bluuebunny/crossref_metadata_2025 huggingface dataset:
A distal enhancer that directs Otx2 expression in the retinal pigment epithelium and neuroretina
Authors: Bhansali Punita , Cvekl Ales , Liu Wei
Published: October 2019

Background

Homeodomain transcription factor Otx2 is essential for embryonic development of multiple head tissues, including retinal pigment epithelium (RPE) and neuroretina. Temporospatial regulation of Otx2 expression is critical for its functions. Molecular dissection of the cis‐acting enhancers will help elucidate how Otx2 expression is regulated.

Results

We comprehensively characterized distal enhancer hs1150 that was previously identified in a high throughput study. We established multiple transgenic mouse lines in which human hs1150, corresponding mouse hs1150, and two highly conserved sub‐fragments in the mouse hs1150 were individually fused to a minimal hsp68 promoter to drive reporter expression. We found that hs1150 enhancer directed reporter expression in the RPE, neuroretina, and brain in a developmentally regulated manner. Human hs1150‐directed reporter expression largely recapitulated Otx2 expression in the RPE, in the early neuroretina, and to a lesser degree in the early brain. Mouse hs1150, although shorter than human hs1150, exhibited similar enhancer activity, indicating functional conservation of hs1150 enhancer across species. Both of the highly conserved subfragments in mouse hs1150 enhancer directed reporter expression in the early neuroretina, indicating that the hs1150 enhancer has two functional components.

Conclusions

Our findings provide insight into the molecular mechanisms underlying the regulation of Otx2 retinal expression.
Psychological features in obesity: A network analysis
Authors: Calugi Simona , Dalle Grave Riccardo
Published: October 2019

Objective

Enhanced understanding of psychosocial factors associated with obesity may improve knowledge of their interplay mechanisms. The aim of this study was to assess the relationship between psychosocial variables in individuals with obesity using a network analysis.

Methods

Patients seeking treatment for obesity were consecutively recruited from a rehabilitative residential treatment program for severe obesity between January 2016 and March 2019. Each patient completed the following questionnaires: Eating Disorder Examination Questionnaire, Symptom Checklist‐90, Obesity Related Well‐Being, and Weight Bias Internalization Scale. In addition, current body mass index (BMI) was measured, and maximum acceptable and dream BMI were assessed.

Results

The sample comprised 996 patients with obesity (age 52.3 [SD = 16.0] years; BMI 41.8 [SD = 7.8] kg/m2; 65.7% women; 52.2% married or living with a partner). Network analysis showed that interpersonal sensitivity and shape–weight concern, but also internalized weight stigma, were the most central and highly interconnected nodes in the network. In contrast, objective binge‐eating episodes and dietary restraint were the most peripheral and least connected nodes. Eating disorder features and psychological distress formed two clearly separate clusters. No difference in network structure was found between men and women.

Conclusions

The pattern of network node connections supports the importance of assessing psychological distress, interpersonal sensitivity, shape–weight concern, and internalized weight stigma in patients seeking treatment for obesity.
Preaching to the choir or composing new verses? Toward a writerly climate literacy in introductory undergraduate biology
Authors: Duffy Meghan A. , Hammond J. W. , Cheng Susan J.
Published: October 2019

Climate change is one of the most pressing issues facing society today, yet a wide range of misconceptions exist in society about whether or why climate change is happening, what its consequences are, and what can be done to address it. Large introductory biology courses present an opportunity to teach a large number of students—some of whom may never take another course focused on climate, ecology, or the environment—about climate change. However, content knowledge alone may not be enough to prepare students to transform their knowledge into action. To begin understanding how content knowledge interacts with student constructions of climate change solutions, we administered and quantitatively analyzed a survey that examined student views of climate change and how they shifted with instruction during an undergraduate introductory biology course at a large Midwestern university. Almost all participants entered the course agreeing that climate change is occurring, and their certainty about the science of climate change increased after instruction. After taking the course, more participants described climate change as having more immediate impacts, reporting that climate change is already harming people and that climate change will harm them personally. However, both at the beginning and end of the course, participants tended to think that humans would either be unable or unwilling to reduce climate change. They were also more worried about climate change at the end of the course than they were before. Increased concern might result from students becoming more certain of the science and severity of climate change, while remaining pessimistic that humans will effectively act on climate change. This pattern suggests instructors have opportunities to modify curricula in ways that leave students with a greater sense of empowerment and efficacy; we suggest questions that instructors can ask themselves in order to modify their courses with this goal in mind.
Genetic admixture despite ecological segregation in a North African sparrow hybrid zone (Aves, Passeriformes, Passer domesticus × Passer hispaniolensis)
Authors: Päckert Martin , Ait Belkacem Abdelkrim , Wolfgramm Hannes , Gast Oliver , Canal David , Giacalone Gabriele , Lo Valvo Mario , Vamberger Melita , Wink Michael , Martens Jochen , Stuckas Heiko
Published: October 2019

Under different environmental conditions, hybridization between the same species might result in different patterns of genetic admixture. Particularly, species pairs with large distribution ranges and long evolutionary history may have experienced several independent hybridization events over time in different zones of overlap. In birds, the diverse hybrid populations of the house sparrow (Passer domesticus) and the Spanish sparrow (Passer hispaniolensis) provide a striking example. Throughout their range of sympatry, these two species do not regularly interbreed; however, a stabilized hybrid form (Passer italiae) exists on the Italian Peninsula and on several Mediterranean islands. The spatial distribution pattern on the Eurasian continent strongly contrasts the situation in North Africa, where house sparrows and Spanish sparrows occur in close vicinity of phenotypically intermediate populations across a broad mosaic hybrid zone. In this study, we investigate patterns of divergence and admixture among the two parental species, stabilized and nonstabilized hybrid populations in Italy and Algeria based on a mitochondrial marker, a sex chromosomal marker, and 12 microsatellite loci. In Algeria, despite strong spatial and temporal separation of urban early‐breeding house sparrows and hybrids and rural late‐breeding Spanish sparrows, we found strong genetic admixture of mitochondrial and nuclear markers across all study populations and phenotypes. That pattern of admixture in the North African hybrid zone is strikingly different from i) the Iberian area of sympatry where we observed only weak asymmetrical introgression of Spanish sparrow nuclear alleles into local house sparrow populations and ii) the very homogenous Italian sparrow population where the mitogenome of one parent (P. domesticus) and the Z‐chromosomal marker of the other parent (P. hispaniolensis) are fixed. The North African sparrow hybrids provide a further example of enhanced hybridization along with recent urbanization and anthropogenic land‐use changes in a mosaic landscape.
Prolonged plasma glucose elevation on oral glucose tolerance test in young healthy Japanese individuals
Authors: Ishigaki Hirotaka , Yoshida Akihiro , Araki Osamu , Kimura Takao , Tsunekawa Katsuhiko , Shoho Yoshifumi , Nara Makoto , Aoki Tomoyuki , Ogiwara Takayuki , Murakami Masami
Published: October 2019

Aims

This study aims to assess insulin secretion and resistance through oral glucose tolerance test (OGTT) among young Japanese individuals.

Subjects and methods

We enrolled 595 young healthy Japanese individuals aged 22‐29 years. They underwent an OGTT, and their results were divided into 4 groups (I‐IV), according to the time at which their plasma glucose concentration declined below the fasting glucose concentration (30, 60 or 120 minutes or never as groups I, II, III and IV, respectively).

Results

We classified 575 normal glucose‐tolerant subjects into 4 groups (I‐IV) with I: 28 (4.9%), II: 120 (20.9%), III: 143 (24.9%) and IV: 284 (49.4%) individuals. The Matsuda, insulinogenic and disposition indices were decreased from groups I to IV. ROC curves of disposition index reflecting the composition of insulin secretion and sensitivity classified the prolonged glucose elevation group (group III + IV) from the rapid glucose lowering group (group II; AUC = 0.847).

Conclusions

Even in a young and healthy Japanese individual within the physiological range of glycaemic control, there is a sequential decrease in insulin sensitivity and secretion.
Fault‐level coverage analysis of multistate cloud‐RAID storage systems
Authors: Mandava Lavanya , Xing Liudong , Wang Chaonan
Published: October 2019

In this paper, a multistate cloud‐RAID (redundant array of independent disks) storage system subject to fault‐level coverage (FLC) is modeled and analyzed. Most of the existing works on reliability analysis of cloud‐RAID systems have either assumed binary‐state for storage disks or failed to consider imperfect fault coverage, an inherent behavior of fault‐tolerant systems. This work advances the state of the art by proposing a combinatorial method based on multivalued decision diagrams for analyzing reliability of a multistate cloud‐RAID system with FLC. The FLC is one common type of imperfect fault coverage behaviors, where the system fault recovery capability is dependent on the number of disk faults happening within a certain recovery window. Effects of the functional dependence behavior between the RAID controller and disks are addressed. The method is illustrated through a detailed analysis of an example cloud‐RAID 5 storage system. Numerical results are provided to show the impact of different design parameters on system performance. These results also demonstrate that failure to consider FLC leads to inaccurate system state probabilities, further misleading system design activities based on these probabilities such as maintenance and optimization.
Energy absorption from parks of point‐absorbing wave energy converters in the Swedish exclusive economic zone
Authors: Engström Jens , Göteman Malin , Eriksson Mikael , Bergkvist Mikael , Nilsson Erik , Rutgersson Anna , Strömstedt Erland
Published: October 2019

In a future energy system based on renewable energy sources, wave energy will most likely play a role due to its high energy potential and low intermittency. The power production from parks of wave energy converters of point absorber type has been extensively studied. This is also the case for the wave energy resource at many coastal areas around the globe. Wave energy has not yet reached a commercial level, and a large variety of technologies exist; therefore, an established method to calculate the technical potential for wave energy has still not been established. To estimate the technical potential of wave energy conversion, some approximations inevitably need to be taken due to the systems high complexity. In this study, a detailed mapping of the wave climate and simulation of large arrays of hydrodynamically cross‐coupled wave energy converters are combined to calculate the technical potential for wave energy conversion in the Swedish exclusive economic zone. A 16‐year wave data set distributed in a 1.1 km × 1.1 km grid is used to calculate the absorbed energy from a park of 200 generic point absorbers. The areas with best potential have an average annual energy absorption of 16 GWh for the selected wave energy park adapted to 1 km2 when using a constant damping, while the theoretical upper bound is 63 GWh for the same area.
Assessment of shoulder function following scapular free flap
Authors: Patel Krupal B. , Low Tsu‐Hui (Hubert) , Partridge Allison , Nichols Anthony C. , MacNeil S. Danielle , Yoo John , Fung Kevin
Published: October 2019

Background

The scapular system free flap has been increasing in popularity to reconstruct short segment mandibular bony defects. It is important to assess donor site morbidities systematically.

Methods

Prospective cohort study using objective measures of range of motion (ROM) and shoulder strength were measured. Subjective disability was evaluated with validated questionnaires—Neck Disability Impairment Index and Shoulder Pain and Disability Index.

Results

Twenty‐six patients were recruited—19 with scapular tip and 7 with lateral border scapular free flap. Decreased ROM on the operated side was noted for shoulder abduction, shoulder flexion, and external rotation. No significant difference was noted for shoulder extension. Strength was reduced for shoulder flexion, shoulder abduction, and external rotation. Subjective measurements did not indicate significant shoulder function disruption.

Conclusion

Patients with scapular free flap reconstruction did not experience significant shoulder morbidity. Measures of shoulder ROM and power were objectively affected; however, subjective measures of shoulder disability were not significantly affected.
Quantitative guidance for efficient vertical flow measurements at the sediment–water interface using temperature–depth profiles
Authors: Irvine Dylan J. , Kurylyk Barret L. , Briggs Martin A.
Published: October 2019

Upward discharge to surface water bodies can be quantified using analytical models based on temperature–depth (T‐z) profiles. The use of sediment T‐z profiles is attractive as discharge estimates can be obtained using point‐in‐time data that are collected inexpensively and rapidly. Previous studies have identified that T‐z methods can only be applied at times of the year when there is significant difference between the streambed–water interface and deeper sediment temperatures (e.g., winter and summer). However, surface water temperatures also vary diurnally, and the influence of these variations on discharge estimates from T‐z methods is poorly understood. For this study, synthetic T‐z profiles were generated numerically using measured streambed interface temperature data to assess the influence of diurnal temperature variations on discharge estimation and provide insight into the suitable application of T‐z methods. Results show that the time of day of data collection can have a substantial influence on vertical flux estimates using T‐z methods. For low groundwater discharge fluxes (e.g., 0.1 m d−1), daily transience in streambed temperatures led to relatively large errors in estimated flow magnitude and direction. For higher discharge fluxes (1.5 m d−1), the influence of transient streambed temperatures on discharge estimates was strongly reduced. Discharge estimates from point‐in‐time T‐z profiles were most accurate when the uppermost point in the T‐z profile was near the bed interface daily mean (two time periods daily). Where temperature time series data are available, daily averaged T‐z profiles can produce accurate discharge estimates across a wide range of discharge rates. Seasonality in shallow groundwater temperature generally had a negligible influence on vertical flow estimates. These findings can be used to plan field campaigns and provide guidance on the optimal application of T‐z methods to quantify vertical groundwater discharge to surface water bodies.
Spatio‐temporal patterns of the interaction between groundwater and surface water in plains
Authors: Guevara Ochoa Cristian , Medina Sierra Agustín , Vives Luis , Zimmermann Erik , Bailey Ryan
Published: October 2019

The study of the dynamics of anthropic disturbances that have an effect on the hydrological systems in plains requires integral simulation tools for their diagnosis. The objective of this article is, first, to analyse and reproduce the spatio‐temporal interactions between groundwater (GW) and surface water, net recharge, GW level, surface run‐off, and evapotranspiration in the upper creek basin of Del Azul, which is located in the centre of the province of Buenos Aires, Argentina, and second, to obtain insights to apply the methodology to other similar situations. For this purpose, a model coupling the semidistributed hydrological model (Soil and Water Assessment Tool [SWAT]) and the hydrogeological model (MODFLOW) has been used. A simulation was carried out for a period of 13 years (2003–2015) on a daily scale. The application of the SWAT–MODFLOW coupling gave good results based on the adjustment between the calculated flows and levels, reaching a Nash–Sutcliffe of 0.6 and R20.6 at the Seminario hydrometric station located at the watershed outlet point. According to the annual average balance, out of the total rainfall, evapotranspiration accounts for 85%, recharge accounts for 10.2%, and surface run‐off accounts for 4.8%. Annual and monthly trends of the stream–aquifer interaction were determined, obtaining on average an annual GW discharge of 34 mm and an annual average recharge of the stream to the aquifer of 1.4 mm. Monthly GW discharges are higher in winter–spring (July to December with an average of 3.3 mm) and lower in summer–autumn (January to June with an average of 2.8 mm). The monthly average recharge of the stream towards the aquifer varies from 0.02 to 0.36 mm and is higher in March, May, and August, when water excess is produced in the basin. Through the analysis of coupled modelling, it is possible to analyse and reproduce the spatio‐temporal transitions of flow existing between the stream, the hyporheic zone, and the aquifer.
Estimating obstetric and gynecologic surgical rate: A benchmark of surgical capacity building in Ghana
Authors: Gyedu Adam , Lester Lynette , Stewart Barclay , Danso Kwabena A. , Salia Emmanuella L. , Quansah Robert , Donkor Peter , Mock Charles
Published: October 2019

Objective

To estimate the annual rate of obstetric and gynecologic (ObGyn) operations performed in Ghana and establish a baseline for tracking the expansion of Ghana's surgical capacity.

Methods

Data were obtained for ObGyn operations performed in Ghana between 2014 and 2015 from a nationally representative sample of hospitals and scaled up for national estimates. Operations were classified as “essential” or “other” according to The World Bank's Disease Control Priorities Project. Data were used to calculate cesarean‐to‐total‐operation ratio (CTR) and estimate the rate of cesarean deliveries based on the number of live births in 2014.

Results

A total of 90 044 (95% uncertainty interval [UI] 69 461–110 628) ObGyn operations were performed nationally over the 1‐year period, yielding an annual national ObGyn operation rate of 881/100 000 females aged 12 years and over (95% UI 679–1082). Eighty‐seven percent were essential procedures, 80% of which were cesarean deliveries. District hospitals performed 71% of ObGyn operations. The national rate of cesarean deliveries was 7.2% and the CTR was 0.27.

Conclusion

The cesarean delivery rate of 7.2% suggests inadequate access to obstetric care. The CTR of 0.27 suggests inadequate overall surgical capacity. These measures, along with estimates of distribution of procedures by hospital level, provide useful baseline data to support surgical capacity building efforts in Ghana and similar countries.
Evaluation of effectiveness of 45S5 bioglass doped with niobium for repairing critical‐sized bone defect in in vitro and in vivo models
Authors: de Souza Lucas P. L. , Lopes João H. , Ferreira Filipe V. , Martin Richard A. , Bertran Celso A. , Camilli José A.
Published: October 2019

Here, we investigated the biocompatibility of a bioactive sodium calcium silicate glass containing 2.6 mol% Nb2O5 (denoted BGPN2.6) and compare the results with the archetypal 45S5 bioglass. The glass bioactivity was tested using a range of in vitro and in vivo experiments to assess its suitability for bone regeneration applications. in vitro studies consisted of assessing the cytocompatibility of the BGPN2.6 glass with bone‐marrow‐derived mesenchymal stem cells (BM‐MSCs). Systemic biocompatibility was verified by means of the quantification of biochemical markers and histopathology of liver, kidneys, and muscles. The glass genotoxicity was assessed using the micronucleus test. The regeneration of a calvarial defect was assessed using both qualitative and quantitative analysis of three‐dimensional microcomputed tomography images. The BGPN2.6 glass was not cytotoxic to BM‐MSCs. It is systemically biocompatible causing no signs of damage to high metabolic and excretory organs such as the liver and kidneys. No mutagenic potential was observed in the micronucleus test. MicroCT images showed that BGPN2.6 was able to nearly fully regenerate a critical‐sized calvarial defect and was far superior to standard 45S5 Bioglass. Defects filled with BGPN2.6 glass showed over 90% coverage compare to just 66% for 45S5 Bioglass. For one animal the defect was completely filled in 8 weeks. These results clearly show that Nb‐containing bioactive glasses are a safe and effective biomaterial for bone replacement.
Recent Trends in the Synthesis of Benzimidazoles From o‐Phenylenediamine via Nanoparticles and Green Strategies Using Transition Metal Catalysts
Authors: Singhal Sugandha , Khanna Pankaj , Panda Siva S. , Khanna Leena
Published: October 2019

Benzimidazole is a heterocyclic moiety of immense importance as it acts as a primary “biolinker” in diverse synthetic routes to obtain bioactive compounds. Substituted benzimidazoles are known to possess a varied range of pharmacological applications, namely, anti‐cancer, anti‐diabetic, anti‐inflammatory, and antiviral like anti‐HIV and anti‐fungal. A number of reviews covering the important aspects of benzimidazoles such as pharmacological activities, SAR studies, and well‐known methods of synthesis have appeared in the literature. However, green synthetic methods particularly using transition metal (TM) catalysts and their nanoparticles, although being more viable and extensively applied by researchers in the present scenario, have not been exclusively and expansively reviewed. Besides this, the vital precursors required for knitting the skeleton of benzimidazole are mainly o‐aryldiamines. The conventional synthesis generally involved the condensation of these diamines with carbonyl/carboxylic acid derivatives either via high temperature heating or via adding strong acids, mostly resulting in poor yields or mixtures. However, recent trends are replacing these conditions by mild and green conditions through TM catalysts. Therefore, the current review emphasizes on the recent trends adopted in the synthesis of benzimidazoles using condensation reaction of o‐phenylenediamines and various aldehydes/ester/amide/alcohols with TM in a catalytic role in nanoform and under environmentally benign green conditions.
Mass wasting processes affecting the surface of an alpine talus slope: Annual sediment budgets 2009–2018 at Flüelapass, eastern Swiss Alps.
Authors: Kenner Robert
Published: October 2019

An alpine permafrost talus slope at Flüelapass (Eastern Swiss Alps) was observed using annual terrestrial laser scanning measurements between 2009 and 2018. The high‐resolution digital elevation models derived from these measurements enabled the detection and quantification of mass wasting processes with an accuracy of a few centimeters. Rock fall, snow avalanche erosion, and debris flow tracks could be distinguished and their quantitative and qualitative contribution to talus slope growth and shaping was examined. Erosion rates were calculated for each of the investigated processes and an estimate for the recession rate of the talus slope head wall is reported. Currently, debris flows supply most of the debris inputs to the talus slope, while snow avalanches were found to play an important role in reshaping its surface morphology. Rock fall causes distinct grain size sorting down the slope, as the travel distance of rocks increase with their size. The presented data and results illustrate the current processes occurring at the talus slope surface, which appear to differ in quantity and quality from those during the onset of the talus slope formation.
Microwave‐Assisted, Base‐Catalyzed Synthesis of Fatty Acid Methyl Esters from Seeds and Fish Oil Supplements
Authors: Malko Rada , Larraza Isabel
Published: October 2019

Growing health awareness has resulted in the increased use of dietary supplements derived from plants and marine sources, leaving consumers unsure of their best options. There were three objectives of the present study. The first was to design and evaluate an efficient derivatization procedure. The second was to perform a comparative analysis of liquid oils and their corresponding capsules of hemp, chia, and flax seeds. The final objective was to determine the fatty acid (FA) composition of six fish oil products and compare it to the one provided on the label. For the FA profiling, we implemented two efficient, one‐step, sustainable methods with high percentage recovery for the synthesis of FA methyl esters (FAME), which use base catalysis and microwave‐assisted heating. Our results found no difference in nutritional value between liquid oils and capsules of the seed supplements, with flaxseed and chia offering a higher, beneficial n‐3:n‐6 ratio compared to hemp oil. Four of the fish oils analyzed contained significantly less eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) than their reported label, and the other two not only agreed with the manufacturers' declaration but were able to fulfill the daily adequate intake (AI) with fewer capsules.
A Multi‐Foci Metalens with Polarization‐Rotated Focal Points
Authors: Zang Xiaofei , Ding Hongzhen , Intaravanne Yuttana , Chen Lin , Peng Yan , Xie Jingya , Ke Qinghong , Balakin Alexey V. , Shkurinov Alexander P. , Chen Xianzhong , Zhu Yiming , Zhuang Songlin
Published: October 2019

Benefiting from the unprecedented capability of metasurfaces in the manipulation of light propagation, metalenses can provide novel functions that are very challenging or impossible to achieve with conventional lenses. Here, an approach to realizing multi‐foci metalenses is proposed and experimentally demonstrated with polarization‐rotated focal points based on geometric metasurfaces. Multi‐foci metalenses with various polarization rotation directions are developed using silicon pillars with spatially variant orientations. The focusing characteristic and longitudinal polarization‐dependent imaging capability are demonstrated upon the illumination of a linearly polarized light beam. The uniqueness of this multi‐foci metalens with polarization‐rotated focal points may open a new avenue for imaging, sensing, and information processing.
The bright side and dark side of trust: The mediating effect of franchisor trust on performance
Authors: Minarikova Dana , Mumdziev Nada , Griessmair Michele , Windsperger Josef
Published: October 2019

Previous literature has not examined the dual role of trust in franchise relationships. We extend the franchise and relational governance literature by showing that trust has both a “bright side” and a “dark side” in franchisor–franchisee relationships. Based on transaction cost and knowledge‐based reasoning, we argue that intangible knowledge assets and environmental uncertainty have an indirect effect on performance via trust, due to its relational risk and knowledge exchange effect. Using data from the franchise sector in Germany, we show that trust positively mediates the impact of intangible knowledge assets and negatively mediates the impact of environmental uncertainty on franchisor performance. The first effect refers to the “bright side” of trust showing that intangible brand name assets increase trust which, in turn, has a positive effect on performance. Conversely, the second effect refers to the “dark side” of trust highlighting that environmental uncertainty diminishes trust resulting in a negative effect on performance.
Dynamics of breather waves and rogue waves on a soliton background in the coupled Hirota systems
Authors: Liu Wenhao , Zhang Yufeng , Shi Dandan
Published: October 2019

Based on the Darboux‐dressing transformation, the new localized wave solutions of the coupled Hirota systems are constructed with a detailed derivation. Furthermore, by using Taylor series expansions for the trigonometric and exponential functions of our obtained exact breather solution, the N‐order rogue wave solutions are also expressed explicitly. Besides, the dynamics of these rogue wave solutions are illustrated with some vivid graphics.
Ratio of Conjugated Chenodeoxycholic to Muricholic Acids is Associated with Severity of Nonalcoholic Steatohepatitis
Authors: Chen Jin , Zheng Minghua , Liu Jun , Luo Yan , Yang Wenjun , Yang Jing , Liu Juan , Zhou Jingxing , Xu Chengfu , Zhao Faling , Su Mingming , Zang Shufei , Shi Junping ,   on behalf of the Chinese NAFLD Clinical Research Network (CNAFLD CRN)
Published: October 2019

Objective

Bile acids (BAs) are important molecules in the progression of nonalcoholic fatty liver disease. This study aimed to investigate BA profile alterations in Chinese nonalcoholic steatohepatitis (NASH) patients.

Methods

BA profiles in serum and liver tissues were determined by ultraperformance liquid chromatography coupled to tandem mass spectrometry in patients from two different clinical centers.

Results

A total of 134 participants were enrolled in this study to serve as the training (n = 87) and validation (n = 47) cohorts. The ratio of circulating conjugated chenodeoxycholic acids to muricholic acids (P = 0.001) was elevated from healthy controls to non‐NASH individuals to NASH individuals in a stepwise manner in the training cohort and was positively associated with the histological severity of NASH: steatosis (R2 = 0.12), lobular inflammation (R2 = 0.12), ballooning (R2 = 0.11), and fibrosis stage (R2 = 0.18). The ratio was elevated in the validation cohort of NASH patients (P < 0.001), and it was able to predict NASH (area under the receiver operating characteristic curve: 75%) and significant fibrosis (area under the receiver operating characteristic curve: 71%) in these two cohorts. Moreover, this elevated ratio and impaired farnesoid X receptor signaling were found in the NASH liver.

Conclusions

Altered BA profile in NASH is closely associated with the severity of liver lesions, and it has the potential for predicting NASH development.
Introducing rigid pyrimidine ring to improve the mechanical properties and thermal‐oxidative stabilities of phthalonitrile resin
Authors: Yang Kaixiong , Chen Xinggang , Zhang Zhenjiang , Yu Xiaoyan , Naito Kimiyoshi , Zhang Qingxin
Published: October 2019

In this study, a novel phthalonitrile monomer containing pyrimidine ring, 4,6‐bis[3‐(3,4‐dicya‐ nophenoxy)phenoxy]pyrimidine (BCPM), was successfully synthesized by nucleophilic substitution reaction with resorcinol, 4,6‐dichloropyrimidine and 4‐nitrophthalonitrile. The BCPM monomer was cured by different temperature programs with 4‐(aminophenoxy)phthalonitrile (APPH) as catalyst to give the polymers. The molecular structures of the BCPM monomer and the polymers were investigated by Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. Differential scanning calorimetric (DSC) analysis was performed to study the processability of the BCPM monomer, which showed a wide processing window of about 117°C. The mechanical properties and thermal‐oxidative stability of the polymer were characterized by dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA), respectively, which indicated that the polymers exhibited excellent storage modulus, high glass transition temperature over 400°C, and outstanding thermal stability. The polymers also have low water absorption capacity and are suitable for humid environments.
GeTFEP: A general transfer free energy profile of transmembrane proteins
Authors: Tian Wei , Naveed Hammad , Lin Meishan , Liang Jie
Published: October 2019

Free energy of transferring amino acid side‐chains from aqueous environment into lipid bilayers, known as transfer free energy (TFE), provides important information on the thermodynamic stability of membrane proteins. In this study, we derived a TFE profile named General Transfer Free Energy Profile (GeTFEP) based on computation of the TFEs of 58 β‐barrel membrane proteins (βMPs). The GeTFEP agrees well with experimentally measured and computationally derived TFEs. Analysis based on the GeTFEP shows that residues in different regions of the transmembrane (TM) segments of βMPs have different roles during the membrane insertion process. Results further reveal the importance of the sequence pattern of TM strands in stabilizing βMPs in the membrane environment. In addition, we show that GeTFEP can be used to predict the positioning and the orientation of βMPs in the membrane. We also show that GeTFEP can be used to identify structurally or functionally important amino acid residue sites of βMPs. Furthermore, the TM segments of α‐helical membrane proteins can be accurately predicted with GeTFEP, suggesting that the GeTFEP is of general applicability in studying membrane protein.
Vegetable butters and oils in skin wound healing: Scientific evidence for new opportunities in dermatology
Authors: Poljšak Nina , Kreft Samo , Kočevar Glavač Nina
Published: October 2019

The use of vegetable butters and oils shows promising results in the treatment of skin wounds, as they have an effective impact on the phases of the wound‐healing process through their antimicrobial, anti‐inflammatory, and antioxidative activities and by promoting cell proliferation, increasing collagen synthesis, stimulating dermal reconstruction, and repairing the skin's lipid barrier function.

In this article, in vitro and in vivo studies of argan (Argania spinosa), avocado (Persea americana), black cumin (Nigella sativa), calophyllum (Calophyllum inophyllum), coconut (Cocos nucifera), cranberry (Vaccinium macrocarpon), grape (Vitis vinifera), green coffee (Coffea arabica), lentisk (Pistacia lentiscus), linseed (Linum usitatissimum), lucuma (Pouteria lucuma), mango (Mangifera indica), olive (Olea europaea), pomegranate (Punica granatum), pumpkin (Cucurbita pepo), rapeseed (Brassica napus), sea buckthorn (Hippophae rhamnoides), and sunflower (Helianthus annuus) oils were reviewed. In many cases, vegetable oils proved to be more effective than synthetic wound‐healing compounds used as controls.

The fatty‐acid components of vegetable oils are assumed to play a major role in the wound‐healing process, in particular polyunsaturated fatty acids such as linoleic acid. Evidence shows that oils with a higher linoleic to oleic acid ratio are more effective for lipid barrier repair. However, in depth studies are needed to gain knowledge about vegetable oils' effects on the skin and vice versa.
Development of a relative quantification method for infrared matrix‐assisted laser desorption electrospray ionization mass spectrometry imaging of Arabidopsis seedlings
Authors: Bagley M. Caleb , Stepanova Anna N. , Ekelöf Måns , Alonso Jose M. , Muddiman David C.
Published: October 2019

Rationale

Mass spectrometry imaging of young seedlings is an invaluable tool in understanding how mutations affect metabolite accumulation in plant development. However, due to numerous biological considerations, established methods for the relative quantification of analytes using infrared matrix‐assisted laser desorption electrospray ionization (IR‐MALDESI) mass spectrometry imaging are not viable options. In this study, we report a method for the quantification of auxin‐related compounds using stable‐isotope‐labelled (SIL) indole‐3‐acetic acid (IAA) doped into agarose substrate.

Methods

Wild‐type Arabidopsis thaliana seedlings, sur2 and wei8 tar2 loss‐of‐function mutants, and YUC1 gain‐of‐function line were grown for 3 days in the dark in standard growth medium. SIL‐IAA was doped into a 1% low‐melting‐point agarose gel and seedlings were gently laid on top for IR‐MALDESI imaging with Orbitrap mass spectrometry analysis. Relative quantification was performed post‐acquisition by normalization of auxin‐related compounds to SIL‐IAA in the agarose. Amounts of auxin‐related compounds were compared between genotypes to distinguish the effects of the mutations on the accumulation of indolic metabolites of interest.

Results

IAA added to agarose was found to remain stable, with repeatability and abundance features of IAA comparable with those of other compounds used in other methods for relative quantification in IR‐MALDESI analyses. Indole‐3‐acetaldoxime was increased in sur2 mutants compared with wild‐type and other mutants. Other auxin‐related metabolites were either below the limits of quantification or successfully quantified but showing little difference among mutants.

Conclusions

Agarose was shown to be an appropriate sampling surface for IR‐MALDESI mass spectrometry imaging of Arabidopsis seedlings. SIL‐IAA doping of agarose was demonstrated as a viable technique for relative quantification of metabolites in live seedlings or tissues with similar biological considerations.
Ion mobility spectrometry – Mass spectrometry coupling for synthetic polymers
Authors: Charles Laurence , Chendo Christophe , Poyer Salomé
Published: October 2019

This review covers applications of ion mobility spectrometry (IMS) hyphenated to mass spectrometry (MS) in the field of synthetic polymers. MS has become an essential technique in polymer science, but increasingly complex samples produced to provide desirable macroscopic properties of high‐performance materials often require separation of species prior to their mass analysis. Similar to liquid chromatography, the IMS dimension introduces shape selectivity but enables separation at a much faster rate (milliseconds vs minutes). As a post‐ionization technique, IMS can be hyphenated to MS to perform a double separation dimension of gas‐phase ions, first as a function on their mobility (determined by their charge state and collision cross section, CCS), then as a function of their m/z ratio. Implemented with a variety of ionization techniques, such coupling permits the spectral complexity to be reduced, to enhance the dynamic range of detection, or to achieve separation of isobaric ions prior to their activation in MS/MS experiments. Coupling IMS to MS also provides valuable information regarding the 3D structure of polymer ions in the gas phase and regarding how to address the question of how charges are distributed within the structure. Moreover, the ability of IMS to separate multiply charged species generated by electrospray ionization yields typical IMS‐MS 2D maps that permit the conformational dynamics of synthetic polymer chains to be described as a function of their length.
Practical optimization of liquid chromatography/mass spectrometry conditions and pretreatment methods toward the sensitive quantification of auxin in plants
Authors: Sugahara Kohtaro , Kitao Kazunori , Yamagaki Tohru , Koyama Tomotsugu
Published: October 2019

Rationale

The plant hormone auxin, indole‐3‐acetic acid, regulates many aspects of plant growth and development. Auxin quantification should offer broad insights into its mechanistic action in plants. However, limited auxin content in plant tissues hampers the establishment of quantification methods without the highest graded instruments or deeply specialized experimental techniques.

Methods

In this study, we detailed optimized conditions for high‐performance liquid chromatography coupled with triple‐quadrupole mass spectrometry (LC/MS). We compared LC/MS conditions, such as columns, mobile phases, parameters of acquisition methods (selective or multiple ion monitoring), dwell times (DTs), and channel numbers, using differentially mixed authentic auxin and its related compounds. We further investigated pretreatment methods through the optimization of auxin recovery and irrelative compound removal from plant tissues prior to the LC/MS analysis.

Results

Our LC/MS analysis demonstrated the particular importance of the column, DTs, and channel numbers on detection sensitivity. Our comparative analysis developed optimal pretreatment methods, including the pulverization of plants, concentration of extract through centrifugal evaporation, and removal of irrelative metabolites using liquid–liquid extraction and a spin filter. We injected plant samples into our LC/MS system, quantified auxin and eight related compounds in a single measurement, and determined the auxin increase in an auxin over‐producing mutant.

Conclusions

Our practical optimization of LC/MS conditions and pretreatment methods provides detailed experimental processes toward the sensitive quantification of auxin from 10 mg of plant tissue. These processes have not always been clearly documented; therefore, our protocol could broadly contribute to technical advances in plant growth and development research.
Methanogenic pathways and δ13C values from swine manure with a cavity ring‐down spectrometer: Ammonia cross‐interference and carbon isotope labeling
Authors: Dalby Frederik R. , Fuchs Andrea , Feilberg Anders
Published: October 2019

Rationale

Carbon isotope ratio analysis using cavity ring‐down spectroscopy (CRDS) offers insight into methanogenic activity. In livestock buildings, measuring 13CH4/12CH4 by CRDS is challenging and prone to errors, due to cross‐interference from NH3. Therefore, an interference‐corrected and improved approach to monitor methanogenic pathways with CRDS was developed and described in this study.

Methods

Cross‐interference from NH3 and other livestock gases on 13CH4/12CH4 was measured using CRDS. The removal efficiency of livestock gases was quantified using proton transfer reaction mass spectrometry. The linearity of the cavity ring‐down spectrometer was tested by dilution of a 13CH4 standard up to 15.6 atom % in CH4. 13C isotope‐labeled acetate was utilized to elucidate the methanogenic pathway contribution in swine manure using a stoichiometric model.

Results

Significant NH3 cross‐interference on 13CH4/12CH4 was observed, and correction factors were calculated. Cross‐interfering gases were effectively removed using a copper scrubber and a Nafion tube. The instrument responded linearly with 13/12C ratios up to 7.6 atom % in CH4. Isotope‐labeled experiments suggested that hydrogenotrophic methanogenesis was dominant and acetate‐derived CH4 was limited in the studied swine manure. The observations were cross‐validated and consistent with measurements of the natural isotope signatures.

Conclusion

NH3 cross‐interference leads to major errors in isotope ratios and therefore in evaluating the relative methanogenic pathway activity. We present methodological approaches, which are crucial to apply in livestock‐related uses where NH3 is abundant. This methodology provides a considerable benefit to advance the understanding and reduction of methane emissions in the livestock sector.
Global decentralized sampled‐data output feedback stabilization for a class of large‐scale nonlinear systems with sensor and actuator failures
Authors: He Wenmin , Li Shi , Xiang Zhengrong
Published: October 2019

In this paper, we investigate global decentralized sampled‐data output feedback stabilization problem for a class of large‐scale nonlinear systems with time‐varying sensor and actuator failures. The considered systems include unknown time‐varying control coefficients and inherently nonlinear terms. Firstly, coordinate transformations are introduced with suitable scaling gains. Next, a reduced‐order observer is designed to estimate unmeasured states. Then, a decentralized sampled‐data fault‐tolerant control scheme is developed with an allowable sampling period. By constructing an appropriate Lyapunov function, it can be shown that all states of the resulting closed‐loop system are globally uniformly ultimately bounded. Finally, the validity of the proposed control approach is verified by using two examples.
An iterative approach for the discrete‐time dynamic control of Markov jump linear systems with partial information
Authors: Oliveira André Marcorin , Costa O. L. V.
Published: October 2019

The
,
and mixed
dynamic output feedback control of Markov jump linear systems in a partial observation context is studied through an iterative approach. By partial information, we mean that neither the state variable x(k) nor the Markov chain θ(k) are available to the controller. Instead, we assume that the controller relies only on an output y(k) and a measured variable
coming from a detector that provides the only information of the Markov chain θ(k). To solve the problem, we resort to an iterative method that starts with a state‐feedback controller and solves at each iteration a linear matrix inequality optimization problem. It is shown that this iterative algorithm yields to a nonincreasing sequence of upper bound costs so that it converges to a minimum value. The effectiveness of the iterative procedure is illustrated by means of two examples in which the conservatism between the upper bounds and actual costs is significantly reduced.
Interfacial Charge Transport in 1D TiO2 Based Photoelectrodes for Photoelectrochemical Water Splitting
Authors: Yu Zhongrui , Liu Haobo , Zhu Mingyuan , Li Ying , Li Wenxian
Published: October 2019

1D nanostructured photoelectrodes are promising for application as photoelectrochemical (PEC) devices for solar energy conversion into hydrogen (H2) owing to the optical, structural, and electronic advantages. Titanium dioxide (TiO2) is the most investigated candidate as a photoelectrode due to its good photostability, low production cost, and eco‐friendliness. The obstacle for TiO2's practical application is the inherent wide bandgap (UV‐lights response), poor conductivity, and limited hole diffusion length. Here, a comprehensive review of the current research efforts toward the development of 1D TiO2 based photoelectrodes for heterogeneous PEC water splitting is provided along with a discussion of nanoarchitectures and energy band engineering influences on interfacial charge transfer and separation of 1D TiO2 composited with different dimensional photoactive materials. The key focus of this review is to understand the charge transfer processes at interfaces and the relationship between photogenerated charge separation and photoelectrochemical performance. It is anticipated that this review will afford enriched information on the rational designs of nanoarchitectures, doping, and heterojunction interfaces for 1D TiO2 based photoelectrodes to achieve highly efficient solar energy conversion.