prediction sample set. © 2019 Society of Chemical Industry
Improved structure‐stability and packaging characters of crosslinked collagen fiber‐based film with casein, keratin and SPI
Authors: Wu Xiaomeng , Luo Yanghe , Liu Qi , Jiang Shujuan , Mu Guangqing
Published: April 2019

Background

To improve the structure‐stability and packing characters of collagen fiber, we manufactured crosslinked collagen fiber (CColF)‐based edible films using transglutaminase (TGase). Then we made a comparison on structure‐stability and packing characteristics among the CColF‐based films loaded with casein (CN), keratin (KRT) and soy protein isolate (SPI), respectively.

Results

Observed from scanning electron microscopy (SEM), the CColF loaded with CN, KRT and SPI showed some unique morphology of the additional proteins. The CColF–protein films performed better packing characteristics including barrier properties, mechanical properties and thermal‐stability properties, compared with CColF films. Importantly, with 500 g kg−1CN (of CColF) addition, CColF‐based films possessed a greater thermal stability than the other films judged from differential scanning calorimetry (DSC). Meanwhile, the CColF loaded with 100 g kg−1CN provided a higher value of tensile strength (TS) and the CColF loaded with 100 g kg−1KRT showed a higher value in elongation‐at‐break (EAB) than the other films.

Conclusion

In conclusion, the collagen fiber‐based edible films with better structure‐stability and packing characteristics for food packaging was obtained which could be an advantage to promote the development of the application of collagen in packing products. © 2019 Society of Chemical Industry
Low intake of digestible carbohydrates ameliorates duodenal absorption of carbohydrates in mice with glucose metabolism disorders induced by artificial sweeteners
Authors: Shi Qing , Cai Lei , Jia Hongzhe , Zhu Xuemei , Chen Lei , Deng Shaoping
Published: April 2019

Background

Long‐term artificial sweetener consumption has been reported to induce glucose intolerance, and the intestinal microbiota seems as an important target. While the impacts of artificial sweeteners on energy balance remain controversial, this work aimed to evaluate the protective effects in mice of a low digestible carbohydrate (LDC) diet on plasma glucose, plasma fasting insulin, sweet taste receptors, glucose transporters, and absorption of carbohydrates, together with consumption of acesulfame potassium (AK) or saccharin (SAC).

Results

Artificial sweetener was administered to mice for 12 weeks to induce glucose metabolism disorders; mice were treated with an LDC diet for the final 6 weeks. The experimental groups were treated with an LDC diet that had the same energy as the normal‐diet group. Prolonged administration of artificial sweeteners led to metabolic dysfunction, characterized by significantly increased plasma glucose, insulin resistance, sweet taste receptors, glucose transporters, and absorption of carbohydrates. Treatment with an LDC diet positively modulated these altered parameters, suggesting overall beneficial effects of an LDC diet on detrimental changes associated with artificial sweeteners.

Conclusions

Reducing digestible carbohydrates in the diet can significantly reduce the absorption of carbohydrates and improve glucose metabolism disorders caused by dietary factors. These effects may be due to the fact that reducing the amount of digestible carbohydrates in the feed can reduce the number of intestinal sweet receptors induced by exposure to artificial sweeteners. © 2019 Society of Chemical Industry
Effects of sodium alginate‐based coating pretreatment on drying characteristics and quality of heat pump dried scallop adductors
Authors: Shi Qilong , Tian Yuan , Zhu Lanlan , Zhao Ya
Published: April 2019

Background

Drying efficiency and quality maintenance are the major concerns of both manufactures and consumers. Heat pump drying (HPD) is suitable for heat sensitive foodstuffs due to its ability to independently control the drying operation parameters. However, lower drying rate and energy efficiency in the later period of HPD are the bottlenecks that restrain its application. A novel approach using hydrocolloids as pretreatment coatings prior to drying was designed to solve these problems. The effects of sodium alginate (SA) coating, drying temperatures and air velocities on the drying characteristics and quality attributes of scallop adductors were evaluated.

Results

Drying took place in the falling rate period. Drying time decreased with increasing temperature, air velocity and SA coating. The Two Term model and the Wang and Singh model gained the best fit for thin‐layer drying of scallop adductors and SA film, respectively. Effective moisture diffusivity increased with temperature, velocity and SA coating and were in the range 7.352–14.620 × 10−11, 9.890–17.100 × 10−11 and 2.348–4.604 × 10−10 m2 s−1 for uncoated scallop adductors, SA coated scallop adductors and SA films, respectively. The activation energies for SA films, coated and uncoated scallop adductors were 17.07, 20.78 and 26.17 kJ mol−1, respectively. Dried scallop adductors with SA coating pretreatment exhibited a significant lower value of shrinkage rate and hardness, and higher value of toughness than uncoated ones at 30 °C and 2.0 m s−1 (P < 0.05).

Conclusion

Hydrocolloid coating is a promising pretreatment in improving HPD efficiency and enhancing quality attributes of dried scallop adductors. © 2019 Society of Chemical Industry
Chromatographic determination of biogenic amines in four typical Italian cheeses: correlations with processing and nutritional characteristics through a chemometric approach
Authors: Rivoira Luca , Castiglioni Michele , Bruzzoniti Maria Concetta
Published: April 2019

BACKGROUND

The presence of biogenic amines (BAs) fermented food is well known. They may affect food quality, posing health risks.

In this work, four typical Italian cheeses, exported worldwide, were analyzed to determine the possible presence of BAs. The cheese samples were analyzed untreated and having been subjected to common or incorrect consumer handling (domestic grating, unrefrigerated storage).

RESULTS

A chromatographic‐amperometric method was developed and validated. Extraction of BAs was performed by the addition of eluent, determining matrix effect and recovery of biogenic amines directly within the cheeses.

Biogenic amines were present in the range of 0.019–0.044 g kg−1, well below the current EU limit. Home‐manipulation confirmed recontamination of the cheese. The contents of BAs were correlated with the main processing parameters and with the nutritional properties of the four cheeses through the multivariate statistical analysis (principal component analysis). This is believed to be the first study that presents these correlations.

CONCLUSION

This study highlights correlations among BAs and carbohydrates, and anticorrelations with pH and, to a lesser extent, with moisture. Interestingly, BAs are correlated with fat content. This correlation was confirmed by a new principal component analysis performed on our data set with additional data from the literature. © 2019 Society of Chemical Industry
Microlense liquid crystal devices on the base of cylindrical objects
Authors: Belyaev Victor V. , Solomatin Alexey S. , Suarez Douglas R. , Margaryan Hakob , Hakobyan Nune , Smirnov Alexander G.
Published: April 2019

Liquid crystal (LC) director and refractive index distribution in a cylindrical object (eg, micropore) with different LC boundary conditions have been simulated. Splay and bend configurations were simulated in the LC pores with Franck elastic coefficients K33/K11 ratio from 0.5 to 3. For different LC orientation configurations, parabolic profiles of radial dependence of the refractive index are obtained with focus distance up to 80 mm that makes it possible for application in different LC devices.
Preoperative risk evaluation for pancreatic fistula after pancreaticoduodenectomy
Authors: Ellis Ryan J. , Brock Hewitt D. , Liu Jason B. , Cohen Mark E. , Merkow Ryan P. , Bentrem David J. , Bilimoria Karl Y. , Yang Anthony D.
Published: April 2019

Background

Pancreatic fistula remains common, with limited ability to risk stratify patients preoperatively. The objective of this study was to identify risk factors for clinically‐relevant postoperative pancreatic fistula (CR‐POPF) that are routinely available in the preoperative setting.

Methods

Preoperatively available variables for all pancreaticoduodenectomies from 2014‐2017 were examined using a national clinical registry. The cohort was separated into risk factor identification and internal validation subgroups.

Results

Among 15 033 pancreaticoduodenectomies, the CR‐POPF rate was 16.7%. CR‐POPF was more likely in patients that were male (odds ratio [OR], 1.51), obese (body mass index [BMI] > 30, OR, 1.97), had minimal preoperative weight loss (OR, 1.25), had a nondilated pancreatic duct (OR, 1.81), did not have diabetes, (OR, 1.80), did not receive neoadjuvant therapy (OR, 1.78), had no evidence of biliary obstruction (OR, 1.18), or had nonadenocarcinoma pathology (OR, 1.96; all P < 0.01). Patients with three or fewer risk factors had a CR‐POPF rate of 7.1%, while those with six or more risk factors had a CR‐POPF rate of 26.3% (P < 0.001).

Conclusion

Preoperative CR‐POPF risk evaluation could be a useful tool in patient counseling and surgical planning, and risk may allow for more well‐informed decisions regarding perioperative management, including enhanced recovery protocols and use of somatostatin analogs.
Separation and purification of lanosterol, dihydrolanosterol, and cholesterol from lanolin by high‐performance counter‐current chromatography dual‐mode elution method
Authors: Pei Hairun , Ma Xiaotong , Pan Yan , Han Tian , Lu Zhifang , Wu Ruijuan , Cao Xueli , Zheng Jimin
Published: April 2019

Lanosterol is a potential drug for cataracts treatment, which can reverse the aggregation of intracrystalline proteins. The low concentration in lanolin calls for high‐performance separation methods. In this study, a counter‐current chromatography dual‐mode elution method was developed for the first time to separate and purify lanosterol from hexane extract of lanolin after saponification, in which the column was first eluted with the lower phase as mobile phase in head‐to‐tail mode, followed by the upper phase in the tail‐to‐head mode. High purity of lanosterol, dihydrolanosterol, and cholesterol can be obtained simultaneously. A solvent system composed of n‐heptane/acetonitrile/ethyl acetate (5:5:1, v/v/v) was selected and optimized via partition coefficient determination. Compounds such as 111 mg lanosterol, 84 mg dihydrolanosterol, and 183 mg cholesterol with high purity of 99.77, 95.71, and 91.43%, respectively, analyzed by high‐performance liquid chromatography were obtained within 80 min from 700 mg crude extract from 1.78 g lanolin. The method was also used to improve the purity of commercial lanosterol product from 66.97 to above 99%. Counter‐current chromatography could serve as a potential and powerful technique for commercial production of highly pure lanosterol.
Survival and cause‐specific mortality of moose calves in Northeastern Minnesota
Authors: Severud William J. , Obermoller Tyler R. , Delgiudice Glenn D. , Fieberg John R.
Published: April 2019

Ungulate reproductive success (calf production and survival) influences population performance. The moose (Alces alces) population in northeastern Minnesota, USA, has declined 65% from 2006 to 2018 but has begun to stabilize. Because causes of this decline were largely unknown, we investigated production, survival, and cause‐specific mortality of calves of the global positioning system (GPS)‐collared females in this population. In 2013 and 2014, we GPS‐collared 74 neonates and monitored them for survival. In 2015 and 2016, we monitored 50 and 35 calving females for signs of neonatal mortality using changes in adult female velocities and assessed seasonal calf survival by aerial surveys. In 2013 and 2014 (pooled), survival to 9 months was 0.34 (95% CI = 0.23–0.52) for collared calves, and in 2015 and 2016 (pooled) survival was 0.35 (95% CI = 0.26–0.48) for uncollared calves. Mortality in all 4 years was high during the first 50 days of life. In 2013 and 2014 (pooled), calving sites were relatively safe for collared neonates; predator‐kills occurred a median 17.0 days after departure and a median 1,142 m from calving sites. Predation was the leading cause of death of collared calves (84% of mortalities), with wolves (Canis lupus) accounting for 77% of these. Other forms of mortality for collared and uncollared calves included drowning, infection, vehicle collision, and natural abandonment. We documented higher wolf predation than other recent studies with similar predator communities. Identifying specific causes of calf mortality and understanding their relations to various landscape characteristics and other extrinsic factors should yield insight into mechanisms contributing to the declining moose population in northeastern Minnesota and serve as a basis for ecologically sound management responses. © 2019 The Wildlife Society.
Kinetics of oxidation of iron(II) ions with lipid hydroperoxides
Authors: Mihaljević Branka
Published: April 2019

One of the pathways for excessive production of free radicals is the decomposition of lipid hydroperoxides catalyzed by iron. A number of hydroperoxides of unsaturated fatty acids (LOOH), some prepared in our laboratory and others extracted from biological materials, were used to determine the rate constants of Fe2+ oxidation by measuring the formation rate of Fe3+ ions in the presence of simple unidentate ligands, chloride, and thiocyanate as the [FeCl]2+ and [FeNCS]2+ complexes, in a deoxygenated dichloromethane:methanol (2:1, v/v) mixture. The rates of Fe2+ oxidation with prepared LOOHs via the [FeNCS]2+ complex were approximately the same‐the average second‐order reaction rate constant was 1390 ± 340 dm3 mol−1 s−1; the rate constants of LOOHs from different biological materials were in the same range. The rates measured as the [FeNCS]2+ complex were somewhat higher than the rates measured as the [FeCl]2+ complex, indicating that ligands could interact in the transition state, thus affecting the disruption of the intermediate complex. Since there were no significant differences in the activation thermodynamic parameters for reactions within the reaction series of studied hydroperoxides, it was assumed that the oxidation proceeded by an inner sphere mechanism, considering that the breakdown of the successor inner sphere complex with the homolytic cleavage of peroxide bonds of hydroperoxides forming reactive alkoxyl radicals was the rate‐limiting step. Based on this research, an indirect spectrophotometric method for quantitative determination of LOOH was reestimated. The microprocedure proposed for the lipid hydroperoxide assay could be applied to follow the early stages of lipid peroxidation processes in real biological samples.
Kinetics and mechanism of trichloroisocyanuric acid/NaNO2‐triggered nitration of aromatic compounds under acid‐free and Vilsmeier‐Haack conditions
Authors: Bhooshan M. , Rajanna K. C. , Govardhan D. , Venkanna P. , Satish Kumar M.
Published: April 2019

Kinetics and mechanism of nitration of aromatic compounds using trichloroisocyanuric acid (TCCA)/NaNO2, TCCA‐N,N‐dimethyl formamide (TCCA‐DMF)/NaNO2, and TCCA‐N,N‐dimethyl acetamide (TCCA‐DMA)/NaNO2 under acid‐free and Vilsmeier‐Haack conditions. Reactions followed second‐order kinetics with a first‐order dependence on [Phenol] and [Nitrating agent] ([TCCA], [(TCCA‐DMF)], or [(TCCA‐DMA)] >> [NaNO2]). Reaction rates accelerated with the introduction of electron‐donating groups and retarded with electron‐withdrawing groups, but did not fit well into the Hammett's theory of linear free energy relationship or its modified forms like Brown‐Okamoto or Yukawa‐Tsuno equations. Rate data were analyzed by Charton's multiple linear regression analysis. Isokinetic temperature (β) values, obtained from Exner's theory for different protocols, are 403.7 K (TCCA‐NaNO2), 365.8 K (TCCA‐DMF)/NaNO2, and 358 K (TCCA‐DMA)/NaNO2. These values are far above the experimental temperature range (303‐323 K), indicating that the enthalpy factors are probably more important in controlling the reaction.
From presumed benign neck masses to delayed recognition of human papillomavirus–positive oropharyngeal cancer
Authors: Davis Ruth J. , Rettig Eleni , Aygun Nafi , Rooper Lisa , D'Souza Gypsyamber , Eisele David W. , Fakhry Carole
Published: April 2019

Objectives/Hypothesis

To describe patients with delayed diagnosis of human papillomavirus–positive oropharyngeal squamous cell carcinoma (HPV‐OPC) after initial incorrect diagnosis of branchial cleft cyst or nondiagnostic workup of unilateral neck mass.

Study Design

Retrospective case series.

Methods

Patients with delayed diagnosis of HPV‐OPC after initial nondiagnostic workup for unilateral neck mass were eligible. Medical record abstraction was performed to describe clinical characteristics at initial presentation and later diagnosis of HPV‐OPC. To estimate nodal growth rates, the short axis diameter of the lymph nodes was determined from imaging reports.

Results

Six patients met eligibility criteria. After a median interval of 42 months (range, 3 months–7 years) from initial presentation with unilateral neck mass, patients were diagnosed with HPV‐OPC. At the time of HPV‐OPC diagnosis, five were AJCC eighth edition overall stage I, and one was stage II. Primary tumors were T0 or T1 in the majority (83.3%, n = 5). Among five patients with available serial imaging, despite diagnostic delay, three of five still had a single lymph node without involvement of additional nodes, whereas the remaining two developed additional suspicious nodes (ipsilateral and contralateral). Two of five developed evidence of extranodal extension. Median lymph node growth was 9.5% per year (range, −6% to 32%).

Conclusions

Although the natural history of HPV‐OPC is not well understood, this case series suggests that it can be slow growing and mimic benign processes, leading to diagnostic delays. Adults presenting with neck masses should undergo complete diagnostic evaluation.

Level of Evidence

4 Laryngoscope, 130:392–397, 2020
The optimal surgical approach for papillary thyroid carcinoma with pathological n1 metastases: An analysis from the SEER database
Authors: Ji Tingting , Chen Jun , Mou Jianing , Ni Xin , Guo Yongli , Zhang Jie , Wang Shengcai , Wang Wei , Zhang Xin , Tai Jun
Published: April 2019

Objectives/Hypothesis

The definition of large‐volume pathologic N1 metastases has been changed in the 2017 version 2 of the National Comprehensive Cancer Network guidelines, leading to a controversy over the optimal surgical approach selection for patients with biopsy‐proven papillary thyroid carcinoma (PTC). The aim of this study was to investigate the therapeutic efficacy of total thyroidectomy (TT) and thyroid lobectomy (TL) for these patients.

Study Design

Retrospective population‐based database analysis.

Methods

A total of 906 consecutive PTC patients with pathologic N1 metastases (>5 involved nodes with metastases ≤5 mm in the largest dimension) were retrieved from the Surveillance, Epidemiology, and End Results database, and divided into two groups (≤2 mm, >2–5 mm) based on the size of the extent of disease. Overall survival (OS) was then compared between patients treated with TT and TL, followed by Cox proportional hazards regression analysis to explore multiple prognostic factors.

Results

OS favored TT compared with TL in patients with more than five involved nodes and metastases >2 to 5 mm in the largest dimension (P < .05). Cox analysis showed that the TL was not an independent factor associated with poorer OS than TT in these patients (P > .05).

Conclusions

TT showed better survival than TL for patients with more than five involved nodes and metastases >2 to 5 mm in the largest dimension. For patients with more than five involved nodes and metastases ≤2 mm in the largest dimension, either TT or TL can be recommended because there was no difference in survival.

Level of Evidence

NA Laryngoscope, 130:269–273, 2020
The changing landscape of vestibular schwannoma diagnosis and management: A cross‐sectional study
Authors: Goshtasbi Khodayar , Abouzari Mehdi , Moshtaghi Omid , Sahyouni Ronald , Sajjadi Autefeh , Lin Harrison W. , Djalilian Hamid R.
Published: April 2019

Objectives

To assess the current state of the diagnosis and management of vestibular schwannoma (VS) as well as treatment trends, and to evaluate the role of treatment setting and various specialists in treatment plan.

Methods

Patients diagnosed with VS completed a voluntary and anonymous survey. The questionnaires were distributed through Acoustic Neuroma Association website, Facebook page, and e‐mail newsletters from January to March 2017.

Results

In total, 789 VS patients completed the survey. Of those, 414 (52%) underwent surgery; 224 (28%) underwent radiotherapy; and 121 (15%) were observed. General otolaryngologists diagnosed 62% of responders, followed by primary care (11%) and neurotologists (10%). Patients who underwent surgery were significantly younger and had larger tumors compared to those treated with radiation or observation. The ratio of patients having nonsurgical versus surgical resection changed from 1:2 to 1:1 for the periods of 1979 through 2006 versus 2007 through 2017, respectively. Neurosurgeons (40%) and neurotologists (38%) were the most influential in treatment discussion. Neurotologists (P < 0.001) and general otolaryngologists (P = 0.04) were more influential than neurosurgeons for the decision process in patients with smaller tumors. Patients treated at academic versus nonacademic private institutions reported similar tumor sizes (P = 0.27), treatment decisions (P = 0.09), and decision satisfaction (P = 0.78).

Conclusion

There is a continuing trend toward nonsurgical management, with approximately half of the patients opting for nonsurgical management. In this cohort, the patients commonly presented with otologic symptoms and otolaryngologists made the most diagnoses. Neurotologists and neurosurgeons were the most influential in treatment discussion.

Level of Evidence

NA Laryngoscope, 130:482–486, 2020
Long‐term results of sleep‐related quality‐of‐life and behavioral problems after adenotonsillectomy
Authors: Song In Sik , Hong Seung‐No , Joo Jae Woo , Han Mun Soo , Hwang Sun Jin , Seo Min Young , Lee Seung Hoon
Published: April 2019

Objectives

Improvements in sleep‐related quality of life (QOL) and behavioral problems have been observed in children with obstructive sleep apnea (OSA) during a short‐term follow‐up after adenotonsillectomy. Whether this trend continues beyond the short term remains unclear. Therefore, we aimed to evaluate the long‐term effects of surgery in children with OSA.

Methods

The study participants comprised 20 children with OSA who underwent adenotonsillectomy. We used the scores from the Attention Deficit and Hyperactivity Disorder Rating Scale (ADHD‐RS) and total scores from the Korean OSA‐18 Survey (KOSA‐18) before and after adenotonsillectomy to compare and analyze behavioral problems and OSA‐specific health‐related QOL, respectively, during a long‐term follow‐up. Respiratory disturbance parameters from standard polysomnography and subjective symptom scores for snoring and apnea were also investigated.

Results

The mean patient age was 6.6 ± 3.4 years (range, 3–13), and the male‐to‐female ratio was 15:5. The mean follow‐up period was 54.5 months (range, 27–98). The total scores for both ADHD‐RS (from 17.6 to 10.5; P = 0.006) and KOSA‐18 (from 74.3 to 40.7; P = 0.001) decreased significantly from before to after surgery. Significant decreases were also observed in the subjective symptom scores for snoring (from 5.4 to 2.4; P = 0.000) and apnea (from 3.3 to 0.8; P = 0.002).

Conclusion

Significant improvement was observed in sleep‐related QOL and behavioral problems in children with OSA during long‐term follow‐up after adenotonsillectomy.

Level of Evidence

4 Laryngoscope, 130:546–550, 2020
Smoking cessation improves olfactory functions
Authors: Dinc Ayse Secil , Sengezer Tijen , Cayonu Melih , Sahin M. Melih
Published: April 2019

Objectives

The aim of this study was to investigate changes in olfactory function after smoking cessation.

Methods

We conducted a cross‐sectional study involving 28 volunteers who were admitted to the smoking cessation section of our hospital. Olfactory tests were performed immediately before smoking cessation and 45 days after smoking cessation. The duration of smoking and the number of cigarettes smoked per day were noted.

Results

The mean duration of smoking was 25.5 ± 12 years, and the participants smoked 21.6 ± 6.6 cigarettes per day. There was a significant improvement in odor discrimination, odor identification, and TDI scores (i.e., the total score of odor threshold, odor discrimination, and odor identification tests) 45 days after smoking cessation (P = .003, P = .002, and P < .001, respectively). Furthermore, a statistically significant negative correlation was found between the duration of cigarette smoking and the Sniffin’ Sticks olfactory tests performed after smoking cessation, namely odor discrimination, odor identification, and TDI (P = .008, P = .002, P = .001, respectively).

Conclusion

A significant improvement was observed in odor discrimination, odor identification, and TDI scores after smoking cessation. However, this improvement was inversely associated with the duration of smoking, indicating that a longer duration of smoking may result in an insufficient improvement after smoking cessation.

Level of Evidence

4 Laryngoscope, 130:E35–E38, 2020
Hybrid Pericardium with VEGF‐Loaded Hyaluronic Acid Hydrogel Coating to Improve the Biological Properties of Bioprosthetic Heart Valves
Authors: Lei Yang , Deng Lu , Tang Yuyang , Ning Qinggong , Lan Xiaorong , Wang Yunbing
Published: April 2019

Bioprosthetic heart valves (BHVs) used in the clinic are mostly fixed by glutaraldehyde and the lack of endothelialization is a major problem for glutaraldehyde‐fixed pericardia. Hyaluronic acid is a major glycosaminoglycan that exists in native heart valves. Coupled with its inherent biocompatibility, it may enhance endothelial adhesion and proliferation when associated with vascular endothelial growth factor (VEGF). In this study, an optimized system is developed to improve the endothelialization of glutaraldehyde‐fixed pericardium. A hybrid pericardium with VEGF‐loaded hyaluronic acid hydrogel coating is developed by the crosslinking of 1,4‐butanediol diglycidyl ether. The adhesion and growth potential of human umbilical vein endothelial cells (HUVECs) on pericardia, platelet adhesion, and calcification by an in vivo rat subdermal implantation model are investigated. The results show improved HUVEC adhesion and proliferation, less platelet adhesion, and less calcification for hybrid pericardium by introducing the coating of VEGF‐loaded hyaluronic acid hydrogel. Thus, the coating of VEGF‐loaded hyaluronic acid hydrogel on pericardium is a promising approach to obtain bioprosthetic valves for clinical applications with increased endothelialization and antithrombotic and anticalcification properties.
A New Antimicrobial Agent: Poly (3‐hydroxybutyric acid) Oligomer
Authors: Ma Linlin , Zhang Ziheng , Li Jun , Yang Xingxing , Fei Bin , Leung Polly H. M. , Tao Xiaoming
Published: April 2019

In this work, it is first reported that the poly (3‐hydroxybutyric acid) (PHB) oligomer with a few degrees of polymerization possesses effective antibacterial and antifungal properties. Two preparation methods for the PHB oligomer are described, namely, one‐step ring‐opening polymerization of β‐butyrolactone and extraction from the fermented PHB polymer. An appropriate amount of the synthesized PHB oligomer shows no physiological toxicity to the skin and major organs of mice. Topological application of the synthesized PHB oligomer imparts antimicrobial ability to non‐antibacterial fabrics with washing resistance. The synthesized PHB oligomer offers effective sterilization and promotes wound healing in infected nude mice. Most importantly, the PHB oligomer is also reactive to drug‐resistant bacteria. These results suggest that the PHB oligomer is not only a great candidate for antimicrobial modification but also a promising one for biomedical applications. Finally, the antimicrobial mechanisms of the PHB oligomer are revealed, and these include disruption of biofilm and the bacterial wall/membrane, leakage of the intracellular content, inhibition of protein activity, and change in the transmembrane potential.
Syndioselective Polymerization of Vinylnaphthalene
Authors: Li Shihui , Yan Fangbing , Zhang Zhen , Dou Yanli , Zhang Wanxi , Cui Dongmei
Published: April 2019

Coordination polymerizations of 1‐vinylnaphthalene (1VN), 2‐vinylnaphthalene (2VN) and 6‐methoxy‐2‐vinylnaphthalene (MVN) are carried out at room temperature by using the half‐sandwich scandium precursor FluSiMe3Sc(CH2SiMe3)2(THF) (1) and the constrained geometry configuration rare‐earth metal precursors FluCH2PyLn(CH2SiMe3)2(THF)n[Flu = C13H8, Py = C5H4N; Ln = Sc (2a),n= 0; Ln = Lu (2b), Y(2c),n= 1]. Atactic poly(1VN) and perfect syndiotactic poly(2VN) and poly(MVN) are produced by precursors2a‐2cin a controlled way. Treatment of poly(MVN) with boron tribromide at −20 °C provides a syndiotactic poly(6‐hydroxy‐2‐vinylnaphthalene).